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Gennady V. Kovalev

Publications and source records attributed to Gennady V. Kovalev.

15 recordsLinked to original sources
arXiv2014

Asymptotic Theory of Channeling in the Field of an Atomic Chain and an Atomic Plane

A rigorous theory of diffraction scattering from extended objects is proposed. The present theory is based on a multiple asymptotic expansion of an integral equation for the exact wave function in terms of the large parameters of the problem, which are the range of the potential and the momentum components of the incident particle. For small angles of incidence the density of positively charged particles on the axis of a chain is always lower than unit y and the density of negatively charged particles has a maximum for certain strength of the potential which can exceed considerably unity. The conditions of validity of the proposed approach are obtained.

cond-mat.other↗
arXiv2014

The Resonance Scattering Phenomenon of Fast Negatively Charged Particles in a Single Crystal

The energy spectrum of the extended attractive potential of a crystallographic row for negatively charged particles has quasi-bound states. It follows that a negatively charged particle with small transversal momentum component ($p_{\bot} R <<1$) may undergo resonance scattering. Thus the resonance scattering phenomenon can be observed in a single crystal, when fast electrons move with a small glancing angle ($θ_0 << 1/pR$) to a crystallographic axis. The calculated results for the electrons and angular widths of resonance peaks are consistent with experimental data.

cond-mat.mes-hall↗
arXiv2014

Gamma-ray Laser and Radiation from Collimated Particles

The motion of channeled particles is accompanied by the photon emission. This feature can be used for the stimulated generation of high energy photons, but the required density of channeled particles must be very high.

physics.optics↗
arXiv2014

Stimulated Emission of High-Frequency Phonons

The motion of channeled particles is accompanied by the phonon emission. This feature can be used for the stimulated generation of phonons with large wave vectors and frequencies.

cond-mat.other↗
arXiv2014

Resonance Scattering of Fast Electrons in a Single Crystal

It is shown that resonance scattering of fast ($pL > >pR > > 1$, $p$ is the particle momentum, $L$ is the longitudinal dimension of the potential, and $R$ is its transverse dimension) charged particles occurs in the extended potential. The data on small-angle scattering of fast electrons in the crystal are interpreted on the basis of the examined effect.

quant-ph↗
arXiv2014

Volume Reflection and Volume Refraction of Relativistic Particles in a Uniformly Bent Crystal

The scattering of fast charged particles in a bent crystal has been analyzed in the framework of relativistic classical mechanics. The expressions obtained for the deflection function are in satisfactory agreement with the experimental data for the volume reflection of relativistic protons obtained in [1,2,3]. The features of the scattering of the particles on ring potentials are considered in a wide range of impact parameters

math-ph↗
arXiv2014

On the Mechanism of the Volume Reflection of Relativistic Particles

The mechanisms of the volume reflection of positively and negatively charged relativistic particles in a bent crystal have been analyzed. It has been shown that the empty core effect is significant for the negatively charged particles. The average reflection angle of the negatively charged particles has been determined and the conditions for the observation of the reflection and refraction are discussed.

physics.plasm-ph↗
arXiv2014

Possibility of Observing Spiral Scattering of Relativistic Particles in a Bent Crystal

The peak position, impact-parameter range, and optimal conditions for observing spiral scattering of relativistic particles in a uniformly bent crystal are estimated. The existence of spiral scattering with a square-root singularity is pointed out. In this case, the secondary process of volume capture to the channeling mode is absent and the conditions for observing this effect are most favorable.

cond-mat.other↗
arXiv2013

Two-elliptic coordinates. Eigenfunctions and eigenvalues

The elliptic coordinates are used to build a new families of 2D coordinate systems which are orthogonal and admits the separation of variables. The charts of characteristic curves are constructed for these systems and compared with Mathieu's. The possible applications are in quantum mechanics, diffraction theory, vibrations and classical dynamics.

math-ph↗
arXiv2007

Volume Reflection and Refraction of Relativistic Particles in Bent Crystals

The quasi-channeling of positive and negative relativistic particles in a bent crystal is studied using the classical deflection function. It was shown that the potential scattering in a central field of bounded ring-like potentials may produce the ``reflected'' and ``refracted'' fractions of scattered particles. For particles with positive charge the ``reflected'' fraction is mainly presented; at the same time we predict that for particles with negative charge the ``refracted'' fraction should dominate. The effect of ``empty core'' for central scattering is also discussed. The average deflection angles for volume ``reflection'' and ``refraction'' are derived for accepted potential model of the crystal. The calculated average ``reflection'' angle is in satisfactory agreement with recent experimental data \cite{ivanov_2006}

physics.acc-ph↗
arXiv2007

The Volume Capture in Structures with Variable Curvature

The volume capture in classical relativistic mechanics is considered as a scattering process for the high energy charged particles in a field with no central or mirror symmetry. The parameters of volume capture for potentials with smooth variable curvature are received and analyzed.

physics.acc-ph↗
arXiv2007

A Possibility of Volume Refraction of Negative Relativistic Particles in Bent Crystals

The volume coherent deflection of high-energy positive and negative particles in uniformly bent crystals is studied. The general analysis of potential scattering shows that the standard screening potential for a large class of collisions can cause the volume refraction for negative particles (antiprotons, electrons) instead of the volume reflection for positive particles (proton, positrons).

physics.acc-ph↗
arXiv2004

Focusing limits of channeled high energy particles in bent crystals

The focusing of high energy charged particles by a bent crystal is considered. The limits and constraints of focusing imposed by dynamics of particles are pointed out. The crystalline geometry provided the maximum magnification and minimum focusing size is proposed. The focusing parameters are compared with current experimental results.

physics.acc-ph↗