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.