In-beam performance of neutron irradiated MIMOSIS-1 CMOS Monolithic Active Pixel Sensors

MIMOSIS is the CMOS Monolithic Active Pixel Sensor designed for the Micro Vertex Detector (MVD) of the Compressed Baryonic Matter (CBM) experiment currently under development at FAIR. The sensors have to combine a spatial and a time resolution of 5 µm and 5 µs, handle a peak hit rate of ∼ 80 MHz/cm 2 , and to withstand Total Ionizing radiation Doses (TID) of ∼ 5 MRad and Non-Ionizing Energy Loss (NIEL) fluences of ∼ 7 × 10 13 n eq /cm 2 before being replaced. Prior to their use in the experiment, the sensors undergo lab and in-beam tests, to qualify their performance in charged particles detection. In this work we present the sensor design and concept, a summary of its requirements as a candidate for the CBM-MVD, followed by the performance results of the first full-size prototype, MIMOSIS-1, from in-beam tests done at DESY and CERN, after being irradiated to different TID and NIEL fluences.