Aligned interpolation and application to drift kinetic semi-Lagrangian simulations with oblique magnetic field in cylindrical geometry

Guillaume Latu (1) , Michel Mehrenberger (2, 3, 4) , M Ottaviani (5) , Eric Sonnendrücker (2)

1 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique
2 IPP - Max-Planck-Institut für Plasmaphysik [Garching]
3 TONUS - TOkamaks and NUmerical Simulations
4 IRMA - Institut de Recherche Mathématique Avancée
5 Dipartimento di Fisica [Roma La Sapienza]

We introduce field aligned interpolation for Semi-Lagrangian schemes, adapting a method developed by Hariri-Ottaviani [7] to the semi-Lagrangian context. This approach is vali-dated on the constant oblique advection equation and on a 4D drift kinetic model with oblique magnetic field in cylindrical geometry. The strength of this method is that one can reduce the number of points in the longitudinal direction. More precisely, we observe that we gain a factor |n| |n+mι| (where ι is the inverse safety factor), with respect to the classical approach, for the typical function sin(mθ + nϕ).

Domaines: Plasmas; Analyse numérique [math.NA]; Equations aux dérivées partielles [math.AP]

Guillaume Latu, Michel Mehrenberger, M Ottaviani, Eric Sonnendrücker. Aligned interpolation and application to drift kinetic semi-Lagrangian simulations with oblique magnetic field in cylindrical geometry. [Research Report] IRMA. 2014. ⟨hal-01098373⟩