Ohmic Heating Solenoid Design Utilizing Forced Cooled Windings

This paper discusses the feasibility of using NbTi internally cooled cable superconductor (ICCS) in the ohmic heating central solenoid for the fusion engineering device (FED). The ICCS conductor provides cryostable operation with liberal stability margin. The forced cooled concept has a high winding current density which reduces the size and the cost of the device. The forced cooled concept requires complex helium manifolding, but a unique approach has been developed to solve the problem. The conductor design, the winding design and the performance analyses are described. The solenoid is designed to operate at 8-T peak field and provides 60 MAT. The operating current for the solenoid is 21.3 kA, which is 60% of the critical current at 8 T.