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Title: Surface loss probability of atomic hydrogen for different electrode cover materials investigated in H₂-Ar low-pressure plasmas

In an inductively coupled H₂-Ar plasma at a total pressure of 1.5 Pa, the influence of the electrode cover material on selected line intensities of H, H₂, and Ar are determined by optical emission spectroscopy and actinometry for the electrode cover materials stainless steel, copper, tungsten, Macor{sup ®}, and aluminum. Hydrogen dissociation degrees for the considered conditions are determined experimentally from the measured emission intensity ratios. The surface loss probability β{sub H} of atomic hydrogen is correlated with the measured line intensities, and β{sub H} values are determined for the considered materials. Without the knowledge of the atomic hydrogen temperature, β{sub H} cannot be determined exactly. However, ratios of β{sub H} values for different surface materials are in first order approximation independent of the atomic hydrogen temperature. Our results show that β{sub H} of copper is equal to the value of stainless steel, β{sub H} of Macor{sup ®} and tungsten is about 2 times smaller and β{sub H} of aluminum about 5 times smaller compared with stainless steel. The latter ratio is in reasonable agreement with literature. The influence of the atomic hydrogen temperature T{sub H} on the absolute value is thoroughly discussed. For our assumption of T{sub H}=600 K,more » we determine a β{sub H} for stainless steel of 0.39±0.13.« less
Authors:
; ;  [1] ;  [2]
  1. Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, D-85748 Garching (Germany)
  2. Institute for Experimental and Applied Physics, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 11-19, D-24098 Kiel (Germany)
Publication Date:
OSTI Identifier:
22306244
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 1; Other Information: (c) 2014 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM; ATOMS; COPPER; DISSOCIATION; ELECTRODES; EMISSION; EMISSION SPECTROSCOPY; HYDROGEN; LOSSES; MOLECULES; PLASMA; PROBABILITY; STAINLESS STEELS; SURFACES; TUNGSTEN