Orbital angular momentum of channeling radiation from relativistic electrons in thin Si crystal

We propose to use channeling radiation (CR) from relativistic electrons as a source of high energy twisted photons in the MeV range. We calculate numerically the orbital angular momentum (OAM) of radiation produced by electrons with the energies 155÷2500 MeV for the axial and planar channeling in the thin Si crystal. We obtain that the average OAM of CR in this case is approximately 1÷6ħ per photon with the photon energies about 1÷2 MeV.