Accession Number:

AD1004766

Title:

Merging Hyperspectural Imagery and Multi Scale Modeling for Laser Lethality

Descriptive Note:

Technical Report,15 Sep 2010,14 Nov 2015

Corporate Author:

University Of Virginia Charlottesville United States

Report Date:

2016-02-24

Pagination or Media Count:

19.0

Abstract:

The overall goal of the project was to develop advanced computational models for analysis of the effect of external flow on material removal in laser ablation of metals in oxidizing environment and under the influence of air flow. The models are applied for investigation of the combined effect of the laser energy deposition, chemical reactions, and air flow on the material removal rate and the nature of laser damagemodification of irradiated targets. The results of this project include the elucidation of 1 the relative contributions of the recoil vapor pressure and Marangoni effects on the melt dynamics and melt through time in the laser melting of free-standing aluminum films, 2 the effect of the external gas pressure on the flow structures and the mechanisms of the alumina and oxygen transport to the target surface, 3 the distinct characteristics of short pulse laser interactions with a metal target under conditions of spatial confinement by a solid transparent overlayer, 4 the conditions for the formation of nanocrystalline surface layer, sub-surface voids, and frozen surface nanospikes in surface nanostructuring by short laser pulses, 5 the effect of sample porosity on laser-induced carbon pyrolysis and oxidation.

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE