Wall Pumping and Hydrogen Recycling in TEXTOR 94

摘要

The pumping of hydrogen by the TEXTOR, vessel walls during ohmic discharges and the subsequent hydrogen release between discharges have been studied at wall temperatures between 150 deg C and 350 deg C, At the beginning of a discharge the vessel walls show a high, but transient wall pumping speed which decreases as the discharge proceeds. At the end of a discharge the wall pumping speed tends towards a steady state value of about 1 x 10~(20) hydrogen atoms/s. Hydrogen outgasing after discharges follows a power law propor.to t~(-0.7).