AVS 62nd International Symposium & Exhibition
    Thin Film Wednesday Sessions
       Session TF+AS+EM+EN+MN-WeA

Paper TF+AS+EM+EN+MN-WeA3
Reactive Foil Ignition by Laser Irradiation: Experimental and Modeling Results

Wednesday, October 21, 2015, 3:00 pm, Room 111

Session: CV Infiltration Methods and Energetic and Thermal Properties of Thin Films
Presenter: Ryan Murphy, Sandia National Laboratories
Authors: R.D. Murphy, Sandia National Laboratories
C.D. Yarrington, Sandia National Laboratories
R.V. Reeves, Lawrence Livermore National Laboratory
D.P. Adams, Sandia National Laboratories
Correspondent: Click to Email
It has been shown that forced mixing of reactive layers (foils) leads to an exothermic release of energy after initiation by pulsed laser irradiation. In order to understand the ignition of foils initiated by laser irradiation, we study the interaction of laser pulses with Al/Pt multilayer reactive foils prepared by sputter deposition. It will be shown that the single-pulse ignition threshold and dynamics are dependent on the length of the laser pulse as the pulse length is varied from 150 fs to 100 ms. The dependence of the ignition threshold on pulse length is a combination of laser-material interactions such as the size of the heat affected zone and the onset of ablation for ultrafast irradiation. Simulations of single-pulse laser heating were performed with Aria, the thermal package of the SIERRA finite element computational framework. Three-dimensional geometries were subjected to laser flux boundary conditions equal to those measured from the experimental conditions. Modeling and experimental results are correlated to show the effects of the heat affected zone size and shape on ignition thresholds and onset times.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94AL85000.