\(\renewcommand\AA{\unicode{x212B}}\)

EQSANSLoad v1

Enable screenshots using DOCS_SCREENSHOTS in CMake

Summary

Load EQSANS data.

Properties

Name	Direction	Type	Default	Description
Filename	Input	string		The name of the input event Nexus file to load. Allowed extensions: [‘_event.nxs’]
InputWorkspace	Input	EventWorkspace		Input event workspace. Assumed to be unmodified events straight from LoadEventNexus
OutputWorkspace	Output	MatrixWorkspace	Mandatory	Then name of the output EventWorkspace
NoBeamCenter	Input	boolean	False	If true, the detector will not be moved according to the beam center
UseConfigBeam	Input	boolean	False	If true, the beam center defined in the configuration file will be used
BeamCenterX	Input	number	Optional	Beam position in X pixel coordinates (used only if UseConfigBeam is false)
BeamCenterY	Input	number	Optional	Beam position in Y pixel coordinates (used only if UseConfigBeam is false)
UseConfigTOFCuts	Input	boolean	False	If true, the edges of the TOF distribution will be cut according to the configuration file
LowTOFCut	Input	number	0	TOF value below which events will not be loaded into the workspace at load-time
HighTOFCut	Input	number	0	TOF value above which events will not be loaded into the workspace at load-time
SkipTOFCorrection	Input	boolean	False	IF true, the EQSANS TOF correction will be skipped
WavelengthStep	Input	number	0.1	Wavelength steps to be used when rebinning the data before performing the reduction
UseConfigMask	Input	boolean	False	If true, the masking information found in the configuration file will be used
UseConfig	Input	boolean	True	If true, the best configuration file found will be used
CorrectForFlightPath	Input	boolean	False	If true, the TOF will be modified for the true flight path from the sample to the detector pixel
PreserveEvents	Input	boolean	True	If true, the output workspace will be an event workspace
SampleDetectorDistance	Input	number	Optional	Sample to detector distance to use (overrides meta data), in mm
SampleDetectorDistanceOffset	Input	number	Optional	Offset to the sample to detector distance (use only when using the distance found in the meta data), in mm
SampleOffset	Input	number	Optional	Offset to be applied to the sample position (use only when using the detector distance found in the meta data), in mm
DetectorOffset	Input	number	Optional	Offset to be applied to the detector position (use only when using the distance found in the meta data), in mm
LoadMonitors	Input	boolean	True	If true, the monitor workspace will be loaded
LoadNexusInstrumentXML	Input	boolean	True	Reads the embedded Instrument XML from the NeXus file (optional, default True).
OutputMessage	Output	string
ReductionProperties	Input	string	__sans_reduction_properties

Description

Workflow algorithm that loads EQSANS event data and applies basic corrections to the workspace. The workflow proceeds as follows:

1. Determine the sample-detector distance and store it in the logs.

2. Locate the appropriate instrument configuration file and process it according to the input properties.

3. Move the detector position to the correct sample-detector distance.

4. Determine the source slit size and store it in the logs.

5. Read in the masked areas of the detector from the instrument configuration file and store them in the logs so that we can retrieve them later (see SANSMask).

6. Move the detector according to the correct beam center position, which is either given as input to the algorithm or pre-determined and stored in the input ReductionProperties.

7. Apply a TOF correction to take into account frame correction and the neutron flight path using EQSANSTofStructure. This step includes trimming the edges of the TOF distribution according to the input properties or the instrument configuration file.

8. Convert TOF into wavelength.

9. Rebin the data according to the input WavelengthStep.

This algorithm is rarely called directly. It is called by SANSReduction.

Categories: AlgorithmIndex | Workflow\SANS

Source

C++ header: EQSANSLoad.h

C++ source: EQSANSLoad.cpp