Solder Development and Fabrication Techniques for Coolant Tube Bonding in Lengthy High Current Conductors

摘要

The National Spherical Torus Experiment (NSTX) is being enhanced to significantly expand plasma conditions that are essential for next step Spherical Torus (ST) development. Improvements to this leading, high performance ST include doubling the magnetic toroidal field (TF) and plasma current with a tenfold increase to the plasma discharge duration. This requires a Center Stack Upgrade (CSU) with double the current capability of the TF inner conductors. Bonding water cooling tubes in these new TF Conductors required developing nonionic solder flux and controlled, repeatable heating.