Design and Analysis of liquid nitrogen cooled sorption cryopump for SST-1 Tokamak

•Design of SST-1 cryopump for 250 deg. celsius bake-out temperature•Thermal analysis of panels with or without shield•Structural analysis of different components•Thermal analysis of panels and baffles at different bake-out temperature SST-1 is a Steady State Superconducting Tokamak for a proposed plasma discharge of long duration. This plasma device has two vacuum vessels, the cryostat and the vacuum vessel (VV). Cryostat houses the superconducting magnet systems (TF and PF coils), LN2 cooled thermal shields and hydraulics for these circuits and the plasma will be confined inside the VV [1]. To have plasma discharges, ultra-high vacuum (UHV) is required to be maintained in VV [2]. To attain a vacuum level of ∼1 × 10-8 mbar in VV, the plasma-facing components (PFCs) are baked to a temperature of 250 °C and the vacuum vessel is baked to a temperature of 150 °C to remove impurities from the bulk of materials which are adsorbed/absorbed. In baking, the gas load of mainly water vapour and hydrogen gas is increased. The pumping system for vacuum vessel consists of six sets of turbo-molecular pumps (each set consist of 3 TMP) and one cryopump which is sufficient to achieve a vacuum of