Single Telescope Trigger for CTA

Abstract

The goal of the LSTs for CTA, is to achieve the lowest possible energy threshold. To push the threshold down in energy, one of the most important systems is the camera trigger, that selects the events that are recorded. Since most of the problems when lowering the energy threshold of the system is that the accidental triggers increase, the trigger system needs to powerfully distinguish between the events containing cosmic showers and the ones containing only noise. Arrays of Cherenkov telescopes typically use multi-level trigger schemes to keep the rate of accidental triggers produced by direct NSB and PMT After Pulses low. At a first stage, individual telescopes produce a trigger signal from the pixel signals in the telescope camera. The final event trigger is then formed by combining trigger signals from several telescopes. I present in this chapter the work performed to develop, test and characterize an analog trigger system for the analog cameras of LSTs and MSTs.