Magnetic Shielding

The article gives a fairly extensive review of the available literature about low-H magnetic shielding. Beginning with ferromagnetic cylindrical shieldings, the theoretical design equations for transversal and longitudinal DC and low frequency (_??_1MHZ) AC fields, inclusive leakage fields from the ends, are presented, disussed and compared with actually designed shields. Experimental procedures (demagnetization and shaking), which help to raise the shielding ratio together with limits and problems of such shieldings are listed. Superconducting shielding is covered in three sections: stationary, rotating, and expanding (balloon-type) shieldings, and again, a survey of results achieved and limits of superconducting shieldings are presented. Finally, a short section covers the main features of active shielding with degaussing coils. An appendix outlines methods of shielding against strong fields and shortly discusses conventional low-H magnetometers. A list of the major literature is added.