  A Lorentz invariant formalism for quasi-classical description of
electromagnetic radiation from a neutral spin 1/2 particle with an anomalous
magnetic moment moving in an external electromagnetic field is developed. In
the high symmetry fields, for which analytical solutions to the
Bargmann--Michel--Telegdi equation are known, the so called self-polarization
axes, i. e. directions of preferred polarization of particles in the radiation
process, are found. Expressions for the radiative transition probability and
spectral-angular distribution of the radiation emitted by a polarized particle
are obtained in the fields under consideration.
