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Open questions

What CORA needs the 4-ID POLAR team to confirm before the model can be trusted.

4-ID POLAR was reverse-engineered from the beamline's own Bluesky instrument repo (BCDA-APS/polar-bits), so the control handles in the Inventory are the beamline's real PVs, but read from a config snapshot rather than confirmed by staff. Each row below is a fact the beamline team owns, not a CORA modelling choice (those are recorded on Model instead, including which loose Families graduate and the diffractometer Assembly). It is a delete-on-answer queue: when an item is answered, the answer lands in the descriptor and the row is removed, with the reason in the commit. Priorities are Blocks-build (the answer changes the structure of the model), Blocks-go-live (a placeholder is fine for the description, but the real value is needed before CORA observes or drives the hardware), and Nice-to-have.

Topology and scope

ID Priority Question CORA assumes Resolves
TOPO-1 Blocks-build Do the three experiment stations (4-ID-B, 4-ID-G, 4-ID-H) run off one beam in series, or are any canted / branched off separate beams? Which optics are shared versus per-station? One root Unit Asset 4-ID POLAR with one optics spine feeding the three stations; KB mirrors and filters are per-station. One-vs-many beam walks and the shared-vs-per-station optics split in the descriptor.
TOPO-2 Blocks-go-live The 4-ID-Raman station: what instruments and devices does it carry? (Its devices.yml is a symlink that did not resolve in the source clone, so it did not extract.) The Raman station exists but is out of this cut. The Raman station devices and a fifth enclosure if warranted.
TOPO-3 Nice-to-have Two PVs gave ambiguous station hints: 4iddMZ0: (the SGZ Vortex detector) and 4idkepco: (a Kepco magnet supply). What station does each sit in? The Vortex is placed at 4-ID-G and the Kepco magnet at 4-ID-G, both confirm. No 4-ID-D / 4-ID-K enclosures are declared. The station assignment for those two devices.

Control and safety

ID Priority Question CORA assumes Resolves
CTRL-1 Blocks-go-live Are the EPICS PV handles read from the polar-bits config current and correct for each device? The handles in the descriptor are taken from the config and carried confirm. Verifying each Asset's control handle.
PSS-1 Blocks-go-live What are the PSS search-and-secure permit signals for the four hutches (4-ID-A/B/G/H)? Four hutches exist with permit signals to be named. The Enclosure permit signals.

Sources and optics

ID Priority Question CORA assumes Resolves
SRC-1 Blocks-go-live The undulator pair on S04ID: device types, periods, and gaps. One InsertionDevice Asset for the pair (PolarUndulatorPair); periods unconfirmed. The insertion-device specs.
SRC-2 Nice-to-have Should the pair be one Asset or two (one per undulator)? Modelled as one Asset. One-vs-two source Assets.
MONO-1 Blocks-go-live The VDCM monochromator: energy range, crystal set behind crystal_select, and per-axis roles. One Monochromator Asset (4idVDCM) with a crystal-select axis; range unconfirmed. The monochromator energy model.
OPT-1 Nice-to-have The toroidal pre-focusing mirror and the HHL bendable mirror: coatings, stripes, and the bender / piezo axis roles. Two Mirror Assets; the HHL axis map is taken from the config, coatings unconfirmed. The mirror specs.
OPT-2 Blocks-go-live The transfocator (4idPyCRL:CRL4ID:): lens material, count, and which stations it focuses. One Transfocator Asset (catalog Family); serves 4-ID-G and 4-ID-H. The transfocator spec.
OPT-3 Nice-to-have The per-station KB mirror (bkb/gkb/hkb) internal axis maps. Three Mirror Assets; only the 4-ID-B KB carries a partial axis map. The KB axis maps.

Polarization

ID Priority Question CORA assumes Resolves
POL-1 Blocks-go-live The three phase retarders (pr1/pr2/pr3): diamond crystal type, thickness, and how they coordinate to set a polarization state. Three PhaseRetarder Assets (loose Family), each th/x/y, energy-tracking. The phase-retarder specs and the polarization-state model.
POL-2 Blocks-go-live The polarization analyzer (pol, th/y): analyzer crystal and the scattered-beam polarization it resolves. One PolarizationAnalyzer Asset (loose Family) at 4-ID-B. The analyzer spec.

Diffractometer

ID Priority Question CORA assumes Resolves
DIFF-1 Blocks-build The Huber Eulerian and high-pressure diffractometers: the real circle set (4-circle Eulerian? 6-circle?) and which motor is which circle (omega, chi, phi, two-theta). Two diffractometers modelled as plain devices with the config's axis maps; the circle roles are partial. The circle geometry, which decides the Assembly(Diffractometer) slot shape (see Model).
DIFF-2 Blocks-go-live The reciprocal-space coordination: is hklpy2 driving an (h, k, l, energy) pseudo-axis, and over what geometry? A reciprocal-space PseudoAxis is assumed for the Assembly design; not yet a device. The pseudo-axis model.

Sample environment

ID Priority Question CORA assumes Resolves
MAG-1 Blocks-go-live The sample magnets: the two 2 T magnets (bmag/emag) and the high-field magnet (magnet911) field ranges and control PVs (the 2 T magnets had no control PV in the config), and the Kepco-driven gmag. Four Magnet Assets (loose Family); fields and several PVs unconfirmed. The magnet specs and handles.
TEMP-1 Nice-to-have The LakeShore 336 and 340 controllers: sensor channels and the sample stages they regulate. Two TemperatureController Assets (catalog Family, presents Regulator) at 4-ID-G. The temperature-controller model.
SAMPLE-1 Nice-to-have The Ventus laser at 4-ID-H: is it a pump-probe source CORA should model as a device, or only carry as a Clearance hazard? One Laser Asset (loose Family); modelling-versus-hazard is open. The laser model or hazard treatment.
SAMPLE-2 Nice-to-have The preamplifiers, lock-in (srs810), and high-pressure-cell controllers (Pace PC1/PC2) are in the config but not modelled here. Which are beamline equipment versus user-brought? Deferred as peripheral. Whether these become Assets.

Detector

ID Priority Question CORA assumes Resolves
DET-1 Blocks-go-live The Eiger area detector model, sensor, and frame rate. One Camera Asset (4idEiger:); model unconfirmed. The detector Model binding.
DET-2 Nice-to-have The SGZ Vortex (4iddMZ0:): is it a fluorescence / energy-dispersive point detector, and what Family fits? Bound to a loose BeamPositionMonitor Family as a placeholder; classification unconfirmed (see TOPO-3). The Vortex classification and Family.

Beam-position monitors and supplies

ID Priority Question CORA assumes Resolves
BPM-1 Nice-to-have The XBPMs, Sydor electrometers, and TetrAMM: which are true beam-position monitors versus intensity (I0) normalizers? All bound to a loose BeamPositionMonitor Family presenting the Sensor Role. The monitor classification.
SUP-1 Nice-to-have The cryogen and process-gas supplies the magnet and low-temperature environments draw on. Liquid helium and liquid nitrogen carried pending in the descriptor. The Supply records.