Rebuilding of the HT-7 TF coil current leads

The paper presents technical schemes and technological methods on the reconstruction of HT-7 current leads unit to satisfy physics requirements. At first, structure characteristics and design parameters on the current leads are described. The comparison between the former leads and the new ones is made. Secondly, fabricating steps necessary to reconstruct the leads and a series of technological methods to solve the techniques are reported. Then, based on the stress analysis and mechanical properties at low temperature on some kinds of materials used in LHe system, the stress weak links and improvement methods are discussed. Finally, the vacuum test and status of LHe system including the current leads after rebuilding are given.