Development of a SciFi-based beam monitor for COMET

TL;DR

This paper presents the development and testing of a SciFi-based beam monitor for the COMET experiment, enabling precise measurement of muon beam characteristics crucial for its physics goals.

Contribution

The paper introduces a novel Muon Beam Monitor using scintillation fibers and SiPMs, with successful testing and data collection demonstrating its effectiveness.

Findings

Successful beam profile and timing measurements with SciFi detector

Effective performance in the COMET Phase-α commissioning run

Validated mechanical and electronic design for muon beam monitoring

Abstract

COMET is a leading experiment to search for coherent conversion of $\mu^- \mathrm{N}\to e^- \mathrm{N}$ with a high-intensity pulsed muon beamline, produced by the innovative slow extraction techniques. Therefore, it is critical to measure the characteristics of the muon beam. We set up a Muon Beam Monitor (MBM), where scintillation fibers (SciFi) weaved in the cross shape are coupled to silicon photomultipliers (SiPM), to measure the spatial profile and timing structure of the extracted muon beam for COMET. The MBM detector has been tested successfully with a proton beamline in China Spallation Neutron Source (CSNS) and taken data with good performance in the commissioning run called COMET Phase-$\alpha$. Experience of the MBM development, such as the mechanical structure and electronics readout, and its beam measurement results will be shared.