Electric field measurements in a near atmospheric pressure nanosecond pulse discharge with picosecond electric field induced second harmonic generation

Goldberg, Benjamin M.; Chng, Tat Loon; Dogariu, Arthur; Miles, Richard B.

doi:10.1063/1.5019173

Cited by 76 publications

(91 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The E-FISH optical setup, shown in Fig. 2, is similar to the one used in [23], and essentially identical to that used in our recent work [24]. The vertically polarized probe laser beam (1064 nm fundamental output of an Ekspla PL2241B laser, pulse duration 30 ps, pulse energy 1.8 mJ) is directed horizontally along the discharge vertical center plane, and is focused on the discharge centerline by a 30 cm focal distance lens (see Fig.…”

Section: Experimental and Data Reductionmentioning

confidence: 99%

Electric field evolution in a diffuse ionization wave nanosecond pulse discharge in atmospheric pressure air

Chng¹,

Brisset²,

Jeanney³

et al. 2019

Plasma Sources Sci. Technol.

105

View full text Add to dashboard Cite

The time-resolved electric field in a fast ionization wave discharge in a diffuse nanosecond pulse discharge plasma in atmospheric pressure air is measured using the Electric Field Induced Second Harmonic (E-FISH) diagnostic. The electric field is placed on an absolute scale by calibration against a Laplacian field. At relatively low peak voltages, when the plasma is generated only near the pin high-voltage electrode, the electric field is measured ahead of the ionization wave during the entire voltage pulse, exhibiting a strong field enhancement compared to the Laplacian field, by about an order of magnitude. As the peak voltage is increased and the ionization wave traverses the laser beam, the electric field is measured both ahead of the wave and behind the ionization front, where the field drops rapidly due to the charge separation and plasma selfshielding. When the wave reaches the grounded electrode, the discharge transitions into a conduction phase in which the potential is redistributed within the gap. The electric field in the vicinity of the pin then increases again, following the applied voltage waveform for the rest of the pulse. The effective time resolution of the present measurements is 150 ps. Based on the single shot data, we find that the peak electric field in the wave front is moderately influenced by the applied voltage and varies between 160 to 210 kV/cm. This study demonstrates the viability of the E-FISH diagnostic for this class of atmospheric pressure discharges and paves the way for future in-depth studies of this particular problem.

show abstract

Section: Experimental and Data Reductionmentioning

confidence: 99%

Electric field evolution in a diffuse ionization wave nanosecond pulse discharge in atmospheric pressure air

Chng¹,

Brisset²,

Jeanney³

et al. 2019

Plasma Sources Sci. Technol.

105

View full text Add to dashboard Cite

show abstract

“…Development and experimental validation of higher fidelity ns pulse discharge models needs detailed non-intrusive measurements of the electric field in the plasma. Recently, remarkable progress has been made in development of a non-intrusive laser diagnostic technique for electric field measurements in air plasmas, fs/ps second harmonic generation (SHG) [18,19]. This method offers several advantages over the reduced electric field measurements by optical emission spectroscopy (OES) [20,21], including straightforward absolute calibration, measurement of individual components of the electric field vector, and capability of acquiring data over a much larger spatial domain and wider range of time scales, where plasma optical emission is not detected.…”

Section: Introductionmentioning

confidence: 99%

Electric field distribution in a surface plasma flow actuator powered by ns discharge pulse trains

Simeni

Tang

Frederickson

et al. 2018

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

Electric field vector components in a nanosecond pulse, surface dialectric barrier discharge plasma actuator are measured by picosecond second harmonic generation, for positive, negative, and alternating polarity pulse trains. Plasma images show that in the same polarity train, the positive polarity discharge develops as two consecutive surface ionization waves, while the negative polarity discharge propagates as a single diffuse ionization wave. In the alternating polarity train, both positive and negative polarity discharge plasmas become strongly filamentary. In all pulse trains, the measurement results demonstrate a significant electric field offset before the discharge pulse, due to the surface charge accumulation during previous discharges pulses. This demonstrates that charge accumulation is a significant factor affecting the electric field in the discharge, even at very low pulse repetition rates. Peak electric field measured in the alternating polarity pulse train is lower compared to that in same polarity trains. However, the coupled pulse energy in the alternating polarity train is much higher, by a factor of 3-4, most likely due to the neutralization of the surface charge accumulated on the dielectric during the previous, opposite polarity pulses. This suggests that plasma surface actuators powered by alternating polarity pulse trains may generate higher amplitude thermal perturbations, producing a stronger effect on the flow field. The present results show that the time scale for the electric field reduction in the plasma after breakdown is fairly long, several tens of ns, including the conditions when the discharge develops as a diffuse ionization wave. This suggests that a considerable fraction of the energy is coupled to the plasma at a relatively low reduced electric field, several tens of Townsend. At these conditions, the discharge energy fraction thermalized as rapid heating would remain fairly low, thus limiting the effect on the flow caused by the highamplitude localized thermal perturbations.

show abstract

“…We applied different DC voltages, and monitored the associated pump beam laser intensity and second harmonic intensity response to the laser shots. Note that the pump beam intensity is determined by integrating the waveform obtained by the photodiode over the full response time, and the second harmonic intensity is determined in the same way 22 . Fig.…”

mentioning

confidence: 99%

Electric field measurements under DC corona discharges in ambient air by electric field induced second harmonic generation

Cui

Zhuang

Zeng

2019

Applied Physics Letters

View full text Add to dashboard Cite

Electric field distribution is critically important for quantitative insights into the physics of non-equilibrium plasma like corona. To analyze the electric field as well as the ion flow (space charge) distribution under DC corona discharges, the ion flow model has been widely adopted; Kaptzov's assumption, which states the steady state electric field at the conductor surface remains at the corona onset value, serves as a boundary condition. In this letter, we investigate the electric field distribution under DC corona discharges between coaxial cylindrical electrodes in ambient air by electric field induced second harmonic generation with nano-second pulse laser beams. The electric field distribution (with or without corona discharge) is obtained. By comparing the measurements with the results predicted by the ion flow model for negative corona discharge, it is found that the electric field at the conductor surface is proportional to the current density of the corona discharge with a negative constant of proportionality. Therefore, for negative corona discharges, Kaptzov's assumption is valid only when the discharge current approaches zero or is small.A corona is a cold plasma that results from a locally enhanced electric field near an energized conductor or a metal tip, and has broad applications, such as the electrostatic precipitators 1 , polyester fabric 2 , polyaniline doping 3 and high voltage transmission line designs 4 . Therefore, regulating the corona discharge is greatly desired, especially for many engineering purposes. To better regulate the corona (as well as other non-equilibrium plasmas), the electric field distribution is critically important for quantitative insights because it is strongly correlated with the microphysical processes of discharges that involve electron transport, kinetics of ionization, electron energy partition, and generation of excited species and atoms 5,6 .However, when a self-sustained corona discharge emerges in a system, we are unable to calculate the electric field distribution by simply solving a Laplace equation. To analyze the spatial electric field distribution under corona discharges, the ion flow model, which accounts for most key features such as ion drift and recombination, has been widely adopted 7-9 . The model includes the transport equations and a Poisson equation.To make the model complete, the value of the electric field at the surface of the electrode, which serves as the boundary condition of the model 7-10 , is assumed to remain constant. The solution to the electric field and charge distributions under a corona discharge is sensitive to this value. Townsend first attempted to estimate this value and suggested that the electric field at the surface of the conductor remains at its onset value 11 . The basis of this assumption is that a reduction in value below the onset value results in the extinction of the discharge. Cobine suggested that a highly ionized region near a line conductor may require for a field greater than the onset field 12 . Nowadays, ...

show abstract

Electric field measurements in a near atmospheric pressure nanosecond pulse discharge with picosecond electric field induced second harmonic generation

Cited by 76 publications

References 22 publications

Electric field evolution in a diffuse ionization wave nanosecond pulse discharge in atmospheric pressure air

Electric field evolution in a diffuse ionization wave nanosecond pulse discharge in atmospheric pressure air

Electric field distribution in a surface plasma flow actuator powered by ns discharge pulse trains

Electric field measurements under DC corona discharges in ambient air by electric field induced second harmonic generation

Contact Info

Product

Resources

About