VMXm: fast grid scans

[Tom-Willemsen]

Umbrella issue for fast grid scans on VMXm - subtickets to be created as work becomes clearer.

Simple fast grid scans, 2D scan at a single rotation angle, heatmaps not needed in GDA but would be liked in ispyb.

Queries/outstanding work:

• Fast shutter control currently being done in geobrick motion program, may make more sense for GDA/bluesky to do this.
  • Two shutters - fast & slow - need coordinating correctly.
• Still need to figure out exactly how VMXm's zebra is set up and demo a fast grid scan running & triggering the detector but setting everything up manually rather than through GDA/bluesky.
  • Scientist to add meeting next week about this.
• Metadata:
  • aperture_scatterguard, flux, s4_slits, undulator, xbpm - not required or don't make sense for VMXm.
  • backlight just needs moving out, nothing else.
  • attenuator would be good to include on VMXm.

VMXm scientists have said they would like some basic functionality by 20th Nov as they have scheduled an experiment that would benefit from this...

Edit RT 2026-05-05:
PRs:

• Allow doing gridscans with generic number of grids #1623
• Add devices for VMXM ispyb gridscan info dodal#1925
• Add vmxm gridscan plan #1636
• Ispyb integration vmxm grid scan #1653
  Issues:
• Refactor nexus callbacks to be generic #364
• Make 'create_detector_parameters' more generic #306
• 2D grid scans shouldn't care about Y steps being odd #288
• VMXm testing gridscan testing notes #1248 - a number of hotfixes applied in scratch folder that should be merged
• Grid scans: Refactor parameters #1634

JIRA issue with longer-term gridscan goals: https://jira.diamond.ac.uk/browse/VMXM-200

Comment history below this initial summary retained only for historical purposes, all current work to be tracked in GH issues temised above.

[DominicOram]

Thoughts on how we do this:

• Test that we can manually trigger and get images with hardware
• Create a VMXm in dodal with these devices - VMXm: Add devices for fast grid scan dodal#207
• Wholesale copy flyscan_xray_centre_plan.py - See Initial VMXm FGS plan hyperion#942
• Remove bits we don't think are necessary - See Initial VMXm FGS plan hyperion#942
• Get to the point we can manually run the copied one (outside GDA)
• Work out where to integrate with GDA

[Tom-Willemsen]

#!/bin/sh

# Fast Grid Scan Interface
caput BL02J-MO-SAMP-11:FGS:P1404:X_NUM_STEPS            10
caput BL02J-MO-SAMP-11:FGS:P1407:Y_NUM_STEPS            8
caput BL02J-MO-SAMP-11:FGS:P1406:X_STEP_SIZE            0.005
caput BL02J-MO-SAMP-11:FGS:P1409:Y_STEP_SIZE            0.005
caput BL02J-MO-SAMP-11:FGS:P1401:EXPOSURE_TIME          180   # Exposure or Acquisition Time in ms
caput BL02J-MO-SAMP-11:FGS:P1420:FAST_SHUTTER_OPEN_TIME 71    # Fast Shutter opening time in ms
caput BL02J-MO-SAMP-11:FGS:P1405:X_START                -0.2
caput BL02J-MO-SAMP-11:FGS:P1408:Y_START                 0.5
caput BL02J-MO-SAMP-11:FGS:P1410:Z_START                -0.2
caput BL02J-MO-SAMP-01:OMEGA.VAL                         100.0

sleep 2

# Eiger
caput BL02J-EA-EIGER-01:CAM:AcquireTime   0.18
caput BL02J-EA-EIGER-01:CAM:AcquirePeriod 0.18
caput BL02J-EA-EIGER-01:CAM:NumTriggers   80    # Number of grid points
caput BL02J-EA-EIGER-01:CAM:ManualTrigger Yes
caput BL02J-EA-EIGER-01:CAM:NumExposures  1
caput BL02J-EA-EIGER-01:CAM:NumImages     1
caput BL02J-EA-EIGER-01:CAM:ImageMode     Continuous
caput BL02J-EA-EIGER-01:CAM:TriggerMode   "External Enable"

sleep 2

# ODIN
caput BL02J-EA-EIGER-01:OD:NumCapture     80   # Number of grid points
caput -S BL02J-EA-EIGER-01:OD:FilePath    /dls/mx/data/cm33865/cm33865-4/ajf67
caput -S BL02J-EA-EIGER-01:OD:FileName    test5

# Zebra
caput BL02J-EA-ZEBRA-01:OUT4_TTL          1    # Set the detector trigger output = trigger input from motion program

sleep 2

# Start ODIN and Eiger
caput BL02J-EA-EIGER-01:OD:Capture        1
caput BL02J-EA-EIGER-01:CAM:Acquire       1

sleep 2

# Start the scan
caput BL02J-MO-SAMP-11:FGS:RUN.PROC 1

[Tom-Willemsen]

Note: fast shutter will be controlled by motion controller directly (hence the FAST_SHUTTER_OPEN_TIME and related parameters above). Slow shutter control should be done by hyperion.

[Tom-Willemsen]

With DiamondLightSource/dodal#211 and DiamondLightSource/hyperion#942 I think we are close to the point where we should test this on the beamline manually as above (not integrating with GDA yet - but just prove we can set off a sensible-looking FGS from bluesky).

The new plan is messy and duplicates a lot from the i03 version, once we're happy with how it works on VMXm we should consider:

• What is generic/instrument specific
  • Do the refactoring to reduce duplication
• Where this plan should live - if hyperion is meant for UDC long-term, then maybe the VMXm one should be in mx_bluesky
  • If so, where do we store any common components etc

[olliesilvester]

There are a number of issues which need compleition before this can be merged, see:
DiamondLightSource/hyperion#942 and
DiamondLightSource/dodal#211