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arXiv · 2203.06582

Calibration and performance of the readout system based on switched capacitor arrays for the Large-Sized Telescope of the Cherenkov Telescope Array

Seiya Nozaki·Kyosuke Awai·Aya Bamba·Juan Abel Barrio·Maria Isabel Bernardos·Oscar Blanch·Joan Boix·Franca Cassol·Yuki Choushi·Carlos Delgado·Carlos Diaz·Nadia Fouque·Lluis Freixas·Pawel Gliwny·Shunichi Gunji·Daniela Hadasch·Dirk Hoffmann·Julien Houles·Yusuke Inome·Yuki Iwamura·Léa Jouvin·Hideaki Katagiri·Kiomei Kawamura·Daniel Kerszberg·Yusuke Konno·Hidetoshi Kubo·Junko Kushida·Yukiho Kobayashi·Rubén López-Coto·Gustavo Martinez·Shu Masuda·Daniel Mazin·Abelardo Moralejo·Elena Moretti·Tsutomu Nagayoshi·Takeshi Nakamori·Kyoshi Nishijima·Yuto Nogami·Leyre Nogués·Hideyuki Ohoka·Tomohiko Oka·Nao Okazaki·Akira Okumura·Reiko Orito·Jean-Luc Panazol·Riccardo Paoletti·Cristobal Pio·Miguel Polo·Julie Prast·Takayuki Saito·Shunsuke Sakurai·Julian Sitarek·Yuji Sunada·Megumi Suzuki·Mitsunari Takahashi·Kenji Tamura·Manobu Tanaka·Luis Angel Tejedor·Yukikatsu Terada·Masahiro Teshima·Yusuke Tsukamoto·Tokonatsu Yamamoto
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Abstract

The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA is designed to detect gamma rays between 20 GeV and a few TeV with a 23-meter diameter mirror. We have developed the focal plane camera of the first LST, which has 1855 photomultiplier tubes (PMTs) and the readout system which samples a PMT waveform at GHz with switched capacitor arrays, Domino Ring Sampler ver4 (DRS4). To measure the precise pulse charge and arrival time of Cherenkov signals, we developed a method to calibrate the output voltage of DRS4 and the sampling time interval, as well as an analysis method to correct the spike noise of DRS4. Since the first LST was inaugurated in 2018, we have performed the commissioning tests and calibrated the camera. We characterised the camera in terms of the charge pedestal under various conditions of the night sky background, the charge resolution of each pixel, the charge uniformity of the whole camera, and the time resolutions with a test pulse and calibration laser.

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Seiya Nozaki, Kyosuke Awai, Aya Bamba, Juan Abel Barrio, Maria Isabel Bernardos, Oscar Blanch, Joan Boix, Franca Cassol, Yuki Choushi, Carlos Delgado, Carlos Diaz, Nadia Fouque, Lluis Freixas, Pawel Gliwny, Shunichi Gunji, Daniela Hadasch, Dirk Hoffmann, Julien Houles, Yusuke Inome, Yuki Iwamura, Léa Jouvin, Hideaki Katagiri, Kiomei Kawamura, Daniel Kerszberg, Yusuke Konno, Hidetoshi Kubo, Junko Kushida, Yukiho Kobayashi, Rubén López-Coto, Gustavo Martinez, Shu Masuda, Daniel Mazin, Abelardo Moralejo, Elena Moretti, Tsutomu Nagayoshi, Takeshi Nakamori, Kyoshi Nishijima, Yuto Nogami, Leyre Nogués, Hideyuki Ohoka, Tomohiko Oka, Nao Okazaki, Akira Okumura, Reiko Orito, Jean-Luc Panazol, Riccardo Paoletti, Cristobal Pio, Miguel Polo, Julie Prast, Takayuki Saito, Shunsuke Sakurai, Julian Sitarek, Yuji Sunada, Megumi Suzuki, Mitsunari Takahashi, Kenji Tamura, Manobu Tanaka, Luis Angel Tejedor, Yukikatsu Terada, Masahiro Teshima, Yusuke Tsukamoto, Tokonatsu Yamamoto. 2022-03-13. Calibration and performance of the readout system based on switched capacitor arrays for the Large-Sized Telescope of the Cherenkov Telescope Array. https://doi.org/10.1117/12.2560018

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