CHX¶
Coherent hard X-ray scattering at NSLS-II, beamline 11-ID: an X-ray photon correlation spectroscopy (XPCS) and small-angle-scattering beamline. This page describes how CORA would model and run CHX; the model is reverse-engineered from public configuration, not yet confirmed by CHX staff.
| Property | Value |
|---|---|
| Asset | CHX (root Asset, tier = Unit, parent_id = None) |
| Facility | NSLS-II (bound via facility_code = "nsls2", FacilityKind = Site) |
| Sector | Sector 11 (PV namespace XF:11ID*) |
| Institution | Brookhaven National Laboratory (context; not modeled as an Asset or Facility) |
| Status | Reverse-engineered from public config (design-phase scaffold) |
| Source | IVU20 in-vacuum undulator (SR:C11-ID:G1{IVU20:1}) |
How CORA would land on CHX
These pages describe how CORA would model, govern, and conduct CHX, the sixth NSLS-II beamline after FXI, HXN, BMM, SRX, and SIX. They are not a survey of the beamline's current software. The hardware facts (devices, EPICS PVs, axes) are read from public NSLS-II open source (the NSLS2/chx-profile-collection profile collection) and verified against it; vendor part numbers and physical positions are not in it, so they, and every read value, are carried confirm until CHX staff verify them (Open questions). This is a design-phase scaffold: the descriptor and these docs, with scenarios deferred.
The defining shape: coherence, a second time¶
CHX is the second coherent beamline CORA models. APS 8-ID brought XPCS first; CHX brings it at a second facility. The value to CORA is reinforcement: the coherent-beamline shape (an area detector recording a speckle time series under a fast-gated exposure) ports across facilities with no new vocabulary. CHX introduces no new catalog Family, and its techniques sit on the same deferred Methods 8-ID left pending.
XPCS measures the time correlations of a coherent speckle pattern to probe how a sample evolves, so it records long, fast time series on an area detector under a precisely gated exposure. CHX also runs static small- and wide-angle scattering (SAXS/WAXS) and grazing-incidence scattering (GISAXS) on the same detectors.
The beamline¶
Along the beam, in order:
- Source: the IVU20 undulator and the optics hutch (
11-ID-A), rendered as the generated source-stage device walk: the silicon and multilayer monochromators, the horizontal-deflecting mirror, the compound-refractive-lens transfocator, and the pink/mono-beam slits. - Sample: the endstation beam-defining and guard slits that condition the coherent beam, the grazing-incidence mirror for GISAXS, the sample stack positioned in the coherent focus, and the sample-environment thermal stage.
- Detector: the coherent area detectors that record the speckle time series, the SAXS detector positioner and beamstop, the flux counter, and the occasional fluorescence detector.
Cutting across all three:
- Controls: the Zebra trigger that gates the fast shutter and the detector frames for an XPCS time series, and the motion controllers.
The cross-cutting reference view is the Inventory.
Techniques¶
Techniques: the coherent-scattering techniques CHX runs (XPCS, SAXS/WAXS, GISAXS), each a Catalog Method, and why their Methods stay deferred (the 8-ID owner-scope cohort).
Governance¶
Governance: who may act at CHX and the trust shape CORA applies; CORA brings its own per-Actor authority.
Model¶
Model: the developer's by-kind index into where each CORA aggregate's CHX content lives.