Discussion on spin-flip synchrotron radiation

Quantum spin-flip transitions are of great importance in the synchrotron radiation (SR) theory. To undersand better the nature of this phenomenon, it is necessary to except from observation effects connected with charge radiation. That fact explains the choice suggested here of the spin-flip radiation model in the form of radiation of the electric neutral Dirac-Pauli particle moving in the homogeneous magnetic field. It is known that in this case the whole radiation in the quantum theory is conditioned by the spin-flip transitions. The idea is that spin-flip radiation is represented as a nonstationary process connected with spin precession. From this point of view, we have shown how to construct the solution of the classical equation of the spin precession in the Frenkel-BMT theory having the exact solution of the Dirac-Pauli equation. Thus, it is found the connection of the quantum spin-flip transitions with classical spin precession.