First Engineering Validation Results of SST-1 TF Magnets System

Abstract

All SST-1 superconducting Toroidal Field (TF) and Poloidal Field (PF) magnets have been refurbished, integrated, and assembled onto the SST-1 machine shell in mid of 2012. Fabrication of sub nano-ohm, leak tight DC joints in superconducting magnets winding packs, enhancing the insulation strength in operating conditions, and test qualifying all the magnets prior to their integration in SST-1 machine shell were the primary refurbishment aspects. All assembled SST-1 TF magnets in SST-1 machine shell have since been successfully cooled down employing 1.3 kW SST-1 Helium Refrigerator/Liquefier system maintaining helium leak tightness under all temperature conditions. The TF magnets have experimentally demonstrated thermo-mechanical behavior as per the design as well as excellent flow uniformity amongst various parallel paths. Subsequently, these TF magnets have been increasingly charged so as to create a magnetic field of 1.5 T at the SST-1 major radius of 1.1 m. This is the first occasion, when cable-in-conduit wound toroidal field magnets have been successfully operating with two phase flow in a Tokamak application. The first plasma in SST-1 has been successfully obtained in June 2013 where the SST-1 TF magnets have demonstrated excellent functional characteristics. The confidence boosting engineering and functional validation test results of SST-1 TF magnets as well as its performance during the recent SST-1 plasma campaign have been elaborated in this paper.