8-ID¶
X-ray Photon Correlation Spectroscopy (XPCS) beamline at APS. This page walks the operational core CORA models today across four stations. It is a reverse-engineered first cut, not yet a running model.
| Property | Value |
|---|---|
| Asset | 8-ID (root Asset, tier = Unit, parent_id = None) |
| Facility | APS (bound via facility_code = "aps", FacilityKind = Site) |
| Sector | Sector 8 (organizational grouping; not a registered Asset) |
| Status | First cut, reverse-engineered (operational core modelled; robotic sample changer and the softGlue timing graph deferred) |
| Sources | Two undulators on the S08ID straight section |
| Control stack | APS EPICS (the same floor as 2-BM); device handles bound from the beamline's instrument repo, carried confirm |
First cut, and confirm-pending by intent
This scaffold was reverse-engineered from the beamline's own Bluesky instrument repo (BCDA-APS/8id-bits); the extraction is in research/aps-reverse-engineering/. Like 4-ID it binds the real EPICS control handles, because 8-ID is operational. Every value is carried as confirm until 8-ID staff verify it. What CORA needs the team to confirm is on Open questions.
What makes 8-ID different¶
8-ID is the coherent-scattering beamline, and it is the deployment that earns 4-ID's new device classes into the catalog:
- Coherence and speed. XPCS measures intensity fluctuations of a coherent beam over time, so the detectors are fast area detectors (Eiger 4M, Lambda 2M, Rigaku 3M) gated by a softGlue FPGA timing fabric, downstream of an evacuated flight path.
- A second diffractometer. 8-ID-E carries a six-circle Huber diffractometer (mu, eta, chi, phi, nu, delta). Together with 4-ID's diffractometers this confirms the
Assembly(Diffractometer)shape. - Independent reuse of 4-ID's device classes. 8-ID has its own transfocators, LakeShore temperature controllers, and Sydor / TetrAMM beam-position monitors. The transfocators bind the graduated
Transfocatorcatalog Family (a CRL focusing optic) and the LakeShore controllers the graduatedTemperatureControllerFamily; the Sydor / TetrAMM beam-position monitors are still held loose pending a cross-facility gate-review (see Model).
It runs across four stations: 8-ID-A (optics), 8-ID-D (focusing), 8-ID-E (diffractometer endstation), 8-ID-I (XPCS endstation).
Scope: what is and is not modelled¶
| Part | In this cut | Why |
|---|---|---|
Optics + focusing (8-ID-A/D) |
Yes | Undulators, monochromator, FMBO mirrors, slits, the CRL transfocators |
Diffractometer endstation (8-ID-E) |
Yes | Six-circle Huber (binds the Goniometer Family) + temperature + beam-position monitor; the Assembly(Diffractometer) is in the catalog (DIFF-1) |
XPCS endstation (8-ID-I) |
Yes | Aerotech sample stages, the coherent area detectors, the flight path |
| UR5 robotic sample changer | No | A sample-changer shape CORA does not model yet (SAMPLE-2) |
| softGlue timing graph | Coarsely | One TimingController; the full FPGA signal graph is XPCS-3 |
The deferred parts are recorded on Model.
The beamline¶
- Source: the generated device walk: the undulators, the MN1 monochromator, the FMBO mirrors and slits, and the 8-ID-D CRL transfocators.
- Sample: the 8-ID-E six-circle diffractometer and the 8-ID-I XPCS sample stages (Aerotech, rheometer, temperature-controlled holders).
- Detector: the coherent area detectors, their stage, the flight path and beam stop, and the beam-position monitors.
Cutting across them:
- Controls: the EPICS control stack and the softGlue timing fabric; handles bound from the beamline config and carried confirm.
The cross-cutting reference view is the Inventory. The Source page is generated from the beamline.yaml descriptor.
Techniques¶
Techniques: what the modelled part of 8-ID is designed to do, as intent. XPCS and small-angle scattering are new to CORA's imaging-heritage catalog and render unlinked, carried pending.
Governance¶
Governance: who will act at 8-ID and the trust shape that gates their commands. People and agents are facility principals at the APS Site.
Model¶
Model: the developer's by-kind index, the catalog graduation that lands with this deployment, and the record of what is deliberately deferred.
Not yet documented¶
8-ID is not yet driven by CORA, so the operations runbook and the live experiment view are deliberately not written yet. They join as the deployment firms up. The 2-BM deployment shows the shape they will take.