Performance of the Magcool-Subcooler Cryogenic System After 50 mm SSC Dipole Quenches

Abstract

The subcooler assembly installed in the MAGCOOL test area at Brookhaven National Laboratory has been used for testing SSC magnets since 1989. As part of the test program, magnets are quenched routinely in the system. The system description and steady state capacity have been given previously¹. In this paper, the thermal behavior of the subcooler cryogenic system after quenches of the 50 mm SSC dipole magnet DCA207 are presented.

Pressures, temperatures and flow rates in the magnet cooling loop are given as a function of time. The heating/cooling and venting mechanisms are illustrated. The cooling rates and the total energy removed by cooling during quench recovery have been calculated for quench currents of 6000, 6883 and 7406 ampere at 4.35 K, and for 8413 ampere at 3.5 K. Results show that the total energy removed by cooling during quench recovery is in good agreement with the stored energy released by the magnet during the quench. No operating difficulties were encountered during the magnet tests. System recovery time varies from 50 minutes for a 6000 ampere quench to 90 minutes for an 8413 ampere quench.

Work supported by the U.S. Department of Energy.