Resonant Collimation for Future Linear Colliders

Abstract

We present a scheme for collimating large amplitude particles in the main linacs of a linear collider, by adding octupoles to the FODO lattice of the linac. The requirements on downstream collimation can in this way be greatly reduced or perhaps even eliminated. An analytic estimate of the amplitude at which particles are lost is made by calculating the separatrix of the fourth order resonance, and is in good agreement with the results of simulations. Simulations of particle distributions in the beam core and halo are presnted, as well as alignment tolerances for the octupoles. Presented at 16th ICFA Beam Dynamics Workshop on Nonlinear and Collective Phenomena in Beam Physics, Arcidosso, Italy, September 1-5, 1998 Work supported by Department of Energy contract DE{AC03{76SF00515. Nonlinear Resonant Collimation for Future Linear Colliders P.Emma, R.Helm, Y.Nosochkov, R.Pitthan, T.Raubenheimer, K.Thompson, F.Zimmermann Stanford Linear Accelerator Center, MS 26, P.O.Box 4349, Stanford, CA 94309, USA Abstract. We present a scheme for collimating large amplitude particles in the main linacs of a linear collider, by adding octupoles to the FODO lattice of the linac. With this scheme the requirements on downstream collimation can be greatly reduced or perhaps even eliminated. An analytic estimate of the amplitude at which particles are lost is made by calculating the separatrix of the fourth order resonance, and is in good agreement with the results of simulations. Simulations of particle distributions in the beam core and halo are presented, as well as alignment tolerances for the octupoles. We present a scheme for collimating large amplitude particles in the main linacs of a linear collider, by adding octupoles to the FODO lattice of the linac. With this scheme the requirements on downstream collimation can be greatly reduced or perhaps even eliminated. An analytic estimate of the amplitude at which particles are lost is made by calculating the separatrix of the fourth order resonance, and is in good agreement with the results of simulations. Simulations of particle distributions in the beam core and halo are presented, as well as alignment tolerances for the octupoles.

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Cite this paper

@inproceedings{Helm1998ResonantCF, title={Resonant Collimation for Future Linear Colliders}, author={Raimund Helm and Y . Nosochkov and Rainer Pitthan and T . O . Raubenheimer and Katherine Thompson}, year={1998} }