Hello, When neutrons hit materials, it can cause them to degrade and crack. The way this is measured is in displacements per atom. The equation for this effect is the following: Displacements per atom = neutron flux * time * materials cross section (@ that neutron energy) Cracks will form in a normal fission reactor when you reach 1 dpa or higher. As a benchmark, a typical PWR reactor core will experience between 0 and 90 dpa. Here is the question: 1.Does bombarding a material with protons cause cracking or displacements? 2. If yes, then what is the equation used to predict these displacements? 3.Can this equation be used? 4.Is there a similar effect found in: alpha particles, and hydrogen nuclei?