Production of isomers by the cyclic activation method

The isomeric states formation cross sections for 14.8 MeV neutron reactions in Mg, Al, As, Y, In, Hf, Tl, Pb, and Bi were measured using the cyclic activation technique and a high resolution Ge(Li) detector. Isomeric activities originating from the various isotopes of lead and thallium were separated by proper choice of cyclic timing parameters and energy discrimination. Long lived isomeric and ground state activities were investigated through conventional activation method. The isomeric cross section ratios, sigma/sub m//sigma/sub g/ for six elements, were measured and compared to the theoretical predictions of the Huizenga-Vandenbosch method. The half-lives of short-lived activities were determined using a wide range time-to-pulse height converter and a multi-channel analyzer