Regensburg 2000 – wissenschaftliches Programm
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VA: Vakuumphysik und Vakuumtechnik
VA 6: Ausgasung und Oberfl
ächen
VA 6.4: Vortrag
Dienstag, 28. März 2000, 16:00–16:20, H\"orsaal 47
Effect of readsorption in a dynamic vacuum system — •Petr Repa1, Ladislav Peksa1, Tomas Gronych1, and Jiri Tesar2 — 1Charles University Prague, V Holsovickach 2, 18000 Praha 8, Czech rep. — 2Czech Metrological Institute,Okruzni 31, 63800 Brno, Czech Rep.
An analysis of the pressure variations in vacuum chambers considering desorption and adsorption showed that the time-pressure curves should be modified by readsorption of the gases penetrating through or releasing from the walls. Nevertheless an apparent absence of any readsorption was observed in some measurements of the pressure-rise curves in sealed-off vacuum systems recently and the fact have not been explained entirely. In the presented study, an effect of readsorption on pressure variations was measured in a dynamic vacuum system. An apparatus for outgassing measurements described previously was used during the measurements. Doses of various gases (H2, CO, and H2O) were introduced into an uhv chamber of the apparatus which was simultaneously pumped by constant pumping speed. In the course of the measurements, the total and partial pressure vs. time curves were recorded at various pumping speeds. An analysis of the results implied that influence of readsorption on the pressure courses in dynamic systems is immeasurable small as well.