Title :
Radiation by a modulated sheet electron beam propagating parallel to a reflection grating under a finite magnetic field
Author :
Yasumoto, Kiyotoshi ; Tanaka, Toshiyuki
Author_Institution :
Dept. of Comput. Sci. & Commun. Eng., Kyushu Univ., Fukuoka, Japan
Abstract :
The authors investigate two-dimensional radiation from a modulated sheet electron beam propagating parallel to a reflection grating under the influence of an externally applied magnetic field. From the wave-theoretic viewpoint, the spontaneous emission can be interpreted as the radiative leakage of the space-charge waves associated with the electron beam. The analysis is reduced to the determination of the complex eigen wavenumber of the space-charge waves perturbed by the presence of the periodic structure. The set of Maxwell equations and relativistic hydrodynamic equations for cold electrons is solved using a perturbation approach based on multiple-space scales. The transport equations governing the radiative leakage of the space-charge waves are systematically derived. Numerical results on the leakage coefficients and the phase change due to the leakage that depend on the applied magnetic field are presented.<>
Keywords :
diffraction gratings; electron beams; magnetic fields; modulation; Maxwell equations; cold electrons; complex eigen wavenumber; finite magnetic field; leakage coefficients; modulated sheet electron beam; multiple-space scales; perturbation approach; phase change; radiative leakage; reflection grating; relativistic hydrodynamic equations; space-charge waves; spontaneous emission; transport equations; two-dimensional radiation; wave theory; Electron beams; Gratings; Magnetic analysis; Magnetic fields; Magnetic modulators; Maxwell equations; Optical modulation; Optical reflection; Periodic structures; Spontaneous emission;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1989. AP-S. Digest
Conference_Location :
San Jose, CA, USA
DOI :
10.1109/APS.1989.134597