Accession Number:

AD0405814

Title:

A SPECTROSCOPIC STUDY OF RECOMBINATION IN A HELIUM PLASMA

Descriptive Note:

Technical rept.

Corporate Author:

CALIFORNIA UNIV BERKELEY INST OF ENGINEERING RESEARCH

Personal Author(s):

Report Date:

1963-04-05

Pagination or Media Count:

56.0

Abstract:

Recent work on ion-electron recombination has shown that a model involving recombination into highly excited bound levels through electron electron-ion collisions and transitions between the bound levels through electron-atom collisions as well as the usual radiative processes, is in good agreement with experiment. By making absolute intensity measurements of all the lines of helium emitted from the decaying plasma of an arc jet in the visible and near ultraviolet, the number densities of the excited states of helium were calculated. When interpreted by means of the collisional-radiative recombination model, these measurements give values for the collisional deexcitation rate constant of an excited helium atom from level n to n-1. The values of this constant are in reasonable agreement with a recent theory of classical excitation cross sections. A square root dependence of this cross section on the excess energy is indicated, since the values of the collisional de-excitation rate constant appear to be independent of temperature.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE