Two-dimensional theory and simulation of free electron lasers

Conference · Thu Jan 01 00:00:00 EST 1981

OSTI ID:6465613

Kwan, T J.T.; Cary, J R

Two-dimensional homogeneous theory of free-electron lasers with a wiggler magnetic field of constant wavelength is formulated. It has been found from the theory that waves propagating obliquely with respect to the electron beam are always unstable with appreciable growth rates; therefore, mode competition among the on-axis and off-axis modes is an important consideration in the design of the free-electron laser. Furthermore, electromagnetic waves with group velocities opposite to the direction of electron beam propagation are absolutely unstable if k/sub o/v/sub o/ > ..omega../sub pe/(1/..gamma../sup 3/2/ + 1/..gamma../sup 1/2/). Due to strong nonlinear saturation levels of the low-frequency absolute instability, the dynamics of the electron beam and the generation of the high-frequency electromagnetic radiation can be severely affected. Two-dimensional particle simulations show that the efficiency of generation of the on-axis high-frequency electromagnetic wave decreases significantly due to instability of the off-axis modes. In addition, complete disruption of the electron beam and laser oscillation due to the onset of the absolute instability have been observed in simulations.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6465613
• Report Number(s): LA-UR-81-1936; CONF-810620-7; ON: DE81025365; TRN: 81-014125
• Resource Relation: Conference: 4. international topical conference on high-power electron and ion-beam research and technology, Palaiseau, France, 29 Jun 1981
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FREE ELECTRON LASERS
TWO-DIMENSIONAL CALCULATIONS
ABSOLUTE INSTABILITIES
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
INSTABILITY GROWTH RATES
BEAMS
INSTABILITY
LASERS
LEPTON BEAMS
PARTICLE BEAMS
PLASMA INSTABILITY
RADIATIONS
420300* - Engineering- Lasers- (-1989)
700208 - Fusion Power Plant Technology- Inertial Confinement Technology