A neutron is at rest inside a crystalline solid. Can a phonon come along and give up all of its energy to the neutron? Address the question with a graphical solution, i.e. overlay the dispersion curves for neutrons and phonons. For simplicity assume that the solid has a basis of a single atom and have only one acoustic branc In the textbook, it says that a neutron's dispersion curve can only be found through experiment. Because neutron's don't really interact with much, I'm stumped about how to find such a curve in order to overlay the two.