Accession Number : AD0800686

Title :   ANALYSIS OF INTENSITY AND SPEED DISTRIBUTION OF A MOLECULAR BEAM FROM A NOZZLE SOURCE.

Descriptive Note : Technical rept.

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE

Personal Author(s) : Hagena, Otto F. ; Morton, Harold S., Jr

Report Date : OCT 1966

Pagination or Media Count : 25

Abstract : The present theoretical models to describe intensity and speed distribution in molecular beams from nozzle sources are reviewed and their respective shortcomings are discussed with close reference to the physical processes responsible for the beam formation. These processes had not been included in the theory with the result of overly optimistic predictions of intensity and thermal spread of these nozzle beams. It is shown that inclusion of the flow divergence in front of the first aperture called skimmer and the temperature anisotropy predicted by kinetic theory results in appreciably lower values of intensity and modifies the velocity distribution. Even with these corrections the theories can be applied only if the skimmer interaction is avoided by keeping the skimmer Knudsen number above one and furthermore, if the sourch Knudsen number is not so small as to result in a partial condensation of the beam gas. (Author)

Descriptors :   (*MOLECULAR BEAMS, MATHEMATICAL MODELS), INTENSITY, VELOCITY, DISTRIBUTION, NOZZLES, THEORY, TEMPERATURE, FLUID MECHANICS.

Subject Categories : Particle Accelerators

Distribution Statement : APPROVED FOR PUBLIC RELEASE