Debye-Waller factor

[KyleQianliMa]

Description of work

EWM 9033

DebyeWallerFactorCorrectionMD applies debye-waller factor correction to extract S(q, \omega) from scattering signal. It scales the signal by the inverse of debye-waller factor exp(^2 * <u^2>/3) assuming isotropic hamonic potnetial.

Summary of work

Further detail of work

To test:

Creating a fake MDevent works space and bin the intensity uniformly for 1000 counts between 1-4.
Observe the plotted data and see it was indeed scaled by an expotential function. Note the form should follow exp(x) not exp(-x) because we are scaling the intensity to remove debye-waller factor.

# Create a test MD workspace
ws = CreateMDWorkspace(Dimensions='1', Extents='1,4',
                     Names='|Q|', Units='A')
FakeMDEventData(ws, UniformParams=-6000)

# Run the algorithm
wsOut = DebyeWallerFactorCorrectionMD(ws, MeanSquaredDisplacement=0.15)

# Bin the result so that it can be printed
wsOut = BinMD(wsOut, AlignedDim0='|Q|,1,4,6')
ws = BinMD(ws, AlignedDim0='|Q|,1,4,6')

plt.plot([int(x) for x in ws.getSignalArray()])
plt.plot([int(x) for x in wsOut.getSignalArray()])
plt.show()

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[sf1919]

This will also require a release note.

[KyleQianliMa]

Will update once the PR is ready

[sf1919]

Apologies - I thought it was ready as it was not a draft PR.