On the Ability of Freon (trademark) C-318 to Trap Hydrogen on a 77 K Cryosurface

Abstract

Studies of the trapping of hydrogen and helium by condensing Freon C- 318 (C4F8) on a 77K surface have indicated that no pumping of the gases occurred. Freon was added to a predominately hydrogen atmosphere at rates from 1.52 x 10 to the -3rd to 0.73 torr-liters/sec with no change recorded in the partial pressure of hydrogen. A similar experiment was made with helium and no pumping was noted. It was observed that the mass spectrometer indicated a significant reduction in the partial pressure of hydrogen when the total pressure in the chamber increased to the 0.0001 to 0.001 torr range. It was shown that this was not due to hydrogen pumping but to internal scattering and resulting nonlinearity of the mass spectrometer in this pressure range.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1971
Accession Number
AD0730271

Entities

People

  • Jerry Coble
  • Ronald Dawbarn

Organizations

  • Arnold Engineering Development Complex

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Calibration
  • Chambers
  • Diffusion Pumps
  • Elements
  • Gages
  • Instrumentation
  • Ionization Gages
  • Mass Spectrometers
  • Measurement
  • Measuring Instruments
  • Partial Pressure
  • Spectrometers
  • Test Facilities
  • Vacuum
  • Vacuum Chambers
  • Vapor Pressure

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Plasma Physics.