Beamline Energy Implementation

(Work In Progress)

Reverse Engineer from GDA

Currently beamline energy is controlled in GDA from within beamlineSpecificEnergy.py

There is a class beamLineSpecificEnergy which inherits from beamLineEnergy

To do the alignment there are two implementations AutomatedAlign and QuickAlign

in beamLineEnergy it basically does the equivalent of

	def align_beam(self, quick_align): # Re-align button
			if quick_align:
				self.QuickAlign()
			else:
				self.energyController.moveTo(self.getPosition())
				self.align_beam_worker()

• The entry point for setting the energy is in beamLineEnergy.asynchronousMoveTo which overrides the asynchronousMoveTo in Scannable. ScannableMotionBase delegates moveTo to the async version.
• asynchronousMoveTo ultimately calls asynchronousMoveTo_worker in beamLineSpecificEnergy
• asynchronousMoveTo_worker performs a number of operations all on separate threads and then waits for them to finish
  • asynchronousMoveTo_worker creates a MoveVfmThread instance, which initialises VFM_X and VFM_Y stripe according to both the current and requested energy.
  • asynchronouseMoveTo_workersets the focus mode Not sure if we need to implement this
  • asynchronouseMoveTo_workersets detector energy Don't think we need to do this
  • asynchronouseMoveTo_workersets energy in ChangeEnergyThread, this is where it sets BeamLineEnergy_Bragg_eV and then calls energyController.moveTo()
  • asynchronouseMoveTo_worker calls mirrorFocus.check_voltages() (when and if depends on factors)
  • asynchronouseMoveTo_worker calls align_beam_worker() in the superclass which delegates to align_beam_specific_worker()
  • asynchronouseMoveTo_worker keeps all its async threads tracked in energy_threads array and waits for them to complete at the end of the func

align_beam_specific_worker()

• Open the experiment shutter
• Read initial state (Think this is what setParameters does)
• close camera shutter
• set attenuator transmission
• disable feedback loop
• set roll converter to target value
• If full XBPM feedback
  • find peak gaussian strategy #1
• else
  • find peak gaussian strategy #2
• set slit size
• reset attenuation
• reenable feedback loop

AutomatedAlign

• is referenced by HandleCollectRequests in do_automated_align() but the latter appears to be unused

QuickAlign

• not referenced by anything but is probably a manual entry point