Deexcitation of the 662-keV State inBa137by the Internal Compton Effect

A double-decay process in which the transition energy is distributed between one photon and one $K$ conversion electron was investigated in the decay of the 662-keV state in ${}_{}{}^{137}{}_{}{}^{}\mathrm{Ba}$. For the energy interval of emitted photons from 50 to 150 keV, the result of $\frac{T_{K\gamma }}{T_K}=(2.2\mathrm{}\pm 0.2)\times {10}^{-3\mathrm{}}$ was obtained. The measured energy and angular distributions are compared with the Spruch-Goertzel theory in which the process is treated as the internal Compton effect. Some deviations from the theory are observed in both distributions. The contribution of nuclear intermediate states is negligible in the range of energies which was investigated.