Development of AC-LGAD for Precision Measurement with High-Intensity Pulsed Muon Beam

At the Muon Experimental Facility (MUSE) of the Materials and Life Science Experimental Facility (MLF) at J-PARC, a wide range of researches including muon precision measurement experiments and physical properties experiments are being conducted or planned using high-intensity pulsed muon beams. By using high-intensity pulsed beams, high statistics can be obtained in a short time. On the other hand, distortion of time spectra due to pile-up event loss is a major problem. We focused on the Low Gain Avalanche Detector (LGAD), which can segment the detector and signal pulses return to their original level within a few nanoseconds.

Since no LGAD has ever been irradiated to a high-intensity pulsed beam, it is necessary to develop a new dedicated detector. A first beam test was performed at the J-PARC MLF MUSE S1 area to confirm that the Capacitive Coupled LGAD (AC-LGAD) sensor can detect muon decay positrons. As a result, the waveform was found to be sufficiently fast. In this talk, we will report the results of the beam test.