摘要 :
In this review we describe the kinetics of non-equilibrium discharge plasma when the ion composition is dominated by water or hydrocarbon ions. Plasmas with water ions are formed in atmospheric discharges and discharges in the pre...
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In this review we describe the kinetics of non-equilibrium discharge plasma when the ion composition is dominated by water or hydrocarbon ions. Plasmas with water ions are formed in atmospheric discharges and discharges in the presence of liquid water or water vapor, including plasma applications for air purification, medicine and combustion. Reactions with hydrocarbon ions play an important role in interstellar chemistry, plasma enhanced chemical vapor deposition, synthetic diamond film deposition and plasma assisted combustion. The modeling of water ion chemistry and chemistry of hydrocarbon-containing plasmas requires large amount of data on the rates of ion formation and loss. This review provides the core database for the rate coefficients describing the kinetics of charged particles in plasmas with water and hydrocarbon ions as a function of temperature, pressure, and local electric field. Particular attention is given to cluster ions, which are important at not-too-low gas pressures, whereas the majority of studies of ion-molecule reactions have been performed at low pressures in the absence of cluster ions. To illustrate importance of the described processes, the development of streamer discharges in long humid air gaps are discussed and the influence of water ions on the streamer properties is demonstrated. In addition, the decay of non-equilibrium plasma with water and hydrocarbon ions is analyzed in combustible gaseous mixtures excited by a repetitively pulsed nanosecond discharge.
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摘要 :
In this review we describe the kinetics of non-equilibrium discharge plasma when the ion composition is dominated by water or hydrocarbon ions. Plasmas with water ions are formed in atmospheric discharges and discharges in the pre...
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In this review we describe the kinetics of non-equilibrium discharge plasma when the ion composition is dominated by water or hydrocarbon ions. Plasmas with water ions are formed in atmospheric discharges and discharges in the presence of liquid water or water vapor, including plasma applications for air purification, medicine and combustion. Reactions with hydrocarbon ions play an important role in interstellar chemistry, plasma enhanced chemical vapor deposition, synthetic diamond film deposition and plasma assisted combustion. The modeling of water ion chemistry and chemistry of hydrocarbon-containing plasmas requires large amount of data on the rates of ion formation and loss. This review provides the core database for the rate coefficients describing the kinetics of charged particles in plasmas with water and hydrocarbon ions as a function of temperature, pressure, and local electric field. Particular attention is given to cluster ions, which are important at not-too-low gas pressures, whereas the majority of studies of ion-molecule reactions have been performed at low pressures in the absence of cluster ions. To illustrate importance of the described processes, the development of streamer discharges in long humid air gaps are discussed and the influence of water ions on the streamer properties is demonstrated. In addition, the decay of non-equilibrium plasma with water and hydrocarbon ions is analyzed in combustible gaseous mixtures excited by a repetitively pulsed nanosecond discharge.
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A 2D numerical simulation of the positive streamer properties was performed in 9-12 cm plane-to-plane air gaps for various pressures and water vapor contents. It was shown that an increase in air humidity leads to hampering the st...
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A 2D numerical simulation of the positive streamer properties was performed in 9-12 cm plane-to-plane air gaps for various pressures and water vapor contents. It was shown that an increase in air humidity leads to hampering the streamer development and to increasing the average critical electric field required for bridging the discharge gap. The effect of humidity was most profound at atmospheric pressure and decreased with decreasing pressure. The influence of water content on the streamer properties was explained by a decrease in the streamer channel conductivity due to dissociative recombination of electrons with positive hydrated ions and enhanced three-body electron attachment to O_2 molecules. The calculated critical electric field in humid air gaps was compared with available experimental data.
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Changes in the pulse amplitude, and voltage rise time do not cause a significant change in the field in the streamer channel, which remains at the level E_(ch) ～ 5 kV/cm in the range from 5 kV to 1000 kV. The length of the stream...
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Changes in the pulse amplitude, and voltage rise time do not cause a significant change in the field in the streamer channel, which remains at the level E_(ch) ～ 5 kV/cm in the range from 5 kV to 1000 kV. The length of the streamer propagation essentially depends on the anode radius (through velocity). The field in the channel depends on the electrode radius only at small distances. The pulse rise time has practically no effect on the field in the channel, streamer velocity and propagation distance. The kinetics of ionization and recombination significantly change both the electric field in the channel and the propagation distance of the streamer.
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摘要 :
Changes in the pulse amplitude, and voltage rise time do not cause a significant change in the field in the streamer channel, which remains at the level E_(ch) ～5 kV/cm in the range from 5 kV to 1000 kV. The length of the streame...
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Changes in the pulse amplitude, and voltage rise time do not cause a significant change in the field in the streamer channel, which remains at the level E_(ch) ～5 kV/cm in the range from 5 kV to 1000 kV. The length of the streamer propagation essentially depends on the anode radius (through velocity). The field in the channel depends on the electrode radius only at small distances. The pulse rise time has practically no effect on the field in the channel, streamer velocity and propagation distance. The kinetics of ionization and recombination significantly change both the electric field in the channel and the propagation distance of the streamer.
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Corona discharge occurs in the gaps with strongly non-uniform electric field. Corona discharges have been much studied on a laboratory scale and have been used in many technologies. Coronae referred to also as point discharges are...
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Corona discharge occurs in the gaps with strongly non-uniform electric field. Corona discharges have been much studied on a laboratory scale and have been used in many technologies. Coronae referred to also as point discharges are often initiated from the tips of trees, bushes, grass and other sharp ground objects under thunderstorm conditions. This happens due to atmospheric electric field intensification at these "points'. Such thunderstorm coronae are most often positive because the main lower cloud charge is generally negative. For the last decade, author's studies have shown that a thunderstorm corona initiated from the top of a high grounded structure can affect strongly the initiation of an upward lightning discharge from the high structure and that of an upward connecting leader that is formed in the electric field of an approaching downward lightning leader. The last process predetermines mostly lightning strike to the given structure since both of the leaders develop to meet each other.
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