Comparison of Cf-252 thin-film sources prepared by evaporation or self-transfer

Thin-film sources containing Cf-252 were prepared by two techniques—evaporation and self-transfer—to determine whether sources prepared by simple evaporation work as well as sources prepared by self-transfer for alpha particle studies. The sources were analyzed by alpha and gamma spectroscopy. Results indicate that self-transfer sources exhibit less alpha energy straggling and alpha energy loss than evaporative sources. Fission fragments may also self-transfer, and sources made by self-transfer may need time to decay before reaching radioactive equilibrium.