Performance evaluation in different environments of the MCP-PMT for the TOP counter in the Belle II experiment
Year: 2026
Type: article
Abstract: At the Belle II experiment, a Time-of-Propagation (TOP) counter is used for charged particle identification in the barrel region. The TOP counter employs micro-channel-plate photomultiplier tubes (MCP-PMTs), which have excellent time resolution. One of the issues for the TOP counter is the photocathode lifetime of the MCP-PMT. During the Belle II experiment, quantum efficiency (QE) was found to decrease more rapidly than expected from pre-installation lifetime tests. In these proceedings, we investigate the effect of environmental conditions on the QE degradation. Lifetime measurements at different temperatures showed no significant effect on the QE degradation. Afterpulse and lifetime measurements of the MCP-PMTs with and without a magnetic field revealed that the magnetic field affects the QE degradation and indicated a possible contribution from ions.
Author: Ryotaro Komori
Institution: Nagoya University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,620
Funders: National Science Foundation, U.S. Department of Energy, University of Victoria, Department of Atomic Energy, Government of India, Ministry of Education, Culture, Sports, Science and Technology, Javna Agencija za Raziskovalno Dejavnost RS, Istituto Nazionale di Fisica Nucleare, Japan Society for the Promotion of Science, Science and Engineering Research Board, Instituto Nazionale di Fisica Nucleare, Institut National de Physique Nucléaire et de Physique des Particules
Awards: G1509888190, G2226251677, G241279073, EXPERIMENTAL NEUTRINO PHYSICS, RESEARCH IN HIGH ENERGY PHYSICS, G326497735, Experimental Nuclear Physics and Fundamental Interactions at Indiana University, PARTICLE PHYSICS AT THE UNIVERSITY OF PITTSBURGH, G3890255932, Experimental Particle Physics, Probing New Physics with Tau-Lepton, INTENSITY FRONTIER STUDIES AT THE UNIVERSITY OF MISSISSIPPI, Advanced hadron identification methods for Belle II, Search for New Symmetry Violation in Leptons, G8081386760, Exploration of the particle physics frontier at the Super B-factory and cultivation o f young researchers, Evolution of Tau-lepton Physics, CP VIOLATION SEARCHES AND DISTRIBUTED COMPUTING DEVELOPMENT WITH THE BELLE II EXPERIMENT AT THE UNIVERSITY OF MISSISSIPPI AND BROOKHAVEN NATIONAL LAB, Investigation of the flavor anomaly problem by the world's highest luminosity accelerator experiment, RESEARCH IN PARTICLE THEORY AND EXPERIMENT AT THE UNIVERSITY OF CINCINNATI
OpenAlex ID: W7128914858