Speaker
Description
The AMoRE (Advanced Molybdenum based Rare process Experiment) project is an experiment aiming for searching the neutrinoless double beta decay of $^{100}$Mo. The planned technique is a combination of 200 kg of X-Molybdates (~100 kg of $^{100}$Mo and X candidates are Ca, Li, Na, and Pb.) scintillating crystals as an absorber and metallic magnetic calorimeter (MMC) sensor as a heat and light signal detector at mK temperatures.
1.8 kg of $^{40}$Ca$^{100}$MoO$_{4}$ ($^{48}$Ca depleted, $^{100}$Mo enriched) scintillating crystals are currently installed in the AMoRE-pilot experiment and two candidate crystals, Na$_{2}$MoO$_{7}$ and Li$_{2}$MoO$_{4}$, have been being investigated for the large scale experiment with their easiness in crystal growth and internal background control.
The AMoRE phase-II with 200 kg of molybdate crystals aims to reach the range of the inverted neutrino mass hierarchy for an effective Majorana neutrino mass sensitivity of 10~30 meV which can be obtained by a zero background (~1 x 10$^{-4}$ count/keV/kg/y in total) experiment. In order to obtain the mass sensitivity, the internal background levels of the crystal are estimated to be less than 15 $\mu$Bq/kg for $^{226}$Ra and 1.5 $\mu$Bq/kg for $^{228}$Th.
We will report the current status of the R&D of molybdate crystals for the AMoRE phase-II.
