Accession Number:

AD0296210

Title:

PERTURBATION OF A PLASMA BY A PROBE

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS

Personal Author(s):

Report Date:

1962-12-26

Pagination or Media Count:

50.0

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.

Subject Categories:

  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE