Longitudinal electrode voltage distribution on a 4-rod RFQ simulation model

For a proper working RFQ with minimized particle losses, a constant longitudinal voltage distribution on the electrodes is needed. This assures a sufficient compensation of the beam space change. The local electrode voltage and its change is mainly given by the varying aperture of the quadrupole and in consequence the changing local capacity. The simulation of the RFQ model with modulated electrodes is a very complex thread. An example for such a model will be given here.