Enhanced removal of X-ray-induced carbon contamination using radio-frequency Ar/H₂ plasma

Removal of X-ray-induced carbon contamination on beamline optics was studied using radio-frequency plasma with an argon/hydrogen (Ar/H₂) mixture. Experiments demonstrated that the carbon removal rate with Ar/H₂ plasma was higher than that with pure hydrogen or argon. The possible mechanism for this enhanced removal was discussed. The key working parameters for Ar/H₂ plasma removal were determined, including the optimal vacuum pressure, gas mixing ratio, and source power. The optimal process was performed on a carbon-coated multilayer, and the reflectivity was recovered.