Recent advances in assembly and commissioning of the steady state superconducting tokamak SST-1

SST-1 is a medium sized, large aspect ratio superconducting tokamak, which is under construction in India. It is designed for plasma discharge duration of ∼1000 seconds and configured to run double , diverted plasma. It has a major radius of 1.1 m with plasma minor radius of 0.2 m, with maximum toroidal magnetic field of 3 tesla at the plasma center. The mission of the SST-1 project is to address physics and engineering issues related to steady state tokamak operation. Significant progress has been made in the construction of the SST-1. Most of the components of SST-1 are manufactured, tested and available at site, for assembly. Machine support structure and cold mass support structure along with its cryogen connections are assembled and tested. Extensive ground preparation work including functional and qualification tests for major components is nearly at completion stage. Critical dimensions are measured using ECDS (Electronic Coordinate Determination Systems). Major cryogen connections are made using orbital TIG welding process. Ground preparation for vacuum vessel modules along with liquid nitrogen shield is in progress. Ground preparation like inter-pancake joints, cryogen connections etc. are made for most of super-conducting magnets. All the duly tested copper magnets are ready for the assembly. Assembly of a pair of TF superconducting coils along with vacuum vessel module is being done. This paper presents the detailed description of major progress made in the SST-1 assembly. It also details about underpinning ground preparation work and details about methodology to be followed for completion of the remaining work and final testing and commissioning plan of SST-1 machine.