47th example, accelerator tube, as used in Van der Graaf accelerators.
See xmpl3d77 for the analogous 3D simulation.
This is a simplified simulation, with a relatively small number of accelerator rings. No attempt has been made to optimise the design.
The tube has 16 rings. The overall acceleration voltage is 750kV, 50kV per ring. The particles are H2+ molecules. Their initial energy is 1640eV, which has been chosen to give approximate focusing at the end of the tube. The existence of spherical aberration can be seen.