A target qualification station for dynamic compression experiments using the imaging velocity interferometer system...

The velocity interferometer for any reflector (VISAR) diagnostic is a key diagnostic at the National Ignition Facility (NIF) for characterizing how effectively kJ and MJ lasers compress and accelerate planar targets and spherical capsules. The active shock break out diagnostic is also a workhorse at the Omega Laser Facility. Both line-imaging Doppler-shift interferometers require targets with sufficient reflectivity and imaging resolution to collect suitable data. However, off-line target microscope inspection images have not been sufficient due to incompatibility of illumination wavelength, angle, and numerical aperture with those of the NIF and Omega VISAR. To provide a compatible imaging and reflectance measurement capability, we designed and commissioned a VISAR Target Qualification Station (VTQS) at NIF. This system delivers quantitative reflectance maps of target components and completed targets during and at the end of the fabrication process, enabling the shot responsible individual to assess target quality, plan shot operations and VISAR alignment, and support high-quality data collection.