Experimental Characterization of Magnetic Materials for the Magnetic Shielding of Cryomodules in Particle Accelerators

TL;DR

This study comprehensively characterizes the magnetic properties of A4K and Amumetal shielding materials across a wide temperature range, examining processing effects and the potential for property restoration through re-annealing.

Contribution

It provides new insights into how processing and heat treatment affect magnetic properties of shielding materials used in cryomodules, including the potential for restoring their performance.

Findings

Processing degrades magnetic properties at cryogenic and room temperatures

Re-annealing can partially restore magnetic properties

Material performance varies significantly with heat treatment conditions

Abstract

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.