Title :
Phase slip in an undulator with pole and BPM errors
Author_Institution :
Linear Accel. Center, Stanford Univ., CA, USA
Abstract :
A statistical analysis of a corrected electron trajectory through a planar FEL undulator is used to predict the optimal beam position monitor (BPM) spacing. The undulator is composed of modular sections, each containing many dipoles with random field and roll angle errors. Located between each section are inaccurate BPMs, steering correctors, and possibly quadrupole magnets. An analytical formula for electron-to-photon phase errors is derived and used to estimate the best BPM spacing. The results are applied to the LCLS FEL undulator, which has demanding requirements on electron trajectory straightness
Keywords :
electron optics; free electron lasers; wigglers; FEL undulator; beam position monitor spacing; electron trajectory; electron-to-photon phase errors; phase slip; pole errors; statistical analysis; Amplitude estimation; Electron beams; Linear accelerators; Magnetic analysis; Magnets; Monitoring; Phase estimation; Statistical analysis; Trajectory; Undulators;
Conference_Titel :
Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-7191-7
DOI :
10.1109/PAC.2001.987892
