Mass Spectrometric control of the process of cleaning and degassing of protective graphite tiles of the Globus-M2 tokamak

Using a specially designed time-of-flight mass reflectron with a heating element inside the device, which makes it possible to heat solid samples and analyze the gases released from them, protective graphite tiles covering almost the entire plasma-facing surface of the Globus-M2 tokamak vacuum chamber were studied. Mass spectrometric analysis made it possible to determine the composition of the released gases to estimate their quantities, and thus to quantitatively characterize the quality of cleaning and degassing of tiles. It is shown that as a result of the applied method for processing tiles, the content of the light hydrogen isotope – protium, water, carbon monoxide and dioxide decreased several times, and the content of deuterium and helium isotopes decreased almost to zero.