The 5 K Heat Load Test of GA Feeder for ITER CS Magnet Test Application

The GA Feeder is a superconducting feeder system, which connects from the Room Temperature (RT) power supply system to the 4.5 K busbar of the magnet, used for Iter Central Solenoid magnet test at General Atomics Company in U.S.A. This system is make up of 3 parts: Coil Terminal Box (CTB), Feeder duct (FD), In Chamber Feeder-through (ICF), containing a pair of 52 kA High Temperature Current leads (HTSCL), thermal shield, busbars, joint boxes, pipes and other components. It has been developed and cold tested at the Institute of Plasma Physics, Chinese Academy of Sciences, and the 5K heat load test was performed in Dec. 2015. The requirement of overall heat load 68 W is a big challenge, and many efforts were took to achieve the required value, such as reduce the inlet pressure of the whole system as much as possible, minimize the flow rate of different cooling circuits, a dedicated program was developed to online calculated the density and the heat load to help analyzing the heat load of the system. This paper will present the 5K heat load measurement of this system.