6.4

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MDNormSCDPreprocessIncoherent v1

../_images/MDNormSCDPreprocessIncoherent-v1_dlg.png

MDNormSCDPreprocessIncoherent dialog.

Summary

Creates the Solid Angle and Flux workspace from an incoherent scatterer for MDNormSCD

Properties

Name Direction Type Default Description
Filename Input list of str lists Mandatory Files to combine in reduction. Allowed extensions: [‘_event.nxs’, ‘.nxs.h5’, ‘.nxs’]
Background Input string   Background run. Allowed extensions: [‘_event.nxs’, ‘.nxs.h5’, ‘.nxs’]
BackgroundScale Input number 1 The background will be scaled by this number before being subtracted.
FilterByTofMin Input number Optional Optional: To exclude events that do not fall within a range of times-of-flight. This is the minimum accepted value in microseconds. Keep blank to load all events.
FilterByTofMax Input number Optional Optional: To exclude events that do not fall within a range of times-of-flight. This is the maximum accepted value in microseconds. Keep blank to load all events.
MomentumMin Input number Mandatory Minimum value in momentum.
MomentumMax Input number Mandatory Maximum value in momentum.
GroupingFile Input string   A file that consists of lists of spectra numbers to group. See GroupDetectors. Allowed extensions: [‘.xml’, ‘.map’]
NormaliseByCurrent Input boolean True Normalise the Solid Angle workspace by the proton charge.
LoadInstrument Input string   Load a different instrument IDF onto the data from a file. See LoadInstrument. Allowed extensions: [‘.xml’]
DetCal Input string   Load an ISAW DetCal calibration onto the data from a file. See LoadIsawDetCal. Allowed extensions: [‘.detcal’]
MaskFile Input string   Masking file for masking. Supported file format is XML and ISIS ASCII. See LoadMask. Allowed extensions: [‘.xml’, ‘.msk’]
SphericalAbsorptionCorrection Input boolean False Apply Spherical Absorption correction using AnvredCorrection
LinearScatteringCoef Input number Optional Linear scattering coefficient in 1/cm. If not provided this will be calculated from the material cross-section if present (set with SetSampleMaterial)
LinearAbsorptionCoef Input number Optional Linear absorption coefficient at 1.8 Angstroms in 1/cm. If not provided this will be calculated from the material cross-section if present (set with SetSampleMaterial)
Radius Input number Optional Radius of the sample in centimeters. f not provided the radius will be taken from the sample shape if it is a sphere (set with SetSample).
SolidAngleOutputWorkspace Output Workspace Mandatory Output Workspace for Solid Angle
FluxOutputWorkspace Output Workspace Mandatory Output Workspace for Flux

Description

This algorithm preprocesses an incoherent scattering sample (usually Vanadium) for use with MDNormSCD. The input filename follows the syntax from MultipleFileProperty. The resulting workspaces can be saved with SaveNexus.

Usage

Corelli example using multiple files with masking

# Create a simple mask file
MaskFilename=mantid.config.getString("defaultsave.directory")+"MDNormSCDPreprocessIncoherent_mask.xml"
LoadEmptyInstrument(InstrumentName='CORELLI', OutputWorkspace='CORELLI')
# Missing banks
MaskBTP('CORELLI', Bank='1-6,29,30,62,63-68,91')
# End of tubes
MaskBTP('CORELLI', Pixel='1-15,242-256')
SaveMask('CORELLI', MaskFilename)

SA, Flux = MDNormSCDPreprocessIncoherent(Filename='CORELLI_28119-28123',
                                         MomentumMin=2.5,
                                         MomentumMax=10,
                                         MaskFile=MaskFilename)

Solid Angle instrument view:

../_images/MDNormSCDPreprocessIncoherent_SA.png

Flux spectrum plot:

../_images/MDNormSCDPreprocessIncoherent_Flux.png

TOPAZ example with backgound subtraction, grouping, masking and Spherical Absorption Correction

SA, Flux = MDNormSCDPreprocessIncoherent(Filename='TOPAZ_15670',
                                         Background='TOPAZ_15671',
                                         FilterByTofMin=500,
                                         FilterByTofMax=16000,
                                         MomentumMin=1.8,
                                         MomentumMax=12.5,
                                         GroupingFile='/SNS/TOPAZ/IPTS-15376/shared/calibration/TOPAZ_grouping_2016A.xml',
                                         DetCal='/SNS/TOPAZ/IPTS-15376/shared/calibration/TOPAZ_2016A.DetCal',
                                         MaskFile='/SNS/TOPAZ/IPTS-15376/shared/calibration/TOPAZ_masking_2016A.xml',
                                         SphericalAbsorptionCorrection=True,
                                         LinearScatteringCoef=0.367,
                                         LinearAbsorptionCoef=0.366,
                                         Radius=0.2)
print(SA.getNumberHistograms())
print(SA.blocksize())
print(Flux.getNumberHistograms())
print(Flux.blocksize())

Output:

1507328
1
23
10000