The permeation of H under He-ion bombardment was examined. The up-stream surface of a V membrane was exposed to H gas at 673K and 640Pa, while the down-stream surface was bombarded with 5keV He ions. No appreciable variation in the permeation rate was observed in the initial stages of irradiation. The permeation rate began to decrease at a He-ion dose of 1021/m2, during further bombardment. In this region, the permeation rate dropped immediately upon interrupting bombardment and increased sharply upon resumption. These results could be successfully explained in terms of a model in which He bubbles acted as trapping sites for H, and in which de-trapping was enhanced by bombardment.

Permeation of Hydrogen through Vanadium under Helium Ion Irradiation. Y.Hatano, Y.Nanjo, R.Hayakawa, K.Watanabe: Journal of Nuclear Materials, 2000, 283-287, 868-71