MultipleScatteringCylinderAbsorption v1¶

MultipleScatteringCylinderAbsorption dialog.

Table of Contents

Summary
Properties
Description
Usage
References
Source

Summary ¶

Multiple scattering absorption correction, originally used to correct vanadium spectrum at IPNS.

Properties ¶

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	The name of the input workspace.
OutputWorkspace	Output	MatrixWorkspace	Mandatory	The name of the output workspace.
AttenuationXSection	Input	number	2.8	Coefficient 1, absorption cross section / 1.81 if not set with SetSampleMaterial
ScatteringXSection	Input	number	5.1	Coefficient 3, total scattering cross section if not set with SetSampleMaterial
SampleNumberDensity	Input	number	0.0721	Coefficient 2, density if not set with SetSampleMaterial
CylinderSampleRadius	Input	number	0.3175	Sample radius, in cm

This algorithm is a port to C++ of a multiple scattering absorption correction, used to correct the vanadium spectrum for the GPPD instrument at the IPNS. The correction calculation was originally worked out by Jack Carpenter and Asfia Huq and implemented in Java by Alok Chatterjee. The java code was translated to C++ in Mantid by Dennis Mikkelson.

Usage ¶

Example: A simple cylindrical sample

ws = CreateSampleWorkspace("Histogram",NumBanks=1,BankPixelWidth=1)
ws = ConvertUnits(ws,"Wavelength")
ws = Rebin(ws,Params=[1])
SetSampleMaterial(ws,ChemicalFormula="V")

#restrict the number of wavelength points to speed up the example
wsOut = MultipleScatteringCylinderAbsorption(ws,CylinderSampleRadius=0.2)

print "Output: ", wsOut.readY(0)

Output:

Output:  [  5.90548152   5.90559329  16.28933615   5.90581685   5.90592863
   1.62244888]

References ¶

The source for how this calculation is done is

J.M. Carpenter Attenuation Correction Factor for Scattering from Cylindrical Targets Review of Scientific Instruments 40.4 (1969): 555. doi: 10.1063/1.1684003
D.F.R. Mildner, J.M. Carpenter, and C.A. Pelizzari Generalized Attenuation Correction Factor for Scattering from Cylindrical Targets Review of Scientific Instruments 45.4 (1974): 572. doi: 10.1063/1.1686687
D.F.R. Mildner and J.M.Carpenter Improvements to the Chebyshev Expansion of Attenuation Correction Factors for Cylindrical Samples. J Appl Crystallogr 23.5 (1990): 378–386 doi: 10.1107/S0021889890005258