Alternative optics design: nonlinear collimation system

The collimation system of a Linear Collider must serve multiple purposes and fulfill a number of constraints. In particular, we require that the collimation system should sustain the impact of off-energy bunches and have a large chromatic bandwidth, in addition to ensuring a high collimation efficiency and tolerable wake fields. We describe the design of a nonlinear energy collimation system for CLIC at 3 TeV, in which skew sextupoles are used to blow up the vertical beam size at the spoiler, so as to guarantee collimator survival in case of beam impact. Its properties, like chromatic bandwidth and collimation survival, are evaluated and compared with those of the baseline linear collimation system.