Types of 3D electrodes

This note deals with:

3D Electrode types

Truncation in presence of symmetry planes

Related notes are:

How to choose the segment subdivisions.

Replacement of electrodes by sheets of charge

Dielectric materials

Avoiding touching of electrodes of different potential

Avoid segments of very different length being close together

Viewing electrodes

3D Electrode types

16 types of whole or part electrodes are available (the last 3 of which are of specialised interest).

The whole electrodes are:

evenly-divided disc electrode.

These whole electrodes are subdivided by the program into segments that are either flat triangles or flat rectangles.

The most basic triangles or rectangles are:

simple flat rectangle in x, y or z plane.

Other basic triangles or rectangles are:

triangle that lies on a spherical surface.

triangle that lies on a cylindrical surface.

triangle that lies on a conical surface.

rectangle that is on a cylindrical surface.

rectangle that is on an elliptical cylindrical surface.

The extra 3 basic triangles of specialised interest are:

end conical or cylindrical triangle.

Examples of all the different types of triangles are given in shap3d28.dat.

Other shapes of electrodes can also be created, using those in some of the 'shape' data files.

Other shapes can be generated by an external program. Compiled versions are supplied with the package.

(1) Program 12: can be used to generate the segments of a hyperbolic surface.

(2) Programs toroidal and torus can be used to generate the segments of a toroidal surface or a torus.

More importantly, users can use their own equations to produce a very wide range of shapes.

All these electrodes (except those generated by users equations) can be scaled and/or shifted and/or reflected and/or rotated. For example, this allows dimensions to be entered initially as inches and then converted to mm, or for an electrode to be initially oriented along the x, y or z axis and then rotated.

Truncation in presence of symmetry planes

There is no need to worry about any planes of reflection symmetry when entering information on whole electrodes. The program will test for consistency with those planes and will remove the unnecessary parts of the electrodes (and this will be done before the subdivision into the more basic shapes, see the note on subdivision).

But you do need to think about any planes of reflection symmetry when entering information on basic triangles and rectangles. These shapes should be entered only in the sub-volume that will fill all space after reflections (eg only in the sub-volume x and y greater than 0 if x = 0 and y = 0 are reflection planes).

There is also an option, in /contours/potentials/segments, to output detailed information on segment coordinates and charges.

For users who are editing or constructing an 'input data file' without the use of the data-builder -that is, pre-processor:

But Manual editing is certainly not recommended -it is a relic from the time when the databuilder was not available All users are strongly encouraged to use the databuilder, which always gives the correct formats and which has many options for which the formats are not described or easily deduced.

Each type of electrode is denoted by 3 letters which should be entered at the beginning of the line:

'sph' for sphere

'con' for cone

'cyl' for cylinder

'dis' for disc

'edi' for evenly-divided disc

'tri' for simple triangle

'rec' for simple rectangle

'rex' for simple rectangle that lies in a plane x = const.

'rey' for simple rectangle that lies in a plane y = const.

'rez' for simple rectangle that lies in a plane z = const.

'str' for spherical triangle

'ctr' for cylindrical triangle

'ctr' for conical triangle

'cre' for cylindrical rectangle

'ecr' for elliptical cylindrical rectangle

'est' for end spherical triangle

'ect' for end cylindrical or conical triangle

'edt' for end disc triangle.

A comment can be added from space 30 onwards.

The list of electrode is terminated in the data file with a line that starts with 'end', such as:

end of electrodes