Investigation of voltage amplification of thermal spectra ('Luke effect') in a low temperature calorimetric detector

It was proposed by Luke that the energy resolution and threshold of a semiconducting ionization detector should be improved by low temperature calorimetric measurement of the heat generated during the collection of the charge by an applied electric field. We present results showing the thermal response of a silicon ionization detector to a 57Co photon source. Amplification of the thermal signals is demonstrated, and the energy sensitivity is found to increase linearly with applied voltage, with a slope consistent with theoretical expectation. (orig.)