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Title: Study of inner-shell vacancy cascades by coincidence techniques

Abstract

An inner-shell vacancy in an atom decays by an intricate combination of Auger and fluorescence processes. The interrelation between these processes is not well understood because traditional studies of core-excited atoms focus on only one of the many particles that participate in the relaxation - largely ignoring the other components and the correlations between them. To understand these correlations we developed a coincidence technique that uses coincident detection of X-rays and electrons to select decay pathways that involve emission of both an X-ray photon and electrons. In the first application of this technique, the Ar 1s photoelectron spectrum was recorded selectively in coincidence with X-ray fluorescence to eliminate the asymmetric broadening and shifting of the energy distribution which results due to post-collision interaction with K-Auger electrons. This allowed the direct observation of the interaction between the photoelectron and the decay of core holes created after the initial photoionization event. We have also applied this technique to the much more complex problem of understanding Auger-electron spectra produced by vacancy cascades following inner-shell excitation. For example, we previously recorded non-coincident electron spectra of L{sub 2,3}MM Auger transitions following K-shell excitation of argon. Interpretation of these spectra is difficult because they are complicatedmore » and consist of many overlapping or unresolved Auger transitions between different ionic states.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab., IL (United States)
OSTI Identifier:
166504
Report Number(s):
ANL-95/14
ON: DE96000985; TRN: 95:007970-0220
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Aug 1995; Related Information: Is Part Of Physics Division Annual Report, April 1, 1994--March 31, 1995; Henning, W.F.; PB: 207 p.
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; INNER-SHELL EXCITATION; COINCIDENCE METHODS; PROGRESS REPORT; X-RAY FLUORESCENCE ANALYSIS; PHOTOIONIZATION

Citation Formats

LeBrun, T., Arp, U., MacDonald, M., and Southworth, S. H. Study of inner-shell vacancy cascades by coincidence techniques. United States: N. p., 1995. Web. doi:10.2172/166504.
LeBrun, T., Arp, U., MacDonald, M., & Southworth, S. H. Study of inner-shell vacancy cascades by coincidence techniques. United States. https://doi.org/10.2172/166504
LeBrun, T., Arp, U., MacDonald, M., and Southworth, S. H. Tue . "Study of inner-shell vacancy cascades by coincidence techniques". United States. https://doi.org/10.2172/166504. https://www.osti.gov/servlets/purl/166504.
@article{osti_166504,
title = {Study of inner-shell vacancy cascades by coincidence techniques},
author = {LeBrun, T. and Arp, U. and MacDonald, M. and Southworth, S. H.},
abstractNote = {An inner-shell vacancy in an atom decays by an intricate combination of Auger and fluorescence processes. The interrelation between these processes is not well understood because traditional studies of core-excited atoms focus on only one of the many particles that participate in the relaxation - largely ignoring the other components and the correlations between them. To understand these correlations we developed a coincidence technique that uses coincident detection of X-rays and electrons to select decay pathways that involve emission of both an X-ray photon and electrons. In the first application of this technique, the Ar 1s photoelectron spectrum was recorded selectively in coincidence with X-ray fluorescence to eliminate the asymmetric broadening and shifting of the energy distribution which results due to post-collision interaction with K-Auger electrons. This allowed the direct observation of the interaction between the photoelectron and the decay of core holes created after the initial photoionization event. We have also applied this technique to the much more complex problem of understanding Auger-electron spectra produced by vacancy cascades following inner-shell excitation. For example, we previously recorded non-coincident electron spectra of L{sub 2,3}MM Auger transitions following K-shell excitation of argon. Interpretation of these spectra is difficult because they are complicated and consist of many overlapping or unresolved Auger transitions between different ionic states.},
doi = {10.2172/166504},
url = {https://www.osti.gov/biblio/166504}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {8}
}