Speaker
Description
Beams in circular colliders exhibit complex nonlinear dynamics shaped by the interplay of different mechanisms. At interaction points (IPs) colliding beams represent an electromagnetic (EM) potential to each other which perturbs the particle trajectories. These perturbations can lead to undesired dynamical behavior of the beams resulting in emittance growth, reduction of beam lifetime and luminosty. In lepton colliders, such as the currently operating SuperKEKB and the proposed FCC-ee, synchrotron radiation in the machine arcs and at the IPs shape the dynamics and over many turns define the equilibrium emittances. Turn-by-turn modeling refers to the numerical integration of the equations of motion of the beam particles as they circulate through a sequence of EM elements (magnets, RF cavities, IPs) modeling the accelerator. This tutorial session will make use the codes WarpX and Xsuite in a turn-by-turn simulation workflow and students will use this workflow to model the convergence of a beam, initialized out of equilibrium, to the equilibrium emittances through synchrotron radiation. If time and resources permit, students will use the workflow to perform a parameter scan of the horizontal tune to map out stable working points of the machine by submitting a set of jobs to a cluster, then collecting and analyzing the data. Students will gain experience in beam dynamics, beam instabilities, simplified modeling of an accelerator and data analysis.
