Accession Number:

ADA199498

Title:

The Relationship between Ultraviolet Photon Stimulated Desorption Mechanisms and Fundamental Materials Properties

Descriptive Note:

Final rept.

Corporate Author:

VANDERBILT UNIV NASHVILLE TN

Report Date:

1986-01-01

Pagination or Media Count:

98.0

Abstract:

The statement of work involved free-electron-laser-related activities using synchrotron uv sources and frequency up-converted laser light 1 to measure the energy dependence of photon-induced processes of desorption to vary temperatures of the irradiated samples over a wide range to ascertain the effects of defect mobilities on desorption processes to use pump-probe techniques to study the time dependence of the energy localization and desorption processes and to perform kinematically-complete experiments in which all the neutral desorbed species and appropriate level spectroscopy occurs to allow unambiguous identification of the mechanisms. The motivation for the work arose from the need for a clearer understanding of fundamental processes of materials modification and damage in ultraviolet optical materials, particularly with reference to the hoped-for developments in short wavelength free-electron lasers FELs. The major objective of the proposal was the elucidation of mechanisms through which bombardment by energetic ultraviolet photon beams over a wide range of energies leads to surface modification, erosion and macroscopic damage. The program emphasis was to be on threshold effects, time structure, interaction mechanisms both thermal and electronic, and the influence of differing bonding mechanisms on desorption induced in both layers and substrates.

Subject Categories:

  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE