CBM T0 Detector Performance Study with Light Ions (4He, 12C) and the DOGMA Readout System
This paper presents the realization and performance of the CBM T0 detector system. Built upon an approximately 70 μm thin polycrystalline CVD (pcCVD) diamond sensor with pad metallization, the detector is mounted on a flexible vacuum manipulator and operates entirely under passive cooling. Interfaced with the DOGMA readout architecture, the system successfully meets all operational requirements for CBM. It demonstrates a high detection efficiency (near 100%) and a timing precision below 50 ps RMS across a broad range of beam species, from light ions (such as Carbon) to heavy ions (such as Gold). The DOGMA readout features two distinct data paths: a high-precision TDC path routing data directly to the global CBM DAQ, and a secondary path deliver in real-time rate measurements crucial for online beam quality monitoring and fast beam abort logic. Finally, detailed performance studies conducted with light-ion beams at EBG MedAustron are discussed.