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Title: Electron-Impact Dissociation of CH 2 + Ions: Measurement of CH + and C + Fragment Ions

Abstract

Absolute cross sections for electron-impact dissociation of CH 2 + producing CH + and C + fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 11% near the cross section peak. The cross sections are nearly identical for energies above 15 eV, but they are dramatically different at lower energies. The CH + channel exhibits a strong peak rising from an observed threshold of about 6 eV; the C+ channel is relatively flat down to the lowest measured energy. Ionization cross sections for the CH 2 + ion are also presented.

Authors:
 [1];  [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
930893
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review A; Journal Volume: 75; Journal Issue: 5
Country of Publication:
United States
Language:
English
Subject:
Electron-Impact Dissociation

Citation Formats

Vane, C Randy, Bahati Musafiri, Eric, Bannister, Mark E, and Thomas, Richard D. Electron-Impact Dissociation of CH2+ Ions: Measurement of CH+ and C+ Fragment Ions. United States: N. p., 2007. Web. doi:10.1103/PhysRevA.75.052715.
Vane, C Randy, Bahati Musafiri, Eric, Bannister, Mark E, & Thomas, Richard D. Electron-Impact Dissociation of CH2+ Ions: Measurement of CH+ and C+ Fragment Ions. United States. doi:10.1103/PhysRevA.75.052715.
Vane, C Randy, Bahati Musafiri, Eric, Bannister, Mark E, and Thomas, Richard D. Mon . "Electron-Impact Dissociation of CH2+ Ions: Measurement of CH+ and C+ Fragment Ions". United States. doi:10.1103/PhysRevA.75.052715.
@article{osti_930893,
title = {Electron-Impact Dissociation of CH2+ Ions: Measurement of CH+ and C+ Fragment Ions},
author = {Vane, C Randy and Bahati Musafiri, Eric and Bannister, Mark E and Thomas, Richard D},
abstractNote = {Absolute cross sections for electron-impact dissociation of CH2+ producing CH+ and C+ fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 11% near the cross section peak. The cross sections are nearly identical for energies above 15 eV, but they are dramatically different at lower energies. The CH+ channel exhibits a strong peak rising from an observed threshold of about 6 eV; the C+ channel is relatively flat down to the lowest measured energy. Ionization cross sections for the CH2+ ion are also presented.},
doi = {10.1103/PhysRevA.75.052715},
journal = {Physical Review A},
number = 5,
volume = 75,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Absolute cross sections for electron-impact dissociation of CH{sub 2}{sup +} producing CH{sup +} and C{sup +} fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 11% near the cross section peak. The cross sections are nearly identical for energies above 15 eV, but they are dramatically different at lower energies. The CH{sup +} channel exhibits a strong peak rising from an observed threshold of about 6 eV; the C{sup +} channel is relatively flat down to the lowest measured energy. Ionization cross sections for the CH{sub 2}{sup +} ionmore » are also presented.« less
  • Using a crossed electron-ion beams method, we measured absolute cross sections for electron-impact dissociation of the CD 3 + molecular ions producing CD 2 + fragment ions and CH 3 + ions yielding CH + and C + fragment ions over a collision energy range from a few eV up to 100 eV. The total experimental uncertainties are about 12% at the maximum of the curves of cross sections (peak of the cross section, for the CH + channel). The obtained results suggest important roles played by pre-dissociation of bound states in the production of both the CH + andmore » C + fragment ions. Good agreement is found with other results reported for the CH + fragment, but some differences are found for the CD 2 + and C +.« less
  • Using a crossed electron-ion beams method, we measured absolute cross sections for electron-impact dissociation of the CD{sub 3}{sup +} molecular ions producing CD{sub 2}{sup +} fragment ions and CH{sub 3}{sup +} ions yielding CH{sup +} and C{sup +} fragment ions over a collision energy range from a few eV up to 100 eV. The total experimental uncertainties are about 12% at the maximum of the curves of cross sections (peak of the cross section for the CH{sup +} channel). The obtained results suggest important roles played by predissociation of bound states in the production of both the CH{sup +} andmore » C{sup +} fragment ions. Good agreement is found with other results reported for the CH{sup +} fragment, but some differences are found for the CD{sub 2}{sup +} and C{sup +} fragments.« less
  • Absolute cross sections for electron-impact dissociation of CH{sup +} producing C{sup +} fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 10% near the cross-section peak. Although the measured energy dependence agrees well with two sets of storage ring measurements, the magnitude of the present results lies about 15-25 % below the other results at the cross-section peak near 40 eV. Below 10 eV, the present data tend to exceed the storage ring data, consistent with the presence of excited states in the CH{sup +} ion beam. For energiesmore » above 29 eV, the cross sections should also include contributions from dissociative ionization, though no clear onset of this channel is evident in any of the three sets of measured data.« less