加速器用の極低温実用表面における水素吸着 Adsorption and Desorption Measurements of Hydrogen on Technical Surfaces for Accelerator Use
Saturation coverages and adsorption energies of hydrogen molecules adsorbed at 4.2 K were investigated for several technical surfaces of an anodized aluminum, an electroplated copper coating and a sputtered TiZrV coating. From the result of adsorption isotherm measurements, the adsorbing molecules amount saturates in one monolayer, or two, on the smooth surfaces of the Cu and TiZrV coatings, while the adsorption capacity in the porous surface of the anodized aluminum is several tens times large. Thermal desorption spectra show the peak corresponding to the adsorption energy of about 20 meV for all the materials. In the anodized aluminum surface, when cleaned by baking, the additional sites with higher adsorption energies of 70 and 80 meV are observed. Hydrogen molecules adsorbs first in these sites, then forming an adlayer with the adsorption energy of 20 meV.
真空 43(4), 499-503, 2000-04-20
The Vacuum Society of Japan