Abstract
The dynamics of ionization waves (IWs) in atmospheric pressure discharges is fundamentally determined by the electric polarity (positive or negative) at which they are generated and by the presence of memory effects, i.e. leftover charges and reactive species that influence subsequent IWs. This work examines and compares positive and negative IWs in pulsed plasma jets (1 upmu s on-time), showing the difference in their nature and the different resulting interaction with a dielectric BSO target. For the first time, it is shown that a surface charging memory effect is produced, i.e. that a significant amount of surface charges and electric field remain in the target in between discharge pulses (200 upmu s off-time). This memory effect directly impacts IW dynamics and is especially important when using negative electric polarity. The results suggest that the remainder of surface charges is due to the lack of charged particles in the plasma near the target, which avoids a full neutralization of the target. This demonstration and the quantification of the memory effect are possible for the first time by using an unique approach, assessing the electric field inside a dielectric material through the combination of an advanced experimental technique called Mueller polarimetry and state-of-the-art numerical simulations.
Highlights
Plasma jets are very interesting for the study of interactions between low-temperature plasmas at atmospheric pressure and surfaces
ionization waves (IWs) propagate in a noble gas that flows through a dielectric tube and expands into air, forming a plume, where the discharge interacts with target surfaces
We have shown that combining electric field measurements in He plasma jets with plasma simulations provides a highly reliable and detailed characterization of electric field and surface charge on targets[34,35,36]
Summary
Plasma jets are very interesting for the study of interactions between low-temperature plasmas at atmospheric pressure and surfaces In these devices, IWs propagate in a noble gas that flows through a dielectric tube and expands into air, forming a plume, where the discharge interacts with target surfaces. In this article we show how the choice of applied voltage pulse affects the surface charging dynamics and the leftover charges and electric field in a BSO dielectric target impacted by a plasma jet. The differences of discharge dynamics and interaction with the dielectric BSO target for the different pulses of applied voltage are presented These reveal, for the first time, the direct influence of leftover surface charges as memory effect. This includes the description of how leftover surface charges are considered in simulations, why is pulse width slightly different in experiments and simulations and how to compare results in such conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
