Implementation and analysis of ITER strand test of CNDA for world-wide benchmarking

According to the International Thermonuclear Experimental Reactor (ITER) Procurement Arrangement (PA) of Cable-In-Conduit Conductor unit lengths for the magnet systems, at the start of process qualification, the Domestic Agency (DA) shall be required to conduct a benchmarking of the room and low temperature acceptance tests carried out at the strand suppliers and/or at its reference laboratories designated by the ITER Organization (IO). The first benchmarking was carried out successfully in 2009 and the second round in 2010. Bronze-Route (BR) Nb3Sn strand and samples prepared by CERN were sent out to each participant in the first round. The second round was referred to the Internal-Tin(IT) Nb3Sn and NbTi strand. The two rounds of benchmarking included tests for critical current, hysteresis loss, residual resistance ratio, strand diameter, Cu fraction, twist pitch, and plating thickness. As the referenced lab of Chinese DA (CNDA), the superconducting strand test lab from Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) participated in the Benchmarking. The feedback from IO showed good results and high coherence. The test facility and test results for benchmarking of CNDA were presented in this paper.

► The activities of CNDA for superconducting strand benchmarking were summarized.
► Details of the tests facility and process were described and analyzed.
► The test items include room temperature and low temperature measurements.
► The results of the two round benchmarking were shown and the deviation of each item was summarized.