nEXO is a proposed tonne-scale neutrinoless double beta decay (0νββ) experiment using liquid 136Xe (LXe) in a Time Projection Chamber (TPC) to read out ionization and scintillation signals. Between the field cage and the LXe vessel, a layer of LXe (“skin” LXe) is present, where no ionization signal is collected. Only scintillation photons are detected, owing to the lack of optical barrier around the field cage. In this work, we show that the light originating in the skin LXe region can be used to improve background discrimination by 5% over previous published estimates. This improvement comes from two elements. First, a fraction of the γ-ray background is removed by identifying light from interactions with an energy deposition in the skin LXe. Second, background from 222Rn dissolved in the skin LXe can be efficiently rejected by tagging the α decay in the 214Bi-214Po chain in the skin LXe.
|Journal||Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|State||Published - Jun 1 2021|
Bibliographical noteFunding Information:
Support for nEXO comes from the Office of Nuclear Physics of the Department of Energy and NSF in the United States, from NSERC , CFI , FRQNT , NRC , and the McDonald Institute (CFREF) in Canada, from The Institute for Basic Science, Center for Underground Physics, Republic of Korea , from RFBR ( 18-02-00550 ) in Russia, and from CAS and NSFC in China. LLNL-JRNL-814563.
© 2021 Elsevier B.V.
- Liquid xenon detectors
- Monte Carlo methods
- Neutrinoless double beta decay
- Time-projection chambers
ASJC Scopus subject areas
- Nuclear and High Energy Physics