Calculation of asymptotic and RMS kicks due to higher order modes in the 3.9-GHz cavity

[摘要] FLASH plans to use a 'third harmonic' (3.9 GHz) superconducting cavity to compensate nonlinear distortions of the longitudinal phase space due to the sinusoidal curvature of the cavity voltage of the TESLA 1.3 GHz cavities. Higher order modes (HOMs) in the 3.9 GHz have a significant impact on the dynamics of the electron bunches in a long bunch train. Kicks due to dipole modes can be enhanced along the bunch train depending on the frequency and Q-value of the modes. The enhancement factor for a constant beam offset with respect to the cavity has been calculated. A simple Monte Carlo model of these effects, allowing for scatter in HOM frequencies due to manufacturing variances, has also been implemented and results for both FLASH and for an XFEL-like configuration are presented.

[发布日期] 2008-03-01

[学科分类] 核物理和高能物理

[关键词] CAVITIES;CONFIGURATION;DIPOLES;ELECTRONS;MANUFACTURING;PHASE SPACE;Q-VALUE Accelerators