What geometries can be modeled with the 2D programs?

The 2D programs can model two types of geometry:

1. Two Dimensional (2D)

This mode is used when the real geometry is long enough in one direction that a contour plot of relevant physical properties (voltage, fields, etc.) would lie on a plane. This is illustrated below.

In this case, the 2D program works with a planar cross-section of the geometry.

2. Rotational Symmetric (RS) - aka "Axisymmetry" or "Azimuthal Symmetry"

This mode is used when the real geometry could be created by sweeping a cross section of the geometry around a central axis. This is illustrated below.

In this mode, the 2D program works with the planar cross-section w hich would be rotated to create the true geometry.

Note that while 2D mode is always an approximation based on ignoring end effects, if a geometry is truly RS, then the RS mode provides the full 3D answer.