New isomeric transitions of short life in gold, mercury and thallium.

The work described in this thesis is concerned with the measurement of gamma-ray energies with a NaI scintillation spectrometer and thereby, the identification of new isomers produced in gold, mercury and thallium by proton bombardment in the McGill cyclotron. Soon after Breckon and Martin had set up their equipment for the study of short-lived radioactivities, survey experiments indicated unknown activities in several elements under proton bombardment. When gold or platinum was irradiated at increasing energies, the period, which at low energies was of the order of 7 seconds, seemed to become shorter. However, the results of this preliminary experiment were considered inconclusive due to trouble with the equipment used