LAUSR

We report the effect of permanent magnet (PM) collars on the flux-creep rate of magnetized bulk HTS. The creep rates of single-grain, cylindrical samples are measured with attached collars activated to various fields, B PM, in the range 0??? B PM??? B PM,max, where B PM,max is the fully saturated field of the PM. As B PM varies, the creep rate of the HTS is found to maintain its well-known form?a constant fractional loss ?, of original residual field, per decade of time. However, the magnitude of ? decreases as B PM increases. The decrease in ? is found to be linearly dependent on increasing B PM. The collar field for which flux-creep extrapolates to zero is found to be comparable to the maximum trappable field of the HTS bulk, B T,max. The properties of the dependence of ? on the HTS peak field, B T,max, the PM field, B PM, and the creep rate ? 0 with B PM?=?0 permit the reduced creep rate in these experiments to be predicted by a universal equation.