Accession Number : ADA194525

Title :   Guided Radiation Beams in Free Electron Lasers.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Ting, A ; Sprangle, P ; Hafizi, B ; Tang, C M

PDF Url : ADA194525

Report Date : 19 May 1988

Pagination or Media Count : 51

Abstract : In a free electron laser (FEL), the radiation field, wiggler field and electron beam resonantly couple and modify the refractive index in the vicinity of the electron beam, such that the radiation beam will tend to focus upon the electron beam. From the radiation envelope equation derived from the source dependent expansion (SDE) method of solving the 3-D wave equation in FELs, conditions and parameters necessary to achieve guided radiation beams (constant radius) in the Compton exponential gain regime are obtained for FELs driven by either induction linacs or rf linacs with various transverse profiles of the electron beam. From the efficiency of the guided radiation beam, the trapping potential of the ponderomotive potential prior to saturation and the required beam quality of the electron beam can be obtained. The wiggler field could be tapered to further increase the operating efficiency. The possibility of bending or steering radiation beams in FELs is discussed and a condition necessary for radiation guiding along a curved electron beam orbit is obtained. Keywords: Free electron lasers; Guided radiation.

Descriptors :   *FREE ELECTRON LASERS, BEAMS(RADIATION), CURVATURE, ELECTRON BEAMS, ENVELOPE(SPACE), EQUATIONS, EXPANSION, ORBITS, PROFILES, RADIATION, RADIUS(MEASURE), REFRACTIVE INDEX, SOURCES, STEERING, TRANSVERSE

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE