Mechanical Analysis of Pion Capture Superconducting Solenoid System for COMET Experiment at J-PARC

KEK is currently constructing a long series of superconducting solenoid beamline for the COMET Phase-I experiment at the Hadron facility of J-PARC. The magnet system consists of a 5-T pion capture solenoid, a curved muon transport solenoid, and a large bore detector solenoid. The pion capture solenoid system consists of a large cold mass including four coils with an inner diameter of 1340 mm and a small cold mass including six small coils with an inner diameter of 500 mm. The peak magnetic field on the conductor reaches to 5.4 T at an operation current of 2700 A. This paper presents the design and structural details of a magnet, radiation-resistant coil, cold mass and vacuum vessel, apart from the results of the electromagnetic analysis in two-dimensional (2-D) and 3-D.