# 📐 L2 Spec — Proton Therapy (proton-beam radiation dose imaging) Mismatch-Only Spec
**ID:** `L2-051-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-051`](/artifact/l1/L1-051)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41553375
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 |
| W | px | 128 |
| Z | — | 32 – 512 |
| Snr db | dB | 10.0 – 40.0 |
| N beams | — | 1 – 16 |
| Organ motion | — | 0.0 – 0.3 |
| Proton energy mev | — | 70 – 250 |
| Range uncertainty | — | 0.0 – 0.05 |
| Tissue heterogeneity | — | 0.0 – 0.3 |
| Ct hu calibration error | — | 0.0 – 0.1 |
## 2. Tolerance (ε)
**Type:** `fn`
```
19.0 + 0.3 * SNR_dB - 100.0 * range_uncertainty - 8.0 * organ_motion - 10.0 * tissue_heterogeneity
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`c2e64d5d06f9b9a3d2d995e4d24e09e5a27e163c54805af7cbc51bc6bf512bf1`
## 5. On-chain Registration
- **Chain hash:** `0x597ee27b1e678336b59ea2571ee6941d0a8cf78d6677124b5fb66d37d78a2c32`
- **Chain tx hash:** `0x0eb22f3abf5a428ede23c3cd9cf249306b845e48c294363ab82c42154f35af4f`
- **Chain block:** `41553375`
---
## File Mapping
This bundle consists of: `L2-051-001.md`, `L2-051-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-051-001.md` | Source of truth — edit this | Human or LLM |
| `L2-051-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-051-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._