Observations of the effects of adsorbates on patch potentials

摘要: The authors report measurements of surface patch potential profiles on polycrystalline Cu and Au surfaces in high vacuum after previous exposure to air. These results are relevant experiments measure the gravitational acceleration charged particles inside vertical metallic drift tubes. Axial variations due potentials tube limit accuracy these experiments. They discuss problems non-uniform contamination by adsorbates, which generally produces patches over length scales larger than crystallite size. Their observations show that, given sufficient time, smoothed out, apparently preferential adsorption background contaminants.