Accession Number:

ADA261124

Title:

Photoionization in Collision Complexes

Descriptive Note:

Final rept. May 1989-Oct 1990

Corporate Author:

NEW MEXICO ENGINEERING RESEARCH INST ALBUQUERQUE

Report Date:

1991-12-01

Pagination or Media Count:

78.0

Abstract:

The overall objective of this effort was to determine the potential roles of van der Waals complexes of dioxygen, hydrocarbon fuel, and halon molecules in combustion and extinguishment. This study provides insights into the reactions between the fire extinguishant CF3Br and the dominant flame free radicals H, O, and OH. Molecular complexes of halondioxygen, halonhydrocarbon, and hydrocarbondioxygen were generated by expansion of gas mixtures through a supersonic nozzle. These complexes then underwent dissociative photoionization followed by mass spectrometric analysis. Photoion yield curves were analyzed to characterize fragmentation processes and energy states. Thermodynamic properties of the clusters and fragments were measured. No evidence of interaction Of CF3Br with H atoms was found. Studies of frozen collision complexes offer a powerful method for elucidating the initial steps of reaction chemistry. Small heteroclusters were prepared, relative number densities of neutrals were determined, kinetic energy distributions of fragment ions were measured, and the first reported analysis of clusters in a ternary molecular beam was carried out. The results of these experiments have many potentially significant implications for development of alternative fire suppression agents.... Complexes, Clusters, Halon, Fuel, Oxygen, Radical, Mechanism, Extinguishment.

Subject Categories:

  • Organic Chemistry
  • Nuclear Physics and Elementary Particle Physics
  • Thermodynamics
  • Fuels

Distribution Statement:

APPROVED FOR PUBLIC RELEASE