1.7.10. guinier¶
Parameter | Description | Units | Default value |
---|---|---|---|
scale | Source intensity | None | 1 |
background | Source background | cm-1 | 0.001 |
rg | Radius of Gyration | Å | 60 |
The returned value is scaled to units of cm-1 sr-1, absolute scale.
Definition
This model fits the Guinier function
to the data directly without any need for linearisation (cf. the usual plot of \(\ln I(q)\) vs \(q^2\)). Note that you may have to restrict the data range to include small q only, where the Guinier approximation actually applies. See also the guinier_porod model.
For 2D data the scattering intensity is calculated in the same way as 1D, where the \(q\) vector is defined as

Fig. 1.101 Figure 1: 1D plot corresponding to the default parameters of the model.
References
A Guinier and G Fournet, Small-Angle Scattering of X-Rays, John Wiley & Sons, New York (1955)