Paper detail

Gamma-quanta propagation in single crystals

Propagation of gamma-quanta in the single crystals, oriented in a region of the coherent pair production is considered. The qualitative description of the process is also discussed. The theory of gamma-quanta propagation in the anisotropic medium is illustrated by the help of the particular calculations of such a process in silicon single crystals. It is shown that the single crystals are sensitive to the initial circular polarization of gamma-beam despite the fact that the cross section of absorption is independent of it. The reason is that the normal electromagnetic waves (an eigenfunctions of the problem) are elliptically polarized. The speeds of absorption and motion of both the normal waves are different and as a result the process of gamma-quanta propagation depend on the initial polarization state. The calculated value of asymmetry is about 20% for 25 GeV gamma-quanta propagating in 100 cm silicon single crystal. The obtained results are useful in creating of polarimeters for high energy electrons and gamma-quanta.