Multibunch beam break-up in detuned structures [next-generation linacs]

A key problem in next-generation linear collider designs utilizing multibunching is the control of multibunch beam break-up. One method of controlling the break-up is detuning, i.e., varying the frequency of the transverse deflecting modes by varying the cell dimensions within the accelerating structures. In this case, the beam break-up is sensitive to the resonances between the bunch frequency and some of the deflecting mode frequencies. It is also sensitive to errors in the fabrication and alignment of the accelerating structures. We examine these effects in the context of the SLAC NLC design