The impact of helium exposure on the PMTs of the SuperNEMO experiment
- NázevTitle
- The impact of helium exposure on the PMTs of the SuperNEMO experimentThe impact of helium exposure on the PMTs of the SuperNEMO experiment
- Druh výsledkuResult type
- Článek v časopiseJournal article
- AutořiAuthors
- X. Aguerre, A.S. Barabash, A. Basharina-Freshville, M. Bongrand, R. Hodák, F. Koňařík, T. Křižák, M. Macko, F. Mamedov, A. Mendl, V. Palušová, M. Petro, Y. Shitov, F. Šimkovic, I. Štekl
- DOIDOI
- 10.1088/1748-0221/20/06/P06018
- Časopis / citaceJournal / citation
- Journal of Instrumentation. 2025, 20(6), 1-19. ISSN 1748-0221.
- RokYear
- 2025
- JazykLanguage
- eng
- WoSWoS
- 001517223700001
- ScopusScopus
- 2-s2.0-105009626305
- RIVRIV
- RIV/68407700:21340/25:00384173!RIV26-MSM-21340___
- ProjektProject
- Laboratoire Souterrain de Modane - účast ČRLaboratoire Souterrain de Modane – participation of the Czech Republic
AbstraktAbstract
The performance of Hamamatsu 8” photomultiplier tubes (PMTs) of the type used in the SuperNEMO neutrinoless double-beta decay experiment (R5912-MOD), is investigated as a function of exposure to helium (He) gas. Two PMTs were monitored for over a year, one exposed to varying concentrations of He, and the other kept in standard atmospheric conditions as a control. Both PMTs were exposed to light signals generated by a 207Bi radioactive source coupled to a plastic scintillator, which provided consistent large input PMT signals similar to those that are typical of the SuperNEMO experiment. The energy resolution of PMT signals corresponding to 1 MeV energy scale determined from the 207Bi decay spectrum, shows a negligible degradation with He exposure; however the rate of after-pulsing shows a clear increase with He exposure, which is modelled and compared to diffusion theory. A method for reconstructing the partial pressure of He within the PMT and a method for determining the He breakdown point, are introduced. The implications for long-term SuperNEMO operations are briefly discussed.
The performance of Hamamatsu 8” photomultiplier tubes (PMTs) of the type used in the SuperNEMO neutrinoless double-beta decay experiment (R5912-MOD), is investigated as a function of exposure to helium (He) gas. Two PMTs were monitored for over a year, one exposed to varying concentrations of He, and the other kept in standard atmospheric conditions as a control. Both PMTs were exposed to light signals generated by a 207Bi radioactive source coupled to a plastic scintillator, which provided consistent large input PMT signals similar to those that are typical of the SuperNEMO experiment. The energy resolution of PMT signals corresponding to 1 MeV energy scale determined from the 207Bi decay spectrum, shows a negligible degradation with He exposure; however the rate of after-pulsing shows a clear increase with He exposure, which is modelled and compared to diffusion theory. A method for reconstructing the partial pressure of He within the PMT and a method for determining the He breakdown point, are introduced. The implications for long-term SuperNEMO operations are briefly discussed.