Te. Mills et al., MEASUREMENT OF EXTINCTION COEFFICIENTS OF LASER-PRODUCED ALUMINUM PLUMES, Journal of thermophysics and heat transfer, 8(2), 1994, pp. 223-228
Radial spectral intensities (0.632 mum) were measured using a He:Ne pr
obe laser scanning an aluminum plume formed by Nd:glass laser irradiat
ion of a target surface. Furthermore, techniques were developed to mea
sure the radial distributions of the extinction coefficients in an axi
symmetric, laser-produced aluminum plume. The techniques developed all
ow for measurements of these distributions as functions of time, wavel
ength, and elevation above the aluminum target. The extinction coeffic
ients determine the ability of the plasma to attenuate incident laser
radiation. The extinction coefficient distribution was determined by s
canning a He:Ne probe laser through the plume and converting line-of-s
ight measurements to a radial distribution. Results indicate that the
aluminum plume is optically thin in the first 80 mus after formation a
nd that the radial extinction coefficient profile has a Gaussian distr
ibution.