Radiation from a charge in circular motion
under constructionPrinciples of Electrodynamics, Melvin Schwartz, 1987, p. 222-223:
. . . it is useful to examine in detail the radiation pattern due to a charge moving in a circle, with v << c. In Fig. 6-4 we sketch a coordinate system relative to the center of the circular path taken by the charge.
The charge moves counterclockwise as viewed from the +z direction. As we observe the charge from the various directions, we see the acceleration vector carrying out its periodic motion with the rotational frequency of the particle. From along the +z axis, the acceleration vector always appears to have the same length and rotates about in a circle. Hence we have circularly polarized light going out along the positive and negative z directions. . . .
In the xy plane the radiation is plane polarized with the electric vector always lying in this plane.
Fig. 6-4 A charged particle moving in a circle gives rise to circularly polarized radiation along the axis of its motion and linearly polarized radiation at right angles to this axis. In other directions the “light” is elliptically polarized.
Gamma rays can be circularly polarized:
http://www.stonybrook.edu/icfa2001/Papers/w5-3.pdf
http://www.nature.com/nature/journal/v168/n4279/abs/168782a0.html
http://iopscience.iop.org/1674-1137/33/8/018
Rotation of an electric charge produces electromagnetic radiation. What would rotation of a magnetic charge produce? Magnetism is dipolar, instead of monopolar like electric charges. Such a charge would have to be "synthetically" or "equivalently" produced. I cannot find any research on this topic. But there are reports of strange effects from rotating magnets in a specially configured apparatus:
http://www.overunity.com/index.php?topic=1194.0;wap2
http://www.overunity.com/index.php?topic=1194.5;wap2