Comparison of approaches to shielding of ADR magnets

An important consideration in the use of magnets in adiabatic demagnetization refrigeration (ADR) applications is shielding of the other instruments in the vicinity of the superconducting magnets. Shielding without proper optimization can add unnecessary weight to the magnet system that can amount to a few times the weight of the superconducting magnet itself. This article reports on examination of various approaches to shielding of ADR magnets, and measurements conducted on both passive and active shielding of a sample Nb3Sn solenoidal magnet. Shielded ADR solenoidal magnets are also compared with self-shielding toroidal magnets in terms of overall weight, volume, and cooling capacity.