ABSTRACT
The off-axis forward-scattered radiation from a low energy He-Ne laser, scattered by high density hydrosols, is studied experimentally and theoretically. The validity range of theoretical calculations is determined using four measurements with two optical depths and two detector fields of view. For narrow field of view detectors, experimental and theoretical agreement is good close to the beam axis and decreases with transverse distance; agreement is good at greater distances from the beam axis using an open detector. The small-angle approximation adequately describes multiple scattering close to the beam; calculations are significantly improved by combining the small-angle approximation with diffusion theory.
ABSTRACT
A new contact microradiographic system for analyzing laser fusion targets with 2-D modeling and image analysis techniques is described. This system, which uses a monochromatic x-ray source and Kodak highresolution plate emulsion, is sensitive to spherical wall thickness variations (eccentricities) as small as +/-200 A in hollow shells with a mean wall thickness of 1 microm. Measurements of wall thickness and of local and spherical wall thickness variations by radiographic techniques, using 2-D video, digital image analysis, and optical interferometry, are compared.
