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EstimateDivergence v1

../_images/EstimateDivergence-v1_dlg.png

EstimateDivergence dialog.

Summary

Estimate the divergence of each detector pixel

See Also

EstimateResolutionDiffraction

Properties

Name

Direction

Type

Default

Description

InputWorkspace

Input

MatrixWorkspace

Mandatory

Workspace to have divergence calculated from

alpha

Input

number

0

Vertical divergence parameter

beta0

Input

number

0

Horizontal divergence parameter

beta1

Input

number

0

Other horizontal divergence parameter

OutputWorkspace

Output

MatrixWorkspace

Mandatory

Workspace containing the divergence of each detector/spectrum

Description

This algorithm estimates the divergence of a diffraction instrument using equation 6.9 of Windsor

\[\Delta\theta_{div} = \frac{1}{2} \sqrt{\Delta(2\theta)^2 + \alpha_0 + \frac{4\left(\beta_0^2 + \beta_1^2\right)}{\sin^2(2\theta)}}\]

Where \(\Delta\theta_{div}\) is the divergence, \(\Delta(2\theta)\) is the angular uncertainty due to the detector size, \(\alpha_0\) is the uncertainty in the incident collimation in the scattering plane, and the \(\beta\) terms are the angular uncertainties out of the scattering plane for the incident and scattered beam.

The results of this calculation can be supplied as an optional workspace to EstimateResolutionDiffraction.

Usage

Example - EstimateDivergence

LoadEmptyInstrument(Filename='POWGEN_Definition_2017-05-01.xml', OutputWorkspace='PG3')
ws = EstimateDivergence(InputWorkspace='PG3')

# Print the result
print("The output workspace has {} spectra".format(ws.getNumberHistograms()))

Output:

The output workspace has 43121 spectra

References

  1. Windsor, C. G. Pulsed Neutron Scattering. London: Taylor & Francis, 1981. Print. ISBN-10: 0470271310, ISBN-13: 978-0470271315

See also

Algorithm EstimateResolutionDiffraction v1

Categories: AlgorithmIndex | Diffraction\Utility

Source

C++ header: EstimateDivergence.h

C++ source: EstimateDivergence.cpp