Theory of radiation of charged particles channeled in a crystal

Abstract

Abstract The theory of a new effect is developed — spontaneous radiation of γ‐quanta in channeling relativistic particles. The radiation characteristics are different from the presently known types of radiation sources. At energies of the order of 1 GeV the radiation is characterized by wavelength ⪅ 10 −3 Å. The radiation intensity is about 6 to 9 orders of magnitude higher than obtained from modern synchrotrons. Its monochromaticity is considerably better than bremsstrahlung or synchrotron radiation. The radiation is fairly well polarized. In the quantum treatment, the radiation is caused by transitions between levels, which are formed in channeling in the fields of atomic planes and rows. A classical and quantum calculation of the radiation intensity is presented. At a current of about 100 μA and a target thickness of ≈︁ 1000 μm, about 10 18 to 10 19 quanta/s are radiated. The spectral density of the radiation is considerably higher than that of any known kind of radiation. It is suggested that the radiation might be used to influence selectively nuclear transitions and to produce a γ‐laser. This radiation can be used to study the crystal lattice potentials, measure the particle energy, and so on. Dispersion is studied. The possibility of enhancing the induced radiation is shown. A number of studies on light channeled particles are analysed.