Characterization of light production and transport in tellurium dioxide crystals

Journal Article · 23 October 2019 · Journal of Instrumentation

DOI: https://doi.org/10.1088/1748-0221/14/10/P10032 · OSTI ID:1603532

Huang, R. G. ^[1]; Benato, G. ^[1]; Caravaca, J. ^[1]; Kolomensky, Yu. G. ^[1]; Land, B. J. ^[1]; Gann, G. D. Orebi ^[1]; Schmidt, B. ^[2]

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1. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Simultaneous measurement of phonon and light signatures is an effective way to reduce the backgrounds and increase the sensitivity of CUPID, a next-generation bolometric neutrinoless double-beta decay ($$0\nu\beta\beta$$) experiment. Light emission in tellurium dioxide (TeO$$_2$$) crystals, one of the candidate materials for CUPID, is dominated by faint Cherenkov radiation, and the high refractive index of TeO$$_2$$ complicates light collection. Positive identification of $$0\nu\beta\beta$$ events therefore requires high-sensitivity light detectors and careful optimization of light transport. A detailed microphysical understanding of the optical properties of TeO$$_2$$ crystals is essential for such optimization. We present a set of quantitative measurements of light production and transport in a cubic TeO$$_2$$ crystal, verified with a complete optical model and calibrated against a UVT acrylic standard. We measure the optical surface properties of the crystal, and set stringent limits on the amount of room-temperature scintillation in TeO$$_2$$ for $$\beta$$ and $$\alpha$$ particles of 5.3 and 8 photons / MeV, respectively, at 90% confidence. Finally, the techniques described here can be used to optimize and verify the particle identification capabilities of CUPID.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-05CH11231; FG02-00ER41138; SC0018987
• OSTI ID: 1603532
• Journal Information: Journal of Instrumentation, Vol. 14, Issue 10; ISSN 1748-0221
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English