A synthetic pulse method for excitation of RF-accelerator structures

It is proposed to excite RF-cavity accelerator structures in a phaselocked multifrequency mode of operation. The purpose is to obtain high accelerating gradients with smaller average losses than in the conventional single-frequency operation scheme. In general the resonant frequencies are not harmonically related to each other. Assuming finite Q-values one can always find a frequency fo such that within a 3 dB bandwidth all resonances considered are at integer multiples of f0. For the gap voltage one obtains in this case a periodic pulse in the time domain with T = 1/f0. Increasing the peak gap voltage by adding (exciting) further higher modes with equal CW power on each mode (equal shout impedances assumed) results in power losses proportional to $V_{peak}$ instead of $P_{loss} ~ V_{peak}^2$ for single-frequency operation.