Upgraded Cryogen-Free 20 T Superconducting Magnet

作者：Hanai Satoshi^*; Tsuchihashi Takahiro; Minemoto Yuji; Ioka Shigeru; Watanabe Kazuo; Awaji Satoshi; Oguro Hidetoshi

来源：IEEE Transactions on Applied Superconductivity, 2014, 24(3): 4301204.

DOI：10.1109/TASC.2013.2288923

• Bi2223 tape conductor
• cryogen-free magnet
• high magnetic field
• hoop stress
• hysteresis loss
• upgrade

We have constructed an 18 T superconducting magnet conductively cooled by a GM/JT (Gifford-McMahon/Joule-Thomson) cryocooler. A double-pancake stacked insert coil using Ag-sheathed Bi2Sr2Ca2Cu3O10 (Bi2223) tape with stainless steel reinforcement has generated 2.5 T in a 15.5 T outer LTS coil. After we constructed the cryogen-free 18 T superconducting magnet (18 T-CSM), Bi2223 tape conductors have been improved in both critical current and strength. The critical current of the conductor doubled and a tape conductor with copper alloy reinforcement which has a strength of 250 MPa at 77 K was developed. So we developed a new Bi2223 insert coil for the cryogen-free superconducting magnet which can generate 4.5 T in a 15.5 T outer LTS coil by exchanging the insert coil. The new 20 T cryogen-free superconducting magnet (20 T-CSM) can generate constant magnetic fields up to 20 T in a 52-mm room-temperature bore.

• 出版日期2014-6