Accession Number : ADA130254

Title :   Energy Deposition in Epoxy Samples by Absorption of 1.315 Micrometers Radiation,

Corporate Author : MCDONNELL DOUGLAS RESEARCH LABS ST LOUIS MO

Personal Author(s) : Kelley,J D

PDF Url : ADA130254

Report Date : 02 Jul 1981

Pagination or Media Count : 4

Abstract : The purpose of this memo is to desribe a model for absorption of 1.315 micrometers radiation in epoxy composites. The model allows estimation of the percentage of the energy in a radiation pulse which can be absorbed by an epoxy sample before pyrolytic degradation at the effects of energy deposition on a 1-100 microseconds time scale can be treated within the framework of a htermalization model. By this I mean that intra- and intermolecular relaxation processes are taken to be fast enough so that the energy which is absorbed is randomized in times less than a microsecond so that a temperature profile inthe material can be defined. Further, it is assumed that those processes which lead to 'blackening' of the surface are representable by a single rate constant with an Arrhenius temperature dependence; i.e., k = A exp(-delta h/rt). Thus, this model does not consider nonequilibrium processes such as multiphoton absorption, plasma formation at the sruface, etc. In this sense, the model will provide an upper limit to the bulk deposition of energy from a laser pulse.

Descriptors :   *Epoxy compounds, *Sampling, *Absorption spectra, *Radiation, Energy transfer, Deposition, Models, Pulses, Pyrolysis, Thermal analysis, Surfaces, Constants, Rates

Subject Categories : Plastics
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE