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Title: A collisional radiative model of hydrogen plasmas developed for diagnostic purposes of negative ion sources

A collisional radiative model of low-pressure hydrogen plasmas is elaborated and applied in optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The model accounts for the main processes determining both the population densities of the first ten states of the hydrogen atom and the densities of the positive hydrogen ions H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +}. In the calculations, the electron density and electron temperature are varied whereas the atomic and molecular temperatures are included as experimentally obtained external parameters. The ratio of the H{sub α} to H{sub β} line intensities is calculated from the numerical results for the excited state population densities, obtained as a solution of the set of the steady-state rate balance equations. The comparison of measured and theoretically obtained ratios of line intensities yields the values of the electron density and temperature as well as of the degree of dissociation, i.e., of the parameters which have a crucial role for the volume production of the negative ions.
Authors:
;  [1]
  1. Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria)
Publication Date:
OSTI Identifier:
22482932
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 2; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ANIONS; ELECTRON DENSITY; ELECTRON TEMPERATURE; EMISSION SPECTROSCOPY; EXCITED STATES; HYDROGEN IONS 1 PLUS; HYDROGEN IONS 2 PLUS; HYDROGEN IONS 3 PLUS; PLASMA