Simple Analytical Models of an Electromagnetically Thin Nonmagnetic Conducting Cylindrical Shell Rotating in External, Static, and Slowly Time-Varying Magnetic Fields

This letter presents very simple analytical models for calculating the effectiveness of static and low frequency magnetic fields shielding by means of rotating electromagnetically thin nonmagnetic conducting cylindrical shells. In fact, "thin" means that the shells may be of any thickness, but must be thinner or at most comparable to the diffusion skin depth, which is not a particularly high requirement in practical constructions of this type. Useful expressions for the shielding factors that contain only elementary functions are given. The new formulas, which can be called "engineering formulas for quick evaluation," are much simpler than those published earlier and work correctly in a wide range of changes in model parameters. The scope of applicability of the proposed analytical models has been analyzed.