Abstract of
OPTICAL CHARACTERIZATION OF OF THE LASER-INDUCED SPARK
IN AIR
Phuoc X. Tran, and C.M. White
This present work studies the formation of the laser-induced
spark. Properties such the breakdown probability, spark absorption, spark temperature
and spark evolution were investigated. Spark temperature was measured using the
two-line intensity ratio technique. The absolute intensities emitted from O I
at 748.07 nm and 777.54 nm were used. The beam deflection technique was used for
spark evolution study. It was shown that the laser spark temperature in the order
of 10 5 to 10 6 K could be reached at the end of the laser and that the focal
length of the focusing lens had a strong effect on the breakdown probability,
the spark energy and temperature. The evolution of the laser spark always involved
with the formation and the propagation of the shock wave front, the expansion
of the spark volume, the after-shock perturbation, and the complete shock detachment.
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Diagnostics in Engineering, Volume 5, Part 1 Contents