Creating Movies of Moving Plasma in Space and Frequency
Abstract
University of New Mexico Grant #: FA9451-15-1-0039 “Creating Movies of Moving Plasma in Space and Frequency” Abstract A new method is being developed to create a movie of ultra-intense short laser pulses as they become trapped in self-induced waveguides or “filaments” in the atmosphere. The ultra-slow motion shows the Rayleigh scattering of the pulse of “light bullet” propagating at the speed of light, trailed by the fluorescence emission of the various excited molecules and ions created by the laser pulse. The movie is obtained by stitching multiple (between 1000 and 5000) streak camera exposures taken at different position. Such a movie is invaluable in analyzing the dynamics of the plasma created by the interaction of the intense laser pulse with air molecules. Extreme timing accuracy and repeatability of the 1000 to 5000 shots is required, achieved by launching the laser pulse from vacuum into air through an “aerodynamic window” (a sheet of supersonic air). The biggest challenge is to have an efficient light collection in the extremely short time (ps) that the streak camera resolves. Besides two spatial dimension and time, a third dimension is added by resolving the spectrum of the light collected. This is achieved with prisms or filters. The understanding gained through these measurements will lead to the optimization of a new phenomenon, lasing in air, which can lead to remote sensing of the atmosphere. The movie technique will be extended to visualizing and analyzing the the motion of ions created by the filament in an electric field. It will lead to better understanding and optimization of laser triggered large gap high voltage discharges, ultimately to triggering and guiding lightning for weather research and protection.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 19, 2016
- Source ID
- FA94511510039
Entities
People
- Jean-claude Diels
Organizations
- Air Force Research Laboratory
- United States Air Force
- University of New Mexico