Evolution of the Hot Spot Density and Temperature on the National Ignition Facility
ORAL
Abstract
The electron density and temperature and their evolution in the hot spot of a Kr-doped, big-foot implosion target were measured for the first time using an absolutely calibrated, streaked, high-resolution x-ray spectrometer named dHIRES [1] on the National Ignition Facility (NIF). The electron density was inferred through Stark-broadened line shapes and the temperature was derived from the relative intensities of dielectronic satellites to the resonance line. The data show that the hot spot density peaks after the x-ray bang time while its temperature peaks before the x-ray bang time. Such trend is compared with a 1-D calculation of the Symcap implosion using a self-similar temperature profile [2], as well as collisional-radiative calculations for line intensities and shapes [3]. [1] L. Gao \textit{et al.}, Rev. Sci. Inst. \textbf{89}, 10F125 (2018). [2] R. Betti \textit{et al.}, Phys. Plasmas \textbf{8}, 5257 (2001). [3] H. A. Scott, JQSRT \textbf{71}, 689--701 (2001).
*This work was performed under the auspices of the U.S. Department of Energy by Princeton Plasma Physics Laboratory under contract DE-AC02-09CH11466 and by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.
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