Figure 1

Illustrations to show the effect of chicanes (top) and doglegs (bottom) on the longitudinal phase space profiles of chirped bunches (orange). Plots show energy E against position z. In a chicane, (a) and (b), higher energy particles take a shorter path (dash) through the magnets than lower energy particles (dot) causing the bunch to shear forward i.e. the high energy particles move forward with respect to the bunch centre. A bunch with an initial positive chirp, as in (a) and (c), is lengthened by a chicane (a) or shortened by a dogleg (c). A bunch with an initial negative chirp, as in (b) and (d), is shortened by a chicane (b) or lengthened by a dogleg (d). As the magnitude of \(R_{56}\) is typically larger in a chicane than in a dogleg, a chicane will have a more pronounced effect on the bunch chirp.