| Zugriffsnummer | 37085 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Unambiguous observation of triple-Auger decay in near-K-edge multiple photoionization of C+ ions |
| Autor(in); Institution |
Müller, A.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY
Borovik, A.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY; Justus-Liebig-Universität Giessen, I. Physikalisches Institut, Giessen, GERMANY
Buhr, Ticia; 6.5, Strahlenwirkung, PTB-Braunschweig; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY
Hellhund, J.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY
Holste, K.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY; Justus-Liebig-Universität Giessen, I. Physikalisches Institut, Giessen, GERMANY
Kilcoyne, A. L. D.; Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, USA
Klumpp, S.; Universität Hamburg, Institut für Experimentalphysik, Hamburg, GERMANY
Martins, M.; Universität Hamburg, Institut für Experimentalphysik, Hamburg, GERMANY
Ricz, S.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY; Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, HUNGARY
Viefhaus, J.; FS-PE, DESY, Hamburg, GERMANY
Schippers, S.; Justus-Liebig-Universität Giessen, Institut für Atom- und Molekülphysik, Giessen, GERMANY; Justus-Liebig-Universität Giessen, I. Physikalisches Institut, Giessen, GERMANY
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| Quelle/Jahr | ECAMP 12, 12th European Conference on Atoms, Molecules and Photons: Extended abstracts:(2016), 274 |
| Availability | [Online only] |
| URL | |
| Konferenzangaben | 12th European Conference on Atoms, Molecules and Photons, Frankfurt am Main, 05-09, September, 2016, Germany |
| Freie Schlagworte | interactions of photons with charged particles ; photoionization ; synchrotron radiation ; Auger process |
| Zusammenfassung | Single, double and triple photoionization of C+ ions by a single photon have been investigated in the energy range 286 to 326 eV. Absolute cross sections have been measured employing the photon-ion spectrometer PIPE at the PETRA III synchrotron radiation source in Hamburg. Different from previous photoionization experiments involving the K shell the present measurement covered a much broader energy range and multiple ionization was studied in detail. We were thus able to unambiguously observe triple-Auger decay processes in which specific K-vacancy terms of C+ were selectively excited from the ground state by irradiation with narrow-bandwidth VUV photons. Subsequent to the decay of the intermediate resonantly excited K-vacancy terms, product ions C2+, C3+ and C4+ were recorded. Fig. 1 shows the experimental cross sections for processes in which a K-shell electron is excited to the L shell according to γ+C+(1s22s22p 2P)→C+(1s2s22p2 2D,2P)→C1+m+(1s22ℓ3−m)+me leading to net photoionization with m = 1,2,3. Net triple ionization resulted in the production of C4+(1s2) (corresponding to m = 3), i. e., of a heliumlike ion with no electron left in the L shell. Clearly, the K vacancy produced by 1s→2p photoexcitation in the first step has to be filled during the subsequent production of C4+ because otherwise there would not be enough energy available to release even a single electron from C+. The fact that no electrons are left in the L shell after the release of three electrons excludes the possibility of an Auger cascade. By making use of the outstanding brightness of PETRA III and the sensitivity of our experimental setup PIPE the natural linewidths of the intermediate resonant states could be measured. By combining all the information obtained in the experiment, the absolute transition rates for radiative as well as single and multiple Auger decays were inferred. The triple-Auger decay rate was found to be approximately 2×1010 s-1 for the C+(1s2s22p2 2D) and 1×1010 s-1 for the C+(1s2s22p2 2P) intermediate resonantly-excited terms investigated in this study. Both decay rates are estimated to have a 50% uncertainty. The ratios of single- to double- to triple-Auger rates of the 2D and 2P terms are about 100 : 2.7 : 0.013 and 100 : 3.3 : 0.013, respectively. |
Zitierung
Müller, A., Borovik, A., Buhr, T., Hellhund, J., Holste, K., Kilcoyne, A. L. D., Klumpp, S., Martins, M., Ricz, S., Viefhaus, J., & Schippers, S. (2016). Unambiguous observation of triple-Auger decay in near-K-edge multiple photoionization of C⁺ ions. 12th European Conference on Atoms, Molecules and Photons, Frankfurt am Main, 05-09, September, 2016, Germany.