  The magnetic properties of two important passive magnetic shielding materials
(A4K and Amumetal) for accelerator applications, subjected to various
processing and heat treatment conditions are studied comprehensively over a
wide range of temperatures: from Cryogenic to room temperature. We analyze the
effect of processing on the extent of degradation of the magnetic properties of
both materials and investigate the possibility of restoring these properties by
re-annealing.
