# Vacuum and Gas-Delivery Replay Model Card v1

## Identity

- Experiment: `SA-EQP-VAC-GAS-009`
- Contract version: `2026-08-28-v108`
- Mode: original dimensionless precomputed teaching replay
- Planned rows: 10,368
- Physical replay rows: 5,184
- Evidence pairs: 5,184

## What It Represents

The replay represents a two-inventory teaching system. A chamber inventory receives an admitted source and a decaying wall-source burden. A conductance-limited transfer moves tokens to a foreline inventory. A return term can move foreline tokens back toward the chamber, and a normalized pump-removal term removes tokens from the foreline. Three exact integer ledgers close the chamber, foreline, and combined-system balances at every step.

The normalized proxies expose distinctions among nominal pump capability, conductance, effective pumping, chamber inventory, foreline inventory, pressure-like burden, residence-like burden, source-removal mismatch, distribution stability, and downstream evidence gates.

## What It Does Not Represent

It is not a physical vacuum equation solver, CFD model, DSMC model, Molflow+ run, gas-panel model, mass-flow-controller model, pump curve, conductance calculator, chamber digital twin, contamination model, safety analysis, or facilities design.

It contains no physical pressure, flow, conductance, pump speed, volume, time, temperature, gas identity, gas property, mean free path, Knudsen number, collision rate, leak rate, outgassing rate, residence time, line dimension, valve position, or chamber geometry.

## Flow-Regime Boundary

The labels `continuum_like`, `transition_like`, and `molecular_like` indicate that model selection matters. They do not calculate a regime boundary. Only the molecular-like label may expose a `molecular-model-eligible` teaching gate, and that label still does not prove that a real system is within Molflow+ applicability.

## Measurement Boundary

The pressure and flow fields are normalized proxies. Replacing them requires owned sensor identity, location, gas response, calibration, traceability, range, uncertainty, acquisition timing, and raw trace evidence. A `replacement_slot` row contains no such evidence; it only preserves where evidence would attach.

## Downstream Boundary

Only four categorical fields may be handed to `SA-EQP-PLASMA-CCP-ICP-008`: pressure band, residence band, delivery band, and evidence gate. No physical value, recipe, plasma condition, chemistry, equipment command, or automatic process action may cross the bridge.

## Intended Use

- Teach conductance-limited versus pump-limited reasoning.
- Inspect chamber and foreline inventory closure.
- Compare operator, process-engineer, integration, and yield review gates.
- Build a reproducible browser replay after independent packet validation.
- Identify the exact measured evidence needed to replace each normalized field.

## Prohibited Use

- Pump, line, valve, gas-panel, chamber, exhaust, or abatement sizing.
- Gas recipe, purge, pumpdown, clean, maintenance, or safety instruction.
- Equipment control, qualification, lot disposition, supplier selection, or signoff.
- Claiming physical accuracy, calibration, production fitness, or equivalence to Molflow+, CFD, DSMC, or a named tool.