IN-BEAM DIELECTRIC-PROPERTIES OF ALUMINA

The dielectric properties (permittivity and loss tangent) of a 99.7% p urity alumina grade have been measured over a wide frequency range (1 kHz-15 GHz) before and after 2 MeV electron irradiation at different t emperatures. The dielectric properties at 15 GHz were measured during irradiation. Both prompt and fluence effects are observed together wit h permanent changes which continue to evolve following irradiation. Th e behaviour is complex, consistent with both radiation induced electro nic effects and aggregation processes.