Works to Ensure Tightness of the Vacuum Chamber of the KTM Tokamak

In order to ensure the conditions for the tightness of the vacuum chamber (VC) of the KTM Tokamak when heating up to a temperature that provides high-quality purification of the VC, required to obtain higher plasma parameters, flange joints of the VC lid and equatorial pipes have been welded with the cylindrical part (shell) of the VC.

  After the welding was completed, the tightness of the KTM VC was checked in operating conditions – heating up to 190 °С.

Comparative mass spectrum analysis of the welded VC and the spectra taken during the final stage of the physical start-up (PS) carried out in 2019 showed that there is no deterioration in gas composition corresponding to leakage from the atmosphere.

After the VC was cooled to a temperature of 45 °C, a search for leaks was carried out by blowing the VC with helium using an ExTorr 200M mass spectrometer, leaks were not detected.

The performed work will allow increasing the heating temperature of the KTM VC from 130 °С, applied at the PS, to 190 °С, which will improve the vacuum condition quality that have a positive effect on the plasma parameters.