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EstimateDivergence v1

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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