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MuscatFunc v1

MuscatFunc dialog.

Summary

Calculates multiple scattering using S(Q,w) from specified functions.

Properties

Name	Direction	Type	Default	Description
Instrument	Input	string	iris	Instrument. Allowed values: [‘irs’, ‘iris’, ‘osi’, ‘osiris’]
Analyser	Input	string	graphite002	Allowed values: [‘graphite002’, ‘graphite004’]
Geom	Input	string	Flat	Allowed values: [‘Flat’, ‘Cyl’]
Dispersion	Input	string	Poly	Allowed values: [‘Poly’, ‘CE’, ‘SS’]
SamNumber	Input	string	Mandatory	Sample data run number
NR1	Input	number	1000	MonteCarlo neutrons NR1. Default=1000
NR2	Input	number	1000	MonteCarlo neutrons NR2. Default=1000
Nms	Input	number	1	Number of scatterings. Default=1
DetAngle	Input	number	90	Detector angle. Default=90.0
NQ	Input	number	10	Q-w grid: number of Q values. Default=10
dQ	Input	number	0.2	Q-w grid: Q increment. Default=0.2
NW	Input	number	100	Q-w grid: number of w values. Default=100
dW	Input	number	2	Q-w grid: w increment (microeV). Default=2.0
Coeff1	Input	number	0	Coefficient 1. Default=0.0
Coeff2	Input	number	0	Coefficient 2. Default=0.0
Coeff3	Input	number	50	Coefficient 3. Default=50.0
Coeff4	Input	number	0	Coefficient 4. Default=0.0
Coeff5	Input	number	0	Coefficient 5. Default=0.0
Thick	Input	string	Mandatory	Sample thickness
Width	Input	string	Mandatory	Sample width
Height	Input	number	3	Sample height. Default=3.0
Density	Input	number	0.1	Sample density. Default=0.1
SigScat	Input	number	5	Scattering cross-section. Default=5.0
SigAbs	Input	number	0.1	Absorption cross-section. Default=0.1
Temperature	Input	number	300	Sample temperature (K). Default=300.0
Plot	Input	string	None	Allowed values: [‘None’, ‘Totals’, ‘Scat1’, ‘All’]
Verbose	Input	boolean	True	Switch Verbose Off/On
Save	Input	boolean	False	Switch Save result to nxs file Off/On

Description

Calculates Multiple Scattering based on the Monte Carlo program MINUS. It calculates \(S(Q,w)\) from specified functions (such as those used in JumpFit) and supports both Flat and Cylindrical geometries. More information on the multiple scattering can be procedure can be found in the modes manual.

References

1. M W Johnson, AERE Report R7682 (1974)

Usage

Example - a basic example using MuscatFunc.

def createSampleWorkspace(name, random=False):
        """ Creates a sample workspace with a single lorentzian that looks like IRIS data"""
        import os
        function = "name=Lorentzian,Amplitude=8,PeakCentre=5,FWHM=0.7"
        ws = CreateSampleWorkspace("Histogram", Function="User Defined", UserDefinedFunction=function, XUnit="DeltaE", Random=True, XMin=0, XMax=10, BinWidth=0.01)
        ws = CropWorkspace(ws, StartWorkspaceIndex=0, EndWorkspaceIndex=9)
        ws = ScaleX(ws, -5, "Add")
        ws = ScaleX(ws, 0.1, "Multiply")

        #load instrument and instrument parameters
        LoadInstrument(ws, InstrumentName='IRIS', RewriteSpectraMap=True)
        path = os.path.join(config['instrumentDefinition.directory'], 'IRIS_graphite_002_Parameters.xml')
        LoadParameterFile(ws, Filename=path)
        ws = RenameWorkspace(ws, OutputWorkspace=name)
        return ws


ws = createSampleWorkspace("irs26173_graphite002_red", random=True)
SaveNexus(ws, "irs26173_graphite002_red.nxs")

MuscatFunc(SamNumber='26173', Thick='0.5', Width='0.5', Instrument='irs')

Categories: AlgorithmIndex | Workflow\MIDAS

Source

Python: MuscatFunc.py