The re-emission of H and D, which had been implanted up to saturation at room temperature by means of 2keV D+ or 2.5keV H+ bombardment, was studied by using an elastic recoil detection technique. It was found that the decay rate of H implants which had been produced by D+ bombardment was higher, at low ion fluences, than that of D implants which had been produced by H+ bombardment. The former then became almost the same as the latter. The experimental decay curves were analyzed by fitting analytical solutions, to the mass balance equations, in which re-trapping, ion-induced de-trapping and molecular recombination were taken into account. The de-trapping cross-sections of H and D implants which were produced by D+ and H+ bombardment were determined to be equal to 3.3 x 10-18 and 2.5 x 10-18cm2, respectively. An isotope effect which was detected in the de-trapping cross-sections was considered in terms of 2 possible collision processes.

B.Tsuchiya, K.Morita: Journal of Nuclear Materials, 1995, 226[3], 293-301