On the interpretation of kinetic effects from ionization in fluid models and its impact on filamentary transport

In regions where a plasma is not fully ionized, such as the edge and scrape-off layer (SOL) in tokamak, charged particles may be subject to strong sources from interactions with neutral atoms molecules. Such sources, e.g., electron impact ionization, can introduce kinetic effects, ionized have flow velocity temperature different that of main species. If treated conventional fluid picture, this effect emerges frictional heating term. paper, physics term discussed, both for un-magnetized magnetized plasmas. The source terms are mapped back provide consistent picture future model comparison. limits low high ratios between rates thermalization multi-ion species drift-fluid applied assess on SOL drift-plane transport. This done by modeling seeded blob ions follow either single- or double-Maxwellian distribution function (VDF). It found robustness VDF limited vorticity ensure effects perpendicular evolution small, even limit ionization rate ratio, ion significant.