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.