Upgraded Cameras for the H.E.S.S. Imaging Atmospheric Cherenkov Telescopes

Gianluca Giavitto , Terry Ashton , Arnim Balzer , David Berge , Francois Brun (1) , Thomas Chaminade (1) , Eric Delagnes (1) , Gérard Fontaine (2) , Matthias Füssling , Berrie Giebels (2) , Jean-François Glicenstein (1) , Tobias Gräber , James Hinton , Albert Jahnke , Stefan Klepser , Marko Kossatz , Axel Kretzschmann , Valentin Lefranc (1) , Holger Leich , Hartmut Lüdecke , Iryna Lypova , Pascal Manigot (2) , Vincent Marandon , Emmanuel Moulin (1) , Mathieu De Naurois (2) , Patrick Nayman (3) , Marek Penno , Duncan Ross , David Salek , Markus Schade , Thomas Schwab , Rachel Simoni , Christian Stegmann , Constantin Steppa , Julian Thornhill , François Toussnel (3)

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 LLR - Laboratoire Leprince-Ringuet
3 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies

The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes, sensitive to cosmic gamma rays of energies between ~30 GeV and several tens of TeV. Four of them started operations in 2003 and their photomultiplier tube (PMT) cameras are currently undergoing a major upgrade, with the goals of improving the overall performance of the array and reducing the failure rate of the ageing systems. With the exception of the 960 PMTs, all components inside the camera have been replaced: these include the readout and trigger electronics, the power, ventilation and pneumatic systems and the control and data acquisition software. New designs and technical solutions have been introduced: the readout makes use of the NECTAr analog memory chip, which samples and stores the PMT signals and was developed for the Cherenkov Telescope Array (CTA). The control of all hardware subsystems is carried out by an FPGA coupled to an embedded ARM computer, a modular design which has proven to be very fast and reliable. The new camera software is based on modern C++ libraries such as Apache Thrift, ØMQ and Protocol buffers, offering very good performance, robustness, flexibility and ease of development. The first camera was upgraded in 2015, the other three cameras are foreseen to follow in fall 2016. We describe the design, the performance, the results of the tests and the lessons learned from the first upgraded H.E.S.S. camera.© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Mots clés: photomultiplier; programming; HESS; data acquisition; upgrade; FPGA; electronics: readout; integrated circuit; detector: design; Cameras; Atmospheric Cherenkov telescopes; Photomultipliers; Software; Stereoscopy; C++; Computer hardware; Computing systems; Data acquisition; Data storage; Electronics; Field programmable gate arrays; Gamma radiation; Cherenkov counter: imaging; performance; trigger

Domaines: Instrumentations et Détecteurs [physics.ins-det]

Gianluca Giavitto, Terry Ashton, Arnim Balzer, David Berge, Francois Brun, et al.. Upgraded Cameras for the H.E.S.S. Imaging Atmospheric Cherenkov Telescopes. Ground-based and Airborne Instrumentation for Astronomy VI, Jun 2016, Edinburgh, United Kingdom. pp.99082H, ⟨10.1117/12.2231865⟩. ⟨hal-02008921⟩