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GaussianComptonProfile

Description

The GaussianComptonProfile function describes the Compton profile of a nucleus using a Gaussian approximation convoluted with an instrument resolution function, that is approximated by a Voigt function. The function approximates the Count rate, \(C(t)\) as [1],

\[C(t) = \left[\frac{E_0I(E_0)}{q}\right](t) A_m J_M(y_M)\otimes R_M(t) \label{a}\]

for the given mass, M, \(J_M\) is approximated using a Gaussian and \(R_M\) is the resolution function. In Equation \(\ref{a}\), the term \(A_M\) is proportional to the scattering intensity and \(\left[\frac{E_0I(E_0)}{q}\right](t)\) depends on the incident neutron spectrum, which are both obtained the input workspace to the fit.

The Gaussian approximation, \(J_M\), takes two input parameters,

• Width: \(\sigma\)

• Intensity: \(I\)

The instrument resolution, \(R_M\), is approximated by a Voigt function using the VesuvioResolution function.

Properties (fitting parameters)

Name	Default	Description
Mass	0.0	Atomic mass (amu)
Width	1.0	Gaussian width parameter
Intensity	1.0	Gaussian intensity parameter

References

[1] Mayers J, Abdul-Redah T. The measurement of anomalous neutron inelastic cross-sections at electronvolt energy transfers. J Phys: Condens Matter 2004;16:4811–32. https://doi.org/10.1088/0953-8984/16/28/005

Categories: FitFunctions | General

Source

C++ header: GaussianComptonProfile.h

C++ source: GaussianComptonProfile.cpp