FlatPlatePaalmanPingsCorrection dialog.
Table of Contents
| 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 in atoms/Angstrom3 |
| SampleThickness | Input | number | 0 | Sample thickness in cm |
| SampleAngle | Input | number | 0 | Sample angle in degrees |
| CanWorkspace | Input | MatrixWorkspace | Name for the input container workspace | |
| CanChemicalFormula | Input | string | Container chemical formula | |
| CanNumberDensity | Input | number | 0.1 | Container number density in atoms/Angstrom3 |
| CanFrontThickness | Input | number | 0 | Container front thickness in cm |
| CanBackThickness | Input | number | 0 | Container back thickness in cm |
| NumberWavelengths | Input | number | 10 | Number of wavelengths for calculation |
| Interpolate | Input | boolean | True | Interpolate the correction workspaces to match the sample workspace |
| 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 flat plate 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).
Details of the analytical method used to calculate the correction factors is available in RAL Technical Report 74-103.
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 = FlatPlatePaalmanPingsCorrection(SampleWorkspace=sample,
SampleChemicalFormula='H2-O',
SampleThickness=0.1,
SampleAngle=45,
CanWorkspace=can,
CanChemicalFormula='V',
CanFrontThickness=0.01,
CanBackThickness=0.01,
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 | PythonAlgorithms | CorrectionFunctions | AbsorptionCorrections