Photoabsorption, photoionization, and Auger processes at the carbon K edge in C H3 i

De Fanis, Alberto; Forbes, Ruaridh; Pratt, Stephen T.; Bozek, John D.; Besley, Nicholas A.; Milosavljevi?, Aleksandar R.; Nicolas, Christophe; Holland, David M. P.

Abstract

© 2020 American Physical Society. The dynamics of photoabsorption, photoionization, and the associated Auger decay have been investigated at the carbon K edge in methyl iodide (CH3I) using linearly polarized synchrotron radiation. Ion yield measurements were used to investigate transitions in the pre-edge region due to excitations into either unoccupied valence or Rydberg states. The assignment of these transitions was achieved through comparison with theoretical x-ray absorption spectra calculated using time-dependent density functional theory, within the Tamm-Dancoff approximation. Several of the Rydberg states belonging to series converging onto the C1s ionization limit exhibit significant vibrational structure that is also interpreted using theoretical calculations. The C1s in CH3I photoelectron spectrum was measured, and the observed vibrational structure was assigned with the aid of theoretical predictions. Polarization dependent, resonantly excited, valence shell photoelectron spectra were recorded at photon energies coinciding with the C1s→σ∗, C1s→6sa1 and C1s→6pe transitions in CH3I, thereby allowing photoelectron angular distributions to be determined. The nonresonantly excited C(KVV) Auger electron spectrum was measured and some of the features observed at high kinetic energies were attributed to transitions into valence orbitals possessing significant iodine character. The contributions of participator and spectator Auger decay to the resonantly excited photoelectron spectra have been assessed. The influence of participator decay appears minor whereas spectator decay results in the enhanced population of satellite states.

Citation

De Fanis, A., Forbes, R., Pratt, S. T., Bozek, J. D., Besley, N. A., Milosavljević, A. R., …Holland, D. M. P. (2020). Photoabsorption, photoionization, and Auger processes at the carbon K edge in C H3 i. Physical Review A, 101(2), Article 023408. https://doi.org/10.1103/PhysRevA.101.023408

• Journal Article Type: Article
• Acceptance Date: Jan 21, 2020
• Online Publication Date: Feb 14, 2020
• Publication Date: Feb 1, 2020
• Deposit Date: Feb 17, 2020
• Journal: Physical Review A
• Print ISSN: 2469-9926
• Electronic ISSN: 2469-9934
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 101
• Issue: 2
• Article Number: 023408
• DOI: https://doi.org/10.1103/PhysRevA.101.023408
• Public URL: https://nottingham-repository.worktribe.com/output/3978284
• Publisher URL: https://journals.aps.org/pra/pdf/10.1103/PhysRevA.101.023408
• Additional Information: ©2020 American Physical Society.