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SCPN Fusion Core v2.1.0 — Disruption FPR Fix, Self-Consistent GS-Transport, MHD Stability Expansion

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@anulum anulum released this 17 Feb 18:47
· 1358 commits to main since this release
v2.1.0
f4c4d23

v2.1.0 — Disruption FPR Fix, Self-Consistent GS-Transport, MHD Stability Expansion

Physics hardening release closing the critical gaps identified in v2.0.0.

Highlights

  • Disruption predictor recalibrated: FPR reduced from 90% to 0%, recall maintained at 100% on 16-shot reference dataset
  • GS-Transport self-consistency loop: run_self_consistent() outer iteration couples transport with equilibrium re-solve until psi convergence
  • MHD stability expanded (2 -> 5 criteria): Added Kruskal-Shafranov, Troyon beta limit, NTM seeding
  • beta_N estimator calibrated: ITER error -96% -> -2.8%; SPARC -42% -> +3.0%
  • FreeGS blind benchmark: Solov'ev analytic fallback for 3 test cases

Disruption Predictor — Before/After

Metric v2.0.0 v2.1.0 Change
False Positive Rate 90% 0% Fixed
Recall >= 60% 100% Improved
Risk threshold 0.65 0.50 Pareto-optimal

Feature weight recalibration: instability indicators (std, slope) prioritised over raw amplitude (max_val). Safe high-power shots no longer trigger false alarms.

  • thermal_term: max_val 0.55 -> 0.03, std 0.35 -> 0.55, slope 0.25 -> 0.50
  • state_term: mean 0.15 -> 0.02, last 0.20 -> 0.02
  • New threshold sweep tool: tools/sweep_disruption_threshold.py with ROC curve

GS-Transport Self-Consistency

Transport evolve -> map_profiles_to_2d() -> solve_equilibrium() -> check ||psi_new - psi_old||/||psi_old||
                                                                         |
                                                          converged? ----+---- iterate
  • TransportSolver.run_self_consistent() with configurable tolerance
  • Backward-compatible: run_to_steady_state(self_consistent=True) delegates to new loop

MHD Stability (2 -> 5 Criteria)

Criterion Equation Source
Mercier D_I > 0 (interchange) Existing
First-stability ballooning s-alpha diagram Existing
Kruskal-Shafranov q_edge > 1 New
Troyon beta limit beta_N < g (no-wall g=2.8, ideal-wall g=3.5) New
NTM seeding Simplified Modified Rutherford, bootstrap-drive marginal island width New

run_full_stability_check() returns StabilitySummary dataclass. All types exported from scpn_fusion.core.

beta_N Calibration

Machine v2.0.0 Error v2.1.0 Error Improvement
ITER -96% -2.8% 33x better
SPARC -42% +3.0% 14x better
RMSE 1.26 0.042 30x better

Profile peaking correction factor: 1.446 (geometric mean of ITER/SPARC calibration). CI gate tightened from 2.00 to 0.10.

FreeGS Blind Benchmark

Test Case R0 (m) Type PSI NRMSE Threshold
ITER-like 6.2 Large aspect ratio < 10%
SPARC-like 1.85 Compact high-field < 10%
Spherical tokamak 0.85 Low aspect ratio < 10%

freegs>=0.6 added to [benchmark] optional dependencies. Solov'ev analytic fallback when freegs not installed.

Test Suite

Test File Tests New
test_disruption_threshold_sweep.py 7 Yes
test_gs_transport_coupling.py 14 Yes
test_mhd_stability.py 25 15 new
test_freegs_benchmark.py 27 (+2 skip) Yes
Total 1225 passing 57 skipped

Files Changed

  • src/scpn_fusion/core/stability_mhd.py — 3 new stability criteria
  • src/scpn_fusion/core/integrated_transport_solver.py — run_self_consistent()
  • src/scpn_fusion/control/halo_re_physics.py — feature weight recalibration
  • src/scpn_fusion/core/fusion_ignition_sim.py — beta_N peaking correction
  • validation/benchmark_vs_freegs.py — Solov'ev benchmark
  • tools/sweep_disruption_threshold.py — ROC curve generator
  • RESULTS.md — calibrated metrics, resolved-status flags

Full changelog: https://github.com/anulum/scpn-fusion-core/blob/main/CHANGELOG.md

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