Ionization wave propagation characteristics under different polarity of pulse waveforms in micro-DBD device driven by bipolar nanosecond pulse waveform

Abstract

Different spatiotemporal modes of ionization wave propagation at opposite polarity of bipolar pulses in a micro-dielectric barrier discharge structure device are investigated. The device is fabricated on a heavily doped n-type silicon substrate, and a 1 cm × 1 cm square cavity is formed on the 180 μm-thick polyimide film. Different modes of ionization wave propagation determined by the polarity of bipolar pulses are observed, and the details of streamerlike mode and wavelike mode under positive and negative half cycles of pulses are investigated, respectively. The propagation speeds of streamerlike ionization waves and wavelike ionization waves are ∼120 km/s and ∼40 km/s on average and ∼150 km/s and ∼70 km/s in maximum, respectively. Different parameters of bipolar pulses, especially the rising time of pulses, are applied to the proposed device to explore the variation of ionization wave propagation properties. The results show that the modes of the ionization wave propagation are barely changed when the device is driven by different rising time pulses. However, the initial plasma generation time and propagation speed are greatly changed. With a decrease in the rising time from 400 ns to 50 ns, the initial plasma generation time is brought forward over 200 ns, and the ionization wave propagation speed is improved over 30% for both cases. The results imply great significance in the exploration of the dynamics of plasma discharge evolution and regulation of plasma discharge properties through manipulating the pulse parameters.

Co-effect of dielectric layer material and driving pulse polarity on the spatial emission intensity distributions of micro dielectric barrier discharge

“…Figure 9(a) illustrates that a single discharge with one primary and several small pulses of currents (including displacement current and discharge current) is captured by the current probe cascaded to the ground, and the duration time of discharge is ∼140 ns at 50 ns rising time. With an increase of pulse rising time, the current waveform transforms from a single mode to a multiple mode, which has several comparable current peaks, and this is consistent with our previous work [25]. This behavior is similar to the self-pulsing discharge that is a typical feature of DBDs in the Townsend mode [31], which is mainly attributed to the discharge of residual metastable particles 3 P 1 and 3 P 2 in pure Ar with a lifetime of ∼10 −5 s, generated by the previous avalanche and remaining in the discharge space.…”

“…The loss of electrons due to the consumption on the sidewalls or dissociative recombination in the gas phase, as well as the plasma expansion surmounted on the SU-8 barrier, which is facilitated by the charges deposited on the sidewalls, are involved in such processes [24]. The microplasmas propagate from the initial discharge position to the undischarged region, and similar propagation has been reported in our previous work [25], though the device structures differ. The microplasma morphologies displayed in figures 5(a) and (b) were undergoing propagation, which induces the inhomogeneous emission intensity distribution.…”

A microplasma device and its switching behavior triggered by modulated pulse signal

“…When a gate voltage is applied, the charged particles in the discharge channel are attracted to the dielectric layer and substrate surface due to E radial , and the surface charges form the reverse electric field E surface as shown in figure 7, which is opposite to E radial . The total radial electric field strength will be weakened because of the combined action of E surface and E radial [25]. E radial blocks the formation of the channel plasma current, while E axial is superimposed on E DS to pre-discharge, which is conducive to the formation of channel current.…”

Ionization wave propagation of a surface dielectric barrier discharge with a flexible-structure plasma sheet

“…SIWs are observed by an extending luminous region in experiments, which demonstrates the location where the new breakdown occurs [23]. Simulations have also been carried out that focus on the characteristics of SIW propagation [24][25][26][27]. The observation of multiple SIW propagation on curved gas-solid interfaces when flexible plasma sources conform to different curvatures still needs contributions, and the inherent mechanisms behind their evolution are not fully understood.…”