Instabilities for a relativistic electron beam interacting with a laser-irradiated plasma.

The effects of a radiation field (RF) on the unstable modes developed in a relativistic electron beam-plasma interaction are investigated assuming that ω(0) > ω(p), where ω(0) is the frequency of the RF and ω(p) is the plasma frequency. These unstable modes are parametrically coupled to each other due to the RF and are a mix between two-stream and parametric instabilities. The dispersion equations are derived by the linearization of the kinetic equations for a beam-plasma system as well as the Maxwell equations.

Energy loss of ions by electric-field fluctuations in a magnetized plasma.

The results of a theoretical investigation of the energy loss of charged particles in a magnetized classical plasma due to the electric-field fluctuations are reported. The energy loss for a test particle is calculated through the linear-response theory. At vanishing magnetic field, the electric-field fluctuations lead to an energy gain of the charged particle for all velocities.

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

The results of a theoretical investigation of the low-velocity stopping power of ions in a magnetized collisional and classical plasma are reported. The stopping power for an ion is calculated through the linear-response (LR) theory. The collisions, which lead to a damping of the excitations in the plasma, are taken into account through a number-conserving relaxation time approximation in the LR function.

Interaction of fast charged projectiles with two-dimensional electron gas: Interaction and collisional-damping effects.

The results of a theoretical investigation on the stopping power of ions moving in a two-dimensional degenerate electron gas are presented. The stopping power for an ion is calculated employing linear-response theory using the dielectric function approach. The collisions, which lead to a damping of plasmons and quasiparticles in the electron gas, is taken into account through a relaxation-time approximation in the linear-response function.

Energy loss of ions and ion clusters in a disordered electron gas.

The various aspects of the correlated stopping power of pointlike and extended ions moving in a disordered degenerate electron gas have been analytically and numerically studied. Within the linear response theory we have made a systematic and comprehensive investigation of correlated stopping power, vicinage function, and related quantities for protons and extended ions, as well as for their clusters. The disorder, which leads to a damping of plasmons and quasiparticles in the electron gas, is taken into account through a relaxation time approximation in the linear response function.

Interaction of ions and ion clusters with a disordered electron gas: collective and single-particle excitations.

In this paper, we report results on our theoretical studies of stopping power contributions from single-particle and plasmon excitations. We have introduced an equipartition ratio defined as the ratio of stopping contributions from plasmon and single-particle excitations, respectively. Within the linear response theory we have made a comprehensive investigation of this equipartition ratio for fast pointlike and extended projectile ions in a disordered electron gas; the latter is modeled by a degenerate electron gas of metallic densities and with disorder being incorporated within a relaxation-time approximation.