Kr K-shell x-ray spectroscopy for hot implosion cores

Understanding the spatial structure of implosion cores is important for the development of well-characterized high-energy density science experimental platforms. To this end, we have employed Kr K-shell tracer spectroscopy to extract the temperature spatial distribution in exploding-pusher type implosions at OMEGA that produce core plasmas with electron temperatures of more than 2keV. Two slit imaging spectrometers equipped with Ge crystals were fielded to record spatially resolved Kr K-shell line emission in the photon energy range from 7keV to 20keV. The observations include n=2-1 transitions in Be-, Li- and He-like Kr ions as well as n=3-1 in He-like Kr and associated Li-like satellites. Significant differences are noted between core sizes based on continuum and on line emission. We discuss the interpretation and analysis of the data using detailed atomic and radiation physics models and several methods for the extraction of one-dimensional temperature gradients.



Supported by a DOE/NNSA Center of Excellence grant Contract DE-NA0003868