Transition radiation: scientific implications and applications in high-energy physics

In their pioneering work on transition radiation, Ginzburg and Frank showed for the first time that а charge may radiate electromagnetic waves not only because of its accelerated motion but also because of time variation of the phase velocity of electromagnetic waves in the ambient medium. This result is of very general importance for physics. For example, а charge at rest can radiate in а nonstationary medium. Transition radiation is widely used in high-energy particle detectors, mainly for identification of ultrarelativistic electrons in accelerator and collider experiments.