Demonstrateur d'élément modulaire de caméra pour CTA – NeCTAr

The high energy gamma ray astronomy is a new emerging field of astroparticle physics. It detects gamma rays with energy in the range 10 GeV-100 TeV. The best results have been obtained with small arrays of ground-based Cherenkov telescopes. The most advanced example is the H.E.S.S. array, which has four operational telescopes. We propose to study a new front-end electronics for cameras which will be installed on the next generation of Cherenkov telescopes, the Cherenkov Telescope Array. The CTA, which is an array of hundred telescopes, should start taking data around 2015. The large number of telescopes in the array brings new constraints compared to existing instruments. The cost of components, which will be built on a large scale by the industry, should be reduced. At the same time, the performance of the components should be improved. In order to achieve these two contradictory goals, one will have to redefine globally the concept of the camera, both on an electronic and a mechanical point of view. The components will have a large degree of integration. They should be modular so that they are easily installed and replaced. The electronics should adapt to the new global trigger strategy of the array of telescopes. The study we propose is aimed at studying a full detection module. This module, which meets the requirements of CTA, has photo-detectors coupled to an electronics board. This board houses simultaneously the front-end and trigger electronics. The study will use the knowledge accumulated over the years by the French teams in building cameras for Cherenkov telescopes (in the CAT, H.E.S.S. and H.E.S.S.-II experiments) . The participating labs are the CEA-IRFU at Saclay, the LPNHE in Paris and the LPTA in Montpellier. The LPTA will run physics simulations to define the requirements of the front-end and trigger electronics and more generally of the detection module. The requirements on the electronics and local trigger depend on the global trigger strategy of the telescope array. The elaboration of the electronics blue-print will take roughly one year. During the last year, the simulations results will be compared to those of the demonstrator tests. From the electronics point of view, an improvement of performances and a cost reduction can be obtained by integrating the largest number of functionalities on the same ASIC, on one hand and on the same electronics board, on the other hand. The large integration of functionalities will lower the weight of the electronics boards and will allow to obtain more compact designs for the cameras. The CEA-IRFU will design and test new ASICs. The design of the new ASIC architectures will take a full year. The ASICs will be prototyped and tested. Finally, we propose to build and test a demonstrator to check the viability of the architecture of the electronics board. The demonstrator will include several detection modules. The LPNHE will work on the demonstrator electronics, global architecture and tests. The demonstrator will be built during the second year of the study and tested during the third year. The total amount of funding asked is 365700 euros. The total amount includes a funding for manpower by the LPTA and for hardware by the CEA-IRFU and the LPNHE. The construction and tests of the demonstrator will be major steps in the path towards the CTA.