Method for loading marker particles for arbitrary distribution functions and application for simulation of high-energy ion dynamics in tokamak plasma

トカマクプラズマにおける高エネルギーイオン運動論のシミュレーションのための任意の分布関数をマーカ粒子で離散化するための手法

Bierwage, A.; Di Troia, C.*; Zonca, F.*

Bierwage, A.; Di Troia, C.*; Zonca, F.*

A new software tool is presented which allows to initialize particle simulations of magnetically confined plasmas with an arbitrary particle distribution function. Besides facilitating simulations with (in principle) arbitrary spatial localization and velocity-space anisotropicity, the distinguishing feature of this tool is that it allows to construct an exact kinetic equilibrium for cases where magnetic drift orbits play an important role. One timely example is the interaction between energetic ions and magnetohydrodynamic modes in tokamaks used to study burning plasma conditions. In such cases, input data that consists of measurable (and physically meaningful) quantities is not sufficient to uniquely describe the equilibrium distribution function. The additional information required to design an exact equilibrium from incomplete input data is obtained by pre-computing the unperturbed drift orbits of all phase-space samples. Marker particles are distributed along these trajectories (excluding loss orbits) and appropriate weight factors are assigned. First simulation results with the new marker loading module will be presented as they become available.