IN-SITU MEASUREMENT OF RADIATION-INDUCED CONDUCTIVITY IN OXIDE INSULATORS DURING NEUTRON-IRRADIATION

An experimental investigation of the in situ electrical conductivity o f Wesgo A1995 polycrystalline alumina at approximately 450 degrees C h as been performed at the high flux beam reactor at Brookhaven National Laboratory. The measured radiation induced conductivity (RIC) was abo ut 10(-8) S/m at an ionizing dose rate of 6000 Gy/s. No evidence for p ermanent radiation induced electrical degradation was observed for an applied electric field of 147 V/mm up to a dose level of approximate t o 1.8 displacements per atom. The effect of neutron irradiation on the electrical properties of two mineral insulated cables was also invest igated. The RIC in the MgO insulation of a coaxial and a triaxial cabl e was measured to be in the range of 6-20 x 10(-8) S/m at an ionizing dose rate of approximate to 6000 Gy/s.