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ElasticDiffSphere¶

Description¶

This fitting function models the elastic part of the dynamics structure factor of a particle undergoing continuous diffusion but confined to a spherical volume, ElasticDiffSphere.

\[S(Q,E\equiv \hbar \omega) = (3 \frac{j_1(QR)}{QR})^2(Q\cdot R) \delta (\omega)\]

Because of the spherical symmetry of the problem, the structure factor is expressed in terms of the \(j_l(z)\) spherical Bessel functions.

Attributes (non-fitting parameters)¶

Name	Type	Default	Description
Q
WorkspaceIndex

\(Q\) (double, default=1.0) Momentum transfer

Properties (fitting parameters)¶

Name	Default	Description
Height	1.0	Scaling factor to be applied to the resolution.
Centre	0.0	Shift along the x-axis to be applied to the resolution.
Radius	2.0	Sphere radius

Categories: FitFunctions | QuasiElastic

Source¶

C++ header: ElasticDiffSphere.h (last modified: 2020-03-20)

C++ source: ElasticDiffSphere.cpp (last modified: 2020-03-20)