Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1832158 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2006 | 12 Pages |
Abstract
With HERA as a model, the collective (coherent) beam-beam instability in the case of weak-strong or very unsymmetrical beam-beam interactions was studied with a self-consistent beam-beam simulation by using the particle-in-cell method. It was found that when the beam-beam parameter of the weak lepton beam exceeds a threshold that corresponds to an overlap of the weak beam with low-order single-particle beam-beam resonances, the onset of the coherent beam-beam instability results in a significant emittance growth of the strong proton beam. After the onset of the coherent beam-beam instability, both the beams could develop a spontaneous coherent oscillation and the quasi-equilibrium distribution of the lepton beam deviates from a Gaussian distribution with a formation of a beam halo. The collective instability of weak-strong beam-beam interactions has been confirmed in a beam experiment on HERA. The phenomena observed in the experiment qualitatively agree with the numerical prediction.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
J. Shi, L. Jin,