Abstract
Technological aspects and recent advances in the current leads incorporating high temperature superconductor (HTS) are described. HTS of sintered Bi-2223, melt cast Bi-2212, unidirectional Y-123 and Ag- or Ag alloy-sheethed Bi-2223 are being investigated and tested in models of current lead systems. Reduction of refrigerator power by a factor of 3 to 5 is demonstrated by model tests. Easy operation and a cryogen-free superconducting magnet has become available using HTS current leads. Researches concerning safety and reliability are being made, ac operation models are tested, and design studies for specific application in large systems are underway. We can expect that all of the Cu current leads will be replaced by HTS current leads.
