Experts of the Fraunhofer IST explain fundamentals and specialized questions, among other things from the field of thin film technology. 

  • How is actually vacuum generated? – Part 2

    Answers from Prof. Dr. Günter Bräuer / 21.6.2019

    © Fraunhofer IST

    ”Wind is air which is in a hurry.” In the Earth's atmosphere, airstreams flow from high-pressure areas to low-pressure areas. We experience them as winds, storms or hurricanes. The Coriolis force forms them into vortices.

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  • How is actually vacuum generated?

    Answers from Prof. Dr. Günter Bräuer / 18.12.2018

    In-situ diagnostics and model-based control of in-line magnetron sputtering processes for large-area coating.
    © Fraunhofer IST, Rainer Meier, BFF Wittmar

    It is trivial: To remove gases from a given volume we have to pump. We know this from pumping of liquids. However, there are fundamental differences between pumping of liquids and pumping of gases. Liquids are incompressible, at constant temperature they don’t change their volume even if highest pressures are applied. This principle is used in hydraulic power transmission.

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  • What is actually ”vacuum”?

    Answers from Prof. Dr. Günter Bräuer / 14.9.2018

    Prof. Dr. Günter Bräuer, Director of Fraunhofer IST.
    © Fraunhofer IST, Florian Kleinschmidt,

    At Leybold-Heraeus, at that time a market leader in vacuum plant construction, I learned the following ambiguous statement: “We’ve got a vacuum in our heads!” The ancient Greeks had already been involved with vacuums in around 500 BC. In order to make use of the vacuum technically, for instance to deposit high-quality thin films, we definitely need matter as well as electrical and magnetic fields, and, depending on the circumstances, radiation too. We use highly rarefied gases to operate low-pressure plasmas, which in turn serve as an energy source during the depositing of coatings. Nowadays, physicists define a vacuum strictly as a space containing neither matter, radiation nor force fields.

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