PDF(Pubmed)
Abstract：
Silicon Photomultipliers (SiPMs) are single photon detectors that gained increasing interest in many applications as an alternative to photomultiplier tubes. In the field of space experiments, where volume, weight and power consumption are a major constraint, their advantages like compactness, ruggedness, and their potential to achieve high quantum efficiency from UV to NIR makes them ideal candidates for spaceborne, low photon flux detectors. During space missions however, SiPMs are usually exposed to high levels of radiation, both ionizing and non-ionizing, which can deteriorate the performance of these detectors over time. The goal of this work is to compare process and layout variation of SiPMs in terms of their radiation damage effects to identify the features that helps reduce the deterioration of the performance and develop the next generation of more radiation-tolerant detectors. To do this, we used protons and X-rays to irradiate several Near Ultraviolet High-Density (NUV-HD) SiPMs with small areas (single microcell, 0.2 × 0.2 mm2 and 1 × 1 mm2) produced at Fondazione Bruno Kessler (FBK), Italy. We performed online current-voltage measurements right after each irradiation step, and a complete functional characterization before and after irradiation. We observed that the main contribution to performance degradation in space applications comes from proton damage in the form of an increase in primary dark count rate (DCR) proportional to the proton fluence and a reduction in activation energy. In this context, small active area devices show a lower DCR before and after irradiation, and we propose light or charge-focusing mechanisms as future developments for high-sensitivity radiation-tolerant detectors.
摘要：
硅光电倍增管（SiPM）是单光子探测器，在许多应用中作为光电倍增管的替代品引起了越来越多的兴趣。在太空实验领域，其中音量，重量和功耗是一个主要制约因素，它们的优点如紧凑，坚固，它们具有从紫外线到近红外的高量子效率的潜力，使它们成为星载的理想候选者，低光子通量探测器。然而，在太空任务中，SiPM通常暴露在高水平的辐射下，电离和非电离，随着时间的推移会使这些探测器的性能恶化。这项工作的目标是根据其辐射损伤效应比较SiPM的工艺和布局变化，以识别有助于减少性能恶化的特征，并开发下一代更耐辐射的探测器。要做到这一点，我们使用质子和X射线以小面积（单个微单元，0.2×0.2mm2和1×1mm2）在FondazioneBrunoKessler（FBK）生产，意大利。我们在每个辐照步骤后立即进行在线电流-电压测量，以及辐照前后的完整功能表征。我们观察到，对空间应用中性能下降的主要贡献来自质子损伤，其形式是与质子注量成正比的初级暗计数率（DCR）增加和活化能减少。在这种情况下，小有源区器件在辐照前后显示出较低的DCR，我们提出光或电荷聚焦机制作为高灵敏度耐辐射探测器的未来发展。
