The effect of the exposure to different irradiation sources on the thermal conductivity of Al2O3

The high temperature thermal conductivity of Al2O3 exposed to the radiation of four different sources (neutron and α-particles) is measured by a laser flash technique. In addition, annealing experiments are performed in the temperature range from 300 to 2000 K in vacuum (10-5 mbar). The reduction of thermal conductivity due to radiation induced defects is not a function of the damage dose alone but depends strongly on irradiation temperature. The number of stable point defects in the irradiated samples is estimated using a microscopic model which describes the reduction of thermal conductivity in terms of point defects and extended (3D) defects introduced by the irradiation process. (orig.)