Angular momentum of radiation from a charge drifting along a cylindrical channel in a magnetic field

Abstract The angular momentum of radiation related to the passage of relativistic particles in a cylindrical channel is studied theoretically. To enhance the angular momentum of radiation, it is proposed to place the channel in a strong magnetic field parallel to the channel axis. The trajectories of the particles in the channel, the conditions for trapping particles in the channeling mode are investigated and equations for calculating the orbital angular momentum of radiation are obtained. It is shown that the angular momentum of radiation of a uniform beam of particles in the channel is not equal to zero only if the particles enter the channel at an angle greater than the critical angle. A significant difference between vortex radiation from a bunch of cylindrical channels (for example bunch of carbon nanotubes) from laser or undulator radiation is that the radiation beam of the latter has only one vortex axis. While the radiation from the beam of cylindrical channels has one vortex axis per each channel. Dependence of the angular momentum of radiation on the value of magnetic field and on the incident angle is studied.