The target chamber of an inertial confinement fusion (ICF) power plant or high-yield test facility must be designed to absorb the target produced Xrays and ions and survive the resulting effects. The target chamber conditions must be restored in fractions of a second for high repetition rate power applications. Computer modeling of these phenomena is essential because equivalent conditions cannot be produced in laboratory experiments prior to the first ignition of high-yield ICF targets. Choices of models are dictated by specific reactor design strategies. The two major strategies, gas protection and sacrificial first surfaces, are used as a guide to our discussion. Physical models for ion, electron, and X-ray deposition are discussed, along with physical and numerical modeling of the resulting phase changes intarget chamber structures. The hydrodynamics and radiative transfer in the target chamber vapors and plasmas are central topics.

The growth of the Rayleigh-Taylor instability in three dimensions is ex amined during the deceleration phase of an inertial confinement fusion implosion. A detailed discussion of the three-dimensional hydrocode, PLATO, is presented. A review of previous calculations is given, concentrating on theshape of the R-T instability in three dimensions. Results of the growth rate during the linear phase, the saturation amplitude, and the nonlinear evolution are presented.

The different physical models, computational methods, and results describing the properties of a plasma produced by an ultrashort laser pulse interacting with a solid target at different laser intensities are presented. The basic issues affecting the laser-plasma interaction are considered, including: the different absorption mechanisms; the formation of a transient, nonequilibrium, asymmetric electron distribution function; the energy losses; the role of instabilities and the ponderomotive force; ion expansion and acceleration; and surface wave propagation along the boundary of the plasma. The article concludes with a discussion of the range of applicability of the different approximations and future perspectives for the field.

Various problems involved in the simulation of current X-ray laser experiments are discussed. The methods are based on laser-plasma simulation techniques with simultaneous calculation of the ionization dynamics, and are particularly appropriate for collisional and recombination pumped systems.

The radiation hydrodynamics in laser-produced high-energy-density plasmas has been successfully simulated by means of the MULTI hydrocode. It is used in combination with the SNOP atomic physics code, which uses a steady-state screened hydrogenic explicit ion model and which generates non-LTE opacity tables for MULTI. After a brief general review of the modeling of the radiation hydrodynamics in laser-produced plasmas, the underlying physical models of MULTI and SNOP are described in detail, with particular emphasis on atomic physics. Examples of simulations of the radiation transport in laser plasmas are presented. They include a laser-irradiated gold foil and a radiatively heated carbon foil.

Modern numerical simulations of hot dense plasma require atomic data including equations of state, opacities, and coupling coefficients for energy exchange between photons, electrons, and fast and thermal ions. While these coefficients may be calculated by complicated quantum-statistical theories, in many cases the simpler semi-classical theory gives a reasonably accurate first approximation.

Fokker-Planck (FP) codes have become useful tools for modeling nonlocal heat-transport phenomena in laser-produced plasmas. Several possible simplifications to the FP equation as well as different numerical techniques available for its solution are investigated. The most robust and efficient approach is found to involve the diffusive approximation of the FP equation and the alternating-direction-implicit method of solution. The SPARK FP code, which has been developed along these principles, is described in detail. It incorporates fluid ions and solves for transport on either a two-dimensional Eulerian grid or a one-dimensional Lagrangian grid. Sample simulation results are presented, together with a discussion of possible improvements to the code.

ELBA is a three-dimensional, particle-in-cell, simulation code that has been developed to study the propagation and transport of relativistic charged particle beams. The code is particularly suited to the simulation of relativistic electron beams propagating through collisionless or slightly collisional plasmas or through external electric or magnetic fields. Particle motion is followed via a coordinate “window” in the laboratory frame that moves at the speed of light. This scheme allows us to model only the immediate vicinity of the beam. Because no information can move in the forward direction in these coordinates, particle and field data can be handled in a simple way that allows for very large scale simulations. A mapping scheme has been implemented that, with corrections to Maxwell's equations, allows the inclusion of bends in the simulation system.

The computational tools used in the investigation of light-ion diode physics at Sandia National Laboratories are described. Applied-B ion diodes are used to generate intense beams of ions and focus these beams onto targets as part of Sandia's inertial confinement fusion program. Computer codes are used to simulate the energy storage and pulse forming sections of the accelerator and the power flow and coupling into the diode where the ion beam is generated. Other codes are used to calculate the applied magnetic field diffusion in the diode region, the electromagnetic fluctuations in the anode-cathode gap, the subsequent beam divergence, the beam propagation, and response of various beam diagnostics. These codes are described and some typical results are shown.