Luminescence and scintillation characterization of PbMoO₄ crystal for neutrinoless double beta decay search

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>A PbMoO<SUB>4</SUB> single crystal with optically good quality and crack free, bulk crystal is grown by the low thermal gradient Czochralski method. The luminescence and scintillation properties of the grown crystal are measured under the excitations by 4.4 eV UV, 662 keV γ, 5.5 MeV α, and β in the temperature range of 10–300 K. The light yield under UV and β excitations are found to enhance down to 10 K, however quenched below 50 K under γ and α excitations. The major luminescence and scintillation decay time constants are found to be 20 μs, 18 μs, and 28 μs, respectively, with 4.4 eV, 662 keV γ, and 5.5 MeV α excitations at 10 K. The thermally stimulated luminescence (TSL) glow curve measured after X-ray irradiation at 10 K, shows three overlapping peaks in the temperature range of 10–70 K. The TSL kinetic parameters such as trap depth (E) and frequency factor (s) are determined by using general order kinetics and found to be, 41.5 K (peak-1), 35 meV, 3.95 × 10<SUP>2</SUP> s<SUP>−1</SUP>, 51.1 K (peak-2), 121 meV, 4.31 × 10<SUP>10</SUP> s<SUP>−1</SUP>, and 56.8 K (peak-3), 123 meV, 3.32 × 10<SUP>9</SUP> s<SUP>−1</SUP>. The quenching of scintillation light yield under α and γ excitations at lower temperature is due to the self-trapping of electrons at (MoO<SUB>4</SUB>)<SUP>2-</SUP> molecular complex.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Luminescence, scintillation and TSL properties are studied in 10–300 K range. </LI> <LI> Scintillation light under α- and γ-rays excitation quenches below 50 K. </LI> <LI> Light yield enhances under UV and β-rays excitation down to 10 K. </LI> <LI> The major decay time becomes slower with decreasing the temperature. </LI> <LI> TSL kinetics parameters are calculated with general order kinetics. </LI> </UL> </P>