Various Methods of Reducing AC Losses and Improving Stability of Internal‐Tin Nb3Sn Superconductors

In the past much of the emphasis in the development of Nb3Sn superconductors for High Energy Physics has been on improving the non‐Cu critical current density, (Jc), at 12 T. More recently the focus has shifted to improving the matrix residual resistivity ratio, (RRR), and decreasing the ac losses. In addition, the field of interest has risen to the 15–18 T range. Piece length and cost are also factors that are assumed not to deteriorate as the other properties are improved. In this paper we have emphasized reduction of losses by changing the conductor design. This has been explored both by the introduction of fins of various types and also by simply increasing the number of subelements using a tubular process, which has the potential of a low cost approach. The effect of these changes on the ease with which the multi‐subelementary material can be made is explored and discussed.