Energy loss of relativistic particles in solids

The theory of bremsstrahlung from relativistic particles as function of impact parameter is developed on the basis of the virtual photon method using the Moliere atomic potential. The contribution to the particle energy loss by collisions is calculated by means of the quantum dielectric formalism. The channeled‐to‐random energy loss ratio is calculated for both, light and heavy particles. For the hyperchanneled, ultrarelativistic positrons it is a value of the order of 10 −2 . For heavy particles the ratio is of the order of 0.5 to 0.2. On the contrary for channeled electrons there is an enhancement of the average energy loss as compared with the random case. The contributions of transition bremsstrahlung and Kumakhov radiation are discussed, too.