Item

Abstract

The future Cherenkov Telescope Array (CTA) will consist of several tens of telescopes of different mirror areas. CTA will provide next generation sensitivity to very high energy photons over a wide energy range from few tens of GeV to > 100 TeV. The signals of the photon detectors in the focal plane will be read out with custom-designed, fast digitization and trigger- ing electronics. Within CTA, several camera electronics options are being evaluated. The FlashCam approach is unique here since data processing inside the camera is fully digital. Signal digitization and trigger processing are jointly per- formed in one single readout chain per detector pixel. For a group of pixels, such a chain consists of Flash ADCs and a Field-Programmable Gate Array (FPGA) module, both commercially available and reasonably priced. A camera-wide event trigger is subsequently computed in separate trigger units. The camera data is transferred from the cameras over ethernet to a central computer farm using a custom network protocol. Such a fully digital approach using state-of-the-art components provides accurate triggering and an easily scalable architecture in a cost-effective way. The FlashCam team is also evaluating the concept of a horizontal camera integration. Here, the photon detector plane is sustained by a monolithic carrier holding photon detectors, high voltage supplies, and preamplifiers only. The signal digitization and triggering electronics are organized in bo ards and crates which are kept at the rear side of the camera body. Such an approach allows different photon detectors to be adopted and might result in cost saving.