Design and performance of a high-pressure xenon gas TPC as a prototype for a large-scale neutrinoless double-beta decay search

• Published in: Progress of theoretical and experimental physics Vol. 2020; no. 3
• Main Authors: Ban, S, Hirose, M, Ichikawa, A K, Iwashita, Y, Kikawa, T, Minamino, A, Miuchi, K, Nakadaira, T, Nakajima, Y, Nakamura, K D, Nakamura, K Z, Nakaya, T, Obara, S, Sakashita, K, Sekiya, H, Sugashima, B, Tanaka, S, Ueshima, K, Yoshida, M
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.03.2020
• Subjects: Cosmic rays; Electric fields; Electrodes; Energy; Neutrinos; Physics; Rocket launches; Sensors; H20
• ISSN: 2050-3911; 2050-3911
• DOI: 10.1093/ptep/ptaa030

A high-pressure xenon gas time projection chamber, with a unique cellular readout structure based on electroluminescence, has been developed for a large-scale neutrinoless double-beta decay search. In order to evaluate the detector performance and validate its design, a 180 L size prototype is being constructed and its commissioning with partial detector has been performed. The obtained energy resolution at 4.0 bar is 1.73 $\pm$ 0.07% (FWHM) at 511 keV. The energy resolution at the $^{136}$Xe neutrinoless double-beta decay $Q$-value is estimated to be between 0.79 and 1.52% (FWHM) by extrapolation. Reconstructed event topologies show patterns peculiar to the track endpoint that can be used to distinguish $0\nu\beta\beta$ signals from gamma-ray backgrounds.