Plasmas collisionnels et réactifs © Olivier Guaitella, LPP - École Polytechnique

Collisional and reactive plasmas

Collisional and reactive plasmas

  • Laboratories: LPP, ONERA, IJLRA, LISE
  • Number of researchers involved: about 30
  • Publications (2012-2018): more than 250

This theme brings together fields of investigation ranging from plasma-assisted combustion, to applications related to biology and the environment and are directly linked with current societal issues (medicine, water treatment, pollution, recycling of CO2, etc.).

Indeed, important questions are discussed in our laboratories and with our industrial partners (SAFRAN, Onera) in order to define the best characteristics of a plasma to initiate combustion. This involves, for example, identifying the spatial and temporal distribution of the energy injected into the plasma, as well as understanding how the energy between excitation of charged particles or heating of the gas is distributed. Our goal: to optimize the plasma for different combustion applications.

Regarding propulsion, it is also essential to better understand how to control the acceleration processes and improve containment to reduce losses. Likewise, with regard to aeronautical applications, it is now necessary to improve local or filamentary energy deposition (HF or laser deposition) for aerodynamic plasmas while understanding how to control the flows.

Concerning plasma mirrors, the community is also wondering about the generation of plasmas for the absorption or reflection of electromagnetic waves in the microwave domain. This is the equivalent of an "optical" plasma in the visible where the plasma behaves like a medium that allows radiation to be manipulated.

About the numerical simulation of collisional and reactive plasmas, an important subject concerns the modeling of atmospheric reentry plasmas to combine MHD modeling and modeling of in equilibrium and out of equilibrium plasmas in supersonic and hypersonic flows.

Finally, on the subject of plasma chemistry, several teams are studying the impact of a positively or negatively charged plasma (electronegative gas or ionic plasma) and the physicochemical processes involved in ion-molecule collisions. For this, it is necessary to define the dynamic properties (flow) of plasmas, and the possible applications for propulsion or micro-electronics.

On all these topics, it is necessary to develop a comprehensive database of collision cross-sections for insertion into laboratory plasma codes and models, relying on sharing and interoperability tools such as VAMDC. These cross sections already exist today, but precise knowledge of chemical reactivities is limited to certain elements only. This point is common to the following theme.

ILLUSTRATION: The European PIONEER project (IJLRA, LPP) is a doctoral training program in joint supervision “Innovative Training Network” (MSCA action) which will allow the development of catalytic materials capable of taking advantage of reactive plasma species, and of designing sources of plasma best suited to each CO2 recycling process.. © Olivier Guaitella, LPP - École Polytechnique.