发表机构
Institute for Cosmic Ray Research, University of Tokyo; Graduate School of Science and Engineering, Saitama University; Department of Physics, Tokai University; Aix Marseille Univ, CNRS/IN2P3, CPPM; Department of Physics, Yamagata University（东京大学宇宙线研究所; 埼玉大学理工学研究科; 东海大学物理系; 艾克斯-马赛大学，法国国家科学研究中心/欧洲核子研究组织粒子与高能物理研究所; 山形大学物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分析CTAO LST-1校准数据及实验室测量，证实光电倍增管增益对地磁场的依赖源于磁场效应，并区分了其对增益和过剩噪声因子的影响。
AI 中文摘要
光电倍增管（PMT）广泛应用于成像大气切伦科夫望远镜中。其响应可能因望远镜指向方向变化导致其相对于地磁场的取向改变而受到影响。在CTAO LST-1的校准活动中，这种依赖性已被指出。本研究分析了LST-1的校准数据，以量化增益对地磁场的依赖关系，并进行了专门的实验室测量，以检验观测到的依赖性源于磁场效应的假设。现场测量和实验室测量均显示PMT增益对磁场具有一致的依赖性，而实验室测量进一步区分了磁场对增益和过剩噪声因子的影响。这些结果从磁场效应的角度为理解LST-1中观测到的增益变化提供了更清晰的认识。
英文摘要
Photomultiplier tubes (PMTs) are widely used in imaging atmospheric Cherenkov telescopes. Their response can depend on the telescope pointing direction through changes in their orientation relative to the geomagnetic field. Such a dependence was indicated during the calibration campaign of the CTAO LST-1. In this work, the LST-1 calibration data are analyzed to quantify the gain dependence in terms of the geomagnetic field, and dedicated laboratory measurements are performed to test the hypothesis that the observed dependence originates from magnetic-field effects. Both the on-site and laboratory measurements show a consistent dependence of the PMT gain on the magnetic field, while the laboratory measurements further separate the effects on the gain and the excess noise factor. These results provide a clearer understanding of the gain variation observed in LST-1 in terms of magnetic-field effects.
Comments21 pages, 10 figures. Submitted to Nuclear Instruments and Methods in Physics Research, Section A
