Plans d'accès
Webmail
Accueil > Pages Personnelles > G > Olivier Guaitella > Plasma jets interaction with surfaces
Plasma jets interaction with surfaces
General information on the project "Plasma jets interaction with surfaces"
Starting date at LPP : 2013
Person involved at LPP : Elmar Slikboer, Marlous Hofmans, Olivier Guaitella
Main Collaborations :
The team of Ana Sobota from TU/e in Eindhoven (The Netherlands)
The team of Enric Garcia-Caurel from LPICM at Ecole Polytechnique
Main Funding : Project RESPIRE from Chaire Energie Durable EDF - Ecole Polytechnique
Context of plasma applications at atmospheric pressure
A major trend in our community over the last 20 years has been the considerable increase in applications of cold plasma at atmospheric pressure. The indoor air treatment, the polymer deposition, biomedical applications,CO2 recycling are only a few examples of the many ideas that have been explored. Although microwave, glidarc, RF discharges are studied, in the vast majority of cases, cold plasmas generated at atmospheric pressure are corona or Dielectric Barrier Discharges (DBD) because of their simplicity of use.
A DBD ignited in air, CO2 or any molecular gases will most of the time develop into a filamentary regime corresponding to the ignition of multiple discharges growing through "streamer" breakdown mechanism (or "ionization waves"). These streamers are occurring randomly in time and space, lasting only a few nanoseconds, and having a typical diameter of few hundreds microns. Their interaction with complex surfaces is therefore extremely challenging to study and papers addressing this issue are rare.
The plasma filaments are often used to modify material surfaces but it is evident that in turn, the properties of material to be treated are strongly affecting the plasma dynamic as well. However beyond this general statement, the mechanisms at stake in the interaction between an ionization wave and surfaces are still poorly understood. The best fluid models describing streamer development often treat the surface only with a dielectric constant and an effective secondary electron emission coefficient. The nature, the life time and the mobility of charge adsorbed on dielectric material, the modiffication of gas dynamic above a target, the potential re-distribution induced above a floating conductive target, the role of micro and nano-porosity of the material are just a few examples of the many questions that remain unanswered to date.
Our work on the topic is dedicatedto the combination of advanced diagnostics both in the plasma above the target and inside the target exposed to plasma. We have for instance successfully performed measurement by Stark polarization spectroscopy (tomeasure Efield), Thomson and Raman scattering (electron density and gascomposition), and we have developped a new technique for in situ imaging of target modification under plasma exposure called Mueller polarimetry.
More details on our project can be found here and here
