Significance of sample thickness and surface segregation on the electrical conductivity of Wesgo AL995 alumina under ITER environments

The electrical conductivity of 158, 295 and 610μmthick Wesgo AL995 alumina was measured under 1 MeV electron irradiation with an electric field of 300 kV/m at temperatures up to 723 K. A significant increase in the conductivity with increasing the sample thickness is confirmed, but no substantial bulk degradation is found under irradiation up to a dose of 7.0×1022e/m2(7.97×10−5dpa) at 723 K. However, surface breakdown is found only in 295 and …