Characterization of the Electroluminescence of Oil Produced by an Electric Discharge

Abstract

The spectroscopic analysis of low-current electrical discharges (approximately 0.1 mA) in liquid I-40A oil was carried out. The discharge spectrum is similar to that for photoluminescence and hydrodynamic luminescence and is determined mainly by the highlighting individual luminescent centers. There are components in the emission spectrum corresponding to the radiation of atoms of the electrode material, as well as a split Hα hydrogen line. From the analysis of the emission spectrum, the electric field strength was approximately 60 kV/cm and the concentration of electrons ∼1014 cm−3. There were no components corresponding to molecular radiation in the spectrum. It has been hypothesized that the discharge in a liquid occurs when the steam phase forms in the electric field. However, these results raise questions about the composition of this steam phase. Although similar emissions for I-40A oil were produced by electrical discharges and as photo- or hydroluminescence, ultrasonic sonoluminescence has never been observed for I-40A oil. Thus, there is no way to excite the environment with ultrasound, unlike for other forms of luminescence, such as by an electrical discharge.