The National Ignition Facility Project

The mission of the National Ignition Facility is to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project

Small Inertial Fusion Energy (IFE) demonstration reactors

ICF target design studies done for the Nova Upgrade have identified conditions under which the target ignition ``cliff`` is shifted to much lower drive energy albeit with the penalty that the gain achieved at a given energy is also smaller. These targets would repeatedly produce the output and spectra of a higher gain targets at low yield. They should, thus, allow building much smaller R&D reactors with full thermonuclear effects. Demonstration reactor at the 1 to 100 MW{sub e} level appear to be feasible with driver energies of 0.5 to 2.0 MJ per pulse. These smaller, less expensive test and demonstration facilities should result in lower IFE development cost. If the U.S. government builds a driver and target factory, it is also conceivable that commercial organizations could build their own scaled concepts of IFE reactors using the beams and targets supplied by the government`s facilities

Progress in the ICF Program at the Lawrence Livermore National Laboratory

Experiments using the harmonically converted Nd:glass lasers at the Lawrence Livermore National Laboratory (Novette with 2 to 10 kJ at 0.26 and 0.53 micron and Nova with 30 to 80 kJ at 0.35 and 0.53 micron) have demonstrated favorable coupling of laser light to fusion targets. The coupling of short-wavelength laser light to these plasmas is now well understood and is primarily collisional in nature, in contrast to previous experiments at 1.06 microns and 10 microns, where the coupling was collective. Increased absorption and conversion to x-rays and decreased production of suprathermal electrons was measured with decreasing wavelength. Stimulated Raman scattering was identified as the primary source of the suprathermal electrons. The collisionality of the laser target coupling can be controlled by the proper selection of laser wavelength and target material. The coupling improvements led directly to the demonstration of higher-density ablative implosions of DT fusion fuel. Experiments on Novette demonstrated a better than 100-fold compression of the DT fuel with two-sided illumination. The Nova laser is extending laser-plasma studies to plasmas several times larger than those used on Novette. Recent experiments have produced a yield of over 10/sup 13/ neutrons. Temporally shaped pulses on Nova will be used to compress DT fuel close to the 200 g/cm/sup 3/ densities ultimately required for high-gain target performance

Directions of ICF research in the United States

Inertial Confinement Fusion (ICF) research in the United States is in a dramatic upswing. Technical progress continues at a rapid pace and with the start of construction of the National Ignition Facility (NIF) this year the total U.S. budget for ICF for fiscal year 1997 stands at $380 million. The NIF is being built as an essential component of the U.S. Stockpile Stewardship and Management Program, which has been formulated to assure the continued safety, reliability and performance of the downsized nuclear weapons stockpile in the absence of nuclear tests. Thus the increase in funding originates in the Congressional armed services committees and is managed by Defense Programs of the Department of Energy. The NIF, however, is a fundamental research tool that will be of great benefit beyond its mission within the nuclear weapons program. Its experiments will promote fusion energy development and will open new areas of basic scientific research. This paper will discuss some of the directions that ICF research is now taking, the progress on the NIF Project, and the potential impact that these developments are likely to have on fusion energy development and on certain areas of the basic sciences

Transport of Nordic Seas Overflow Water Into and Within the Irminger Sea: An Eddy-Resolving Simulation and Observations

Results from a climatologically forced, eddy-resolving (1/12 degrees) Atlantic simulation using the Hybrid Coordinate Ocean Model help clarify some presently unresolved connections between volume transports of Nordic Seas overflow water at key locations in the northernmost North Atlantic Ocean. The model results demonstrate that, in addition to the known westward flow through the Charlie Gibbs Fracture Zone (CGFZ), some Iceland Scotland overflow water (ISOW) flows westward through gaps in the Reykjanes Ridge north of the CGFZ into the Irminger Sea, and some flows southward along the eastern flank of the Mid-Atlantic Ridge into the West European Basin. These results provide insights into the well-known inconsistency between observed westward transport of ISOW through the CGFZ (2.4 Sv) and the transports upstream at Southeast of Iceland section (3.2 Sv) and downstream in the western Irminger Sea (4.5 Sv). Although the portion of the simulated ISOW that flows through CGFZ is about 500 m deeper than observed, the model results also show two ISOW pathways of this flow into the Irminger Sea, one northward along the western flank of the Reykjanes Ridge and the other westward before turning north-eastward on the western side of the Irminger Basin. Comparisons with the long-term moored instrument database in the Irminger Sea show that the model-based mean circulation is in reasonable agreement with observed volume transports of overflow water and that it gives approximately correct temperature and salinity characteristics

Early Results of a Phase II Study Adding Peri-Transplant Rituximab to Nonmyeloablative Conditioning and Allogeneic Hematopoietic Cell Transplantation (HCT) for Patients (PTS) with High-Risk Fludarabine-Refractory Chronic Lymphocytic Leukemia (Cll)

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Scaffolding School Pupils’ Scientific Argumentation with Evidence-Based Dialogue Maps

This chapter reports pilot work investigating the potential of Evidence-based Dialogue Mapping to scaffold young teenagers’ scientific argumentation. Our research objective is to better understand pupils’ usage of dialogue maps created in Compendium to write scientific ex-planations. The participants were 20 pupils, 12-13 years old, in a summer science course for “gifted and talented” children in the UK. Through qualitative analysis of three case studies, we investigate the value of dialogue mapping as a mediating tool in the scientific reasoning process during a set of learning activities. These activities were published in an online learning envi-ronment to foster collaborative learning. Pupils mapped their discussions in pairs, shared maps via the online forum and in plenary discussions, and wrote essays based on their dialogue maps. This study draws on these multiple data sources: pupils’ maps in Compendium, writings in science and reflective comments about the uses of mapping for writing. Our analysis highlights the diversity of ways, both successful and unsuccessful, in which dialogue mapping was used by these young teenagers

Chemical derivation to enhance the chemical/oxidative stability of resorcinol-formaldehyde (R-F) resin

Tank wastes at Hanford and SRS contain highly alkaline supernate solutions of conc. Na, K nitrates with large amounts of {sup 137}Cs. It is desirable to remove and concentrate the highly radioactive fraction for vitrification. One candidate ion exchange material for removing the radiocesium is R-F resin. This report summarizes studies into synthesis and characterization of 4-derivatized R-F resins prepared in pursuit of more chemically/oxidatively robust resin. 85% 4-fluororesorcinol/15% phenol formaldehyde resin appears to have good stability in alkaline solution, although there may be some nucleophilic displacement reaction during synthesis; further studies are needed