Low Temperature CaMoO$_{4}$ Crystal Detectors for the AMoRE Project

The AMoRE (Advanced Mo-based Rare process Experiment) project is an international experiment to search for neutrinoless double beta decay of $^{100}$Mo. Excellent energy resolution and particle-type discrimination are essential to improve the experimental sensitivity in rare event search experiments of this type. Here we report performances of low temperature detectors composed of CaMoO$_{4}$ crystals and metallic magnetic calorimeters (MMCs). Both of heat (phonon) and light (photon) measurements were carried at tens of milli-Kelvin temperatures. The FWHM energy resolution was obtained to be 5-9 keV for environmental gamma ray peaks in the phonon channel. Clear separation (better than 15 $\sigma$) was found for alpha and electron events with heat/light ratio comparison. Pulse shape discrimination with phonon signal only was also successful with better than 15 $\sigma$ of discrimination power. Moreover, signal rise-time with the MMC sensors was faster than 1 ms. It may improve rejection ability for random coincidences of two neutrinos double beta decay events that is one of major background sources for the experiment.