Scintillation light and phonon measurement based on Ir/Au-thermometers.

With the simultaneous measurement of the temperature signal of a CaWO[sub 4] absorber crystal and the scintillation light, it is possible to reject the gamma and electron background in the search for dark matter particles. We report on an alternative new light detector design for the CRESST experiment. For the light detector we use iridium/gold phase transition thermometers with a special circular structure and an Al phonon collector on a silicon substrate. With this detector an energy threshold of 22.3 eV on a 5σ level was achieved. The light detector was tested in coincidence with a phonon measurement of a 300 g CaWO[sub 4] crystal. The phonons from the CaWO[sub 4] crystal were measured with an Ir/Au thermometer with a transition temperature of 32 mK. [ABSTRACT FROM AUTHOR]