Electromagnetic field generated by a charge moving along a helical orbit   inside a dielectric cylinder
  The electromagnetic field generated by a charged particle moving along a helical orbit inside a dielectric cylinder immersed into a homogeneous medium is investigated. Expressions are derived for the electromagnetic potentials, electric and magnetic fields in the region inside the cylinder. The parts corresponding to the radiation field are separated. The radiation intensity on the lowest azimuthal mode is studied. 
A.A. Saharian, A.S. Kotanjyan, M.L. Grigoryan