The Phase-1 Upgrade of the ATLAS Level-1 Endcap Muon Trigger

Abstract

For Run 3 (from 2021), the LHC will undergo a significant increase in instantaneous luminosity to 1.5 times its current value which will lead to larger collected statistics and an enhanced sensitivity to new physics. The Phase-1 upgrade of the ATLAS Level-1 endcap muon trigger is essential to keep the physics acceptance at Run 3. A new trigger logic to take coincidence with detectors inside and outside the magnetic field is described and is shown to reduce the trigger rate to lower than the required level in Run 3. A new trigger board, NSL, to integrate all the information from various detectors, has been developed, and the implementation of the new logic on the FPGA has been successfully demonstrated.