Interplay of space charge, intrabeam scattering, and synchrotron radiation in the Compact Linear Collider damping rings

Abstract

Future ultralow emittance rings for $e^{-}/e^{+}$ colliders require extremely high beam brightness and can thus be limited by collective effects. In this paper, the interplay of effects such as synchrotron radiation, intrabeam scattering (IBS), and space charge in the vicinity of excited betatron resonances is assessed. In this respect, two algorithms were developed to simulate IBS and synchrotron radiation effects and integrated in the pyorbit tracking code, to be combined with its widely used space charge module. The impact of these effects on the achievable beam parameters of the Compact Linear Collider (CLIC) damping rings was studied, showing that synchrotron radiation damping mitigates the adverse effects of IBS and space charge induced resonance crossing. The studies include also a full dynamic simulation of the CLIC damping ring cycle starting from the injection beam parameters. It is demonstrated that a careful working point choice is necessary, in order to accommodate the transition from detuning induced by lattice nonlinearities to space-charge dominated detuning and thereby avoid excessive losses and emittance growth generated in the vicinity of strong resonances.