Periodic Poisson Solver for Particle Tracking

TL;DR

This paper introduces an efficient method to solve the 3D Poisson problem for periodic sources, enabling accurate space charge calculations in beam physics with applications to laser-modulated beams.

Contribution

A novel periodic Poisson solver using a particle mesh approach with Green's function extension, optimized for periodic and pseudo-periodic structures in beam physics.

Findings

Numerically efficient solution for periodic Poisson problems.

Applicable to small period lengths relative to source dimensions.

Demonstrated use cases in laser modulated beams.

Abstract

A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics, this approach allows to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudo-periodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.