Status of the AMoRE experiment to search for Neutrinoless Double Beta Decay of Mo-100

Abstract

The AMoRE (Advanced Mo-based Rare process Experiment) is an experimental search for neutrinoless double beta decay of \(^{100}\)Mo using enriched in \(^{100}\)Mo and depleted in \(^{48}\)Ca calcium molybdate (\(^{48\rm{depl}}\)Ca\(^{100}\)MoO\(_4\)) scintillating crystals at low temperature aiming to investigate the inverted hierarchy of the neutrino mass pattern. The AMoRE uses metallic magnetic calorimeter sensors to read out scintillation and phonon signals from the crystals at milli-Kelvin temperature, which provide an excellent energy resolution (~10 keV FWHM at 2615 keV) and very efficient particle discrimination to suppress background caused by U/Th contamination of the crystal scintillators and near materials. The AMoRE experiment is intended to reach zero-background level in the region of interest, near the energy of \(^{100}\)Mo double beta decay 3034 keV. Monte Carlo simulations using the GEANT4 code and measurements of radioactive contamination of the \(^{48\rm{depl}}\)Ca\(^{100}\)MoO\(_4\) crystal scintillators, detectors and shielding materials are in progress. Currently, the AMoRE pilot experiment with five \(^{48\rm{depl}}\)Ca\(^{100}\)MoO\(_4\) detectors (total mass ~1.5 kg) is running at the YangYang underground laboratory (Korea). The first phase of the AMoRE experiment, using ~5 kg of \(^{48\rm{depl}}\)Ca\(^{100}\)MoO\(_4\) detectors, is scheduled to start at the end of 2017. Preparations for the first phase experiment and R&D for the second phase experiment with ~200 kg of molybdate crystal scintillators is ongoing.