ABSTRACT
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.
ABSTRACT
We report on what we believe to be the first use of toroidally bent crystals to record two-dimensional, spatially resolved, monochromatic images of laser-produced fusion plasmas combined with a 34-ps fast x-ray framing camera. An array of five toroidal silicon (311) and five toroidal germanium (311) crystals was developed. The imaging properties of the geometries are checked by a ray-tracing program and are compared with experimental results. The total imaging system (crystal and detector) provides an experimentally measured spatial resolution better than 15 mum. Time histories for the hydrogenlike argon emission and the heliumlike argon emission of fusion pellets driven with the GEKKO XII glass laser system are presented.