Derivation of fluid model for Massive Mass injection in Tokamaks

A plasma consists of a set of charged and uncharged particles (atoms, molecules, ions, and electrons) and exhibits a collective behavior due to the interactions among these particles. If a plasma is fully ionized, it contains only charged particles, i.e., ions (i) and electrons (e), interacting via ‘Coulomb collisions.’ Partially ionized also includes, in addition to charged particles, neutral particles (atoms or molecules of the same or different gases). Such plasma can occur naturally, for example: Astrophysical plasma, by injecting neutral gases in a tokamak plasma. Many types of interactions are possible when a plasma contains charged as well as neutral particles. These particles can interact with each other via elastic collisions, Coulomb collisions, and atomic reactions. These nuclear reactions can be excitation, ionization, recombination, and charge exchange.
In this presentation, starting with generic multifluid modeling of the mixture, we will use the premixed assumptions to derive models for Massive Mass Injection (MMI). We will also propose a simulation of the Shattered Pellet Injection (SPI) system in the tokamak JET (Joint European Tokamak). Shattered Pellet Injection is the ITER Disruption Mitigation System (DMS) reference concept. 

This is joint work with A. Bohle, E. Nardon, D. Di, G. Huijsmans, S. Pamela, and Jorek Team.

References

[1] M Hoelzl, GTA Huijsmans, SJP Pamela, M Becoulet, E Nardon, FJ Artola, B Nkonga, et al. The JOREK nonlinear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas NF 61, 065001 (2021) 

[2] A. Bhole, Stabilized C1-bicubic finite element method for nonlinear MHD modeling of tokamak plasma, PhD (2021). 


[3] D. Hu, E. Nardon, M. Hoelzl, F. Wieschollek, M. Lehnen, GTA. Huijsmans, DC. van Vugt, S-H. Kim JET Contributors, JOREK Team. Radiation asymmetry and MHD destabilization during the thermal quench after impurity shattered pellet injection. Nuclear Fusion 61, 026015(2021) 


[4] A. Bhole, B. Nkonga, J. Costa, G.T.A. Huijsmans , S.J.P. Pamela , M. Hoelzl and JOREK Team. Stabilized bi-cubic Hermite B ́ezier finite element method with application to Gas-plasma interactions occurring during massive material injection in Tokamaks, submitted to Computer Methods in Applied Mechanics and Engineering (2022).