Deuterium release rates in a-C : D-layers during oxygen attack

A laboratory produced very homogeneous a-C:D-layer (DIARC, 3.5 mu m of thic kness, D/C = 0.1) is oxidised in oxygen (0.3-20 kPa) at temperatures of 523 -723 K in order to generate D-releases; the results are used in development of a cleaning procedure of fusion reactor first walls from tritium. It is found, that the temperatures necessary for a continuous release are in the case of the DIARC specimen higher by about 100 K than for TEXTOR specimen e xamined earlier. Within the 50 K steps used, the burst-like D-release as ob served for TEXTOR specimen at lower temperatures was not found for DIARC. R aman and SIMS spectra for both kinds of specimen are reported. (C) 1999 Els evier Science B.V. All rights reserved.