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Vacuum pump

A device for pumping air out of an enclosed area to create a vacuum inside it. There are many types of vacuum pumps used depending on the area from which the gas is drawn and the vacuum to be achieved. The most widely used is the rotary pump, which uses rotating blades to draw air from the evacuated area. A turbomolecular pump requires high vacuum at the inlet and is used to achieve an ultra-high vacuum. With a set of very rapidly rotating blades, it transfers kinetic energy to the remaining gas molecules so that they are “kicked” out of the area. The cryopump uses a highly porous material (zeolite, charcoal) cooled to very low temperatures. The gas molecules condense on the cool surface and are thus removed from the space. Over time, the adsorbent becomes saturated and the pump must be regenerated by simply heating it out of the evacuated space, releasing the gases. Many processes require a good vacuum and hence the use of vacuum pumps. For example, the interior of a vacuum chamber used for thermonuclear fusion research must contain a high vacuum.