Accession Number:

AD0646320

Title:

ON THE EXPERIMENTAL DETERMINATION OF MICROSTATE DISTRIBUTIONS ASSOCIATED WITH GAS-SURFACE SCATTERING,

Descriptive Note:

Corporate Author:

BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH FLIGHT SCIENCES LAB

Personal Author(s):

Report Date:

1966-10-01

Pagination or Media Count:

21.0

Abstract:

A method for determining velocity distributions in surface-scattered molecular beams is described. Time-of-flight effects in the modulated beams provide the means for extracting the velocity distributions from measured waveforms in the number density. A generalization of the method, applicable to the investigation of velocity-residence time distributions, is proposed for interactions in which the surface residence times are of the order of the molecular flight times. A system of broad-band lock-in beam detection, useful for signal-to-noise enhancement, is also described. For demonstrative purposes, the method is used to examine collisional effects in direct beams generated with an array of capillary tubes. Evidence is found that the observed collisional reductions in beam intensity are associated with both internal scattering inside the capillary tubes and self-collision in the highly directional post-array density field. Author

Subject Categories:

  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE