The readout system based on the ultra-fast waveform sampler DRS4 for the Large-Sized Telescope of the Cherenkov Telescope Array

• Published in: Journal of physics. Conference series 2020-02, Vol.1468 (1), p.12104
• Main Authors: Nozaki, S, Blanch, O, Delgado, C, Gliwny, P, Hadasch, D, Inome, Y, Katagiri, H, Kubo, H, Kobayashi, Y, Mazin, D, Moralejo, A, Nogami, Y, Paoletti, R, Saito, T, Sakurai, S, Sitarek, J, Takahashi, M, Teshima, M, Yamamoto, T
• Format: Article
• Language: English
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1468/1/012104

The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. By using three types of telescopes CTA can cover a wide energy range (20 GeV–300 TeV) with an order of magnitude higher sensitivity than the current telescopes. The Large-Sized Telescope (LST) is designed to detect 20 GeV–1 TeV gamma rays thanks to the large light collection area, sensitive photosensors, a fast trigger system, and readout electronics. The camera readout system must have a high signal-to-noise ratio and a linear signal sampling with a large dynamic range in order to efficiently detect dim and low-energy atmospheric showers. To meet this requirement we use the Domino Ring Sampler version 4 (DRS4), which also enables ultra-fast sampling with low power consumption. Some of the intrinsic characteristics of DRS4 chips require software corrections. These procedures lower the effect of non-Gaussian noise contribution and improve the timing resolution of the system. In this contribution we discuss the calibration algorithms and the resulting performance.