Accession Number : AD0461132


Title :   CONSIDERATIONS IN THE MEASUREMENTS OF CRYOPUMPING CAPTURE COEFFICIENTS


Corporate Author : ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN


Personal Author(s) : Haygood, J D ; Dawson, J P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/461132.pdf


Report Date : Apr 1965


Pagination or Media Count : 31


Abstract : A survey is presented of the more important practical and theoretical relationships involved in the study of cryopumping. Starting with a rigorous definition of the capture coefficient, the effects of temperature on the measured values are derived. Several practical points in the design of a chamber for cryopumping measurements are given, including cryosurface and gage placement, calibration, effects of outgassing and impurities, and temperature measurements.


Descriptors :   *CRYOPUMPING , CRYOGENICS , DEGASIFICATION , IMPURITIES , INSTRUMENTATION , MEASUREMENT , TEMPERATURE , VACUUM , VAPOR PRESSURE


Subject Categories : Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE