Development and characterization of Li4Mo5O17 and Cs2Mo2O7 crystal for neutrinoless double beta decay experiment

by Jukyung Son (MS Candidate)

Wednesday May 25, 2016, 2:20 PM → 2:45 PM Asia/Seoul

119호 (제1과학관)

Recent result of neutrino oscillations show that neutrinos have mass. However, this result does not provide the absolute mass and the properties of neutrinos. To answer these unsolved questions, many collaborations carry out the neutrinoless double beta decay experiment. This study reports on the development and characterization of Li4Mo5O17 and Cs2Mo2O7 scintillation crystal for neutrinoless double beta decay experiment. 
If scintillation crystal containing the molybdenum (100Mo) emits the high light output, it could be a scintillator for neutrinoless double beta decay experiment. So, I grew the Li4Mo5O17 and Cs2Mo2O7 single crystals by using the Czochralski technique and report the new result of both crystals related to scintillation properties. The sintered powder is analyzed by X-ray diffraction and the Differential Scanning Calorimetry (DSC) measurement. These results give confirming the crystal phase of the synthesis temperature for crystal growth and the melting point of sintered powder. After growing the single crystal by the czochralski meathod, I prepared the sample for the luminescence properties experiment. In Cs2Mo2O7 case, I measured the temperature dependence of decay time and transmittance. From the transmittance result, I calculated the bandgap energy of Cs2Mo2O7. Besides, I compared the luminescence properties of Li4Mo5O17 and Cs2Mo2O7 with the Li2MoO4 crystal. The relative light output of Li4Mo5O17 and Cs2Mo2O7 crystal were measured at 10 K by comparing with Li2MoO4 crystal. The results show that Li4Mo5O17 and Cs2Mo2O7 crystal are able to use the neutrinoless double beta decay experiment.

Thesis Advisor: Prof. Hongjoo Kim