Luminosity studies in a traveling waist regime in the Compact Linear Collider

Abstract

The final focus system of the Compact Linear Collider (CLIC) features a crab cavity just before the final quadrupole doublet to ensure head-on collisions at the interaction point. A decrease in the expected luminosity with respect to the case without crossing angle has been recently observed in simulations for the CLIC baseline configuration. This effect is explained from the aberrations induced due to a z-dependent off-center horizontal orbit in the final focus sextupoles produced by the crab cavity. Three options to recover from this loss are explored. The effect of the longitudinal E-z correlation of the incoming beam from the linac is taken into account and its effect on the expected luminosity is evaluated.