NTX 0.2.1 Release Notes

NTX 0.2.1 is a validation and documentation hardening release after the first PyPI publication.

Shipping Scope

This release keeps the public package surface compatible with 0.2.0 while refreshing the research artifacts used by the README, docs, benchmark matrix, and manuscript notes. Optional geometry-coupled workflows still require local vmec_jax, booz_xform_jax, and imported workflow checkouts.

Validation Claims

Promoted release claims:

  • monoenergetic validation summary with Legendre convergence and Onsager gates

  • fixed-field Redl/SFINCS interior agreement on the precise-QS QA/QH family

  • fixed-field NTX+NEOPAX reduced-closure total-current stress gate below 1e-1, with no fitted bridge constants

  • W7-X integrated imported-workflow transfer on the rebuilt raw branch

  • prepared derivative-path agreement against direct reverse-mode

Monitored stress diagnostics:

  • species-resolved fixed-field closure parity remains future work

  • VMEC geometry-family D11/D31/D33 convergence breadth scan

  • explicit-relaxed geometry/current derivative stress artifacts

  • implicit-equilibrium derivative diagnostic remains non-shipping

  • CPU/GPU production and fixed-workload strong-scaling performance maps

User-Facing Changes

  • The README fixed-field bootstrap-current figure now shows only overlaid SFINCS, Redl, and NTX+NEOPAX current profiles for QA/QH. Relative-error diagnostics remain in the JSON artifact and physics-gate tests.

  • examples/bootstrap_current_fixed_field_validation.py remains the archive-backed QA/QH example for generating that figure and validating both Redl and NTX+NEOPAX below the 1e-1 interior gate.

  • examples/bootstrap_current_with_neopax.py writes the selected D33 branch to JSON and uses the corrected bootstrap-current assembly without adding the no-momentum and already-corrected momentum branches together.

Release Checks

Verified locally on 2026-04-25 before tagging:

  • python -m ruff check .

  • python -m mypy src/ntx

  • python -m pytest -q: 331 passed, 5 skipped

  • python -m sphinx -b html docs docs/_build/html

  • python -m build

  • python -m twine check dist/*

  • clean-venv wheel smoke test for ntx --help, python -m ntx --help, and importing GridSpec

Tagging

The published tag is v0.2.1.