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

EQSANSLoad v1

../_images/ImageNotFound.png

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.

LoadEQSANS.png

Categories: AlgorithmIndex | Workflow\SANS

Source

C++ header: EQSANSLoad.h

C++ source: EQSANSLoad.cpp