CalculateEfficiency dialog.
Table of Contents
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| InputWorkspace | Input | MatrixWorkspace | Mandatory | The workspace containing the flood data |
| OutputWorkspace | Output | MatrixWorkspace | Mandatory | The name of the workspace to be created as the output of the algorithm |
| MinThreshold | Input | number | 0 | Minimum threshold for a pixel to be considered |
| MaxThreshold | Input | number | 2 | Maximum threshold for a pixel to be considered |
Compute the detector efficiency of SANS data. This algorithm is used by SANS reduction.
The flood is a short for flood field. The flood field is collected from a sample that scatters uniformly in angle to ensure that every pixel on the detector has the potential to see the same number of neutrons. Different materials are currently used at the beamlines to measure the flood field. At present, the standard samples used for measuring the flood field are H2O in a 1 mm path length cell for GP-SANS and Bio-SANS, and a 1 mm sheet of PMMA for EQ-SANS.
The relative detector sensitivity is computed the following way
where 
is the pixel count of the flood data in pixel (x,y).
If a minimum and/or maximum sensitivity is given, the pixels having an
sensitivity outside the given limits are set to -inf (In Mantid EMPTY_DBL).
Note
To run these usage examples please first download the usage data, and add these to your path. In Mantid this is done using Manage User Directories.
Example - Compute the detector efficiency from a BioSANS data file:
# Load your data file
workspace = LoadSpice2D('BioSANS_empty_cell.xml')
# Compute the detector sensitivity
sensitivity = CalculateEfficiency('workspace', MinThreshold=0.5, MaxThreshold=1.5)
Categories: AlgorithmIndex | SANS | CorrectionFunctions\EfficiencyCorrections
C++ header: CalculateEfficiency2.h (last modified: 2020-03-20)
C++ source: CalculateEfficiency2.cpp (last modified: 2020-04-07)