[en] Load relaxation experiments were performed on five rocksalt type ionic crystals: potassium iodide, lithium fluoride, sodium fluoride, sodium chloride, and silver chloride. A mathematical analysis verified the existence of stress, strain rate, and temperature used. Special attention was drawn to the role of impurities and radiation-induced point defects on the plastic flow of ionic crystals. The mathematical analysis showed that point defects induced by gamma radiation enhance the high temperature component of flow stress