CXI has two in-vacuum 2.3M CSPAD pixel-array detectors. Each detector is stationed downstream of one of CXI's three interaction points and can be read-out individually, together, or independently – allowing CXI the capability to operate two experiments simultaneously using a single X-Ray beam. When running two experiments during the same shift, the upstream experiment uses the DS1 CSPAD in the primary DAQ from cxi-daq, while the downstream parasitic experiment will use the DS2 CSPAD in the secondary DAQ from cxi-monitor. The names DS1 and DS2, refer to the vacuum chambers that contain the CSPAD detectors and a handful of motorized beamline components such as pulse pickers, beamstops, vacuum gauges, and alignment stages.
(Pic of DS1)
DS1 at the DSC location for SC1 experiments.
(Pic of CSPAD inside det chamber creepin around the corner all sneaky like)
Taking a look at the EPICS PV descriptions of the detector chamber motors, we can get an idea of what else is inside the chambers.
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EDM control GUIs for the detector chamber motors can be pulled up using the CXI Home Screen and clicking the "DS1" or "DS2" motor status groups as they appear under detector stand locations on the beamline map. Note that the motor control screens for the detector chamber motors are password protected and beamline staff have sworn a sacred oath to never speak the password ever to anyone ever. If an HXR staff member reveals the password to you, please report them to Sebastien Boutet so he may take punitive action.
(screenshot of CXI home and DS1 embedded motor screen)
DS1 DS1 and DS2 have companion mobile equipment racks, named D50 and D51 respectively. The racks are nearly identical twins and each contain power supplies and readout electronics for detectors, a Digi, a 4-channel stepper motor controller, an EPICS IOC server, and (whatever else). They handle controls and feedback for detector power and diagnostics, some stepper motor control, and serve as an interface for detector data and timing input/output.
(picture of a mobile rack and probably should make rack profiles)
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| Mobile Detector Rack Profile | |
|---|---|
| CSPAD Concentrator | Handles CSPAD data readout |
| Detector PDU | Consolidates power from MPOD with other analog control and timing signals to detector input |
| MPOD | EPICS controllable High/Low voltage power supply for detectors |
| EPICS IOC Server | IOC for motors, encoders and power supplies running from the mobile rack |
| Digi Serial Port Server | Serial communication input/output terminal |
| Dumb Motor Controller | For in-vacuum LS-180 CSPAD Z-stage |
| 120V AC Power Supply | Power supply for mobile rack electronics |
| Motor Power Supply | Power supply for dumb motors |
When a detector chamber changes locations, such as when DS2 moves from DSD to DSA, The mobile racks are powered down, IOCs disabled, and the detector chambers external electronics are unplugged. When it is mounted at its new location, the cables need to be reconnected and the mobile rack will need to be set up again and their IOCs restarted. The CXI Home Screen will also need to be edited.
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