Electrical Characteristics Of Plasma Research Articles

Electron energy probability function measurement in a 2 MHz and 13.56 MHz dual-frequency capacitively coupled argon plasma

The effect of low-frequency power and high-frequency power on the electron energy probability function (EEPF) and the physical and electrical characteristics of plasma are experimentally investigated in a dual-frequency capacitively coupled plasma. RF powers of 2 MHz (low-frequency) and 13.56 MHz (high-frequency) are simultaneously applied to an electrode. EEPFs and DC self-bias voltages (V DC) are measured as one of the two RF powers is increased while the other is fixed. When the 2 MHz power increases at a fixed 13.56 MHz power, the electron density decreases, and the electron temperature increases with the decrease in the population of low-energy (below 5 V) electrons in the EEPF. Note that the increase in the low-frequency power is accompanied by a large decrease in V DC, which is related to the ion energy. On the other hand, when 13.56 MHz power increases at a fixed 2 MHz power, the electron density and the electron temperature significantly increase with the increase in the population of high-energy (above 5 V) electrons in the EEPF, while V DC decreases slightly. Experimental results show that the increase in the low-frequency power enhances the ion energy, and the increase in the high-frequency power enhances electron heating and ionization efficiency.

Electrical Characteristics of Atmospheric Air Corona Plasma by Multi-pin Electrodes

Recently, non-thermal plasma has been widely applied in many fields related to plasma advanced chemical reaction. However, large-scale production of non-thermal plasma is difficult to be achieved in the atmospheric environment. Among other plasma models, corona discharge generated by multi-pin electrodes is one of the good candidates for a massive atmospheric non-thermal plasma production. This paper reports an experimental study on the electrical characteristics of non-thermal atmospheric multi-pin air corona discharges. A plasmamodel composed of multi-pin anodes with 1, 5, 15, and 64 pins, and a planar counter electrodehas been developed. The gap between the electrodes has been 12 mm. Stable streamer glow corona plasma has been generated and observed at the dc-supplied voltage of 14–18 kV. The influences of the electrode number and the supplied voltage on the electrical characteristics of the plasma have been investigated and discussed. The plasma has been found out to be in a self-pulsing discharge mode under every examined experimental condition. The pulsing frequency has increased when the supplied source voltage increased. However, non-periodical pulsing could be observed in the multi-pin electrode cases owing to the multi-discharges from each pin anode. At the same supplied voltage, a greater number of pin electrodes could be sustained with the lower voltage in order to obtain a larger average discharge current. Moreover, more uniform plasma could be achieved, and the transition from glow to arc discharge could be extended due to an interaction of electric field and equipotential lines between the adjacent pin electrodes.