[en] A sequential model of multiple vacancy production according to which the vacancies are created in successive collisions of a fast ion with electrons belonging to a definite shell of an atom, with different single electron ionization probabilities, is discussed. A simple formula for the probability distribution of the multiple vacancy production is derived in the framework of this model which must be valid for sufficiently highly charged ions. Comparison of this formula with experiments shows that the sequential model allows discrepancies between the widely used binomial distribution and these experiments to be explained without invoking any fitted parameters. (Author)

[en] A general problem of interaction of intensive neutralized ion beams with isolated metal or dense plasma targets is investigated with the help of Boltzmann equation involving appropriate boundary conditions taking into account emission of secondary electrons provoked by these beams. It is shown in the framework of this kinetic theory that the emission of the secondary electrons and back - scattering of the electrons moving with the ion beams can lead to an appreciable loading of an isolated target. These loading effects can be particularly important for the case of an ICF pellet situated in a reaction chamber filled by a dense gas and irradiated by beams of light ions

[en] A general investigation of the electrical conductivity for radio-frequency (RF) fields in strongly magnetized plasmas with small-scale density fluctuations is performed within the cold plasma hydrodynamical approximation. It is shown that in such plasmas an RF phenomenon similar to the Bohm diffusion exists: the presence of stochastic RF electric field in a turbulent plasma can lead to a strong enhancement of the RF currents flowing in the direction of the applied electric field components transverse to the magnetic field. The appearance of these turbulent drift currents favours energy transfer from the RF fields to the plasma and thus leads to their stronger damping. This effect allows us to interpret quantitatively the enhanced damping of the magnetosonic waves observed in several experiments. The magnetized radially inhomogeneous cylindrical plasmas in these experiments are characterized by density fluctuations due to drift instabilities. The theory has also a number of other applications; an example is given of the whistlers damped by the ionospheric density fluctuations. (author)

[en] Anomalous attenuation of magnetosonic oscillations driven in an r.f.-plasma and its dependence on the observed low-frequency density fluctuations are investigated. The fluctuations are identified by digital spectral analysis technique as unstable collisional drift modes leading to drift wave turbulence. A dielectric tensor accounting for the anisotropic turbulence is given and the anomalous attenuation of the externally driven oscillations is explained by the drift wave turbulence. The experiments are performed in a linear device. Typical plasma parameters are: mean electron density n-barsub(e) = 1.5x10¹² cm^-3, electron temperature Tsub(e) = 2.5 eV, magnetic field B₀ = 2 kG, filling gas pressure p₀ = 3x10^-4 torr argon. (author)

[en] The electrical conductivity of an inhomogeneous magnetized turbulent plasma for weak electromagnetic fields has been studied theoretically and experimentally. The theory predicts a resistivity for radio frequency fields essentially controlled by the density fluctuations and the anisotropy of the turbulence. In order to determine these parameters the turbulent behaviour and driving mechanism have been examined. The theory is checked looking at the magnetoacoustic resonance behaviour which is very sensitive to the conductivity of the plasma. The plasma was produced by microwave discharges. The magnetoacoustic oscillations were excited using a long single turn coil as an antenna. The wave field profiles and the resonant amplification of the exciting magnetic field were measured. On the basis of the agreement between theory and experiments it is concluded that the anomalous damping of the magnetoacoustic oscillations can be explained mainly by the influence of drift-wave turbulence. (Auth.)

[en] It is shown that strong noncompensated positive charges can arise in the metal ablator-pusher shell of the ICF-pellet as a result of back-scattering of electrons co-moving with the beam ions. These charges provoke fields in the metal shell of the order of 1 MV/cm. The presence of these fields can lead to some pellet plasma instabilities (eg ion-acoustic instability) and, thus, may influence the energy deposition by the beam ions. (author)

[en] A workable form of the longitudinal dielectric functions for classical TCP consisting of electrons and ions having charge Z is found on the basis of BBGKY approach in the first approximation in plasma parameter g = 3/4 π r³sub(d)n, rsub(d) = (T/4 π n e²)sup(1/2, n, T being plasma electron density and temperature. Calculation of collective losses of ions in such plasmas performed with these dielectric functions show that the losses can be influenced essentially by the correlational effects. The correlational effects can influence essentially stopping power of nonideal ablator-pusher plasmas containing high-Z ions, especially at the preheat stage. The same is true for plasmas arising as result of metal foil irradiation by intensive ion beams. (author)

[en] Analytic and numerical solutions of the problem of the interaction of intense ion beams with matter in the form of plane targets are considered. The theory of the interaction of protons with matter at low energies is discussed and calculations are presented for the energy loss of protons in aluminium and gold. Zero and one dimensional models are developed and the results are compared to numerical simulations carried out with the one dimensional Lagrangian hydrodynamic code MEDUSA which has been extended to include the various physical effects needed to carry out realistic simulations of the interaction of ion beams with matter. The theory and simulation of the acceleration of foils by intense ion beams is also considered and representative results are given. The theoretical results are used to investigate the optimum conditions in which to carry out stopping power experiments for ions in hot dense plasmas. These results are needed in order to perform more realistic pellet calculations for inertial fusion. (author)