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The beamline

The part of XFP CORA models today, as areas you can jump to: the white-beam optics and dose-delivery gating, the solution sample stages and delivery pump, and the flux / dose monitors, plus the controls. First cut.

XFP (X-ray Footprinting of Biological Materials) is the NSLS-II dose-delivery beamline at sector 17-BM, a Case Western Reserve University partner beamline. It irradiates a biological macromolecule in solution with an intense white / pink beam to footprint it via hydroxyl radicals; the structural readout is done offline by mass spectrometry. Its PV zones run FE:C17B (the front-end white-beam slit), XF:17BM-OP / XF:17BMA-OP (the optics: the bendable mirror, the beamline slits), XF:17BMA-EPS / -PPS / -CT (the shutters), XF:17BM-BI (the flux and beam-position monitors), and XF:17BMA-ES:1 / ES:2 (the footprinting endstations: the filter wheel, the sample stages, the pumps) (ENC-1). 17-BM is a bending-magnet, white / pink beam source, with no monochromator in the footprinting path (SRC-1, WHITE-1).

Unlike every other beamline in the fleet, the stations here do not end in a detector that records a measurement. They end in a dose delivered to a sample, and a dose record; the structural readout is offline (see Detector). Along the beam, in order, sit the stations: the Source that conditions the white beam, sets the dose rate, and gates the timed dose; the Sample that flows or positions the solution sample in the beam; and the Detector, which here is the flux / dose monitoring (no imaging detector). 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 storage-ring machine state read through a loose StorageRing (MACHINE-1), the bendable front-end mirror (OPT-1), the white-beam and defining slits (OPT-2), the eight-position Al filter wheel that sets the dose rate (ATTN-1), and the dose-delivery gating, the personnel and timed shutters (PSS-1, DOSE-1) and the delay-generator dose timer that fires the millisecond Uniblitz fast shutter (DOSE-1).
  • Sample: the capillary-flow sample stage (SAMPLE-1), the high-throughput plate and shutterless HTFly stages (HT-1), and the sample-delivery pump (a loose FlowController, FLOW-1). The fraction collector, the pure-Python 96-well plate addressing, and the solution Subject are the sample-custody seam (FC-1, HT-1, SUBJECT-1).
  • Detector: the QuadEM flux monitor and the Sydor beam-position monitor that measure the delivered dose (DET-1, DIAG-1). There is no scattering, area, or imaging detector: the footprinting structural readout is offline mass spectrometry (READOUT-1).

Shared

  • Controls: the NSLS-II EPICS / ophyd control stack, the dose-delivery timing, the sample-custody seam, and the offline-readout seam (the run produces a footprinted sample plus a dose record; the mass spec is downstream). The device handles are bound from the beamline's profile collection and carried confirm (CTRL-1).
  • Resources: the continuously-available supplies a run needs (the photon beam, cooling water, and vacuum for the white-beam optics), plus the footprinting consumables (buffers, radical scavengers, the flow medium) as Supply; carried in the descriptor (SUP-1).

Reference

  • Inventory: the full planned CORA Asset model (every device by parent_id, with Families and pending confirmations), including the loose families and the FlowController held at n=4.