EFFECTIVENESS AND DISSIPATION IN CRYOGENIC SHIELDS FOR SUPERCONDUCTING FIELD WINDINGS*

ABSTRACT

This paper is a contribution to the analysis of rotor shielding systems, particularly with respect to shielding and losses in cryogenic shielding systems. The method of surface wave impedance is used in a modified way, and extended to accomodate transposed shields. Solid shields are found to have good shielding properties but relatively large losses, while transposed shields have lower losses but poor shielding. Combination screens may be expected to present satisfactory characteristics, but only with the provision of adequate radial spacing within the rotor.