In situ nuclear reaction analysis of D retention in undamaged and self-damaged tungsten under atomic D exposure

In situ deuterium depth profile measurements by nuclear reaction analysis (NRA) were performed on undamaged and neutron-like damaged W during D atom exposure at several sample temperatures. Damaged W was produced by high energy W-ion irradiation. In situ results of D retention after exposure termination are in good agreement with ex situ measurements for damaged W. In contrast, in situ NRA during D exposure on undamaged W showed significantly higher D retention than ex situ NRA measurement. It is also shown that this increased retention is lower at the location non-irradiated by the probing He-3 beam. These observations indicate that the D retention is influenced by secondary damage produced by the probing He-3 beam, however the dynamic retention could also partially contribute to the observed retention increase.