Commissioning of the camera of the first Large Size Telescope of the Cherenkov Telescope Array

Discussion timeslot (ZOOM-Meeting): 16. July 2021 - 18:00
ZOOM-Meeting URL: https://icrc2021.desy.de/pf_access_abstracts
Corresponding Session: https://icrc2021-venue.desy.de/channel/Presenter-Forum-1-Evening-All-Categories/48
Abstract:
'The first Large Size Telescope (LST-1) of the Cherenkov Telescope Array has been operational since October 2018 at La Palma, Spain, and its camera has been under commissioning. The camera of LST consists of 265 modules, each of which is equipped with 7 PMTs. An analog trigger system is implemented where PMT signals from 3 modules (21 pixels) are summed up before a discriminator. Upon the triggers, the events are readout with a high speed DAQ system with a 60 Gbps bandwidth. In addition, the dedicated system that provides a ~2 ns width UV laser pulse, whose intensity is monitored with a 1% precision, is used to monitor and calibrate the camera performance on a daily basis. rn In this contribution we report on the results obtained during the camera commissioning. The commissioning process of the camera required to perform tasks such as flatfielding of PMT gains with a 2% homogeneity, timing calibration for the analog sum trigger with a few ns precision, synchronization of the clock and the trigger propagation within 1 ns accuracy. Moreover, the requirement for the DAQ system was to acquire data at a trigger rate higher than 15 kHz. A deep understanding of the night sky background light and its impact on the trigger and the signal readout were also essential.'

Authors: Takayuki Saito | Carlos Delgado | Oscar Blanch Bigas
Co-Authors: Manuel Artero | Juan Abel Barrio | Franca Cassol | Carlos Diaz Ginzo | Daniela Hadasch | Dirk Hoffmann | Julien Houles | Yusuke Inome | Maurizio Iori | Lea Jouvin | Yukiho Kobayashi | Daniel Kerszberg | Hidetoshi Kubo | Gustavo Martinez | Daniel Mazin | Elena Moretti | Takeshi Nakamori | Seiya Nozaki | Tomohiko Oka | Akira Okumura | Michele Palatiello | Cristobal Pio | Miguel Polo | Julie Prast | Shunsuke Sakurai | Yuji Sunada | Mitsunari Takahashi | Ryuji Takeishi | Luis Angel Tejedor | Tokonatsu Yamamoto | Tatsuo Yoshida | for the CTA LST project
Collaboration: CTA

Indico-ID: 509
Proceeding URL: https://pos.sissa.it/395/718