DYNAMIC BEHAVIOR OF HYDROGEN-ATOMS WITH A BORONIZED WALL

Citation
K. Tsuzuki et al., DYNAMIC BEHAVIOR OF HYDROGEN-ATOMS WITH A BORONIZED WALL, Journal of nuclear materials, 256(2-3), 1998, pp. 166-179
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Nuclear Sciences & Tecnology","Mining & Mineral Processing","Material Science
ISSN journal
0022-3115
Volume
256
Issue
2-3
Year of publication
1998
Pages
166 - 179
Database
ISI
SICI code
0022-3115(1998)256:2-3<166:DBOHWA>2.0.ZU;2-G
Abstract
Dynamic behavior of hydrogen atoms in boron films, which is one of can didate materials of the first wall of fusion devices, has been studied . Hydrogen absorption behavior was investigated with a glow discharge in hydrogen. After a strong absorption in the beginning of the dischar ge, hydrogen atoms were slowly and continuously absorbed for 10 h with out saturation. The slow absorption is due to deeper migration of hydr ogen atoms into the film, enhanced by the ion bombardment. A helium gl ow discharge causes both ion induced desorption and the deeper migrati on, and thus, hydrogen atoms are accumulated in the film when the H-2 and He discharges are repeated alternately. Most of the retained hydro gen atoms were released by heating up to 400 degrees C. A calculation result based on a simple model was compared with the experimental resu lts. A recombination coefficient was obtained from the analysis of the experimental transient release of the H atoms just after the H-2 disc harge. The time behavior at the initial phase of the He discharge was reproduced fairly well with use of a smaller cross-section for the He ion induced detrapping than that for H-2(+). (C) 1998 Elsevier Scienc e B.V. All rights reserved.