Deuterium retention in tungsten and molybdenum

Trapping of D atoms implanted in W and Mo single crystals was investigated in connection with the implantation-induced defects by using ion beam analysis techniques. The amount of the retained D atoms near the surface layer of the W crystal was higher than of the Mo crystal at a temperature range between 300 and 650 K. Depth profile studies of the retained D atoms and defects indicated that trapping of D atoms implanted in the W and the Mo crystal was associated with lattice distortion due to implantation-induced extended defects such as interstitial loops. The D atoms implanted in the W crystal were found to be located near the tetrahedral interstitial site, both in the implant surface layer and in the greater depth where few displacements were expected to be created by collisions.