ABSTRACT
We have developed the Sample Test Array and Recovery (STAR) platform for the National Ignition Facility (NIF) for studying the thermal and hydrodynamic responses of materials in extreme environments. The STAR platform expands the range of obtainable fluences and quadruples the rate that materials experiments can be conducted at the NIF. Example configurations are demonstrated for fluences spanning 0.56-34 J/cm2 with environmental isolation for post-shot material recovery and inspection and up to 1740 J/cm2 without isolation, with surface heating rates of up to 2 × 1014 K/s. An example experiment involving thermally driven shock and spallation of aluminum alloy 7075 is briefly discussed.
ABSTRACT
We recently developed a one-dimensional imager of neutrons on the Z facility. The instrument is designed for Magnetized Liner Inertial Fusion (MagLIF) experiments, which produce D-D neutrons yields of â¼3 × 1012. X-ray imaging indicates that the MagLIF stagnation region is a 10-mm long, â¼100-µm diameter column. The small radial extents and present yields precluded useful radial resolution, so a one-dimensional imager was developed. The imaging component is a 100-mm thick tungsten slit; a rolled-edge slit limits variations in the acceptance angle along the source. CR39 was chosen as a detector due to its negligible sensitivity to the bright x-ray environment in Z. A layer of high density poly-ethylene is used to enhance the sensitivity of CR39. We present data from fielding the instrument on Z, demonstrating reliable imaging and track densities consistent with diagnosed yields. For yields â¼3 × 1012, we obtain resolutions of â¼500 µm.
