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Ultra high vacuum pumping system and high sensitivity helium leak detector

United States Patent

*** EXPIRED ***
December 30, 1997
View the Complete Patent at the US Patent & Trademark Office
Thomas Jefferson National Accelerator Facility - Visit the Technology Review Committee Website
An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10.sup.-13 atm cc s.sup.-1. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces backstreaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium.
Myneni; Ganapati Rao (Yorktown, VA)
Southeastern Univ. Research Assn. (Newport News, VA)
08/ 646,773
May 8, 1996
The United States may have certain rights to this invention under Management and Operating Contract DE-AC05-84ER40150 from the United States Department of Energy.