Ramp-rate limitation experiment using induced current method. Part 2: analysis

Abstract

This paper describes an analysis of ramp-rate limitation experiments performed by a background magnet only without a power supply for the tested cable. Three-strand U-shape cable-in-cond nit conductor samples show distinctive ramp-rate limitation phenomena with sensitive transition between no-quench and quench results. Quench experimental results at various ramp rates are explained by a representative induced loop current model. Since the sample length is less than 1 m and the loop resistance through the joint is an order of 1 muOmega, the dominant loop current is induced mostly through the joint. Multiple quench-recovery processes during continuous magnetic field ramp are also explained due to fast recovery of the sample after quench. It is experimentally observed that the strand heat flux condition can be very influential to determine quench-recovery process near the critical heat flux regime of liquid helium. (C) 2003 Elsevier Ltd. All rights reserved.