SUMMARY
The yield ratio of the high-spin state of 122mSb(8-)^{122m}\text{Sb} (8^{ - }) and the low-spin state of 122gSb(2-)^{122g}\text{Sb} (2^{-}) formed via the 123Sb(?,n)122m,gSb^{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 123Sb(?,n)122m,gSb^{123}\text{Sb}(\gamma,n)^{122m,g}\text{Sb} reaction measured at 40-, 45-, 50-, 55-, and 60-MeV bremsstrahlung are 0.341±0.0220.341\pm 0.022, 0.362±0.0200.362 \pm 0.020, 0.374±0.0210.374 \pm 0.021, 0.371±0.0210.371 \pm 0.021, and 0.367±0.022 0.367 \pm 0.022. According to our knowledge, the present results are the first measurement.