Isomers with half-lives greater than approximately 5 μsec were sought between the 180-cps, 1-μsec x-ray pulses of a 22-Mev betatron. The following new activities were observed:

Excitation functions and cross sections for the production of the above isomers are also given for some cases. The properties of all the isomers investigated are summarizes in this paper. Additional results include improved values for half-lives and gamma-ray energies, plus some measurements on production thresholds, excitation functions, and cross sections for the isomers listed in a previous paper.

• Received 1 April 1958

DOI:https://doi.org/10.1103/PhysRev.112.1958