Diamond detector for beam profile monitoring in COMET experiment at J-PARC

We present the design and initial prototype results of a proton beam profile monitor for the COMET experiment at J-PARC. The goal of COMET is to look for charged lepton flavor violation by direct μ to e conversion at a sensitivity of 10−19. The 8 GeV proton beam pulsed at 100 ns with 1010 protons/s will be used to create muons through pion production and decay. In the final experiment, the proton flux will be raised to 1014 protons/s to increase the sensitivity. These requirements of harsh radiation tolerance and fast readout make diamond a good choice for constructing a beam profile monitor in COMET. We present first results of the characterization of single crystal diamond (scCVD) sourced from a new company 2A SYSTEMS Singapore. Our measurements indicate excellent charge collection and high carrier mobility down to cryogenic temperatures.