Synchrotron radiation spectrum for a relativistic plasma column

The synchrotron radiation spectrum is calculated for a relativistic nonneutral plasma column that rotates about an axis of symmetry aligned parallel to a uniform applied magnetic field B0e/subz/. The applied magnetic field provides radial confinement of the electrons, and the electron density is assumed sufficiently low so that equilibrium self-fields have a negligible effect on the particle trajectories (ω2/subp//ω2/subc/ very-much-less-than1, where ω/subp/ is the electron plasma frequency and ω/subc/ is the electron cyclotron frequency). The analysis is carried out for the general class of radially confined equilibria described by equilibrium distribution functions of the form f0/sube/(x,p) =F (H) G (P/sub theta/) delta (p/subz/), where H is the energy, P/sub theta/ is the canonical angular momentum, and p/subz/ is the axial momentum. The detailed form of the emission spectrum I/subl/(ω) exhibits a sensitive dependence on the choice of distribution functions F (H) and G (P/sub theta/). The characteristics of the emission spectra for hollow electron layers are quite different from the emission spectra obtained when the electron density is peaked on axis. Since the influence of equilibrium self-fields on the particle trajectories is neglected in the present analysis, the results can also be applied to the synchrotron emission from rotating neutral plasma columns in which there is over-all charge neutrality