6.4

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XrayAbsorptionCorrection v1

../_images/XrayAbsorptionCorrection-v1_dlg.png

XrayAbsorptionCorrection dialog.

Summary

Calculates attenuation of xrays produced by negative muons due to absorption in a sample for elemental analysis

Properties

Name Direction Type Default Description
InputWorkspace Input MatrixWorkspace Mandatory The name of the input workspace.
MuonImplantationProfile Input MatrixWorkspace Mandatory The name of the Muon Implantation Profile.
OutputWorkspace Output MatrixWorkspace Mandatory The name to use for the output workspace.
DetectorAngle Input number 45 Angle in degrees between beam and Detector.Range of normal values for detectors are : Ge1 : 90-180 , Ge2 : 270-360 , Ge3 : 0 - 90 , Ge4 : 180 -270.
DetectorDistance Input number 10 Distance in cm between detector and sample.

Description

This algorithm calculates the correction factors due to the absorption of Xrays by the sample. This is done by determining path of an xray from a muon in sample to detector and using the calculated distance travelled by emitted xray in sample to calculate correction factor using

\[\exp(-absorptionCoefficient(energy) \cdot distance) .\]

Input Workspace Requirements

The algorithm will compute the correction factors on a bin-by-bin basis for each spectrum within the input workspace. The following assumptions on the input workspace are made:

  • properties of the sample and optionally its environment have been set with SetSample
  • Xray Attenuation profile data is provided by using SetSampleMaterial
  • Muon Implantation Profile has a single spectrum. The x data is the muon depth in cm and the y data is intensity in counts.

Usage

Example: A cylindrical sample

CreateWorkspace(OutputWorkspace="Input", DataY=np.arange(0,8001), DataX=np.arange(0,8001))
CreateWorkspace(OutputWorkspace="MuonProfile", DataY=np.arange(1,51), DataX=np.linspace(0.1,0.2))
SetSample("Input", Geometry={"Shape": "Cylinder", "Height": 2.0, "Radius": 1.0,
             "Center": [0.0,0.0,0.0]})
SetSampleMaterial(InputWorkspace="Input", ChemicalFormula="Au",XRayAttenuationProfile="Gold_Xray_Absorption_Coefficient.dat")
XrayAbsorptionCorrection(InputWorkspace="Input", MuonImplantationProfile="MuonProfile",OutputWorkspace="corrections")
xdata = mtd["corrections"].readX(0)
ydata = mtd["corrections"].readY(0)
ylen = len(ydata)
print("The middle 5 correction factors in workspace are:")
for x in range(5):
        index = int(ylen/2) -3 + x
        print("Energy(Kev) : {0:.4f},Factor : {1:.4f}".format(xdata[index],ydata[index]))

Output:

The middle 5 correction factors in workspace are:
Energy(Kev) : 3997.0000,Factor : 0.9466
Energy(Kev) : 3998.0000,Factor : 0.9466
Energy(Kev) : 3999.0000,Factor : 0.9466
Energy(Kev) : 4000.0000,Factor : 0.9466
Energy(Kev) : 4001.0000,Factor : 0.9466

Categories: AlgorithmIndex | CorrectionFunctions\AbsorptionCorrections