Abstract:
A possibility to measure the energy and polarization distributions of high intensity gamma-beams is considered. This possibility is based on measurements of the number of electron-pozitron pairs in such media as laser waves and single crystals. The method may be useful for future gamma-gamma and e-gamma colliders.

Abstract:
The process of the vacuum polarization energy losses of high energy cosmic rays propagating in the extragalactic space is considered. The process is due to the polarization of Cosmic Background Radiation by a moving charged particle. With the goal of the description of the process, the photon mass, refractive indices and permittivity function for low and high energy photons are found. Calculations show the rather noticeable level of the energy losses for propagating protons with the enegies more than 10^6 - 10^7 GeV. The influence of the polarization energy losses on propagation of cosmic rays is discussed.

Abstract:
Propagation of gamma-beam in the anisotropic medium is considered. The simpliest example of such a medium of the general type is a combination of the two linearly polarized monochromatic laser waves with different frequencies (dichromatic wave). The optical properties of this combination are described with the use of the permittivity tensor. The refractive indices and polarization characteristics of normal electromagnetic waves propagating in the anisotropic medium are found. The relations, describing variations of gamma-beam intensity and Stokes parameters as functions of propagation length are obtained. The influence of laser wave intensity on the propagation process are calculated. The gamma-beam intensity losses in the dichromatic wave depend on the initial circular polarization of gamma-quanta. This effect is also applied to the single crystals, which are oriented in some regions of coherent pair production. In principle, the single crystal sensitivity to a circular polarization can be used for determination of polarization of high energy (in tens GeV and more) gamma-quanta and electrons.

Abstract:
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.

Abstract:
It is shown that single crystals are sensitive to the initial circular polarization of gamma-quanta with energies in tens GeV and more. The possibility of measurement of gamma-beam polarization is discussed. The obtained results may be useful for creation of polarimeters for high energy beams of gamma-quanta.

Abstract:
The analytical description of the volume reflection of the charged ultrarelativistic particles in bent single crystals is considered. The relation describing the angle of volume reflection as a function of the transversal energy is obtained. The different angle distributions of the scattered protons in the single crystals are found. Results of calculations for 400 GeV protons scattered by the silicon single crystal are presented.

Abstract:
The equations for variation of the Stokes parameters and intensity of photons propagating in a medium, whose optical properties may be described by the permittivity tensor, are derived. Classification of different cases of photon propagation is suggested on a basis of these equations.

Abstract:
Coherent bremsstrahlung of high energy electrons moving in a three-dimensional imperfect periodic lattice consisting of a complicated system of atoms is considered. On the basis of the normalized probability density function of the distribution of atomic centers in the fundamental cell the relations describing coherent and incoherent contributions into cross sections are obtained. In particular, the cross section of coherent bremsstrahlung in complex polyatomic single crystals is found. The peculiarities of formation and possibilities of utilization of coherent processes are discussed.

Abstract:
The radiation of relativistic charged particles for the quasiperiodic motion in a transparent medium is considered. For motion of the general kind the differential probability of the process is obtained. For planar motion the spectral intensity of radiation is found. The different cases of radiation in the medium-filled undulators are studied. In particular, the influence of Cherenkov radiation on the undulator one is discussed.