Spectrum of Radiation of a Bunch of Positrons Channeled in Densely Packed Nanotubes

Abstract

The problem of the radiation of a relativistic bunch of positrons channeled in densely packed nanotubes was solved. A model parabolic potential was used for the average nanotube field. The channeled positrons oscillate with the same frequency, but with different amplitudes equal to the distance from the point of entry of the positron in the nanotube to its axis. The polarization of the nanotube environment results in the appearance of a lower energy threshold for the formation of radiation. The boundaries of the frequency interval of radiation also depend on the amplitude of the oscillating positron. For the first time an analytical expression for the spectrum of the total radiation is obtained in the dipole approximation. At a zero angle, both hard (gamma) and soft (X-ray) photons are generated. Directed photon beams have important practical applications.