7 research outputs found
A high-order Boris integrator
This work introduces the high-order Boris-SDC method for integrating the equations of motion for electrically charged particles in electric and magnetic fields. Boris-SDC relies on a combination of the Boris-integrator with spectral deferred corrections (SDC). SDC can be considered as preconditioned Picard iteration to compute the stages of a collocation method. In this interpretation, inverting the preconditioner corresponds to a sweep with a low-order method. In Boris-SDC, the Boris method, a second-order Lorentz force integrator based on velocity-Verlet, is used as a sweeper/preconditioner. The presented method provides a generic way to extend the classical Boris integrator, which is widely used in essentially all particle-based plasma physics simulations involving magnetic fields, to a high-order method. Stability, convergence order and conservation properties of the method are demonstrated for different simulation setups. Boris-SDC reproduces the expected high order of convergence for a single particle and for the center-of-mass of a particle cloud in a Penning trap and shows good long-term energy stability
PIC methods in astrophysics: Simulations of relativistic jets and kinetic physics in astrophysical systems
The Particle-In-Cell (PIC) method has been developed by Oscar Buneman,
Charles Birdsall, Roger W. Hockney, and John Dawson in the 1950s and, with the
advances of computing power, has been further developed for several fields such
as astrophysical, magnetospheric as well as solar plasmas and recently also for
atmospheric and laser-plasma physics. Currently more than 15 semi-public PIC
codes are available which we discuss in this review. Its applications have
grown extensively with increasing computing power available on high performance
computing facilities around the world. These systems allow the study of various
topics of astrophysical plasmas, such as magnetic reconnection, pulsars and
black hole magnetosphere, non-relativistic and relativistic shocks,
relativistic jets, and laser-plasma physics. We review a plethora of
astrophysical phenomena such as relativistic jets, instabilities, magnetic
reconnection, pulsars, as well as PIC simulations of laser-plasma physics
(until 2021) emphasizing the physics involved in the simulations. Finally, we
give an outlook of the future simulations of jets associated to neutron stars,
black holes and their merging and discuss the future of PIC simulations in the
light of petascale and exascale computing.Comment: 117 pages, 44 figures, Invited review article for Living Reviews in
Computational Astrophysics, comments are welcomed, Living Reviews in
Computational Astrophysics, submitted, 2020, the revised version resubmitted
in December 2020, the second revised revision resubmitted in April, 2021,
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