Abstract
Since 2015 a high-speed (minimum integration time ≈ 2 ns) gated CMOS camera with a “Furi” sensor has been used in the G-LEH diagnostic at the National Ignition Facility to record time-resolved X-ray images of the targets in hundreds of high energy density physics experiments. As these images were analyzed, it became apparent that a more detailed characterization of the camera was needed — specifically, the gate timing profile and responsivity of each pixel — in order to correctly interpret the dynamics in the images. To this end, a pixel-level characterization of the G-LEH Furi camera was recently performed using the COMET laser as a short-pulse ( < 20 ps ) X-ray source. This paper describes the experimental setup and key results for several different timing modes of the camera. The actual widths of the pixel gate profiles were found to be wider than the design goals, with minimum width of ≈ 2 ns. The absolute timing of the pixel gates was measured relative to the output Monitor pulse, reducing the uncertainty in previous timing estimates. Most importantly, pixel-level maps have been produced that show the distribution of responsivity, gate profile width, and gate timing delay across the sensor array, enabling more accurate comparison of the timing and brightness of image features at different locations on the sensor.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Security, LLC, under Contract No. DE-AC52- 07NA27344.
