The First Level Trigger of JEM-EUSO: Concept and tests

The trigger system of JEM-EUSO is designed to meet specific challenging requirements. These include managing a large number of pixels (~3·10⁵) and using a very fast, low power consuming, and radiation hard electronics. It must achieve a high signal-to-noise performance and flexibility and cope with the limited down-link transmission rate from the International Space Station (ISS) to Earth. The general overview of the First Level Trigger for cosmic ray detection is reviewed; tests that validate its performance are discussed.