A NbTi split magnet directly cooled by a cryocooler

A novel system consisting of a NbTi coil directly cooled by a G-M cryocooler was successfully constructed. The quench was simulated, focusing on the role of the copper bobbin as the secondary coil. Under the optimum conditions, a maximum field of 6.3 T was achieved. It was demonstrated that the critical current can be attained in the temperature range 6 approximately 9 K. After a quench the increment of the coil temperature was less than 50 K and safe operation of the system was demonstrated. The results indicate good possibilities for realization of a split magnet which produces a very high field.<>