3.12

ConvertToConstantL2 v1

../_images/ConvertToConstantL2-v1_dlg.png

ConvertToConstantL2 dialog.

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: Algorithms | Inelastic\Corrections | CorrectionFunctions\InstrumentCorrections

Source

C++ source: ConvertToConstantL2.cpp (last modified: 2017-08-01)

C++ header: ConvertToConstantL2.h (last modified: 2016-11-02)