| AVS 63rd International Symposium & Exhibition | |
| Vacuum Technology | Tuesday Sessions |
| Session VT-TuA |
| Session: | Accelerator and Large Vacuum Systems |
| Presenter: | Paolo Manini, SAES Getters S.p.A., Italy |
| Authors: | P. Manini, SAES Getters S.p.A., Italy M. Puro, SAES Getters S.p.A., Italy S. Raimondi, SAES Getters S.p.A., Italy T. Porcelli, SAES Getters S.p.A., Italy F. Siviero, SAES Getters S.p.A., Italy E. Maccallini, SAES Getters S.p.A., Italy G. Bongiorno, SAES Getters S.p.A., Italy |
| Correspondent: | Click to Email |
Non-evaporable getter (NEG) coatings are nowadays successfully employed in several accelerator facilities, where stringent ultra-high vacuum (UHV) conditions should be met.
NEG coatings are able to provide high distributed pumping speeds for every getterable gas; in addition, the thermal outgassing and secondary electron yield of a NEG-coated beam pipe are considerably reduced, thus allowing the achievement of better results in terms of base pressure and, consequently, beam lifetime and luminosity.
The use of NEG coatings is especially suitable for narrow-gap beam pipes and insertion devices, which could not otherwise be pumped with the same effectiveness by a series of traditional UHV lump pumps. This aspect is particularly significant in view of next-generation machines, for which long and small-aperture tubes (i.e., down to 4 mm) are envisaged in order to reach even higher luminosities and lower emittances.
Such stringent requirements should be carefully addressed, as a number of technical issues arise—both in terms of coating deposition and characterisation—when dealing with narrow-gap beam pipes of this kind.
SAES’ recent achievements in this field are here presented, together with an overview of the ongoing R&D activities, whose aim is to demonstrate the feasibility and pumping effectiveness of narrow pipes under 10 mm of diameter. These include SEM morphological inspections, chemical composition analyses and thickness profiling made by EDX and, finally, measurements of the getter film’s sorption capacity for CO. Future perspectives and issues—including the possibility to coat very long and narrow chambers and to perform transmission factor measurements on them—are also reviewed.