Spectroscopic determination of dynamic plasma gradients in implosion cores

The time-dependent gradient structure of a laser-compressed, high-energy-density plasma has been determined using a method based on the simultaneous analysis of time-resolved x-ray monochromatic images and x-ray line spectra from Ar-doped D2 implosion cores. The analysis self-consistently determines the temperature and density gradients that yield the best fits to the spatial-emissivity profiles and spectral line shapes. This measurement is important for understanding the spectra formation and plasma dynamics associated with the implosion process. In addition, since the results are independent of hydrodynamic simulations, they are also important for comparison with fluid-dynamic models.