Development of a microchannel plate based beam profile monitor for a re-accelerated muon beam

A beam profile monitor (BPM) based on a microchannel plate has been developed for muon beams with low transverse momentum for the measurement of the muon anomalous magnetic moment and electric dipole moment at high precision, with capability of diagnosing muon beams of kinetic energy range from a few keV to 4  MeV. The performance of the BPM has been evaluated using a surface muon beam at J-PARC and additionally with an ultraviolet (UV) light source. It has been confirmed that the BPM has a dynamic range from a few to 104 muons per bunch without saturation. The spatial resolution of the BPM has been estimated to be less than 0.30  mm. The positron background from muon decays is an obstacle in muon beam profile monitoring and a partial discrimination of the positrons has been achieved under discrete particle conditions.