Division of accelerators, cryogenics and magnetism

We developed and tested the 25T cryogen-free superconducting magnet using high-Tc superconducting (HTS) insert.

The LTS and HTS magnets are cooled by two 4K-GM cryocoolers and two GM/JT cryocoolers, respectively.

The outsert magnet, which consists of high strength Nb3Sn and NbTi Rutherford cable coils, generates 14 T in a 300 mm bore.

We made RE123 and Bi2223 insert coils as the HTS insert. Finally we succeeded in the field generation of 24.6 T in a 52 room temperature bore, using the Bi2223 insert coil.

The design concept and test result including quench behavior will be introduced.