3.6

MuscatFunc v1

../_images/MuscatFunc-v1_dlg.png

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: Algorithms | Workflow\MIDAS