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The beamline

The part of ESM CORA models today, as areas you can jump to: the optics and monochromator spine, the ARPES UHV sample, and the electron analyzer, plus the controls. First cut.

ESM is the NSLS-II Electron Spectro-Microscopy beamline at sector 21-ID. Its PV zones run XF:21IDA (front-end optics), XF:21IDB (the PGM), XF:21IDC (branch optics + exit slits), and XF:21ID1-ES / XF:21IDD-ES (the ARPES endstation). This cut models the operational core of the ARPES branch; the XPEEM/LEEM branch and the simulated devices are deferred (see Model).

Along the beam, in order, sit the stations: the Source that delivers, conditions, and energy-selects the beam, the Sample that orients the specimen in UHV at low temperature, and the Detector that records the photoelectrons. Cutting across them are the Controls. The stations are containment trees of apparatus (Asset.parent_id); controls relate to it sideways, by controller_id.

Stations

  • Source: the two EPUs, the front-end mirror M1 and the polarization diagnostic, the plane-grating monochromator and M3, and the KB refocusing pair M4A, the M4B mirror, and the resolution-defining exit slits.
  • Sample: the ARPES UHV cryostat sample manipulator and the cryostat temperature controller.
  • Detector: the hemispherical electron energy analyzer and the beam-current flux monitors.

Shared

  • Controls: the NSLS-II EPICS / ophyd control stack, and the bluesky-plan / queue-server orchestration CORA's edge replaces. The device handles are bound from the beamline's profile collection and carried confirm (CTRL-1).
  • Resources: the continuously-available supplies a run needs (photon beam, cooling water, vacuum for the UHV optics and endstation; cryogens for the cryostat); carried in the descriptor.

Reference

  • Inventory: the full planned CORA Asset model (every device by parent_id, with Families and pending confirmations). ESM graduates Manipulator, reuses the graduated GratingMonochromator, and introduces ElectronAnalyzer (since graduated by SST).