3.12

SANSBeamFluxCorrection v1

../_images/SANSBeamFluxCorrection-v1_dlg.png

SANSBeamFluxCorrection dialog.

Summary

Performs beam flux correction on TOF SANS data.

Properties

Name Direction Type Default Description
InputWorkspace Input MatrixWorkspace Mandatory Workspace to be corrected
InputMonitorWorkspace Input MatrixWorkspace Mandatory Workspace containing the monitor counts for the sample data
ReferenceFluxFilename Input string Mandatory File containing the reference flux spectrum. Allowed extensions: [‘_event.nxs’, ‘.nxs’, ‘.nxs.h5’]
ReductionProperties Input string __sans_reduction_properties  
OutputWorkspace Output MatrixWorkspace Mandatory Corrected workspace.
OutputMessage Output string    

Description

Performs beam flux correction for TOF SANS data.

The correction goes as follows:

I({\lambda}) = I_0({\lambda}) / \Phi_{sample}

where

\Phi_{sample} = \frac{M_{sample}}{M_{ref}} \Phi_{ref}

Usage

Example - Performing a Beam Flux Correction on Dummy Data

# Create some dummy data, as well as a dummy monitor ws for EQSANS.
x = [1,2,3,4,5,6,7,8,9,10,11]
y = 491520*[0.1]
ws = CreateWorkspace(DataX=x,DataY=y,DataE=y,NSpec='49152',UnitX='Wavelength')
LoadInstrument(ws, InstrumentName="EQSANS", RewriteSpectraMap=True)
monitor = SumSpectra(ws)

# Do the correction, dragging in the file which contains the reference flux spectrum.
corrected = SANSBeamFluxCorrection(ws, InputMonitorWorkspace=monitor, ReferenceFluxFilename="SANSBeamFluxCorrectionMonitor.nxs")

print("The expected value of each bin should be {:.11e}.".format(0.1/(49152*0.1)/(49152*0.1)))
print("The actual value of the first bin is {:.11e}.".format(corrected[0].readY(0)[0]))

Output:

The expected value of each bin should be 4.13921144274e-09.
The actual value of the first bin is 4.13921144273e-09.

Categories: Algorithms | Workflow\SANS\UsesPropertyManager | CorrectionFunctions\InstrumentCorrections

Source

C++ source: SANSBeamFluxCorrection.cpp (last modified: 2016-11-01)

C++ header: SANSBeamFluxCorrection.h (last modified: 2016-06-07)