Improved space charge modeling in cylindrical coordinates

Summary form only given. Many electromagnetic and charged-particle beam devices are primarily cylindrical in nature. In such cases, simulation codes employing cylindrical coordinates are extremely efficient, yielding high space/time resolution while minimizing computational costs. However, it has long been known that the curvature of (r, z) and (r, Φ, z) coordinates requires adjustment of solution coefficients and particle/current weights as functions of distance from the axis to reduce effects of numerical noise. Recent progress on charge interpolation¹ and solution coefficients² has provided a consistent methodology for improved simulation in cylindrical coordinates. In this paper, the improved techniques will be presented, along with their implementation in a widely used 2D particle-in-cell code, XOOPIC³, and comparisons to standard solution methods. Comparisons are also made with finite element models using the BOA⁴ code.