Recently revised estimates of target gain have added additional optimistic inputs to the interface between targets, accelerators and fusion chamber beam transport. But it remains valid that neutralization of the beams in the fusion chamber is useful if ion charge state Z > 1 or if > 1 kA per beamlet is to be propagated. Some engineering and economic considerations favor higher currents.

The collimators at Sector 30 of the SLAC accelerator are designed to scrape off a significant fraction (e.g., {approximately}20%) of the SLC beam. The electromagnetic cascade shower that develops in the collimator, and in the scraper and waveguide downbeam, leads to very high radiation exposures of TV cameras (and other devices) located nearby. The collimator (point) source accounts for one-third of the dose and is best shielded by extending the radius of the copper scraper. Radiation from the waveguide accounts for the remaining two-thirds of the dose, and is difficult to shield since it is a line source. However, the spectrum from the waveguide is expected to be softer than that from the collimator. This paper discusses shielding of these sources.

A Tektronix-31 (Tektronix Inc. Beaverton, Oregon) desk top calculator program, which is used as a backup to the PDP-8/I computer program, is described. The program yields interplanar (d) spacings and (2theta) angle values from measurements made on an x-ray diffraction film of a powdered sample of a crystalline material. Use of the calculator provides accurate computations in a relatively rapid time interval when the PDP-8/I is not functioning because of downtime for repairs, maintenance, etc.

Concepts of the range of investigation of a borehole gravimeter are reviewed. It is shown that the maximum sensitivity to a mass point at a horizontal distance R from a borehole occurs at a vertical distance Z = R/..sqrt..2. Thus, the angle of maximum sensitivity is about 55/sup 0/ from the vertical. It is also shown that the absolute value of the gravitational effect decreases with increasing R. There are two maxima of the vertical gradient of gravity (at Z = 0 and at Z = ..sqrt../sup 3///sub 2/ R). The minimum distance required between gravimeter stations to obtain a usable measurement can be determined. The slab radius R for which the gravitational effect of a horizontal slab is equal to 45%, 90%, etc., of that of an infinite horizontal slab is a function of the measurement spacing. The closer the measurement spacing, the more information obtained.

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X-ray lasers have been extensively studied around the world since the first laboratory demonstration on the Novette laser at LLNL in 1984. The characteristic properties of short wavelength, high monochromaticity, collimation and coherence make x-ray lasers useful for various applications. These include demonstrations of biological imaging within the water window, interferometry of laser plasmas and radiography of laser-heated surfaces. One of the critical issues has been the high power pump required to produce the inversion. The power scaling as a function of x-ray laser wavelength follows a {approx} {lambda}{sup -4} to {approx} {lambda}{sup -6} law. The shortest x-ray laser wavelength of {approx}35 {angstrom} demonstrated for Ni-like Au was at the limit of Nova laser capabilities. By requiring large, high power lasers such as Nova, the shot rate and total number of shots available have limited the rapid development of x-ray lasers and applications. In fact over the last fifteen years the main thrust has been to develop more efficient, higher repetition rate x-ray lasers that can be readily scaled to shorter wavelengths. The recent state of progress in the field can be found in references. The objective of the project was to develop a soft x-ray laser (XRL) pumped by …

For heavy-ion fusion energy applications, Mark and Yu have derived hydrodynamic models for numerical simulation of energetic pinched-beams including self-pinches and external-current pinches. These pinched-beams are applicable to beam propagation in fusion chambers and to the US High Temperature Experiment. The closure of the Mark-Yu model is obtained with adiabatic assumptions mathematically analogous to those of Chew, Goldberger, and Low for MHD. Features of this hydrodynamic beam model are compared with a kinetic treatment.

The principal aim of the National Waste Terminal Storage (NWTS) program is to develop repositories in several different rock formations in various parts of the country. Rocks such as salt, shale, limestone, and granite may qualify as host media for the disposition of radioactive wastes in the proper environments. In general, the only requirement for any rock formation or storage area is that it be able to contain any emplaced wastes for so long as it takes for the radioactive materials to decay to innocuous levels. This requirement, though, is a formidable one because some of the wastes will remain active for periods of hundreds of thousands of years and because the physical and chemical properties of rocks that govern circulating ground water and, hence, the containment may be difficult to determine and define. Rock salt has long been regarded as the most favored geologic medium for the containment of radioactive wastes in the United States. This stems largely from the plastic behavior of salt, which promotes self-healing and otherwise makes it impermeable to circulating ground water. Other important advantages of salt include its wide distribution, ease of mining, and favorable heat dissipation characteristics. In addition to the salt domes …

Algebraic multigrid (AMG) is an attractive choice for solving large linear systems {Lambda}x = b on unstructured grids. While AMG is applicable as a solver for a variety of problems, its robustness may be enhanced by using it as a preconditioner for Krylov solvers, such as GMRES. The sheer size of modern problems, hundreds of millions or billions of unknowns, dictates the use of massively parallel computers. AMG consists of two phases: the setup phase, in which smaller and smaller linear systems are generated by means of linear transfer operators (interpolation and restriction); and the solve phase, which employs a smoothing operator, such as Gauss-Seidel or Jacobi relaxation. Most of these components can be parallelized in a straightforward fashion; however, the coarse-grid selection, in which the grid for a smaller linear system is created on which the error can be approximated, is highly sequential. It is important to develop parallel coarsening techniques. They briefly present here the coarsening algorithms used in the parallel AMG code ''Boomer AMG'' and summarize some performance results for those algorithms. A detailed discussion of the algorithms and numerical results will be found.

The design of high power UV laser systems is limited to a large extent by the laser-initiated damage performance of transmissive fused silica optical components. The 3{omega} (i.e., the third harmonic of the primary laser frequency) damage growth mitigation LDRD effort focused on understanding and reducing the rapid growth of laser-initiated surface damage on fused silica optics. Laser-initiated damage can be discussed in terms of two key issues: damage initiated at some type of precursor and rapid damage growth of the damage due to subsequent laser pulses. The objective of the LDRD effort has been the elucidation of laser-induced damage processes in order to quantify and potentially reduce the risk of damage to fused silica surfaces. The emphasis of the first two years of this effort was the characterization and reduction of damage initiation. In spite of significant reductions in the density of damage sites on polished surfaces, statistically some amount of damage initiation should always be expected. The early effort therefore emphasized the development of testing techniques that quantified the statistical nature of damage initiation on optical surfaces. This work led to the development of an optics lifetime modeling strategy that has been adopted by the NIF project to …

Dimensional changes in PBX materials resulting from temperature change are of interest to engineers, designers and modelers. In this paper we present data from recent measurements made on LX17-1, as well as on the material's binder and its energetic constituent. LX17-1 is made from 7.5% KEL-F 800 binder combined with 92.5% wet aminated TATB energetic crystals. Due apparently to the anisotropic expansionary behavior of the TATB, the material exhibits irreversible growth, in addition to the usual reversible expansions and contractions associated with temperature change. In an effort understand reversible and irreversible growth behavior and to verify consistency between our measurements and those made historically, measurements were performed on billet pressed LX17-1, on die pressed TATB, and on KEL-F alone. It is important to realize that, for materials involving TATB, expansionary behavior results from the combined effects of reversible and irreversible (ratchet growth) phenomena.

Ultrasonic (UT) and computed tomography (CT) evaluation of a P/M ring gear was performed at LLNL to characterize the gear and to determine the relative sensitivity of the two techniques to defects of interest. The features of concern lie at the root of the teeth and in layers along the sides of the teeth. These layers can be detected using metalography but success depends on chance and the number of sections polished. Much of the current focus is on improving the sensitivity of the CT scan and on better ways to evaluate the large data sets obtained. The initial data obtained showed anomalies close to the gear teeth as expected. Later data showed anomalies at other locations and in other orientations. Figure 3 shows a radiograph with vertical and horizontal CT slices through regions with anomalies.

We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an active negative feedback bias. We demonstrated the effects of active bias such as additional pulse shortening, reduction of TES change in temperature during a pulse, and linearization of energy response at low energy. Linearization at higher energy is possible with optimized heat capacities and thermal conductivities of the microcalorimeter. However, the current fabrication process has low control and repeatability over the thermal properties. Thus, optimization of the detector performance is difficult until the fabrication process is improved. Currently, several efforts are underway to better control the fabrication of our gamma-ray spectrometers. We are developing a full-wafer process to produce TES films. We are investigating the thermal conductivity and surface roughness of thicker SiN membranes. We are exploring alternative …

With the advent of fast computer systems, Scientists are now able to generate terabytes of simulation data. Unfortunately, the shear size of these data sets has made efficient exploration of them impossible. To aid scientists in gathering knowledge from their simulation data, we have developed an ad-hoc query infrastructure. Our system, called AQSim (short for Ad-hoc Queries for Simulation) reduces the data storage requirements and access times in two stages. First, it creates and stores mathematical and statistical models of the data. Second, it evaluates queries on the models of the data instead of on the entire data set. In this paper, we present two simple but highly effective statistical modeling techniques for simulation data. Our first modeling technique computes the true mean of systematic partitions of the data. It makes no assumptions about the distribution of the data and uses a variant of the root mean square error to evaluate a model. In our second statistical modeling technique, we use the Andersen-Darling goodness-of-fit method on systematic partitions of the data. This second method evaluates a model by how well it passes the normality test on the data. Both of our statistical models summarize the data so as to answer …

A national security need as well as environmental monitoring need exists for networks of sensors. The advantages of a network of sensors over a single sensor are improved range, sensitivity, directionality, and data readability. Depending upon the particular application, sensors can be acoustic, chemical, biological, thermal or inertial. A major desire in these sensor networks is to have the individual sensor and associated electronics small and low enough in power that the battery can also be small and of long life. Smaller, low power sensor nodes can allow more nodes per network. A typical network for security applications is depicted in Figure 1. Here a number of sensor nodes are deployed around a central hub node in a star configuration. In this scenario the hubs communicate with each other and ultimately relay information to a satellite. Future networks might follow this scenario or some other network architecture such as a hopping network where individual nodes communicate directly with each other. The focus of our research has been on development of the small low power nodes and less on the overall network topology. However, some consideration of the network must be given when designing the nodes and some consideration of the …

Uncertainties in climate observations are revealed when alternate observationally based data sets are compared. General circulation model-based ''reanalyses'' of meteorological observations will yield different results from different models, even if identical sets of raw unanalyzed data form their starting points. We have examined 25 longitude-latitude fields (including selected levels for three-dimensional quantities) encompassing atmospheric climate variables for which the PCMDI observational data base contains two or more high-quality sources. For the most part we compare ECMWF with NCEP reanalysis. In some cases, we compare in situ and/or satellite-derived data with reanalysis. To obtain an overview of the differences for all 25 fields, we use a graphical technique developed for climate model diagnosis: a ''portrait diagram'' displaying root-mean-square differences between the alternate data sources. With a few exceptions (arising from the requirement that RMS differences be normalized to accommodate different units of variables) the portrait diagrams indicate areas of agreement and disagreement that can be confirmed by examining traditional graphics such as zonal mean plots. In accord with conventional wisdom, the greatest agreement between alternate data sets--hence the smallest implied observational uncertainty--occurs for upper tropospheric zonal wind. We also find fairly good agreement between reanalysis and more direct measures of precipitation, …

Production of Pu nitrate, UO{sub 3}, and unfabricated Pu metal met schedules. Decontamination performance of Purex process continued below standard. The cerium-144 cask is being redesigned. A ``powered ferret``, for driving a scintillation counter through a conduit to monitor ground activity beneath waste storage tanks, is being designed.

This document discusses increases in water pressure from the 190 Building process pumps which has been contemplated for a range of pressures up to 550 PSIG. The existing process pumps are dual units, consisting of a steam turbine driven primary pump operated: in series with an electric driven secondary pump. The secondary pumps installed in 100-B, D, F, and H Areas were designed for 400 PSIG working pressure, and were given factory hydrostatic tests of 600 PSIG. The 100-DR pumps were given factory hydrostatic tests of 650 PSIG. The Ingersoll-Rand Company advises that a working pressure of 425 PSIG is as high as they would-recommend for pump casing pressure on the secondary pumps. In consideration of problems incident to increased operating pressures, the immediate limiting factor is the total head pressure permissible on secondary pump casings. Other limiting factors are filter plant capacities, and 183 process water capacities.

Characteristics of the heavy water moderated and cooled reactor when fueled with natural uranium were compared with those of Hanford. The following topics were covered: (1) fundamental safety of the Savannah River Plant reactor and its fundamental efficiency as neutron collector; (2) many critical volumes result in a complex control system and high sensitivity of flux pattern to rod position changes; (3) due to lack of time had to sue slugs initially; (4) had to use D{sub 2}O sparingly; (5) effects of circulating cooling system; and (6) heat transfer considerations. Topics also discussed were Savannah River reactor with enriched loadings and irradiation of thorium in lieu of lithium alloy.

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WARPrz is a 2.5 dimensional, cylindrically symmetric, electrostatic, particle-in-cell code. It is part of the WARP family of codes which has been developed to study heavy ion fusion driver issues. WARPrz is being used to study the longitudinal dynamics of heavy ion beams including a longitudinal instability that is driven by the impedance of the LINAC accelerating modules. This instability is of concern because it can enhance longitudinal momentum spread; chromatic abhoration in the lens system restricts the amount of momentum spread allowed in the beam in the final focusing system. The impedance of the modules is modeled by a continuum of resistors and capacitors in parallel in WARPrz. We discuss simulations of this instability including the effect of finite temperature and reflection of perturbations off the beam ends. We also discuss intermittency of axial confining fields (``ears`` fields) as a seed for this instability.

Deep Space Program Science Experiment (DSPSE), also known as Clementine, is a collection of science experiments conducted in near-earth with the goal of demonstrating Strategic Defense Initiative Office (SDIO) developed technologies. The 785 lb (fully fueled) spacecraft will be launched into low Earth orbit in February 1994 together with a Star 37 solid kick motor and interstage. After orbit circulation using Clementine`s 110 lb Delta-V thruster, the Star 37 will execute a trans-lunar injection burn that will send the spacecraft toward lunar obit. The 110-lb will then be used in a sequence of burns to insert Clementine into a trimmed, polar orbit around the moon. After a two month moon mapping mission, Clementine will execute burns to leave lunar orbit, sling-shot around Earth, and flyby the moon on a 9.4 million km journey toward the asteroid Geographos. After about three months in transit, Clementine will attempt a flyby with a closest point of approach of 100 km from the asteroid on August 31, 1994. During its approach to Geographos, Clementine will be tracked by the Deep Space Network (DSN) and receive guidance updates. The last update and correction burn will occur about one day out of the flyby. Multiple experiments …

The Multifunction Storage Unit, Type I is a storage device capable of storing geometrical information in visual display form. The storage is accomplished by means of an electrostatic storage cathode ray tube. The Storage Unit consists of this storage tube and its associated circuitry. Associated circuitry is considered to be all circuitry required by the storage tube itself which is necessary to make the unit a self-contained storage unit. The following six external signals are all that is required in order to write, store and erase in the unit: vertical deflection signal, horizontal deflection signal, gate signal, z axis signal, erase signal (local or remote) and AC power. The erase signal causes the entire screen to be erased and primed for writing.

The beams in a Heavy Ion beam driven inertial Fusion (HIF) accelerator must be focused onto small spots at the fusion target, and so preservation of beam quality is crucial. The nonlinear self-fields of these space-charge-dominated beams can lead to emittance growth; thus a self-consistent field description is necessary. We have developed a multi-dimensional discrete-particle simulation code, WARP, and are using it to study the behavior of HIF beams. The code`s 3d package combines features of an accelerator code and a particle-in-cell plasma simulation, and can efficiently track beams through many lattice elements and around bends. We have used the code to understand the physics of aggressive drift-compression in the MBE-4 experiment at Lawrence Berkeley Laboratory (LBL). We have applied it to LBL`s planned ILSE experiments, to various ``recirculator`` configurations, and to the study of equilibria and equilibration processes. Applications of the 3d package to ESQ injectors, and of the r, z package to longitudinal stability in driver beams, are discussed in related papers.