Techniques¶
What the modelled part of P04 is designed to do, as intent. First cut.
A technique is a portable Catalog Method; a Practice is how a facility adapts it. P04 runs soft X-ray spectroscopy, which earns no catalog Method today, so the Methods below render unlinked and are carried pending until a technique enters scope (TECH-1).
Soft X-ray absorption spectroscopy¶
P04 sets the photon energy (250-3000 eV) by coupling the variable-polarization undulator and the plane-grating monochromator, then scans it across an absorption edge while reading the sample drain current on the electrometer (total electron yield).
| Technique | Catalog method | Notes |
|---|---|---|
| Soft X-ray absorption (XAS / NEXAFS) | xas_spectroscopy |
the undulator + PGM photon-energy scan reading the Keithley electrometer; reuses the xas_spectroscopy slug four sites share, a further consumer (TECH-1) |
Photoemission¶
P04's variable polarization and soft X-ray energy range suit photoemission on the EXP endstations (the analyzer is an endstation instrument not exposed as a motor in the registry).
| Technique | Catalog method | Notes |
|---|---|---|
| Soft X-ray photoemission | angle_resolved_photoemission |
photoemission on the EXP endstations; reuses the angle_resolved_photoemission slug, a further consumer (TECH-1) |
A new technique regime on mostly familiar vocabulary¶
P04 is the fleet's soft X-ray spectroscopy beamline. Its energy regime is new (250-3000 eV, below the hard X-ray beamlines), and it forces the one genuinely new device binding, the GratingMonochromator (the soft X-ray analog of the crystal Monochromator). The techniques themselves reuse the xas_spectroscopy and angle_resolved_photoemission slugs already carried pending across the fleet, so neither forces a new Method to be coined now. The rest of the instrument anatomy reuses existing Families: the undulator binds InsertionDevice, the mirrors Mirror, the slits Slit, the manipulators Manipulator, the diagnostics Camera / FluxMonitor / Screen.
Not modelled yet¶
The concrete acquisition recipes (the photon-energy-scan sequences and their dwell times, the polarization switching, the photoemission analyzer sweeps) are not written yet; they join as the deployment approaches the point where CORA drives P04. Whether the soft X-ray Methods enter CORA's catalog is an owner-scope decision on Model; see Open questions for the world-facts to confirm first.