The Large-scale Superconducting Feeder System Developed by ASIPP Completes the On-site Integration in GA

Recently, the large-scale superconducting feeder system developed by ASIPP for General Atomics (GA) Fusion National Laboratory for its ITER central solenoid coil testing completed the on-site integration, passed the acceptance test and achieved 48.5kA steady state operation, symbolizing the delivery of the goods from ASIPP to GA. 

The acceptance test of the superconducting feeder system is also the first integrated debugging and operation of the various subsystems required by US ITER CS coil 4K electrical performance test, including 50kA power system, 900W @ 4.5K cryogenic systems, high voltage isolation system and quench protection system. The system is complex, and the debugging is difficult. Through collaboration between the engineers of both sides, the completion of the test laid a solid foundation for the next CS coil cold test. 

Test results show that: Feeder system low temperature < 5K; thermal shield temperature < 90K; the 40 K mass flow rate of nominal current operation is ~0.064 g/s/kA, superior to the ITER design requirement of 0.071 g/s/kA; all of the 4 joint resistance < 0.6nΩ, meet the design requirement of 2nΩ; the65 K HTS joint resistance < 6nΩ, better than the design requirement of 10nΩ. 

The large superconducting feeder system was developed to test and control the whole process of coil operation. It provides the high-current, deep low temperature cold quality and control signals that the ITER center coil test requires, and it’s also responsible for coil energy release and cryogenic system protection. 

The system is 10.5 meters long and 4.5 meters high, weighing about 30 tons. It comprises a pair of high-temperature superconducting (HTS) current leads, a coil terminal box, and a superconducting transmission line system. The entire project involves multiple disciplines like mechanical, electromagnetic, monitoring and control, low temperature, vacuum and superconductivity. (Qingqing DU reports) 

GA Feeder 48.5 kA steady state operation

Large-scale superconducting feeder system developed by ASIPP

Site acceptance test Group Photo at GA