# 📐 L2 Spec — Cryogenic Storage Boiloff — MLI heat-leak estimation Mismatch-Only Spec
**ID:** `L2-206-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-206`](/artifact/l1/L1-206)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554039
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| T c k | — | 4 – 250 |
| T h k | — | 77 – 500 |
| Snr db | dB | 0 – 40 |
| N layers | — | 1 – 100 |
| N samples | — | 10 – 10000 |
| Layer spacing error | — | 0.0 – 0.3 |
| Vacuum pressure error | — | 0.0 – 0.001 |
| Layer emissivity error | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
18.0 + 0.3*SNR_dB - 15.0*layer_emissivity_error - 5000.0*vacuum_pressure_error - 8.0*layer_spacing_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`96d836d78b5647be4b5705cec4f54ce6f4b2c80638781ac324d0bbf4bdd5c1f1`
## 5. On-chain Registration
- **Chain hash:** `0xc0eda79f933c0aac237768cd729e98965f1fbc03f4e9b2f625ac27412cf325de`
- **Chain tx hash:** `0xc20df66902f44a3b50726680199577b5449df8cbd0cad25b588b2374797f6aa4`
- **Chain block:** `41554039`
---
## File Mapping
This bundle consists of: `L2-206-001.md`, `L2-206-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-206-001.md` | Source of truth — edit this | Human or LLM |
| `L2-206-001.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 `L2-206-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._