A cryopump is a type of vacuum pump that traps gases or vapours by condensing them on a super cooled surface - a cold bathroom mirror uses a similar principal to condense the vapour from a hot tap. They are typically used in applications where specific gases or vapours need to be removed from a supply, and the supply made ‘clean’ before it can be used, such as within the semiconductor, electronics, optical coatings and medical device industries.
Typically, the overall performance of cryopumps is evaluated by the pumping speed (the rate at which vapours can be removed). Generally speaking, the larger the cooled surface (cryocoil) surface area, the greater the pumping speed. High performance cryopumps therefore tend to be larger in overall size.
Cryopumps are not entirely continuous as, at regular cycles, it will ‘regenerate’, whereby the trapped gases or vapours are warmed and converted back to their original state, where they can then be extinguished.
Due to the lack of moving parts within a cryopump, they are vibration-free, relatively insensitive to contaminants and chemical reactions, whilst typically extremely hard wearing and reliable over years of continued service.