Design and Test of an 8T Focusing Superconducting Solenoid of FRIB Driver Linac

The Facility for Rare Isotope Beams (FRIB) was funded by the U.S. Department of Energy, which is the world’s most powerful isotope beam device. We have developed an 8T superconducting solenoid magnet which is used to focus and steer the heavy ion beams for FRIB Driver Linac. The solenoid consists of a main focusing coil, two shielding coils and two pairs of corrector dipoles, fabricated by NbTi wire only. A helium vessel was designed and fabricated to accommodate the coils with an entire length of 652 mm with end flange. The magnet in an operating current of 89.6 A achieved the maximum magnetic field of 8T in 40-mm cold bore without quench. In this paper, the overall design of the whole magnet was introduced, including the magnetic design, mechanical design, quench simulation and the protection circuit. Moreover, the winding process and the test results were showed.