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ConvertToConstantL2 v1¶

../_images/ImageNotFound.png — Enable screenshots using DOCS_SCREENSHOTS in CMake¶

Summary ¶

Used to convert flight paths to have a constant l2 in 2D shaped detectors.

Properties ¶

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	Name of the input workspace
OutputWorkspace	Output	MatrixWorkspace	Mandatory	Name of the output workspace, can be the same as the input

Description ¶

Moves the instrument and then corrects the flight paths such that a flat detector appears spherical with a constant l2 value.

Both time-of-flight sample-detector time and sample to detector distance are corrected to constant values.

The sample to detector distance must be specified as l2 in the instrument parameters file.

So far this has only be tested on the ILL IN5 instrument.

Note ¶

This algorithm is intended for visualisation only. It is not recommended as part of any reduction process.

Example - Add multiple sample logs

# Load an IN5 file
ws = Load('ILL/IN5/104007.nxs')

monitorIndex = ws.getNumberHistograms() - 1  # Monitor is last in the workspace.
print("Before conversion:")
print("Monitor {0} distance from origin: {1:.3f}".format(monitorIndex, ws.getDetector(monitorIndex).getPos().norm()))
for i in range(0, 5):
  print("Detector {0} distance from origin: {1:.3f}".format(i, ws.getDetector(i).getPos().norm()))

# Convert to a detector with constant L2
converted_ws = ConvertToConstantL2(ws)

print("After conversion:")
print("Monitor {0} distance from origin: {1:.3f}".format(monitorIndex, converted_ws.getDetector(monitorIndex).getPos().norm()))
for i in range(0, 5):
  print("Detector {0} distance from origin: {1:.3f}".format(i, converted_ws.getDetector(i).getPos().norm()))

Output:

Before conversion:
Monitor 98304 distance from origin: 0.500
Detector 0 distance from origin: 4.296
Detector 1 distance from origin: 4.291
Detector 2 distance from origin: 4.287
Detector 3 distance from origin: 4.283
Detector 4 distance from origin: 4.278
After conversion:
Monitor 98304 distance from origin: 0.500
Detector 0 distance from origin: 4.000
Detector 1 distance from origin: 4.000
Detector 2 distance from origin: 4.000
Detector 3 distance from origin: 4.000
Detector 4 distance from origin: 4.000

Categories: AlgorithmIndex | Inelastic\Corrections | CorrectionFunctions\InstrumentCorrections