porod
Porod function
Parameter |
Description |
Units |
Default value |
---|---|---|---|
scale |
Source intensity |
None |
1 |
background |
Source background |
cm-1 |
0.001 |
The returned value is scaled to units of cm-1 sr-1, absolute scale.
This model fits the Porod function
to the data directly without any need for linearisation (cf. Log I(q) vs Log q).
Here \(C = 2\pi (\Delta\rho)^2 S_v\) is the scale factor where \(S_v\) is the specific surface area (ie, surface area / volume) of the sample, and \(\Delta\rho\) is the contrast factor.
For 2D data: The 2D scattering intensity is calculated in the same way as 1D, where the q vector is defined as

Fig. 113 1D plot corresponding to the default parameters of the model.
Source
porod.py
References
- 1
G Porod. Kolloid Zeit. 124 (1951) 83
- 2
L A Feigin, D I Svergun, G W Taylor. Structure Analysis by Small-Angle X-ray and Neutron Scattering. Springer. (1987)
Authorship and Verification
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