Spectroscopic modeling for HEDP experiments

Summary form only given. New cutting-edge experiments and advanced spectroscopic diagnostics of HEDP plasmas require state-of-the-art modeling capabilities. One of traditional methods to study the experimental observables is post-processing of hydrodynamics simulations. SPECT3D is an application that uses hydro data and generates synthetic observables such as space-resolved and space-integrated spectra, wide-band and monochromatic images, time-gated images, streak spectra, etc. The hydrodynamic simulations can be performed by the code HELIOS-CR, which is a 1-D radiation-hydrodynamics code with an inline collisional-radiative model, or a variety of other 1-, 2-, and 3-D codes. Alternatively, a set of experimental data can be directly analyzed in an attempt to solve an inverse problem and deduce the conditions of a radiating plasma without relying on hydrodynamics models. Values of common interest (average plasma temperature, density, optical depth), can be readily obtained by comparing experimental data with the results of PrismSPECT spectral calculations. To facilitate detailed comparisons with a complex set of data, data analysis (PEGASYS) and advanced optimization (MULTISIM) applications have been developed. As a demonstration of the modeling capabilities described above, we will present the analysis of a set of experiments performed at Sandia National Laboratories. Opacity experiments at the Z facility provide important data for benchmarking opacity models and atomic data. The availability of these data increases confidence in opacity calculations used for a variety of astrophysical and laboratory plasmas. We will present a series of radiation-hydrodynamics and spectral simulations for the samples that correspond to typical experimental conditions. In particular, we will investigate whether the charge states and level populations in the samples are close to LTE at the time of the measurements. We will also study the possible effects of plasma non-uniformities and deviations of atomic kinetics from steady state. We will discuss recent enhancements to the models, and describe potential applications to a new set of challenging problems. In particular, new models allow for simultaneous computing of spectra and images as observed by multiple detectors. In conjunction with improved data reduction and multi-objective optimization techniques, this provides an opportunity for new studies of ICF capsule implosion experiments and tomographic reconstruction of imploded core spatial structure, fuel-pusher mix, etc.