Local and Fundamental Mode Coupler Damping of the Transverse Wakefield in the RDDS1 Linacs

Technical Report · Wed Sep 06 04:00:00 EDT 2000

DOI:https://doi.org/10.2172/765002· OSTI ID:765002

Jones, Roger M ^[1]

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1. SLAC

In damping the wakefield generated by an electron beam traversing several thousand X-band linacs in the NLC the authors utilize a Gaussian frequency distribution of dipole modes to force the modes to deconstructively interfere, supplemented with moderate damping achieved by coupling these modes to four attached manifolds. Most of these modes are adequately damped by the manifolds. However, the modes towards the high frequency end of the lower dipole band are not adequately damped because the last few cells are, due to mechanical fabrication requirements, not coupled to the manifolds. To mitigate this problem in the present RDDS1 design, the output coupler for the accelerating mode has been designed so as to also couple out those dipole modes which reach the output coupler cell. In order to couple out both dipole mode polarizations, the output coupler has four ports. They also report on the results of a study of the benefits which can be achieved by supplementing manifold damping with local damping for a limited number of cells at the downstream end of the structure.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 765002
• Report Number(s): SLAC-PUB-8608
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
DAMPING
DESIGN
DIPOLES
ELECTRON BEAMS
LINEAR ACCELERATORS
LINEAR COLLIDERS