Simulated nonresonant pulsed laser manipulation of a nitrogen flow

Abstract

The continuing advance of laser technology enables a range of broadly applicable, laser-based flow manipulation techniques relevant to a number of aerospace, basic physics, and microtechnology applications. Theories for laser-molecule interactions have been under development since the advent of laser technology. Yet, the theories have not been adequately integrated into kinetic flow solvers. Realizing this integration would greatly enhance the scaling of laser-species interactions beyond the realm of ultra-cold atomic physics. This goal was realized in the present study. A representative numerical investigation of laser-based neutral nonpolar molecular flow manipulations was conducted using non-resonant pulsed laser fields. The numerical tool employed for this study was a specifically modified version of the Direct Simulation Monte Carlo statistical kinetic solver known as SMILE. Flow steering and collimation was simulated for a nitrogen effluence with a stagnation condition of 1 Pa and 300 K emptying into vacuum. The laser pulses were 250 mJ, 5 ns pulses at a wavelength of 532 nm. Flow modification mapped out contours which followed the intensity gradient of the laser field, consistent with the use of the induced dipole gradient force along the field’s radial direction and previously published experiments.