Table of Contents
Calculates absorption corrections for a cylindrical or annular sample using Paalman & Pings format.
Name | Direction | Type | Default | Description |
---|---|---|---|---|
SampleWorkspace | Input | MatrixWorkspace | Mandatory | Name for the input Sample workspace. |
SampleChemicalFormula | Input | string | Mandatory | Sample chemical formula |
SampleNumberDensity | Input | number | 0.1 | Sample number density |
SampleInnerRadius | Input | number | 0.05 | Sample inner radius |
SampleOuterRadius | Input | number | 0.1 | Sample outer radius |
CanWorkspace | Input | MatrixWorkspace | Name for the input Can workspace. | |
CanChemicalFormula | Input | string | Can chemical formula | |
CanNumberDensity | Input | number | 0.1 | Can number density |
CanOuterRadius | Input | number | 0.15 | Can outer radius |
BeamHeight | Input | number | 3 | Beam height |
BeamWidth | Input | number | 2 | Beam width |
StepSize | Input | number | 0.002 | Step size |
Interpolate | Input | boolean | True | Interpolate the correction workspaces to match the sample workspace |
NumberWavelengths | Input | number | 10 | Number of wavelengths for calculation |
Emode | Input | string | Elastic | Emode: Elastic or Indirect. Allowed values: [‘Elastic’, ‘Indirect’] |
Efixed | Input | number | 1 | Analyser energy |
OutputWorkspace | Output | WorkspaceGroup | Mandatory | The output corrections workspace group |
Calculates absorption corrections for a cylindrical or annular sample giving output in the Paalman & Pings absorption factors: (correction factor for scattering and absorption in sample), (scattering in sample and absorption in sample and container), (scattering in container and absorption in sample and container) and (scattering and absorption in container).
The input workspace must have a fully defined instrument that has X axis units of wavelength.
Example:
# Create a sample workspace
sample = CreateSampleWorkspace(NumBanks=1, BankPixelWidth=1,
XUnit='Wavelength',
XMin=6.8, XMax=7.9,
BinWidth=0.1)
# Copy and scale it to make a can workspace
can = CloneWorkspace(InputWorkspace=sample)
can = Scale(InputWorkspace=can, Factor=1.2)
# Calculate absorption corrections
corr = CylinderPaalmanPingsCorrection(SampleWorkspace=sample,
SampleChemicalFormula='H2-O',
SampleInnerRadius=0.05,
SampleOuterRadius=0.1,
CanWorkspace=can,
CanChemicalFormula='V',
CanOuterRadius=0.15,
BeamHeight=0.1,
BeamWidth=0.1,
StepSize=0.002,
Emode='Indirect',
Efixed=1.845)
print 'Correction workspaces: %s' % (', '.join(corr.getNames()))
Output:
Correction workspaces: corr_ass, corr_assc, corr_acsc, corr_acc
Categories: Algorithms | Workflow\MIDAS | CorrectionFunctions\AbsorptionCorrections