Energy Deposition into a Collisional Gas from Optical Lattices Formed in an Optical Cavity (PREPRINT)
Abstract
The Direct Simulation Monte Carlo (DSMC) method was used to investigate the interaction between argon, nitrogen, and methane test gases and ten successive pulsed optical lattices. The one-dimensional lattices were formed by two 100 ps, 393 mJ, 532 nm, laser pulses and were assumed to be far from any electronic resonance. The sequential interaction represents multiple reflections within an optical cavity or the emission of high repetition rate pulsed lasers. The maximum centerline temperature was found as a function of the intervening time between the pulses. An optimum intervening time was found and related to the mean collision time and available unexcited energy modes. The optimum time shifted proportional to the change in gas pressure, thus collision time. During sequential pulses with intervening times near zero, subsequent pulses can act to cool the gas. For pulses with intervening times longer than the optimum, thermal diffusion carries energy away from the centerline, reducing the maximum temperature. The optimal intervening time was found to be 0.7, 1.0 and 0.25 ns for argon, nitrogen, and methane at one atmosphere respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 02, 2008
- Accession Number
- ADA484906
Entities
People
- A. D. Ketsdever
- M. N. Shneider
- S. F. Gimelshein
- T. C. Lilly
Organizations
- Air Force Research Laboratory