The current generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs) operate in the very-high-energy (VHE) domain from ~100 GeV to ~100 TeV. They use electronic digital trigger systems to discern the Cherenkov light flashes emitted by extensive air showers (EASs), from the overwhelming light of the night sky (LoNS) background. Near the telescope energy threshold, the number of emitted Cherenkov photons by gamma-ray-induced EASs is comparable to the fluctuations of the LoNS and the photon distribution at the Cherenkov-imaging camera plane becomes patchy. This results in a severe loss of effectiveness of the digital triggers based on combinatorial logic of thresholded signals. A stereoscopic analog trigger system has been developed for improving the detection capabilities of the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes at the lowest energies. It is based on the analog sum of the photosensor electrical signals. In this article, the architectural design, technical performances, and configuration of this stereoscopic analog trigger, dubbed “Sum-Trigger-II,” are described.

中文翻译：

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MAGIC 望远镜的立体模拟触发器


当前一代地基成像大气切伦科夫望远镜 (IACT) 在 ~100 GeV 至 ~100 TeV 的极高能 (VHE) 范围内运行。他们使用电子数字触发系统从夜空 (LoNS) 背景的压倒性光线中辨别大面积空气阵雨 (EAS) 发出的切伦科夫闪光。在望远镜能量阈值附近，伽马射线诱导的 EAS 发射的切伦科夫光子数量与 LoNS 的波动相当，并且切伦科夫成像相机平面上的光子分布变得不均匀。这导致基于阈值信号的组合逻辑的数字触发器的有效性严重丧失。立体模拟触发系统的开发旨在提高主要大气伽马射线成像切伦科夫（MAGIC）望远镜在最低能量下的探测能力。它基于光电传感器电信号的模拟和。在本文中，描述了这种被称为“Sum-Trigger-II”的立体模拟触发器的架构设计、技术性能和配置。