C. Föhr

Performance Verification of the FlashCam Prototype Camera for the Cherenkov Telescope Array

Abstract The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is planned to significantly improve upon the sensitivity and precision of the current generation of Cherenkov telescopes. The observatory will consist of several dozens of telescopes with different sizes and equipped with different types of cameras. Of these, the FlashCam camera system is the first to implement a fully digital signal processing chain which allows for a traceable, configurable trigger scheme and flexible signal reconstruction. As of autumn 2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears completion. First results of the ongoing system tests demonstrate that the signal chain and the readout system surpass CTA requirements. The stability of the system is shown using long-term temperature cycling.

A Trigger And Readout Scheme For Future Cherenkov Telescope Arrays

The next generation of ground‐based gamma‐ray observatories, such as e.g. CTA will consists of about 50–100 Telescopes, and cameras with in total ∼100000 to ∼200000 channels. The telescopes of the core array will cover and effective area of ∼1 km2 and will be possibly accompanied by a large “halo” of smaller telescopes spread over about 10 km2. In order to make maximum use of the stereoscopic approach, a very flexible inter‐telescope trigger scheme is needed which will allow to couple telescopes that located up to ∼1 km apart. At the same time, the development of a cost effective readout scheme for the camera signals exhibits a major technological challenge. Here we present ideas on a new asynchronous inter‐telescope trigger scheme, and a very cost‐effective, high‐bandwidth frontend to backend data transfer system, both based on standard Ethernet components and an Ethernet front‐end interface based on mass production standard FPGAs.

FlashCam: a novel Cherenkov telescope camera with continuous signal digitization

The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for cosmic gamma rays. The FlashCam camera for its mid-size telescope introduces a new concept, with a modest sampling rate of 250 MS/s, that enables a continuous digitization as well as event buffering and trigger processing using the same front-end FPGAs. The high performance Ethernet-based readout provides a dead-time free operation for event rates up to 30 kHz corresponding to a data rate of 2.0 GByte/s sent to the camera server. We present the camera design and the current status of the project.

Trigger performance verification of the FlashCam prototype camera

Abstract FlashCam is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA). We compare camera trigger rates obtained from measurements with the camera prototype in the laboratory and Monte Carlo simulations, when scanning the parameter space of the fully-digital trigger logic and the intensity of a continuous light source mimicking the night sky background (NSB) during on-site operation. The comparisons of the measured data results to the Monte Carlo simulations are used to verify the FlashCam trigger logic and the expected trigger performance.