Abstract
Conventional leak detectors are not useful for cold leak detection of LHe cooled cryogenic vacuum systems since He is adsorbed onto the cold walls. Even though the He desorption leak detection system1 developed at the Continuous Electron Beam Accelerator Facility (CEBAF) is very sensitive, the cryogenic system needs to be warmed up to at least 10.5 K for leak detection purposes, and it still would be impossible to identify the location of the leak. Recently hot cathode extractor gauges have been found to be reliable, very useful and convenient for very low pressure measurement (10-14 torr) at LHe temperatures. This paper discusses the operation of extractor gauges at LHe temperatures and their in situ use for fast and convenient cold leak detection of cryogenic vacuum systems. Further, the location and identification of the leaks based on the principle of the pressure wave travel of He and time-of-flight measurements of the He signal are also discussed.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
M.G. Rao, Helium Desorption Leak Detection Method, J. Vac. Sci. Technol. A 11, 1598 (1993).
M.G. Rao and P. Kneisel, The Use of Extractor Gauge at LHe Temperatures, CEB AF Tech Note #93-057, available from the Librarian, CEBAF, 12000 Jefferson Avenue, Newport News, VA 23606 USA.
M.G. Rao, Recent Advances in UHV Techniques for Particle Accelerators, CEBAF Tech Note #95-011, available from the Librarian, CEBAF, 12000 Jefferson Avenue, Newport News, VA 23606 USA.
J.G. Hengevoss, Gas Sorption by Surfaces Cooled to Low Temperatures, Trans. 3rd Int. Vac. Cong., Vol. 1, 51 (1965).
T.J. Lee, The condensation of H2 and D2: Astrophysics and Vacuum Technology, J. Vac. Sci. Technol. 9, 257 (1971).
J.P. Hobson and K. M. Welch, Time-Dependent Helium and Hydrogen Pressure Profiles in a Long, Cryogenically Cooled Tube, Pumped at Periodic Intervals, J. Vac. Sci.Technol. A 11, 1566 (1993).
M.G. Rao, P. Kneisel, and J. Susta, Cryosorption Pumping of H2 and He With Metals and Metal Oxides at 4.3 K, Cryogenics ICEC Supplement 34, 377 (1994).
M.G. Rao and W.C. Turner, to be published in J. Vac. Sci. Technol.
M.G. Kaganer, Proc. Acad. Sci. USSR Phys. Chem. Sect. 116, 603 (1957).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1996 Plenum Press, New York
About this chapter
Cite this chapter
Rao, M.G. (1996). Sensitive Helium Leak Detection in Cryogenic Vacuum Systems. In: Kittel, P. (eds) Advances in Cryogenic Engineering. A Cryogenic Engineering Conference Publication, vol 41. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-0373-2_224
Download citation
DOI: https://doi.org/10.1007/978-1-4613-0373-2_224
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-8022-1
Online ISBN: 978-1-4613-0373-2
eBook Packages: Springer Book Archive