Experimental system to search for induced depletion of $^{166m}$Ho

Known nuclear data indicate that incoming photons below 300 keV might cause an induced depletion of the 1200 year isomer of $^ {166}$Ho. This process would be identified by an excess of ground state activity after irradiation with bremsstrahlung or by excess activity in any excited state that was part of the depletion cascade. A unique sign of depletion in $^{166}$Ho would be radiation emitted near 136 keV from a level above the isomer, but part of the expected depletion cascade. A detection system has been developed using a gated fast inorganic scintillator to observe gamma rays after pulsed irradiation of an isomeric sample containing $^{166}$Ho using an electron linac.