ALBERT

Notes: The enhanced plasma stopping of energetic (MeV/amu) multicharged ions is experimentally confirmed by inserting a fully ionized hydrogen column on a tandem accelerator ion beam line. Relevance to heavy ion driven inertial compression is emphasized. Measured energy losses are quantitatively matched by a theoretical extension of the cold matter stopping formula (Bethe).

Notes: The electromagnetic stopping of intense and relativistic electron beams (REB) arising from femtosecond lasers interacting with a precompressed deuterium+tritium (DT) fuel is investigated within the Bohr–Fermi formalism with a large impact parameter. Dynamical intrabeam correlations through long-range collision with target electrons are shown to be quantitatively significant for various arrangements of projectile electrons and the overall REB penetration in the DT fuel. One thus expects much shorter stopping ranges yielding an easier access to fuel ignition through hot spots production. © 1999 American Institute of Physics.

Notes: A fully electromagnetic particle in cell-Monte Carlo (PIC-MCC) code is considered for the ballistic transport of intense ion beams in a reaction chamber field with Flibe gas surrounding a pellet with a thermonuclear fuel in it. A specific emphasis is given to a self-consistent treatment of beam boundary conditions. Spurious electromagnetic waves are evacuated out of the grid, and a modified Maxwell system corrects for Gauss theorem error. A dynamical grid with self-adaptating field follows beam convergence. Final ion propagation in the Hylife II [R. Moir, Fusion Technol. 29, 306 (1991)] scheme and also in the space charge compensated one is investigated at length. For the first, a partial beam neutralization is identified only through electron background. The second displays an acceptable focalization at pellet, the background electron temperature has a significant influence on beam minimum radius. Transverse emittance is given specific attention.© 1998 American Institute of Physics.

Notes: All the Thomas–Fermi approaches to the thermodynamics and atomic physics properties of dense and ionized matter consisting of a single element are systematically derived and compared within a density-functional theoretical framework. The corresponding results are contrasted to those of the average atom model by using similar approximations for exchange, correlation, and gradient corrections. Emphasis is led on equations of state, ionization, level shifts, and radial moments. The same numerical algorithms are used to unravel similar trends or identify specific ones, in terms of density and temperature variations. The most sophisticated Thomas–Fermi–Dirac–Weizäcker method yields the closest results to the hybrid average atom model using quantized bound states. Parameters ranges of potential interest for inertially confined thermonuclear fusion stress out density in the 0.1–10 times the solid, and temperature up to 10 keV. © 1996 American Institute of Physics.

Notes: Heavy-ion clusters are considered for driving directly a pellet for inertial confinement fusion. They are shown to be effective at much lower energy than requested for heavy atomic ions. Multifragmentation, arising from a Coulomb explosion, in the target, is discussed with a maximum entropy hypothesis. Direct driving pressure imparted to a deuterium–tritium (DT) pellet is estimated through the ion debris range in the target. The correlated stopping of N ions flowing close to the initial projectile trajectory is seen to be much larger than the uncorrelated one. Specific attention is paid to a few regular geometrics of cluster ion debris stopped in a lithium pusher. The calculations elaborate on the very high driving pressure obtained, for the case of a solid-state density of cluster ion projectiles around the pellet (moving tamper). A target containing 4 mg of deuterium and tritium fuel is demonstrated to be thus imploded in 5 nsec. A driving pressure of 500 Mbars yields an energy output of 630 MJ. This result can be obtained with an initial cluster kinetic energy smaller than 20 keV/amu.

Notes: This paper is devoted to a systematic investigation of linear transport properties in strongly coupled binary ionic mixtures of pointlike ions interacting solely through Coulomb interactions. The basic formalism rests upon suitable extensions of the Boltzmann–Ziman equation. Validity conditions for the Lorentzian approximation are thoroughly discussed. High temperature and inelastic contributions to electron transport are emphasized. The formalism is, hereafter, specialized to a thorough investigation of electric, thermal, and mechanical transport coefficients. Basic transport quantities are expressed under a reduced form that allows an easy analytical treatment of temperature and inelastic corrections, parametrized with α=T/TF and (large-closed-square)=β(h-dash-bar)ω, respectively. The former are derived from exact solutions of transport equation through various jellium dielectric functions. Calculation of inelastic contributions is performed through the variational method. Electron transport at T=0 is then thoroughly investigated, including electric and thermal conductivities as well as thermopower and shear viscosity. These results are furthermore extended to an exact calculation of the electric conductivity up to order α2 including properly inelastic contributions, derived in terms of successive moments of the ion–ion structure factors.Results are presented under an analytic and compact form, convenient for a numerical implementation to strongly coupled H+–He2+ mixtures of astrophysical interest. Calculations are performed within binary ionic mixture (BIM) and polarized BIM (PBIM) frameworks, respectively. Ion–ion structure factors are computed through the hypernetted-chain (HNC) scheme, by neglecting bridge diagrams. Most of these results pertain to homogeneous phases. First, the focus is on BIM and a systematic investigation of the Γ-rs and c2 dependence of the transport quantities is performed. Also, attention is paid to the influence of the jellium dielectric function. The T=0 elastic limit is considered first. Next, inelastic and finite temperature corrections are addressed, and BIM to PBIM results are compared. Finally, the electric resistivity behavior is investigated in the vicinity of critical demixing. Discrepancy between BIM and PBIM are thus stressed.