Development of a Cylindrical Drift Chamber for the COMET Phase-I Experiment
Résumé
A search for \(\mu \)–e conversion, the COMET experiment, will be conducted at J-PARC. The experiment has two phases. Phase-I aims to measure the background directly and search for \(\mu \)–e conversion with a sensitivity of 10^−15. Phase-II will use the information gained in Phase-I and utilize a much more intense muon beam to achieve a sensitivity of 10^−17. The main detector of the COMET Phase-I experiment is a cylindrical drift chamber (CDC). The COMET CDC will be installed in a solenoidal magnetic field, surrounding the muon stopping targets. It was designed to efficiently detect signal electrons of \(\mu \)–e conversion (105 MeV/c) emitted from the targets with momentum resolution of 200 keV/c. The COMET CDC has already been constructed and the performance test using cosmic ray is in progress. The details of the CDC design and the analysis results of the cosmic ray test is reported.