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DiffractionEventCalibrateDetectors v1

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Summary

This algorithm optimizes the position and angles of all of the detector panels. The target instruments for this feature are SNAP and TOPAZ.

See Also

AlignComponents

Properties

Name	Direction	Type	Default	Description
InputWorkspace	Input	EventWorkspace	Mandatory	The workspace containing the geometry to be calibrated.
Params	Input	string		A comma separated list of first bin boundary, width, last bin boundary. Optionally this can be followed by a comma and more widths and last boundary pairs. Use bin boundaries close to peak you wish to maximize. Negative width values indicate logarithmic binning.
MaxIterations	Input	number	10	Stop after this number of iterations if a good fit is not found
LocationOfPeakToOptimize	Input	number	2.0308	Optimize this location of peak by moving detectors
DetCalFilename	Input	string	Mandatory	The output filename of the ISAW DetCal file. Allowed extensions: [‘.detcal’]
BankName	Input	string		Optional: To only calibrate one bank. Any bank whose name does not match the given string will have no events.

Description

Moves the detectors in an instrument to optimize the maximum intensity of each detector using gsl_multimin_fminimizer_nmsimplex. Only bin data close to peak you wish to maximize.

Usage

Example: move detectors to maximize intensity

import os
ws = CreateSampleWorkspace("Event",NumBanks=1,BankPixelWidth=1)
ws = MoveInstrumentComponent(Workspace='ws', ComponentName='bank1', X=0.5, RelativePosition=False)
wsD = ConvertUnits(InputWorkspace='ws',  Target='dSpacing')
maxD = Max(wsD)
#Peak is at 2.69 in dSpace
DiffractionEventCalibrateDetectors(InputWorkspace='ws', Params = "2.6, 0.001, 2.8",
    LocationOfPeakToOptimize=2.67, BankName="bank1", DetCalFilename="Test.DetCal")
LoadIsawDetCal(InputWorkspace='ws',Filename=os.path.join(config["defaultsave.directory"], 'Test.DetCal'))
ws = ConvertUnits(InputWorkspace='ws',  Target='dSpacing')
maxA = Max(ws)
print("Peak in dSpace {:.11f}".format(0.5*(maxD.readX(0)[0]+maxD.readX(0)[1])))
print("Peak from calibration {:.11f}".format(0.5*(maxA.readX(0)[0]+maxA.readX(0)[1])))

Output:

 Peak in dSpace 2.6...
 Peak from calibration 2.6...

Categories: AlgorithmIndex | Diffraction\Calibration | CorrectionFunctions\InstrumentCorrections

Source

C++ header: DiffractionEventCalibrateDetectors.h

C++ source: DiffractionEventCalibrateDetectors.cpp