HELIOS-CR – A 1-D radiation-magnetohydrodynamics code with inline atomic kinetics modeling

Abstract

HELIOS-CR is a user-oriented 1-D radiation-magnetohydrodynamics code to simulate the dynamic evolution of laser-produced plasmas and z-pinch plasmas. It includes an in-line collisionalradiative (CR) model for computing non-LTE atomic level populations at each time step of the hydrodynamics simulation. HELIOS-CR has been designed for ease of use, and is well-suited for experimentalists, as well as graduate and undergraduate student researchers. The energy equations employed include models for laser energy deposition, radiation from external sources, and high-current discharges. Radiative transport can be calculated using either a multi-frequency flux-limited diffusion model, or a multi-frequency, multi-angle short characteristics model. HELIOS-CR supports the use of SESAME equation of state (EOS) tables, PROPACEOS EOS/multi-group opacity data tables, and non-LTE plasma properties computed using the inline CR modeling. Time-, space-, and frequency-dependent results from HELIOS-CR calculations are readily displayed with the HydroPLOT graphics tool. In addition, the results of HELIOS simulations can be post-processed using the SPECT3D Imaging and Spectral Analysis Suite to generate images and spectra that can be directly compared with experimental measurements. The HELIOS-CR package runs on Windows, Linux, and Mac OSX platforms, and includes online documentation. We will discuss the major features of HELIOS-CR, and present example results from simulations.

Thomson Scattering Measurements of Temperature and Density in a Low-Density, Laser-Driven Magnetized Plasma

“…The latter is consistent with an ion density of 3 × 10 13 cm −3 derived from the mass ablated by a heater intensity of 10 11 W/cm 2 over 50 ns into a diamagnetic cavity of size 20 cm using the empirical mass ablation rate in [24]. The derived electron temperatures were also compared to laser-irradiated carbon simulations on HELIOS-CR, a 1-D radiation-magnetohydrodynamic code [25]. The simulations predicted electron temperatures of ∼ 10 eV, comparable to our calculated and spectral values, 3 cm from the target and 0.5 µs after ablation.…”

Inference of ICF implosion core mix using experimental dataand theoretical mix modeling

“…First, a number of 1d HELIOS [22,23] radiation hydrodynamic simulations were performed to study the parameter space based on modifications to the nominal case shown in Fig. 1.…”

“…Next, the parameter space was narrowed down to perform more detailed simulations of the parameters which appeared to be most sensitive to mix. Finally, in-depth modeling of the best pool of candidates for the design was performed with HELIOS-CR [22,23] and was used to make a final determination for the experimental specifications.…”

“…HELIOS-CR, which uses NLTE physics, is generally expected to be more accurate than the baseline HELIOS LTE approach, because the atomic physics and radiation cooling effects of the Ar dopant can be more appropriately dealt with [22,23]. These simulations took approximately 30 hours to run.…”

Hydrodynamic model for expansion and collisional relaxation of x-ray laser-excited multi-component nanoplasma

“…This model provides a general set of transport equations, including even radiative processes, but the source terms are obtained there for a simplified two-fluid case, wherein (i) all atoms are treated as an average neutral fluid and (ii) all electrons together with all singly charged ionic species constitute an average charged fluid. Also, there are commercially available hydrodynamic models such as, e.g., HELIOS, 17 which include many interaction processes and various geometries. However, as these options are built-in into the code, it is difficult to vary them (while testing, e.g., various cross section parametrization), and, in turn, to make a consistent link with the nonequilibrium MD simulations.…”