Construction and Commissioning Status of the Superconducting Magnets for COMET Phase-I Experiment at J-PARC

Authors

Naoyuki Sumi; Makoto Yoshida; Masami Iio; Noriyuki Kurosawa; Yasuhiro Makida; Toru Ogitsu; Hirokatsu Ohhata, Takahiro Okamura, Masaya Oonaka, Ken-ichi Sasaki, Satoshi Mihara, Masaharu Aoki, Norihito Ohuchi, Yasushi Arimoto, Kazuyuki Aoki

Affiliations

High Energy Accelerator Research Organization, J-PARC center, Tokai-mura, Ibaraki, Japan
Osaka University, Toyonaka, Osaka, Japan

Journal

Published Date

2/22/23

DOI

Abstract

A new muon beamline is under construction for the COMET Phase-I experiment at J-PARC. The experiment requires a negative muon beam with the world-highest intensity to search for muon-electron conversion processes. The muon beamline consists of a series of superconducting solenoid magnets to generate muons by 8 GeV pulsed proton beam from MR of J-PARC, to transport muons to the detectors. A radiation-tolerant superconducting solenoid, the Pion Capture Solenoid, is developed to generate a high magnetic field on a production target to trap pions and muons efficiently. A long curved solenoid, the Muon Transport Solenoid, with correction dipole coils is utilized not only to transport muons but also to select low-momentum muons against unnecessary particles. A large detector solenoid is planned to connect to the muon beamline with a gradually reduced solenoidal field tuned by additional small solenoids. This paper reports the status of the construction and commissioning of the superconducting magnet system.