Simulation on the Plasma Dynamics of a Needle-Plate Barrier Discharge Packed With a Single Dielectric Bead

• Published in: IEEE transactions on plasma science Vol. 52; no. 5; pp. 1619 - 1630
• Main Authors: Li, Xuechen, Zhang, Lulu, Chen, Kuan, Ran, Junxia, Pang, Xuexia, Jia, Pengying
• Format: Journal Article
• Language: English
• Published: IEEE 01.05.2024
• Subjects: Dielectrics; Discharges (electric); Electrons; Needles; Packed-bed dielectric barrier discharge (DBD); particle-in-cell/Monte Carlo collision (PIC/MCC) method; plasma dynamics; Plasmas; streamer; Surface discharges; Surface morphology
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2024.3401040

The packed-bed dielectric barrier discharge (DBD) is popular in plasma catalysis, whose performance is determined by plasma dynamics. In this article, the plasma dynamics have been simulated with a needle-plate DBD packed with a single bead by a particle-in-cell/Monte Carlo collision (PIC/MCC) method. Simulation results reveal that the packed DBD is composed of a positive streamer on the bead surface, a local discharge near the contact point, and a plate-surface discharge with high permittivity (<inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>) of the bead. After passing through the bead midpoint between the needle tip and the contact point, the streamer continues propagating on the bottom half bead surface until it meets the local discharge. In contrast, the local discharge is absent with low <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>. The streamer propagates vertically toward the plate after the midpoint. Compared with high <inline-formula> <tex-math notation="LaTeX">\varepsilon ,n_{e},E </tex-math></inline-formula>, and surface streamer velocity are lower, and the plasma channel is wider with low <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>. For different <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula>, the densities of <inline-formula> <tex-math notation="LaTeX"> \mathrm {N}_{2}^{+},\mathrm {O}_{\mathrm {2,}}^{+} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">\mathrm {O}_{2}^{-} </tex-math></inline-formula> follow the similar temporal trend with <inline-formula> <tex-math notation="LaTeX">n_{e} </tex-math></inline-formula>. The deposited charge is a positive ion on the top half bead surface and an electron on the bottom half bead surface. In addition, <inline-formula> <tex-math notation="LaTeX">n_{e} </tex-math></inline-formula> and E increase with the increase of voltage amplitude (<inline-formula> <tex-math notation="LaTeX">V_{a} </tex-math></inline-formula>). If <inline-formula> <tex-math notation="LaTeX">V_{a} </tex-math></inline-formula> is too low, the surface streamer stops propagating after a certain distance, which increases with the increase of <inline-formula> <tex-math notation="LaTeX">V_{a} </tex-math></inline-formula>. Even with low <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">\varepsilon =2 </tex-math></inline-formula>), the local discharge can be induced if <inline-formula> <tex-math notation="LaTeX">V_{a} </tex-math></inline-formula> is sufficiently high. All the results mentioned above reveal that both <inline-formula> <tex-math notation="LaTeX">\varepsilon </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">V_{a} </tex-math></inline-formula> affect the plasma dynamics greatly.