Accession Number:

AD0903665

Title:

PROBE - A Digital Computer Program for Computing Langmuir Probe Current-Voltage Characteristics.

Descriptive Note:

Final rept. Jan 71-Apr 72,

Corporate Author:

GENERAL ELECTRIC CO PLEASANTON CA NUCLEAR THERMIONIC POWER OPERATION

Personal Author(s):

Report Date:

1972-08-01

Pagination or Media Count:

71.0

Abstract:

This report documents PROBE - A digital computer program for computing Langmuir probe current-voltage characteristics. PROBE computes current-voltage characteristics and potential, electric field, and charged particle density profiles for a spherical Langmuir probe in a collision dominated slightly ionized gas. The operating point for a Langmuir probe is probe radius, plasma charged particle density, plasma charged particle temperatures and collision frequencies between the charged particles and neutral particles. The computation is performed by numerically integrating a set of plasma transport differential equations which conserve mass momentum and energy in one dimensional spherical geometry. Computed characteristics have been obtained for a broad range of plasma conditions including collisionless and collision dominated extremes. The computed probe characteristics have been compared with previous results and the theoretical approach is concluded to be sound. Current-voltage characteristics computed with PROBE have the correct theoretical dependence in the collisional limit yielding the Maxwell or temperature line for highly retarding potentials and exhibiting diffusion limited saturation for highly accelerating potentials and in the collisionless limit yielding the Maxwell or temperature line for retarding potentials and the collisionless thick sheath limit for accelerating potentials. Author

Subject Categories:

  • Computer Programming and Software
  • Computer Hardware
  • Test Facilities, Equipment and Methods
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE