General information Data-builder topics, 3D Information on the topics in the 3D data-builder list. File names. Printing level and checks. Symmetries. Electrodes. Segments. Voltages and magnetic fields. Preliminary field information. Test planes. Setting up rays and space_charge. Tracing the rays. Automatic focussing options. Footnotes. Copyright © 1993-2023 by Frank Read. All Rights Reserved.