skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Development of Auger-Electron-Ion Coincidence Spectrometer to Study Decay Dynamics of Core Ionized Molecules

Abstract

A new electron-ion coincidence spectrometer for studies on decay dynamics of core excited/ionized molecules has been developed. The coincidence spectrometer consists of a double toroidal electron analyzer (DTA) and a three-dimensional ion momentum spectrometer, which are followed by time- and position-sensitive detectors (PSDs). The Auger electron is energy analyzed by the DTA, while the ions are extracted from the interaction region by a pulsed electric field triggered by the detection signal of the electron, and the time-of-flight of the ions and their position information on the ion PSD are obtained. The design and performance of the coincidence spectrometer are reported.

Authors:
; ;  [1]
  1. UVSOR Facility, Institute for Molecular Science, Nishigonaka 38, Myodaiji, Okazaki 444-8585 (Japan)
Publication Date:
OSTI Identifier:
21049357
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436417; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; AUGER ELECTRON SPECTROSCOPY; COINCIDENCE SPECTROMETRY; DIFFERENTIAL THERMAL ANALYSIS; ELECTRIC FIELDS; ELECTRONS; IONS; MOLECULES; PERFORMANCE; PHOTOIONIZATION; POSITION SENSITIVE DETECTORS; THREE-DIMENSIONAL CALCULATIONS; TIME-OF-FLIGHT METHOD

Citation Formats

Kaneyasu, T., Hikosaka, Y., and Shigemasa, E. Development of Auger-Electron-Ion Coincidence Spectrometer to Study Decay Dynamics of Core Ionized Molecules. United States: N. p., 2007. Web. doi:10.1063/1.2436417.
Kaneyasu, T., Hikosaka, Y., & Shigemasa, E. Development of Auger-Electron-Ion Coincidence Spectrometer to Study Decay Dynamics of Core Ionized Molecules. United States. doi:10.1063/1.2436417.
Kaneyasu, T., Hikosaka, Y., and Shigemasa, E. Fri . "Development of Auger-Electron-Ion Coincidence Spectrometer to Study Decay Dynamics of Core Ionized Molecules". United States. doi:10.1063/1.2436417.
@article{osti_21049357,
title = {Development of Auger-Electron-Ion Coincidence Spectrometer to Study Decay Dynamics of Core Ionized Molecules},
author = {Kaneyasu, T. and Hikosaka, Y. and Shigemasa, E.},
abstractNote = {A new electron-ion coincidence spectrometer for studies on decay dynamics of core excited/ionized molecules has been developed. The coincidence spectrometer consists of a double toroidal electron analyzer (DTA) and a three-dimensional ion momentum spectrometer, which are followed by time- and position-sensitive detectors (PSDs). The Auger electron is energy analyzed by the DTA, while the ions are extracted from the interaction region by a pulsed electric field triggered by the detection signal of the electron, and the time-of-flight of the ions and their position information on the ion PSD are obtained. The design and performance of the coincidence spectrometer are reported.},
doi = {10.1063/1.2436417},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
  • The N{sub 23}VV Auger spectrum of Ru has been measured in coincidence with 4p{sub 1/2} and with 4p{sub 3/2} photoelectrons. Unlike other metals that exhibit bandlike Auger decays, we find that the two Auger spectra are not shifted by the difference in core level binding energies. A consistent description of these transitions and the core level line shape requires consideration of the relativistic multiplet splitting in the intermediate core hole state and two-valence-hole Auger final state. The results suggest that the large linewidth of the 4p levels is primarily due to multiplet splitting, and that an N{sub 2}(N{sub 3}N{sub 45})N{submore » 45}N{sub 45} super-Coster-Kronig transition is only a minor decay channel. (c) 2000 The American Physical Society.« less
  • Multielectron coincidence data for triple ionization of krypton have been recorded above the 3d ionization threshold at two photon energies (140 and 150 eV). Three principal transition pathways have been observed, two involving double Auger transitions from Kr{sup +}, and one involving single Auger transitions from Kr{sup 2+} created by direct single-photon double ionization. The decay of the 3d{sup 9} {sup 2}D{sub 5/2,3/2} states in Kr{sup +} has been analyzed in some detail and is found to be strongly dominated by cascade processes where two electrons with well-defined energies are emitted. The decay paths leading to the 4s{sup 2}4p{sup 3}more » {sup 4}S, {sup 2}D, and {sup 2}P states of Kr{sup 3+} are analyzed and energies of seven intermediate states in Kr{sup 2+} are given. A preliminary investigation of the decay paths from Kr{sup +} 3d{sup 9}4p{sup 5}nl shake-up states has also been carried out.« less
  • We have carried out a coincidence experiment between energy-resolved resonant Auger electrons and mass-resolved ions on CH{sub 3}F molecules following F 1s and C 1s excitation to the lowest unoccupied C-F antibonding molecular orbital {sigma}{sub CF}{sup .} We found a strong enhancement of the F{sup +} or CH{sup +} ion production in coincidence with the F KVV and C KVV spectator Auger electrons, respectively, in the wide binding energy range of 28-36 eV. This site-selective ion production is interpreted as a consequence of the resonant Auger emission taking place in the transient region where the C-F elongation caused by themore » core excitation transforms the molecular valence orbitals gradually into nonoverlapping valence orbitals of each fragment.« less
  • We have studied the electronic decay of an oxygen 1s core hole in N/sub 2/O and the subsequent fragmentation into ions. Coincidence studies between the energy resolved Auger electrons and the ions reveal the individual decay channels for the various doubly charged ionic configurations populated in the Auger decay of the core hole. The site specificity in these events is not absolutely confined to breaking only the O--NN bond, even though the excitation of a core hole at the oxygen site in the initial absorption event is localized. This localization is to some extent preserved in the Auger decay, whichmore » favors the participation of valence electrons having wave functions with a large overlap at the site of the initial oxygen core hole. However some of these electrons are also crucial in forming the ON--N bond or the bonding structure of the molecule as a whole, such that removal of these electrons in the Auger decay results in the total destruction of the molecular bond.« less
  • An Auger-electron–photoion coincidence (AEPICO) method has been applied to study the stability and dissociation dynamics of dicationic states after the N K-shell photoionization of nitrogen molecules. From time-of-flight and kinetic energy analyses of the product ions, we have obtained coincident Auger spectra associated with metastable states of N{sub 2}{sup ++} ions and dissociative states leading to N{sub 2}{sup ++} → N{sup +} + N{sup +} and N{sup ++} + N. To investigate the production of dissociative states, we present two-dimensional AEPICO maps which reveal the correlations between the binding energies of the Auger final states and the ion kinetic energymore » release. These correlations have been used to determine the dissociation limits of individual Auger final states.« less