A free-electron laser in a uniform magnetic field |
| |
Authors: | S K Ride W B Colson |
| |
Institution: | (1) Johnson Space Center, NASA, 77058 Houston, TZ, USA;(2) Space Physics, Rice University, 77001 Houston, TX, USA |
| |
Abstract: | The interaction of free electrons and free electromagnetic radiation, in the presence of a uniform magnetic field, can result
in stimulated emission or absorption. We analyze the dynamics of single electrons by solving the classical, relativistic Lorentz
force equations of motion in these combined fields. An electron may gain energy from, or lose energy to, the radiation field,
depending crucially on the phase and oscillation frequency of the electron's helical motion within the superposed, circularly
polarized light wave. To first order in the radiation field strength, electrons in a monoenergetic, uniformly distributed
beam become spatially bunched, but there is no net energy change. To second order, however, the beam may experience a gain
or loss of energy, corresponding to attenuation or amplification of radiation. We compare the bunching of this laser process
to the bunching processes involved in 1) the Stanford free-electron laser and 2) the cyclotron maser, and find significant
differences in each case. Our analytic results provide a clear, simple picture of the interaction process, and can be useful
in exploring light amplification in astrophysical magnetic fields, the magnetosphere, or in laboratory devices.
Supported in part by Army Contract No. DASG 60-77-C-0083 and NASA Grant NSG-7490. |
| |
Keywords: | 41 42 55 95 |
本文献已被 SpringerLink 等数据库收录! |
|