Speaker
Description
The COMET experiment aims to search for the muon-to-electron ($\mu$-e) conversion process, one of the lepton flavor violating processes, with a sensitivity better than $10^{-16}$ at J-PARC. To achieve this sensitivity, the muon beam monitor plays a crucial role by monitoring the intensity and stability of the secondary muon beam, which helps suppress false signals caused by sudden beam fluctuations.
This beam monitor will be directly exposed to a high-intensity muon beam, expected to result in a 1-MeV equivalent neutron fluence of $5 \times 10^{13}$ and ionizing radiation of 5 MGy. Given the higher radiation tolerance required compared to the standard n-type silicon sensors, silicon carbide (SiC) is an optimal option for use as the beam monitor. We use a SiC detector jointly developed by KEK and AIST, and the overall system is still under development.
To measure the response of the SiC muon beam monitor when exposed to a pulsed muon beam with the same momentum region as in the main experiment, the beam test was performed at J-PARC MLF in June 2024. In this test, a commercial preamplifier was used for readout and a USB oscilloscope recorded the waveforms. As a result of the analysis, we were able to determine the pulse height corresponding to a single incident muon, and using this information, we confirmed sufficient linearity up to approximately 30 incident muons.
We report the performance evaluation of the SiC muon beam monitor from the beam test and discuss prospects.
| Primary experiment | COMET |
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