Abstract
We studied on characteristics of the photon-stimulated desorption of water from a chamber wall and on its application to a quick pump-down of a vacuum system. Employing a mercury vapor lamp as a photon source, we measured the amount desorbing gas molecules (mainly H2O, H2, CO, and CO2) with a quadrupole mass analyzer in a titanium chamber and in a 304 stainless steel chamber for comparison. The orifice method allows the evaluation of the outgassing rate. After 1 hour of irradiation its value was reduced to the order of 10-7 Pa m3m-2s-1, irrespective of the wall materials.
