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Title: Electronic excitation in collisions of H sub 2 sup + on He

Abstract

{ital Ab} {ital initio} cross sections have been calculated for electronic excitation resulting from single collisions in the keV energy range between H{sub 2}{sup +} initially in the ground electronic and vibrational state incident on He targets. These collisional excitation studies are based on {ital ab} {ital initio} calculations of the three lowest adiabatic states of the (HeH{sub 2}){sup +} quasimolecular system and {ital ab} {ital initio} calculations of the nonadiabatic gradient coupling matrix elements between these three adiabatic states. With use of straight-line trajectories in the classical trajectory approximation, cross sections have been obtained for (1) charge exchange into the ground state of He and (2) collisional dissociation via electronic excitation 1{sigma}{sub {ital g}}{r arrow}1{sigma}{sub {ital u}} of the H{sub 2}{sup +} projectile. Furthermore, with a knowledge of the diabatic structure of the (HeH{sub 2}){sup +} energy levels, (3) the sum of the cross sections for Rydberg excitation of the He target or Rydberg excitation of the H{sub 2}{sup +} projectile or charge exchange into the repulsive state of H{sub 2} was also obtained. The calculated cross sections are in reasonable agreement with available experimentally measured cross sections. The energy thresholds for these cross sections are found to bemore » determined by excitation at level crossings between the ground electronic state and the H{sub 2}{sup +}(1{sigma}{sub {ital u}})+He(1{ital s}{sup 2}) at {ital R}{approx equal}1.2 a.u. and the H{sub 2}{sup +}(1{sigma}{sub {ital g}})+He(1{ital s},2{ital l}) at {ital R}{approx equal}0.7 a.u.« less

Authors:
;  [1]
  1. Department of Physics, The University of Connecticut, Storrs, CT (USA)
Publication Date:
OSTI Identifier:
6144820
Resource Type:
Journal Article
Journal Name:
Physical Review, A; (USA)
Additional Journal Information:
Journal Volume: 42:11; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; HELIUM; ION-ATOM COLLISIONS; HYDROGEN IONS 2 PLUS; CHARGE EXCHANGE; CROSS SECTIONS; DISSOCIATION; EXCITATION; KEV RANGE; ATOM COLLISIONS; CATIONS; CHARGED PARTICLES; COLLISIONS; ELEMENTS; ENERGY RANGE; ENERGY-LEVEL TRANSITIONS; FLUIDS; GASES; HYDROGEN IONS; ION COLLISIONS; IONS; MOLECULAR IONS; NONMETALS; RARE GASES; 640304* - Atomic, Molecular & Chemical Physics- Collision Phenomena

Citation Formats

Furlan, R J, and Russek, A. Electronic excitation in collisions of H sub 2 sup + on He. United States: N. p., 1990. Web. doi:10.1103/PhysRevA.42.6436.
Furlan, R J, & Russek, A. Electronic excitation in collisions of H sub 2 sup + on He. United States. https://doi.org/10.1103/PhysRevA.42.6436
Furlan, R J, and Russek, A. 1990. "Electronic excitation in collisions of H sub 2 sup + on He". United States. https://doi.org/10.1103/PhysRevA.42.6436.
@article{osti_6144820,
title = {Electronic excitation in collisions of H sub 2 sup + on He},
author = {Furlan, R J and Russek, A},
abstractNote = {{ital Ab} {ital initio} cross sections have been calculated for electronic excitation resulting from single collisions in the keV energy range between H{sub 2}{sup +} initially in the ground electronic and vibrational state incident on He targets. These collisional excitation studies are based on {ital ab} {ital initio} calculations of the three lowest adiabatic states of the (HeH{sub 2}){sup +} quasimolecular system and {ital ab} {ital initio} calculations of the nonadiabatic gradient coupling matrix elements between these three adiabatic states. With use of straight-line trajectories in the classical trajectory approximation, cross sections have been obtained for (1) charge exchange into the ground state of He and (2) collisional dissociation via electronic excitation 1{sigma}{sub {ital g}}{r arrow}1{sigma}{sub {ital u}} of the H{sub 2}{sup +} projectile. Furthermore, with a knowledge of the diabatic structure of the (HeH{sub 2}){sup +} energy levels, (3) the sum of the cross sections for Rydberg excitation of the He target or Rydberg excitation of the H{sub 2}{sup +} projectile or charge exchange into the repulsive state of H{sub 2} was also obtained. The calculated cross sections are in reasonable agreement with available experimentally measured cross sections. The energy thresholds for these cross sections are found to be determined by excitation at level crossings between the ground electronic state and the H{sub 2}{sup +}(1{sigma}{sub {ital u}})+He(1{ital s}{sup 2}) at {ital R}{approx equal}1.2 a.u. and the H{sub 2}{sup +}(1{sigma}{sub {ital g}})+He(1{ital s},2{ital l}) at {ital R}{approx equal}0.7 a.u.},
doi = {10.1103/PhysRevA.42.6436},
url = {https://www.osti.gov/biblio/6144820}, journal = {Physical Review, A; (USA)},
issn = {1050-2947},
number = ,
volume = 42:11,
place = {United States},
year = {1990},
month = {12}
}