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XrayAbsorptionCorrection v1

Summary

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

See Also

SetSample, SetSampleMaterial

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

Source

C++ header: XrayAbsorptionCorrection.h

C++ source: XrayAbsorptionCorrection.cpp