HYDROGEN RETENTION OF B4C CONVERTED GRAPHITE

Citation
Y. Yamauchi et al., HYDROGEN RETENTION OF B4C CONVERTED GRAPHITE, Journal of nuclear materials, 222, 1995, pp. 851-855
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Nuclear Sciences & Tecnology","Mining & Mineral Processing","Material Science
ISSN journal
0022-3115
Volume
222
Year of publication
1995
Pages
851 - 855
Database
ISI
SICI code
0022-3115(1995)222:<851:HROBCG>2.0.ZU;2-S
Abstract
The hydrogen retention of B4C converted graphite was investigated by u sing ECR ion irradiation apparatus. The retention properties were exam ined by a technique of thermal desorption spectroscopy (TDS) after the hydrogen ion irradiation. The H-2 desorption peaks appeared both at 3 50 and 700 degrees C. The former peak was regarded as the detrapping f rom B-H bondings, and the latter from C-H bondings in the B4C layer. T he CH4 desorption peaks appeared both at 250 and 700 degrees C. Compar ed with the case of graphite, the hydrogen retention of B4C rapidly de creased with the temperature, since the detrapping of B-H bondings occ urred around at 300 degrees C. The total amount of trapped hydrogens i n the B4C was 1.5 times larger than that of the graphite. The activati on energies of H-2 and CH4 desorptions of the B4C were considerably sm aller than those of the graphite. The hydrogen retention of the B4C wa s largely reduced by the He+ ion bombardment after the hydrogen ion ir radiation. In particular, the reduction ratio for the hydrogens trappe d by boron was observed to be large.