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.
High Field Laboratory for Superconducting Materials, Institute for Materials Research, TOHOKU UNIV