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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
C++ source: ElasticDiffSphere.cpp