Propagation of high power pulses of 10.6 micrometers radiation from a CO2 TEA laser of novel design through clouds produced by a diabatic expansion in the laboratory

This report describes (1) theory, design and performance of a CO2 TEA laser with VUV preionization delivering typically 25J pulses of duration 0.1 microsecond and beam cross section 20 per sq cm; (2) the production of clouds in the laboratory by adiabatic expansion of compressed gas in a 300 1 glass chamber and the measurement of the cloud parameters (liquid water content, drop radius); (3) measurements of attenuation by such clouds of TEA laser pulses of the above type and also measurement of partial cloud clearing by a CW 10.6 micrometer beam (by recording the change in attenuation of a collinear He-Ne beam); and (4) the theory required to understand the interaction betweeen 10.6 micrometers radiation and clouds of droplets.