Table of contents

The review is devoted to presentation of experimental and some theoretical results of the study of ionization processes in collisions of atomic particles of low energy. One of the main purposes of the review is to attempt to systematize the numerous results and methods of the experimental study of processes of formation of charged particles in collisions with energies below the characteristic ionization potentials (socalled chemi-ionization processes). The main attention in the review is devoted to studies carried out in recent years on the dynamics, energetics, and the electronic mechanism of processes involving particles in reliably identified states. Detailed discussions are given of questions of chemi-ionization with dissipation of electronically excited particles (Penning ionization), processes with transfer of an electron, and associative ionization of atomic particles of thermal energies. In conclusion some promising features of further studies of chemionization processes are discussed.

This review is devoted to a systematic exposition of theoretical and experimental results related to the physics of cylindrical magnetic domains (bubbles). The stability problem is discussed for an individual cylindrical domain and for a lattice of such domains, with allowance for the effect of the coercivity on the stability and dynamics of cylindrical domains. A detailed discussion is given of the laws of motion of cylindrical magnetic domains under the influence of inhomogeneities of magnetic field, temperature, and plate thickness. Phase transitions in a lattice of domains are considered, and the singularities of the magnetization and magnetic susceptibility in such phase transitions are determined. A theory is given for waves propagated in a lattice of domains. Detailed consideration is given to the effect of external factors and of the parameters of the magnetic material on the dynamical properties of a lattice of domains.

Fundamental questions of the theory of gravitational waves are considered, and the properties of these waves are compared with those of electromagnetic waves. The efficiency of possible sources of gravitational radiation, both astronomical and in the laboratory, is analyzed. The principles on which detecting devices work are explained and their sensitivities are estimated. Particular attention is devoted to a new direction—the emission and detection of gravitational waves by means of electromagnetic systems. One of the variants of a laboratory experiment including a source and detector of electromagnetic type is described. The mechanism by which an isotropic blackbody background radiation of gravitons could have been formed is discussed, together with possibilities for detecting it.

Estimates for the scale, geometry and strength of the magnetic field in the galactic system can be derived from observations of polarization properties of radio emission from the Galaxy, extragalactic radio sources and pulsars, and polarization of starlight. Within distances of about 500 parsecs (1 parsec = 3.26 lightyears) from the solar system the magnetic field is directed towards galactic longitude l≈45°, while at distances extending over a few kiloparsec its average direction is towards l≈90°. Seen on a large scale the magnetic field in the Galaxy may be directed parallel to the galactic plane and along the spiral arms. The field may consist of a regular component and a random component with small scale variations of about 50 parsec in size. The strength of both components is of the same order of magnitude, about 2×10^–6 Gauss (this is about 6×10^–6 times the magnetic field strength of the earth).