Performance of the New FlashCam-based Camera in the 28\,m Telescope of H.E.S.S

TL;DR

This paper reports on the performance, stability, and calibration of a new FlashCam-based camera installed on the 28 m H.E.S.S. telescope, demonstrating its high event rate capability and reliable operation in the field.

Contribution

It presents the first operational results of a novel, fully digital FlashCam camera in a large Cherenkov telescope, highlighting its performance and stability in real-world conditions.

Findings

High dynamic range over 3,000 photoelectrons achieved

Stable operation and reliable calibration over one year

Effective trigger and readout system at high event rates

Abstract

In October 2019, the central 28 m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the Medium-Sized Telescopes of the Cherenkov Telescope Array (CTA), with emphasis on cost and performance optimization and on reliability. The fully digital design of the trigger and readout system makes it possible to operate the camera at high event rates and to precisely adjust and understand the trigger system. The novel design of the front-end electronics achieves a dynamic range of over 3,000 photoelectrons with only one electronics readout circuit per pixel. Here we report on the performance parameters of the camera obtained during the first year of operation in the field, including operational stability and optimization of calibration algorithms.