Sample¶
The endstation sample side: the two bound axes of the diffractometer, and the absent multi-circle diffractometer and in-situ environment. A deliberately partial first cut; PVs read from the NSLS2/isr-profile-collection startup files, carried confirm.
This page is where ISR's partial source shows most plainly. ISR's science, resonant scattering and surface / interface diffraction (crystal truncation rods), needs a multi-circle diffractometer: sample-orientation circles, a detector two-theta arm, and a reciprocal-space (hkl) engine. The public profile collection does not yet contain it. What it binds is two axes.
The sample side at a glance¶
| Asset | Family | PV | What it does |
|---|---|---|---|
SampleStage |
RotaryStage |
XF:04IDD-ES:1{Dif:ISD-Ax:th} |
the two bound axes of the Dif:ISD diffractometer: a sample rotation (th, the operative scan axis) and a second axis (zeta) (DIFF-1) |
What is bound, and what is not¶
The endstation IOC Dif:ISD ("Diffractometer, In-Situ Diffraction") binds exactly two axes in the profile collection: a sample rotation th and a second axis zeta (its rotary-versus-linear nature is not determinable from source). The beamline's plans confirm the minimal reality: the default scan is a one-dimensional rocking scan of th, and the attenuated scans step zeta. CORA models these as a single RotaryStage Asset (th is the operative rotation; zeta is carried as a second axis on the same Asset).
The IOC name (Dif:ISD) shows a diffractometer exists on the floor, but the source binds only these two of its axes. With no detector two-theta arm, no orientation circles (chi / phi / mu / eta / delta / gamma / nu), no sample translations, and no reciprocal-space engine in the source, there is no basis to scaffold a multi-circle Goniometer. So CORA carries one RotaryStage and routes the full diffractometer to an open question (DIFF-1), the same discipline the i20-1 (EDE) partial uses for its absent dispersive optics.
The in-situ environment is absent¶
ISR's name promises in-situ studies (electrochemistry, gas, temperature, cryostat). The profile collection binds none of it: there is no temperature controller, no potentiostat / electrochemistry, no gas / flow controller, and no cryostat anywhere in the source. The in-situ sample environment is a stated mission with zero device representation in the public source, so it is a named open question, not modelled (INSITU-1). When it lands, the environments would reuse existing families and the seam (a TemperatureController for thermal, a loose FlowController for gas / flow, the LIX / XFP precedent), with the sample itself a Subject; none is invented here.
Resonant and polarization, deferred¶
Resonant scattering needs a tunable energy axis near absorption edges, and often polarization analysis. The DCM Bragg (see Source) is the physical energy axis, but a wired energy pseudo-axis is only a non-functional stub in source, and no polarization analyzer or phase retarder is bound. So the resonant energy axis and polarization analysis are carried as an open question, not modelled (RESONANT-1). When wired, the energy axis would be a PseudoAxis over the DCM (the 2-BM beam-energy precedent) and any polarization hardware would reuse the loose PolarizationAnalyzer / PhaseRetarder families that APS 4-ID POLAR holds.
Why no new Family here¶
The one bound sample device reuses the catalog RotaryStage. CORA deliberately does not scaffold a Goniometer, an in-situ environment, or a resonant axis that the source does not contain; those are named open questions. Nothing here graduates and the catalog is unchanged.
See Open questions for the sample-side facts still to confirm, Inventory for the Asset tree, Model for the partial-scaffold rationale, and the source walk for the PVs as read from the profile collection.