Identifying the induced depletion of $^{166m }$Ho

Current nuclear data indicates that incoming photons below 300 keV may allow for an induced depletion of the $^{166}$Ho isomer. Such photons will excite the nucleus of a sample of $^{166m}$Ho up to a higher state. From there, the nucleus could decay back to this first metastable state or take a separate decay path down to the ground state. While the first metastable state has a half-life of 1200 years, such an induced depletion would allow the nucleus to decay to its ground state in just fractions of a second. From there, further beta decay occurs on the order of about 24 hours. During the induced depletion cascade, a 136 keV gamma ray will be emitted from a level that has a 185 $\mu $s half-life and is above the initial isomer. A detection system has been designed to detect this unique photon as well as evidence of the 185 $\mu $s half-life; both are signals that the induced depletion has occurred. A cerium-doped lanthanum chloride (LaCl$_{3}$:Ce) scintillator coupled to a gated photomultiplier tube is used to observe gamma rays from the isomeric sample of $^{166}$Ho. Timing data of the unique photon will be recorded in between bremsstrahlung pulses from an electron linac. First results of this experiment will be discussed.