Waste management has reached paramount importance in recent years. The successful management of radioactive waste is a key ingredient in the successful operation of any nuclear facility. This paper discusses the options available for on-site storage of low-level radioactive waste and those options that have been selected by the Department of Energy facilities operated by Martin Marietta Energy Systems, Inc. in Oak Ridge, Tennessee. The focus of the paper is on quality assurance (QA) features of waste management activities such as accountability and retrievability of waste materials and waste packages, retrievability of data, waste containment, safety and environmental monitoring. Technical performance and careful documentation of that performance are goals which can be achieved only through the cooperation of numerous individuals from waste generating and waste managing organizations, engineering, QA, and environmental management.

Plasma generated in low-density vapor by a negative ion beam has been studied experimentally and computationally. We show that space charge neutralization of the beam occurs at very low vapor density, and that correspondingly the electron density may be much less than the beam and plasma ion densities. When there is a large local gas density, as in a charge changing cell, the resulting high electron density is also localized to the same region. Therefore, very few electrons will reach a negative ion accelerator even if it is placed one or two beam diameters from such a cell.

Regional-scale climate change and associated societal impacts result from large-scale (e.g. well-mixed greenhouse gases) and more local (e.g. land-use change) 'forcing' (perturbing) agents. It is essential to understand these forcings and climate responses to them, in order to predict future climate and societal impacts. California is a fine example of the complex effects of multiple climate forcings. The State's natural climate is diverse, highly variable, and strongly influenced by ENSO. Humans are perturbing this complex system through urbanization, irrigation, and emission of multiple types of aerosols and greenhouse gases. Despite better-than-average observational coverage, we are only beginning to understand the manifestations of these forcings in California's temperature record.

The configuration interaction (CI) approach to solving the nuclear many-body problem, also known as the interacting shell model, has proven to be powerful tool in understanding the structure of nuclei. The principal criticism of past applications of the shell model is the reliance on empirical tuning to interaction matrix elements. If an accurate description of nuclei far from the valley of stability, where little or no data is available, a more fundamental approach is needed. This starts with recent ab initio approaches with effective interactions in the no-core shell model (NCSM). Using effective-field theory for guidance, fully ab initio descriptions of nuclei up to {sup 16}O with QCD based NN, NNN, and NNNN interactions will be possible within the next five years. An important task is then to determine how to use these NCSM results to develop effective interactions to describe heavier nuclei without the need to resort to an empirical retuning with every model space. Thus, it is likely that more traditional CI applications utilizing direct diagonalization and more fundamental interactions will be applicable to nuclei with perhaps up to one hundred constituents. But, these direct diagonalization CI applications will always be computationally limited due to the rapid increase …

Passing an electron beam through an aperture can serve to reduce the beam current or change the transverse beam profile. For a sufficiently intense beam, space charge will drive a radial expansion of the beam, which may cause the current passing through the aperture to increase even though the current arriving at the aperture is decreasing. When a gridded electron gun is used, this may be expressed by stating that the transconductance of the apertured gun is negative. Here we explain this effect, and explore some of the key factors governing when it can occur and influencing its strength.

The self-assembly of tetradecylamine (C14) and of mixtures of tetradecyl and octadecylamine (C18) molecules from chloroform solutions on mica has been studied using atomic force microscopy(AFM). For pure components self-assembly proceeds more slowly for C14 than for C18. In both cases after equilibrium is reached islands of tilted molecules cover a similar fraction of the surface. Images of films formed by mixtures of molecules acquired before equilibrium is reached (short ripening time at room temperature) show only islands with the height corresponding to C18 with many pores. After a long ripening time, when equilibrium is reached, islands of segregated pure components are formed.

The combination of lithography and self-assembly provides apowerful means of organizing solution-synthesized nanostructures for awide variety of applications. We have developed a fluidic assembly methodthat relies on the local pinning of a moving liquid contact line bylithographically produced topographic features to concentratenanoparticles at those features. The final stages of the assembly processare controlled first by long-range immersion capillary forces and then bythe short-range electrostatic and Van der Waal's interactions. We havesuccessfully assembled nanoparticles from 50 nm to 2 nm in size usingthis technique and have also demonstrated the controlled positioning ofmore complex nanotetrapod structures. We have used this process toassemble Au nanoparticles into pre-patterned electrode structures andhave performed preliminary electrical characterization of the devices soformed. The fluidic assembly method is capable of very high yield, interms of positioning nanostructures at each lithographically-definedlocation, and of excellent specificity, with essentially no particledeposition between features.

In the proposed E-166 experiment at SLAC, 50 GeV electrons pass through a helical undulator, and produce circularly polarized photons, which interact with a tungsten target and generate longitudinally polarized positrons. The background is an important issue for an experiment under consideration. To address this issue, simulations were performed with the code GEANT3 to model the production of secondary particles from high-energy electrons hitting an undulator. The energy density of photons generated at the target has been analyzed. Results of the simulations are presented and discussed.

To study microwave instability the tracking code is developed. For bench marking, results are compared with Oide-Yokoya results [1] for broad-band Q = 1 impedance. Results hint to two possible mechanisms determining the threshold of instability.

We show that the solid lower bound of about 10{sup -44} cm{sup 2} is obtained for the cross section between the supersymmetric dark matter and nucleon in a theory in which the supersymmetric fine-tuning problem is solved without extending the Higgs sector at the weak scale. This bound arises because of relatively small superparticle masses and a fortunate correlation that the two dominant diagrams for the dark matter detection always interfere constructively if the constraint from the b {yields} s{gamma} measurements is obeyed. It is, therefore, quite promising in the present scenario that the supersymmetric dark matter is discovered before the LHC, assuming that the dark matter is the lightest supersymmetric particle.

We present a scheme to solve the nonlinear multigroup radiation diffusion (MGD) equations. The method is incorporated into a massively parallel, multidimensional, Eulerian radiation-hydrodynamic code with adaptive mesh refinement (AMR). The patch-based AMR algorithm refines in both space and time creating a hierarchy of levels, coarsest to finest. The physics modules are time-advanced using operator splitting. On each level, separate 'level-solve' packages advance the modules. Our multigroup level-solve adapts an implicit procedure which leads to a two-step iterative scheme that alternates between elliptic solves for each group with intra-cell group coupling. For robustness, we introduce pseudo transient continuation ({Psi}tc). We analyze the magnitude of the {Psi}tc parameter to ensure positivity of the resulting linear system, diagonal dominance and convergence of the two-step scheme. For AMR, a level defines a subdomain for refinement. For diffusive processes such as MGD, the refined level uses Dirichet boundary data at the coarse-fine interface and the data is derived from the coarse level solution. After advancing on the fine level, an additional procedure, the sync-solve (SS), is required in order to enforce conservation. The MGD SS reduces to an elliptic solve on a combined grid for a system of G equations, where G is the …

A shot automation framework has been developed and deployed during the past year to automate shots performed on the National Ignition Facility (NIF) using the Integrated Computer Control System This framework automates a 4-8 hour shot sequence, that includes inputting shot goals from a physics model, set up of the laser and diagnostics, automatic alignment of laser beams and verification of status. This sequence consists of set of preparatory verification shots, leading to amplified system shots using a 4-minute countdown, triggering during the last 2 seconds using a high-precision timing system, followed by post-shot analysis and archiving. The framework provides for a flexible, model-based execution driven of scriptable automation called macro steps. The framework is driven by high-level shot director software that provides a restricted set of shot life cycle state transitions to 25 collaboration supervisors that automate 8-laser beams (bundles) and a common set of shared resources. Each collaboration supervisor commands approximately 10 subsystem shot supervisors that perform automated control and status verification. Collaboration supervisors translate shot life cycle state commands from the shot director into sequences of ''macro steps'' to be distributed to each of its shot supervisors. Each Shot supervisor maintains order of macro steps for each …

A velocimetry experiment has been designed to measure shock properties for small cylindrical metal targets (8-mm-diameter by 2-mm thick). A target is accelerated by high explosives, caught, and retrieved for later inspection. The target is expected to move at a velocity of 0.1 to 3 km/sec. The complete experiment canister is approximately 105 mm in diameter and 380 mm long. Optical velocimetry diagnostics include the Velocity Interferometer System for Any Reflector (VISAR) and Photon Doppler Velocimetry (PDV). The packaging of the velocity diagnostics is not allowed to interfere with the catchment or an X-ray imaging diagnostic. A single optical relay, using commercial lenses, collects Doppler-shifted light for both VISAR and PDV. The use of fiber optics allows measurement of point velocities on the target surface during accelerations occurring over 15 mm of travel. The VISAR operates at 532 nm and has separate illumination fibers requiring alignment. The PDV diagnostic operates at 1550 nm, but is aligned and focused at 670 nm. The VISAR and PDV diagnostics are complementary measurements and they image spots in close proximity on the target surface. Because the optical relay uses commercial glass, the axial positions of the optical fibers for PDV and VISAR are offset …

In this experiential paper we report on lessons learned during the development ofthe data acquisition software for the IceCube project - specifically, how to effectively address the unique challenges presented by a distributed, collaborative, multi-institutional, multi-disciplined project such as this. While development progress in software projects is often described solely in terms of technical issues, our experience indicates that non- and quasi-technical interactions play a substantial role in the effectiveness of large software development efforts. These include: selection and management of multiple software development methodologies, the effective useof various collaborative communication tools, project management structure and roles, and the impact and apparent importance of these elements when viewed through the differing perspectives of hardware, software, scientific and project office roles. Even in areas clearly technical in nature, success is still influenced by non-technical issues that can escape close attention. In particular we describe our experiences on software requirements specification, development methodologies and communication tools. We make observations on what tools and techniques have and have not been effective in this geographically disperse (including the South Pole) collaboration and offer suggestions on how similarly structured future projects may build upon our experiences.

This paper contains viewgraph material assessing the density limits and fueling limits of different thermonuclear devices. Various density limits are considered with emphasis on the Murakami limit and the Hugill limit. (GSP)

Results are presented from tests of the third full scale development dipole magnet for the Superconducting Super Collider and from a retest of a 4.5 m model magnet of the same design mounted in an SSC cryostat. The 4.5 m magnet shows consistent quench performance between its original tests in boiling liquid helium in a vertical dewar and the current tests in forced flow helium in a horizontal cryostat. Little or no retraining is observed over several thermal cycles. The full length magnet requires 12 quenches to train to its short sample limit of 6800 A and displays a reasonably stable quench plateau following training. This represents a great improvement over the performance of the first two full length magnets. Data are presented on quench behavior as a function of current and temperature and on azimuthal and longitudinal loading of the coil by the support structure. 14 refs., 7 figs.

The results of recent numerical simulations of supernova explosions are presented and a variety of topics discussed. Particular emphasis is given to (i) the nucleosynthesis expected from intermediate mass (10sub solar less than or equal to M less than or equal to 100 Msub solar) Type II supernovae and detonating white dwarf models for Type I supernovae, (ii) a realistic estimate of the ..gamma..-line fluxes expected from this nucleosynthesis, (iii) the continued evolution, in one and two dimensions, of intermediate mass stars wherein iron core collapse does not lead to a strong, mass-ejecting shock wave, and (iv) the evolution and explosion of vary massive stars (M greater than or equal to 100 Msub solar of both Population I and III. In one dimension, nuclear burning following a failed core bounce does not appear likely to lead to a supernova explosion although, in two dimensions, a combination of rotation and nuclear burning may do so. Near solar proportions of elements from neon to calcium and very brilliant optical displays may be created by hypernovae, the explosions of stars in the mass range 100 M/sub solar/ to 300 M/sub solar/. Above approx. 300 M/sub solar/ a black hole is created by stellar …

A Mach-Zehnder interference microscope was automated which quickly characterizes and sorts transparent microspheres. It takes only 12 seconds to measure a 3 micron thick glass microsphere.

We have developed processes for mass producing the quality glass microspheres required for current laser fusion experiments. We describe the advances in the methods and materials used in our liquid droplet and dried gel systems.

The quenching and stability behavior of forced-flow helium-cooled, cable-in-conduit conductors (CICC) has been analyzed using a new computer program. This computer analysis code was developed for performing general, transient, thermal analyses on CICCs. The program includes the necessary details for the physical properties of all the constituent materials of such conductors, and accurately models the thermo- and fluid-dynamic behavior of the helium coolant starting from a wide range of initial conditions. It has been applied to a study of the stability and quench behavior of several large-scale conductor options being considered for use in the magnet systems of the International Thermonuclear Experimental Reactor (ITER), and the results will be reported here. 3 refs., 14 figs.

In August 1987, a routine Ames test on soot from the Lawrence Livermore National Laboratory (LLNL) 4-in. gun showed that the soot was mutagenic to Salmonella bacteria. Subsequent liquid chromatography on the soot showed that, out of hundreds of ultravoilet-absorbing compounds found in the residue, only three or four were mutagenic. When a sample large enough to weigh was collected, it was found that No environmentally identified complex mixture has ever been reported with as much Ames/Salmonella activity per gram as the gun residues.'' Since then, Ames tests of hundreds of samples have verified that the residues from our gun tanks may be hazardous to health. The actual degree of the hazard and the identity of the offending chemicals are still unknown. 2 refs.

The Fusion ENgineering International eXperimental (FENIX) Test Facility which is nearing completion at Lawrence Livermore National Laboratory, is a 76-t set of superconducting magnets housed in a 4-m-diameter cryostat. It represents a significant step toward meeting the testing needs for the development of superconductors appropriate for large-scale magnet applications such as the International Thermonuclear Experimental Reactor (ITER). The magnet set is configured to allow radial access to the 0.4-m-diameter high-field region where maximum fields up to 14 T will be provided. The facility is fitted with a thermally isolated test well with a port to the high-field region that allows insertion and removal of test conductors without disturbing the cryogenic environment of the magnets. It is expected that the facility will be made available to magnet developers internationally, and this paper discusses its general design features, its construction, and its capabilities.

As indicated by tests on several cameras, the dynamic range of the Lawrence Livermore Laboratory streak-camera system appears to be about two orders of magnitude greater than those reported for other systems for 10- to 200-ps pulses. The lack of a fine mesh grid in the RCA streak tube used in these cameras probably contributes to a lower system dynamic noise and therefore raises the dynamic range. A developmental tube with a mesh grid was tested and supports this conjecture. Order-of-magnitude variations in input slit width do not affect the spot size on the phosphor or the dynamic range of the RCA tube.

We have developed a program called FUDGE that allows one to modify data from LLNL's nuclear database. After modifying data, FUDGE can then be instructed to process the data into the formats used by LLNL's deterministic (ndf) and the Monte Carlo (MCAPM) transport codes. This capability allows users to perform nuclear data sensitivity studies without modification of the transport modeling codes. FUDGE is designed to be user friendly (object-oriented) and fast (the modification and processing typically takes about a minute). It uses Python as a front-end, making it flexible and scriptable. Comparing, plotting and printing of the data are also supported. An overview of FUDGE will be presented as well as examples.