Helios v11.0: High-Energy-Density Physics Simulation Software

Helios v10.0 is a major release of Prism Computational Sciences’ simulation platform for high-energy-density (HED) physics experiments, supporting 1D planar, cylindrical, and spherical geometries . This version introduces significant physics updates, improved memory handling for large data tables, and enhanced simulation capabilities for radiation hydrodynamics .

Key New Features in Version 11.0

Physics & Radiation Modeling Enhancements

  • Advanced Radiation Sink Modeling: The user can now specify radiation energy loss in terms of a leakage area A(t), providing more flexible and realistic boundary condition control .

  • Improved Collisional-Radiative (CR) Physics: Several updates to the CR models include photon energy grid refinement for photo-absorption and spectral modeling, a continuum lowering model that preserves transitions near the ionization threshold, and improved bound-bound emissivities with additional line wings .

  • Time-Step Optimization: Automatic adjustment of time steps for the non-local time-dependent population solver to enhance stability and accuracy .

Expanded Data & Memory Support

  • Large SESAME Table Support: Added support for large SESAME tables with up to 1 million words, enabling the use of more detailed material models. Also includes initial support for the SESAME ASCII2 format .

Bug Fixes & Performance

  • Simulation Corrections: Fixed energy conservation issues for simulations using the radiation sink . Resolved inconsistencies in determining masses and zone widths at material interfaces during automatic zoning .

  • Thread Safety: Simulations using the radiation sink are now thread-safe .

  • HydroPLOT Fixes: Corrected an issue where only inner boundary values were plotted for incident flux or radiation drive temperature, regardless of which boundary was selected .

Core Capabilities

Helios provides a robust framework for modeling high-energy-density physics experiments with the following features :

  • Multi-Dimensional Support: 1D planar, cylindrical, and spherical geometries with Lagrangian hydrodynamics (grid moves with fluid) .

  • Energy Models: One-temperature (Tion = Telec) or two-temperature (separate Tion and Telec) plasma energy equations .

  • Radiation Transport: Offers multiple models, including Flux-limited radiation diffusion and a Multi-angle short characteristics method for planar geometry .

  • Energy Deposition: Models for laser deposition, MHD effects (cylindrical geometry), and external radiation sources .

  • Material Models: Supports SESAME equation of state (EOS), thermal conductivity, and electrical resistivity data, as well as Prism’s own PROPACEOS data .

  • Diagnostic & Visualization Tools: Includes the HydroPLOT application for visualizing results and interfaces with SPECT3D for generating synthetic spectra and images .