title: Precooling of a superconducting magnet using a cryocooler and thermal switches.
abstract: A simple precooling system for a superconducting magnet is developed using a Cryomech GB02 cryocooler and gas filled thermal switches. A superconducting magnet (NbTi wire, 7 T of maximum field, 5.6 kg of weight) is precooled to 16 K in about 70 h without any manual control. Heat transfer rate of each thermal switch (H2 or N2 gas filled at 1.3 MPa at room temperature) is about 3x10(-1) W/K during the ON state, and 5x10(-3) W/K during the OFF state.
authors.affiliation: Osaka University, Low Temperature Center, Suita, Osaka 565, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Yanai