Indirectly Cooled Superconducting Power Supply for the CMD-3 Thin Solenoid

In this paper, a thin superconducting solenoid is used to provide magnetic field in the CMD-3 particle detector. The solenoid is powered by a full-wave ac-dc superconducting rectifier. The rectifier is a current step-up superconducting transformer with two thermally controlled superconducting switches connected to its secondary windings. The CMD-3 solenoid is indirectly cooled, therefore the indirect cooling method is used for the rectifier as well instead of a conventional liquid helium bath. The rectifier charges and discharges the solenoid, and provides long-term magnetic field stabilization. The CMD-3 solenoid operational magnetic field is 1.3 T with 927 A current. The rectifier charges the solenoid to this field within 7 h. Achieved long-term stability of the field is 2 × 10
^-5
T. The rectifier has been demonstrating good reliability since 2010, when the magnet system of the CMD-3 had been commissioned. Design, test results, and performance of the rectifier are reported in this paper.