[en] The invention is concerned with enhancing the accuracy of determining the direction and energy of relativistic particles with reference to the Cherenkov radiation. With a view to increase the accuracy of measuring the slope of the particles path relative to the radiator normal, in case when their energy is determined at the same time, a measurement is made of the average angles of emission in mutually opposite directions from the beam, and the measurement results give the ground to estimate the parameters determined. The accuracy of determining the particle path slope in this manner is defined by the error of measuring half the difference between the angles, and, at an error of 1sup('), the average particle path angle is measured with an accuracy of 9sup('')

[en] Two possible methods for measuring the average energy of relativistic particles in collimated beams are described. The first method is, in fact, a simple conventional method (or the double reflection method) when a trigonal prism-radiator is added to a plane-parallel radiator. As a result, two cones of Vavilov-Cherenkov radiation are emitted from the faces of the prism-radiator. This makes it possible to make a four-fold measurement of the average particle energy and achieve twice as high the accuracy of the simple method during a single exposure. The second method is a combined one. It is, in fact, the so-called simple method (or too the double reflection method) added by an achromatic prism. This makes it possible to decrease considerably the required flux of particles and automatize the process of measuring the energy. The formulas and examples of calculations are given

[en] The difference method of measuring the average energy of relativistic collimated particles by means of Vavilov-Cherenkov radiation arising when particles pass through two plane-parallel radiators being in the optical contact is described. The calculation formulas for determining the average particle energy and the measurement errors are given. An example of calculating the dependence of the errors of particle velocity upon the measurement errors of the angle difference is presented. The attainable accuracy of the method, e.g., for protons with β=0.875 can be about 1.2 meV

[en] The paper proposes the simplest method for a practically complete elimination of the effect produced by Vavilov-Cherenkov radiation cone smearing due to dispersion on the resolution of Cherenkov counters operating under conditions close to the angle of total internal reflection (TIR). This is achieved by tilting the counter radiator output side (parallel to the particle velocity vector) by a small angle a. A formula for calculation of a and conditions for its applications are given. It is pointed out that the main difficulty in making use of the advantages of the obtained achromatization method is VChR diffraction. In view of its high sensitivity to the angular divergence of particles to be detected, this TIR counter is proposed to be used in experiments on particle scattering in the TeV energy region. 9 refs.; 3 figs.; 1 tab

[en] On the basis of the Vavilov-Cherenkov effect the anomaly in the transition radiation (TR) spectrum is explained which has been first observed by Boersch for grazing particle incidence on the silver surface. The contribution of the Vavilov-Cherenkov radiation to the angle distribution of photons of the TR is estimated. Special attention is drawn to a possibility of the nonthreshold character of Vavilov-Cherenkov radiation in such a medium as silver, and to a necessity of creating a complete theory of Vavilov-Cherenkov radiation for absorbing media

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[en] A possibility is considered for thermonuclear ionition in the (d, t) mixture by the Vavilov-Cherenkov radiation from the beam of relativistic nuclei with a high atomic number. It is shown that if lead nuclei with the intensity approximately 10¹³ are accelerated to the energy 5.7 GeV/nucl. exceeding the Vavilov-Cherenkov radiation thresiold in the radiator from sodium fluoride (NaF) 5 cm thick in the wave length range from 2000 A to 7000 A, the light energy of approximately 155 J is emitted. The proposed optical system allows one to produce two colliding synchronous beams of radiation and squeeze them from two sides to concentrate them on a special target, area approximately 1 mm², which allows a light flux of approximately 1.55x10¹³ W/cm², duration of the bunch accelerated nuclei being 1 ns. This is enough to produce a demonstrative thermonuclear ''microexplosion'' in the mode of ablation compression of the target. Requirements to the parameters of the relativistic nuclear beam and the opticai device are given

[en] The angular distributions of transition radiation (TR) arising on the vacuum-metal boundary and directed towards metal have been calculated on the basis of TR general equations. Such properties of Vavilov-Cherenkov radiation in the absorbing medium as its directional property, polarization and radiation energy are considered in detail. Special attention is drawn to the considerable contribution of VaVilov-Cherenkov radiation to the intensity of the radiation, observed in experiments on optical TR. In particular, the coincidence of theoretical and experimental curves in the case of the systematic anticoincidence of TR levels is explained. A new explanation is given to the appearance of the perpendicular component. Different ''forward'' and ''backward'' background levels are explained

[en] A short history survey of magnetic charge investigations based on the complete bihliograpo covering t perid of 1892-1980 is presented. A classification of all experimental searches for the Dirac monopole carried out during this period is given. Numerous theoretical approaches and increased interest in the problem are noted

[en] The properties of transition radiation (TR) originating on charged particle crossing the vacuum-transparent dielectric boundary has been analyzed in detail. This made it possible to observe the interference effect between the transition and Cherenkov radiations in a pure form. An unusual kind of the quantum angular distribution of TR (a distribution with a minimum) arising near the threshold of Vavilov-Cherenkov radiation and directed to a transparent medium has been observed. The shape of the total TR intensity due to the presence of minima in the angular distributions of TR has also a peculiarity in the prethreshold region (the total intensity is decreased with increasing γ). It is shown that this effect can be explained only on studying the radiation from the charge-image. The summed TR emitted in a medium by a particle with β>n^-1 is a result of the interference of three radiations: TR from a particle, HR from a particle and TR (hybrid) from a particle-image