- "Ion pump" redirects here. For a protein that moves ions across a plasma membrane, see Ion transporter.
An ion pump (also referred to as a sputter ion pump) is a type of vacuum pump capable of reaching up to 10-11 mbar under ideal conditions.[1] An ion pump ionizes gases and employs a strong electric field, typically 3kV to 7kV, to accelerate them into a solid electrode. A swirling cloud of electrons produced in hollow Penning cells ionizes incoming gas atoms and molecules while they are trapped in a strong magnetic field. The swirling ions strike the chemically active cathode inducing sputter and are then pumped by chemisorption which effectively removes them from the vacuum chamber, resulting a net pumping action. Inert and lighter gases, such as He and H2 do not effectively induce sputter and are absorbed by physisorption. Some fraction of the energetic gas ions (including gas that is not chemically active with the cathode material) that strike the metal cathode steal an electron from the surface and rebound as a neutral atom. These energetic neutrals are reflected back from the cathodes and buried as neutrals in exposed pump surfaces. [2]
There are three main types, the conventional or standard diode pump, the noble diode pump and the triode pump[3].
Ion pumps are commonly used in ultra high vacuum (UHV) systems, as they can attain ultimate pressures less than 10-11 mbar.[4] In contrast to other common vacuum pumps such as turbomolecular pumps and diffusion pumps, ion pumps have no moving parts and use no oil and are therefore very clean and low-maintenance.
Not to be confused with the ionic liquid piston pump or the ionic liquid ring vacuum pump.
References
- ^ http://www.varianinc.com/image/vimage/docs/products/vacuum/pumps/ion/shared/ion-catalog.pdf
- ^ Moore, J.H.; Davis, C. C.; Coplan, M.A.; Greer, S. (2003). Building Scientific Apparatus. Westview Press. ISBN 0813340063.
- ^ The pumping of helium and hydrogen by sputter- ion pumps part II
- ^ "Ion Pumps" (PDF). Varian, Inc.. http://www.varianinc.com/image/vimage/docs/products/vacuum/pumps/ion/shared/ion-catalog.pdf.
Sources
- Hablanian, Marsbed. "Gettering and Ion Pumping". High-Vacuum Technology: A Practical Guide (ISBN 082478197X). http://www.aiv.it/ITA/pubblicazioni/articolo.php?articolo=art4.
- "Sputter Ion Pumps" (PDF). Paul Scherrer Institute. http://www.chem.elte.hu/departments/altkem/vakuumtechnika/CERN03.pdf.
External links
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