The main concern of the present paper is the study of the multi-scale dynamics of thermonuclear fusion plasmas via a multi-species Fokker-Planck kinetic model. One of the goals is the generalization of the standard Fokker-Planck collision operator to a multispecies one, conserving mass, total momentum and energy, as well as satisfying Boltzmann's H-theorem. Secondly, the paper investigates in more details the reduced model used for the electron description in present simulations, and which considers the electrons in a thermodynamic equilibrium (adiabatic regime), whereas the ions are kept kinetic. On the one hand, we perform some mathematical asymptotic limits to obtain in the electron/ion low mass ratio limit the above-mentioned electron adiabatic regime. On the other hand, we develop a numerical scheme , based on a Hermite spectral method, and perfom numerical simulations to illustrate and investigate in more details this asymptotics.
翻译:本文的主要关切是通过多种物种Fokker-Planck动动模型研究热核聚变等离子的多尺度动态,其目标之一是将标准的Fokker-Planck碰撞操作员普遍化为多种物种之一,即保护质量、总动力和能量,以及满足Boltzmann的H-神话。第二,本文更详细地研究目前模拟中电子描述所用的减少型号,该模型考虑到热力平衡中的电子(非对称系统),而离子则保持动能。一方面,我们执行一些数学的微量限制,以便在电子/离子低质量比率中限制上述电电离子分解系统。另一方面,我们根据Hermite光谱法制定了一个数字计划,并用 Perfom 数字模拟来更详细地说明和调查这种脉冲。