[en] The present status of the Yerevan synchrotron and the program of its modernization and development are considered. Different versions of the long-term program of development of the Yerevan electron-photon complex is discussed

[en] The problem of interaction of radiation having arbitrary polarization and intensity with 1/2-1/2 and 1-0 resonant systems was solved. Exact expressions for the vectors of orientation of lower and upper states of the 1/2-1/2 system and for the vector of orientation and tensor of alignment of the 1-0 system in the field of elliptically polarized radiation are obtained. The influence of disorientating atomic collisions on the process of optical pumping was also studied. 10 refs

[en] The X-ray transition radiation and Cherenkov radiation in an inverse medium are investigated. The spectral distribution of energy as well as the full energy and photon number of these radiations are obtained. It is shown that the Cherenkov radiation can be used to create the new counters for identification of elementary particles with very high energies. This radiation can serve also as an intensive source of hard photons. 4 refs

[en] The problem of excitation of wake waves in plasma by a succession of charged particle bunches is considered in the linear approximation. The case of resonant amplification of the wake field taking place for definite relations between the bunch parameters is analyzed. 11 refs

[en] An analysis of quantum fluctuations of light for the process of intracavity two-photon absorption from two coherent modes of radiation field with different frequencies in a non saturating absorber is presented. Effects of squeezing of quantum fluctuations intensities of two anticorrelated modes at the cavity output below the corresponding vacuum and coherent levels of fluctuations are found. 27 refs

[en] In the positive P-representation the joint fluctuations of photon numbers and phases were investigated numerically for intracavity third harmonic generation. The third harmonic at the right from the bifurcation point of the optical system is most probably to register at two states with the same probabilities (superposition state). The oscillation time of the system between these states has the same order of magnitude with the photon lifetime in cavity. In the joint distribution function of fundamental mode phases and third harmonic there is a dip, which size increases with removing of the system to the right from the bifurcation point. 9 refs

[en] The Green function of classical electromagnetic field is derived for a medium consisting of an arbitrary number of coaxial cylindrical layers. As an application of the general formula the radiation intensity from a charged particle, rotating around the cylinder surrounded by a homogeneous medium, is calculated. 9 refs

[en] In samples with the Cu₁-x-yBi_xPb_ySr₂CaCu₂O_z composition obtained by solid state synthesis method a superconducting phase with a critical temperature T_c∼85K is discovered. Superconductivity is observed in the samples rapidly cooled down from synthesis temperatures. It is supposed that superconductivity is caused by the presence of the (Bi,Pb)Sr₂CaCu₂O₂ compound. 7 refs

[en] Results of an investigation of pyroelectric properties of α-LiI0₃ crystals in the temperature range from 170 to 420 K are reported. A comparison with pyroelectric properties of ADTGS, LiTaO₃ and LiNbO₃ crystals has been made. The influence of entrapped mother solution on the pyroelectric properties and electrical conductance of α-LiI0₃ is shown. 7 refs

[en] Accelerator driven subcritical power complexes are considered containing fast booster reactor and main reactor on thermal neutrons. It is shown that very high characteristics of such systems are available at contemporary level of the accelerator technique with the use of existing reactor units.12 refs