Inertia effect on thermal shock by laser beam shot

A stress wave generates and propagates in a beam window, a target container and solid target plates of the target system for neutron spallation source because of a thermal shock induced by an injection of a high-intensity proton beam. In this study, a thermal shock experiment was carried out using a ruby laser to investigate the behavior of the stress wave propagation. Numerical analyses on the stress waves induced by the thermal shock were carried out. It was confirmed that tensile stress waves were generated at the border of the heated area because of the inertia effect of the propagation of compressive stresses to outside of the heated area associated with the thermal shock. Subsequently the tensile stress waves concentrate at the center of the non-heated surface to become large. These trends are adequately supported by the numerical results.