Scintillation Properties and Internal Background Study of $^{40}$Ca$^{100}$MoO$_{4}$ Crystal Scintillators for Neutrino-Less Double Beta Decay Search

Abstract

Scintillation properties and radioactive contamination of calcium molybdate scintillating crystals depleted in Ca and enriched in Mo ( Ca MoO ) have been studied to prepare a Mo-based neutrinoless double beta decay experiment. The prospects of a neutrinoless double beta decay experiment using Ca MoO crystals are discussed.

Radiopure tungstate and molybdate crystal scintillators for double beta decay experiments

“…Calcium molybdate crystal scintillators enriched in molybdenum 100, from calcium depleted in calcium 48 were developed for the AMoRE 2β experiment [39,101] aiming at search for 0ν2β − decay of 100 Mo by using cryogenic scintillating bolometers. Using of the depleted calcium is requested to avoid contribution of the 2ν2β − events of 48 Ca (Q 2β = 4268 keV) to the ROI of the AMoRE experiment (energy of the expected 0ν2β − peak of 100 Mo is Q 2β = 3034 keV).…”

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

“…Radioactive contamination of the CMO crystals by 238 U, 235 U, 232 Th, and their daughters was measured by a 4π gamma measurement system, composed of 14 CsI:Tl scintillating crystals, at the Y2L [5]. In addition, optical and scintillation properties such as the attenuation length, maximum emission wavelength, the absolute light yield of CMO crystals have been measured in a wide temperature interval 7K -300K [6,7,8].…”

Development of Crystal Scintillators From Enriched Isotopes for Double $\beta$ Decay Experiments

“…is also one of the most promising candidates to explore neutrino mass in the decay experiments thanks to very promising theoretical estimations of the decay [74]- [76]. Calcium molybdate crystal scintillators enriched in and depleted in were developed for the first time by AMoRE collaboration with the aim to construct a large scale experiment to search for decay of [33], [50], [77], [78]. Depletion in is necessary to suppress the irremovable background caused by decay of (decay energy [73] and isotopic abundance in natural calcium [61]).…”

“…to [34], [35], [54], [55] and [53]. Nevertheless the collaboration has reached a certain success in purification of calcium and molybdenum, as well as in growing of high quality large volume crystal samples to be used as cryogenic scintillating bolometers [33] (see also Table III). Development of a protocol to produce high quality crystal scintillators with low enough level of radioactive contamination by U/Th is in progress [33], [50].…”