3.5

EQSANSLoad v1

../_images/EQSANSLoad-v1_dlg.png

EQSANSLoad dialog.

Table of Contents

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
LoadMonitors Input boolean True If true, the monitor workspace will be loaded
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: Algorithms | Workflow | SANS

Source

C++ source: EQSANSLoad.cpp

C++ header: EQSANSLoad.h