Measurement of the Yield Ratio of the $^{122m,g}\text{Sb}$ Isomeric Pair Above the Giant Resonance

Abstract

The yield ratio of the high-spin state of $^{122m}\text{Sb} (8^{ - })$ and the low-spin state of $^{122g}\text{Sb} (2^{-})$ formed via the $^{123}\text{Sb}(\gamma, n)^{122m,g}\text{Sb}$  reaction has been measured as a function of the bremsstrahlung end-point energy in the range of 40-MeV to 60-MeV. Use was made of the activation technique in combination with high-resolution $\gamma$-ray spectrometry. The isomeric yield ratios for the $^{123}\text{Sb}(\gamma,n)^{122m,g}\text{Sb}$  reaction measured at 40-, 45-, 50-, 55-, and 60-MeV bremsstrahlung are $0.341\pm  0.022$, $0.362 \pm 0.020$, $0.374 \pm 0.021$, $0.371 \pm 0.021$, and $0.367 \pm 0.022$. According to our knowledge, the present results are the first measurement.