NEG PUMP FEATURES
Taken from reference [1]:
In general, getter materials are classified in two different categories: the evaporable and non evaporable getters. In the first category, the alloys are mainly based on barium and titanium atoms which are released by an evaporation process to form a thin getter film. In the case of NEG, no evaporation is required. Getter materials are generally made of zirconium or titanium, which are configured in a high efficiency getter cartridge structure. NEG pumps have been developed in the 70’s and since then they have been widely used by the industry, R&D labs, research centers and large physics projects like accelerators, synchrotrons or fusion reactors. They are used in combination with other pumps, like SIP or TMP, to improve the final vacuum or reduce the pump down time in a system or to remove contaminants which cannot be pumped by other pumps. They generally operate in the 10 -7 -10 -13 mbar range and present several very unique features:
• Pumping speed is unaffected down to <10 -10 mbar, differently from SIP which loose pumping speed already in the 10 -8 -10 -9 mbar range.
• NEG pumps remove very efficiently the hydrogen, the main residual gas in UHV baked out and not leaking systems, in terms of high pumping speed and sorption capacity.
• NEG pumps have also important pumping properties for the other active gases that are comparable or even better the performances of the other UHV pumps.
• NEG pumps do not require any power supply during gas adsorption (power in the order of tens watts are used to reactivate the NEG pumps).
• They are oil-free and vibration-free, ideally suited for clean systems where contamination and mechanical disturbances are an issue.
• They are much more compact and lighter than any other type of pumps, considering equal pumping speed.
• They operate unaffected by magnetic fields and do not generate magnetic fields.
• They pump some heavy hydrocarbons and organic molecules.
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