AnnularRingAbsorption v1#

Summary#

Calculates bin-by-bin correction factors for attenuation due to absorption in a cylindrical sample in the wall of a hollow can

Properties#

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	The input workspace in units of wavelength.
OutputWorkspace	Output	MatrixWorkspace	Mandatory	The name to use for the output workspace.
CanOuterRadius	Input	number	Mandatory	The outer radius of the can in centimetres
CanInnerRadius	Input	number	Mandatory	The inner radius of the can in centimetres
SampleHeight	Input	number	Mandatory	The height of the sample in centimetres
SampleThickness	Input	number	Mandatory	The thickness of the sample in centimetres
SampleChemicalFormula	Input	string	Mandatory	Chemical composition of the sample material
SampleNumberDensity	Input	number	Mandatory	The number density of the sample in number of formulas per cubic angstrom
NumberOfWavelengthPoints	Input	number	Optional	The number of wavelength points for which a simulation is atttempted (default: all points)
EventsPerPoint	Input	number	300	The number of “neutron” events to generate per simulated point
SeedValue	Input	number	123456789	Seed the random number generator with this value

Description#

Sets up a hollow sample shape, along with the required material properties, and runs the MonteCarloAbsorption algorithm. This algorithm merely serves as a simpler interface to define the shape & material of the sample without having to resort to the more complex CreateSampleShape & SetSampleMaterial algorithms. The computational part is all taken care of by MonteCarloAbsorption. Please see that documentation for more details.

Assumptions#

The algorithm currently assumes that the can wall is sufficiently thin & a weak absorber so that it can be ignored.

Usage#

Example

sample_ws = CreateSampleWorkspace("Histogram",NumBanks=1) # fake some data in TOF
sample_ws = ConvertUnits(sample_ws, Target="Wavelength")
factors = \
  AnnularRingAbsorption(sample_ws,
    SampleHeight=3.8, SampleThickness=0.05, CanOuterRadius=1.1,CanInnerRadius=0.92,
    SampleChemicalFormula="Li2-Ir-O3",SampleNumberDensity=0.004813,
    EventsPerPoint=300)

print("The created workspace has one entry for each spectra: {}".format(factors.getNumberHistograms()))
print("Just divide your data by the correction to correct for absorption.")

Output:

The created workspace has one entry for each spectra: 100
Just divide your data by the correction to correct for absorption.

Categories: AlgorithmIndex | CorrectionFunctions\AbsorptionCorrections

Source#

C++ header: AnnularRingAbsorption.h

C++ source: AnnularRingAbsorption.cpp