The similarities in loss creation in LTS and HTS cables

The coupling current losses represent an essential contribution to AC losse s in most practical superconducting conductors. The origin of this loss typ e is well known, being caused by induced currents in different loops consis ting of superconducting and non-superconducting parts. However, the 'curren t pattern' in different conductor types (strands, flat or round cables, mor e complicated cable structures. CICC) varies appreciably. These differences are mainly due to geometrical effects (size and shape of filaments and/or strands, their spatial distribution, conductor aspect ratio, demagnetizatio n effects). Although the general knowledge about AC losses in low temperatu re cable structures is by far not complete (mainly at higher frequencies, i n inhomogeneous fields and for inhomogeneous cable structure), an attempt i s made to summarize those results which can be adopted to high T-c conducto rs and some remarks are made about new features of AC losses in these condu ctor types. (C) 1998 Published by Elsevier Science B.V. All rights reserved .