Hard amorphous films of D-doped material were deposited by means of radio-frequency glow discharge in CD4, and were bombarded with 40keV 3He+ ions at temperatures of between 100K and ambient. The content of trapped He, and the degree of D loss, were determined by using nuclear reaction analysis with 0.5MeV D+ and 1MeV 3He+ beams. Transient He retention was detected only at temperatures below 200K. When a critical fluence (which depended upon the temperature and the ion flux) was exceeded, He out-diffusion was observed and was attributed to the formation of diffusion channels by radiation damage. The D depletion which was caused by He bombardment at temperatures below 200K was thought to be related to He out-diffusion, but was otherwise independent of He-trapping.

D.Boutard, I.Gudowska, B.M.U.Scherzer, W.Möller: Journal of Applied Physics, 1990, 68[5], 2068-72