Messung der Verweilzeit von He-Atomen an Glasoberflächen
- Cite this article as:
- Müller, D. Z. Physik (1965) 188: 326. doi:10.1007/BF01326948
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Mean sticking times of helium on a glass surface are determined at very low pressures from nonstationary molecular flow through glass capillaries. The temperature range covered is 13.8 °K to 20.4 °K.
Resulting sticking times are of the order of 10−7 to 10−5 sec. They show a characteristic dependence on temperature and pressure.
These measurements can be interpreted by means of a simple model: He-atoms mostly are bound to the surface with an adsorption energyE of 229 cal/mol≙0.01 eV (±20%). However with a probability of 10−4 the energy is 530 cal/mol≙0.023 eV (±6%). In both cases sticking times τ follow the equation τ=τ0exp(E/RT) where τ0 is about 10−9 to 10−10 sec.