Dielectric characteristics on insulation oil due to the aging by electron beam irradiation

The electron beam is used to change a nature of polymers in these days. When the transformer oils is irradiated with electron beam in order to investigate the dielectric characteristics, there is a morphological change. It has already confirmed that the high dose of electron beam is caused to increase the magnitude of dielectric dissipation factor, tanδ, which can be estimated to the insulation of specimen. So, in this experiment, a low dose of electron beam such as 0.5[Mrad], 1[Mrad], 2[Mrad] is irradiated. Tanδ is measured by Video Bridge 2150 in the applying voltage range 300[mV]~1500[mV], in the temperature range 20[°C]~120[°C], and in the frequency range 30[Hz]~1×10⁵[Hz]. In addition to investigating the electrical properties of each specimen, the physical properties of each specimen is analyzed by using the FT-IR spectrum and the ¹H-NMR spectrum