الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
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Abstract
The problem of propagation of a CO, laser beam in an absorbing and scattering medium is studied. CO, laser beam is chosen due to the fact that it is highly absorbed by voter droplets whereas tha toner air constituents offer minimum attenuation. We have taken the medium to be composed ‘of a non-uniform distribution of fog droplets of different radii. The problem of evaporation of fog droplets by absorbing infrared radiation, has also Deem considered. The photon transfer equation unhitch describe the variation of the intensity of a beam passing through an absorbing and scattering medium, as a function of both distance x and time t has been treated . This equation has been solved numerically using finite difference technique subject to appropriate boundary conditions, The laser oeam intansity is being attenuated both by absorption ang scattering by fog croplets. Absorption and scattering coefficient of various droplets are calculated by considerations of Mie scattering theory. Also the change in the aroplet size is obtained, The avsorption of laser beam energy lea to evaporation of fog.