Chaos in atmospheric pressure plasma jets

Abstract

Abstract:We report detailed characterization of a low-temperature atmosphericpressure plasma jet that exhibits regimes of periodic, quasi-periodic and chaotic behaviors. Power spectra, phase portraits, stroboscopic section and bifurcation diagram of the discharge current combine to comprehensively demonstrate the existence of chaos, and this evidence is strengthened with a nonlinear dynamics analysis using two control parameters that maps out periodic, period-multiplication, and chaotic regimes over a wide range of the input voltage and gas flow rate. In addition, optical emission signatures of excited plasma species are used as the second and independent observable to demonstrate the presence of chaos and period-doubling in both the concentrations and composition of plasma species, suggesting a similar array of periodic, quasi-periodic and chaotic regimes in plasma chemistry. The presence of quasi-periodic and chaotic regimes in structurally unbounded low-temperature atmospheric plasmas not only is important as a fundamental scientific topic but also has interesting implications for their numerous applications. Chaos may be undesirable for industrial applications where cycle-tocycle reproducibility is important, yet for treatment of cell-containing materials including living tissues it may offer a novel route to combat some of the major challenges in medicine such as drug resistance. Chaos in low-temperature atmospheric plasmas and its effective control are likely to open up new vistas for medical technologies.2

Sub-60 °C atmospheric helium–water plasma jets: modes, electron heating and downstream reaction chemistry

“…It is worth noting that the presence of two chaotic modes on either side of the bullet mode was not discussed in the first report of chaos in atmospheric plasma jets in a dry gas flow [50]. This has since been observed in atmospheric dry helium plasma jets [51]. So they are generic to atmospheric helium-containing plasmas.…”