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.