# 📐  L2 Spec — Neutron Diffusion — multi-group diffusion approximation Mismatch-Only Spec

**ID:** `L2-355-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-355`](/artifact/l1/L1-355)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554100

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| H | px | 32 – 512 |
| W | px | 32 – 512 |
| Z | — | 32 – 512 |
| Snr db | dB | 0 – 40 |
| N groups | — | 1 – 10 |
| N detectors | — | 8 – 512 |
| D coeff error | — | 0.0 – 0.05 |
| Sigma a error | — | 0.0 – 0.05 |
| Nu sigma f error | — | 0.0 – 0.05 |
| Extrapol dist error | — | 0.0 – 0.1 |

## 2. Tolerance (ε)

**Type:** `fn`

```
1.5 + 50.0*D_coeff_error + 50.0*sigma_a_error + 30.0*nu_sigma_f_error
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |

## 4. Fingerprint

`4ed3911747e41f505fc12bdf818542d5c7795f83507c76ce52d3838ddccacd40`

## 5. On-chain Registration

- **Chain hash:** `0x36a1b045ee79f44a0781d3194e91c169fb8d0b6a35659451202f17d690be97cc`
- **Chain tx hash:** `0xbb33acea8cc26fc9ee44442f4c7efce44cecfd72bc5b6eaa44d42b81ba27f28e`
- **Chain block:** `41554100`

---

## File Mapping

This bundle consists of: `L2-355-001.md`, `L2-355-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-355-001.md` | Source of truth — edit this | Human or LLM |
| `L2-355-001.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 `L2-355-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._