Results From the New NIF Gated LEH imager*

A novel ns-gated Laser Entrance Hole (G-LEH) diagnostic has been successfully implemented at the National Ignition Facility (NIF). ~This diagnostic has successfully acquired images from various experimental campaigns, providing critical information for inertial confinement fusion experiments. The G-LEH diagnostic which takes time-resolved gated images along a single line-of-sight, incorporates a high-speed multi-frame CMOS x-ray imager developed by Sandia National Laboratories into the existing Static X-ray Imager diagnostic at NIF. It is capable of capturing two laser-entrance-hole images per shot on its 1024x448 pixel photo-detector array, with integration times as short as 2 ns per frame. The results that will be presented include the size of the laser entrance hole vs. time, the growth of the laser-heated gold plasma bubble, the change in brightness of inner beam spots due to time-varying cross beam energy transfer, and plasma instability growth near the hohlraum wall.