Atmospheric-pressure plasma transfer across dielectric channels and tubes

Abstract

Atmospheric-pressure plasma transfer refers to producing an ionization wave (IW) in a tube or channel by impingement of a separately produced IW onto its outer surface. In this paper, we report on numerical and experimental investigations of this plasma transfer phenomenon. The two tubes, source and transfer, are perpendicular to each other in ambient air with a 4 mm separation with both tubes being flushed with Ne or a Ne/Xe gas mixture at 1 atmosphere pressure. The primary IW is generated in the source tube by ns to µs pulses of ±25 kV, while the transfer tube is electrodeless, not electrically connected to the first and at a floating potential. The simulations are conducted using a two-dimensional (2D) plasma hydrodynamics model with radiation transport, where the three-dimensional tubes in the experiments are represented by 2D channels. Simulations and experiments show that the primary IW propagates across the inter-tube gap and upon impingement induces two secondary IWs propagating in opposite directions in the transfer tube. Depending on the polarity of the primary IW in the source tube, the secondary IW in the transfer tube can have polarities either the same or opposite to that of the primary IW. The speed and strength of both the primary and secondary IWs depend on the rate of rise of the voltage pulse in the source tube. The modelling results were found to agree well with the behaviour of plasma transfer observed using nanosecond intensified charge-coupled device imaging.

Patterns of Plasma Bullet in Plasma Jets

“…where m * (m) is the effective (bare) mass of an electron with values guessed as m * ∼ (1 ∼ 100)m, and this is in good correspondence with our experiments [8], as shown in Table I.…”

Electrical, Thermal and Optical Parametric Study of Guided Ionization Waves Produced with a Compact μs-Pulsed DBD-Based Reactor

“…A build-up of charges on the dielectric surfaces induces an electrical field, which is opposite to the external one, limiting thus the discharge current and avoiding any transition to arc. Although "APPJs" appear as uniform luminous "plumes" by naked-eye observation, it has been demonstrated recently that they consist of ultrafast discrete "plasma bullets" or, more correctly in physical terms, guided streamer-like ionization waves [3][4][5][6][7][8][9], which are guided by the dielectric material (usually cylindrical) and the channel of a preselected noble gas (usually helium or argon).…”

Atmospheric Pressure Plasma Penetration inside Flexible Polymeric Tubes

“…[24][25][26][27] To help the understanding of the plasma processes occurring during plasma treatment of tubes, modeling of plasma propagation inside capillaries has already been performed. [28][29][30][31][32] However, the question on how the plasma jet itself penetrates inside tubes still remains largely unanswered. To cope with this lack of information, this paper intends to investigate the processes of plasma propagation inside small tubes: the plasma jet is generated in a quartz capillary and only afterwards directed to propagate inside different tube samples with a small gap being present between the plasma jet set-up and the beginning of the tube samples.…”