Search for alpha-decay of Th-229m produced from Ac-229 beta-decay following Th-232(gamma, p2n) reaction

摘要

We produced Th-229 in the nuclear reaction Th-232(gamma, p2n)Ac-229, followed by disintegration to Th-229m,Th-g. The Th-229m alpha-decay was searched for. Alpha-particle events of energy between 4.93 MeV and 5.05 MeV were observed in the separated thorium sample of beta-decay products from an actinium source highly purified from the Th-232 + gamma reaction products. The energies of the a-particles coincide with those expected for Th-229m.