Hrachya B. Nersisyan

Dielectric response function and stopping power of dense magnetized plasma

Using a kinetic-theoretic approach to Fokker–Planck equilibrium of thermonuclear α particles in dense and magnetized plasmas, the corresponding longitudinal dielectric function is investigated at length. It is used to evaluate the energy loss of the αs′ through the excitation of collective plasma modes. Specific attention was paid to the case of extreme magnetization, as well as to the parallel stopping of α particles in dense and hot plasmas of magnetized target fusion (MTF) interest. Maximum stopping is shown to be strongly dependent on magnetic field intensity.

Microfield distributions in strongly coupled two-component plasmas

The electric microfield distribution at charged particles is studied for two-component electron-ion plasmas using molecular dynamics simulation and theoretical models. The particles are treated within classical statistical mechanics using an electron-ion Coulomb potential regularized at distances less than the de Broglie length to take into account the quantum-diffraction effects. The potential-of-mean-force (PMF) approximation is deduced from a canonical ensemble formulation. The resulting probability density of the electric microfield satisfies exactly the second-moment sum rule without the use of adjustable parameters. The correlation functions between the charged radiator and the plasma ions and electrons are calculated using molecular dynamics simulations and the hypernetted-chain approximation for a two-component plasma. It is shown that the agreement between the theoretical models for the microfield distributions and the simulations is quite good in general.

Stopping of ions in a plasma irradiated by an intense laser field

The inelastic interaction between heavy ions and an electron plasma in the presence of an intense radiation field (RF) is investigated. The stopping power of the test ion averaged with a period of the RF has been calculated assuming that

Dicluster stopping in a degenerate electron gas

\omega_{0} >\omega_{p}

Binary collisions of charged particles in a magnetic field

, where

Renormalized cluster expansion of the microfield distribution in strongly coupled two-component plasmas.

\omega_{0}

Number-conserving linear-response study of low-velocity ion stopping in a collisional magnetized classical plasma.

is the frequency of the RF and

Scattering and Transformation of Waves on Heavy Particles in Magnetized Plasma

\omega_{p}

An exact solution of the moving boundary problem for the expansion of a plasma cylinder in a magnetic field

is the plasma frequency. In order to highlight the effect of the radiation field we present a comparison of our analytical and numerical results obtained for nonzero RF with those for vanishing RF. It has been shown that the RF may strongly reduce the mean energy loss for slow ions while increasing it at high-velocities. Moreover, it has been shown, that acceleration of the projectile ion due to the RF is expected at high-velocities and in the high-intensity limit of the RF, when the quiver velocity of the plasma electrons exceeds the ion velocity.

Scattering of magnetized electrons by a moving heavy ion

In this paper we report on our theoretical studies of various aspects of the correlated stopping power of two pointlike ions (a dicluster) moving in close but variable vicinity of each other in some metallic target materials, the latter being modeled by a degenerate electron gas with appropriate densities. Within the linear-response theory we have made a comprehensive investigation of correlated stopping power, vicinage function and related quantities for a diproton cluster in two metallic targets, aluminum and copper, and present detailed and comparative results for three approximations to the electron gas dielectric function, namely, the plasmon-pole approximation without and with dispersion as well as with the random-phase approximation. The results are also compared, wherever applicable, with those for an individual projectile.