54th shape file -thick cylinder with rounded edge, by users equations
There are 3 electrodes, all defined by users equations:
The first is the rounded edge, radius 0.05.
The second is a disc for the flat end, inner radius 1.05, outer radius 1.3, at z = 0.05.
The third is the inner wall of the thick cylinder, radius 1, from z = -1 to z = 0.
The equations for the rounded edge are self-explanatory.
The equations for the disc concentrate the segments at the inner edge.
The equations for the cylinder concentrate the segments at the edge end.
These concentrations are achieved by including an exponent n that in this example
has the value 2.
These concentrations are important because they ensure that the widths of
the segments near the edge are comparable with those of the edge.
Unfortunately this comparability will be difficult to achieve in a practical
case because the edge would usually be sharper than in the present example.
Increasing the exponent n can help, but it is still necessary to do two things
that are usually strongly discouraged.
The first is to disable the tests for nearness of segments, using
databuilder\segments\advanced options\disable check for overlapping...
The second is to disable the usual check for the thinness of triangles,
by entering a negative number (perhaps a large negative number) for the
maximum ratio of length to breadth, using
databuilder\printing error and checks\allowed reading...
Violating the usual rules in this way should not be harmful because the segments
all have the same potential and the system has axial symmetry.
A minor point -the x=y (diagonal) symmetry has not been used here, but when
it can (and therefore should) be used the angular ranges should be halved.