The Study Of Cable-Around-Conduit Conductor Superconducting Joints

Superconducting cable joint is one of the key components of superconducting magnets, where performance directly affects the quench Current recession and stability of the cable. In this dissertation the joints for CACC(Cable-Around-Conduit Conductor), have been designed and developed, which will be applied for the project proposed by Institute of Modern physics HIAF(High Intensity heavy ion Accelerator Facility).The objective of this study is to provide reliable joints with low losses for the HIAF superconducting magnets. This thesis expatiate from four aspects:1. The characteristics and application status of three types superconducting cables and their joints technology are summarized. Based on this study the goals of the research are determined, firstly keeping the Current uniformly in the strands of the cable joints, and secondly controlling the overall resistance effectively. The importance and significance of the research and development for CACC are also elaborated.2. The numerical simulation is performed to study the electric magnetic properties of joints. Effect of different parameters, such as the joint axis distance, length, width, height and orientation have been investigated. Based on the simulation results, the influence of each variable on joint performance have been analyzed and some basic guardingprinciples for making joints are established.3.Based on the characteristics of CACC, different joints for HIAF dipole magnets were designed. The features and feasibility for these joints are then discussed. The solder material and the soldering technology for first batch of samples are determined. Samples of various joints were made. The soldering effect, quality control and feasibility of the different joints are also discussed, considering the fabrication requirements.4.Varieties of measuring methods for superconducting joints were studied and compared, including their traits, scope and feasibility. Based on Current condition the appropriate measurements were selected and the preliminary Current tests were also made.