Sample¶
The diffractometers and sample environment across 4-ID-B / G / H. First cut; PVs read from the beamline config, carried confirm.
The sample stage at POLAR is not a single endstation but a set of per-station systems: the Huber diffractometers at 4-ID-G that orient a crystal and scan reciprocal space, the polarization analyzer at 4-ID-B, and the sample environment (superconducting magnets, temperature controllers, positioning tables, a pump-probe laser) spread across the experiment stations. They are modelled as sample-stage groups in the descriptor.
The diffractometer devices bind the catalog Goniometer Family for their sample circles; the composed Assembly(Diffractometer) is in the catalog (materialized by the 8-ID Fixture scenario), and a 4-ID Fixture is the follow-on (see Model). The polarization, magnet, temperature, and laser device classes are bound to loose Family strings, not catalog Families, pending graduation.
The diffractometers (4-ID-G)¶
POLAR's diffraction core: a Huber Eulerian-cradle diffractometer and a high-pressure diffractometer. Each orients a single crystal through its circles while the detector records the scattered intensity; the reciprocal-space (h, k, l) coordination runs through hklpy2.
| Device | Family | Design spec / note |
|---|---|---|
Diffractometer_Euler |
Goniometer |
Huber Eulerian cradle; sample x/y/z mapped, circle roles partial (DIFF-1) |
Diffractometer_HighPressure |
Goniometer |
high-pressure diffractometer; chi/phi/sample-tilt + x/y/z mapped (DIFF-1) |
PolarizationAnalyzer |
PolarizationAnalyzer (loose) |
analyzer crystal stage (th/y) at 4-ID-B; resolves scattered polarization (POL-2) |
The circle geometry (4-circle Eulerian versus 6-circle, and which motor is which circle) is DIFF-1; it decides the Assembly(Diffractometer) slot shape. The reciprocal-space pseudo-axis is DIFF-2.
Sample environment¶
POLAR's magnetic-scattering signature: applied field and low temperature at the sample, plus a pump-probe laser.
| Device | Family | Design spec / note |
|---|---|---|
Magnet_2T_B, Magnet_2T_E |
Magnet (loose) |
2 T sample magnets at 4-ID-B; control PVs not in the config (MAG-1) |
Magnet_9T_H |
Magnet (loose) |
high-field magnet at 4-ID-H (MAG-1) |
Magnet_Kepco_G |
Magnet (loose) |
Kepco-driven electromagnet; station a guess (TOPO-3, MAG-1) |
TemperatureController_336/340 |
TemperatureController |
LakeShore 336 / 340 controllers at 4-ID-G; catalog Family, presents Regulator (TEMP-1) |
SampleTable_B, SampleTable_H |
Table |
per-station sample positioning tables |
PumpProbeLaser |
Laser (loose) |
Ventus laser at 4-ID-H; model-versus-hazard open (SAMPLE-1) |
SampleSlit_B/G/H |
Slit |
per-station sample-defining slits |
The high-pressure cell controllers and the preamplifiers that read the sample signal are present in the config but not modelled in this cut (SAMPLE-2).
See Open questions for the diffractometer, magnet, and laser facts still to confirm, and Inventory for the Asset tree.