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Title: Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma

Abstract

Low pressure H{sub 2} discharges have been used for some time as sources of H{sup {minus}} ions. These discharges contain many different species of particles which interact with each other and with the walls of the discharge chamber. Models exist that predict the populations of the various species for given macroscopic discharge parameters. However, many of the cross sections and wall catalyzation coefficients are unknown or somewhat uncertain. Therefore, it is of interest to measure the populations of as many of these species as possible, in order to determine the validity of the models. These models predict that H{sup {minus}} is created predominantly by the two-step process of vibrational excitation of hydrogen molecules followed by dissociative attachment of slow electrons to these vibrationally-excited hydrogen molecules. Many different collisional processes must be included in the models to explain the dependence of the various populations upon macroscopic parameters. This work presents results of spectroscopic measurements of the density and translational temperature of hydrogen atoms and of specific rotationally- and vibrationally-excited states of electronic ground-state H{sub 2}, in a discharge optimized for H{sup {minus}} production, as well as conventional measurements of the various charged species within the plasma. The spectroscopic measurements are performedmore » directly by narrowband, single-photon absorption in the vacuum ultraviolet.« less

Authors:
Publication Date:
Research Org.:
Lawrence Berkeley Lab., CA (USA)
Sponsoring Org.:
USDOE; USDOE, Washington, DC (USA)
OSTI Identifier:
5836451
Report Number(s):
LBL-30541
ON: DE91011879
DOE Contract Number:
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; HYDROGEN; ABSORPTION SPECTROSCOPY; DISSOCIATION; EXPERIMENTAL DATA; HYDROGEN IONS 1 MINUS; HYSTERESIS; ION SOURCES; MOLECULES; ULTRAVIOLET SPECTRA; VIBRATIONAL STATES; ANIONS; CHARGED PARTICLES; DATA; ELEMENTS; ENERGY LEVELS; EXCITED STATES; HYDROGEN IONS; INFORMATION; IONS; NONMETALS; NUMERICAL DATA; SPECTRA; SPECTROSCOPY; 640302* - Atomic, Molecular & Chemical Physics- Atomic & Molecular Properties & Theory

Citation Formats

Stutzin, G.C. Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma. United States: N. p., 1990. Web. doi:10.2172/5836451.
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Stutzin, G.C. Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma. United States. doi:10.2172/5836451.
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Stutzin, G.C. Wed . "Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma". United States. doi:10.2172/5836451. https://www.osti.gov/servlets/purl/5836451.
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@article{osti_5836451,
title = {Spectroscopic measurement of H(1S) and H sub 2 (v double prime ,J double prime ) in an H sup minus ion source plasma},
author = {Stutzin, G.C.},
abstractNote = {Low pressure H{sub 2} discharges have been used for some time as sources of H{sup {minus}} ions. These discharges contain many different species of particles which interact with each other and with the walls of the discharge chamber. Models exist that predict the populations of the various species for given macroscopic discharge parameters. However, many of the cross sections and wall catalyzation coefficients are unknown or somewhat uncertain. Therefore, it is of interest to measure the populations of as many of these species as possible, in order to determine the validity of the models. These models predict that H{sup {minus}} is created predominantly by the two-step process of vibrational excitation of hydrogen molecules followed by dissociative attachment of slow electrons to these vibrationally-excited hydrogen molecules. Many different collisional processes must be included in the models to explain the dependence of the various populations upon macroscopic parameters. This work presents results of spectroscopic measurements of the density and translational temperature of hydrogen atoms and of specific rotationally- and vibrationally-excited states of electronic ground-state H{sub 2}, in a discharge optimized for H{sup {minus}} production, as well as conventional measurements of the various charged species within the plasma. The spectroscopic measurements are performed directly by narrowband, single-photon absorption in the vacuum ultraviolet.},
doi = {10.2172/5836451},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Aug 01 00:00:00 EDT 1990},
month = {Wed Aug 01 00:00:00 EDT 1990}
}
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Technical Report:
View Technical Report (3.13 MB)
DOI:  10.2172/5836451
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