Impurity release and deuterium retention properties of a ferritic steel wall in JFT-2M

摘要

Impurity release and the deuterium retention properties of the low activation ferritic steel, which is a candidate material for a demo-reactor, have been studied in the JFT-2M and in the laboratory. In the case when the inside vacuum vessel wall is fully covered by ferritic steel plates, enhancement of the oxygen influx and the emission of iron ion lines were not observed. This means that the impurity release from the ferritic steel has no deleterious effect on JFT-2M. From irradiation experiments, the retained amount of deuterium in the sample with an oxide layer was one order of magnitude larger than that of the mechanically polished sample for the low fluence case. However it became comparable at the high fluence case, and was roughly the same as that of SUS-316L. Retained amount of deuterium in the sample exposed to JFT-2M plasmas was similar to that exposed to the deuterium ion beam. (C) 2004 Published by Elsevier B.V.