This paper shows work at Lawrence Livermore National Lab (LLNL) devoted to modeling the propagation of, and heating by, a relativistic electron beam in a idealized dense fuel assembly for fast ignition. The implicit particle-in-cell (PIC) code LSP is used. Experiments planned on the National Ignition Facility (NIF) in the next few years using the Advanced Radiography Capability (ARC) short-pulse laser motivate this work. We demonstrate significant improvement in the heating of dense fuel due to magnetic forces, increased beam collimation, and insertion of a finite-radius carbon region between the beam excitation and fuel regions.

We are designing a full hydro-scale cone-guided, indirect-drive FI coupling experiment, for NIF, with the ARC-FIDO short-pulse laser. Current rad-hydro designs with limited fuel jetting into cone tip are not yet adequate for ignition. Designs are improving. Electron beam transport simulations (implicit-PIC LSP) show: (1) Magnetic fields and smaller angular spreads increase coupling to ignition-relevant 'hot spot' (20 um radius); (2) Plastic CD (for a warm target) produces somewhat better coupling than pure D (cryogenic target) due to enhanced resistive B fields; and (3) The optimal T{sub hot} for this target is (almost equal to) 1 MeV; coupling falls by 3x as T{sub hot} rises to 4 MeV.

Thereexistawiderangeofapplicationswhereasigni?cantfractionofthe- mentum and energy present in a physical problem is carried by the transport of particles. Depending on the speci?capplication, the particles involved may be photons, neutrons, neutrinos, or charged particles. Regardless of which phenomena is being described, at the heart of each application is the fact that a Boltzmann like transport equation has to be solved. The complexity, and hence expense, involved in solving the transport problem can be understood by realizing that the general solution to the 3D Boltzmann transport equation is in fact really seven dimensional: 3 spatial coordinates, 2 angles, 1 time, and 1 for speed or energy. Low-order appro- mations to the transport equation are frequently used due in part to physical justi?cation but many in cases, simply because a solution to the full tra- port problem is too computationally expensive. An example is the di?usion equation, which e?ectively drops the two angles in phase space by assuming that a linear representation in angle is adequate. Another approximation is the grey approximation, which drops the energy variable by averaging over it. If the grey approximation is applied to the di?usion equation, the expense of solving what amounts to the simplest possible description of transport is roughly equal to the cost of implicit computational ?uid dynamics. It is clear therefore, that for those application areas needing some form of transport, fast, accurate and robust transport algorithms can lead to an increase in overall code performance and a decrease in time to solution.

In the fall of 2010, the Office of the U.S. Department of Energy's (DOE's) Secretary for Science asked for a National Research Council (NRC) committee to investigate the prospects for generating power using inertial confinement fusion (ICF) concepts, acknowledging that a key test of viability for this concept-ignition -could be demonstrated at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in the relatively near term. The committee was asked to provide an unclassified report. However, DOE indicated that to fully assess this topic, the committee's deliberations would have to be informed by the results of some classified experiments and information, particularly in the area of ICF targets and nonproliferation. Thus, the Panel on the Assessment of Inertial Confinement Fusion Targets ("the panel") was assembled, composed of experts able to access the needed information. The panel was charged with advising the Committee on the Prospects for Inertial Confinement Fusion Energy Systems on these issues, both by internal discussion and by this unclassified report. A Panel on Fusion Target Physics ("the panel") will serve as a technical resource to the Committee on Inertial Confinement Energy Systems ("the Committee") and will prepare a report that describes the R&D challenges to providing suitable targets, on the basis of parameters established and provided to the Panel by the Committee. The Panel on Fusion Target Physics will prepare a report that will assess the current performance of fusion targets associated with various ICF concepts in order to understand: 1. The spectrum output; 2. The illumination geometry; 3. The high-gain geometry; and 4. The robustness of the target design. The panel addressed the potential impacts of the use and development of current concepts for Inertial Fusion Energy on the proliferation of nuclear weapons information and technology, as appropriate. The Panel examined technology options, but does not provide recommendations specific to any currently operating or proposed ICF facility.

This book is on inertial confinement fusion, an alternative way to produce electrical power from hydrogen fuel by using powerful lasers or particle beams. It involves the compression of tiny amounts (micrograms) of fuel to thousand times solid density and pressures otherwise existing only in the centre of stars. Thanks to advances in laser technology, it is now possible to produce such extreme states of matter in the laboratory. Recent developments have boosted laser intensities again with new possibilities for laser particle accelerators, laser nuclear physics, and fast ignition of fusion targets. This is a reference book for those working on beam plasma physics, be it in the context of fundamental research or applications to fusion energy or novel ultra-bright laser sources. The book combines quite different areas of physics: beam target interaction, dense plasmas, hydrodynamic implosion and instabilities, radiative energy transfer as well as fusion reactions. Particular attention is given to simple and useful modelling, including dimensional analysis and similarity solutions. Both authors have worked in this field for more than 20 years. They want to address in particular those teaching this topic to students and all those interested in understanding the technical basis.