v0.2.0

Upcoming API Changes: The next major release of TORAX will include significant API updates, including changes to the configuration structure, a transition to a hierarchical xarray DataTree output format, and variable renaming for improved consistency. This release (v0.2.0) provides a stable version for users who wish to continue development with the current API.

TORAX improvements since v0.1.0 (highlights)

• Physics Model Improvements:

  • Added Gaussian smoothing option for transport models.
  • Implemented support for spatially varying Zeff profiles.
  • Integrated a neural network wrapper for the Toric ICRH ML-surrogate model (using Flax).
  • Added Bremsstrahlung radiation sink.
  • Added BohmGyroBohm transport model.
  • Implemented ECCD with Lin-Liu current drive formula.

• Geometry Input Extensions:

  • Added support for MEQ (FBT) geometry input.
  • Enabled EQDSK geometry input with flux-surface averaging.
  • Implemented support for time-dependent geometries:
    • Support for multiple geometry files or bundled FBT files (via liuqe meqlpack).
    • Calculation of time-dependent phibdot term in governing equations.

• Configuration and Sim object construction improvements

  • Enabled flexible input of prescribed data using Python primitives, NumPy, and xarray.
  • Expanded support for prescribing time-dependent profiles, including core profiles and sources.
  • Significantly improved simulation setup speed by pre-interpolating input arrays and preparing time interpolation providers.
  • Enhanced the methodology for Ip scaling, supporting both parameter-based and geometry file-based definitions.

• Developer Quality of Life:

  • Redesigned source management for improved modularity and easier integration of new sources.
  • Restructured transport_models to increase modularity, simplify new model integration, and reduce redundant code.
  • Enhanced type safety with array typing and typeguard annotations.
  • Implemented helper scripts for managing and updating simulation integration tests.
  • Divided SimulationStepFn into distinct phases, enabling external modification of dynamic runtime parameters at each simulation step.

• Bugfixes:

  • Corrected QLKNN magnetic shear calculation.
  • Fixed Coulomb constant calculation.
  • Resolved issues with impurity density and boundary condition updates.
  • Fixed a bug in external current profile updates.

• Extended Outputs:

  • Added stepper numeric outputs, including error codes and iteration counts.
  • Expanded post-processed outputs, such as integrated currents, sources, fusion gain, and pressure.
  • Added output of the plasma current profile calculated from the poloidal flux.

• Documentation:

  • Significantly expanded documentation, covering physics models, solver details, code structure, and developer guides.
  • Improved docstrings and comments for enhanced code readability.

• Miscellaneous:

  • Enabled nightly and pull request-triggered unit tests in CI.
  • Added a JAX profiler (optional, flag-activated) for performance analysis.
  • Implemented a configurable, data-driven plotting library.
  • Implemented various performance optimizations, including solver improvements and JIT compilation of simulation setup.
  • Enabled JAX persistent cache for faster execution.
  • Added support for restarting simulations from arbitrary time points using existing TORAX output files.
  • Modified governing equations for consistency with normalized toroidal flux as the radial coordinate.
  • Improved various equation calculations, including q-profile and current calculations.

v0.1.0

Initial release of TORAX.