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Title: Wall-plug efficiency and beam dynamics in free-electron lasers using energy recovery linacs

Journal Article · · IEEE Journal of Quantum Electronics

In a high average power free-electron laser (FEL) the wall-plug efficiency is of critical importance in determining the size, complexity, and cost of the overall system. The wall-plug efficiency for the FEL oscillator and amplifier (uniform and tapered wiggler) is strongly dependent on the energy recovery process. A theoretical model for electron beam dynamics in the energy recovery linac is derived and applied to the acceleration and deceleration of nano-Coulomb electron bunches for a tapered FEL amplifier. For the tapered amplifier, the spent electron beam exiting the wiggler consists of trapped and untrapped electrons. Decelerating these two populations using different phases of the radio-frequency wave in the recovery process enhances wall-plug efficiency. For the parameters considered here, the wall-plug efficiency for the tapered amplifier can be {approx}10% using this approach.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Organization:
DOE - OFFICE OF SCIENCE
DOE Contract Number:
DE-AC02-98CH10886
OSTI ID:
1014295
Report Number(s):
BNL-93620-2010-JA; IEJQA7; R&D Project: KBCH139; 18054; KB0202011; TRN: US1102718
Journal Information:
IEEE Journal of Quantum Electronics, Vol. 46, Issue 8; ISSN 0018-9197
Country of Publication:
United States
Language:
English