File:Masterarbeit Felix Ahrens.pdf

Scintillator based 0nu beta beta decay searches allow for an efficient background rejection due to particle discrimination. The light yield, that is the ratio of the light output and of the heat output of the scintillating crystal, depends on the mass of the interacting particle. In that way measured events due to alpha particles, for instance, can be easily discarded with respect to the electrons. Therefore, a simultaneous measurement of the heat channel and the light channel of the crystal is necessary. In order to obtain a large signal size and a low noise level, the set-up should be cooled to millikelvin temperatures, for which reason low temperature detectors are required. For the experiments AMoRE and LUMINEU, which apply this method for the 0nu beta beta search in the molybdenum isotope Mo-100, an integrated photon and phonon detector, which is based on the working principle of metallic magnetic calorimeters (MMCs), has been developed and microfabricated during this thesis. Simulations on the detector performance have been carried out, which predict an energy resolution of E_FWHM < 10 eV, a signal rise time of tau_0 < 50 µs and a signal decay time of tau_1 < 10 ms for the photon detector, while for the phonon detector E_FWHM < 100 eV, tau_0 < 200 µs and tau_1 < 10 ms are predicted. An advantage of the integrated detector design is the reduced amount of material in the vicinity of the crystal, which could contribute to the background.