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| HAL: in2p3-00420485, version 1 |
| DOI: 10.1103/PhysRevA.81.012711 |
| Detailed view |  Export this paper |
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| Physical Review A: Atomic, Molecular and Optical Physics 81 (2010) 012711 (10 pages) |
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| 20-150 keV proton impact induced ionization of uracil: fragmentation ratios and branching ratios for electron capture and direct ionization |
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| J. Tabet 1S. Eden 2 |
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| (2010) |
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| Fragmentation ratios have been measured for ionization and dissociative ionization for 20-150 keV (0.9-2.4 v0) proton collisions with gas-phase uracil molecules. Through event-by-event determination of the post-collision projectile charge, it is possible for the first time for such a key biomolecule to distinguish between electron capture (EC) by the incident proton and direct ionization (DI) without projectile neutralization. While the same fragment ion groups are observed in the mass spectrum for both processes, electron capture induces dissociation with greater efficiency than direct ionization in the impact energy range of 35-150 keV (1.2-2.4 v0). In this range electron capture is also less abundant than direct ionization with a branching ratio for electron capture / total ionization of < 50%. Moreover, whereas fragmentation ratios do not change with energy in case of electron capture, direct ionization mass spectra show a tendency for increased fragmentation at lower impact energies. |
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| 1: | Institut de Physique Nucléaire de Lyon (IPNL) |
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CNRS : UMR5822 – IN2P3 – Université Claude Bernard - Lyon I |
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| 2: | Department of Physics and Astronomy |
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Open University |
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| 3: | Université Hassan II-Mohammedia, Faculté des Sciences Ben M'Sik (LPMC) |
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Université Hassan II-Mohammedia |
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| 4: | Institut für Ionenphysik und Angewandte Physik |
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Leopold Franzens Universität |
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| Subject(s) | : | Physics/High Energy Physics - Experiment Physics/Physics/Chemical Physics |
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| Uracil – proton impact – ionization – dissociative ionization – electron capture – mass spectrometry |
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| Attached file list to this document: | |||||
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| in2p3-00420485, version 1 | |
| http://hal.in2p3.fr/in2p3-00420485/en/ | |
| oai:hal.in2p3.fr:in2p3-00420485 | |
| From: Dominique Girod | |
| Submitted for: | |
| Submitted on: Tuesday, 29 September 2009 10:58:10 | |
| Updated on: Tuesday, 9 March 2010 15:25:59 | |
