Summary. During the past year the work carried out in this program has included experiments on the x-ray output produced by the separated fission product beta sources, the interpretation of such experiments for the effective design of high level secondary x-ray sources, and the design and testing of prototype sources of secondary radiation for specific industrial applications. In this report results of work carried out during the past fours months are reported: (1) analysis of beta-excited x-rays; (2) performance of Kr85 prototype x-ray source; and (3) design of high level Pm147 x-ray sources.