1. Overview & Quick Start
This tool implements the economic Lawson framework to assess fusion power-plant viability.
It computes the economic gain \(Q_{\mathrm{econ}}\) from your input parameters and can
project infeasible designs to nearby viable ones at selected target Q levels.
- Choose or adjust **parameters** with sliders/inputs.
- Optionally enable **Real-time projection (debounced)** for fast previews.
- Set target **Q** values (e.g., 1.0, 1.5), and, if needed, enforce **U ≥** (utilization).
- Click **Full projection to all targets** for accurate nearest viable designs.
- Explore the **heatmap** (2-D slices of Q) with multiple contours.
- **Export** JSON (state), **Import/Apply** JSON to restore, and **Export projections CSV** to share results.
2. Parameters Panel
- Sliders + Value boxes: change any of the ten inputs (Pf/S, τrep, τlife, POE, XS, ηE, (c/Y), (M$/S)S, (M$/S)O/N, i (cost of capital)).
- Scale: toggle **LIN / LOG** slider scaling for positive-domain parameters.
- Lock: if checked, the parameter is held fixed during projection.
- Weight (w): distance weight in the projection metric (set to 0 to ignore a parameter in the distance).
- Live Q & U: the “Current point x” card always shows \(Q_{\mathrm{econ}}(x)\) and utilization \(U(x)\).
3. Projection (Targets Q, Utilization)
The app finds the nearest point y (by a weighted, scaled Euclidean metric) such that
\(Q_{\mathrm{econ}}(y) \ge \text{target}\), with optional utilization constraint \(U(y) \ge U_{\min}\).
- Targets (Q): enter comma-separated values (e.g., 1.0, 1.5, 2.0). The app computes a projection for each target.
- Require U ≥ enables a utilization floor (e.g., 0.80). Projection will satisfy both Q and U if enforced.
- Real-time projection (debounced): fast, lower-iteration preview runs after you stop moving a slider for ~400 ms. Use **Full projection** for high-accuracy solves.
4. Presets
Each preset button loads a full parameter set. Hover a preset to see its values and intent.
- Nominal: Baseline NOAK settings you used in sensitivity analyses.
- ARIES-AT: Approx. advanced tokamak case; higher ηE, moderate Pf/S, relatively low overnight cost density.
- ARC: Approx. compact high-field tokamak; Pf/S≈4, ηE≈0.35, higher overnight cost density.
- SPARC-like: Illustrative research-class surrogate; lower XS, higher costs.
- Optimistic: Aggressive, future-leaning assumptions: higher Pf/S, XS, ηE; faster replacement; favorable POE and capital cost.
- Conservative (non-viable): Cautious stress-test: lower Pf/S & ηE, shorter life, higher costs & capital—typically \(Q_{\mathrm{econ}}<1\).
5. Visualization (Heatmap & Contours)
- Choose **X** and **Y** parameters; set **min/max** ranges and **resolution**.
- Background colors show \(Q_{\mathrm{econ}}\); darker red < 1, lighter → blue > 1.
- Enter multiple **Contour Q levels** (e.g., 1.0, 1.5, 2.0) to overlay isolines with a legend.
- Axes include labels (parameter name + units) and tick marks based on your ranges.
- Use **Download PNG** to save the plot image.
Reset view: Use the Reset view button at the top‑right of the chart (or press the R key). It restores the axis ranges to the defaults for the current axis pair:
Pf/S vs XS → x: 0.5–10, y: 0.5–6; Pf/S vs τrep → x: 0.5–10, y: 0–0.5. It does not change any parameter values or targets.
6. Save / Restore & Export
- Export JSON: saves the complete state (parameters, scales, locks, weights, targets, utilization constraint, viz settings). Also shown in the JSON box for copy/paste.
- Import JSON / Apply JSON: restore a saved state from file or by pasting into the JSON box.
- Export projections CSV: writes target Q projections (one row per target), including whether current x already satisfies each target.
- Download PNG: saves the current heatmap plot.
7. Tips, Notes & FAQ
- Viability: \(Q_{\mathrm{econ}} \ge 1\) is necessary; many commercial cases target \(Q \ge 1.5\)–2.0 for margin.
- Locks & Weights: Lock fixes parameters during projection; weights shape the distance metric—emphasize the variables you can realistically change.
- Performance: If previews feel slow, reduce target count or temporarily disable real-time projection.
- Keyboard: Press ? to open this guide; Esc to close.
- Data privacy: Everything runs locally in your browser; files you export are saved on your machine.
