Plasma Chemistry, Laboratory

International audiencePlasma Chemistry refers to chemical processes occurring in partially ionized media. In planetary science, plasma setups, such as capacitively coupled plasma, corona discharge, or spark discharge, are often used as proxies to simulate the complex chemical networks triggered in upper planetary atmospheres by Far- and Extreme-UV stellar radiations (Szopa et al. 2006; Tigrine et al. 2016; He et al. 2019). Such chemical systems couple the reactivity of neutral species, positive and negative ions, and electrons, involving, for instance, neutral-neutral reactions, ion-neutral reactions, and dissociative recombination reactions. The densities (and temperatures) of the neutrals, the ions, and the electrons are highly variable according to the plasma source considered, leading to varying possible degrees of ionization (Cable et al. 2012)