Title :
Efficiency enhancement experimentwith a tapered undulator in a single-pass seeded fel at the NSLS SDL
Author :
Watanabe, T. ; Wang, X. ; Li, R. ; Shen, Y. ; Harder, D. ; Rakowsky, G. ; Murphy, J.B. ; Freund, H.P.
Author_Institution :
BNL, Upton
Abstract :
The experimental observation of FEL efficiency enhancement using a tapered undulator in a single-pass seeded FEL at the NSLS SDL is reported. The last 2.5 m of the 10 m NISUS undulator was linearly tapered so that the magnetic field strength at the end of the undulator was reduced by 5%. The FEL energy gain along the undulator was measured for both the tapered and un-tapered undulators. We observed that the FEL efficiency was more than doubled by applying the taper. The experimental results are compared with the numerical simulation code,GENE- SIS1.3 [1].
Keywords :
electron beams; free electron lasers; magnetic fields; particle beam bunching; wigglers; FEL energy gain; NSLS SDL; electron beam energy; electron bunch duration; magnetic field strength; multi ring structure; single-pass seeded FEL efficiency enhancement; tapered undulator; Brightness; Electron beams; Electron traps; Energy measurement; Free electron lasers; Light sources; Magnetic field measurement; Magnetic fields; Magnetic resonance; Undulators;
Conference_Titel :
Particle Accelerator Conference, 2007. PAC. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
978-1-4244-0916-7
DOI :
10.1109/PAC.2007.4441086
