Accession Number:

ADA261402

Title:

Dynamics of Gas-Surface Interactions.

Descriptive Note:

Final technical rept. 1 Jun 1988-31 Oct 1992,

Corporate Author:

CHICAGO UNIV IL JAMES FRANCK INST

Personal Author(s):

Report Date:

1993-01-26

Pagination or Media Count:

48.0

Abstract:

This research initiative deals with the interaction of neutral particle, electron, and optical beams with well-characterized single crystal surfaces. These studies are motivated by a desire to understand and control surface reactions, such as surface oxidation, the technological need to characterize the physical properties of thin films and surfaces, and the desire to understand how energy and momentum are exchanged at the surface of a material when it is subjected to gas-surface collisions, electron-surface collisions, optical illumination, or chemical reaction. Experiments aimed at determining the surface phonon dispersion relations for a variety of clean and adsorbate covered systems play a central role in this program. Such measurements are crucial for elucidating how the force constants at the surface differ from those characteristic of the bulk for a given material, and how adsorption of atomic and molecular species modify the force constants, and hence electron density distributions, at and in the vicinity of the surface. The experimental program utilizes two, now fully operational, scattering laboratories that were constructed with significant DoD funding. One of these is a high resolution energy and momentum neutral particle scattering apparatus which routinely carries out single phonon inelastic as well as diffractive scattering measurements. The other laboratory houses an inelastic electron scattering instrument which also produces momentum-resolved inelastic scattering data. The capabilities of these two facilities complement each other in many important and useful ways.

Subject Categories:

  • Physical Chemistry
  • Crystallography
  • Nuclear Physics and Elementary Particle Physics
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE