Luminescence and Scintillation Characterization of Sodium-Based Tungstate (Na2W2O7) Crystal for Dark Matter Search

• Published in: IEEE transactions on nuclear science Vol. 70; no. 7; pp. 1349 - 1356
• Main Authors: Pandey, Indra Raj, Daniel, D. Joseph, Cheon, Jongkyu, Kim, Hongjoo, Kim, Yeongduk, Lee, Moo Hyun, Truc, Lam Tan
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Calcium compounds; Compounds; Cryogenics; Crystal growth; Crystals; Czochralski method; Dark matter; Decay time; Excitation; kinetic parameters; Light emitting diodes; Luminescence; luminescence and scintillation properties; Na2W2O7 single crystal; Ocean temperature; Platinum; Powders; Room temperature; Scintillation; Single crystals; Strontium; Strontium 90; Strontium radioisotopes; Temperature; Temperature dependence; Thermoluminescence; thermoluminescence (TL) study; X ray sources
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2023.3280497

A Na 2 W 2 O 7 single crystal was grown with a conventional Czochralski technique in a platinum crucible. A solid-state reaction method was used for the preparation of the polycrystalline compound. Temperature-dependent luminescence and scintillation properties of the crystal were studied under the excitation with a 280 nm light-emitting diode (LED) source, an X-ray source, and a 90 Sr (beta) source. At different temperatures (from 300 to 10 K), an as-grown crystal's luminescence and scintillation light output was compared with a CaMoO 4 crystal. Although the light output of Na 2 W 2 O 7 crystal at room temperature is lower than CaMoO 4 crystal, at 10 K, it is almost comparable. Compared to room temperature, the crystal's luminescence and scintillation light output at 10 K were increased by <inline-formula> <tex-math notation="LaTeX">\sim </tex-math></inline-formula>17 and <inline-formula> <tex-math notation="LaTeX">\sim </tex-math></inline-formula>14 fold, respectively. The decay time of the crystal was studied between 300 and 10 K using a 280 nm LED excitation source, and it varies from <inline-formula> <tex-math notation="LaTeX">3 \mu \text{s} </tex-math></inline-formula> (300 K) to <inline-formula> <tex-math notation="LaTeX">\sim 94 \mu \text{s} </tex-math></inline-formula> (10 K). A thermoluminescence (TL) study was carried out between 10 and 550 K. The kinetic parameters of the TL peaks are calculated with various standard methods. The current result suggests that the studied crystal has good potential as a cryogenic detector for dark matter search experiments in the near future.