CHARACTERISTICS OF HIGH CURRENT NANOSECOND DISCHARGE
IN AIR WITH ELECTROLYTIC ELECTRODE
1Shuaibov A., 2Chyhin V.
1Uzhgorod National University, Ukraine
2LF National Academy, Lviv, Ukraine
The pulse high-current discharges with duration of 5-150 nanoseconds in the air above the surface of liquid are employed to produce hydroxyl radicals, ozone and UV radiation, which are then used for water treatment, air sterilization, as well as for initiation of reactions of metal oxide nanostructures synthesis, particularly a colloidal solution based on zinc nanoparticles [1].[2] provides the results of research of the water purification from phenol and heptane contaminants in the similar type of discharge with the voltage and current pulse duration of 150 ns and the current pulseamplitude of 100 - 170 A.
This paper presents the results of investigations of the space, electrical and optical characteristics of the pulsed periodic high-current nanosecond discharge in the system of "blade - surface of copper sulphate solution in the distilled water" electrodes. The discharge with the distance between electrodes of 3-12 mm was ignited in air at atmospheric pressure and at the voltage pulse repetition rate of 35-100 Hz. The equipment and experimental conditions are described more detail in [1].
In experiments the colloidal solution of the greencopper nanoparticles was obtained.It was transformed from the solution of blue colorcopper sulphate after a few hours of treatment in the investigateddischarge. The color of discharge was determined by the optical characteristics of the plasmon resonance of copper oxide nanoparticles, and it was coincided with the color of colloidal solution of copper oxide nanoparticles, which were obtained in a laser plasma in distilled water.
The discharge area consists of 15 relatively homogeneous plasma sheets, which were related to the surface of the electrolyte and covered an area of 40×25 mm2. With increasing of voltage pulse repetition frequency from 35 Hz to 100 Hz, the uniformity and intensity of the discharge radiation were increased.
In the spectrum of this dischargeplasma radiation the predominantly bands of the second positive system of nitrogen molecule N2, which is the main component of air,were registered .
Thus, the investigation of the nanosecond atmospheric pressure discharge characteristics showed that under the conditions of this experiment the homogeneous plasma sheets are formed. They cover the water area of 40×25 mm2.
The maximum discharge pulse power in a pack of the high-frequency pulses of positive polarity reached 1.8 MW at the full power of pulse train of 30 mJ. The discharge can be used as a pulsed plasma chemical reactor for the synthesis of colloidal solutions based on metal oxide nanostructures.
[1] Shuaibov A.K. , SheveraI.V., Kozak Ya.Yu., Kentesh H.V.// ZhTF. 2014. V.84, p.143.
[2] Belinsky V.V., Bozhko I.V., Charny D.V.// Technical electrodynamics 2010. № 3. P. 21.
Fig.1. The structure of discharge cell: 1 – cuvette, 2 - screws for installation of interelectrode distance, 3 - mounting of electrode, 4 - blade system, 5 - metal electrode dipped in water, 6 - distilled water, 7 - quartz window, 8 - metal screen.
Fig.2. The structure of discharge cell with rotary electrodes: 1 - cuvette made of organic glass, 2 - regulating electrodescrews, 3 – blades, 4 - distilled water or control salt solution of zinc chloride (ZnCl2) in water.
A).
B).
Figure 3. Photos of the nanosecond discharge with the electrode based on distilled water (view from the end of A and side B) at the variousvoltagerepetition frequencies at the distance between edges of blades and watersurface of 7,5 mm and the thickness of water over the solid metal electrode of 4 mm.
Figure 4. View of the nanosecond discharge in the "blade-blade"electrode system which is set above the distilled water and control salt solution of zinc chloride in water
Figure 5. Temporal dependences of the voltage, current and power of the nanosecond discharge (discharge over the surface of distilled water) at the distance between electrodes of 25 mm.