Nonevaporable getter coating chambers for extreme high vacuum

Journal Article · 01 March 2018 · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films

DOI: https://doi.org/10.1116/1.5010154 · OSTI ID:1439842

Stutzman, Marcy L. ^[1]; Adderley, Philip A. ^[1]; Mamun, Md Abdullah Al ^[1]; Poelker, Matt  ^[1]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Techniques for NEG coating a large diameter chamber are presented along with vacuum measurements in the chamber using several pumping configurations, with base pressure as low as 1.56x10^-12 Torr (N2 equivalent) with only a NEG coating and small ion pump. We then describe modifications to the NEG coating process to coat complex geometry chambers for ultra-cold atom trap experiments. Surface analysis of NEG coated samples are used to measure composition and morphology of the thin films. Finally, pressure measurements are compared for two NEG coated polarized electron source chambers: the 130 kV polarized electron source at Jefferson Lab and the upgraded 350 kV polarized 2 electron source, both of which are approaching or within the extreme high vacuum (XHV) range, defined as P<7.5x10^-13 Torr.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• Grant/Contract Number: AC05-06OR23177
• OSTI ID: 1439842
• Report Number(s): DOE/OR/23177--4377; JLAB--ACC-18-2671; arXiv:1803.07056
• Journal Information: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films Journal Issue: 3 Vol. 36; ISSN 0734-2101
• Publisher: American Vacuum SocietyCopyright Statement
• Country of Publication: United States
• Language: English