The upgrade of the H.E.S.S. cameras

Abstract

International audienceThe High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes (IACT) located in Namibia. In order to assure the continuous operation of H.E.S.S. at its full sensitivity until and possibly beyond the advent of CTA, the older cameras, installed in 2003, are currently undergoing an extensive upgrade. Its goals are reducing the system failure rate, reducing the dead time and improving the overall performance of the array. All camera components have been upgraded, except the mechanical structure and the photo-multiplier tubes (PMTs). Novel technical solutions have been introduced: the upgraded readout electronics is based on the NECTAr analog memory chip; the control of the hardware is carried out by an FPGA coupled to an embedded ARM computer; the control software was re-written from scratch and it is based on modern C++ open source libraries. These hardware and software solutions offer very good performance, robustness and flexibility. The first camera was fielded in July 2015 and has been successfully commissioned; the rest is scheduled to be upgraded in September 2016. The present contribution describes the design, the testing and the performance of the new H.E.S.S. camera and its components

Sensitivity Improvements of Very-High-Energy $\gamma$-Ray Detection with the Upgraded H.E.S.S. I Cameras using Full Waveform Processing

“…4 shows the extracted gain in ADC/p.e. 3 from single photoelectron (SPE) simulations revealing a factor of ∼0.91 between CM and SM gain. This ratio is expected from the integration of the SPE pulse shape (being used as an input to the simulation chain) in two different windows (first 16 ns and 9 ns around the peak of the pulse shape).…”

NectarCAM, a camera for the medium sized telescopes of the Cherenkov telescope array

“…A variant of this trigger design is used by the upgraded H.E.S.S. cameras (see reference [8] for details).…”

Малоразмерный Черенковский Телескоп С Полупроводниковыми Фотодетекторами: Полночастичное Моделирование Порога Регистрации Космических Гамма-Источников

“…Камеры большинства современных черенковских телескопов (MAGIC [1], VERITAS [2], H.E.S.S. [3]) состоят из высоковольтных вакуумных фотоумножителей (ФЭУ). Этот тип фотоэлементов обладает рядом недостатков, таких как сравнительно невысокая эффективность детектирования (как правило, не более 30%), высокое энергопотребление (и высокое напряжение питания > 1000 V), значительные габариты (ограничивающие возможность уменьшения как линейного, так и углового размеров пиксела при заданных конструкциях зеркала и монтировки) и возможность полного выхода из строя при избыточной засветке.…”