The calibration of the first Large-Sized Telescope of the Cherenkov Telescope Array
The calibration of the first Large-Sized Telescope of the Cherenkov Telescope Array
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切伦科夫望远镜阵列第一台大型望远镜的标定
DOI：
10.22323/1.358.0780
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
R. L'opez
中科院分区：
文献类型：
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作者：
S. Sakurai;D. Depaoli;R. L'opez
切伦科夫望远镜阵列（CTA）代表了下一代高能伽玛射线天文台，它将以前所未有的灵敏度提供从20 GeV到300 TeV的伽玛射线的广泛覆盖。CTA将使用三种不同尺寸的望远镜，其中直径23米的大型望远镜（LSTs）将提供最低能量至20 GeV的灵敏度。首个LST原型已于2018年10月在拉帕尔马（西班牙加那利群岛）落成，并已进入调试阶段。LST的摄像机由265个PMT模块组成。每个模块都配备了7个高量子效率光电倍增管（pmt），一个慢速控制板和一个读出板。确保相机的高均匀性和精确表征是导致LST相机最佳性能和低系统不确定性的关键方面。因此，在现场安装之前，我们对所有PMT模块进行了质量检查。此外，光通量的绝对校准对于重建望远镜接收的光量至关重要。光的数量受到大气、望远镜光学系统和照相机的影响，并且可以使用宇宙射线μ子产生的环形图像进行校准。在这篇文章中，我们将展示PMT模块的非现场质量控制和使用μ子环的现场校准的结果。我们还将重点介绍硅光电倍增管模块的发展现状，该模块可被视为PMT模块的替代品，以进一步改进相机。
The Cherenkov Telescope Array (CTA) represents the next generation of very high-energy gamma-ray observatory, which will provide broad coverage of gamma rays from 20 GeV to 300 TeV with unprecedented sensitivity. CTA will employ three different sizes of telescopes, and the Large-Sized Telescopes (LSTs) of 23-m diameter dish will provide the sensitivity in the lowest energies down to 20 GeV. The first LST prototype has been inaugurated in October 2018 at La Palma (Canary Islands, Spain) and has entered the commissioning phase. The camera of the LST consists of 265 PMT modules. Each module is equipped with seven high-quantum-efficiency Photomultiplier Tubes (PMTs), a slow control board, and a readout board. Ensuring high uniformity and precise characterization of the camera is the key aspects leading to the best performance and low systematic uncertainty of the LST cameras. Therefore, prior to the installation on site, we performed a quality check of all PMT modules. Moreover, the absolute calibration of light throughput is essential to reconstruct the amount of light received by the telescope. The amount of light is affected by the atmosphere, by the telescope optical system and camera, and can be calibrated using the ring-shaped images produced by cosmic-ray muons. In this contribution, we will show the results of off-site quality control of PMT modules and on-site calibration using muon rings. We will also highlight the status of the development of Silicon Photomultiplier modules that could be considered as a replacement of PMT modules for further improvement of the camera.