Techniques

What the modelled part of P21 is designed to do, as intent. First cut.

A technique is a portable Catalog Method; a Practice is how a facility adapts it. P21's diffraction techniques earn no catalog Method today, so the Methods below render unlinked and are carried pending until a technique enters scope (TECH-1).

High-energy diffraction

P21's P21.2 / EH3 branches use a high-energy monochromatic beam for bulk / engineering diffraction, residual stress, and texture studies on the sample stages, reading area detectors.

Technique	Catalog method	Notes
High-energy diffraction	diffraction	bulk / engineering diffraction on the high-energy branches; reuses the diffraction slug P07 / P08 share, a further consumer (TECH-1)

Total scattering / PDF

P21's P21.1 branch collects total scattering to high momentum transfer for pair-distribution-function analysis.

Technique	Catalog method	Notes
Total scattering / pair-distribution-function	total_scattering	high-Q total scattering on the P21.1 branch; reuses the total_scattering slug i15-1 / XPD / P02 share, a further consumer (TECH-1)

A thin high-energy materials beamline

P21 is a Swedish-collaboration high-energy materials beamline. Its techniques reuse the diffraction and total_scattering slugs already carried across the fleet, so none forces a new Method. The instrument anatomy reuses existing Families (LinearStage, Slit); the sparse registry slice means the model is deliberately thin, with the detectors carried pending.

Not modelled yet

The concrete acquisition recipes (the diffraction / stress-mapping scans, the high-Q PDF collection) are not written yet; they join as the deployment approaches the point where CORA drives P21. Whether the diffraction Methods enter CORA's catalog is an owner-scope decision on Model; see Open questions for the world-facts to confirm first.