Speaker
Description
The Mu2e Cosmic Ray Veto (CRV) suppresses cosmic-ray backgrounds that could mimic the experiment’s rare conversion-electron signal. It uses four-layer scintillator modules with SiPM readout to achieve the high veto efficiency required for Mu2e. The CRV is now progressing toward sustained cosmic-ray operation and is being operated as a complete system to exercise calibration, reconstruction, monitoring, slow controls, and DAQ integration. Preliminary measurements show veto efficiencies above 99.9%, and Run-2 studies indicate that low projected deadtime can be achieved while preserving performance. The ongoing cosmic-ray campaign is testing stability, timing and synchronization, calibration, automated processing, and data quality while resolving remaining electronics and DAQ issues. This talk will present recent CRV performance, lessons from cosmic-ray running, and the remaining steps toward full installation and integration with the Mu2e detector for Run-1.