北京FEL电子束时间分辨能谱仪设计

DESIGN OF TIME-DEPENDENT ELECTRON-BEAM SPECTRA DIAGNOSTICS FOR THE BEIJING FEL

摘要: 从Wiggler出来的电子束,经过180°偏转后进人能谱和时间谱诊断系统。180°偏转段设计成既可等时又可消色散传输,等时传输是为满足对电子束微脉冲时间谱诊断,消色散是为满足电子束宏脉冲时间分辨能谱诊断。宏脉冲时间分辨能谱诊断系统由四台匹配透镜、双缝仪、扫描偏转线圈、90°对称双聚焦分析磁铁、位于焦平面的荧光靶、带有象增强器的视频摄象系统和在线计算机图象处理系统组成,其能量分辨好于1000,时间分辨好于60ns。

Abstract: After passing through the Wiggler and the 180°bend, the electron beam is transported to a time-dependent energy spectrometer. The 180°bend is designed for both achromatic and isochronous to suffice measurements of energy and temporal distributions or time-resolution of macropulses. The time-dependent energy spectra system contains four matching quadrupoles, a two-slit device, a slow-deflector sweep coil, a 90°analyzing magnet with horizontal and vertical focus, a quarts plate at the focal-plane of the magnet, a vidican TV camera with microchannel-plate intensifiers and a picture display system with a on-line micro-computer. Energy-resolution ratio of the spectrometer is large than 1000, while time resolution less than 60 ns.