In this article an approximated version of the multi-species, non-linear Coulomb collision operator is derived via the use of a truncated moment expansion of the distribution function to compute the Rosenbluth potentials. The evolution of the distribution function due to the collision operator takes the form of a Fokker–Planck equation that can be efficiently solved by a Langevin approach in the particle-in-cell (PIC) framework. This kinetic collision operator is then implemented in the global gyrokinetic PIC code ORB5 while neglecting finite Larmor effects. This collision operator ensures exact conservation of density, total momentum and energy as expected. The neoclassical physics is also successfully retrieved by the code. Numerical aspects such as the noise control and the parallelisation of the code are presented in detail.

在本文中，通过使用分布函数的截断矩展开来计算罗森布鲁斯势，可以得出多物种非线性库仑碰撞算子的近似形式。由碰撞算子引起的分布函数的演化采用Fokker-Planck方程的形式，可以通过Langevin方法在单元中粒子（PIC）框架中有效地求解。然后，在忽略有限的拉莫尔效应的情况下，在全局回旋PIC代码ORB5中实现了该动力学碰撞算子。该碰撞算子确保了密度，总动量和能量的精确守恒。该代码还成功检索了新古典物理学。详细介绍了数字方面，例如噪声控制和代码的并行化。