Experimental results on the determination of the color temperature in shock waves produced with lasers are presented. The method is based on imaging the target rear side in two different spectral windows and on using phased zone plates to produce high-quality shocks. The shock velocity is also measured, allowing, with the use of the equation of state, the real shock temperature to be deduced and compared with the measured color temperature.

The problem of hydrodynamic stability is important for inertial confinement fusion (ICF) systems based upon high compression of fuel before its ignition. This problem for the case of complicated multilayer foils has been studied here by a new approach describing the development of Rayleigh-Taylor or interchange instability in compressible media with inhomogeneous distribution of “entropy”s = ρ/ρk, ∂ where K = (∂ In ρ/∂ In ρ)s is an adiabatic derivative taken in the local hydrostatic values of ρ and ρ. Inhomogeneous distribution of s simulates the dynamics of development of perturbations of multilayer flyer foils and shells. Besides instability, the same approach has been used for analysis of ID pulsations of a levitated foil. The problem of pulsations is real in the case of foils. Indeed, (1) an ablative acceleration is equivalent to an effective gravity field, which causes the appearance of an atmospheric-type distribution of thermodynamic functions, (2) the duration of ablative flight of foil is at least several times larger than the time that is necessary for an acoustic wave to travel from one side of the foil to another side, and (3) there is a strong initial impulse that initiates the motion of foil. This impulse together with (1, 2) is a reason for the powerful pulsations of foils. The period of pulsations is defined by the velocity of sound in the foil material, which is dependent on the derivatives of an equation of state (EOS). The check of the derivatives gives us finer information concerning the current state of matter and the EOS than the usual measurements of material velocity and pressure that are rougher measures. Therefore, an analysis of pulsations seems to be a promising tool for tracking the dynamics of flyer foil and for the definition of thermodynamic properties of matter.

The stopping power of dense nonideal plasmas is calculated in different approximations. The T-matrix approximation for binary collisions is compared with the random phase approximation (RPA) approximation for dielectric fluctuations. Within a microscopic model, the dynamical evolution of the velocity of the projectile is calculated. It reproduces well experimental values for the stopping of fast heavy ions. Further improvements due to correlations are discussed. Both concepts, cluster decomposition and memory, are compared and it is found that they lead to the same quantum virial corrections of the Beth-Uhlenbeck type in equilibrium. However, memory in the kinetic equation causes an additional renormalization of the effective energy transfer in nonequilibrium.

An expression for the stopping power is derived in the quantum T-matrix approximation. The transport cross sections needed for a numerical evaluation are calculated using a scattering phase-shift analysis. Numerical results are given for the stopping power of an electron beam running into an electron gas. The temperature and density dependencies of the stopping power are discussed. Finally, dynamical screening is included in the weak coupling limit according to a kinetic equation proposed by H.A. Gould and H.E. DeWitt.

Within the grand canonical ensemble, we use a general quantum statistical formula and the thermodynamic Green's functions to derive a perturbation expansion for the pressure of a multicomponent plasma. Different contributions to the equation of state (EOS) are given analytically and by numerical calculations. Exact results for the EOS are presented in the shape of a low-density expansion up to the order (ne2)5/2, including ladder-type contributions and “beyond Montroll–Ward” terms.

The concept of fast ignitor is intimately connected with the fundamental phenomenon of ultra-intense light beam propagation through dense matter in which kinetic effects combine with radiation pressure dominated hydrodynamics to form a complex scenario of extremely non-linear physics. In this paper, the fluid dynamic aspect of channel formation in a highly over-dense plasma is studied and possible attenuation mechanisms of the propagating pulse are evaluated in one dimension. Under the assumption that mass ablation reaches a quasistationary state, the radiation-assisted ablation pressure, the speed of the bow shock, and the density steepening around the critical point are determined self-consistently from the ID fluid conservation relations and the electromagnetic wave equation. Due to ponderomotive profile steepening, the ablation pressure is reduced by 40% in the subsonic region and is dominated by the radiation pressure in the supersonic domain. Channel lengths are calculated for various intensities and pellet compression ratios. Likewise, the nonlinear propagation of a superintense electromagnetic wave in an underdense plasma channel is investigated for the ID case with the help of a relativistic fluid model.

The interaction of relativistic electrons produced by ultrafast lasers and focussing them on strongly precompressed thermonuclear fuel is analytically modelled. Energy loss to target electrons is treated through binary collisions and Langmuir wave excitation. The overall penetration depth is determined by quasielastic and multiple scattering on target ions. Thus, it appears possible to ignite efficient hot spots in a target with density larger than 300 g/cc.

The very clean nuclear fusion reaction of hydrogen and boron-11 by inertial confinement arrives at conditions for power stations by volume ignition only at compressions to 100,000 times the solid state. The earlier (numerically) observed anomaly of decreasing gain at increasing density (retrograde behavior) is analyzed and the reason clarified: the strong stopping power mechanism, based on Gabor's collective model, is reaching its limit of too small Debye lengths at the extremely high densities because of the optimum temperature in the range of 30 keV due to the reabsorption of the bremsstrahlung. The relativistic correction of the bremsstrahlung for the always much higher temperatures after volume ignition is included from Maxon's model.

This paper discusses the implications of using different fuels, including pure deuterium, deuterium–tritium, deuterium–helium3, and proton–boron11, on safety and environmental compatibility of the fusion reactor, as well as on the driver requirements. Due to present-day technology limitations, it seems likely that the first generation of the fusion reactors will be based on a deuterium–tritium cycle. Such a scheme, however, would pose serious problems, including neutron activation and tritium handling. We show that by developing low-level tritium inertial fusion targets, one may substantially reduce the daily use of tritium in the reactor that may ultimately lead to a reduction in the overall tritium inventory in the power plant. Such reduced tritium targets will still generate sufficient energy to run the power plant economically.

This paper is reviewing the amplification of XUV radiation at 519.7 and 498.5 Å with a gain-length product of 2.5 and 2.2 for the 4f-3d and 4d-3p transition in an oxygen Z-pinch plasma. Time resolved measurements of the O VI (519.7 Å) transition were performed and the dependence of the line intensity on the discharge current and initial gas pressure is reported.

The equation of state and other thermodynamic functions of solids consisting of many electron atoms in strong magnetic fields arising in some laser experiments and astrophysical objects are calculated within the Kadomtzev's approach up to the high-pressure range. All static thermo-dynamic functions under consideration are obtained from the two-parametric scaling relations on the atomic number and magnetic field from the universal functions of the specific volume. At this high-pressure region, lattice dynamics of monoatomic solids in strong magnetic fields are considered. Vibrational spectra of face-centered cubic lattice of neon are obtained, which do not satisfy any scaling law and differ from that one in the absence of the magnetic field, especially in the long wave region.

We describe the role for the next-generation “superlasers” in the study of matter under extremely high-energy-density conditions in comparison with previous uses of nuclear explosives for this purpose. As examples, we focus on three important areas of physics that have unresolved issues that must be addressed by experiment: equations of state, hydrodynamic instabilities, and the transport of radiation. We describe some of the advantages the large lasers will have in a comprehensive, laboratory-based experimental program.

Results are presented for a theoretical model, known as the ion model (IM), recently elaborated to calculate the radiative opacity of a hot dense plasma. The model is based on the self-consistent field method for subsystems obeying Gibbs statistics. The results are compared with calculations that use the Hartree-Fock-Slater model and with experimental data. A theory is proposed to explain the extraordinary spectral line-shift phenomenon associated with such plasmas.