Design and Manufacture of Full-Size Testing Joints for EAST

【摘要】 <正> The conductors of both the toroidal field (TF) and poloidal field (PF) coils of EAST are NiTi cable-in-conduit conductors (CICCs). The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm~18.5 mm respectively. A relevant R&D program has been carried out for three years at the Research and Manufacture Center (RMC) of the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals’ super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape.Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ. The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.更多还原

【Abstract】 The conductors of both the toroidal field (TF) and poloidal field (PF) coils of EAST are NiTi cable-in-conduit conductors (CICCs). The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm~18.5 mm respectively. A relevant R&D program has been carried out for three years at the Research and Manufacture Center (RMC) of the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals’ super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ. The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.更多还原