Regensburg 2025 – scientific programme
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O: Fachverband Oberflächenphysik
O 66: Vacuum Science Technology: Theory and Applications
O 66.2: Invited Talk
Wednesday, March 19, 2025, 15:30–16:00, H8
Advances in traceable vacuum and outgassing rate measurements — •Matthias Bernien1, Annas Bin Ali1, Thomas Bock1, Tom Rubin1, Janez Setina2, Perrin Waldock3, Kirk Madison3, and Karl Jousten1 — 1PTB, Abbestr. 2-12, 10587 Berlin — 2IMT, Lepi pot 11, 1000 Ljubljana, Slovenia — 3University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1, Canada
For the pressure range from 10 mPa to 130 Pa, a fully automated static expansion system made of aluminum has been set up and validated. Its principle involves transferring a fixed amount of gas from a smaller volume to a larger one, creating a well-defined lower pressure, provided that the initial pressure and the volume ratio are accurately known. Relative standard measurement uncertainties between 0.08% and 0.012% are achieved. Primary standards utilizing cold atom traps offer a promising new approach for realizing the pascal in the UHV range by measuring the loss rate caused by collisions with gas molecules. To establish these standards, the University of British Columbia and PTB have carried out a comparison between a mobile standard based on cold atoms and a continuous expansion system for N2, Ar and H2. In the semiconductor industry, outgassing from components in vacuum must be well controlled. Contaminants are monitored using QMSs which lack stability. This is particularly problematic when maximum levels of contaminants must be agreed between manufacturers and suppliers. To improve the comparability of outgassing rate measurements, reference samples for dodecane and water have been developed suitable for in-situ calibration of QMSs.
Keywords: vacuum; metrology; outgassing; cold atoms