SAP - Scattering Angular distribution Plot v 2.1

SAP (Scattering Angular distribution Plot) is a graphical tool developed at the University of Bologna to compute and plot the angular distribution of scattering kernels and of reflected and transmitted scattering intensities, for homogeneous mono-layer materials composed by single elements, compounds and mixture of compounds, with a infinite or a finite thickness (Fernandez et al., 2010a,b).

 For a target of a given substance, density and thickness, struck by a beam with defined energy, intensity and angle of incidence, the code SAP computes and visualizes a polar plot (as a functions of the scattering angle ) of the following quantities:

—      the electronic angular differential cross-section for Rayleigh and Compton scattering (total and for each element of the considered substance);

—      the atomic angular differential cross-section for Rayleigh and Compton scattering (total and for each element of the considered substance);

—      the angular distribution of the form factor for Rayleigh scattering (total and for each element of the considered substance);

—      the angular distribution of the scattering function for Compton scattering (total and for each element of the considered substance);

—      the angular distribution of the reflected and transmitted flux or intensity for Rayleigh and Compton scattering (only total);

—      the angular distribution of the reflected and transmitted Rayleigh to Compton intensity ratio (R/C) (only total)

 Every computation consists of four stages which are interactively activated by the user.

1.     Definition of the required parameters: substance name and composition, monochromatic excitation energy, eventual normalization of the results, data sources used to compute FFs and SFs, intensity of the source, angle of incidence of the source, density and thickness of the target, eventual scale to have a better visualization of reflected and transmitted R/C ratio.

2.     Computation of the mentioned angular distributions with automatic saving of the results in the report file sap_out.txt..

3.     Graphical visualization of the results: polar plots of the interest magnitudes can be selected from a list menu in the plot window. Each plot shows a closed curve corresponding to a plane section of the 3D angular distribution (which may be obtained by rotating this curve around the symmetry axis). To simplify the comparison, the incidence direction coincides always with the symmetry axis of the cross-sections. Each plot shows a graded circle reporting the polar angle. In the plots of the angular differential cross-sections, in case of mixtures or compounds, the same graph shows together the total distribution and the contributions of the single elements. In the plots of flux and intensity, the finite sample (independently of its thickness) is represented as a horizontal line dividing the graph area in two halves: the upper side shows reflection and the lower one shows transmission.

4.     Saving the plot as encapsulated postscript (eps) file.

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ALMA MATER STUDIORUM - Università  di Bologna
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