Performance of the Thin Superconducting Solenoid of the CMD-3 Detector

A thin superconducting solenoid is designed to provide a magnetic field of 1.5 T in the CMD-3 detector. The solenoid and an LXe calorimeter are placed in the common vacuum vessel of the detector. The solenoid is passively protected by subdivision and inductive coupling methods. The radiation thickness of the coil is 0.085X₀, and the achieved E/M ratio is 6.9 kJ/kg. In 2007, the solenoid was tested in a prototype iron yoke, where the operational parameters were achieved. This paper reports the performance of the solenoid in the CMD-3 detector. The solenoid has been operated safely at a 1.35-T magnetic field. There were 19 quenches caused by various factors at magnetic fields in the range of 0.6-1.38 T. After a quench, the solenoid absorbed about 40% of the stored energy and warmed up to 42-55 K. A significant influence of quench-induced eddy currents on the detector design elements was observed. Liquid helium consumption at steady operation was about 3.5 L/h. Possible application of the achieved results to designing thinner solenoids is discussed.