Fragmentation of methanol molecules after core excitation and core ionization studied by negative-ion/positive-ion coincidence experiments
| Autor: | Rami Sankari, Antti Kivimäki, Christian Stråhlman, Robert Richter |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
molecular physics
Photon 010304 chemical physics Chemistry Photon energy sychrotron radiation 01 natural sciences Molecular physics Auger Ion Fragmentation (mass spectrometry) Physics::Plasma Physics Ionization Naturvetenskap 0103 physical sciences Molecule Physical and Theoretical Chemistry Natural Sciences 010306 general physics Excitation |
| Popis: | We have studied the fragmentation of the methanol molecule after core excitation and core ionization by observing coincidences between negative and positive ions. Five different negative ions (H–, C–, CH–, O–, and OH–) were observed at both the C 1s and O 1s edges. As negative ion formation occurs after resonant and normal Auger decay of core–hole states, it is necessarily linked with the release of positively charged fragments. Our data show that such fragmentation can happen in many different ways: We found approximately 30 negative-ion/positive-ion/positive-ion coincidence (NIPIPICO) channels. All involve only singly charged positive ions. Fragmentation channels leading to atomic ions are the most probable, but positive molecular ions are also frequently found in the context of anion formation. Coincidence yields as a function of photon energy were determined for the most intense NIPIPICO channels. Adding together the data measured at different photon energies, we could also verify the occurrence of four-ion coincidences, which involved one negative ion (H– or O–) and three positive ions. |
| Databáze: | OpenAIRE |
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