@article{krantz_low-lying_2009,
title = {Low-lying dielectronic resonances of {Fe} {XXII} for accurate energy determination of autoionising {Rydberg} levels on boronlike cores},
volume = {163},
issn = {1742-6596},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/163/1/012059},
doi = {http://dx.doi.org/10.1088/1742-6596/163/1/012059},
abstract = {We present high resolution measurements of dielectronic recombination
(DR) of Fe XXII forming doubly excited Fe XXI. These measurements were
performed at the Test Storage Ring (TSR) of the Max-Planck-Institute
of Nuclear Physics (MPIK). Low-lying DR resonances allow precise
energy determination of the doubly excited autoionising levels in Fe
XXI and, with suitable future calculations of Rydberg binding energies
(n [?] 7), of 2s22p to 2s2p2 excitation energies of the boronlike Fe
XXII core.},
urldate = {2009-11-13},
journal = {Journal of Physics: Conference Series},
author = {Krantz, C. and Orlov, D. A. and Bernhardt, D. and Brandau, C. and Hoffmann, J. and Muller, A. and Ricsóka, T. and Ricz, S. and Schippers, S. and Wolf, A.},
year = {2009},
pages = {012059},
file = {IOP Snapshot:/home/puma/.zotero_bibliography/storage/QE4T29WA/012059.html:text/html;Krantz et al. - 2009 - Low-lying dielectronic resonances of Fe XXII for a.pdf:/home/puma/.zotero_bibliography/storage/A37XT3IW/Krantz et al. - 2009 - Low-lying dielectronic resonances of Fe XXII for a.pdf:application/pdf}
}
@article{schmidt_electron-ion_2007,
title = {Electron-ion recombination of {Si} {IV} forming {Si} {III}: {Storage}-ring measurement and multiconfiguration {Dirac}-{Fock} calculations},
volume = {76},
shorttitle = {Electron-ion recombination of {Si} {IV} forming {Si} {III}},
url = {http://link.aps.org/abstract/PRA/v76/e032717},
doi = {10.1103/PhysRevA.76.032717},
number = {3},
urldate = {2009-11-13},
journal = {Physical Review A (Atomic, Molecular, and Optical Physics)},
author = {Schmidt, E. W. and Bernhardt, D. and Müller, A. and Schippers, S. and Fritzsche, S. and Hoffmann, J. and Jaroshevich, A. S. and Krantz, C. and Lestinsky, M. and Orlov, D. A. and Wolf, A. and Lukic, D. and Savin, D. W.},
year = {2007},
keywords = {atom-electron collisions, Dirac-Fock calculations, ion recombination, positive ions, silicon},
pages = {032717--12},
file = {Electron-ion recombination of Si IV forming Si III\: Storage-ring measurement and multiconfiguration Dirac-Fock calculations:/home/puma/.zotero_bibliography/storage/A48UTMGA/GetabsServlet.html:text/html;Schmidt et al. - 2007 - Electron-ion recombination of Si IV forming Si III.pdf:/home/puma/.zotero_bibliography/storage/UCCP7STS/Schmidt et al. - 2007 - Electron-ion recombination of Si IV forming Si III.pdf:application/pdf}
}
@article{orlov_high_2009,
title = {High resolution low-energy dielectronic recombination rate coefficients of beryllium-like germanium: {QED} test bench for two-valence-electron systems},
volume = {163},
issn = {1742-6596},
shorttitle = {High resolution low-energy dielectronic recombination rate coefficients of beryllium-like germanium},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/163/1/012058},
doi = {http://dx.doi.org/10.1088/1742-6596/163/1/012058},
abstract = {Low-energy dielectronic recombination resonances of beryllium-like
Ge28+ have been studied by electron collision spectroscopy in the
heavy-ion storage ring TSR using a twin-electron beam technique
combined with an ultracold photoelectron source. Rich resonance
structure below 1.7 eV is observed which mainly arises from resonant
capture of the free electron to 91 Rydberg states accompanied by
excitation of inner valence electrons from the 2s2(1S0) ground state
to 2s2p(1P1). The positions of resonances below 0.3 eV are measured
with an accuracy better than 0.5 meV. Accurate calculations of Rydberg
binding energies for these resonances are still required in order to
derive a precise value for the 1S0 - 1P1 transition energy, which may
give the opportunity for high-accuracy testing of QED corrections to
atomic energy levels for a two valence electron system.},
urldate = {2009-11-13},
journal = {Journal of Physics: Conference Series},
author = {Orlov, D. A. and Krantz, C. and Bernhardt, D. and Brandau, C. and Hoffmann, J. and Müller, A. and Ricsoka, T. and Schippers, S. and Shornikov, A. and Wolf, A.},
year = {2009},
pages = {012058},
file = {IOP Snapshot:/home/puma/.zotero_bibliography/storage/N4AGE95F/012058.html:text/html;Orlov et al. - 2009 - High resolution low-energy dielectronic recombinat.pdf:/home/puma/.zotero_bibliography/storage/RTAJ5C9H/Orlov et al. - 2009 - High resolution low-energy dielectronic recombinat.pdf:application/pdf}
}
@phdthesis{krantz_intense_2009,
title = {Intense {Electron} {Beams} from {GaAs} {Photocathodes} as a {Tool} for {Molecular} and {Atomic} {Physics}},
url = {http://archiv.ub.uni-heidelberg.de/volltextserver/volltexte/2009/10009/},
abstract = {We present cesium-coated GaAs photocathodes as reliable sources of intense, quasi-monoenergetic electron beams in atomic and molecular physics experiments. In long-time operation of the Electron Target of the ion storage ring TSR in Heidelberg, cold electron beams could be realised at steadily improving intensity and reliability. Minimisation of processes degrading the quantum efficiency allowed to increase the extractable current to more than 1mA at stable cathode lifetimes of 24 h or more. The benefits of the cold electron beam with respect to its application to electron cooling and electron-ion recombination experiments are discussed. Benchmark experiments demonstrate the superior cooling force and energy resolution of the photoelectron beam compared to its thermionic counterparts. The long period of operation allowed to study the long-time behaviour of the GaAs samples during multiple usage cycles at the Electron Target and repeated in-vacuum surface cleaning by atomic hydrogen exposure. An electron emission spectroscopy setup has been implemented at the photocathode preparation chamber of the Electron Target. Among others, this new facility opened the way to a novel application of GaAs (Cs) photocathodes as robust, ultraviolet-driven electron emitters. Based on this principle, a prototype of an electron gun, designed for implementation at the HITRAP setup at GSI, has been built and taken into operation successfully.},
urldate = {2009-11-13},
author = {Krantz, Claude},
year = {2009},
keywords = {Photokathode , Elektronenstrahl , Speicherring , Dielektronische Rekombination , Elektronenkühlung , Dissoziative Rekombination , Galliumarsenid , electronbeam , photocathode , gallium-arsenide , electron-cooling , storage-ring},
file = {HeiDOK - Intense Electron Beams from GaAs Photocathodes as a Tool for Molecular and Atomic Physics - Krantz, Claude:/home/puma/.zotero_bibliography/storage/C2HP94JK/10009.html:text/html;Krantz - Intense Electron Beams from GaAs Photocathodes as .pdf:/home/puma/.zotero_bibliography/storage/P78ZXSV3/Krantz - Intense Electron Beams from GaAs Photocathodes as .pdf:application/pdf}
}
@article{novotny_anisotropic_2009,
title = {Anisotropic fragmentation in low-energy dissociative recombination},
volume = {192},
issn = {1742-6596},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/192/1/012024},
doi = {http://dx.doi.org/10.1088/1742-6596/192/1/012024},
abstract = {On a dense energy grid reaching up to 75 meV electron collision energy
the fragmentation angle and the kinetic energy release of neutral
dissociative recombination fragments have been studied in a twin
merged beam experiment. The anisotropy and the extracted rotational
state contributions were found to sensitively depend on energy. Both
show pronounced variations on a likewise narrow energy scale as the
rotationally averaged rate coefficient. For the first time angular
dependences described by Legendre polynomials higher than 2nd order
could be deduced. Moreover, a slight anisotropy at zero collision
energy was observed which is caused by the flattened velocity
distribution of the electron beam.},
urldate = {2009-11-13},
journal = {Journal of Physics: Conference Series},
author = {Novotny, S. and Rubinstein, H. and Buhr, H. and Novotný, O. and Hoffmann, J. and Mendes, M. B. and Orlov, D. A. and Berg, M. H. and Froese, M. and Jaroshevich, A. S. and Jordon-Thaden, B. and Grieser, M. and Krantz, C. and Lange, M. and Lestinsky, M. and Petrignani, A. and Schneider, I. F. and Shafir, D. and Tamo, F. O. Waffeu and Zajfman, D. and Schwalm, D. and Wolf, A.},
year = {2009},
pages = {012024},
file = {Anisotropic fragmentation in low-energy dissociative recombination:/home/puma/.zotero_bibliography/storage/GRKI57TC/012024.html:text/html;IOP Snapshot:/home/puma/.zotero_bibliography/storage/WSZJXNDT/012024.html:text/html;Novotny et al. - 2009 - Anisotropic fragmentation in low-energy dissociati.pdf:/home/puma/.zotero_bibliography/storage/B4I7MQKI/Novotny et al. - 2009 - Anisotropic fragmentation in low-energy dissociati.pdf:application/pdf}
}
@article{petrignani_spectroscopy_2009,
title = {Spectroscopy and dissociative recombination of the lowest rotational states of {H}+3},
volume = {192},
issn = {1742-6596},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/192/1/012022},
doi = {http://dx.doi.org/10.1088/1742-6596/192/1/012022},
abstract = {The dissociative recombination of the lowest rotational states of H3+
has been investigated at the storage ring TSR using a cryogenic
22-pole radiofrequency ion trap as injector. The H3+ was cooled with
buffer gas at [?]15 K to the lowest rotational levels, (J, G)=(1,0)
and (1,1), which belong to the ortho and para proton-spin symmetry,
respectively. The rate coefficients and dissociation dynamics of
H3+(J, G) populations produced with normal-and para-H2 were measured
and compared to the rate and dynamics of a hot H3+ beam from a Penning
source. The production of cold H3+ rotational populations was
separately studied by rovibrational laser spectroscopy using chemical
probing with argon around 55 K. First results indicate a [?]20\%
relative increase of the para contribution when using para-H2 as
parent gas. The H3+ rate coefficient observed for the para-H2 source
gas, however, is quite similar to the H3+ rate for the normal-H2
source gas. The recombination dynamics confirm that for both source
gases, only small populations of rotationally excited levels are
present. The distribution of 3-body fragmentation geometries displays
a broad part of various triangular shapes with an enhancement of
[?]12\% for events with symmetric near-linear configurations. No large
dependences on internal state or collision energy are found.},
urldate = {2009-11-13},
journal = {Journal of Physics: Conference Series},
author = {Petrignani, A. and Kreckel, H. and Berg, M. H. and Altevogt, S. and Bing, D. and Buhr, H. and Froese, M. and Grieser, M. and Hoffmann, J. and Jordon-Thaden, B. and Krantz, C. and Mendes, M. B. and Novotny, O. and Novotny, S. and Orlov, D. A. and Reinhardt, S. and Wolf, A.},
year = {2009},
pages = {012022},
file = {IOP Snapshot:/home/puma/.zotero_bibliography/storage/WBSPRVTP/012022.html:text/html;Petrignani et al. - 2009 - Spectroscopy and dissociative recombination of the.pdf:/home/puma/.zotero_bibliography/storage/STB4KNST/Petrignani et al. - 2009 - Spectroscopy and dissociative recombination of the.pdf:application/pdf}
}
@article{trabert_atomic_2009,
title = {Atomic lifetime measurements on forbidden transitions of {Al}-, {Si}-, {P}- and {S}-like ions at a heavy-ion storage ring},
volume = {42},
issn = {0953-4075},
url = {https://iopscience.iop.org/article/10.1088/0953-4075/42/2/025002},
doi = {http://dx.doi.org/10.1088/0953-4075/42/2/025002},
abstract = {Lifetimes of 3s23pk ground configuration levels of Al-, Si-, P- and
S-like ions of Fe, Co and Ni have been measured at a heavy-ion storage
ring. Some of the observed decay curves show strong evidence of
cascade repopulation from specific 3d levels that feature lifetimes in
the same multi-millisecond range as the levels of the ground
configuration. We identify the foil-stripping process in the ion
production as the cause of the cascade level population and assess the
importance of specific cascades for the measurement technique.},
number = {2},
urldate = {2009-11-13},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Träbert, Elmar and Hoffmann, Jens and Krantz, Claude and Wolf, Andreas and Ishikawa, Yasuyuki and Santana, Juan A.},
year = {2009},
pages = {025002},
file = {IOP Snapshot:/home/puma/.zotero_bibliography/storage/EIKIRTI6/025002.html:text/html;Trabert et al. - 2009 - Atomic lifetime measurements on forbidden transiti.pdf:/home/puma/.zotero_bibliography/storage/7W3QUG4V/Trabert et al. - 2009 - Atomic lifetime measurements on forbidden transiti.pdf:application/pdf}
}
@article{kreckel_electron_2007,
title = {Electron collisions and rovibrational action spectroscopy of cold {H3}+ molecules},
volume = {88},
issn = {1742-6596},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/88/1/012064},
doi = {http://dx.doi.org/10.1088/1742-6596/88/1/012064},
abstract = {Electron recombination of H3+ has found a lot of attention due to its
outstanding relevance for the chemistry of the interstellar medium
(ISM) and its role as a benchmark for the treatment of dissociative
recombination (DR) of polyatomic ions. We report DR measurements
performed at the TSR storage ring utilizing a cryogenic ion trap
injector. Furthermore, a chemical probing spectroscopy technique is
described that allows for a very sensitive monitoring of the populated
states inside the ion injector. Since H3+ exists in two different
nuclear spin modifications, a controlled manipulation of the
ortho/para fraction is needed in order to perform state-selective
measurements.},
urldate = {2009-11-13},
journal = {Journal of Physics: Conference Series},
author = {Kreckel, H. and Petrignani, A. and Berg, M. and Bing, D. and Reinhardt, S. and Altevogt, S. and Buhr, H. and Froese, M. and Hoffmann, J. and Jordon-Thaden, B. and Krantz, C. and Lestinsky, M. and Mendes, M. and Novotny, O. and Novotny, S. and Pedersen, H. B. and Orlov, D. A. and Mikosch, J. and Wester, R. and Plasil, R. and Glosik, J. and Schwalm, D. and Zajfman, D. and Wolf, A.},
year = {2007},
pages = {012064},
file = {IOP Snapshot:/home/puma/.zotero_bibliography/storage/HUVH27ES/012064.html:text/html;Kreckel et al. - 2007 - Electron collisions and rovibrational action spect.pdf:/home/puma/.zotero_bibliography/storage/E3TJHCAS/Kreckel et al. - 2007 - Electron collisions and rovibrational action spect.pdf:application/pdf}
}
@article{spruck_recombination_2014,
title = {Recombination of {W18}+ ions with electrons: {Absolute} rate coefficients from a storage-ring experiment and from theoretical calculations},
volume = {90},
shorttitle = {Recombination of {W18}+ ions with electrons},
url = {http://link.aps.org/doi/10.1103/PhysRevA.90.032715},
doi = {10.1103/PhysRevA.90.032715},
abstract = {We present experimentally measured and theoretically calculated rate coefficients for the electron-ion recombination of W18+([Kr]4d104f10) forming W17+. At low electron-ion collision energies, the merged-beam rate coefficient is dominated by strong, mutually overlapping recombination resonances. In the temperature range where the fractional abundance of W18+ is expected to peak in a fusion plasma, the experimentally derived Maxwellian recombination rate coefficient is 5 to 10 times larger than that which is currently recommended for plasma modeling. The complexity of the atomic structure of the open-4f system under study makes the theoretical calculations extremely demanding. Nevertheless, the results of the present Breit-Wigner partitioned dielectronic recombination calculations agree reasonably well with the experimental findings. This also gives confidence in the ability of the theory to generate sufficiently accurate atomic data for the plasma modeling of other complex ions.},
number = {3},
urldate = {2014-09-26},
journal = {Physical Review A},
author = {Spruck, K. and Badnell, N. R. and Krantz, C. and Novotný, O. and Becker, A. and Bernhardt, D. and Grieser, M. and Hahn, M. and Repnow, R. and Savin, D. W. and Wolf, A. and Müller, A. and Schippers, S.},
month = sep,
year = {2014},
pages = {032715},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/XMRJAEC8/PhysRevA.90.html:text/html;Spruck et al. - 2014 - Recombination of W18+ ions with electrons Absolut.pdf:/home/puma/.zotero_bibliography/storage/PJJM9K66/Spruck et al. - 2014 - Recombination of W18+ ions with electrons Absolut.pdf:application/pdf}
}
@article{orlov_long_2009,
title = {Long term operation of high quantum efficiency {GaAs}({Cs},{O}) photocathodes using multiple recleaning by atomic hydrogen},
volume = {106},
issn = {00218979},
url = {http://link.aip.org/link/JAPIAU/v106/i5/p054907/s1&Agg=doi},
doi = {10.1063/1.3208054},
number = {5},
urldate = {2010-08-11},
journal = {Journal of Applied Physics},
author = {Orlov, D. A. and Krantz, C. and Wolf, A. and Jaroshevich, A. S. and Kosolobov, S. N. and Scheibler, H. E. and Terekhov, A. S.},
year = {2009},
pages = {054907},
file = {Orlov et al. - 2009 - Long term operation of high quantum efficiency GaA.pdf:/home/puma/.zotero_bibliography/storage/XG5I3JTM/Orlov et al. - 2009 - Long term operation of high quantum efficiency GaA.pdf:application/pdf}
}
@article{stutzel_fragmentation_2009,
title = {Fragmentation by electron {Recombination} for {HF}+ and {CF}+},
volume = {194},
issn = {1742-6596},
shorttitle = {{\textless}title xmlns="http},
url = {http://iopscience.iop.org/1742-6596/194/6/062028/},
doi = {10.1088/1742-6596/194/6/062028},
number = {6},
urldate = {2010-08-11},
journal = {Journal of Physics: Conference Series},
author = {Stützel, J. and Novotný, O. and Novotny, S. and Orlov, D. A. and Buhr, H. and Mendes, M. B. and Greene, C. and Hoffmann, J. and Krantz, C. and Altevogt, S and Berg, M. H. and Bing, D. and Froese, M. and Grieser, M. and Jordon-Thaden, B. and Lange, M. and Lestinsky, M. and Petrignani, A. and Shornikov, A. and Wolf, A.},
month = nov,
year = {2009},
pages = {062028},
file = {Fragmentation by electron recombination for HF+ and CF+:/home/puma/.zotero_bibliography/storage/3EPIKHCV/062028.html:text/html;Stützel et al. - 2009 - Fragmentation by electron Recombination for HF+ an.pdf:/home/puma/.zotero_bibliography/storage/QENEJM92/Stützel et al. - 2009 - Fragmentation by electron Recombination for HF+ an.pdf:application/pdf}
}
@article{petrignani_ultraviolet_2010,
title = {Ultraviolet and {Visible} {Light} {Photodissociation} of {H3}+ in an {Ion} {Storage} {Ring}},
volume = {114},
url = {http://dx.doi.org/10.1021/jp9104163},
doi = {10.1021/jp9104163},
abstract = {Ultraviolet and visible photodissociation of a vibrationally excited H3+ ion beam, as produced by standard ion sources, was successfully implemented in an ion storage ring with the aim of investigating the decay of the excited molecular levels. A collinear beams configuration was used to measure the photodissociation of H3+ into H2+ + H fragments by transitions into the first excited singlet state with 266 and 532 nm laser beams. A clear signal could be observed up to 5 ms of storage, indicating that enough highly excited rovibrational states survive on the millisecond time scale of the experiment. The decay into H2+ + H shows an effective time constant between about 1 and 1.5 ms. The initial photodissociating states are estimated to lie roughly 1 eV below the dissociation limit of 4.4 eV. The expected low population of these levels gives rise to an effective cross section of several 10−20 cm2 for ultraviolet and some 10−21 cm2 for visible light. For using multistep resonant dissociation schemes to monitor rotational populations of cold H3+ in low-density environments, these measurements open promising perspectives.},
number = {14},
urldate = {2010-08-11},
journal = {The Journal of Physical Chemistry A},
author = {Petrignani, A. and Bing, D. and Novotný, O. and Berg, M. H. and Buhr, H. and Grieser, M. and Jordon-Thaden, B. and Krantz, C. and Mendes, M. B. and Menk, S. and Novotny, S. and Orlov, D. A. and Repnow, R. and Stützel, J. and Urbain, X. and Wolf, A.},
month = apr,
year = {2010},
pages = {4864--4869},
annote = {PMID: 20099872},
file = {ACS Full Text Snapshot:/home/puma/.zotero_bibliography/storage/QSZAPUS5/jp9104163.html:text/html;Petrignani et al. - 2010 - Ultraviolet and Visible Light Photodissociation of.pdf:/home/puma/.zotero_bibliography/storage/P7Z45CVA/Petrignani et al. - 2010 - Ultraviolet and Visible Light Photodissociation of.pdf:application/pdf;Ultraviolet and Visible Light Photodissociation of H3+ in an Ion Storage Ring† - The Journal of Physical Chemistry A (ACS Publications):/home/puma/.zotero_bibliography/storage/37NWPSN7/jp9104163.html:text/html}
}
@article{orlov_electron_2007,
title = {Electron {Cooling} with {Photocathode} {Electron} {Beams} {Applied} to slow ions at {TSR} and {CSR}.},
url = {https://accelconf.web.cern.ch/AccelConf/cl07/PAPERS/FRM1C03.PDF},
abstract = {We report electron cooling experiments using a cold
electron beam of 53 eV produced by a cryogenic GaAs
photocathode. With this device a beam of CF+ (mass 31)
of only 97 keV/u (3 MeV) was cooled down to a very
small equilibrium beam size of about 0.04×0.2 mm2. A
transverse cooling time below 2 seconds was obtained.},
journal = {Proceedings of the COOL07 Workshop on Beam Cooling and Related Topics},
author = {Orlov, D. A. and Fadil, H. and Grieser, M. and Krantz, C. and Hoffmann, J. and Novotný, O. and Novotny, S. and Wolf, A.},
year = {2007},
pages = {FRM1C03},
file = {Orlov et al. - 2007 - Electron Cooling with Photocathode Electron Beams .pdf:/home/puma/.zotero_bibliography/storage/Z49IRH7H/Orlov et al. - 2007 - Electron Cooling with Photocathode Electron Beams .pdf:application/pdf}
}
@article{buhr_hot_2010,
title = {Hot {Water} {Molecules} from {Dissociative} {Recombination} of {D3O}+ with {Cold} {Electrons}},
volume = {105},
url = {http://link.aps.org/doi/10.1103/PhysRevLett.105.103202},
doi = {10.1103/PhysRevLett.105.103202},
abstract = {Individual product channels in the dissociative recombination of deuterated hydronium ions and cold electrons are studied in an ion storage ring by velocity imaging using spatial and mass-sensitive detection of the neutral reaction fragments. Initial and final molecular excitation are analyzed, finding the outgoing water molecules to carry internal excitation of more than 3 eV in 90\% of the recombination events. Initial rotation is found to be substantial and in three-body breakup strongly asymmetric energy repartition among the deuterium products is enhanced for hot parent ions.},
number = {10},
urldate = {2010-09-09},
journal = {Physical Review Letters},
author = {Buhr, H. and Stützel, J. and Mendes, M. B. and Novotný, O. and Schwalm, D. and Berg, M. H. and Bing, D. and Grieser, M. and Heber, O. and Krantz, C. and Menk, S. and Novotny, S. and Orlov, D. A. and Petrignani, A. and Rappaport, M. L. and Repnow, R. and Zajfman, D. and Wolf, A.},
year = {2010},
pages = {103202},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/ZA6BHCWU/e103202.html:text/html;Buhr et al. - 2010 - Hot Water Molecules from Dissociative Recombinatio.pdf:/home/puma/.zotero_bibliography/storage/FKEWW9P7/Buhr et al. - 2010 - Hot Water Molecules from Dissociative Recombinatio.pdf:application/pdf}
}
@article{kreckel_high-resolution_2010,
title = {High-resolution storage-ring measurements of the dissociative recombination of {H}\_\{3\}{\textasciicircum}\{+\} using a supersonic expansion ion source},
volume = {82},
url = {http://link.aps.org/doi/10.1103/PhysRevA.82.042715},
doi = {10.1103/PhysRevA.82.042715},
abstract = {We have performed measurements of the dissociative electron recombination (DR) of H3+ at the ion storage ring TSR utilizing a supersonic expansion ion source. The ion source has been characterized by continuous wave cavity ring-down spectroscopy. We present high-resolution DR rate coefficients for different nuclear spin modifications of H3+ combined with precise fragment imaging studies of the internal excitation of the H3+ ions inside the storage ring. The measurements resolve changes in the energy dependence between the ortho-H3+ and para-H3+ rate coefficients at low center-of-mass collision energies. Analysis of the imaging data indicates that the stored H3+ ions may have higher rotational temperatures than previously assumed, most likely due to collisional heating during the extraction of the ions from the ion source. Simulations of the ion extraction shed light on possible origins of the heating process and how to avoid it in future experiments.},
number = {4},
urldate = {2011-01-21},
journal = {Physical Review A},
author = {Kreckel, Holger and Novotný, Oldrich and Crabtree, Kyle N. and Buhr, Henrik and Petrignani, Annemieke and Tom, Brian A. and Thomas, Richard D. and Berg, Max H. and Bing, Dennis and Grieser, Manfred and Krantz, Claude and Lestinsky, Michael and Mendes, Mario B. and Nordhorn, Christian and Repnow, Roland and Stützel, Julia and Wolf, Andreas and McCall, Benjamin J.},
month = oct,
year = {2010},
pages = {042715},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/CS57JTS6/e042715.html:text/html;Kreckel et al. - 2010 - High-resolution storage-ring measurements of the d.pdf:/home/puma/.zotero_bibliography/storage/HM9HHMZP/Kreckel et al. - 2010 - High-resolution storage-ring measurements of the d.pdf:application/pdf}
}
@article{krantz_enhanced_2011,
title = {Enhanced {Schottky} signals from electron-cooled, coasting beams in a heavy-ion storage ring},
volume = {629},
issn = {0168-9002},
url = {http://www.sciencedirect.com/science/article/B6TJM-51PRY1K-C/2/1471bb004f8f4293cea34425a1b8c392},
doi = {10.1016/j.nima.2010.12.034},
abstract = {Measurements at the Test Storage Ring of the Max-Planck-Institut für Kernphysik in Heidelberg (Germany) have shown that the signal amplitude induced in a Schottky-noise pickup electrode by a coasting electron-cooled ion beam can be greatly enhanced by exposure of the latter to a perturbing radiofrequency signal which is detuned from the true beam revolution frequency. The centre frequencies obtained from harmonic analysis of the observed pickup signal closely follow those imposed on the ions by the electron cooling force. The phenomenon can be exploited to measure the true revolution frequency of ion beams of very low intensity, whose pure Schottky noise is too weak to be measurable under normal circumstances.},
number = {1},
urldate = {2011-01-28},
journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
author = {Krantz, C. and Blaum, K. and Grieser, M. and Litvinov, Yu.A. and Repnow, R. and Wolf, A.},
month = feb,
year = {2011},
keywords = {Electron cooling, Storage ring, Schottky noise},
pages = {1--5},
file = {Krantz et al. - 2011 - Enhanced Schottky signals from electron-cooled, co.pdf:/home/puma/.zotero_bibliography/storage/M4HQK7WQ/Krantz et al. - 2011 - Enhanced Schottky signals from electron-cooled, co.pdf:application/pdf;ScienceDirect Snapshot:/home/puma/.zotero_bibliography/storage/V339GIMD/Krantz et al. - 2011 - Enhanced Schottky signals from electron-cooled, co:}
}
@article{krantz_cryogenic_2011,
title = {The {Cryogenic} {Storage} {Ring} and its application to molecular ion recombination physics},
volume = {300},
issn = {1742-6596},
url = {http://iopscience.iop.org/1742-6596/300/1/012010},
doi = {10.1088/1742-6596/300/1/012010},
urldate = {2011-07-21},
journal = {Journal of Physics: Conference Series},
author = {Krantz, C and Berg, F and Blaum, K and Fellenberger, F and Froese, M and Grieser, M and Hahn, R von and Lange, M and Laux, F and Menk, S and Repnow, R and Shornikov, A and Wolf, A},
month = jul,
year = {2011},
pages = {012010},
file = {Krantz et al. - 2011 - The Cryogenic Storage Ring and its application to .pdf:/home/puma/.zotero_bibliography/storage/PAVDW2JD/Krantz et al. - 2011 - The Cryogenic Storage Ring and its application to .pdf:application/pdf;The Cryogenic Storage Ring and its application to molecular ion recombination physics:/home/puma/.zotero_bibliography/storage/JN7BTVJ4/012010.html:text/html}
}
@article{schippers_storage-ring_2012,
title = {Storage-ring measurement of the hyperfine-induced 2s2p {3P0}→2s2 {1S0} transition rate in berylliumlike sulfur},
volume = {85},
url = {http://link.aps.org/doi/10.1103/PhysRevA.85.012513},
doi = {10.1103/PhysRevA.85.012513},
abstract = {The hyperfine-induced 2s 2p 3 P0→2s2 1 S0 transition rate in Be-like sulfur was measured by monitoring the decay of isotopically pure beams of 32S12+ and 33S12+ ions in a heavy-ion storage ring. Within the 4\% experimental uncertainty the experimental value of 0.096(4) s−1 agrees with the most recent theoretical results of [ Cheng et al. Phys. Rev. A 77 052504 (2008)] and [ Andersson et al. Phys. Rev. A 79 032501 (2009)]. Repeated experiments with different magnetic fields in the storage-ring bending magnets demonstrate that artificial quenching of the 2s 2p 3 P0 state by these magnetic fields is negligible.},
number = {1},
urldate = {2012-01-20},
journal = {Physical Review A},
author = {Schippers, S. and Bernhardt, D. and Müller, A. and Lestinsky, M. and Hahn, M. and Novotný, O. and Savin, D. W. and Grieser, M. and Krantz, C. and Repnow, R. and Wolf, A.},
month = jan,
year = {2012},
pages = {012513},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/D86JBU67/e012513.html:text/html;Schippers et al. - 2012 - Storage-ring measurement of the hyperfine-induced .pdf:/home/puma/.zotero_bibliography/storage/73ZITQWM/Schippers et al. - 2012 - Storage-ring measurement of the hyperfine-induced .pdf:application/pdf}
}
@article{mendes_cold_2012,
title = {Cold {Electron} {Reactions} {Producing} the {Energetic} {Isomer} of {Hydrogen} {Cyanide} in {Interstellar} {Clouds}},
volume = {746},
issn = {2041-8205, 2041-8213},
url = {http://iopscience.iop.org/2041-8205/746/1/L8},
doi = {10.1088/2041-8205/746/1/L8},
number = {1},
urldate = {2012-01-23},
journal = {The Astrophysical Journal},
author = {Mendes, Mario B. and Buhr, Henrik and Berg, Max H. and Froese, Michael and Grieser, Manfred and Heber, Oded and Jordon-Thaden, Brandon and Krantz, Claude and Novotný, Oldřich and Novotny, Steffen and Orlov, Dmitry A. and Petrignani, Annemieke and Rappaport, Michael L. and Repnow, Roland and Schwalm, Dirk and Shornikov, Andrey and Stützel, Julia and Zajfman, Daniel and Wolf, Andreas},
month = feb,
year = {2012},
pages = {L8},
file = {Mendes et al. - 2012 - Cold Electron Reactions Producing the Energetic Is.pdf:/home/puma/.zotero_bibliography/storage/TNP636MU/Mendes et al. - 2012 - Cold Electron Reactions Producing the Energetic Is.pdf:application/pdf}
}
@article{schippers_dielectronic_2011,
title = {Dielectronic recombination of xenonlike tungsten ions},
volume = {83},
doi = {10.1103/PhysRevA.83.012711},
abstract = {Dielectronic recombination (DR) of xenonlike W20+ forming W19+ has been studied experimentally at a heavy-ion storage ring. A merged-beams method has been employed for obtaining absolute rate coefficients for electron-ion recombination in the collision-energy range 0–140 eV. The measured rate coefficient is dominated by strong DR resonances even at the lowest experimental energies. At plasma temperatures where the fractional abundance of W20+ is expected to peak in a fusion plasma, the experimentally derived plasma recombination rate coefficient is over a factor of 4 larger than the theoretically calculated rate coefficient which is currently used in fusion plasma modeling. The largest part of this discrepancy stems most probably from the neglect in the theoretical calculations of DR associated with fine-structure excitations of the W20+([Kr]4d10 4f8) ion core.},
number = {1},
urldate = {2012-02-07},
journal = {Physical Review A},
author = {Schippers, S. and Bernhardt, D. and Müller, A. and Krantz, C. and Grieser, M. and Repnow, R. and Wolf, A. and Lestinsky, M. and Hahn, M. and Novotný, O. and Savin, D. W.},
month = jan,
year = {2011},
pages = {012711},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/ECWAUG83/e012711.html:text/html;Schippers et al. - 2011 - Dielectronic recombination of xenonlike tungsten i.pdf:/home/puma/.zotero_bibliography/storage/R2BTHD9N/Schippers et al. - 2011 - Dielectronic recombination of xenonlike tungsten i.pdf:application/pdf}
}
@article{wolf_low-energy_2009,
title = {Low-energy collisions with atomic and molecular ions in a photocathode electron target},
volume = {194},
issn = {1742-6596},
url = {http://iopscience.iop.org/1742-6596/194/1/012024},
doi = {10.1088/1742-6596/194/1/012024},
number = {1},
urldate = {2012-02-07},
journal = {Journal of Physics: Conference Series},
author = {Wolf, A. and Orlov, D. A. and Krantz, C. and Lestinsky, M. and Shornikov, A. and Novotný, O. and Stützel, J. and Buhr, H. and Mendes, M. and Petrignani, A and Grieser, M. and Schippers, S. and Müller, A. and Ferro, F. and Lindroth, E.},
month = nov,
year = {2009},
pages = {012024},
file = {Wolf et al. - 2009 - Low-energy collisions with atomic and molecular io.pdf:/home/puma/.zotero_bibliography/storage/T24NH44W/Wolf et al. - 2009 - Low-energy collisions with atomic and molecular io.pdf:application/pdf}
}
@article{novotny_fragmentation_2010,
title = {Fragmentation {Channels} in {Dissociative} {Electron} {Recombination} with {Hydronium} and {Other} {Astrophysically} {Important} {Species}},
volume = {114},
issn = {1089-5639},
url = {http://dx.doi.org/10.1021/jp9104097},
doi = {10.1021/jp9104097},
abstract = {We report on our recent studies of dissociative recombination (DR) employing two different fragment imaging detection techniques at the TSR storage ring in Heidelberg, Germany. Principles of an upgraded 3D optical system and the new energy-sensitive multistrip detector (EMU) are explained together with possible applications in reaction dynamics studies. With the EMU imaging detector we succeeded to observe the branching ratios after DR of deuterated hydronium ions D3O+ at energies of 0?0.5 and 4?21 eV. The branching ratios are almost constant at low energies while above 6 eV both oxygen-producing channels O + D + D + D and O + D2 + D strongly increase and dominate by about 85\% at 11 eV. To demonstrate further capabilities of our fragment imaging detectors, we also summarize some of our additional recent studies on DR of molecular ions important for astrophysics as well as for fundamental unimolecular dynamics.
We report on our recent studies of dissociative recombination (DR) employing two different fragment imaging detection techniques at the TSR storage ring in Heidelberg, Germany. Principles of an upgraded 3D optical system and the new energy-sensitive multistrip detector (EMU) are explained together with possible applications in reaction dynamics studies. With the EMU imaging detector we succeeded to observe the branching ratios after DR of deuterated hydronium ions D3O+ at energies of 0?0.5 and 4?21 eV. The branching ratios are almost constant at low energies while above 6 eV both oxygen-producing channels O + D + D + D and O + D2 + D strongly increase and dominate by about 85\% at 11 eV. To demonstrate further capabilities of our fragment imaging detectors, we also summarize some of our additional recent studies on DR of molecular ions important for astrophysics as well as for fundamental unimolecular dynamics.},
number = {14},
journal = {The Journal of Physical Chemistry A},
author = {Novotný, Oldřich and Buhr, Henrik and Stützel, Julia and Mendes, Mario B. and Berg, Max H. and Bing, Dennis and Froese, Michael and Grieser, Manfred and Heber, Oded and Jordon-Thaden, Brandon and Krantz, Claude and Lange, Michael and Lestinsky, Michael and Novotny, Steffen and Menk, Sebastian and Orlov, Dmitry A. and Petrignani, Annemieke and Rappaport, Michael L. and Shornikov, Andrey and Schwalm, Dirk and Zajfman, Daniel and Wolf, Andreas},
year = {2010},
pages = {4870--4874},
file = {ACS Full Text Snapshot:/home/puma/.zotero_bibliography/storage/ANB87Z3S/jp9104097.html:text/html;Fragmentation Channels in Dissociative Electron Recombination with Hydronium and Other Astrophysically Important Species†:/home/puma/.zotero_bibliography/storage/TNXSX37W/jp9104097.html:text/html;Novotný et al. - 2010 - Fragmentation Channels in Dissociative Electron Re.pdf:/home/puma/.zotero_bibliography/storage/TT5IRCHV/Novotný et al. - 2010 - Fragmentation Channels in Dissociative Electron Re.pdf:application/pdf}
}
@article{lestinsky_experimental_2009,
title = {Experimental studies of electron collisions with atomic ions for astrophysical plasmas},
volume = {194},
issn = {1742-6596},
url = {http://iopscience.iop.org/1742-6596/194/6/062025},
doi = {10.1088/1742-6596/194/6/062025},
number = {6},
urldate = {2012-02-07},
journal = {Journal of Physics: Conference Series},
author = {Lestinsky, Michael and Badnell, Nigel R and Bernhard, Dietrich and Borovyk, Oleksandr and Grieser, Manfred and Hoffmann, Jens and Krantz, Claude and Lukić, Dragan V and Müller, Alfred and Orlov, Dmitry A and Savin, Daniel Wolf and Schmid, Eike W and Schippers, Stefan and Wolf, Andreas},
month = nov,
year = {2009},
pages = {062025},
file = {Lestinsky et al. - 2009 - Experimental studies of electron collisions with a.pdf:/home/puma/.zotero_bibliography/storage/7MRP3UJJ/Lestinsky et al. - 2009 - Experimental studies of electron collisions with a.pdf:application/pdf}
}
@article{von_hahn_electrostatic_2011,
title = {The electrostatic {Cryogenic} {Storage} {Ring} {CSR} – {Mechanical} concept and realization},
volume = {269},
issn = {0168-583X},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X11003843},
doi = {10.1016/j.nimb.2011.04.033},
abstract = {A new and technologically challenging project, the electrostatic Cryogenic Storage Ring CSR, is presently under construction at the Max-Planck-Institute for Nuclear Physics in Heidelberg. Applying liquid helium cooling, the CSR, with 35\&\#xa0;m circumference, will provide a low temperature environment of only a few Kelvin and an extremely high vacuum of better than 10−13\&\#xa0;mbar. To realize these conditions the mechanical design has been completed and now the first quarter section is in the construction phase. For the onion skin structure of the cryogenic system we have at the outer shell the cryostat chambers, realized by welded rectangular stainless steel frames with aluminum plates. The next two shells are fabricated as aluminum shields kept at 80 and 40\&\#xa0;K. The inner vacuum chambers for the experimental vacuum consist of stainless steel chambers cladded with external copper sheets connected to the LHe lines for optimized thermal equilibration and cryopumping. Additional large surface 2\&\#xa0;K units are installed for cryogenic pumping of H2. The mechanical concepts and the realization will be presented in detail.},
number = {24},
urldate = {2012-02-07},
journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
author = {von Hahn, R. and Berg, F. and Blaum, K. and Crespo Lopez-Urrutia, J.R. and Fellenberger, F. and Froese, M. and Grieser, M. and Krantz, C. and Kühnel, K.-U. and Lange, M. and Menk, S. and Laux, F. and Orlov, D.A. and Repnow, R. and Schröter, C.D. and Shornikov, A. and Sieber, T. and Ullrich, J. and Wolf, A. and Rappaport, M. and Zajfman, D.},
month = dec,
year = {2011},
keywords = {Storage ring, Electrostatic, Cryogenic, Extreme UHV, Liquid helium},
pages = {2871--2874},
file = {ScienceDirect Snapshot:/home/puma/.zotero_bibliography/storage/DDWMVCF7/von Hahn et al. - 2011 - The electrostatic Cryogenic Storage Ring CSR – Mec:;von Hahn et al. - 2011 - The electrostatic Cryogenic Storage Ring CSR – Mec.pdf:/home/puma/.zotero_bibliography/storage/3G3XID4Q/von Hahn et al. - 2011 - The electrostatic Cryogenic Storage Ring CSR – Mec.pdf:application/pdf}
}
@article{hahn_storage_2011,
title = {Storage {Ring} {Cross} {Section} {Measurements} for {Electron} {Impact} {Ionization} of {Fe11}+ {Froming} {Fe12}+ and {Fe13}+},
volume = {729},
issn = {0004-637X, 1538-4357},
url = {http://iopscience.iop.org/0004-637X/729/1/76/},
doi = {10.1088/0004-637X/729/1/76},
number = {1},
urldate = {2012-02-07},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Bernhardt, D. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = mar,
year = {2011},
pages = {76},
file = {Hahn et al. - 2011 - Storage Ring Cross Section Measurements for Electr.pdf:/home/puma/.zotero_bibliography/storage/I9FHXCZM/Hahn et al. - 2011 - Storage Ring Cross Section Measurements for Electr.pdf:application/pdf;Storage Ring Cross Section Measurements for Electron Impact Ionization of Fe11+ Forming Fe12+ and Fe13+:/home/puma/.zotero_bibliography/storage/E8MCVJRK/76.html:text/html}
}
@article{petrignani_resonant_2011,
title = {Resonant structure of low-energy {H3}+ dissociative recombination},
volume = {83},
url = {http://link.aps.org/doi/10.1103/PhysRevA.83.032711},
doi = {10.1103/PhysRevA.83.032711},
abstract = {High-resolution dissociative recombination rate coefficients of rotationally cool and hot H3+ in the vibrational ground state have been measured with a 22-pole trap setup and a Penning ion source, respectively, at the ion storage-ring TSR. The experimental results are compared with theoretical calculations to explore the dependence of the rate coefficient on ion temperature and to study the contributions of different symmetries to probe the rich predicted resonance spectrum. The kinetic energy release was investigated by fragment imaging to derive internal temperatures of the stored parent ions under differing experimental conditions. A systematic experimental assessment of heating effects is performed which, together with a survey of other recent storage-ring data, suggests that the present rotationally cool rate-coefficient measurement was performed at 380-130+50 K and that this is the lowest rotational temperature so far realized in storage-ring rate-coefficient measurements on H3+. This partially supports the theoretical suggestion that temperatures higher than assumed in earlier experiments are the main cause for the large gap between the experimental and the theoretical rate coefficients. For the rotationally hot rate-coefficient measurement a temperature of below 3250 K is derived. From these higher-temperature results it is found that increasing the rotational ion temperature in the calculations cannot fully close the gap between the theoretical and the experimental rate coefficients.},
number = {3},
urldate = {2012-02-07},
journal = {Physical Review A},
author = {Petrignani, Annemieke and Altevogt, Simon and Berg, Max H. and Bing, Dennis and Grieser, Manfred and Hoffmann, Jens and Jordon-Thaden, Brandon and Krantz, Claude and Mendes, Mario B. and Novotný, Oldřich and Novotny, Steffen and Orlov, Dmitry A. and Repnow, Roland and Sorg, Tobias and Stützel, Julia and Wolf, Andreas and Buhr, Henrik and Kreckel, Holger and Kokoouline, Viatcheslav and Greene, Chris H.},
month = mar,
year = {2011},
pages = {032711},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/IC5ZKPKT/e032711.html:text/html;Petrignani et al. - 2011 - Resonant structure of low-energy H_ 3 ^ + dissoci.pdf:/home/puma/.zotero_bibliography/storage/MT34UXU8/Petrignani et al. - 2011 - Resonant structure of low-energy H_ 3 ^ + dissoci.pdf:application/pdf}
}
@article{hahn_electron-impact-ionization_2012,
title = {Electron-impact-ionization measurements using hyperfine-assisted state preparation of ground-state berylliumlike sulfur},
volume = {85},
url = {http://link.aps.org/doi/10.1103/PhysRevA.85.042713},
doi = {10.1103/PhysRevA.85.042713},
abstract = {We have measured electron impact ionization (EII) of the beryllium-like ion S12+. The use of an isotopically pure A=33 beam of S12+ ions is established as a method to eliminate all metastable levels, including the extremely long-lived metastable level 2s2p 3 P0, which, for this isotope, decays by hyperfine-induced radiative transitions. The energy dependence and absolute size of the EII cross section were measured from the resulting pure ground-state population at energies from below the threshold at ≈ 652.2 eV up to 3000 eV. These data provide an experimental benchmark for theory.},
number = {4},
urldate = {2012-04-13},
journal = {Physical Review A},
author = {Hahn, M. and Bernhardt, D. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = apr,
year = {2012},
pages = {042713},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/2HNB7BT8/Hahn et al. - 2012 - Electron-impact-ionization measurements using hype.html:text/html;Hahn et al. - 2012 - Electron-impact-ionization measurements using hype.pdf:/home/puma/.zotero_bibliography/storage/KZHC5MN5/Hahn et al. - 2012 - Electron-impact-ionization measurements using hype.pdf:application/pdf}
}
@article{novotny_electron-ion_2012,
title = {Electron-{Ion} {Recombination} of {Fe} {XII} forming {Fe} {XI}: {Laboratory} {Measurements} and {Theoretical} {Calculations}},
volume = {753},
issn = {0004-637X, 1538-4357},
shorttitle = {{ELECTRON}-{ION} {RECOMBINATION} {OF} {Fe} {XII} {FORMING} {Fe} {XI}},
url = {http://iopscience.iop.org/0004-637X/753/1/57},
doi = {10.1088/0004-637X/753/1/57},
number = {1},
urldate = {2012-06-14},
journal = {The Astrophysical Journal},
author = {Novotný, O. and Badnell, N. R. and Bernhardt, D. and Grieser, M. and Hahn, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Repnow, R. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = jul,
year = {2012},
pages = {57},
file = {Novotný et al. - 2012 - ELECTRON-ION RECOMBINATION OF Fe XII FORMING Fe XI.pdf:/home/puma/.zotero_bibliography/storage/QW99NI5H/Novotný et al. - 2012 - ELECTRON-ION RECOMBINATION OF Fe XII FORMING Fe XI.pdf:application/pdf}
}
@article{krantz_pulsed_2010,
title = {A {Pulsed} {Electron} {Source} for the {HITRAP} {Cooler} {Trap}},
volume = {2009},
url = {http://repository.gsi.de/record/53522/files/GSI-Report-2010-1.pdf?version=1},
urldate = {2014-09-28},
journal = {GSI Scientific Report},
author = {Krantz, C. and Orlov, D. A. and Wolf, A. and Herfurth, F. and Kester, O.},
year = {2010},
pages = {375},
file = {Krantz et al. - A Pulsed Electron Source for the HITRAP Cooler Tra.pdf:/home/puma/.zotero_bibliography/storage/GS4NHITH/Krantz et al. - A Pulsed Electron Source for the HITRAP Cooler Tra.pdf:application/pdf}
}
@article{lestinsky_electron-ion_2012,
title = {Electron-{Ion} {Recombination} of {Mg6}+ forming {Mg5}+ and of {Mg7}+ forming {Mg6}+: {Laboratory} {Measurements} and {Theoretical} {Calculations}},
volume = {758},
issn = {0004-637X, 1538-4357},
shorttitle = {{ELECTRON}-{ION} {RECOMBINATION} {OF} {Mg} 6 + {FORMING} {Mg} 5 + {AND} {OF} {Mg} 7 + {FORMING} {Mg} 6 +},
url = {http://iopscience.iop.org/0004-637X/758/1/40},
doi = {10.1088/0004-637X/758/1/40},
number = {1},
urldate = {2012-09-27},
journal = {The Astrophysical Journal},
author = {Lestinsky, M. and Badnell, N. R. and Bernhardt, D. and Bing, D. and Grieser, M. and Hahn, M. and Hoffmann, J. and Jordon-Thaden, B. and Krantz, C. and Novotný, O. and Orlov, D. A. and Repnow, R. and Shornikov, A. and Müller, A. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = oct,
year = {2012},
pages = {40},
file = {Lestinsky et al. - 2012 - Electron-Ion Recombination of Mg6+ forming Mg5+ an.pdf:/home/puma/.zotero_bibliography/storage/T33HBAGT/Lestinsky et al. - 2012 - Electron-Ion Recombination of Mg6+ forming Mg5+ an.pdf:application/pdf}
}
@article{trabert_isoelectronic_2012,
title = {Isoelectronic trends of the {E1}-forbidden decay rates of {Al}-, {Si}-, {P}-, and {S}-like ions of {Cl}, {Ti}, {Mn}, {Cu}, and {Ge}},
volume = {45},
issn = {0953-4075, 1361-6455},
url = {http://stacks.iop.org/0953-4075/45/i=21/a=215003?key=crossref.da52669db170e839cb10b5eecac88c45},
doi = {10.1088/0953-4075/45/21/215003},
number = {21},
urldate = {2012-10-31},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Träbert, Elmar and Grieser, Manfred and Krantz, Claude and Repnow, Roland and Wolf, Andreas and Diaz, Francisco J and Ishikawa, Yasuyuki and Santana, Juan A},
month = nov,
year = {2012},
pages = {215003},
file = {Träbert et al. - 2012 - Isoelectronic trends of the E1-forbidden decay rat.pdf:/home/puma/.zotero_bibliography/storage/7P847K4G/Träbert et al. - 2012 - Isoelectronic trends of the E1-forbidden decay rat.pdf:application/pdf}
}
@article{novotny_astrochemistry_2012,
title = {Astrochemistry in an {Ion} {Storage} {Ring}},
volume = {388},
issn = {1742-6588, 1742-6596},
url = {http://iopscience.iop.org/1742-6596/388/1/012012},
doi = {10.1088/1742-6596/388/1/012012},
number = {1},
urldate = {2012-11-13},
journal = {Journal of Physics: Conference Series},
author = {Novotný, O and Berg, M H and Buhr, H and Froese, M and Geppert, W and Grieser, M and Grussie, F and Hamberg, M and Krantz, C and Lestinsky, M and Mendes, M and Nordhorn, C and Novotny, S and Orlov, D A and Petrignani, A and Shornikov, A and Stützel, J and Schwalm, D and Savin, D W and Wolf, A},
month = nov,
year = {2012},
pages = {012012},
file = {Novotný et al. - 2012 - Astrochemistry in an Ion Storage Ring.pdf:/home/puma/.zotero_bibliography/storage/CRMEKWSR/Novotný et al. - 2012 - Astrochemistry in an Ion Storage Ring.pdf:application/pdf}
}
@article{buhr_energy-sensitive_2010,
title = {Energy-sensitive imaging detector applied to the dissociative recombination of {D2H}+},
volume = {81},
url = {http://link.aps.org/doi/10.1103/PhysRevA.81.062702},
doi = {10.1103/PhysRevA.81.062702},
abstract = {We report on an energy-sensitive imaging detector for studying the fragmentation of polyatomic molecules in the dissociative recombination of fast molecular ions with electrons. The system is based on a large area (10×10 cm2) position-sensitive, double-sided Si-strip detector with 128 horizontal and 128 vertical strips, whose pulse height information is read out individually. The setup allows us to uniquely identify fragment masses and is thus capable of measuring branching ratios between different fragmentation channels, kinetic energy releases, and breakup geometries as a function of the relative ion-electron energy. The properties of the detection system, which has been installed at the Test Storage Ring (TSR) facility of the Max-Planck Institute for Nuclear Physics in Heidelberg, is illustrated by an investigation of the dissociative recombination of the deuterated triatomic hydrogen cation D2H+. A huge isotope effect is observed when comparing the relative branching ratio between the D2 + H and the HD + D channel; the ratio 2B(D2 + H)/B(HD + D), which is measured to be 1.27±0.05 at relative electron-ion energies around 0 eV, is found to increase to 3.7±0.5 at {\textasciitilde}5 eV.},
number = {6},
urldate = {2014-09-30},
journal = {Physical Review A},
author = {Buhr, H. and Mendes, M. B. and Novotný, O. and Schwalm, D. and Berg, M. H. and Bing, D. and Heber, O. and Krantz, C. and Orlov, D. A. and Rappaport, M. L. and Sorg, T. and Stützel, J. and Varju, J. and Wolf, A. and Zajfman, D.},
month = jun,
year = {2010},
pages = {062702},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/MGG27V9J/PhysRevA.81.html:text/html;Buhr et al. - 2010 - Energy-sensitive imaging detector applied to the d.pdf:/home/puma/.zotero_bibliography/storage/6UJ52ABP/Buhr et al. - 2010 - Energy-sensitive imaging detector applied to the d.pdf:application/pdf}
}
@article{hahn_storage_2013,
title = {Storage {Ring} {Cross} {Section} {Measurements} for {Electron} {Impact} {Single} and {Double} {Ionization} of {Fe13} + and {Single} {Ionization} of {Fe16} + and {Fe17} +},
volume = {767},
issn = {0004-637X},
url = {http://iopscience.iop.org/0004-637X/767/1/47},
doi = {10.1088/0004-637X/767/1/47},
abstract = {We report measurements of electron impact ionization for Fe13 +, Fe16 +, and Fe17 + over collision energies from below threshold to above 3000 eV. The ions were recirculated using an ion storage ring. Data were collected after a sufficiently long time that essentially all the ions had relaxed radiatively to their ground state. For single ionization of Fe13 +, we find that previous single pass experiments are more than 40\% larger than our results. Compared to our work, the theoretical cross section recommended by Arnaud \& Raymond is more than 30\% larger, while that of Dere is about 20\% greater. Much of the discrepancy with Dere is due to the theory overestimating the contribution of excitation-autoionization via n = 2 excitations. Double ionization of Fe13 + is dominated by direct ionization of an inner shell electron accompanied by autoionization of a second electron. Our results for single ionization of Fe16 + and Fe17 + agree with theoretical calculations to within the experimental uncertainties.},
language = {en},
number = {1},
urldate = {2013-03-26},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Becker, A. and Bernhardt, D. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Spruck, K. and Wolf, A. and Savin, D. W.},
month = apr,
year = {2013},
keywords = {atomic data, atomic processes, methods: laboratory},
pages = {47},
file = {Hahn et al. - 2013 - Storage Ring Cross Section Measurements for Electr.pdf:/home/puma/.zotero_bibliography/storage/UBRC4HDZ/Hahn et al. - 2013 - Storage Ring Cross Section Measurements for Electr.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/U3W48JV3/47.html:text/html}
}
@article{novotny_dissociative_2013,
title = {Dissociative {Recombination} {Measurements} of {HCl}+ {Using} an {Ion} {Storage} {Ring}},
volume = {777},
issn = {0004-637X},
url = {http://iopscience.iop.org/0004-637X/777/1/54},
doi = {10.1088/0004-637X/777/1/54},
abstract = {We have measured dissociative recombination (DR) of HCl+ with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present the measured absolute merged beams recombination rate coefficient for collision energies from 0 to 4.5 eV. We have also developed a new method for deriving the cross section from the measurements. Our approach does not suffer from approximations made by previously used methods. The cross section was transformed to a plasma rate coefficient for the electron temperature range from T = 10 to 5000 K. We show that the previously used HCl+ DR data underestimate the plasma rate coefficient by a factor of 1.5 at T = 10 K and overestimate it by a factor of three at T = 300 K. We also find that the new data may partly explain existing discrepancies between observed abundances of chlorine-bearing molecules and their astrochemical models.},
language = {en},
number = {1},
urldate = {2013-10-17},
journal = {The Astrophysical Journal},
author = {Novotný, O. and Becker, A. and Buhr, H. and Domesle, C. and Geppert, W. and Grieser, M. and Krantz, C. and Kreckel, H. and Repnow, R. and Schwalm, D. and Spruck, K. and Stützel, J. and Yang, B. and Wolf, A. and Savin, D. W.},
month = nov,
year = {2013},
keywords = {ISM: clouds, ISM: molecules, astrochemistry, methods: laboratory: molecular, molecular data, molecular processes},
pages = {54},
file = {Novotný et al. - 2013 - Dissociative Recombination Measurements of HCl+ Us.pdf:/home/puma/.zotero_bibliography/storage/3I34VXS9/Novotný et al. - 2013 - Dissociative Recombination Measurements of HCl+ Us.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/PMUFGRNC/54.html:text/html}
}
@article{herwig_imaging_2013,
title = {Imaging the {Absolute} {Configuration} of a {Chiral} {Epoxide} in the {Gas} {Phase}},
volume = {342},
issn = {0036-8075, 1095-9203},
url = {http://www.sciencemag.org/content/342/6162/1084},
doi = {10.1126/science.1246549},
abstract = {In chemistry and biology, chirality, or handedness, refers to molecules that exist in two spatial configurations that are incongruent mirror images of one another. Almost all biologically active molecules are chiral, and the correct determination of their absolute configuration is essential for the understanding and the development of processes involving chiral molecules. Anomalous x-ray diffraction and vibrational optical activity measurements are broadly used to determine absolute configurations of solid or liquid samples. Determining absolute configurations of chiral molecules in the gas phase is still a formidable challenge. Here we demonstrate the determination of the absolute configuration of isotopically labeled (R,R)-2,3-dideuterooxirane by foil-induced Coulomb explosion imaging of individual molecules. Our technique provides unambiguous and direct access to the absolute configuration of small gas-phase species, including ions and molecular fragments.
Foil-Forged Images
X-ray diffraction is widely used to determine molecular geometries and can often distinguish mirror image isomers (enantiomers), which generally requires well-ordered crystals. Herwig et al. (p. 1084) report an imaging technique to characterize enantiomers in the gas phase. A succession of ionization events were induced by passage through a carbon foil that culminated in a Coulomb explosion of mutually repelling nuclei. The trajectories of these nuclei precisely reflected the original molecular structure.},
language = {en},
number = {6162},
urldate = {2013-11-29},
journal = {Science},
author = {Herwig, Philipp and Zawatzky, Kerstin and Grieser, Manfred and Heber, Oded and Jordon-Thaden, Brandon and Krantz, Claude and Novotný, Oldřich and Repnow, Roland and Schurig, Volker and Schwalm, Dirk and Vager, Zeev and Wolf, Andreas and Trapp, Oliver and Kreckel, Holger},
month = nov,
year = {2013},
pages = {1084--1086},
file = {Herwig et al. - 2013 - Imaging the Absolute Configuration of a Chiral Epo.pdf:/home/puma/.zotero_bibliography/storage/62A4BVWK/Herwig et al. - 2013 - Imaging the Absolute Configuration of a Chiral Epo.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/TER577F5/1084.html:text/html}
}
@article{yang_exploring_2014,
title = {Exploring high-energy doubly excited states of {NH} by dissociative recombination of {NH}+},
volume = {47},
issn = {0953-4075},
url = {http://iopscience.iop.org/0953-4075/47/3/035201},
doi = {10.1088/0953-4075/47/3/035201},
abstract = {We have investigated electron capture by NH+ resulting in dissociative recombination (DR). The impact energies studied of ∼4–12 eV extend over the range below the two lowest predicted NH+ dissociative states in the Franck–Condon (FC) region of the ion. Our focus has been on the final state populations of the resulting N and H atoms. The neutral DR fragments are detected downstream of a merged electron and ion beam interaction zone in the TSR storage ring, which is located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Transverse fragment distances were measured on a recently developed high count-rate imaging detector. The distance distributions enabled a detailed tracking of the final state populations as a function of the electron collision energy. These can be correlated with doubly excited neutral states in the FC region of the ion. At low electron energy of ∼5 eV, the atomic product final levels are nitrogen Rydberg states together with ground-state hydrogen. In a small electron energy interval near 7 eV, a significant part of the final state population forms hydrogen Rydberg atoms with nitrogen atoms in the first excited () term, showing the effect of Rydberg doubly excited states below the predicted 2 2Π ionic potential. The distance distributions above ∼10 eV are compatible with nitrogen Rydberg states correlating to the doubly excited Rydberg state manifold below the ionic 2 4Σ− level.},
language = {en},
number = {3},
urldate = {2014-01-13},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Yang, B. and Novotný, O. and Krantz, C. and Buhr, H. and Mendes, M. and Nordhorn, C. and Geppert, W. D. and Grieser, M. and Repnow, R. and Berg, M. and Bing, D. and Domesle, C. and Grussie, F. and Savin, D. Wolf and Schwalm, D. and Cai, X. and Wolf, A.},
month = feb,
year = {2014},
pages = {035201},
file = {Snapshot:/home/puma/.zotero_bibliography/storage/HAQET9PX/035201.html:text/html;Yang et al. - 2014 - Exploring high-energy doubly excited states of NH .pdf:/home/puma/.zotero_bibliography/storage/4QX6ZIBB/Yang et al. - 2014 - Exploring high-energy doubly excited states of NH .pdf:application/pdf}
}
@article{shornikov_low_2014,
title = {Low cryogen inventory, forced flow {Ne} cooling system with room temperature compression stage and heat recuperation},
volume = {59},
issn = {0011-2275},
url = {http://www.sciencedirect.com/science/article/pii/S0011227513001185},
doi = {10.1016/j.cryogenics.2013.12.001},
abstract = {We present design and commissioning results of a forced flow cooling system utilizing neon at 30 K. The cryogen is pumped through the system by a room-temperature compression stage. To decouple the cold zone from the compression stage a recuperating counterflow tube-in-tube heat exchanger is used. Commissioning demonstrated successful condensation of neon and transfer of up to 30 W cooling power to the load at 30 K using only 30 g of the cryogen circulating in the system at pressures below 170 kPa.},
urldate = {2014-01-20},
journal = {Cryogenics},
author = {Shornikov, A. and Krantz, C. and Wolf, A.},
month = jan,
year = {2014},
keywords = {Cooling system, Forced flow, Neon},
pages = {7--11},
file = {ScienceDirect Snapshot:/home/puma/.zotero_bibliography/storage/JEC3EKXU/S0011227513001185.html:text/html;Shornikov et al. - 2014 - Low cryogen inventory, forced flow Ne cooling syst.pdf:/home/puma/.zotero_bibliography/storage/8FU7EUXX/Shornikov et al. - 2014 - Low cryogen inventory, forced flow Ne cooling syst.pdf:application/pdf}
}
@article{shornikov_maximum_2014,
title = {Maximum intensity, transmission limited cold electron beams from {GaAs} photocathode in the {eV} and sub-{eV} kinetic energy range},
volume = {17},
url = {http://link.aps.org/doi/10.1103/PhysRevSTAB.17.042802},
doi = {10.1103/PhysRevSTAB.17.042802},
abstract = {The deceleration of electrons confined by a weak guiding magnetic field has been studied with the goal of achieving an intense ultracold electron beam, suitable for electron cooling and electron collision experiments with ion beams of very low velocity. By application of a beam deceleration technique the electron current extracted from a GaAs photocathode has been increased by an order of magnitude at a few eV and sub-eV kinetic energy, keeping a low energy spread of the electrons. The true kinetic energy of the slow electrons has been determined, taking space charge effects and contact potential differences into account.},
number = {4},
urldate = {2014-04-01},
journal = {Physical Review Special Topics - Accelerators and Beams},
author = {Shornikov, A. and Orlov, D. A. and Krantz, C. and Jaroshevich, A. S. and Wolf, A.},
month = mar,
year = {2014},
pages = {042802},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/SAS95BZ7/PhysRevSTAB.17.html:text/html;Shornikov et al. - 2014 - Maximum intensity, transmission limited cold elect.pdf:/home/puma/.zotero_bibliography/storage/UCRM5DZD/Shornikov et al. - 2014 - Maximum intensity, transmission limited cold elect.pdf:application/pdf}
}
@article{krantz_absolute_2014,
title = {Absolute rate coefficients for the recombination of open f-shell tungsten ions},
volume = {488},
issn = {1742-6588, 1742-6596},
url = {http://m.iopscience.iop.org/1742-6596/488/1/012051},
doi = {10.1088/1742-6596/488/1/012051},
number = {1},
urldate = {2014-04-15},
journal = {Journal of Physics: Conference Series},
author = {Krantz, C and Spruck, K and Badnell, N R and Becker, A and Bernhardt, D and Grieser, M and Hahn, M and Novotný, O and Repnow, R and Savin, D W and Wolf, A and Müller, A and Schippers, S},
month = apr,
year = {2014},
pages = {012051},
file = {Absolute rate coefficients for the recombination of open f-shell tungsten ions - Abstract - Journal of Physics\: Conference Series - IOPscience:/home/puma/.zotero_bibliography/storage/4B8VDEIF/012051.html:text/html;Krantz et al. - 2014 - Absolute rate coefficients for the recombination o.pdf:/home/puma/.zotero_bibliography/storage/PWEDMS74/Krantz et al. - 2014 - Absolute rate coefficients for the recombination o.pdf:application/pdf}
}
@article{hahn_electron-ion_2014,
title = {Electron-{Ion} {Recombination} of {Fe12} + {Forming} {Fe11} +: {Laboratory} {Measurements} and {Theoretical} {Calculations}},
volume = {788},
issn = {0004-637X},
shorttitle = {Electron-{Ion} {Recombination} of {Fe12} + {Forming} {Fe11} +},
url = {http://iopscience.iop.org/0004-637X/788/1/46},
doi = {10.1088/0004-637X/788/1/46},
abstract = {We have measured dielectronic recombination (DR) for Fe12 + forming Fe11 + using the heavy ion storage ring TSR located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Using our results, we have calculated a plasma rate coefficient from these data that can be used for modeling astrophysical and laboratory plasmas. For the low temperatures characteristic of photoionized plasmas, the experimentally derived rate coefficient is orders of magnitude larger than the previously recommended atomic data. The existing atomic data were also about 40\% smaller than our measurements at temperatures relevant for collisionally ionized plasmas. Recent state-of-the-art theory has difficulty reproducing the detailed energy dependence of the DR spectrum. However, for the Maxwellian plasma rate coefficient, recent theoretical results agree with our measurements to within about 30\% for both photoionized and collisionally ionized plasmas.},
language = {en},
number = {1},
urldate = {2014-06-01},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Badnell, N. R. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = jun,
year = {2014},
keywords = {Instrumentation and Computational Algorithms},
pages = {46},
file = {Hahn et al. - 2014 - Electron-Ion Recombination of Fe12 + Forming Fe11 .pdf:/home/puma/.zotero_bibliography/storage/F2EH4DHN/Hahn et al. - 2014 - Electron-Ion Recombination of Fe12 + Forming Fe11 .pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/46GD3GCA/46.html:text/html}
}
@article{novotny_dissociative_2014,
title = {Dissociative {Recombination} {Measurements} of {NH}+ {Using} an {Ion} {Storage} {Ring}},
volume = {792},
issn = {0004-637X},
url = {http://iopscience.iop.org/0004-637X/792/2/132},
doi = {10.1088/0004-637X/792/2/132},
abstract = {We have investigated dissociative recombination (DR) of NH+ with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present our measured absolute merged-beams recombination rate coefficient for collision energies from 0 to 12 eV. From these data, we have extracted a cross section, which we have transformed to a plasma rate coefficient for the collisional plasma temperature range from T pl = 10 to 18,000 K. We show that the NH+ DR rate coefficient data in current astrochemical models are underestimated by up to a factor of approximately nine. Our new data will result in predicted NH+ abundances lower than those calculated by present models. This is in agreement with the sensitivity limits of all observations attempting to detect NH+ in interstellar clouds.},
language = {en},
number = {2},
urldate = {2014-08-27},
journal = {The Astrophysical Journal},
author = {Novotný, O. and Berg, M. and Bing, D. and Buhr, H. and Geppert, W. and Grieser, M. and Grussie, F. and Krantz, C. and Mendes, M. B. and Nordhorn, C. and Repnow, R. and Schwalm, D. and Yang, B. and Wolf, A. and Savin, D. W.},
month = sep,
year = {2014},
keywords = {The Interstellar Medium},
pages = {132},
file = {Novotný et al. - 2014 - Dissociative Recombination Measurements of NH+ Usi.pdf:/home/puma/.zotero_bibliography/storage/6QSFZFRS/Novotný et al. - 2014 - Dissociative Recombination Measurements of NH+ Usi.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/MGTDASCM/132.html:text/html}
}
@inproceedings{grieser_status_2014,
title = {The {Status} of the {Diagnostic} {System} at the {Cryogenic} {Storage} {Ring} {CSR}},
url = {http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/thpme121.pdf},
urldate = {2014-08-28},
booktitle = {Proceedings of the 6th {International} {Particle} {Accelerator} {Conference}},
author = {Grieser, M. and Becker, A. and Blaum, K. and George, S. and von Hahn, R. and Krantz, C. and Vogel, S. and Wolf, A. and für Kernphysik, M. P. I.},
year = {2014},
pages = {3521--3523},
file = {Grieser et al. - THE STATUS OF THE DIAGNOSTIC SYSTEM AT THE CRYOGEN.pdf:/home/puma/.zotero_bibliography/storage/9AHJ5CZX/Grieser et al. - THE STATUS OF THE DIAGNOSTIC SYSTEM AT THE CRYOGEN.pdf:application/pdf}
}
@article{nordhorn_branching_2011,
title = {Branching ratios in dissociative recombination of formyl and isoformyl cations},
volume = {300},
issn = {1742-6596},
url = {http://iopscience.iop.org/1742-6596/300/1/012004},
doi = {10.1088/1742-6596/300/1/012004},
abstract = {The energy dependence of the branching ratios in dissociative recombination of DCO+ with a known small admixture of DOC+ has been measured for collision energies from 0 to 25eV using an energy- and position-sensitive surface barrier detector which is designed for the analysis of multi-fragment events occurring in a molecular fragmentation study. The measurements are compared with theoretical calculations on the direct mechanism of dissociative recombination of HCO+ including the contribution from HOC+ at the experimental abundance fraction. At low collision energies, dissociative recombination of HCO+ is dominated by dissociation into H + CO. For collision energies above 2eV there is a transition into dissociation to HC+O, which can be explained by electron capture into resonant states. Signatures of DOC+ dissociative recombination are found experimentally and confirmed by the calculations for HOC+. Three-body breakup becomes important for collision energies above 6eV.},
language = {en},
number = {1},
urldate = {2014-11-08},
journal = {Journal of Physics: Conference Series},
author = {Nordhorn, Christian and Bing, Dennis and Buhr, Henrik and Grieser, Manfred and Heber, Oded and Krantz, Claude and Mendes, Mario B. and Repnow, Roland and Schwalm, Dirk and Shornikov, Andrey and Stützel, Julia and Wolf, Andreas and Novotný, Oldřich and Lestinsky, Michael and Larson, Åsa and Stenrup, Michael and Orel, Ann E.},
month = jul,
year = {2011},
pages = {012004},
file = {Nordhorn et al. - 2011 - Branching ratios in dissociative recombination of .pdf:/home/puma/.zotero_bibliography/storage/8WGZJZ7J/Nordhorn et al. - 2011 - Branching ratios in dissociative recombination of .pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/GQJUGUK5/012004.html:text/html}
}
@article{schneider_role_2013,
title = {Role of {Projectile} {Coherence} in {Close} {Heavy} {Ion}-{Atom} {Collisions}},
volume = {110},
url = {http://link.aps.org/doi/10.1103/PhysRevLett.110.113201},
doi = {10.1103/PhysRevLett.110.113201},
abstract = {We have measured fully differential cross sections for single ionization and transfer ionization (TI) in 16 MeV O7++He collisions. The impact parameters mostly contributing to single ionization are about an order of magnitude larger than for TI. Therefore, the projectile beam was much more coherent for the latter compared to the former process. The measured data suggest that, as a result, TI is significantly affected by interference effects which are not present in single ionization.},
number = {11},
urldate = {2014-11-08},
journal = {Physical Review Letters},
author = {Schneider, K. and Schulz, M. and Wang, X. and Kelkar, A. and Grieser, M. and Krantz, C. and Ullrich, J. and Moshammer, R. and Fischer, D.},
month = mar,
year = {2013},
pages = {113201},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/9CBKFRXU/PhysRevLett.110.html:text/html;Schneider et al. - 2013 - Role of Projectile Coherence in Close Heavy Ion-At.pdf:/home/puma/.zotero_bibliography/storage/TSPTJXGH/Schneider et al. - 2013 - Role of Projectile Coherence in Close Heavy Ion-At.pdf:application/pdf}
}
@article{zawatzky_coulomb_2014,
title = {Coulomb {Explosion} {Imaged} {Cryptochiral} ({R},{R})-2,3-{Dideuterooxirane}: {Unambiguous} {Access} to the {Absolute} {Configuration} of (+)-{Glyceraldehyde}},
volume = {20},
copyright = {© 2014 WILEY-VCH Verlag GmbH \& Co. KGaA, Weinheim},
issn = {1521-3765},
shorttitle = {Coulomb {Explosion} {Imaged} {Cryptochiral} ({R},{R})-2,3-{Dideuterooxirane}},
url = {http://onlinelibrary.wiley.com/doi/10.1002/chem.201400296/abstract},
doi = {10.1002/chem.201400296},
abstract = {The absolute configuration of (R,R)-2,3-dideuterooxirane, which has been independently determined using Coulomb explosion imaging, has been unambiguously chemically correlated with the stereochemical key reference (+)-glyceraldehyde. This puts the absolute configuration of D(+)-glyceraldehyde on firm experimental grounds.},
language = {en},
number = {19},
urldate = {2014-11-08},
journal = {Chemistry – A European Journal},
author = {Zawatzky, Kerstin and Herwig, Philipp and Grieser, Manfred and Heber, Oded and Jordon-Thaden, Brandon and Krantz, Claude and Novotný, Oldřich and Repnow, Roland and Schurig, Volker and Schwalm, Dirk and Vager, Zeev and Wolf, Andreas and Kreckel, Holger and Trapp, Oliver},
month = may,
year = {2014},
keywords = {Coulomb explosion imaging, absolute configuration, chirality, deuterium, glyceraldehyde},
pages = {5555--5558},
file = {Snapshot:/home/puma/.zotero_bibliography/storage/C24H7NRE/abstract\;jsessionid=5E212D6232264AFE1F13C0F954358EA2.html:text/html;Zawatzky et al. - 2014 - Coulomb Explosion Imaged Cryptochiral (R,R)-2,3-Di.pdf:/home/puma/.zotero_bibliography/storage/FF8NGCJ7/Zawatzky et al. - 2014 - Coulomb Explosion Imaged Cryptochiral (R,R)-2,3-Di.pdf:application/pdf}
}
@article{novotny_anisotropy_2008,
title = {Anisotropy and {Molecular} {Rotation} in {Resonant} {Low}-{Energy} {Dissociative} {Recombination}},
volume = {100},
url = {http://link.aps.org/doi/10.1103/PhysRevLett.100.193201},
doi = {10.1103/PhysRevLett.100.193201},
abstract = {Angular fragment distributions from the dissociative recombination (DR) of HD+ were measured with well directed monochromatic low-energy electrons over a dense grid of collision energies from 7 to 35 meV, where pronounced rovibrational Feshbach resonances occur. Significant higher-order anisotropies are found in the distributions, whose size varies along energy in a partial correlation with the relative DR rate from fast-rotating molecules. This may indicate a breakdown of the nonrotation assumption so far applied to predict angular DR fragment distributions.},
number = {19},
urldate = {2014-11-08},
journal = {Physical Review Letters},
author = {Novotny, S. and Rubinstein, H. and Buhr, H. and Novotný, O. and Hoffmann, J. and Mendes, M. B. and Orlov, D. A. and Krantz, C. and Berg, M. H. and Froese, M. and Jaroshevich, A. S. and Jordon-Thaden, B. and Lange, M. and Lestinsky, M. and Petrignani, A. and Shafir, D. and Zajfman, D. and Schwalm, D. and Wolf, A.},
month = may,
year = {2008},
pages = {193201},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/EDX2DJTJ/PhysRevLett.100.html:text/html;Novotny et al. - 2008 - Anisotropy and Molecular Rotation in Resonant Low-.pdf:/home/puma/.zotero_bibliography/storage/HAI5QECB/Novotny et al. - 2008 - Anisotropy and Molecular Rotation in Resonant Low-.pdf:application/pdf}
}
@article{trabert_heavy-ion_2012,
title = {Heavy-ion storage-ring-lifetime measurement of metastable levels in the {C}-, {N}-, and {O}-like ions of {Si}, {P}, and {S}},
volume = {85},
url = {http://link.aps.org/doi/10.1103/PhysRevA.85.042508},
doi = {10.1103/PhysRevA.85.042508},
abstract = {In a quest for benchmarking transition rate data on electric-dipole (E1) forbidden transitions to be used in collisional-radiative models of plasma spectra, the radiative decay rates of the metastable levels 2s22p2 1D2, 2s22p3 2Po1/2,3/2, and 2s22p4 1D2 in C-, N-, and O-like ions, respectively, have been measured for the elements Si, P, and S. Results with uncertainties mostly well below 1\% are obtained using ions circulating in a storage ring. Precision results for Si7+, P7+, P8+, P9+, S8+, and S10+ obtained here complete the isoelectronic sequence data sets for these four metastable levels in all three elements.},
number = {4},
urldate = {2014-11-08},
journal = {Physical Review A},
author = {Träbert, E. and Grieser, M. and Hoffmann, J. and Krantz, C. and Repnow, R. and Wolf, A.},
month = apr,
year = {2012},
pages = {042508},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/3VRSF9CU/PhysRevA.85.html:text/html;Träbert et al. - 2012 - Heavy-ion storage-ring-lifetime measurement of met.pdf:/home/puma/.zotero_bibliography/storage/N4XJZAP8/Träbert et al. - 2012 - Heavy-ion storage-ring-lifetime measurement of met.pdf:application/pdf}
}
@article{trabert_m1_2012,
title = {M1 and {E2} decay-dependent lifetime of the lowest {1S0} level in {C}-like ions up to {Ne4}+ measured at a heavy-ion storage ring},
volume = {14},
issn = {1367-2630},
url = {http://iopscience.iop.org/1367-2630/14/2/023061},
doi = {10.1088/1367-2630/14/2/023061},
abstract = {Electric-dipole forbidden transitions within the ground configuration of many ion species play an important role in the diagnostics of terrestrial and astrophysical plasmas, and knowing their rates is essential for collisional-radiative models and spectral simulation. The dominant decay channel of the 2s22p2 1S0 level in the ground configuration of C-like ions changes from electric quadrupole to magnetic dipole within the first few ions of the isoelectronic sequence. Using an electron cyclotron resonance ion source at the TSR heavy-ion storage ring, we realize a lifetime measurement on the system Ne4+ where the magnetic dipole decay channel becomes dominant. These data complement our earlier storage ring lifetime measurements on N+, O2+ and F3+, which we discuss together with the present new result and the available theoretical calculations in their isoelectronic context.},
language = {en},
number = {2},
urldate = {2014-11-08},
journal = {New Journal of Physics},
author = {Träbert, E. and Grieser, M. and Hahn, R. von and Krantz, C. and Repnow, R. and Wolf, A.},
month = feb,
year = {2012},
pages = {023061},
file = {Snapshot:/home/puma/.zotero_bibliography/storage/AS2AQ3CC/023061.html:text/html;Träbert et al. - 2012 - M1 and E2 decay-dependent lifetime of the lowest 1.pdf:/home/puma/.zotero_bibliography/storage/E42UPMIC/Träbert et al. - 2012 - M1 and E2 decay-dependent lifetime of the lowest 1.pdf:application/pdf}
}
@article{hahn_storage_2012,
title = {Storage {Ring} {Cross}-section {Measurements} for {Electron} {Impact} {Single} and {Double} {Ionization} of {Fe9} + and {Single} {Ionization} of {Fe10} +},
volume = {760},
issn = {0004-637X},
url = {http://iopscience.iop.org/0004-637X/760/1/80},
doi = {10.1088/0004-637X/760/1/80},
abstract = {We have measured electron impact ionization from the ground state of Fe9 + and Fe10 + over the relative electron-ion collision energy ranges 200-1900 eV and 250-1800 eV, respectively. The ions were confined in an ion storage ring long enough for essentially all metastable levels to radiatively relax to the ground state. For single ionization, we find a number of discrepancies between the existing theoretical cross sections and our results. The calculations appear to neglect some excitation-autoionization (EA) channels, particularly from n = 3 to n' excitations, which are important near threshold, and those from n = 2 → 3 excitations, which contribute at about 650 eV. Conversely, at higher energies the calculations appear to overestimate the importance of EA channels due to excitation into levels where n ≥ 4. The resulting experimental rate coefficients agree with the most recent theory for Fe9 + to within 16\% and for Fe10 + to within 19\% at temperatures where these ions are predicted to form in collisional ionization equilibrium. We have also measured double ionization of Fe9 + forming Fe11 + in the energy range 450-3000 eV and found that although there is an appreciable cross section for direct double ionization, the dominant mechanism appears to be through direct ionization of an inner shell electron producing an excited state that subsequently stabilizes through autoionization.},
language = {en},
number = {1},
urldate = {2014-11-08},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Becker, A. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Spruck, K. and Wolf, A. and Savin, D. W.},
month = nov,
year = {2012},
keywords = {\&, HII regions, Interstellar medium, molecules},
pages = {80},
file = {Hahn et al. - 2012 - Storage Ring Cross-section Measurements for Electr.pdf:/home/puma/.zotero_bibliography/storage/GSPI8V3U/Hahn et al. - 2012 - Storage Ring Cross-section Measurements for Electr.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/E8UPS72E/80.html:text/html}
}
@article{bernhardt_absolute_2014,
title = {Absolute rate coefficients for photorecombination and electron-impact ionization of magnesiumlike iron ions from measurements at a heavy-ion storage ring},
volume = {90},
url = {http://link.aps.org/doi/10.1103/PhysRevA.90.012702},
doi = {10.1103/PhysRevA.90.012702},
abstract = {Rate coefficients for photorecombination (PR) and cross sections for electron-impact ionization (EII) of Fe14+, forming Fe13+ and Fe15+, respectively, have been measured by employing the electron-ion merged-beams technique at a heavy-ion storage ring. Rate coefficients for PR and EII of Fe14+ ions in a plasma are derived from the experimental measurements. Simple parametrizations of the experimentally derived plasma rate coefficients are provided for use in the modeling of photoionized and collisionally ionized plasmas. In the temperature ranges where Fe14+ is expected to form in such plasmas, the latest theoretical rate coefficients of Altun et al. [Astron. Astrophys. 474, 1051 (2007)] for PR and of Dere [Astron. Astrophys. 466, 771 (2007)] for EII agree with the experimental results to within the experimental uncertainties. Common features in the PR and EII resonance structures are identified and discussed.},
number = {1},
urldate = {2014-11-08},
journal = {Physical Review A},
author = {Bernhardt, D. and Becker, A. and Grieser, M. and Hahn, M. and Krantz, C. and Lestinsky, M. and Novotný, O. and Repnow, R. and Savin, D. W. and Spruck, K. and Wolf, A. and Müller, A. and Schippers, S.},
month = jul,
year = {2014},
pages = {012702},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/PK58IMIM/PhysRevA.90.html:text/html;Bernhardt et al. - 2014 - Absolute rate coefficients for photorecombination .pdf:/home/puma/.zotero_bibliography/storage/5BQNINBX/Bernhardt et al. - 2014 - Absolute rate coefficients for photorecombination .pdf:application/pdf}
}
@article{trabert_m1_2011,
title = {M1, {M2} and hyperfine-induced decay rates in {Mg}-like ions of {Co}, {Ni} and {Cu} measured at a heavy-ion storage ring},
volume = {13},
issn = {1367-2630},
url = {http://iopscience.iop.org/1367-2630/13/2/023017},
doi = {10.1088/1367-2630/13/2/023017},
abstract = {The optical decay rates of the 3s3p 3Po2 level in Mg-like ions of 59Co, 58Ni and 63, 65Cu have been measured at a heavy-ion storage ring. The measurement is sensitive to M1, M2 and hyperfine-induced decay rates. The measurement precision is just about high enough to detect the difference in the isotope effect on the level lifetime in the ions 63, 65Cu17+. We also discuss our findings when trying to measure the hyperfine-induced decay of the lowest triplet level, 3s3p 3Po0, in the two Cu isotopes.},
language = {en},
number = {2},
urldate = {2014-11-08},
journal = {New Journal of Physics},
author = {Träbert, E. and Grieser, M. and Hoffmann, J. and Krantz, C. and Reinhardt, S. and Repnow, R. and Wolf, A. and Indelicato, P.},
month = feb,
year = {2011},
pages = {023017},
file = {Snapshot:/home/puma/.zotero_bibliography/storage/TVAQCRK7/023017.html:text/html;Träbert et al. - 2011 - M1, M2 and hyperfine-induced decay rates in Mg-lik.pdf:/home/puma/.zotero_bibliography/storage/EURIB3MD/Träbert et al. - 2011 - M1, M2 and hyperfine-induced decay rates in Mg-lik.pdf:application/pdf}
}
@article{wang_mutual_2011,
title = {Mutual projectile and target ionization in 1-{MeV}/amu {N4}+ and {N5}++{He} collisions},
volume = {84},
url = {http://link.aps.org/doi/10.1103/PhysRevA.84.022707},
doi = {10.1103/PhysRevA.84.022707},
abstract = {We have studied mutual projectile and target ionization in 1-MeV/amu N4+ and N5++He collisions in kinematically complete experiments by measuring the momenta of the recoil ion and both ejected electrons in coincidence with the charge-changed projectiles. By means of four-particle Dalitz plots, in which multiple differential cross sections are presented as a function of the momenta of all four particles, experimental spectra are compared with theoretical results from various models. The experimental data are qualitatively reproduced by higher-order calculations, where good agreement is achieved for N5++He collisions, while some discrepancies persist for N4++He collisions.},
number = {2},
urldate = {2014-11-08},
journal = {Physical Review A},
author = {Wang, X. and Schneider, K. and Kelkar, A. and Schulz, M. and Najjari, B. and Voitkiv, A. and Gundmundsson, M. and Grieser, M. and Krantz, C. and Lestinsky, M. and Wolf, A. and Hagmann, S. and Moshammer, R. and Ullrich, J. and Fischer, D.},
month = aug,
year = {2011},
pages = {022707},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/QVV83RBX/PhysRevA.84.html:text/html;Wang et al. - 2011 - Mutual projectile and target ionization in 1-MeVa.pdf:/home/puma/.zotero_bibliography/storage/UMS97WEH/Wang et al. - 2011 - Mutual projectile and target ionization in 1-MeVa.pdf:application/pdf}
}
@article{hahn_storage_2011-1,
title = {Storage {Ring} {Cross} {Section} {Measurements} for {Electron} {Impact} {Ionization} of {Fe12} + {Forming} {Fe13} + and {Fe14} +},
volume = {735},
issn = {0004-637X},
url = {http://iopscience.iop.org/0004-637X/735/2/105},
doi = {10.1088/0004-637X/735/2/105},
abstract = {We report electron impact ionization cross section measurements for electron impact single ionization of Fe12 + forming Fe13 + and electron impact double ionization of Fe12 + forming Fe14 +. These are the first electron impact ionization data for any Si-like ion uncontaminated by an unknown metastable fraction. Recent distorted wave calculations agree with our single ionization results to within {\textasciitilde}15\%. Double ionization is dominated by inner shell ionization of a 2l electron resulting in autoionization of a second electron as the inner shell hole is filled.},
language = {en},
number = {2},
urldate = {2014-11-08},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and Schippers, S. and Wolf, A. and Savin, D. W.},
month = jul,
year = {2011},
keywords = {The Interstellar Medium},
pages = {105},
file = {Hahn et al. - 2011 - Storage Ring Cross Section Measurements for Electr.pdf:/home/puma/.zotero_bibliography/storage/QPKN6M8H/Hahn et al. - 2011 - Storage Ring Cross Section Measurements for Electr.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/Z7F78E93/105.html:text/html}
}
@article{herwig_absolute_2014,
title = {Absolute configuration assignment of a chiral molecule in the gas phase using foil-induced {Coulomb} explosion imaging},
volume = {90},
url = {http://link.aps.org/doi/10.1103/PhysRevA.90.052503},
doi = {10.1103/PhysRevA.90.052503},
abstract = {Chiral molecules exist in two configurations that are nonsuperposable mirror images of one another. The underlying molecular structure is referred to as the absolute configuration. In chiral environments, the handedness of molecules influences their chemical characteristics dramatically, and therefore the determination of absolute configurations is of fundamental interest in organic chemistry and biology. Commonly applied techniques to assign absolute configuration are anomalous single-crystal x-ray diffraction and vibrational circular dichroism. However, these techniques become increasingly more challenging when applied to molecules that are made out of light atoms exclusively. Furthermore, there is no established method to determine the absolute handedness of gas-phase molecules that are not optically active. In this work, we apply the foil-induced Coulomb explosion imaging technique to determine directly the absolute configuration of the chiral molecule trans-2,3-dideuterooxirane (C2OD2H2) in the gas phase. The experiment leads to the definitive assignment of the (R,R) configuration to an enantio-selected dideuterooxirane sample with a statistical confidence of 5σ. As the handedness of trans-2,3-dideuterooxirane is unambiguously linked by chemical synthesis to the stereochemical key reference glyceraldehyde, our results provide an independent verification of the absolute configuration of the stereochemical reference standard.},
number = {5},
urldate = {2014-11-28},
journal = {Physical Review A},
author = {Herwig, Philipp and Zawatzky, Kerstin and Schwalm, Dirk and Grieser, Manfred and Heber, Oded and Jordon-Thaden, Brandon and Krantz, Claude and Novotný, Oldřich and Repnow, Roland and Schurig, Volker and Vager, Zeev and Wolf, Andreas and Trapp, Oliver and Kreckel, Holger},
month = nov,
year = {2014},
pages = {052503},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/KE279X3F/PhysRevA.90.html:text/html;Herwig et al. - 2014 - Absolute configuration assignment of a chiral mole.pdf:/home/puma/.zotero_bibliography/storage/576BQEQS/Herwig et al. - 2014 - Absolute configuration assignment of a chiral mole.pdf:application/pdf}
}
@article{wolf_hd_2015,
title = {The {HD} $^{\textrm{+}}$ dissociative recombination rate coefficient at low temperature},
volume = {84},
issn = {2100-014X},
url = {http://www.epj-conferences.org/articles/epjconf/abs/2015/03/epjconf-dr2013_01001/epjconf-dr2013_01001.html},
doi = {10.1051/epjconf/20158401001},
urldate = {2015-02-03},
journal = {EPJ Web of Conferences},
author = {Wolf, A. and Novotný, O. and Buhr, H. and Krantz, C. and Schneider, I.F. and Motapon, O. and Mezei, J.Zs.},
editor = {Schneider, I.F. and Dulieu, O. and Robert, J.},
year = {2015},
pages = {01001},
file = {The HD+ dissociative recombination rate coefficient at low temperature | EPJ Web of Conferences:/home/puma/.zotero_bibliography/storage/P5KAE4E4/epjconf-dr2013_01001.html:text/html;Wolf et al. - 2015 - The HD sup+sup dissociative recombination rat.pdf:/home/puma/.zotero_bibliography/storage/82M9VBS9/Wolf et al. - 2015 - The HD sup+sup dissociative recombination rat.pdf:application/pdf}
}
@article{fedotova_cooling_2013,
title = {Cooling of highly charged ions—the {HITRAP} facility and {Cooler} trap},
volume = {2013},
issn = {1402-4896},
url = {http://iopscience.iop.org/1402-4896/2013/T156/014095},
doi = {10.1088/0031-8949/2013/T156/014095},
abstract = {HITRAP is a facility at GSI in Darmstadt for decelerating, cooling and storing heavy, highly charged ions. It is designed to decelerate a beam of A/q {\textless} 3 particles with an energy of 4 MeV per nucleon as provided by the heavy ion storage ring ESR. HITRAP's decelerating linear accelerator (linac) will decelerate ions down to 6 keV per nucleon and then inject them into a Penning trap for cooling. The trap will capture bunches of up to 105 ions as heavy as U92+ in flight, cool and store them. After extraction from the cooler trap, the vertical beam line (VBL) transports the cold ions to the experiments. The linac has shown to decelerate ions down to 500 keV per nucleon on-line and to 6 keV per nucleon off-line. Recent tests with electrons and ions injected into the trap showed the necessity of a more careful electric and magnetic field alignment. An installed test ion source as well as a system of apertures and position sensitive diagnostics will be used to align the fields. A highly charged ion beam from a small room temperature electron beam ion trap was used for commissioning the VBL.},
language = {en},
number = {T156},
urldate = {2015-03-04},
journal = {Physica Scripta},
author = {Fedotova, S. and Boulton, E. and Brantjes, N. P. M. and Herfurth, F. and Kotovskiy, N. and Krantz, C. and Neidherr, D. and Steinmann, J. and Vorobjev, G. and Collaboration, Hitrap},
month = sep,
year = {2013},
pages = {014095},
file = {Fedotova et al. - 2013 - Cooling of highly charged ions—the HITRAP facility.pdf:/home/puma/.zotero_bibliography/storage/TGKZQIZT/Fedotova et al. - 2013 - Cooling of highly charged ions—the HITRAP facility.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/RVAC6SNV/014095.html:text/html}
}
@article{spruck_efficient_2015,
title = {An efficient, movable single-particle detector for use in cryogenic ultra-high vacuum environments},
volume = {86},
issn = {0034-6748, 1089-7623},
url = {http://scitation.aip.org/content/aip/journal/rsi/86/2/10.1063/1.4907352},
doi = {10.1063/1.4907352},
abstract = {A compact, highly efficient single-particle counting detector for ions of keV/u kinetic energy, movable by a long-stroke mechanical translation stage, has been developed at the Max-Planck-Institut für Kernphysik (Max Planck Institute for Nuclear Physics, MPIK). Both, detector and translation mechanics, can operate at ambient temperatures down to ∼10 K and consist fully of ultra-high vacuum compatible, high-temperature bakeable, and non-magnetic materials. The set-up is designed to meet the technical demands of MPIK’s Cryogenic Storage Ring. We present a series of functional tests that demonstrate full suitability for this application and characterise the set-up with regard to its particle detection efficiency.},
number = {2},
urldate = {2015-02-10},
journal = {Review of Scientific Instruments},
author = {Spruck, Kaija and Becker, Arno and Fellenberger, Florian and Grieser, Manfred and Hahn, Robert von and Klinkhamer, Vincent and Novotný, Oldřich and Schippers, Stefan and Vogel, Stephen and Wolf, Andreas and Krantz, Claude},
month = feb,
year = {2015},
keywords = {storage rings, Cryogenics, SECONDARY EMISSION, Radiation detectors, Particle beam detectors},
pages = {023303},
file = {Snapshot:/home/puma/.zotero_bibliography/storage/NUE25Q7E/1.html:text/html;Spruck et al. - 2015 - An efficient, movable single-particle detector for.pdf:/home/puma/.zotero_bibliography/storage/4IW33PXB/Spruck et al. - 2015 - An efficient, movable single-particle detector for.pdf:application/pdf}
}
@article{schippers_recombination_2011,
title = {Recombination of {Au20}+ at low electron–ion collision energies},
volume = {2011},
issn = {1402-4896},
url = {http://iopscience.iop.org/1402-4896/2011/T144/014039},
doi = {10.1088/0031-8949/2011/T144/014039},
abstract = {The rate coefficient for the recombination of Au20+ with free electrons was measured in the electron–ion collision energy range of 0–10 eV by employing the electron–ion merged-beams technique at the heavy-ion storage ring TSR of the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany. In contrast to earlier measurements with more highly charged Au25+ (Hoffknecht et al 1998 J. Phys. B: At. Mol. Opt. Phys. 31 2415), sharp dielectric recombination resonance features are observed.},
language = {en},
number = {T144},
urldate = {2015-03-24},
journal = {Physica Scripta},
author = {Schippers, S. and Bernhardt, D. and Grieser, M. and Hahn, M. and Krantz, C. and Lestinsky, M. and Novotný, O. and Repnow, R. and Savin, D. W. and Wolf, A. and Müller, A.},
month = jun,
year = {2011},
pages = {014039},
file = {Schippers et al. - 2011 - Recombination of Au20+ at low electron–ion collisi.pdf:/home/puma/.zotero_bibliography/storage/T293CPD5/Schippers et al. - 2011 - Recombination of Au20+ at low electron–ion collisi.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/6MXU3AJS/014039.html:text/html}
}
@article{novotny_cryogenic_2015,
title = {Cryogenic micro-calorimeters for mass spectrometric identification of neutral molecules and molecular fragments},
volume = {118},
issn = {0021-8979, 1089-7550},
url = {http://scitation.aip.org/content/aip/journal/jap/118/10/10.1063/1.4930036},
doi = {10.1063/1.4930036},
abstract = {We have systematically investigated the energy resolution of a magnetic micro-calorimeter (MMC) for atomic and molecular projectiles at impact energies ranging from E ≈ 13 to 150 keV. For atoms we obtained absolute energy resolutions down to Δ E ≈ 120 eV and relative energy resolutions down to Δ E / E ≈ 10 − 3 . We also studied in detail the MMC energy-response function to molecular projectiles of up to mass 56 u. We have demonstrated the capability of identifying neutral fragmentation products of these molecules by calorimetric mass spectrometry. We have modeled the MMC energy-response function for molecular projectiles and concluded that backscattering is the dominant source of the energy spread at the impact energies investigated. We have successfully demonstrated the use of a detector absorber coating to suppress such spreads. We briefly outline the use of MMC detectors in experiments on gas-phase collision reactions with neutral products. Our findings are of general interest for mass spectrometric techniques, particularly for those desiring to make neutral-particle mass measurements.},
number = {10},
urldate = {2015-09-11},
journal = {Journal of Applied Physics},
author = {Novotný, O. and Allgeier, S. and Enss, C. and Fleischmann, A. and Gamer, L. and Hengstler, D. and Kempf, S. and Krantz, C. and Pabinger, A. and Pies, C. and Savin, D. W. and Schwalm, D. and Wolf, A.},
month = sep,
year = {2015},
keywords = {Backscattering, Radiation detectors, Ion beam detectors, Collisional energy loss, Molecular spectra},
pages = {104503},
file = {Novotný et al. - 2015 - Cryogenic micro-calorimeters for mass spectrometri.pdf:/home/puma/.zotero_bibliography/storage/FMKMTWH8/Novotný et al. - 2015 - Cryogenic micro-calorimeters for mass spectrometri.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/3JH9BSR7/1.html:text/html}
}
@article{hahn_storage_2015,
title = {Storage {Ring} {Cross} {Section} {Measurements} for {Electron} {Impact} {Ionization} of {Fe7}+},
volume = {813},
issn = {0004-637X},
url = {http://stacks.iop.org/0004-637X/813/i=1/a=16},
doi = {10.1088/0004-637X/813/1/16},
abstract = {We have measured electron impact ionization for Fe 7+ from the ionization threshold up to 1200 eV. The measurements were performed using the TSR heavy ion storage ring. The ions were stored long enough prior to measurements to remove most metastables, resulting in a beam of 94\% ground-level ions. Comparing with the previously recommended atomic data, we find that the Arnaud \& Raymond cross section is up to about 40\% larger than our measurement, with the largest discrepancies below about 400 eV. The cross section of Dere agrees to within 10\%, which is about the magnitude of the experimental uncertainties. The remaining discrepancies between our measurement and the Dere calculations are likely due to shortcomings in the theoretical treatment of the excitation-autoionization contribution.},
language = {en},
number = {1},
urldate = {2015-10-23},
journal = {The Astrophysical Journal},
author = {Hahn, M. and Becker, A. and Bernhardt, D. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Repnow, R. and {S. Schippers} and Spruck, K. and Wolf, A. and Savin, D. W.},
year = {2015},
pages = {16},
file = {Hahn et al. - 2015 - Storage Ring Cross Section Measurements for Electr.pdf:/home/puma/.zotero_bibliography/storage/22U68IMR/Hahn et al. - 2015 - Storage Ring Cross Section Measurements for Electr.pdf:application/pdf}
}
@article{herfurth_hitrap_2012,
title = {{HITRAP} – {Heavy}, highly charged {Ions} at {Rest}: {Status} and experimental {Opportunities}},
volume = {388},
issn = {1742-6596},
shorttitle = {{HITRAP} – {Heavy}, highly charged {Ions} at {Rest}},
url = {http://stacks.iop.org/1742-6596/388/i=14/a=142009},
doi = {10.1088/1742-6596/388/14/142009},
abstract = {HITRAP, the facility for heavy, highly-charged ions at rest, is being commissioned at GSI in Darmstadt. The highly-charged ions are produced by stripping all electrons at 400 MeV/u and then decelerating the beam of bare, heavy nuclei in a storage ring, the ESR, and a linear decelerator. The first steps have been taken into operation successfully; about 10 5 ions have been decelerated to 0.5 MeV/u. The remaining deceleration and cooling in a RFQ decelerator structure and a Penning trap is prepared. For off-line tests of the experiments as well as the cooler Penning trap, a compact room-temperature EBIT has been installed and delivers beam already.},
language = {en},
number = {14},
urldate = {2016-03-16},
journal = {Journal of Physics: Conference Series},
author = {Herfurth, F. and Barth, W. and Clemente, G. and Dahl, L. A. and Gerhard, P. and Kaiser, M. and Kester, O. K. and Kluge, H.-J. and Krantz, C. and {N Kotovskiy} and Kozhuharov, C. and Maier, M. and Pfister, J. and Quint, W. and Ratzinger, U. and Schempp, A. and Sokolov, A. and Stöhlker, Th and {H Vormann} and Vorobjev, G. and Wolf, A. and Yaramishev, S. and collaboration, the Hitrap},
year = {2012},
pages = {142009},
file = {Herfurth et al. - 2012 - HITRAP – Heavy, highly charged Ions at Rest Statu.pdf:/home/puma/.zotero_bibliography/storage/XDV7SCHR/Herfurth et al. - 2012 - HITRAP – Heavy, highly charged Ions at Rest Statu.pdf:application/pdf}
}
@article{bernhardt_absolute_2016,
title = {Absolute rate coefficients for photorecombination of beryllium-like and boron-like silicon ions},
volume = {49},
issn = {0953-4075},
url = {http://stacks.iop.org/0953-4075/49/i=7/a=074004},
doi = {10.1088/0953-4075/49/7/074004},
abstract = {We report measured rate coefficients for electron–ion recombination of Si 10+ forming Si 9+ and of Si 9+ forming Si 8+ , respectively. The measurements were performed using the electron–ion merged-beams technique at a heavy-ion storage ring. Electron–ion collision energies ranged from 0 to 50 eV for Si 9+ and from 0 to 2000 eV for Si 10+ , thus, extending previous measurements for Si 10+ (Orban et al 2010 Astrophys. J. 721 [http://dx.doi.org/10.1088/0004-637x/721/2/1603] 1603 ) to much higher energies. Experimentally derived rate coefficients for the recombination of Si 9+ and Si 10+ ions in a plasma are presented along with simple parameterizations. These rate coefficients are useful for the modeling of the charge balance of silicon in photoionized plasmas (Si 9+ and Si 10+ ) and in collisionally ionized plasmas (Si 10+ only). In the corresponding temperature ranges, the experimentally derived rate coefficients agree with the latest corresponding theoretical results within the experimental uncertainties.},
language = {en},
number = {7},
urldate = {2016-03-17},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Bernhardt, D. and Becker, A. and Brandau, C. and Grieser, M. and Hahn, M. and Krantz, C. and Lestinsky, M. and Novotný, O. and Repnow, R. and Savin, D. W. and {K Spruck} and Wolf, A. and Müller, A. and Schippers, S.},
year = {2016},
pages = {074004},
file = {Bernhardt et al. - 2016 - Absolute rate coefficients for photorecombination .pdf:/home/puma/.zotero_bibliography/storage/7IBGEXSE/Bernhardt et al. - 2016 - Absolute rate coefficients for photorecombination .pdf:application/pdf}
}
@article{oconnor_photodissociation_2016,
title = {Photodissociation of an {Internally} {Cold} {Beam} of {CH}+ {Ions} in a {Cryogenic} {Storage} {Ring}},
volume = {116},
url = {http://link.aps.org/doi/10.1103/PhysRevLett.116.113002},
doi = {10.1103/PhysRevLett.116.113002},
abstract = {We have studied the photodissociation of CH+ in the Cryogenic Storage Ring at ambient temperatures below 10 K. Owing to the extremely high vacuum of the cryogenic environment, we were able to store CH+ beams with a kinetic energy of ∼60 keV for several minutes. Using a pulsed laser, we observed Feshbach-type near-threshold photodissociation resonances for the rotational levels J=0–2 of CH+, exclusively. In comparison to updated, state-of-the-art calculations, we find excellent agreement in the relative intensities of the resonances for a given J, and we can extract time-dependent level populations. Thus, we can monitor the spontaneous relaxation of CH+ to its lowest rotational states and demonstrate the preparation of an internally cold beam of molecular ions.},
number = {11},
urldate = {2016-03-24},
journal = {Physical Review Letters},
author = {O’Connor, A. P. and Becker, A. and Blaum, K. and Breitenfeldt, C. and George, S. and Göck, J. and Grieser, M. and Grussie, F. and Guerin, E. A. and von Hahn, R. and Hechtfischer, U. and Herwig, P. and Karthein, J. and Krantz, C. and Kreckel, H. and Lohmann, S. and Meyer, C. and Mishra, P. M. and Novotný, O. and Repnow, R. and Saurabh, S. and Schwalm, D. and Spruck, K. and Sunil Kumar, S. and Vogel, S. and Wolf, A.},
year = {2016},
pages = {113002},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/2QVS6EER/PhysRevLett.116.html:text/html;O’Connor et al. - 2016 - Photodissociation of an Internally Cold Beam of CH.pdf:/home/puma/.zotero_bibliography/storage/293ND9DB/O’Connor et al. - 2016 - Photodissociation of an Internally Cold Beam of CH.pdf:application/pdf}
}
@article{hahn_storage_2016,
title = {Storage ring cross section measurements for electron impact ionization of {Fe} 8+},
volume = {49},
issn = {0953-4075},
url = {http://stacks.iop.org/0953-4075/49/i=8/a=084006},
doi = {10.1088/0953-4075/49/8/084006},
abstract = {We have measured electron impact ionization (EII) for Fe 8+ forming Fe 9+ from below the ionization threshold to 1200 eV. These measurements were carried out at the TSR heavy ion storage ring. The objective of using a storage ring is to store the ion beam initially so that metastable levels decay, thereby allowing for measurements on a well-defined ground-level ion beam. In this case, however, some metastable levels were too long lived to be removed. We discuss several methods for quantifying the metastable fraction, which we estimate to be ∼30\%–40\%. Although metastables remain problematic, the present storage ring work improves upon other experimental geometries by limiting the metastable contamination to only a few long-lived excited levels. We discuss some future prospects for obtaining improved measurements of Fe 8+ and other ions with long-lived metastable levels.},
language = {en},
number = {8},
urldate = {2016-04-17},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Hahn, M. and Becker, A. and Bernhardt, D. and Grieser, M. and Krantz, C. and Lestinsky, M. and Müller, A. and Novotný, O. and Pindzola, M. S. and {R Repnow} and Schippers, S. and Spruck, K. and Wolf, A. and Savin, D. W.},
year = {2016},
pages = {084006},
file = {Hahn et al. - 2016 - Storage ring cross section measurements for electr.pdf:/home/puma/.zotero_bibliography/storage/M6J8BB75/Hahn et al. - 2016 - Storage ring cross section measurements for electr.pdf:application/pdf}
}
@article{von_hahn_cryogenic_2016,
title = {The {Cryogenic} {Storage} {Ring} {CSR}},
volume = {87},
issn = {0034-6748, 1089-7623},
url = {http://scitation.aip.org/content/aip/journal/rsi/87/6/10.1063/1.4953888},
doi = {10.1063/1.4953888},
abstract = {An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm−3 is derived, equivalent to a room-temperature pressure below 10−14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.},
number = {6},
urldate = {2016-06-17},
journal = {Review of Scientific Instruments},
author = {von Hahn, R. and Becker, A. and Berg, F. and Blaum, K. and Breitenfeldt, C. and Fadil, H. and Fellenberger, F. and Froese, M. and George, S. and Göck, J. and Grieser, M. and Grussie, F. and Guerin, E. A. and Heber, O. and Herwig, P. and Karthein, J. and Krantz, C. and Kreckel, H. and Lange, M. and Laux, F. and Lohmann, S. and Menk, S. and Meyer, C. and Mishra, P. M. and Novotný, O. and O’Connor, A. P. and Orlov, D. A. and Rappaport, M. L. and Repnow, R. and Saurabh, S. and Schippers, S. and Schröter, C. D. and Schwalm, D. and Schweikhard, L. and Sieber, T. and Shornikov, A. and Spruck, K. and Kumar, S. Sunil and Ullrich, J. and Urbain, X. and Vogel, S. and Wilhelm, P. and Wolf, A. and Zajfman, D.},
month = jun,
year = {2016},
keywords = {ion beams, storage rings, Electrostatics, Electrodes, Quadrupoles},
pages = {063115},
file = {Hahn et al. - 2016 - The cryogenic storage ring CSR.pdf:/home/puma/.zotero_bibliography/storage/ZEFSZM3B/Hahn et al. - 2016 - The cryogenic storage ring CSR.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/CGQ5UTTX/1.html:text/html}
}
@inproceedings{scheeler_recommissioning_2016,
title = {Recommissioning of the {Marburg} {Ion}-beam {Therapy} {Centre} ({MIT}) {Accelerator} {Facility}},
url = {http://jacow.org/ipac2016/papers/tupoy004.pdf},
doi = {doi:10.18429/JACoW-IPAC2016-TUPOY004},
urldate = {2016-06-17},
booktitle = {Proceedings of the 7th {International} {Particle} {Accelerator} {Conference} ({IPAC}'16), {Busan}, {Korea}, {May} 8-13, 2016},
publisher = {JACOW, Geneva, Switzerland},
author = {Scheeler, Uwe and Krantz, Claude and Sievers, Sven and Strohmeier, Markus and Cee, Rainer and Feldmeier, Eike and Galonska, Michael and Höppner, Klaus and Mosthaf, Jörg and Scheloske, Stefan and Winkelmann, Tim and Schömers, Christian and Peters, Andreas and Haberer, Thomas},
year = {2016},
pages = {1908--1910},
file = {Scheeler et al. - 2016 - Recommissioning of the Marburg Ion-beam Therapy Ce.pdf:/home/puma/.zotero_bibliography/storage/5JAHAS8P/Scheeler et al. - 2016 - Recommissioning of the Marburg Ion-beam Therapy Ce.pdf:application/pdf}
}
@article{badnell_recombination_2016,
title = {Recombination of {W19}+ ions with electrons: {Absolute} rate coefficients from a storage-ring experiment and from theoretical calculations},
volume = {93},
shorttitle = {Recombination of \$\{{\textbackslash}mathrm\{{W}\}\}{\textasciicircum}\{19+\}\$ ions with electrons},
url = {http://link.aps.org/doi/10.1103/PhysRevA.93.052703},
doi = {10.1103/PhysRevA.93.052703},
abstract = {Experimentally measured and theoretically calculated rate coefficients for the recombination of W19+([Kr]4d104f9) ions with free electrons (forming W18+) are presented. At low electron-ion collision energies, the merged-beam rate coefficient is dominated by strong, mutually overlapping, recombination resonances as already found previously for the neighboring charge-state ions W18+ and W20+. In the temperature range where W19+ is expected to form in a collisionally ionized plasma, the experimentally derived recombination rate coefficient deviates by up to a factor of about 20 from the theoretical rate coefficient obtained from the Atomic Data and Analysis Structure database. The present calculations, which employ a Breit–Wigner redistributive partitioning of autoionizing widths for dielectronic recombination via multi-electron resonances, reproduce the experimental findings over the entire temperature range.},
number = {5},
urldate = {2016-07-28},
journal = {Physical Review A},
author = {Badnell, N. R. and Spruck, K. and Krantz, C. and Novotný, O. and Becker, A. and Bernhardt, D. and Grieser, M. and Hahn, M. and Repnow, R. and Savin, D. W. and Wolf, A. and Müller, A. and Schippers, S.},
month = may,
year = {2016},
pages = {052703},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/S2Q7UF8V/PhysRevA.93.html:text/html;Badnell et al. - 2016 - Recombination of W19+ ions with electrons Absolut.pdf:/home/puma/.zotero_bibliography/storage/2IHJJARW/Badnell et al. - 2016 - Recombination of W19+ ions with electrons Absolut.pdf:application/pdf}
}
@article{gamer_mocca:_2016,
title = {{MOCCA}: {A} 4k-{Pixel} {Molecule} {Camera} for the {Position}- and {Energy}-{Resolving} {Detection} of {Neutral} {Molecule} {Fragments} at {CSR}},
volume = {184},
issn = {0022-2291, 1573-7357},
shorttitle = {{MOCCA}},
url = {http://link.springer.com/10.1007/s10909-015-1453-0},
doi = {10.1007/s10909-015-1453-0},
language = {en},
number = {3-4},
urldate = {2016-08-31},
journal = {Journal of Low Temperature Physics},
author = {Gamer, L. and Schulz, D. and Enss, C. and Fleischmann, A. and Gastaldo, L. and Kempf, S. and Krantz, C. and Novotný, O. and Schwalm, D. and Wolf, A.},
month = aug,
year = {2016},
pages = {839--844},
file = {Gamer et al. - 2016 - MOCCA A 4k-Pixel Molecule Camera for the Position.pdf:/home/puma/.zotero_bibliography/storage/DWE6DI3Z/Gamer et al. - 2016 - MOCCA A 4k-Pixel Molecule Camera for the Position.pdf:application/pdf}
}
@article{krantz_single-particle_2017,
title = {Single-particle detection of products from atomic and molecular reactions in a cryogenic ion storage ring},
volume = {851},
issn = {0168-9002},
url = {https://www.sciencedirect.com/science/article/pii/S0168900217301134},
doi = {10.1016/j.nima.2017.01.050},
abstract = {We have used a single-particle detector system, based on secondary electron emission, for counting low-energetic (∼keV/u) massive products originating from atomic and molecular ion reactions in the electrostatic Cryogenic Storage Ring (CSR). The detector is movable within the cryogenic vacuum chamber of CSR, and was used to measure production rates of a variety of charged and neutral daughter particles. In operation at a temperature of ∼ 6 K , the detector is characterised by a high dynamic range, combining a low dark event rate with good high-rate particle counting capability. On-line measurement of the pulse height distributions proved to be an important monitor of the detector response at low temperature. Statistical pulse-height analysis allows to infer the particle detection efficiency of the detector, which has been found to be close to unity also in cryogenic operation at 6 K.},
urldate = {2017-02-07},
journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
author = {Krantz, C. and Novotný, O. and Becker, A. and George, S. and Grieser, M. and Hahn, R. von and Meyer, C. and Schippers, S. and Spruck, K. and Vogel, S. and Wolf, A.},
month = apr,
year = {2017},
keywords = {Storage ring, Low temperature, Secondary electrons, Single-ion detection},
pages = {92--102},
file = {Krantz et al. - 2017 - Single-particle detection of products from atomic .pdf:/home/puma/.zotero_bibliography/storage/D65A6XI8/Krantz et al. - 2017 - Single-particle detection of products from atomic .pdf:application/pdf;ScienceDirect Snapshot:/home/puma/.zotero_bibliography/storage/ADZMXXVS/S0168900217301134.html:text/html}
}
@article{krantz_recombination_2017,
title = {Recombination of open-f-shell tungsten ions},
volume = {50},
issn = {0953-4075},
url = {http://stacks.iop.org/0953-4075/50/i=5/a=052001},
doi = {10.1088/1361-6455/aa547d},
abstract = {We review experimental and theoretical efforts aimed at a detailed understanding of the recombination of electrons with highly charged tungsten ions characterised by an open 4 f sub-shell. Highly charged tungsten occurs as a plasma contaminant in ITER-like tokamak experiments, where it acts as an unwanted cooling agent. Modelling of the charge state populations in a plasma requires reliable thermal rate coefficients for charge-changing electron collisions. The electron recombination of medium-charged tungsten species with open 4 f sub-shells is especially challenging to compute reliably. Storage-ring experiments have been conducted that yielded recombination rate coefficients at high energy resolution and well-understood systematics. Significant deviations compared to simplified, but prevalent, computational models have been found. A new class of ab initio numerical calculations has been developed that provides reliable predictions of the total plasma recombination rate coefficients for these ions.},
language = {en},
number = {5},
urldate = {2017-02-11},
journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
author = {Krantz, C. and Badnell, N. R. and Müller, A. and Schippers, S. and Wolf, A.},
year = {2017},
pages = {052001},
file = {Krantz et al. - 2017 - Recombination of open- f -shell tungsten ions.pdf:/home/puma/.zotero_bibliography/storage/IMPNHEV4/Krantz et al. - 2017 - Recombination of open- f -shell tungsten ions.pdf:application/pdf}
}
@inproceedings{orlov_ultra_2009,
title = {Ultra {Cold} {Photoelectron} {Beams} for {Ion} {Storage} {Rings}},
url = {http://aip.scitation.org/doi/abs/10.1063/1.3215583},
doi = {10.1063/1.3215583},
language = {en},
urldate = {2017-05-02},
publisher = {AIP},
author = {Orlov, D. A. and Krantz, C. and Shornikov, A. and Lestinsky, M. and Hoffmann, J. and Jaroshevich, A. S. and Kosolobov, S. N. and Terekhov, A. S. and Wolf, A.},
year = {2009},
pages = {1007--1016},
file = {Orlov et al. - 2009 - Ultra Cold Photoelectron Beams for Ion Storage Rin.pdf:/home/puma/.zotero_bibliography/storage/85VNKSJV/Orlov et al. - 2009 - Ultra Cold Photoelectron Beams for Ion Storage Rin.pdf:application/pdf}
}
@article{meyer_radiative_2017,
title = {Radiative {Rotational} {Lifetimes} and {State}-{Resolved} {Relative} {Detachment} {Cross} {Sections} from {Photodetachment} {Thermometry} of {Molecular} {Anions} in a {Cryogenic} {Storage} {Ring}},
volume = {119},
issn = {0031-9007, 1079-7114},
url = {http://link.aps.org/doi/10.1103/PhysRevLett.119.023202},
doi = {10.1103/PhysRevLett.119.023202},
language = {en},
number = {2},
urldate = {2017-07-20},
journal = {Physical Review Letters},
author = {Meyer, C. and Becker, A. and Blaum, K. and Breitenfeldt, C. and George, S. and Göck, J. and Grieser, M. and Grussie, F. and Guerin, E. A. and von Hahn, R. and Herwig, P. and Krantz, C. and Kreckel, H. and Lion, J. and Lohmann, S. and Mishra, P. M. and Novotný, O. and O’Connor, A. P. and Repnow, R. and Saurabh, S. and Schwalm, D. and Schweikhard, L. and Spruck, K. and Sunil Kumar, S. and Vogel, S. and Wolf, A.},
month = jul,
year = {2017},
pages = {023202},
file = {Meyer et al. - 2017 - Radiative Rotational Lifetimes and State-Resolved .pdf:/home/puma/.zotero_bibliography/storage/VJT2VVXC/Meyer et al. - 2017 - Radiative Rotational Lifetimes and State-Resolved .pdf:application/pdf}
}
@article{novotny_dissociative_2018,
title = {Dissociative {Recombination} {Measurements} of {Chloronium} {Ions} ({D2Cl}+) {Using} an {Ion} {Storage} {Ring}},
volume = {862},
issn = {0004-637X},
url = {http://stacks.iop.org/0004-637X/862/i=2/a=166},
doi = {10.3847/1538-4357/aacefc},
abstract = {We report our plasma rate coefficient and branching ratio measurements for dissociative recombination (DR) of \#\#IMG\#\# [http://ej.iop.org/images/0004-637X/862/2/166/apjaacefcieqn1.gif] \${\textbackslash}rmD\_2{\textbackslash}mathrmCl{\textasciicircum}+\$ with electrons. The studies were performed in a merged-beams configuration using the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Starting with our absolute merged-beams recombination rate coefficient at a collision energy of ≈0 eV, we have extracted the cross section and produced a plasma rate coefficient for a translational temperature of ≈8 K. Furthermore, extrapolating our cross-section results using the typical low-energy DR behavior, we have generated a plasma rate coefficient for translational temperatures from 5 to 500 K. We find good agreement between our extrapolated results and previous experimental DR studies on \#\#IMG\#\# [http://ej.iop.org/images/0004-637X/862/2/166/apjaacefcieqn2.gif] \${\textbackslash}rmD\_2{\textbackslash}mathrmCl{\textasciicircum}+\$ . Additionally, we have investigated the three fragmentation channels for DR of \#\#IMG\#\# [http://ej.iop.org/images/0004-637X/862/2/166/apjaacefcieqn3.gif] \${\textbackslash}rmD\_2{\textbackslash}mathrmCl{\textasciicircum}+\$ . Here we report on the dissociation geometry of the three-body fragmentation channel, the kinetic energy released for each of the three outgoing channels, the molecular internal excitation for the two outgoing channels that produce molecular fragments, and the fragmentation branching ratios for all three channels. Our results, in combination with those of other groups, indicate that any remaining uncertainties in the DR rate coefficient for \#\#IMG\#\# [http://ej.iop.org/images/0004-637X/862/2/166/apjaacefcieqn4.gif] \${\textbackslash}rmH\_2{\textbackslash}mathrmCl{\textasciicircum}+\$ appear unlikely to explain the observed discrepancies between the inferred abundances of HCl and \#\#IMG\#\# [http://ej.iop.org/images/0004-637X/862/2/166/apjaacefcieqn5.gif] \${\textbackslash}rmH\_2{\textbackslash}mathrmCl{\textasciicircum}+\$ in molecular clouds and predictions from astrochemical models.},
language = {en},
number = {2},
urldate = {2018-08-06},
journal = {The Astrophysical Journal},
author = {Novotný, O. and Buhr, H. and Geppert, W. and Grieser, M. and Hamberg, M. and Krantz, C. and Mendes, M. B. and Petrignani, A. and {R. Repnow} and Savin, D. W. and Schwalm, D. and Stützel, J. and Wolf, A.},
year = {2018},
pages = {166},
file = {Novotný et al. - 2018 - Dissociative Recombination Measurements of Chloron.pdf:/home/puma/.zotero_bibliography/storage/DIZU6KAF/Novotný et al. - 2018 - Dissociative Recombination Measurements of Chloron.pdf:application/pdf}
}
@article{krantz_slow_2018,
title = {Slow {Extraction} {Techniques} at the {Marburg} {Ion}-{Beam} {Therapy} {Centre}},
url = {http://jacow.org/ipac2018/doi/JACoW-IPAC2018-TUPAL036.html},
doi = {10.18429/jacow-ipac2018-tupal036},
abstract = {The Marburg Ion-Beam Therapy Centre offers hadron therapy using proton and carbon beams. The accelerator is based on a 65-m ion synchrotron by Danfysik/Siemens Healthcare. Beam extraction from the synchrotron is driven by a transverse RF knock-out (KO) system featuring Dynamic Intensity Control (DIC) of the spill. DIC allows modulation of the extraction rate by factors up to 30 on millisecond time scales. A fast response of the system to the variable intensity set-point can be obtained by careful adjustment of the RF-KO spectrum relative to the machine tune. Tracking simulations of the extraction phase have been conducted to refine that behaviour. Presently, we investigate how fast machine tune shifts, induced by an air-core quadrupole lens, can be used as a way to further improve the spill quality.},
language = {en},
urldate = {2018-08-06},
journal = {Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada},
author = {Krantz, Claude and Cee, Rainer and Faber, Fiona and Feldmeier, Eike and Fischer, Tobias and Galonska, Michael and Haberer, Thomas and Kroeck, Benno and Peters, Andreas and Scheeler, Uwe and Scheloske, Stefan and Schömers, Christian and Weber, Adrian and Witt, Matthias},
editor = {{Satogata, Todd (Ed.)} and {Schaa, Volker RW (Ed.)}},
year = {2018},
pages = {1084--1086},
file = {Krantz et al. - 2018 - Slow Extraction Techniques at the Marburg Ion-Beam.pdf:/home/puma/.zotero_bibliography/storage/62FQXEPE/Krantz et al. - 2018 - Slow Extraction Techniques at the Marburg Ion-Beam.pdf:application/pdf}
}
@article{krantz_ultra_2009,
title = {An ultra cold photoelectron gun for the {Heidelberg} {TSR} target section},
volume = {192},
issn = {1742-6596},
url = {http://stacks.iop.org/1742-6596/192/i=1/a=012025},
doi = {10.1088/1742-6596/192/1/012025},
abstract = {We present a cryogenic photoelectron gun, developed for the target section of the Test Storage Ring (TSR) of the Max Planck Institute of Nuclear Physics (MPIK). Cooled to cryogenic temperatures by liquid nitrogen, the photocathode source provides an electron gas with an initial thermal energy spread of around 10 meV. The beam optics of the target section reduce the electron temperatures to much lower values in the comoving frame of the beam. Recently the photocathode source has seen significant improvements regarding its reliability. By controlling several cathode degradation mechanisms, including cryosorption, vacuum degrading leak electron currents, and backstream of ionised restgas particles, cathode lifetime and currents have been subject to substantial improvements. Presently the photoelectron gun can deliver currents of up to 1 mA at lifetimes of about 24h. The ability of the photoelectron beam to cool slow, heavy molecular ion beams was demonstrated by cooling a 3 MeV CF + beam in the TSR. At an electron cooling energy of only 53 eV and a perveance-limited current of 0.34 mA, a cooling time below 2 s has been achieved, with a very small transverse relative momentum spread of 2.5 · 10 −5 and final ion beam cross-section of 0.5×0.1 mm 2 .},
language = {en},
number = {1},
urldate = {2018-08-06},
journal = {Journal of Physics: Conference Series},
author = {Krantz, C. and Orlov, D. A. and Hoffmann, J. and Lestinsky, M. and Novotny, O. and Jaroshevich, A. S. and Terekhov, A. S. and Wolf, A.},
year = {2009},
pages = {012025},
file = {Krantz et al. - 2009 - An ultra cold photoelectron gun for the Heidelberg.pdf:/home/puma/.zotero_bibliography/storage/MMIDMIC6/Krantz et al. - 2009 - An ultra cold photoelectron gun for the Heidelberg.pdf:application/pdf}
}
@article{novotny_dissociative_2009,
title = {Dissociative recombination of {CF}\${\textbackslash}mathplus\$: {Experiment} and theory},
volume = {192},
issn = {1742-6596},
shorttitle = {Dissociative recombination of {CF}\${\textbackslash}mathplus\$},
url = {https://doi.org/10.1088%2F1742-6596%2F192%2F1%2F012021},
doi = {10.1088/1742-6596/192/1/012021},
abstract = {We present results from our recent studies of the dissociative recombination of the CF+ cation. On one hand, dissociative recombination was measured with 3 MeV CF+ ions in the heavy-ion Test Storage Ring in Heidelberg, using the twin electron beam configuration with an electron cooler and a separated electron target for collision measurements. In this experiment, the low temperatures of the electron beam provided by a photocathode (temperature in co-moving frame below 1 meV) account for a fast kinetic cooling of the heavy-ion beam and a high resolution in the measured rate coefficients. Fragment imaging measurements show a complete switching of the dissociation route by only a small change of the collision energy and the disappearance of neutral Rydberg product states on crossing the DE threshold. On the other hand, extensive calculations of energy positions and autoionization widths for the doubly excited states of CF between the first and second ionization thresholds have been obtained from electron scattering calculations using the complex Kohn variational method, followed by calculations of the dissociative recombination process with the multichannel quantum defect theory. In preliminary computations, only the first dissociative state in each molecular symmetry, which lies closest in energy to the ion potential at its equilibrium internuclear separation, and thus is dominant for the low-energy dissociative recombination, was included. Although only the direct mechanism of dissociative recombination reaction has been considered in this step, the size and the shape of the DR rate coefficient are already well reproduced.},
language = {en},
urldate = {2019-04-30},
journal = {Journal of Physics: Conference Series},
author = {Novotný, O. and Motapon, O. and Berg, M. H. and Bing, D. and Buhr, H. and Fadil, H. and Grieser, M. and Hoffmann, J. and Jaroshevich, A. S. and Jordon-Thaden, B. and Krantz, C. and Lange, M. and Lestinsky, M. and Mendes, M. and Novotny, S. and Orlov, D. A. and Petrignani, A. and Schneider, I. F. and Orel, A. E. and Wolf, A.},
month = oct,
year = {2009},
pages = {012021},
file = {Novotný et al. - 2009 - Dissociative recombination of CF\$mathplus\$ Exper.pdf:/home/puma/.zotero_bibliography/storage/9N3YSJPX/Novotný et al. - 2009 - Dissociative recombination of CF\$mathplus\$ Exper.pdf:application/pdf}
}
@article{novotny_quantum-stateselective_2019,
title = {Quantum-state–selective electron recombination studies suggest enhanced abundance of primordial {HeH}+},
volume = {365},
copyright = {Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. http://www.sciencemag.org/about/science-licenses-journal-article-reuseThis is an article distributed under the terms of the Science Journals Default License.},
issn = {0036-8075, 1095-9203},
url = {https://science.sciencemag.org/content/365/6454/676},
doi = {10.1126/science.aax5921},
abstract = {Enhanced abundance of primordial HeH+
Though only recently detected in space, the helium hydride ion (HeH+) is thought to be the first molecule ever to have formed in the early Universe. Novotný et al. report state-specific rate coefficients for the dissociative reaction of HeH+ with electrons, obtained using a cryogenic ion storage ring combined with a merged electron beam (see the Perspective by Bovino and Galli). They detect substantial rotational dependence and a decrease of the rates for the lowest states of HeH+, far below the values listed in astrochemistry databases and those previously applied in early-Universe models. These results suggest high abundance of this important primordial molecule at redshifts of first star and galaxy formation.
Science, this issue p. 676; see also p. 639
The epoch of first star formation in the early Universe was dominated by simple atomic and molecular species consisting mainly of two elements: hydrogen and helium. Gaining insight into this constitutive era requires a thorough understanding of molecular reactivity under primordial conditions. We used a cryogenic ion storage ring combined with a merged electron beam to measure state-specific rate coefficients of dissociative recombination, a process by which electrons destroy molecular ions. We found a pronounced decrease of the electron recombination rates for the lowest rotational states of the helium hydride ion (HeH+), compared with previous measurements at room temperature. The reduced destruction of cold HeH+ translates into an enhanced abundance of this primordial molecule at redshifts of first star and galaxy formation.
The stability of HeH+ to electron bombardment in a cryogenic storage ring suggests its enhanced primordial abundance.
The stability of HeH+ to electron bombardment in a cryogenic storage ring suggests its enhanced primordial abundance.},
language = {en},
number = {6454},
urldate = {2019-08-19},
journal = {Science},
author = {Novotný, Oldřich and Wilhelm, Patrick and Paul, Daniel and Kálosi, Ábel and Saurabh, Sunny and Becker, Arno and Blaum, Klaus and George, Sebastian and Göck, Jürgen and Grieser, Manfred and Grussie, Florian and Hahn, Robert von and Krantz, Claude and Kreckel, Holger and Meyer, Christian and Mishra, Preeti M. and Muell, Damian and Nuesslein, Felix and Orlov, Dmitry A. and Rimmler, Marius and Schmidt, Viviane C. and Shornikov, Andrey and Terekhov, Aleksandr S. and Vogel, Stephen and Zajfman, Daniel and Wolf, Andreas},
month = aug,
year = {2019},
pmid = {31320559},
pages = {676--679},
file = {Novotný et al. - 2019 - Quantum-state–selective electron recombination stu.pdf:/home/puma/.zotero_bibliography/storage/7E7H8HH6/Novotný et al. - 2019 - Quantum-state–selective electron recombination stu.pdf:application/pdf;Novotný et al. - 2019 - Quantum-state–selective electron recombination stu.pdf:/home/puma/.zotero_bibliography/storage/WS43EUAW/Novotný et al. - 2019 - Quantum-state–selective electron recombination stu.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/F8RBA9QV/676.html:text/html}
}
@article{krantz_transverse_2021,
title = {Transverse electron cooling of heavy molecular ions},
volume = {24},
url = {https://link.aps.org/doi/10.1103/PhysRevAccelBeams.24.050101},
doi = {10.1103/PhysRevAccelBeams.24.050101},
abstract = {Transverse electron cooling of heavy molecular ions has been studied at the Test Storage Ring (TSR). Electron beams from a cold GaAs:(Cs,O) photocathode, with kinetic energies down to 31 eV, have been used for cooling of singly-charged ions of masses up to 41 u. We believe that these are the heaviest singly-charged ions for which successful electron cooling has been reported so far. Transverse ion-beam emittances ≪1 μm were reached after typically several seconds of cooling time. The measured transverse cooling rates agree with a simple binary-collision model, assuming a transverse electron temperature of approximately 1 meV/kB. The results serve as benchmark for electron cooling at the new Cryogenic Storage Ring, which uses the same photocathode electron source and is targeting singly-charged ions of even higher mass.},
number = {5},
urldate = {2021-05-03},
journal = {Physical Review Accelerators and Beams},
author = {Krantz, C. and Buhr, H. and Grieser, M. and Lestinsky, M. and Novotný, O. and Novotny, S. and Orlov, D. A. and Repnow, R. and Terekhov, A. S. and Wilhelm, P. and Wolf, A.},
month = may,
year = {2021},
pages = {050101},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/P2P9LTRC/PhysRevAccelBeams.24.html:text/html;Krantz et al. - 2021 - Transverse electron cooling of heavy molecular ion.pdf:/home/puma/.zotero_bibliography/storage/4SKXAS2X/Krantz et al. - 2021 - Transverse electron cooling of heavy molecular ion.pdf:application/pdf}
}
@article{mull_metastable_2021,
title = {Metastable states of {Si}- observed in a cryogenic storage ring},
volume = {104},
url = {https://link.aps.org/doi/10.1103/PhysRevA.104.032811},
doi = {10.1103/PhysRevA.104.032811},
abstract = {We have used the Cryogenic Storage Ring (CSR) at the Max Planck Institute for Nuclear Physics to study long-lived metastable states of the silicon anion. A Si− beam of 58 keV kinetic energy was stored in the ultrahigh cryogenic vacuum of the CSR, employing only electrostatic deflection elements. We used laser systems at various wavelengths to infer information on the decay of the metastable anionic states by selective photodetachment. Our results give evidence of an excited anionic state for which we determine the extremely long lower lifetime limit of 5.7 h at 90\% confidence level, consistent with theoretical predictions for the 2D term. Furthermore, we find an average lifetime of τ=(22.2±2.5) s for the weakly bound 2P states, employing coincidence counting with a pulsed nanosecond laser at 2.45 μm. Using a laser depletion technique, we produce a pure ground term 4S3/2Si− beam, and we quantify the fraction of ions in metastable states in our initial ion sample. We combine our experimental efforts with state-of-the-art multiconfiguration Dirac-Hartree-Fock calculations for the radiative lifetimes of all metastable levels of Si−. We find these calculations to be in excellent agreement with our measurements and to improve previous efforts considerably.},
number = {3},
urldate = {2021-09-09},
journal = {Physical Review A},
author = {Müll, D. and Grussie, F. and Blaum, K. and George, S. and Göck, J. and Grieser, M. and von Hahn, R. and Harman, Z. and Kálosi, Á. and Keitel, C. H. and Krantz, C. and Lyu, C. and Novotný, O. and Nuesslein, F. and Paul, D. and Schmidt, V. C. and Singh, S. and Sunil Kumar, S. and Urbain, X. and Wolf, A. and Kreckel, H.},
month = sep,
year = {2021},
note = {Publisher: American Physical Society},
pages = {032811},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/592NIRAM/PhysRevA.104.html:text/html;Müll et al. - 2021 - Metastable states of Si- observed in a cryogenic s.pdf:/home/puma/.zotero_bibliography/storage/NIBH2WE8/Müll et al. - 2021 - Metastable states of Si- observed in a cryogenic s.pdf:application/pdf}
}
@article{krantz_recommissioning_2021,
title = {Recommissioning of the {CRYRING}@{ESR} {Electron} {Cooler}},
volume = {IPAC2021},
copyright = {Creative Commons Attribution 3.0 Unported},
issn = {2673-5490},
url = {https://jacow.org/ipac2021/doi/JACoW-IPAC2021-TUPAB178.html},
doi = {10.18429/JACOW-IPAC2021-TUPAB178},
abstract = {The heavy-ion storage ring CRYRING has been recommissioned downstream of GSI’s ESR, which it complements as dedicated low-energy machine. A key element of CRYRING@ESR is its electron cooler, which features one of the coldest electron beams available. This enables efficient phase-space cooling and, in addition, provides very high energy resolution when used as internal electron target. We report on technical upgrades that have been made as part of the re-installation of the cooler at GSI/FAIR and share first results obtained after recommissioning.},
language = {en},
urldate = {2021-10-01},
journal = {Proceedings of the 12th International Particle Accelerator Conference},
author = {Krantz, Claude and Andelkovic, Zoran and Brandau, Carsten and Dimopoulou, Christina and Geithner, Wolfgang and Hackler, Thomas and Hannen, Volker and Herfurth, Frank and Hess, Regina and Lestinsky, Michael and Menz, Esther and Reiter, Andreas and Roßbach, Jon and Schippers, Stefan and Schroeder, Claus and Täschner, Alexander and Vorobjev, Gleb and Weinheimer, Christian and Winzen, Daniel},
collaborator = {Liu (Ed.), Lin and M. (Ed.), John, Byrd and Neuenschwander (Ed.), Regis and Renan (Ed.), Picoreti and W. (Ed.), Volker R., Schaa},
year = {2021},
keywords = {Accelerator Physics, MC4: Hadron Accelerators},
pages = {3 pages},
annote = {SeriesInformation
Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil},
file = {Krantz et al. - 2021 - Recommissioning of the CRYRING@ESR Electron Cooler.pdf:/home/puma/.zotero_bibliography/storage/3BJY53U7/Krantz et al. - 2021 - Recommissioning of the CRYRING@ESR Electron Cooler.pdf:application/pdf}
}
@article{kalosi_laser_2022,
title = {Laser {Probing} of the {Rotational} {Cooling} of {Molecular} {Ions} by {Electron} {Collisions}},
volume = {128},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.128.183402},
doi = {10.1103/PhysRevLett.128.183402},
abstract = {We present state-selected measurements of rotational cooling and excitation rates of CH+ molecular ions by inelastic electron collisions. The experiments are carried out at a cryogenic storage ring, making use of a monoenergetic electron beam at matched velocity in combination with state-sensitive laser dissociation of the CH+ ions for simultaneous monitoring of the rotational level populations. Employing storage times of up to 600 s, we create conditions where electron-induced cooling to the J=0 ground state dominates over radiative relaxation, allowing for the experimental determination of inelastic electron collision rates to benchmark state-of-the-art theoretical calculations. On a broader scale, our experiments pave the way to probe inelastic electron collisions for a variety of molecular ions relevant in various plasma environments.},
number = {18},
urldate = {2022-05-04},
journal = {Physical Review Letters},
author = {Kálosi, Ábel and Grieser, Manfred and von Hahn, Robert and Hechtfischer, Ulrich and Krantz, Claude and Kreckel, Holger and Müll, Damian and Paul, Daniel and Savin, Daniel W. and Wilhelm, Patrick and Wolf, Andreas and Novotný, Oldřich},
month = may,
year = {2022},
note = {Publisher: American Physical Society},
pages = {183402},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/KM4VNMNX/PhysRevLett.128.html:text/html;Kálosi et al. - 2022 - Laser Probing of the Rotational Cooling of Molecul.pdf:/home/puma/.zotero_bibliography/storage/C3QUMRG9/Kálosi et al. - 2022 - Laser Probing of the Rotational Cooling of Molecul.pdf:application/pdf;suppl-ch-laser-resubm.pdf:/home/puma/.zotero_bibliography/storage/KFSMC2ND/suppl-ch-laser-resubm.pdf:application/pdf}
}
@article{lestinsky_first_2022,
title = {First {Experiments} with {CRYRING}@{ESR}},
volume = {10},
copyright = {http://creativecommons.org/licenses/by/3.0/},
issn = {2218-2004},
url = {https://www.mdpi.com/2218-2004/10/4/141},
doi = {https://doi.org/10.3390/atoms10040141},
abstract = {The low-energy heavy ion storage ring CRYRING was transported from Stockholm to Darmstadt, modernized and reconfigured, and recommissioned as CRYRING@ESR. The machine is now in operation with all installations in service and is available as a user facility for experiments proposed through the SPARC collaboration. During the 2020–2022 period, we brought a number of experimental installations into service and used them to measure first data: the ultra-cold electron cooler for merged-beam electron–ion collisions, the gas jet target for atomic collisions, a next-generation microcalorimeter-based X-ray spectroscopy setup, and others. Ions can be injected either in low charge states from a local ion source through a 300 keV/u RFQ linac, or in high charge states from the GSI accelerator chain through ESR. This allows for very broad access to ions across the entire periodic table. CRYRING@ESR is able to de- or accelerate ions and cool and store beams of isotopically pure species in a desired charge state. While the analysis is still largely ongoing, the first experimental data already show that the machine reached its expected performance level, and our high expectations regarding achievable resolution in spectroscopy experiments have been fulfilled. With access to new classes of ions available through ESR injection and a new generation of experimental instrumentation, CRYRING@ESR is a unique facility for experiments with heavy, highly charged ions. Here, we will review our present setup and machine performance, discuss the data from our first commissioning experiments and briefly preview the upcoming new installations for the coming years.},
language = {en},
number = {4},
urldate = {2022-11-16},
journal = {Atoms},
author = {Lestinsky, Michael and Menz, Esther Babette and Danared, Håkan and Krantz, Claude and Lindroth, Eva and Andelkovic, Zoran and Brandau, Carsten and Bräuning-Demian, Angela and Fedotova, Svetlana and Geithner, Wolfgang and Herfurth, Frank and Kalinin, Anton and Kraus, Ingrid and Spillmann, Uwe and Vorobyev, Gleb and Stöhlker, Thomas},
month = dec,
year = {2022},
note = {Number: 4
Publisher: Multidisciplinary Digital Publishing Institute},
keywords = {atomic physics, beam cooling, beam storage, highly charged ions},
pages = {141},
file = {Lestinsky et al. - 2022 - First Experiments with CRYRING@ESR.pdf:/home/puma/.zotero_bibliography/storage/4YPR85P7/Lestinsky et al. - 2022 - First Experiments with CRYRING@ESR.pdf:application/pdf;Snapshot:/home/puma/.zotero_bibliography/storage/J84MLNM8/htm.html:text/html}
}
@article{paul_experimental_2022,
title = {Experimental {Determination} of the {Dissociative} {Recombination} {Rate} {Coefficient} for {Rotationally} {Cold} {CH}+ and {Its} {Implications} for {Diffuse} {Cloud} {Chemistry}},
volume = {939},
issn = {0004-637X},
url = {https://dx.doi.org/10.3847/1538-4357/ac8e02},
doi = {10.3847/1538-4357/ac8e02},
abstract = {Observations of CH+ are used to trace the physical properties of diffuse clouds, but this requires an accurate understanding of the underlying CH+ chemistry. Until this work, the most uncertain reaction in that chemistry was dissociative recombination (DR) of CH+. Using an electron–ion merged-beams experiment at the Cryogenic Storage Ring, we have determined the DR rate coefficient of the CH+ electronic, vibrational, and rotational ground state applicable for different diffuse cloud conditions. Our results reduce the previously unrecognized order-of-magnitude uncertainty in the CH+ DR rate coefficient to ∼20\% and are applicable at all temperatures relevant to diffuse clouds, ranging from quiescent gas to gas locally heated by processes such as shocks and turbulence. Based on a simple chemical network, we find that DR can be an important destruction mechanism at temperatures relevant to quiescent gas. As the temperature increases locally, DR can continue to be important up to temperatures of ∼600 K, if there is also a corresponding increase in the electron fraction of the gas. Our new CH+ DR rate-coefficient data will increase the reliability of future studies of diffuse cloud physical properties via CH+ abundance observations.},
language = {en},
number = {2},
urldate = {2022-11-14},
journal = {The Astrophysical Journal},
author = {Paul, Daniel and Grieser, Manfred and Grussie, Florian and Hahn, Robert von and Isberner, Leonard W. and Kálosi, Ábel and Krantz, Claude and Kreckel, Holger and Müll, Damian and Neufeld, David A. and Savin, Daniel W. and Schippers, Stefan and Wilhelm, Patrick and Wolf, Andreas and Wolfire, Mark G. and Novotný, Oldřich},
month = nov,
year = {2022},
note = {Publisher: The American Astronomical Society},
pages = {122},
file = {Paul et al. - 2022 - Experimental Determination of the Dissociative Rec.pdf:/home/puma/.zotero_bibliography/storage/PGEZXISY/Paul et al. - 2022 - Experimental Determination of the Dissociative Rec.pdf:application/pdf}
}
@article{krantz_operational_2023,
title = {Operational tests of {CRYRING}@{ESR} without electron cooler solenoid compensation},
copyright = {Creative Commons Attribution 4.0 International},
issn = {2673-5490},
url = {https://jacow.org/ipac2023/doi/jacow-ipac2023-tupm079},
doi = {10.18429/JACOW-IPAC2023-TUPM079},
abstract = {We have tested operation of FAIR’s low-energy ion storage ring CRYRING@ESR with uncompensated electron cooler solenoid. With its standard working point on the lowestorder difference resonance, a second solenoid is normally used to cancel betatron coupling introduced by the cooler’s magnetic field. In operation with a D+ test beam, we found that omission of the compensation solenoid did not lead to a notable deterioration of beam intensity, quality, or cooling time, though the expected coupling of betatron motion is then clearly observed.},
language = {en},
urldate = {2023-12-13},
author = {Krantz, Claude and Andelkovic, Zoran and Dimopoulou, Christina and Fedotova, Svetlana and Geithner, Wolfgang and Herfurth, Frank and Heß, Regina and Kraus, Ingrid and Khammee, Surawadee and Lestinsky, Michael and Reiter, Andreas and Roßbach, Jon and Trotsenko, Sergiy and Vorobyev, Gleb},
month = sep,
year = {2023},
note = {Artwork Size: 2387-2390 pages, 0.67 MB
ISBN: 9783954502318
Medium: PDF
Publisher: JACoW Publishing},
keywords = {Accelerator Physics, mc4-a24-accelerators-and-storage-rings-other - MC4.A24: Accelerators and Storage Rings, Other, mc4-hadron-accelerators - MC4: Hadron Accelerators},
pages = {2387--2390 pages, 0.67 MB},
file = {Krantz et al. - 2023 - Operational tests of CRYRING@ESR without electron .pdf:/home/puma/.zotero_bibliography/storage/Z983CLJW/Krantz et al. - 2023 - Operational tests of CRYRING@ESR without electron .pdf:application/pdf}
}
@article{krantz_operational_2024,
title = {Operational tests of {CRYRING}@{ESR} without electron cooler solenoid compensation},
volume = {2687},
issn = {1742-6596},
url = {https://dx.doi.org/10.1088/1742-6596/2687/5/052026},
doi = {10.1088/1742-6596/2687/5/052026},
abstract = {We have tested operation of FAIR’s low-energy ion storage ring CRYRING@ESR with uncompensated electron cooler solenoid. With its standard working point on the lowest-order difference resonance, a second solenoid is normally used to cancel betatron coupling introduced by the cooler’s magnetic field. In operation with a D+ test beam, we found that omission of the compensation solenoid did not lead to a notable deterioration of beam intensity, quality, or cooling time, though the expected coupling of betatron motion is then clearly observed.},
language = {en},
number = {5},
urldate = {2024-01-28},
journal = {Journal of Physics: Conference Series},
author = {Krantz, C. and Andelkovic, Z. and Dimopoulou, C. and Fedotova, S. and Geithner, W. and Herfurth, F. and Heß, R. and Kraus, I. and Khammee, S. and Lestinsky, M. and Reiter, A. and Roβbach, J. and Trotsenko, S. and Vorobyev, G.},
month = jan,
year = {2024},
note = {Publisher: IOP Publishing},
pages = {052026},
file = {Krantz et al. - 2024 - Operational tests of CRYRING@ESR without electron .pdf:/home/puma/.zotero_bibliography/storage/U4RVRD2A/Krantz et al. - 2024 - Operational tests of CRYRING@ESR without electron .pdf:application/pdf}
}
@article{schmidt_autodetachment_2024,
title = {Autodetachment of {Diatomic} {Carbon} {Anions} from {Long}-{Lived} {High}-{Rotation} {Quartet} {States}},
volume = {133},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.133.183001},
doi = {10.1103/PhysRevLett.133.183001},
abstract = {We show that strong molecular rotation drastically modifies the autodetachment of C−2 ions in the lowest quartet electronic state 𝑎4Σ+𝑢. In the strong-rotation regime, levels of this state only decay by a process termed “rotationally assisted” autodetachment, whose theoretical description is worked out based on the nonlocal resonance model. For autodetachment linked with the exchange of six rotational quanta, the results reproduce a prominent, hitherto unexplained electron emission signal with a mean decay time near 3 ms, observed on stored C−2 ions from a hot ion source.},
number = {18},
urldate = {2024-11-01},
journal = {Physical Review Letters},
author = {Schmidt, Viviane C. and Čurík, Roman and Ončák, Milan and Blaum, Klaus and George, Sebastian and Göck, Jürgen and Grieser, Manfred and Grussie, Florian and von Hahn, Robert and Krantz, Claude and Kreckel, Holger and Novotný, Oldřich and Spruck, Kaija and Wolf, Andreas},
month = oct,
year = {2024},
note = {Publisher: American Physical Society},
pages = {183001},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/RTMTL4PZ/PhysRevLett.133.html:text/html;Schmidt et al. - 2024 - Autodetachment of Diatomic Carbon Anions from Long.pdf:/home/puma/.zotero_bibliography/storage/5ULL8P29/Schmidt et al. - 2024 - Autodetachment of Diatomic Carbon Anions from Long.pdf:application/pdf}
}
@article{schmidt_unimolecular_2024,
title = {Unimolecular processes in diatomic carbon anions at high rotational excitation},
volume = {110},
url = {https://link.aps.org/doi/10.1103/PhysRevA.110.042828},
doi = {10.1103/PhysRevA.110.042828},
abstract = {On the millisecond to second time scale, stored beams of diatomic carbon anions C2− from a sputter ion source feature unimolecular decay of yet unexplained origin by electron emission and fragmentation. To account for the magnitude and time dependence of the experimental rates, levels with high rotational and vibrational excitation are modeled for the lowest electronic states of C2−, also including the lowest quartet potential. Energies, spontaneous radiative decay rates (including spin-forbidden quartet-level decay), and tunneling dissociation rates are determined for a large number of highly excited C2− levels and their population in sputter-type ion sources is considered. For the quartet levels, the stability against autodetachment is addressed and recently calculated rates of rotationally assisted autodetachment are applied. Nonadiabatic vibrational autodetachment rates of high vibrational levels in the doublet C2− ground potential are also calculated. The results are combined to model the experimental unimolecular decay signals. Comparison of the modeled to the experimental rates measured at the cryogenic storage ring facility CSR gives strong evidence that C2− ions in quasistable levels of the quartet electronic states are the so far unidentified source of unimolecular decay.},
number = {4},
urldate = {2024-11-01},
journal = {Physical Review A},
author = {Schmidt, Viviane C. and Čurík, Roman and Ončák, Milan and Blaum, Klaus and George, Sebastian and Göck, Jürgen and Grieser, Manfred and Grussie, Florian and von Hahn, Robert and Krantz, Claude and Kreckel, Holger and Novotný, Oldřich and Spruck, Kaija and Wolf, Andreas},
month = oct,
year = {2024},
note = {Publisher: American Physical Society},
pages = {042828},
file = {APS Snapshot:/home/puma/.zotero_bibliography/storage/I5A688XE/PhysRevA.110.html:text/html;Schmidt et al. - 2024 - Unimolecular processes in diatomic carbon anions a.pdf:/home/puma/.zotero_bibliography/storage/2SFJXJLQ/Schmidt et al. - 2024 - Unimolecular processes in diatomic carbon anions a.pdf:application/pdf}
}
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