Particle-In-Cell, a numerical method at the border between astrophysics and laboratory experiments
Quentin Moreno
The modern age of physics is to a large degree determined by the availability of high speed and high capacity computer systems. The use of these computing facilities for performing numerical experiments on collisionless plasmas covers now almost half a century of experience. Many problems in plasmas and in particular space plasma physics with their enormous complexity could not have been solved or even tackled without computers and numerical simulations. The latter must accompany observations and experiments in order to understand what is going on in such non-linear plasma physics. A brief discussion about numerical methods is therefore not only unavoidable but even necessary. Thus far, two kinetic numerical approaches are commonly used in the plasma physics community to study collisionless plasma processes. The Vlasov approach based on an Eulerian scheme is one of them. The code performs a direct integration of the Vlasov-Maxwell system of equations discretized on a phase-space grid. Another approach is the Particle-In-Cell method (PIC) using a Lagrangian-Eulerian approach, where the distribution function of each species is formed by a collection of computational particles (CPs), and Maxwell’s equations are solved on an Eulerian grid. Such codes can be used to excite linear plasma modes and nonlinear plasma dynamics can be followed. Our presentation is dedicated to PIC simulation code and is structured as follows. We outline the principle upon which a PIC code is based in a first part, and we summarize the numerical Yee leap-frog scheme. A second part is dedicated to present the Open Source simulation code SMILEI, where examples will be illustrate in a third part.
Sporilov, mistnot 101