ニュートリノ・核子崩壊物理を探る次世代のハイパーカミオカンデ実験で重要な大口径光電子増倍管の実証測定と、検出精度を高める較正装置の研究を行った。ここで用いる新型光電子増倍管の光検出性能は従来より2倍以上に向上しており、この性能をスーパーカミオカンデ内で実測した。また、この高性能を引き出すために精度の良い時間較正が必要となり、パルス光の時間幅を保ったまま一様な光量を照射できるデフューザーボール光源を開発した。パルス光の時間特性を損なわず拡散する最適化を検討し、小型な拡散樹脂により一様な照射が可能となった。
I have studied a calibration device to improve the detection accuracy of the next-generation Hyper-Kamiokande experiment, which will probe neutrino and nucleon decay physics. The photon detection performance of the new photomultiplier tube for Hyper-Kamiokande is more than twice that of conventional ones, where accurate time calibration is important to reach the intrinsic performance. Therefore, I studied a diffuser ball light source that can emit a uniform amount of light while minimizing the time width of the pulsed light. Optimization of the magnesium oxide concentration and size of the resin that diffuses the pulsed light without impairing its temporal characteristics was investigated. A uniform irradiation was achieved by using a small diffusing resin with an increased concentration. The correlation between the design and the light attenuation or pulse width was obtained, enabling the design of a diffuse light source that meets the specifications.

研究種目 : 若手研究
研究期間 : 2018～2021
課題番号 : 18K13559
研究分野 : 素粒子実験