Title :
Diffusion mechanism of particle beams in the presence of phase modulation in double RF systems
Author :
Ball, M. ; Budnick, J. ; Chu, C.M. ; Fung, K.M. ; Hamilton, B. ; Jeon, D. ; Kang, X. ; Kiang, L.L. ; Lee, S.Y. ; Pei, A. ; Sloan, T. ; Ng, K.Y.
Author_Institution :
Indiana Univ., Bloomington, IN, USA
Abstract :
The particle diffusion mechanism due to phase modulation on one of the RF cavities in a double RF system is studied. We find that the Einstein relation is satisfied if there is a global chaos in the phase space. On the other hand, the existence of dominant parametric resonances forces the particles streaming along the separatrix, which may result in an anomalous diffusion process. The particle tracking simulations based on the Hamiltonian for the double RF system is employed to reveal the essential diffusion mechanism. Also for the first time, a coherent octupole mode has been observed in the bunch beam excitation. The phase space evolution of the octupole mode is displayed
Keywords :
accelerator RF systems; accelerator cavities; chaos; particle beam bunching; particle beams; phase modulation; Einstein relation; RF cavities; anomalous diffusion; bunch beam excitation; coherent octupole mode; dominant parametric resonances; double RF systems; global chaos; octupole mode; particle beams; particle diffusion mechanism; particle tracking simulations; phase modulation; phase space evolution; Chaos; Diffusion processes; Particle beams; Particle tracking; Phase modulation; Physics; Radio frequency; Stochastic processes; Synchrotrons; Voltage;
Conference_Titel :
Particle Accelerator Conference, 1999. Proceedings of the 1999
Conference_Location :
New York, NY
Print_ISBN :
0-7803-5573-3
DOI :
10.1109/PAC.1999.794162
