Special Session 121: Numerical techniques for the description of charged particles transport
Contents
We discuss Implicit-Explicit (IMEX) Runge Kutta methods which are particularly adapted to stiff
kinetic equations of Boltzmann type. We consider both the case of easy invertible collision operators and the
challenging case of Boltzmann collision operators. We give sufficient conditions in order that such methods are
asymptotic preserving and asymptotically accurate. Their monotonicity properties are also studied. In the case
of the Boltzmann operator the methods are based on the introduction of a penalization technique for the collision
integral. This reformulation of the collision operator permits to construct penalized IMEX schemes which work
uniformly for a wide range of relaxation times avoiding the expensive implicit resolution of the collision operator.
Finally we show some numerical results which confirm the theoretical analysis.