A 15-T ReBCO Insert for a 30-T All Superconducting Magnet

At the Instititue of Electrical Engineering of the Chinese Academy of Sciences, a central field of up to 24 T was achieved with a ReBCO insert in a 15-T LTS magnet at 4.2 K. The reali-zation of a 24-T magnetic field with an all superconducting magnet makes our program more ambitious. A 30-T all superconducting magnet program composed of a 15-T 35-mm ReBCO insert and a 15-T LTS background magnet is our next goal. The design of the insert is performed first in this paper. The 15-T insert consists of two stacks of ReBCO double pancake coils connected in series. The operation current is designed as 123.5 A, and the operation margins for these two ReBCO coils are both 53%, which is a good approach to improve the operation stability of the insert. Stress analysis is also performed. Methods to improve poor cooling conditions are presented in this paper for regions where helium bubbles are trapped due to the diamagnetic susceptibility of helium. New technologies for fabricating a high-field ReBCO insert with a solid structure are introduced. A multichannel data acquisition system for high-field insert research is under construction. This program is planned to be finished and tested in 2017.