Detector

The 19-BM-FACT indirect-detection imaging system, and the downstream beam stops. Design-phase; the detector hardware is procured after the FDR.

19-BM records 2-D projections with an indirect-detection system: a scintillator converts the transmitted X-ray image to visible light, visible-light microscope optics relay it, and a camera captures the frames, which are reconstructed off-line into 3-D micron-resolution tomograms. The system sits in air, downstream of the sample in 19-BM-D.

The specific scintillator, microscope optics, and camera are chosen after the FDR (DET-1); the shapes below are the design intent.

The model in one picture

What holds what, downstream of the sample (containment, Asset.parent_id):

19-BM  (Unit, Asset)
└── DetectorStage  (Component, Family Table; positions the system in air)
    └── Microscope  (Component, Family Housing; anchors the Microscope Assembly, presents the Detector Role)
        ├── Scintillator  (Device, Scintillator; X-ray to visible)
        └── Camera        (Device, Camera; records projections)

The microscope chassis is a Housing that anchors the cross-facility Microscope Assembly, the same blueprint 2-BM uses: a scintillator and visible-light optics presenting the Detector Role. The Microscope itself is an Assembly, not a Family, so the chassis binds the Housing Family (matching 2-BM and TomoWISE). No Fixture is registered yet (19-BM is design-phase, and no scenario binds Assets to slots), so this is the planned composition, not a materialized Fixture.

Detector

Device	Family	Design spec (FDR)
DetectorStage	Table	positions the indirect-detection system in air, downstream of the sample; axis layout TBD
Scintillator	Scintillator	converts the X-ray projection to a visible-light image; selection TBD (DET-1)
Microscope	Housing (Microscope Assembly)	visible-light relay optics chassis presenting the Detector Role; selection TBD (DET-1)
Camera	Camera	records 2-D projections for off-line reconstruction; selection TBD (DET-1)

Downstream beam stops

At the downstream wall of 19-BM-D, the white beam is absorbed and the station is shielded to the standard required for a white-beam BM station.

Device	Family	Design spec (FDR)
PhotonStop	BeamStop	A359-M100, water-cooled copper; water in series with the upstream Be window, BLEPS-monitored
BremsstrahlungStop	BeamStop	A359-K3, chevron stack of lead bricks, behind the photon stop
DownstreamGuillotines	Shielding	two movable Pb guillotines (>= 12 mm each), the 1 x 1 m2 extra-lead area required by APS TB-44; one held open during operation

Families

The active detector families are reused, none new: Table (the detector stage), Housing (the microscope chassis), Scintillator, and Camera, composed through the cross-facility Microscope Assembly. The beam stops reuse the catalog BeamStop Family (graduated under the passive beam-path tier); the guillotines bind the loose Shielding family, which renders as plain text (not yet in the catalog).

The detector hardware selections and the trigger path are the main detector-side open questions. See Inventory for the Asset tree.