Guiding Center Trajectories

Aziz Raouak, Ecole Francais Ensignement Techique,

The motion of charged particles in slowly varying electromagnetic fields is analyzed. The strength of the magnetic field is such that the gyro-period and the gyro-radius of the particle motion around field lines are the shortest time and length scales of the system. The particle motion is described as the sum of a fast gyro-motion and a slow drift velocity. The deflections in two-particle collisions. Rather, their orbits are deflected through weak interactions with many particles simultaneously. Hence, the effects of collisions can be best described statistically, in terms of distributions of particles. This behaviour is qualitatively observed in test-particle numerical experiments. The ability of numerical integration methods like the ‘classical’ fourth-order Runge–Kutta integration scheme or a third-order symplectic integrator to reproduce the statistics is analysed.