Dissociative attachment to vibrationally excited H{sub 2} molecules as the principal mechanism for H{sup {minus}} formation in hydrogen discharges

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Bulletin of the American Physical Society

OSTI ID:67895

Hiskes, J R ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

Several mechanisms have been proposed for H{sup {minus}} formation in a hydrogen discharge. The lack of essential theor. and exp. data has made a specific identification difficult since both vibrational distributions and negative ion densities must be known for a modelling comparison with experiment. Henshuistra et. al. report both H{sub 2}(v) and H{sup {minus}} concentration observed in a medium density discharge. Principal excitation processes included in this analysis are thermal resonant and fast electron excitation throughout the full vibrational matrix and molecular-ion surface recombination. Principal de-excitation include b{sup 3}{Sigma}{sub {mu}}(v) and fast-electron excitation and ionization, H{sub 2}(v) surface and V-T relaxation. H{sup {minus}} equilibrium forms via DA, detachment and recomb. processes. Variations in modelling results are expressed in terms of both rate processes and exp. density uncertainties. The solutions presented here represent the first successful comparison of both H{sub 2}(v) and H{sup {minus}} concentrations with exp. and confirm the H{sub 2}(v) - DA process as the principal mechanism.

• OSTI ID: 67895
• Report Number(s): CONF-9310400--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 13 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DISSOCIATION
ELECTRON ATTACHMENT
ELECTRON-MOLECULE COLLISIONS
HYDROGEN
HYDROGEN IONS 1 MINUS