Detector¶
The simultaneous SAXS and WAXS area detectors, the camera-length stage, the beamstops, and the diagnostics. PVs verified against startup/smibase/pilatus.py, beamstop.py, electrometers.py, amptek.py, prosilica.py.
SMI's measurement is the scattering pattern on two Pilatus detectors read at once: the SAXS detector down an in-vacuum flight path for low Q, the WAXS detector on a swing arc for wide Q. Reading both together is the routine mode.
| Asset | Family | PV | Role |
|---|---|---|---|
SAXSDetector |
Camera | XF:12ID2-ES{Pilatus:Det-2M} |
Pilatus 2M, low-Q (SAXS) |
WAXSDetector |
Camera | XF:12IDC-ES:2{Det:900KW} |
Pilatus 900KW on a swing arc, wide-Q (WAXS) |
SAXSDetectorStage |
LinearStage | XF:12IDC-ES:2{Det:1M-Ax:} |
sets the SAXS camera length (Q) |
SAXSBeamStop |
BeamStop | XF:12IDC-ES:2{BS:SAXS} |
blocks the SAXS direct beam |
FluxMonitor |
FluxMonitor | XF:12ID:2{EM:Tetr1} |
I0 normalization |
FluorescenceSpectrometer |
EnergyDispersiveSpectrometer | XF:12IDC-ES:2{Det-Amptek:1} |
element-sensitive Amptek MCA |
BeamViewingCamera |
Camera | XF:12IDC-BI{Cam:SAM} |
on-axis sample viewing |
Two detectors, one measurement; the camera length¶
The SAXSDetector (Pilatus 2M) sits down the in-vacuum flight path; the SAXSDetectorStage Z axis translates it to set the sample-to-detector camera length and hence the accessible Q. The WAXSDetector (Pilatus 900KW) rides a swing arc (XF:12IDC-ES:2{WAXS:1-Ax:Arc}): swung out for GISAXS, brought to zero for GIWAXS. The two are read at once, with their own beamstops blocking each direct beam (the SAXSBeamStop is a four-motor rod-and-pin-diode assembly; the WAXS detector has its own beamstop). Simultaneous SAXS+WAXS is modelled as coordinated Runs under one Campaign, not a third combined technique.
Reuse, not new vocabulary¶
This is the reinforcement point of SMI as a CORA exercise: a scattering beamline with two area detectors, a camera-length stage, two beamstops, and a fluorescence channel that needs no new Family. The Pilatus detectors reuse Camera (the Eiger-to-Camera precedent at CHX and the i22 Detector-Role shape); the flux monitor reuses FluxMonitor (graduated in #353); the beamstops reuse BeamStop; the Amptek reuses EnergyDispersiveSpectrometer (graduated in #345). The detector chain is the same shape Diamond I22 carries (two Pilatus detectors at once distinguished by camera length); SMI shows it porting to a second facility, with the grazing-incidence swing arc added.