Quantum theory of stimulated processes in a free-electron laser in the strong-field range
Abstract
General quantum-mechanical equations are obtained for an electron in a spatially periodic magnetic field and in an electromagnetic-wave field. Limits of applicability for calculations in the lower order of perturbation theory are found. It is shown that, as applied to gain calculations, these limits are considerably broader than in the general case, due to the substantial compensation of higher-order corrections that contribute to the gain. The saturation parameter (mu) is determined, along with the asymptotic dependence of gain on mu for mu greater than unity. Spectral properties of the gain are analyzed, particularly the field-strength-dependent width and shift of the resonance maximum. For mu greater than unity, an analytical expression is obtained for the maximum (in terms of the spectrum) gain, which decreases as the -3/2 power of amplified-wave field strength.
- Publication:
-
Zhurnal Eksperimentalnoi i Teoreticheskoi Fiziki
- Pub Date:
- June 1979
- Bibcode:
- 1979ZhETF..76.1996M
- Keywords:
-
- Electron Scattering;
- Field Strength;
- Free Electrons;
- Laser Applications;
- Magnetic Fields;
- Perturbation Theory;
- Quantum Theory;
- Electromagnetic Radiation;
- Equations Of Motion;
- Integral Equations;
- Optical Resonance;
- Quantum Electrodynamics;
- Spectrum Analysis;
- Lasers and Masers