7-BM¶
A multi-technique flow and combustion imaging beamline at APS. This page walks the beamline as it is being designed; everything here is taken from the 7-BM operations docs or inferred, not a commissioned measurement.
| Property | Value |
|---|---|
| Asset | 7-BM (root Asset, tier = Unit, parent_id = None) |
| Facility | APS (bound via facility_code = "aps", FacilityKind = Site), Sector 7 |
| Status | In design (recommissioning for APS-U) |
| Techniques | high-speed imaging, radiography, tomography, energy-dispersive diffraction, fluorescence |
| Beam modes | white, monochromatic (DMM, 6 to 18 keV), focused (KB mirrors) |
| Control stack | APS EPICS, the same stack 2-BM uses |
Design phase
7-BM is being recommissioned and its operations documentation is partial (empty technique stubs, "to be completed once APS-U operation starts"). Every value on these pages is taken from the docs or inferred, carried as confirm until 7-BM staff verify it. The things CORA still needs the team to confirm are collected on Open questions; they are long on purpose.
What makes 7-BM a different shape from the 2-BM pilot¶
2-BM is a single-technique micro-CT beamline. 7-BM is the opposite: one beamline hosting several techniques over partly-shared apparatus, with a sample environment 2-BM has nothing like.
- Multiple techniques, multiple beam modes. High-speed imaging and energy-dispersive diffraction run white beam; radiography runs a focused beam; tomography runs monochromatic. The beam mode is a per-technique choice, not a fixed source property.
- Detector modalities beyond the 2D camera. A germanium energy-dispersive detector records a per-photon spectrum; a PIN photodiode reads point intensity for time-resolved radiography; a high-speed camera captures chopper-gated movie bursts. All three present shapes the 2-BM camera path never needed.
- A flow and combustion sample environment. A compressed-air plant, a vacuum system, and metered process gases serve flow and combustion experiments, with a heavier hazard surface (flammable gas, fuel vapor, oxygen deficiency).
- A heterogeneous floor. Several technique-specific orchestrators (tomoScan, DataGrabber, the digitizer Python scripts, the EPICS scan record) coexist, where 2-BM has one.
What 7-BM does not change: the tomography path reuses the 2-BM model unchanged (the same tomoScan engine and the same Methods), and the APS Site envelope is reused rather than created.
The beamline¶
The systems in three areas the beam passes through, plus the controls that drive them. See the beamline overview for how the areas relate.
Along the beam, in order:
- Source: the source, the front-end and beam-conditioning optics (filters, the rotary chopper, white-beam slits), the energy-selecting and focusing optics (the double multilayer monochromator, the multilayer mirror, the KB pair), and the safety shutters, rendered as the generated source-stage device walk.
- Sample: the experiment hutch, the tomography rotation and sample positioning, the energy-dispersive gauge slits, and the flow and combustion sample environment.
- Detector: the several detector modalities, an imaging camera, a high-speed camera, a point photodiode, and the energy-dispersive detector.
Cutting across all three:
- Controls: the EPICS control stack and the DG645 timing and triggering scheme.
The cross-cutting reference view is the Inventory: the planned Asset tree by parent_id with families and the values still pending confirmation. The Source page is generated from the beamline.yaml descriptor.
Techniques¶
Techniques: what 7-BM is designed to do, as design intent. Each is a portable Catalog Method that an APS Practice would adapt once the technique is in the pilot scope.
Governance¶
Governance: who will act at 7-BM 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 into where each CORA aggregate's 7-BM content lives.
Not yet documented¶
7-BM is pre-build for CORA, so the operations runbook (procedures, recipes, cautions) and the live experiment view are deliberately not written yet: a runbook for an unmodelled beamline would be invention, not record. They join these pages as the techniques enter the pilot scope. The 2-BM deployment shows the shape they will take.