General Physics Seminar Thursday 5 September 2002

Research on Superconductors for Nuclear Fusion

Bennie ten Haken and Arend Nijhuis

University of Twente, Applied Physics dept.
Enschede, The Netherlands


Superconducting magnets are a crucial element in many plasma research facilities for nuclear fusion. The large and rapidly changing magnetic fields that occur in these machines has stimulated the development of so-called low-Tc superconductors as NbTi and Nb3Sn. A typical aspect in this application is that the conductor is used in very large cables (typically with 1000 s.c. wires) placed in a steel reinforcement.

The UT Low temperatures group contributed to this R&D by studying the maximum current at high-fields, the energy loss due to AC-fields and the strain sensitivity of these conductors.

In this presentation a short review is given about the superconductors that are used in fusion related research and the other superconductors that are developed for other applications as particle accelerators, NMR/MRI systems and energy transmission.

Additionally some recent issues in the development of s.c. cables for fusion are considered:
- AC Loss and stability in cable in conduit conductors,
- Transverse forces in cabled Nb3Sn conductors,
- Test results of ITER relevant model coils.
Finally we will draw some conclusion about the important issues for the further development of superconductors for fusion and the application of these conductors in a large scale demonstrator on a relatively short term.