arXiv subjects

H. B. Nersisyan

Publications and source records attributed to H. B. Nersisyan.

23 records · Page 2Linked to original sources

arXiv1999

Excitation of Electromagnetic Wake Fields by one-dimensional Electron Bunch in Plasma in the Presence of Circularly Polarized Intense Electromagnetic Wave

The excitation of electromagnetic (EM) wake waves in electron plasma by an one-dimensional bunch of charged particles has been considered in the presence of intense monochromatic circularly polarized electromagnetic (CPEM) pump wave. In the zero state (in the absence of bunch) the interaction of the pump wave with plasma is described by means of Maxwell equations and relativistic nonlinear hydrodynamic equations of cold plasma. The excitation of linear waves by one-dimensional bunch is considered on this background. It is shown that there are three types of solutions of linear equations obtained for induced waves corresponding to three ranges of parameter values of the pump wave, bunch and plasma. In the first range of parameter values the amplitude of transverse components of induced waves is shown to grow as the bunch energy and after some value of the relativistic factor of the bunch to be almost independent of the energy and increase proportional to the intensity and frequency of the pump wave. The dependence of longitudinal component of induced waves on the relativistic factor of the bunch is weak. Its amplitude and wavelength grow as the intensity of pump wave. The second range of parameters is a resonance one. The amplitude of the wave excited by the bunch is a linear function of the distance to the bunch. In the third range of parameter values the longitudinal component of induced fields are localized near the bunch boundaries and are exponentially decreased with the increase in distance from these boundaries. The amplitudes of transverse components of induced waves reach a constant value with the distance from the bunch boundaries.

physics.plasm-ph↗

arXiv1998

Stopping of Charged Particles in a Magnetized Classical Plasma

The analytical and numerical investigations of the energy loss rate of the test particle in a magnetized electron plasma are developed on the basis of the Vlasov-Poisson equations, and the main results are presented. The Larmor rotation of a test particle in a magnetic field is taken into account. The analysis is based on the assumption that the energy variation of the test particle is much less than its kinetic energy. The obtained general expression for stopping power is analyzed for three cases: (i) the particle moves through a collisionless plasma in a strong homogeneous magnetic field; (ii) the fast particle moves through a magnetized collisionless plasma along the magnetic field; and (iii) the particle moves through a magnetized collisional plasma across a magnetic field. Calculations are carried out for the arbitrary test particle velocities in the first case, and for fast particles in the second and third cases. It is shown that the rate at which a fast test particle loses energy while moving across a magnetic field may be much higher than the loss in the case of motion through plasma without magnetic field.

physics.plasm-ph↗

arXiv1998

Stopping of Gyratory Fast Particle in Magnetized Cold Plasma

The energy loss by a test gyratory particle in a cold plasma in the presence of homogeneous magnetic field is considered. Analytical and numerical results for the rate of energy loss are presented. This is done for strong and weak fields (i. e., when the electron cyclotron frequency is either higher, or smaller than the plasma frequency), and in case, when the test particle velocity is greater than the electron thermal velocity. It is shown that the rate of energy loss may be much higher than in the case of motion through plasma in the absence of magnetic field.

physics.plasm-ph↗

arXiv1998

Correlated Fast Ion Stopping in Magnetized Classical Plasma

The results of a theoretical investigation on the stopping power of ion pair in a magnetized electron plasma are presented, with particular emphasis on the two-ion correlation effects. The analysis is based on the assumptions that the magnetic field is classically strong ($λ_B\ll a_c\ll λ_D$, where $λ_B$, $a_c$ and $λ_D$ are respectively the electron de Broglie wavelength, Larmor radius and Debye length) and that the velocity of the two ions is identical and fixed. The stopping power and % vicinage function in a plasma are computed by retaining two-ion correlation effects and is compared with the results of the individual-projectile approximation.

physics.plasm-ph↗

arXiv1998

The Dynamics of Charges Induced by a Charged Particle Traversing a Dielectric Slab

We studied the dynamics of surfacea and wake charges induced by a charged particle traversing a dielectric slab. It is shown that after the crossing of the slab first boundary, the induced on the slab surface charge (image charge) is transformed into the wake charge, which overflows to the second boundary when the particle crosses it. It is also shown, that the polarization of the slab is of an oscillatory nature, and the net induced charge in a slab remains zero at all stages of the motion.

physics.class-ph↗