Path dependent models to predict property changes in graphite irradiated at changing irradiation temperatures

Abstract

Property changes occur in materials subjected to irradiation. The bulk of experimental data and associated empirical models are for isothermal irradiation. The form that these isothermal models take is usually closed form expressions in terms of fluence and irradiation temperature. Irradiation temperature changes do however occur due to operational requirements. Isothermal models are no longer applicable, since experimental observations after an irradiation temperature change demonstrate that properties do not change instantaneously from one isothermal curve to the other. The properties are path-dependent, but the isothermal models are usually point functions.