Full-Aperture Backscatter Measurements on the National Ignition Facility

The National Ignition Facility's Full-Aperture Backscatter Station (FABS) is described. The FABS uses five independent diagnostics on each of the four laser beams in the initial NIF quad to measure the energy, power, spectrum, and near-field amplitude modulations of the stimulated Brillouin and stimulated Raman backscattered light. In initial tests CO{sub 2} and C{sub 5}H{sub 12} gas-filled targets were used to create various backscatter conditions. Results are presented for tests in which 16 kJ on target produced between 0.3 kJ and 2.5 kJ of backscattered light.