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Title: Momentum imaging spectrometer for molecular fragmentation dynamics induced by pulsed electron beam

A momentum imaging spectrometer has been built for studying the electron impact molecular fragmentation dynamics. The setup consists of a pulsed electron gun and a time of flight system as well as a two-dimensional time and position sensitive multi-hit detector. The charged fragments with kinetic energy up to 10 eV can be detected in 4π solid angles and their three-dimensional momentum vectors can be reconstructed. The apparatus is tested by electron impact ionization of Ar and dissociative ionization of CO{sub 2}. By analyzing the ion-ion coincidence spectra, the complete and incomplete Coulomb fragmentation channels for CO{sub 2}{sup 2+} and CO{sub 2}{sup 3+} are identified. The kinetic energy release (KER) and angular correlation for the two-body breakup channel CO{sub 2}{sup 2+*}→ O{sup +}+ CO{sup +} are reported. The peak value of total KER is found to be 6.8 eV which is consistent with the previous photoion-photoion coincidence studies, and the correlation angle of O{sup +} and CO{sup +} is also explicitly determined to be 172.5°.
Authors:
; ; ; ;  [1]
  1. Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
22220212
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 84; Journal Issue: 12; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 74 ATOMIC AND MOLECULAR PHYSICS; ANGULAR CORRELATION; ARGON; BERYLLIUM 6; CARBON DIOXIDE; CARBON MONOXIDE; COINCIDENCE SPECTROMETRY; ELECTRON BEAMS; ELECTRONS; EV RANGE; FRAGMENTATION; IONIZATION; KINETIC ENERGY; OXYGEN IONS; POSITION SENSITIVE DETECTORS; PULSES; TIME-OF-FLIGHT SPECTROMETERS