TIME RESOLVED SIDE SCATTER DIAGNOSTICS AT NOVA

Side scattering of radiation during the interaction of a laser beam with the long scale length plasma in a hohlraum is a difficult problem that is relevant to the viability of inertial confinement fusion. It is important to measure the absolute amount of laser side scatter as well as the angular distribution of that scatter. The oblique scatter array (OSA) diagnostics have been implemented on NOVA to measure these quantities. We have used a fiber-optically coupled streak camera to measure the temporally and angularly resolved side scatter radiation at 351 nm at nine different angles. Filtered PIN diodes were positioned at 31 various angles in the E-field plane and B-field plane of the incident probe beam to sample and measure the scattered radiation at the 351 nm wavelength of the probe. The diode data was used to calibrate the Brillouin power received by the nine strategically located fiber optic channels. This presentation describes the OSA and associated diagnostics.