CHIHIRO: inspect the saved shaped-model sweep
Research settingIndependent
CHIHIRO investigates how plasma geometry enters a stability calculation. The work spans shaped ballooning comparisons, equilibrium calculations, external-kink analysis and a Rust implementation that keeps different instability channels explicit.
From the research record
Inspect the work
Original figures, recorded values, and explicit model details. Each exhibit identifies its source and what the comparison means.
The saved shaped-plasma sweep
Scroll horizontally to inspect the full table →
| βN | Signed spectral diagnostic | Worst radial position x | all_stable flag | Suydam violated fraction |
|---|---|---|---|---|
| 0.5 | 0.009823 | 0.0500 | true | 1 |
| 0.8 | -0.009491 | 0.8346 | false | 1 |
| 1 | -0.198168 | 0.8577 | false | 1 |
| 1.2 | -0.398591 | 0.8577 | false | 1 |
| 1.4 | -0.608436 | 0.8808 | false | 1 |
| 1.6 | -0.769188 | 0.8808 | false | 1 |
| 1.8 | -0.897392 | 0.8808 | false | 1 |
| 2 | -1.006743 | 0.8808 | false | 1 |
| 2.2 | -1.093224 | 0.8808 | false | 1 |
| 2.4 | -1.162348 | 0.9038 | false | 1 |
| 2.6 | -1.205199 | 0.9038 | false | 1 |
| 2.8 | -1.241508 | 0.9269 | false | 1 |
| 3 | -1.251243 | 0.9269 | false | 1 |
| 3.2 | -1.279691 | 0.9500 | false | 1 |
| 3.5 | -1.280360 | 0.9500 | false | 1 |
| 4 | -1.142735 | 0.9500 | false | 1 |
| 4.5 | -0.881999 | 0.8808 | false | 1 |
| 5 | -1.163572 | 0.8808 | false | 1 |
The flags are reproduced independently, including disagreement between diagnostics. The source calls the signed value spectral_gap; it is not a universally nonnegative graph-Laplacian gap. This is the shaped model, not a plasma discharge or the separate graph experiment.
Read the technical figure
Saved model calculations with κ = 1.7 and δ = 0.33. Cases are selected, not interpolated into a claimed confinement transition.
- βN 0.5
-
Spectral diagnostic 0.00982254
Most unstable radial position 0.05000
Source type I; Suydam violated 1
- βN 0.8
-
Spectral diagnostic -0.00949071
Most unstable radial position 0.83462
Source type III; Suydam violated 1
- βN 1
-
Spectral diagnostic -0.19816791
Most unstable radial position 0.85769
Source type III; Suydam violated 1
- βN 1.2
-
Spectral diagnostic -0.39859063
Most unstable radial position 0.85769
Source type III; Suydam violated 1
- βN 1.4
-
Spectral diagnostic -0.60843603
Most unstable radial position 0.88077
Source type III; Suydam violated 1
- βN 1.6
-
Spectral diagnostic -0.76918844
Most unstable radial position 0.88077
Source type III; Suydam violated 1
Supporting detail
How shape changes the ballooning boundary
The saved Experiment 12 compares circular, elongated, D-shaped and negative-triangularity configurations. At ten magnetic-shear values per geometry, it records the first pressure-gradient stability boundary and the ratio of shear to that boundary. The resulting curves flatten at different levels over part of the sampled range.
A separate calculation searches for a peak in this ratio and checks the tangent condition at the stationary point. The numerical plateau, the calculus identity and any theorem about uniqueness are different claims. The expanded illustrated study gives the definitions, both views of the boundary, the peak records and the source data.
From equilibrium to a combined diagnostic
Later work uses FreeGS equilibria and studies external-kink stability through an energy-principle calculation. The v5 manuscript reports a wall-free normalized ratio across a 20-profile family. That model result is not an exact identification with a topological constant or a validated confinement law.
The Rust code includes an equilibrium reader and distinct ballooning, external-kink, edge, density-limit, vertical-stability, tearing-mode and resistive-wall channels. A favorable result in one channel does not certify the others. The expanded study also flags a mismatch between the saved equilibrium file’s summary and its raw counts.
Sources, scope, and next question
Deposited preprint, computational implementation and saved model results; experimental predictive accuracy remains to be established.
Compare declared observables against independent stability codes and discharge records, while resolving source-version discrepancies and testing numerical refinement. The earlier graph-spectrum experiment remains linked as a separate mathematical object.