A Combined Mu-Metal and Superconducting Shield for a Cryogenic Sensor Enclosure: Layer Budget, Saturation Margin and Residual Field

This paper presents a computed design for a combined shield intended for magnetic shielding for cryogenic sensors, with its performance, resource budgets and margins derived from stated assumptions rather than asserted. The headline results are: combined shielding factor of the two mu-metal shells of 1.8e+04 dimensionless; static residual field inside the ferromagnetic shells of 0.00277 microtesla; estimated peak induction in the outer mu-metal shell of 0.005 T; ratio of saturation induction to the estimated operating induction of 150 dimensionless; residual from a one-microtesla external fluctuation after all layers of 5.55e-06 nT. Each figure was produced by the deposited computation from the inputs listed in the Methods, and the sensitivity of the conclusions to those inputs is examined in the Discussion. The design is a paper study: it is labelled, on its face and in this abstract, SIMULATED, NOT MEASURED, and no quantity reported here is a measurement of built hardware.