Identification of {sup 180}Tl {alpha} decay

With the use of a fragment mass analyzer, the {alpha} decay of {sup 180}Tl was identified in {sup 92}Mo bombardments of {sup 90}Zr. At least three {alpha} transitions were observed but on the basis of the data obtained it was not possible to conclude if they originate from one or more levels in {sup 180}Tl. In the same irradiations a new {alpha} group was also identified in {sup 179}Tl{sup m} decay. Based on energy and half-life systematics, it appears that {sup 179}Tl{sup m}, in contrast to the isomers in heavier odd-{ital A} Tl nuclei, is not the h{sub 9/2} intruder level but rather the h{sub 11/2} proton state. {copyright} {ital 1998} {ital The American Physical Society}