Abstract: Binary current lead is one of the key parts of superconducting electromagnet iron remover (SEIR) system. It mainly consists of a copper current lead at the upper end, an intermediate heat exchanger and a high temperature superconductor (HTS) current lead at the lower end. A 200A binary current lead with a central magnetic induction strength of 3T is designed. The heat leak of the current lead, the internal heat resistance of the exchanger and the welding resistance between HTS line and the copper matrix are measured and the transient temperature change of the current lead at a cryocooler breakdown or power failure is studied. Both the theoretical and experiment results show that the designed current lead can satisfy the performance requirement for the operation of superconducting electromagnet iron remover (SEIR) system.

Key words: SEIR system, Binary current lead, Heat leak, Heat resistance, Welding resistance, Transient temperature change