Accession Number : AD0636533

Title :   THEORY OF ELECTRON COLLISION EXPERIMENTS AT INTERMEDIATE AND HIGH GAS DENSITIES.

Descriptive Note : Technical rept.

Corporate Author : WESTINGHOUSE RESEARCH LABS PITTSBURGH PA

Personal Author(s) : Chantry, P. J. ; Phelps,A. V. ; Schulz,G. J.

Report Date : 29 APR 1966

Pagination or Media Count : 79

Abstract : By means of a two stream approximation an analytical solution is obtained to the equation of transfer governing the steady state concentration of monoenergetic electrons within a slab of gas bounded by two infinite planes, one of which emits a constant current density normal to its surface. The theory places no restriction on the gas pressure and includes the effects of inelastic collisions and partial reflection of scattered electrons at one or both boundaries. The results are applied to electron beam experiments at intermediate and high pressures where the mean free path of electrons is comparable to or less than the length of the collision chamber. Analytical expressions are obtained for the electron current transmitted through the gas and for the normalized ion currents to be expected in the case of total ion collection and in the case of sampling through a slit. The effect of elastic and inelastic collisions may be represented by an 'equivalent length factor' which modifies the equations normally applicable under low pressure conditions. The results of the present theory are compared with previous theories with particular reference to their use in interpreting experiments of the Maier-Leibnitz type, designed to measure absolute values of inelastic collision cross sections. (Author)

Descriptors :   (*ELECTRON BEAMS, SCATTERING), ELASTIC SCATTERING, INELASTIC SCATTERING, DIFFUSION, HIGH PRESSURE, MASS SPECTRA, THEORY, PROBABILITY

Subject Categories : Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE