Heavy ion clusters are considered for driving an inertial confinement fusion (ICF) pellet. They are shown to be effective at much lower energy than required for atomic ions. Multifragmentation is discussed with a maximum entropy hypothesis. Direct pressure imparted to a DT pellet is estimated. The stopping of strongly correlated ion cluster debris flowing in a degenerate electron jellium target is calculated for polarized and unpolarized (with respect to velocity) projectiles. A reduced stopping occur for elongated configurations at low velocities (υ ⋍ 1 a.u.) and very dense targets. Transverse geometries experience a very large and enhanced stopping. Systematic trends are stressed out. Largest stopping is achieved when debris correlation lengths are smaller than the target jellium screening length.

Expressions for the stopping power are derived from the Lenard-Balescu and Boltzmann kinetic equations. Numerical evaluation is carried out for the stopping of light and heavy particles in a multicomponent plasma.

We present a diffusion approximation describing the flow of thermal radiation that preserves several important features of the underlying equation of radiative transfer. Specifically, this diffusion description: (1) is flux limited; (2) reduces to the correct transport weak gradient limit; (3) allows correct and simultaneous exponential growth and Decay for a certain class of problems; (4) gives correct transport results for certain contiguous half-space problems; and (5) allows the radiative flux and the gradient of the radiation energy density to point in independent directions. This treatment extends and generalizes earlier flux-limited diffusion approximations that are widely used in radiation–hydrodynamics calculations.

The plasma composition, equation of state, and phase diagram of dense helium plasma were calculated for temperatures of 104...105 K, total atom densities of 1015... 1025 cm−3, and pressures up to 102 TPa, including the region of partial ionization and strong Coulomb coupling. The basic thermodynamic potential was chosen to be the free energy density with contributions due to Coulomb interaction, hard-core repulsion, and van der Waals-like attraction for a mixture of differently charged atoms and free electrons. For the first time, we show the potential occurrence of a sequence of plasma phase transitions. In helium, they correspond to the ionization steps He0→He+ and He+→He++ respectively. The properties of the coexisting phases were determined by a Maxwell construction based on the combined chemical potential.

We develop a systematic comparison of thermodynamical and atomic properties computed within the three (TF, TFD, and TFDW) Thomas-Fermi modellings with results obtained from the average atom model. A special emphasis is placed on using the same analytic approximations for exchange, correlation, and gradient corrections. Analogies and discrepancies with respect to temperature behaviour are also stressed.

The knowledge of the properties of atoms in high-temperature/density plasmas is of deep interest in many fields of physics. Theoretical studies and interpretation of the inertial confinement fusion experiments is one of the examples. On the basis of the density functional formalism, a model of matter at extreme conditions is presented. Application of the model is illustrated by examples of average ionization state and equation of state calculations.

We propose a new formalism to electronic polarizability of dense, partially ionized plasmas. This formalism is based upon the density functional theory for the electronic equilibrium, the random phase approximation for the density response of electrons, and the cluster expansion in the averaging over ionic configurations. The first term in the final cluster expansion for the imaginary part of electron polarizability corresponds to the Lindhard dielectric function formula. The second term contains the electronic states of the average atom. The additional effects that result from this theory are: channel mixing (screening), “inverse Bremstrahlung” corrections, and free-bound electronic transitions. Our approach allows the plasma (collective) and atomic physics phenomena to be treated in the frame of one formalism. The theory can be applied for stopping power and opacity calculations.

The results of experimental studies of the interactions between high-intensity 25-ps pulses from a neodymium laser and tenuous plasmas are reviewed. Electrons expelled laterally from the laser focus regions were observed to have energies of up to 1.5 keV and both the maximum electron energy and the measured electron energy spectra were found to be characteristic of acceleration by ponderomotive forces, which usually are the main part of the general nonlinear forces. These results confirmed the naive force theory and emphasized the major importance of nonlinear effects at high laser intensities.

Non-local thermodynamic equilibrium radiative transfer calculations have been performed to predict emission spectra from plasma heated by intense proton beams. Multilevel, steady-state atomic rate equations were solved self-consistently with the radiation field to determine excitation and ionization populations. Ion beam effects were, included in the rate equations. Proton-impact ionization cross sections were calculated using a plane wave Born approximation model with Hartree-Fock wave functions for the electrons. We examined the dependence of emission spectra on the temperature and thickness of the plasma. In addition, Kα satellite line spectra were computed to assess its potential as a temperature diagnostic. Calculated Kα spectral results are compared with recent Particle Beam Fusion Accelerator II experimental data.

We study strongly correlated plasmas far from equilibrium with the ultimate aim of describing the cooling of heavy ion beams by electrons. With the help of molecular dynamics (MD) computer simulations, we conclude that the relaxation of a two-component plasma depends strongly upon the preparation of the initial configuration. If the initial data have no intercomponent correlations, such will build up during the evolution so that the intercomponent potential energy decreases while the kinetic energy increases. These effects become more pronounced for strongly coupled plasmas and limit the efficiency of electron cooling. We cannot confirm certain mean-field predictions on the influence of an external magnetic field on the cooling process. A study of the relaxation of anisotropic velocity distributions for a one-component plasma shows deviations from meanfield results for strongly coupled plasmas.

Simple circuit models for the terminal properties of a ferromagnetic closing switch are derived under the assumptions that the ferromagnetic material may be described by a hysteresis profile and that the driving H-field quickly becomes large. Comparison with results from a full transmission line model indicates that all but the simplest of these approximate models is extremely accurate for a realistic switch.

Dye lasers with bleaching wave (LBW) are the first condensed state lasers where the restriction on energy and duration of optical exciting pulses are practically removed. This gives an opportunity to create tunable lasers in the visible range with average powers significantly higher than that of any available laser of this type. Physical principles and current experimental results along with prospects of future LBW development are presented.