Electron beam acceleration by Compton scattering of extraordinary waves

Acceleration and heating of a high-energy or relativistic electron beam due to Compton scattering induced by nonlinear Landau damping of almost perpendicularly propagating extraordinary waves are investigated theoretically based on kinetic wave equations and transport equations derived from Vlasov-Maxwell equations. The numerical analysis of nonlinear wave-particle coupling coefficients in these equations has shown that the electron beam can be accelerated efficiently to the phase velocity of the beat wave near the speed of light by Compton scattering of two extraordinary waves with almost the same frequencies. The acceleration or deceleration of the electron beam occurs in accordance with whether the phase velocity of the beat wave is slightly larger or smaller than the velocity of the electron beam, respectively. For the frequencies of two waves lower than the upper-hybrid frequency (omega less than or similar to omega(h)), or for those exceeding the right-hand cutoff frequency (omega greater than or similar to omega(R)), the acceleration and deceleration of the electron beam become significantly strong. (C) 1999 American Institute of Physics. [S1070-664X(99)01511-6].