Large Long-time behaviour of numerical integrators for charged particle dynamics

The Boris algorithm is the most popular time integrator for charged particle motion in electric and magnetic force fields. It is a symmetric one-step method, and it preserves the phase volume exactly. However, it is not symplectic. Nevertheless, numerical experiments confirm an excellent long-time near energy preservation of the system. In this talk we present a multistep extension of the Boris algorithm, which is explicit, symmetric, and has arbitrarily high order. Near preservation of energy and momentum for the underlying one-step method, and the boundedness of parasitic solution components are proved. A rigorous proof for the excellent near energy preservation of the Boris algorithm is still missing. (We thank Martin Gander for drawing our attention to this problem.)Non UBCUnreviewedAuthor affiliation: University of GenevaFacult