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Title: Electron-impact dissociation of CH{sub 2}{sup +} ions: Measurement of CH{sup +} and C{sup +} fragment ions

Abstract

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 +} ion are also presented.

Authors:
; ; ;  [1];  [2]
  1. Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372 (United States)
  2. (Sweden)
Publication Date:
OSTI Identifier:
20982533
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.75.052715; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; CARBON IONS; CATIONS; CROSS SECTIONS; DISSOCIATION; ELECTRON BEAMS; EV RANGE; ION BEAMS; IONIZATION; MOLECULAR IONS; ORGANIC COMPOUNDS

Citation Formats

Vane, C. R., Bahati, E. M., Bannister, M. E., Thomas, R. D., and Department of Physics, Albanova, Stockholm University, SE106 91 Stockholm. Electron-impact dissociation of CH{sub 2}{sup +} ions: Measurement of CH{sup +} and C{sup +} fragment ions. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.052715.
Vane, C. R., Bahati, E. M., Bannister, M. E., Thomas, R. D., & Department of Physics, Albanova, Stockholm University, SE106 91 Stockholm. Electron-impact dissociation of CH{sub 2}{sup +} ions: Measurement of CH{sup +} and C{sup +} fragment ions. United States. doi:10.1103/PHYSREVA.75.052715.
Vane, C. R., Bahati, E. M., Bannister, M. E., Thomas, R. D., and Department of Physics, Albanova, Stockholm University, SE106 91 Stockholm. Tue . "Electron-impact dissociation of CH{sub 2}{sup +} ions: Measurement of CH{sup +} and C{sup +} fragment ions". United States. doi:10.1103/PHYSREVA.75.052715.
@article{osti_20982533,
title = {Electron-impact dissociation of CH{sub 2}{sup +} ions: Measurement of CH{sup +} and C{sup +} fragment ions},
author = {Vane, C. R. and Bahati, E. M. and Bannister, M. E. and Thomas, R. D. and Department of Physics, Albanova, Stockholm University, SE106 91 Stockholm},
abstractNote = {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 +} ion are also presented.},
doi = {10.1103/PHYSREVA.75.052715},
journal = {Physical Review. A},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • 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 aremore » 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