Abstract
An experimental investigation has been conducted to study pulsed laser energy propagation over long distance through the atmosphere. Typical gain switched pulse of the CO2 cold cathode electron gun laser (160 J, 2.5 /AS) shows an initial high-power spike (5.6 x 108 W, 50 ns FWHM) followed by a high-energy tail (130 J). The laser beam is focused by means of of a 5 X telescope outside the laboratory. Spatial and temporal distributions of intensity and energy density are measured in the breakdown area by burning of thermosensiti ve paper (envelope of the focused laser beam) and by use of calibrated Kalvar film (focal spot). Experimental determination of the air breakdown average threshold (l-2x!08 W/cm2, 3-5 J/cm2) leads to the conclusion that such a phenomenon is initiated on the spike of the pulse by > 4-^m-diam aerosol particles. A particle optical counter is used for in situ measurements of aerosol distribution (axially scattering spectrometer probe, calibrated in the 0.5 ftm <c?<45 iim range), to determine the number in the focal volume.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
