标题： GRBAlpha和VZLUSAT-2立方星上SiPMs超过三年的在轨辐射损伤特性分析 显示英文标题

标题： Characterization of more than three years of in-orbit radiation damage of SiPMs on GRBAlpha and VZLUSAT-2 CubeSats

摘要： 众所周知，硅光电倍增管（SiPMs）容易受到辐射损伤。随着SiPMs在新的星载任务中越来越受欢迎，尤其是在立方星上，对它们在空间环境中的性能进行表征至关重要。在本工作中，我们报告了使用GRBAlpha和VZLUSAT-2立方星在低地球轨道（LEO）上获取的测量数据，对SiPM阵列（所谓多像素光子计数器（MPPCs））的在轨老化进行了研究，时间跨度超过三年，这是前所未有的。GRBAlpha是一颗1U立方星，于2021年3月22日发射至550公里高度的太阳同步极地轨道（SSO），其搭载了一个基于CsI（Tl）闪烁体的伽马射线探测器，由八个MPPCs读出，并定期检测能量范围为~30-900 keV的伽马射线瞬变事件，如伽马暴和太阳耀斑。VZLUSAT-2是一颗3U立方星，于2022年1月13日同样发射至550公里高度的SSO，其搭载了多种有效载荷，其中包括两个与GRBAlpha上的探测器类似的伽马射线探测器。我们已经验证了Hamamatsu MPPCs S13360-3050 PE的飞行可靠性，并证明了由2.5毫米铅锑合金屏蔽的MPPCs可以在持续时间超过三年的科学任务中用于LEO环境。这表明MPPCs在未来卫星中的应用潜力。 显示英文摘要

摘要： It is well known that silicon photomultipliers (SiPMs) are prone to radiation damage. With the increasing popularity of SiPMs among new spaceborne missions, especially on CubeSats, it is of paramount importance to characterize their performance in space environment. In this work, we report the in-orbit ageing of SiPM arrays, so-called multi-pixel photon counters (MPPCs), using measurements acquired by the GRBAlpha and VZLUSAT-2 CubeSats at low Earth orbit (LEO) spanning over three years, which in duration is unique. GRBAlpha is a 1U CubeSat launched on March 22, 2021, to a 550 km altitude sun-synchronous polar orbit (SSO) carrying on board a gamma-ray detector based on CsI(Tl) scintillator readout by eight MPPCs and regularly detecting gamma-ray transients such as gamma-ray bursts and solar flares in the energy range of ~30-900 keV. VZLUSAT-2 is a 3U CubeSat launched on January 13, 2022 also to a 550 km altitude SSO carrying on board, among other payloads, two gamma-ray detectors similar to the one on GRBAlpha. We have flight-proven the Hamamatsu MPPCs S13360-3050 PE and demonstrated that MPPCs, shielded by 2.5 mm of PbSb alloy, can be used in an LEO environment on a scientific mission lasting beyond three years. This manifests the potential of MPPCs being employed in future satellites.