The resonant theory of longitudinal emittance blow-up by phase-modulated high harmonic cavities

We consider some new aspects of controlled bunch dilution theory. The dependence of the blow-up rate on the high frequency cavity (HFC) parameters is theoretically accounted for. We found that the dilution rate has a resonant dependence on phase modulation frequency. In addition, it is strongly dependent on the phase modulation amplitude and the phase of the HFC voltage relative to the fundamental. All our theoretical conclusions have been confirmed by numerical simulation. We demonstrate how to affect different parts of the bunch and modify the particle distribution. (author) 9 refs., 5 figs