# 📐  L2 Spec — DESI-MSI Mapping Spec (tissue ambient MSI family)

**ID:** `L2-144-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-144`](/artifact/l1/L1-144)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41554231

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| H | px | 32 – 1024 |
| K | — | 1 – 50 |
| W | px | 32 – 1024 |
| N mz | — | 1000 – 100000 |
| R mass | — | 5000 – 200000 |
| Pixel um | µm | 20 – 500 |
| Spray drift | — | 0.0 – 0.3 |
| Ion suppression | — | 0.0 – 0.8 |
| Pixel stitching error | — | 0.0 – 0.2 |
| Mass calibration error | — | 0.0 – 50 |
| Scan speed variability | — | 0.0 – 0.2 |

## 2. Tolerance (ε)

**Type:** `fn`

```
0.015 + 0.1 * ion_suppression + 0.2 * spray_drift + 0.1 * scan_speed_variability + 5e-4 * mass_calibration_error
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |

## 4. Fingerprint

`e50e6f922e0a36b230ef6a230b6206e9cea2b382b4f098a9036d8d86de11da65`

## 5. On-chain Registration

- **Chain hash:** `0xc6bf6c1b28972be47436b2ab1501b2e3aaf37913d180c591577700ad6ee625c9`
- **Chain tx hash:** `0x6511315b91771fe060a630bc7208bb639d440effe2e4ccec74102117ff9917ec`
- **Chain block:** `41554231`

---

## File Mapping

This bundle consists of: `L2-144-001.md`, `L2-144-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-144-001.md` | Source of truth — edit this | Human or LLM |
| `L2-144-001.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 `L2-144-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._