Capture Coefficients of Gases at 77°K

  • R. F. Brown
  • E. S. J. Wang
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 10)


The rate of impingement of molecules on a cryosurface for any gas in the free molecular region can be calculated from kinetic theory. However, the actual pumping speed must be measured experimentally since all the molecules that strike the cryosurface are not captured. This effect is described by the capture coefficient. The latter is defined as the ratio of the measured pumping speed to the theoretical rate of strike.


Dipole Moment Impinge Molecule Methyl Chloride Ionization Gauge Condensation Phenomenon 
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Copyright information

© Plenum Press, New York 1965

Authors and Affiliations

  • R. F. Brown
    • 1
  • E. S. J. Wang
    • 1
  1. 1.Arnold Air Force StationARO, Inc.USA

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