IMAGING BACKSCATTERED AND NEAR TO BACKSCATTERED LIGHT IN IGNITION SCALE PLASMAS (INVITED)

Diagnostics have been developed and fielded at the Nova laser facility that, for the first time, image nearly all the Light scattered within 20 degrees of the laser axis, including the light collected by the la ser focusing lens as well as that just outside the lens. Absolute cali bration of optical components exposed to the target debris have been a chieved by a combination of routine in situ calibration and maintenanc e. Measurements from plasmas relevant to ignition experiments indicate that scattering is peaked in the direction of backscatter with signif icant energy scattered both into the lens and just outside the lens. T he scattering outside the lens is found to be dominant when the f numb er is large (f/8). (C) 1997 American Institute of Physics.