04 August 2020
The National Nuclear Center of RK has completed welding of lid flange joints and equatorial tubes to cylinder of the vacuum chamber at KTM tokamak. Therefore, conditions for the chamber sealing are provided under heating up to the temperature required for qualitative vacuum chamber cleaning, necessary for better plasma parameters.
Following the work completion, chamber leakage test was conducted under operational conditions – heating up to 190 °C. Comparative analysis of sealed vacuum chamber mass-spectrum and spectra recorded during final stage of physical start-up in 2019 proved there is no observed deterioration of gas composition indicating inleakage from atmosphere. After the vacuum chamber cooling down to 45 °С, leakage survey using helium blow-off with mass-spectrometer ExTorr 200M detected no leakages.
The completed effort will enable to increase heating temperature of the vacuum chamber from 130°С, applied during physical start-up, to 190°C, that improves quality of vacuum conditions having positive effect to plasma parameters.