Multistage cryogenic pump - has several vacuum regions all, cooled by a single refrigerating device

摘要

Multiple stage cryogenic pump for transferring matter, e.g. ions or a strip of material to be treated, between a gas and a vacuum chamber has an orifice in the vacuum chamber through which some of the gas leaks into the chamber. The chamber is divided into several regions by internal divider(s) each having an aperture through which the matter travels. The interior surface of the chamber is cooled by a single refrigerating device to below the condensn. temp. of the gas to establish different sub-atmospheric pressures in each region. The device is used for transferring ions into a vacuum for analysis by a mass spectrometer. The spectrometer is located in an operating region, which is the highest vacuum region, and the gas is pumped to successively lower pressures in a series of stages between the inlet and the operating region. It can also be u sed for vacuum deposition of metal onto a metal or plastics strip.