Integrated Leak testing of 80 K Thermal Shields of SST-1 in room temperature and cold condition

SST-1 has implemented bubble type 80 K thermal shields cooled with single-phase liquid Nitrogen around the superconducting magnet system. These panels have been designed to maintain temperature uniformity within ⊥ 5 K with pressure drops below 1.5 bar for nominal flow conditions. Another extremely critical criterion towards the functionality of these thermal shields is the leak tightness of these panels under any normal and offnormal scenarios. Integrated helium leak testing on each of these panels as well as group of assembled panels both at room temperature (RT) as well as at cold temperature of 80 K have been carried out to ensure leak-tightness. All the panels have been tested in component levels before and after thermal shocks between RT and 80 K three times. As per defined groups, these assembled panels around SST-1 vacuum vessel modules and sectors have been tested inside a dedicated high vacuum (HV) chamber having vacuum < 5.0 × 10⁻⁵ mbar. The panel temperature was obtained to be 80 K with inlet pressure of 1.83 bar (a). Before cool down and after achieving 80 K, these panels were leak tested by pressurizing helium gas at 8.0 bar (g). RGA spectra does not show traces of helium gas indicating the leak tightness of integrated system.