Photodisintegration is a physical process in which extremely high energy gamma rays interact with an atomic nucleus and cause it to enter an excited state, which immediately decays into two or more daughter nuclei. A simple example is when a single proton or neutron is effectively knocked out of the nucleus by the incoming gamma ray, and an extreme example is when the gamma ray induces a spontaneous nuclear fission reaction. This process is essentially the reverse of nuclear fusion, where lighte… (More on Photodisintegration)