Nuclear data sheets for A = 121

Abstract

The literature has been surveyed for data pertaining to nuclei in the mass chain A = 121. Well over 200 papers and communications were considered, and information for approximately 100 has been included. The cutoff date was the end of February 1971. The data for this mass chain are rather fragmentary. Few spin assignments are firm. The half-life of the 8-keV isomer in 121Sn is still very much in doubt. The characteristics of the levels in 121Sb are not yet well defined, but the enhanced E2 component of the 66-keV transition between the 0.57308 (1/2 +) and 0.50754 (3/2 +) levels may imply a large deformation. There seems to be building a cumulation of evidence throughout the mass region A ≈ 100–140 indicating the presence of such a deformation at about 500–1000 keV of excitation. The present compilation might serve as a basis for choosing definitive experiments that would augment our knowledge of nuclei in this mass chain.