Speaker
Dr
Denys Poda
(Centre de Sciences Nucléaires et de Sciences de la Matière, CSNSM, 91405 Orsay, France and Institute for Nuclear Research, MSP 03680 Kyiv, Ukraine)
Description
The main purpose of the LUMINEU project (Luminescent Underground Molybdenum Investigation for NEUtrino mass and nature) is to elaborate a technology suitable for realization of a next-generation neutrinoless double-beta decay experiment to explore the inverted hierarchy region of the neutrino mass. This goal should be achieved through the development of low-temperature scintillating bolometers based on zinc molybdate (ZnMoO4) crystal scintillators enriched in 100Mo. We report a significant progress in producing of radiopure ZnMoO4 crystal scintillators with high bolometric performance. A dedicated molybdenum purification technique based on sublimation of molybdenum oxide and recrystallization from aqueous solutions of ammonium para-molybdate has been developed. The low-thermal-gradient Czochralski technique was utilized to produce high quality ZnMoO4 crystal scintillators. Radiopurity of two detectors with size D5x4 cm was tested in the EDELWEISS low background set-up at the Modane Underground Laboratory (France). The measurements demonstrate excellent energy resolution (FWHM ~ 4–5 keV in the wide energy range) and efficient discrimination between alpha and beta particles in the region of interest (~15*sigma above 2.6 MeV). Only 210Po (with activity on the level of ~1 mBq/kg) was detected in the analyzed alpha background. The activity of 228Th and 226Ra is below 5 uBq/kg. Test of a first 100Mo (99.5%) enriched ZnMoO4 crystal is in progress. The excellent performance of ZnMoO4-based scintillating bolometers, the high radiopurity of the crystals and the possible extension of the technology to a ton-scale experiment make the approach one of the most promising even able to probe the normal hierarchy of the neutrino mass pattern.
Primary author
Dr
Denys Poda
(Centre de Sciences Nucléaires et de Sciences de la Matière, CSNSM, 91405 Orsay, France and Institute for Nuclear Research, MSP 03680 Kyiv, Ukraine)
Co-authors
Collaboration EDELWEISS
(CEA Saclay, CSNSM Orsay, IPN Lyon, Neel Grenoble, KIT Karlsruhe, JINR Dubna, University of Oxford, University of Sheffield)
Collaboration LUMINEU
(CSNSM Orsay, IAS Orsay, ICMCB Bordeaux, CEA Saclay, INR Kyiv, NIIC Novosibirsk, KIP Heidelberg, INFN Milano Bicocca)
