Influence of hydrogen surface coverage on atomic particle reflection

Atomic reflection of deuterium on metal samples of nickel, palladium and type 304 stainless steel (SS-304) was observed by use of a permeation probe. The surface densities of deuterium on the sample materials, which were continuously irradiated by atomic deuterium particles, were measured by the nuclear reaction analysis (NRA). As a result, for each sample, the amount of reflected deuterium decreased with increasing the sample temperature and temperature dependence of the amount was very similar to that of the surface density of deuterium. This would be explained by the fact that atomic hydrogen is reflected as being atoms with a significant probability on hydrogen-covered surface but not reflected on hydrogen-free surface.