Radiation energy loss of an accelerated charge in an absorbing medium

The radiation produced by an arbitrarily moving relativistic charge in an absorbing medium is considered in terms of the radiation energy loss. The energy-angular distributions of emitted photons for Cherenkov radiation, prompt bremsstrahlung, and uniform motion over finite distance (the Tamm problem) are derived. The Doppler effect in an absorbing medium for undulator-like motion is considered. The high-energy, low-angle approximation of the spectra is discussed in terms of the complex formation zone of the radiation produced by an ultra-relativistic charge in an absorbing medium.