Measurement of isomeric yield ratios of 119m,gTe in the 60 and 70 MeV bremsstrahlung induced reaction of natTe

Abstract

The isomeric yield ratio i.e. the yield ratio of high to low spin state (IR=Yh/Yl) of 119m,gTe in the natTe(γ,xn) reaction at the bremsstrahlung end-point energies (Ee) of 60-, and 70-MeV were measured for the first time by using an off-line gamma-ray spectrometric technique. The bremsstrahlung energies were generated by impinging pulsed electron energies of 60-, and 70-MeV on a thin W-target at the Pohang Accelerator Laboratory. The present data at 60 and 70-MeV and similar literature data at other energies shows that the IR values of 119m,gTe increases sharply from 10 MeV to 18 MeV, which indicates the role of excitation energy. Thereafter it increases marginally due the opening of other reaction channels, which indicates the partition of excitation energy in different reaction channels.