PERTURBATION OF A PLASMA BY A PROBE

Abstract

The perturbation of the plasma by a probe is analyzed as a problem in ambipolar diffusion, subject to the assumptions that the mean-free path of plasma particles is: (1) comparable to or smaller than probe dimensions, and (2) much greater than the thickness of any sheaths that may be present. Sheaths must therefore be assumed to be thin in comparison with probe dimensions. Analyses are carried through for spherical probes and for plane probes oriented normal to a magnetic field. The results can be expressed in terms of a parameter Q which is approximately equal at zero sheath potential to the sum of the ratios of probe size to electron mean-free path and probe size to ion mean- free path. Since Q also depends on sheath potential, the current-voltage characteristics are distorted.

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Document Details

Document Type
Technical Report
Publication Date
Dec 26, 1962
Accession Number
AD0296210

Entities

People

  • John F. Waymouth

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boltzmann Equation
  • Current Density
  • Diffusion
  • Diffusion Theory
  • Electric Fields
  • Electron Density
  • Electron Energy
  • Electrons
  • Energy
  • Equations
  • Government Procurement
  • Governments
  • Ion Density
  • Magnetic Fields
  • Mean Free Path
  • Measurement
  • United States Government

Readers

  • Fluid Dynamics.
  • Plasma Physics.

Technology Areas

  • Microelectronics