Sample

The 19-BM-FACT in-air endstation. Design-phase; values are FDR design targets, and the manipulator design was out of FDR scope.

The sample stage sits in air in 19-BM-D. The beamline vacuum terminates at a water-cooled beryllium window (~50 m); a short rough-vacuum section protects that window from oxidation, then a Kapton window transitions to air. In the air gap the sample stage places the specimen in the white beam in front of the Detector.

Unlike the Detector, the sample stage is not modelled as a catalog Assembly here: it is a device group, not a composed blueprint. (2-BM models its sample positioning as a SampleTower Assembly + Fixture; 19-BM could earn the same once the manipulator firms and a scenario registers it.)

The model in one picture

The transition to air and the kinematic stack, base to sample (containment, Asset.parent_id). The precise sub-order firms with the mechanical design; the tree below is the design-layout intent.

19-BM  (Unit, Asset)
└── DEntryWindow  (Device, Window; water-cooled Be, 250 um, ~50 m; vacuum terminus)
    └── KaptonWindow  (Device, Window; transition to air)
        └── SampleRotary  (Device, RotaryStage; tomographic rotation, candidate trigger master)
            └── SamplePositioning  (Device, LinearStage; sample centring; hosts the robotic changer)

Endstation

The workhorse stack: a rotary stage carries the sample for tomographic rotation, with a linear positioning stage for centring. Both are in air. The SampleRotary is the candidate trigger master clock (see Controls). The manipulator design and its model bindings were out of FDR scope and are carried as questions.

Device	Family	Design spec (FDR)
SampleRotary	RotaryStage	tomographic rotation in air; candidate master clock for high-throughput triggering (STAGE-1, TRIG-1)
SamplePositioning	LinearStage	sample centring on the rotation stack; designed to host the robotic sample changer (STAGE-1, ROBOT-1)

Robotic sample changer

The endstation is designed to host a robotic sample-changing system: this is what makes 19-BM "Fast Autonomous CT", swapping samples without an operator so the beamline can run a high scan cadence. The detailed design is out of FDR scope, and the FDR records that the changer will undergo a separate safety review before implementation.

CORA models this when the design lands (ROBOT-1): the natural shape is one Positioner Asset that loads and unloads Subjects (a sample queue), with each load a mount rather than a new Fixture, gated by a Clearance that must be Active, issued after the safety review. None of that is built yet; the seam is reserved, not invented.

See Open questions for the stage and changer items still to confirm, and Inventory for the Asset tree.