Physics & Astronomy ETDs

Publication Date



If the phenomenon of isomerism occurred in bromine nuclei, it would be of great help in elaborating the level schemes of these isotopes. The occurrence of isomerism in the odd isotopes of arsenic and rubidium, the nearest odd-Z neighbors to bromine, suggested similar behavior in bromine odd-Z isotopes. In this investigation, the pulsed-beam method was used to search for isomers. The procedure consisted of pulsing the beam of a Van de Graaff accelerator and counting any resulting activities during the time between beam pulses. After preliminary surveys during which natural bromine was bombarded with neutrons and natural selenium was bombarded with protons and deuterons, protons were used to bombard selenium targets enriched in selected isotopes. The spectra of the resulting activities were observed with a 100-channel analyzer and the half-lives of the activities of interest were measured with a 9-channel time-delay analyzer. The detectors of the gamma-ray activities consisted of thallium-activated sodium iodide crystals mounted on photomultipliers. From these measurements it was possible to conclude that there indeed were isomers in Br77, Br79 and Br81 as well as Br78. Some of the activities found had been previously reported but were not assigned to any particular bromine isotope.

Degree Name


Level of Degree


Department Name

Physics & Astronomy

First Committee Member (Chair)


Second Committee Member

Victor H. Regener

Third Committee Member

John Root Green



Document Type