High Voltage Breakdown of Irradiated Transformer Oil

Transformer oil is the main liquid dielectric for high voltage insulation of equipment used in high energy and nuclear physics. The radiation resistance of transformer oil in these applications is important for lifetime and cost. In this report, breakdown properties of mineral and silicone transformer oils were studied following irradiation from an electron beam, X-rays and photons (gamma). The delivered dose range was (0.01-200) MGy, where CTA film and Alanine dosimeters were used to measure delivered doses. The study of breakdown was conducted for DC and pulsed voltages of both polarities using a Marx generator.