Study on HTS/LTS hybrid superconducting central solenoid for fusion device

Nb3Sn is considered to be one of the best candidate low temperature superconducting materials for the fusion superconducting magnet system. However, in consideration of the optimization design work of fusion device magnet system, higher volt seconds under a presupposition of a much more economical device size needs to be achieved. In our recent work, a type of HTS/LTS hybrid magnet has been designed for the central solenoid for fusion device. It can provide a maximum volt seconds of 200 V.S with the maximum magnetic field of 19.4 T. The inner HTS part of the magnet is designed with Bi-2212 conductor while the outer LTS part is designed with Nb3Sn conductor. It can meet the requirements of high magnetic field and operation current for fusion device. The structure design of HTS/LTS hybrid magnet has been carried out. Besides, variation of electromagnetic properties according to the flexible structure design of HTS/LTS hybrid magnet and related stability analysis work are also illustrated in this paper.