Transition radiation and transition scattering - Some questions regarding the theory

Cerenkov radiation is emitted by a charged particle which is in uniform, rectilinear motion in a transparent medium, if the particle speed exceeds the phase velocity of light in the medium. It is generally assumed that the medium is homogeneous and that its characteristics are time-invariant. This book is concerned with the conditions which arise if the medium is not homogeneous and (or) if its characteristics change as a function of time. In such a case, a 'transition' radiation is emitted. When the charged particle passes through a medium in which the refractive index undergoes a periodic change, the corresponding process can be called 'transition' scattering. Attention is given to the theory of transition radiation, problems regarding transition radiation, transition scattering, transition bremsstrahlung involving transition radiation under conditions of particle collisions, and the recurrence of transition radiation, scattering, and bremsstrahlung in a plasma. The corresponding processes in a vacuum in the presence of strong electromagnetic fields are also examined.