ISOMER-RATIOS IN ANTIMONY AND TELLURIUM ISOTOPES

Isomer ratios have been measured in Sb and Te isotopes prepared in the 115In( alpha ,n), 115In( alpha ,3n), 118,120,122,124Sn( alpha ,pn), and 120Sn( alpha ,3n) reactions, using a range of bombarding energies between 16.6 and 38.4 MeV. In most of the product nuclei the isomer ratios are smaller than the predictions of the sharp cut-off model, showing that the isomer is less than 100% efficient in trapping high-spin products. The variation of isomer ratio with bombarding energy is described by a simple expression for the trapping efficiency.