Conceptual design of a 20-kA current lead using forced-flow cooling and Ag-alloy-sheathed Bi-2223 high-temperature superconductors

High-temperature superconductors (HTSs) consisting of Bi-2223 HTS tapes sheathed with Ag alloys are proposed for a 20-kA current lead for the planned stellarator WENDELSTEIN 7-X. Forced-flow He cooling is used, and 4-K He cooling of the whole lead, as well as 60-K He cooling of the copper part of the lead, is discussed. Power consumption and behavior in the event of loss of He flow are given.<
>