ABSTRACT To understand the self sustained propagation of the plasma jet/bullet in air under atmos... more ABSTRACT To understand the self sustained propagation of the plasma jet/bullet in air under atmospheric pressure, the ignition of the plasma jet/bullet, the plasma jet/bullet ignition point in the plasma pencil, the formation time and the formation criteria from a dielectric barrier configured plasma pencil were investigated in this study. The results were confirmed by comparing these results with the plasma jet ignition process in the plasma pencil without a dielectric barrier. Electrical, optical, and imaging techniques were used to study the formation of the plasma jet from the ignition of discharge in a double dielectric barrier configured plasma pencil. The investigation results show that the plasma jet forms at the outlet of the plasma pencil as a donut shaped discharge front because of the electric field line along the outlet's surface. It is shown that the required time for the formation of the plasma jet changes with the input voltage of the discharge. The input power calculation for the gap discharge and for the whole system shows that 56% of the average input power is used by the first gap discharge. The estimated electron density inside the gap discharge is in the order of 1011 cm−3. If helium is used as a feeding gas, a minimum 1.48×10−8 C charge is required per pulse in the gap discharge to generate a plasma jet.
2010 Abstracts IEEE International Conference on Plasma Science, 2010
ABSTRACT Recent studies have shown that low temperature atmospheric pressure plasma jets are form... more ABSTRACT Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the propagation of small plasma bullets traveling at very high velocities in ambient air. In this paper we report on the spatial evolution of the plasma jet properties investigated from the jet current density, where the jet current was measured by placing a lab-made probe along the jet propagation axis. The plasma jet was generated by a plasma pencil powered with high voltage short-duration pulses. The average current density, power density, electric field and electron density for every 0.5 cm plasma jet segment along the jet propagation trail were measured. The average peak current density, power density, and the electric field of the plasma jet were respectively 0.64 (A/cm2), 6.6 (kW/cm3) and 11.5 (kV/cm). The drift velocity of the electrons was calculated for the measured electric field along the jet axis and it showed a good agreement with the plasma jet's front velocity measured by ICCD image tracking. It also shows that the helium gas plays an important role in the jet propagation. The estimated average electron density in the plasma jet is 4.8+1011 cm3.
2010 Abstracts IEEE International Conference on Plasma Science, 2010
ABSTRACT Summary form only given. The propagation velocity of the atmospheric helium pulsed plasm... more ABSTRACT Summary form only given. The propagation velocity of the atmospheric helium pulsed plasma jet/bullet generated by the plasma pencil has been investigated through electrical and optical diagnostic techniques. The electrically-based technique measures the jet velocity from the time delay between the jet current peaks along the jet propagation axis. Using optical emission spectroscopy (OES) the temporal evolution of the reactive species along the plasma jet axis was observed and this evolution provided a measure of the average and instantaneous plasma bullet velocity. The measured velocities are compared to the velocity obtained from the images of the plasma jet taken at different times by using an ICCD camera. It is found that the magnitude of the velocity measured by the electrical technique is little higher than the velocity measured by imaging and spectroscopy techniques, which produced similar results. However, in all cases, the bullet velocity is in the same order of magnitude (*105 m/s). It is also shown that each pulse generates a single bullet and this bullet propagates leaving a low density plasma channel behind it.
The main objective of this dissertation is to understand the formation of the plasma jet from the... more The main objective of this dissertation is to understand the formation of the plasma jet from the plasma pencil, and the propagation of the plasma jet in the ambient atmosphere where the effect of the external electric field is almost zero. Before investigating the formation and propagation phenomenon of the plasma jet, common physical properties of plasma jets are determined
2008 IEEE 35th International Conference on Plasma Science, 2008
ABSTRACT This paper reports on experimental measurements on an ionic wind generation device. Ioni... more ABSTRACT This paper reports on experimental measurements on an ionic wind generation device. Ionic wind is based on the entrainment of neutral atoms and molecules by ions being accelerated by an applied electric field. For a non-zero net average resultant force on the neutrals, single polarity ions are needed. In the case of a positive corona in air, molecular nitrogen positive ions dominate in the region between the cathode and the anode. The device used in ther experiments is a positive corona discharge in air between the end of sharp wires and a grounded mesh electrode. Measurements of the average wind speed as a function of different operating conditions are presented.
Abstract Using an electrical discharge to control airflow has recently been an active area of res... more Abstract Using an electrical discharge to control airflow has recently been an active area of research. This is mostly because of the interest in the manipulation of free airflow for aerodynamic applications. Corona discharges are well suited for these applications. In ...
Recently non-thermal atmospheric pressure plasma jets have been playing an important role in plas... more Recently non-thermal atmospheric pressure plasma jets have been playing an important role in plasma processing including biomedical applications. This is due to the ability of providing plasmas not confined by electrodes. In this paper we report experimental investigations ...
Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the... more Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the propagation of small plasma bullets traveling at very high velocities in ambient air. However, the propagation mechanisms are still not well understood. In this paper we ...
ABSTRACT To understand the self sustained propagation of the plasma jet/bullet in air under atmos... more ABSTRACT To understand the self sustained propagation of the plasma jet/bullet in air under atmospheric pressure, the ignition of the plasma jet/bullet, the plasma jet/bullet ignition point in the plasma pencil, the formation time and the formation criteria from a dielectric barrier configured plasma pencil were investigated in this study. The results were confirmed by comparing these results with the plasma jet ignition process in the plasma pencil without a dielectric barrier. Electrical, optical, and imaging techniques were used to study the formation of the plasma jet from the ignition of discharge in a double dielectric barrier configured plasma pencil. The investigation results show that the plasma jet forms at the outlet of the plasma pencil as a donut shaped discharge front because of the electric field line along the outlet's surface. It is shown that the required time for the formation of the plasma jet changes with the input voltage of the discharge. The input power calculation for the gap discharge and for the whole system shows that 56% of the average input power is used by the first gap discharge. The estimated electron density inside the gap discharge is in the order of 1011 cm−3. If helium is used as a feeding gas, a minimum 1.48×10−8 C charge is required per pulse in the gap discharge to generate a plasma jet.
2010 Abstracts IEEE International Conference on Plasma Science, 2010
ABSTRACT Recent studies have shown that low temperature atmospheric pressure plasma jets are form... more ABSTRACT Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the propagation of small plasma bullets traveling at very high velocities in ambient air. In this paper we report on the spatial evolution of the plasma jet properties investigated from the jet current density, where the jet current was measured by placing a lab-made probe along the jet propagation axis. The plasma jet was generated by a plasma pencil powered with high voltage short-duration pulses. The average current density, power density, electric field and electron density for every 0.5 cm plasma jet segment along the jet propagation trail were measured. The average peak current density, power density, and the electric field of the plasma jet were respectively 0.64 (A/cm2), 6.6 (kW/cm3) and 11.5 (kV/cm). The drift velocity of the electrons was calculated for the measured electric field along the jet axis and it showed a good agreement with the plasma jet's front velocity measured by ICCD image tracking. It also shows that the helium gas plays an important role in the jet propagation. The estimated average electron density in the plasma jet is 4.8+1011 cm3.
2010 Abstracts IEEE International Conference on Plasma Science, 2010
ABSTRACT Summary form only given. The propagation velocity of the atmospheric helium pulsed plasm... more ABSTRACT Summary form only given. The propagation velocity of the atmospheric helium pulsed plasma jet/bullet generated by the plasma pencil has been investigated through electrical and optical diagnostic techniques. The electrically-based technique measures the jet velocity from the time delay between the jet current peaks along the jet propagation axis. Using optical emission spectroscopy (OES) the temporal evolution of the reactive species along the plasma jet axis was observed and this evolution provided a measure of the average and instantaneous plasma bullet velocity. The measured velocities are compared to the velocity obtained from the images of the plasma jet taken at different times by using an ICCD camera. It is found that the magnitude of the velocity measured by the electrical technique is little higher than the velocity measured by imaging and spectroscopy techniques, which produced similar results. However, in all cases, the bullet velocity is in the same order of magnitude (*105 m/s). It is also shown that each pulse generates a single bullet and this bullet propagates leaving a low density plasma channel behind it.
The main objective of this dissertation is to understand the formation of the plasma jet from the... more The main objective of this dissertation is to understand the formation of the plasma jet from the plasma pencil, and the propagation of the plasma jet in the ambient atmosphere where the effect of the external electric field is almost zero. Before investigating the formation and propagation phenomenon of the plasma jet, common physical properties of plasma jets are determined
2008 IEEE 35th International Conference on Plasma Science, 2008
ABSTRACT This paper reports on experimental measurements on an ionic wind generation device. Ioni... more ABSTRACT This paper reports on experimental measurements on an ionic wind generation device. Ionic wind is based on the entrainment of neutral atoms and molecules by ions being accelerated by an applied electric field. For a non-zero net average resultant force on the neutrals, single polarity ions are needed. In the case of a positive corona in air, molecular nitrogen positive ions dominate in the region between the cathode and the anode. The device used in ther experiments is a positive corona discharge in air between the end of sharp wires and a grounded mesh electrode. Measurements of the average wind speed as a function of different operating conditions are presented.
Abstract Using an electrical discharge to control airflow has recently been an active area of res... more Abstract Using an electrical discharge to control airflow has recently been an active area of research. This is mostly because of the interest in the manipulation of free airflow for aerodynamic applications. Corona discharges are well suited for these applications. In ...
Recently non-thermal atmospheric pressure plasma jets have been playing an important role in plas... more Recently non-thermal atmospheric pressure plasma jets have been playing an important role in plasma processing including biomedical applications. This is due to the ability of providing plasmas not confined by electrodes. In this paper we report experimental investigations ...
Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the... more Recent studies have shown that low temperature atmospheric pressure plasma jets are formed by the propagation of small plasma bullets traveling at very high velocities in ambient air. However, the propagation mechanisms are still not well understood. In this paper we ...
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