The Use of Ion Probes in Re-Entry Physics

Abstract

Classical (Langmuir) probe theory is reviewed and the conditions under which it is applicable to the re-entry physics problem identified. Some later developments in probe theory, which account for flow velocity in the free- molecular case, are presented. Measurements of current densities have been made with ion probes mounted flush in the walls of a pressure-driven shock tube; the results are interpreted using a one-dimensional, collision-dominated probe theory, allowing for the spatial nonuniformities in ion density. Correlation of the probe theory with a zero-order gas dynamic boundary layer theory is shown to lead to theoretical current estimates in fair agreement with the experimentally observed values. Some shock ionization precursor results in air are also presented. Finally, the results of some calibrations on probes that were flown on the RVIP and LORV programs are presented.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1965
Accession Number
AD0464807

Entities

People

  • H. Guthart
  • H. R. Bredfeldt
  • T. Morita
  • W. E. Scharfman

Organizations

  • SRI International

Tags

Communities of Interest

  • Advanced Electronics
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Calibration
  • Charged Particles
  • Collisions
  • Computational Fluid Dynamics
  • Current Density
  • Electron Density
  • Electrons
  • Electrostatic Probes
  • Fluid Dynamics
  • Ion Density
  • Ionization
  • Layers
  • Measurement
  • Shock Tubes
  • Steady State
  • Test Facilities

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Plasma Physics.
  • Theoretical Analysis.