Monday, July 11, 2016
ABSTRACT: The recent activities of the ENEA Superconductivity Group on High Temperature Supercondutors (HTS) will be shortly reviewed emphasizing projects related to Fusion. In particular, the ENEA Superconductivity Laboratory has been working for decades on the development of Low Temperature Superconducotrs (LTS) Cable-in-Conduit conductors, especially for nuclear fusion magnets. However, HTS materials can now be considered as a mature technology, and the use of them should be implemented also in such systems. For this reason, ENEA has recently developed, together with its industrial partner TRATOS Cavi, a full size cable-in-conduit conductor (CICC) based on HTS 2G tapes. A manufacturing process has been developed, fully compatible with existing cabling technologies, to be readily transferred to an industrial scale production. Inspired by the stacked tape concept proposed by MIT group, the design is constituted of 5 stacks of 20-30 tapes each (depending on the tape thickness), inserted into a properly slotted and twisted core of Aluminum, with a central pressure relief channel for Helium circulation. The cable is wrapped with stainless steel tape and compacted inside a jacket, thus fully reproducing the structure of a typical CICC for fusion applications. As a reference performance value, the design was conceived for a transport current of 20 kA at 4.2 K and 12 T. Results of the preliminary qualification tests will be presented and discussed such as the bending experiments carried out at MIT PSFC.
The main aspects related to the concept of CICCs are summarized here, and the prospects of solutions based on HTS materials are discussed.