DDCS: Understanding What it Measures

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Hello all,

I was doing some reading on doubly differential cross-sections and was wondering what does this actually measure, in a physical sense. The way I see it, it looks like the differentiation of the incident angle of the scattering with respect to the reflected angle? Also, there's also a second differentiation with respect to the energy. I'm assuming that is to show the energy lost when an electron is scattered? I'm not really sure what is going on at all with this concept. Any help is appreciated. Thank you.
 
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The doubly differential cross-section (DDCS) measures the probability of an incident particle (e.g. electron) being scattered at a given angle and energy. It is usually used for studying interactions between particles and atoms, molecules or clusters. The DDCS is expressed as a function of the scattering angle, energy and polarization of the incident particle. It is a measure of the probability per unit solid angle of the scattering of an incident particle into a given direction at a given energy. It can also be used to study the scattering of light by particles.
 
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