Influence of nitrogen and oxygen admixture on the development of helium atmospheric-pressure plasma jet

Kong, Delin; Zhu, Ping; He, Feng; Han, Ruoyu; Yang, Bingyan; Wang, Manyu; Ouyang, Jiting

doi:10.1063/5.0031345

Cited by 19 publications

(13 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This discharge behavior facilitates the deposition and accumulation of the electrons and charges from successive discharges at the same locations in the d-zone [28,29], which can contribute to the formation of a non-uniform discharge [30][31][32] that represented as a discharge spot at the wall tube, wherein filaments initiated and elongated itself towards the tube nozzle. However, the observed discharge patterns differ from those found in conventional He plasma jet devices using the same electrode configuration [24], wherein the discharge hugged the tube wall and the ionization waves move with no side branching through the entire tube. Moreover, homogenous discharge was observed in addition to the filamentary discharge in the present configuration, as discussed in detail in section 4.3.…”

Section: Mechanism Of the Swirling Discharge In He-pccontrasting

confidence: 60%

“…This trend of discharge mode with the N 2 is qualitatively in agreement with that in He dielectric barrier discharge [53,54]; however, the device configuration might be the reason for the change in the critical impurity values. In addition, the maximum N 2 content that can be used to launch a jet was 1%, which is much smaller than that found in narrow conventional tubes, where a jet could be launched at N 2 content of 4% [24].…”

Section: Tunability Of the Discharge Pattern In He-pcmentioning

confidence: 74%

“…The present study indicates that the location of the PD plays another important role in the discharge mechanism and jet formation, as depicted in figure 3. Unlike conventional jet devices used narrow tubes with same electrode configuration [24], it is difficult to obtain a jet from a wide tube without using a PD or when the PD is out of the electrode gap, despite strong discharge appears in the gap at higher applied voltages (figure 3(a)). On the other hand, locating the PD in the electrode gap leads to the formation of a stable jet, even at smaller electrode gaps and applied voltages.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Abdelaziz¹,

Teramoto²,

Kim³

2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The generation of a large cold plasma jet while maintaining the reproducibility and homogeneity of the discharge is one of the major challenges encountered by the plasma community to efficiently apply this technology in the industry. Here, we report on the discharge in a recently developed device called the plasma candle (PC), wherein a stable plasma jet with a diameter of 20 mm can be generated at atmospheric pressure and temperature. Unlike the discharge morphology previously reported for conventional plasma jet devices, the unique configuration of PC device resulted in distinctive discharge patterns. Homogenous discharge was generated in the electrode gap and followed by a swirling discharge toward the tube nozzle. Fast photography and electrical measurements revealed that filament propagation and its morphology form the visually observable swirl discharge. Detailed analysis indicated that residual helium metastable species (Hem) and their penning ionization play an essential role in the discharge mode and its transition, which was verified by changing the feeding gas and the frequency of the applied voltage. For instance, it is found that only filamentary discharge was observed along the entire tube at frequencies less than 3 kHz, at which the time between consecutive discharges was long enough for Hem decay. Consequently, the homogenous discharge pattern was recovered by increasing the pre-ionization levels by adding a trace of impurities (N2, O2 or H2O) to the feeding gas. However, the level of these impurities must be carefully adjusted to achieve a homogenous discharge without negatively affecting the jet properties. A trivial change in the gas impurity, in the range of adsorption and desorption of water from the gas tubing, is sufficient to cause a noticeable change and instability in the discharge mode. This finding is critical to predicting the production of reactive species and plasma-surface interaction for different applications.

show abstract

Section: Mechanism Of the Swirling Discharge In He-pccontrasting

confidence: 60%

Section: Tunability Of the Discharge Pattern In He-pcmentioning

confidence: 74%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Abdelaziz¹,

Teramoto²,

Kim³

2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…The kinetics of O 2 and H 2 O containing APPJ have been investigated numerically by several studies [19][20][21][22]. Our previous work [23] studied the influence of O 2 admixtures on the evolution process of He APPJ.…”

Section: Introductionmentioning

confidence: 99%

Influence of different O₂/H₂O ratios on He atmospheric pressure plasma jet impinging on a dielectric surface

Liu¹,

Wang²,

Lin³

et al. 2021

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

A two dimensional (2D) axisymmetric fluid model is built to investigate the effect of different O2 and H2O admixture on the plasma dynamics and the distribution of reactive species in He atmospheric pressure plasma jet (APPJ). The increase of O2: H2O ratio slows down both the intensity and the propagation speed of ionization wave. Due to the decrease of both H2O ionization rate and H2O Penning ionization as well as the stronger electronegativity of O2, the increase of O2: H2O ratio results in a significant reduction of electron density in the APPJ, which restricts the occurrence of electron collision ionization reactions and inhibits the propagation of plasma. The excitation energy loss of O2 is not the reason for the weakening of the plasma ionization wave. The densities of O2+, O- and O2- increase with the rise of O2 admixture while H2O+ decreases due to the decrease of electron density and H2O concentration. OH- density is affected by both the increase of O- and the decrease of H2O so it shows peak in the case of O2: H2O=7:3. O is mainly produced by the excitation reactions and the electron recombination reaction (e + O2+ → 2O), which is directly related to the O2 concentration. OH is mainly produced by e + H2O → e + H + OH so the OH density decreases due to the decrease of electron density and H2O concentration with the increase of O2: H2O ratio. On the dielectric surface when the propagation of streamer extinguishes, O flux shows an upward trend while the OH flux decreases, and the propagation distance of O and OH decreases with the increase of O2: H2O ratio.

show abstract

“…Radio frequency (RF-) driven atmospheric pressure microplasma jets (µAPPJs) have gained considerable scientific attention in the last few years due to their effectiveness in generating reactive species [1][2][3][4][5][6]. This ability makes microplasma jets a versatile tool having applications in a variety of areas, such as plasma medicine (sterilization, wound healing, cancer treatment) [7][8][9][10][11][12], and materials processing [13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Electron power absorption in micro atmospheric pressure plasma jets driven by tailored voltage waveforms in He/N$_2$

Vass,

Wilczek,

Schulze

et al. 2021

Preprint

View full text Add to dashboard Cite

In atmospheric pressure capacitively coupled microplasma jets, Voltage Waveform Tailoring (VWT) was demonstrated to provide ultimate control of the Electron Energy Distribution Function (EEDF), which allows to enhance and adjust the generation of selected neutral species by controlling the electron power absorption dynamics. However, at the fundamental level, the physical origin of these effects of VWT remained unclear. Therefore, in this work, the electron power absorption dynamics is investigated in a He/N 2 jet with a nitrogen concentration of 0.05% driven by a valleys voltage waveform at a base frequency of 13.56 MHz for different numbers of harmonics using a self-consistent Particle in Cell simulation coupled with a spatio-temporally resolved analysis of the electron power absorption based on moments of the Boltzmann equation. Due to the local nature of the transport at atmospheric pressure, ohmic power absorption is dominant. Increasing the number of harmonics, due to the peculiar shape of the excitation waveform the sheath collapse at the grounded electrode is shortened relative to the one at the powered electrode. As a consequence, and in order to ensure flux compensation of electrons and positive ions at this electrode, a high current is driven through the discharge at the time of this short sheath collapse. This current is primarily driven by a high ohmic electric field. Close to the grounded electrode, where the electron density is low and the electric field is, thus, high, electrons are accelerated to high energies and strong ionization as well as the formation of a local electron density maximum are observed. This electron density maximum leads to a local ambipolar electric field that acts as an electric field reversal and accelerates electrons to even higher energies. These effects are understood in detail to fundamentally explain the unique potential of VWT for EEDF control in such plasmas.

show abstract

Influence of nitrogen and oxygen admixture on the development of helium atmospheric-pressure plasma jet

Cited by 19 publications

References 53 publications

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Influence of different O₂/H₂O ratios on He atmospheric pressure plasma jet impinging on a dielectric surface

Electron power absorption in micro atmospheric pressure plasma jets driven by tailored voltage waveforms in He/N$_2$

Contact Info

Product

Resources

About

Influence of nitrogen and oxygen admixture on the development of helium atmospheric-pressure plasma jet

Cited by 19 publications

References 53 publications

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Unveiling the formation and control of unique swirling discharge pattern in helium plasma candle device

Influence of different O2/H2O ratios on He atmospheric pressure plasma jet impinging on a dielectric surface

Electron power absorption in micro atmospheric pressure plasma jets driven by tailored voltage waveforms in He/N$_2$

Contact Info

Product

Resources

About

Influence of different O₂/H₂O ratios on He atmospheric pressure plasma jet impinging on a dielectric surface