Evidence from magnetospheric and solar flare research supports the belief that collisionless magnetic reconnection can proceed on the Alfven-wave crossing timescale. Reconnection behavior that occurs this rapidly in collisionless plasmas is not well understood because underlying mechanisms depend on the details of the ion and electron distributions in the vicinity of the emerging X-points. We use the direct implicit Particle-In-Cell (PIC) code AVANTI to study the details of these distributions as they evolve in the self-consistent E and B fields of magnetic reconnection. We first consider a simple neutral sheet model. We observe rapid movement of the current-carrying electrons away from the emerging X-point. Later in time an oscillation of the trapped magnetic flux is found, superimposed upon continued linear growth due to plasma inflow at the ion sound speed. The addition of a current-aligned and a normal B field widen the scope of our studies.

We examine magnetic field penetration in the Plasma Opening Switch, exploring, in particular, advective field penetration arising in conjunction with radial density gradients across the cathode anode gap. Our calculations have been completed with the implicit multi-fluid, ANTHEM code. We show favored penetration along a radial density jump, unstable plain wave penetration for a 1/(y {minus} y{sub {alpha}+{epsilon}}) density dependence (with y measured from cathode to anode at Y{sub {alpha}}) in planar switches, and the penetration of finger-like magnetic field perturbations, when the fill plasmas bears initial sinusoidal disturbances on its generator interface. 7 refs., 4 figs.

In 1987 the Department of Energy-Office of Special Applications (DOE-OSA) decided to transfer the iridium alloy Clad Vent Set (CVS) manufacturing for the General Purpose Heat Source (GPHS) program from EG G Mound Applied Technologies, Inc. (EG G-MAT) to the Oak Ridge Y-12 Plant operated by Martin Marietta Energy Systems, Inc. (Energy Systems). The reason for this transfer was to consolidate the GPHS program iridium hardware manufacturing. The CVS starting stock of iridium powder, foil, and blanks were already being manufactured at another Energy Systems facility - the Oak Ridge National Laboratory (ORNL). Since 1987 CVS manufacturing technology transfer efforts have taken place between EG G-MAT and Energy Systems. EG G-MAT retained all of their tooling, but they supplied all the necessary product drawings, specifications, and procedures, as well as their tooling drawings. Most of the tooling designs and processing steps were duplicated at the Y-12 Plant. Minor changes were required in both tooling design and processing steps, to accommodate particular health, safety, environmental, and manufacturing requirements at the Y-12 Plant. In order to evaluate the effects of the key Y-12 Plant processing modifications, four joint Y-12 Plant/EG G-MAT iridium CVS manufacturing qualification studies were organized. The successful completion of …

A computational model has been developed that calculates the thermal degradation of the reactor core of the production reactors at the Savannah River Site (SRS) under postulated severe accident conditions. This model addresses heatup and degradation of the U-Al fuel and Li-Al or U-metal target assemblies and neighboring structures. Models included are those for assembly heatup due to decay heat generation, material melting and relocation, volume expansion of fuel due to foaming and melt/debris accumulation in assembly bottom end-fittings. Sample results are presented that illustrate the effect of alternative assumptions regarding the temperature at which U-Al alloy melts and relocates and the extent to which fuel foaming thermally couples adjacent fuel and target tubes. 5 refs., 6 figs., 1 tab.

Charged particle multiplicity distributions from e{sup +}e{sup {minus}} annihilations at 29 GeV have been analyzed in selected rapidity and azimuthal angle intervals. The data were taken with the High Resolution Spectrometer at PEP. The factorial moments of the multiplicity distributions increase as the rapidity interval is decreased, the so-called intermittency phenomenon. These direct measurements of the moments agree with values derived from negative binomial fits to our multiplicity distributions in various central rapidity windows. The factorial moments are also given for the distribution in azimuthal angle around the beam direction and for the two-dimensional distribution in rapidity and azimuthal angle around the jet directions.

This report presents a method for calculating containment test leakage rates of radionuclides from an example spent fuel cask. Three releasable radioactive sources are considered: residual contamination in the cask cavity, crud on the fuel elements, and the radionuclides within the fuel rods. The ANSI N14.5 standard is used to calculate the test leakage rates from the maximum permissible releases determined from 10 CFR 71 containment requirements. 6 refs., 2 tabs.

We present experimental results and a model of Nd:glass disk amplifiers which are used in inertial confinement fusion research. We first review our previous measurements on pulsed xenon flashlamps. We then discuss out measurements on the enhancement of the Nd fluorescence decay rate in laser disks by amplified spontaneous emission. Using these data, we have constructed a model of flashlamp pumping which treats the transfer efficiency of pump light from the flashlamps to the disks as an empirical function. We have found a simple description of this cavity transfer function which provides an excellent fit to the amplifier results for various pump pulselengths. We discuss the concept of the pump area ratio for describing the flashlamp packing density and show that amplifier performance is optimized for values of this parameter near unity. We finally present results for both a single-segment and a multisegment disk amplifier. We have used these devices to investigate new amplifier designs for a large scale fusion driver. 11 refs., 13 figs.

We describe WARP, a new particle-in-cell code being developed and optimized for ion beam studies in true geometry. We seek to model transport around bends, axial compression with strong focusing, multiple beamlet interaction, and other inherently 3d processes that affect emittance growth. Constraints imposed by memory and running time are severe. Thus, we employ only two 3d field arrays ({rho} and {phi}), and difference {phi} directly on each particle to get E, rather than interpolating E from three meshes; use of a single 3d array is feasible. A new method for PIC simulation of bent beams follows the beam particles in a family of rotated laboratory frames, thus straightening'' the bends. We are also incorporating an envelope calculation, an (r, z) model, and 1d (axial) model within WARP. The BASIS development and run-time system is used, providing a powerful interactive environment in which the user has access to all variables in the code database. 10 refs., 3 figs.

Radioactive wastes are generated at many DOE laboratories, military facilities, fuel fabrication and enrichment plants, reactors, hospitals, and university research facilities. At all of these sites, wastes must be separated, packaged, categorized, and packed into some sort of container--usually 208-L (55-gal) drums--for shipment to waste-storage sites. Prior to shipment, the containers must be labeled, assayed, and certified; the assay value determines the ultimate disposition of the waste containers. An accurate nondestructive assay (NDA) method would identify all the radioisotopes present and provide a quantitative measurement of their activity in the drum. In this way, waste containers could be routed in the most cost-effective manner and without having to reopen them. Currently, the most common gamma-ray method used to assay nuclear waste drums is segmented gamma-ray scanning (SGS) spectrometer that crudely measures only the amount of {sup 235}U or {sup 239}Pu present in the drum. This method uses a spatially-averaged, integrated, emitted gamma-ray-intensity value. The emitted intensity value is corrected by an assumed constant-attenuation value determined by a spatially-averaged, transmission (or active) measurement. Unfortunately, this typically results in an inaccurate determination of the radioactive activities within a waste drum because this measurement technique is valid only for homogeneous-attenuation or known drum …

An aluminum piston tank has been developed for applications requiring lightweight, low cost, low pressure, positive-expulsion liquid storage. The 3 liter (183 in{sup 3}) vessel is made primarily from aluminum sheet, using production forming and joining operations. The development process relied mainly on pressurizing prototype parts and assemblies to failure, as the primary source of decision making information for driving the tank design toward its optimum minimum-mass configuration. Critical issues addressed by development testing included piston operation, strength of thin-walled formed shells, alloy choice, and joining the end cap to the seamless deep drawn can. 9 refs., 8 figs.

We compare angular distributions calculated by folding nucleon- nucleon scattering kernels, using the theory of Feshbach, Kerman and Koonin, and the systematics of Kalbach, with a wide range of data. The data range from (n,xn) at 14 MeV incident energy to (p,xn) at 160 MeV incident energy. The FKK theory works well with one adjustable parameter, the depth of the nucleon-nucleon interaction potential. The systematics work well when normalized to the hybrid model single differential cross section prediction. The nucleon- nucleon scattering approach seems inadequate. 9 refs., 10 figs.

The development of Inertial Confinement Fusion (ICF) as a power source will require demonstrating four principal objectives: ignition and propagating burn, adequate gain ({eta}G {approx gt} 10) at low drive energy for the reactor driver, reactor pulse rates of a few Hz, and the long-term reliability and economics of a reactor. Additionally, the potential value and applicability of special-purpose ICF reactors, such as tritium breeding reactors and reactors for burning high level fission waste (actinide and fission products) should be investigated. To keep development time and costs to a minimum these should be accomplished with as few major facilities as possible, and subsystems should be developed only as they are needed. A viable scenario for Inertial Fusion Energy (IFE) would include establishing the first milestone in the National Academy of Sciences (NAS) and Fusion Policy Advisory Committee (FPAC) recommended Nova Upgrade, and the latter three in an Engineering Test Facility (ETF)/Demonstration Power Plant (DPP), i.e. two major facilities. To be successful in so short a time, operations at the major facilities would have to be supported by off-line reactor driver and other technology development. The program plan discussed here assumes that enhanced funding is available beginning in FY 1992. It …

Argonne National Laboratory (ANL) and University of North Texas (UNT) research teams collected over 800 emissions and ash samples during the combustion of over 650 tons of binder enhanced densified refuse-drived fuel (b-dRDF) pellets with high sulfur coal in a spreader-stoker boiler at ANL. This full-scale test burn was conducted to validate predictions from laboratory and pilot scale test results that indicated substantial reductions of SO{sub 2}, NO{sub x} and CO{sub 2} in the flue gas, and the reduction of heavy metals and organics in the ash residue, when combusting the b-dRDF pellets with coal. Effects of varying fuel composition on performance of the boiler's spray-dryer/fabric filter emissions control system was also evaluated. This paper describes the b-dRDF pellet/coal cofiring tests, the emission and ash samples that were taken, the analyses that were conducted on these samples, and the final test results. 5 refs., 1 fig., 1 tab.

Parametric instabilities excited by an intense electromagnetic wave in a plasma is a fundamental topic relevant to many applications. These applications include laser fusion, heating of magnetically-confined plasmas, ionospheric modification, and even particle acceleration for high energy physics. In laser fusion, these instabilities have proven to play an essential role in the choice of laser wavelength. Characterization and control of the instabilities is an ongoing priority in laser plasma experiments. Recent progress and some important trends will be discussed. 8 figs.

We discuss various novel methods of frequency upshifting short ({le} 1 picosecond) pulses of laser light. All of these methods make use of either the sudden creation of a plasma or relativistic plasma waves. The first method discussed is known as photon acceleration. This method makes use of the fact that a laser pulse moving in a plasma can be thought of as a packet of photons, each possessing an effective mass of m{sub {gamma}} = {h bar}{omega}{sub pe}/c{sup 2} and moving with the group velocity of the laser pulse. These photons experience a force acting on them when in the presence of a gradient in the plasma density. By using a relativistic plasma wave (i.e., a moving density gradient) traveling with the photons, the energy of the photons (thus the frequency) can be continuously increased. We then discuss the sudden creation of a plasma in a region where there exists an electromagnetic wave. This results in a frequency shift of the wave. A similar method is the creation of an ionization front moving near the speed of light, whereby the interaction of this plasma front with an EM wave also results in a frequency upshift of the original wave. …

The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

LEED analysis of the clean annealed surface of a {l angle}110{r angle} oriented Pt{sub 3}Sn single crystal surface indicates the formation of a multilayer surface phase which does not have the L1{sub 2} bulk structure. LEISS analysis indicates a surface stoichiometry of ca. 1:1 with Sn atoms displaced ca. 1.4 above the plane of Pt atoms. The surface phase is hypothesized to be a rhombic distortion of the {l angle}0001{r angle} plant of PtSn, which has a B8{sub 1} (NiAs-type) bulk structure. It is not clear whether the phase forms by precipitation of PtSn due to a slight (0.5%) stoichiometric excess of Sn in the bulk, or due to multilayer reconstruction driven by surface segregation. 20 refs., 3 figs.

The study of rare and CP-violating B meson decays is well suited to a high-luminosity e{sup +} e{sup {minus}} collider. For studying certain decay processes there are also substantial benefits associated with asymmetric beam energies, which give a moving center of mass for the B mesons. We describe a design for a 9 GeV {times} 3.1 GeV B Factory in the PEP tunnel that would operate initially at a luminosity of 3 {times} 10{sup 33} cm{sup {minus}2}s{sup {minus}1}. Technical problems include issues related to high currents (e.g., beam instabilities, feedback systems, lifetime degradation and detector radiation power dissipation) and those related to the hetero-energetic beams (e.g., beam separation, beam-beam interaction and detector requirements). Issues requiring R D effort are identified. 8 refs., 2 figs., 2 tabs.

Recent developments in beam diagnostic equipment and measurement techniques have been driven by commercial technological advances, better data analysis algorithms, and the need to measure complex beam properties. The need for such developments is due to the increased diversity, beam intensity, and luminosity/brightness requirements of charged particle circular accelerators. In addition, the advent of fast analog-to-digital converters and cheap, powerful microprocessors have fundamentally changed the approach to beam diagnosis, allowing designers to create systems where signal processing is performed locally at each detector. New beam monitors from a wide variety of circular accelerators are reviewed. A number of interesting or innovative ideas are presented in detail. 56 refs.

The 10 m long ALS curved sector tank is formed from two shells out of which the beam chamber is machined. Vacuum pumping and photon stops are located in an antechamber connected to the beam tube through a 1cm slot. In order to determine whether the beam is significantly coupled to the antechamber, measurements of longitudinal beam impedance were performed up to 26 GHz, well above the cutoff frequency of the beam pipe. Two different schemes were used: In the first, the wire method was adapted for use above cutoff; in the second, the impedance was detected from the response to TM-waves propagated in the aperture without a wire. Temperature at various locations in the setup was recorded for later phase corrections. Antennas were placed in the antechamber to detect radiated power or possible resonances. A reference measurement was made with the slot sealed by a flexible gasket of knitted wire. The seal was then removed and the response with antechamber recorded. The response was checked by inserting obstacles of known impedance. Both measurement methods provided low numbers with Z/n<0.001 Ohm over the whole frequency range. No resonances attributable to the antechamber were observed. 3 refs., 6 figs.

Using rf pulse compression it will be possible to boost the 50- to 100-MW output expected from high-power microwave tubes operating in the 10- to 20-GHz frequency range, to the 300- to 1000-MW level required by the next generation of high-gradient linacs for linear for linear colliders. A high-power X-band three-stage binary rf pulse compressor has been implemented and operated at the Stanford Linear Accelerator Center (SLAC). In each of three successive stages, the rf pulse-length is compressed by half, and the peak power is approximately doubled. The experimental results presented here have been obtained at low-power (1-kW) and high-power (15-MW) input levels in initial testing with a TWT and a klystron. Rf pulses initially 770 nsec long have been compressed to 60 nsec. Peak power gains of 1.8 per stage, and 5.5 for three stages, have been measured. This corresponds to a peak power compression efficiency of about 90% per stage, or about 70% for three stages, consistent with the individual component losses. The principle of operation of a binary pulse compressor (BPC) is described in detail elsewhere. We recently have implemented and operated at SLAC a high-power (high-vacuum) three-stage X-band BPC. First results from the high-power three-stage BPC …

A series of multifilamentary APC Nb-Ti superconductors have been made with Nb added as a normal second phase to provide flux pinning centers. Two compositions, 12.5% vol % and 25 vol % Nb in Nb-Ti, have fabricated into multifilamentary composites using two different fabrication methods. One method used hot isostatic compaction and hot extrusion thoughout the processing. The other method (bundle-and-draw process) discontinued all hot processing at an intermediate level. While the J{sub c} values of the bundle-and-draw wires are quite promising, the critical current of the extruded wires appears to be limited by poor uniformity of the filament cross-sectional area along the conductor length. The large values of the index of the resistive transition and small filament standard-deviation-to-average area ratios observed in the wires produced by the bundle-and-draw process suggest extrinsic factors have little effect on J{sub c}. The variation in J{sub c} as the wire diameter is reduced appears to be most strongly affected by intrinsic factors: Nb distribution and pinning strength. The final filament microstructure and Nb spacing are shown to be difficult to calculate, e.g., the mean Nb spacing near the final wire size may be {1/2} to 1/3 that of the calculated value. 5 refs., …

The goal of COPS is to couple a program of regular observations to numerical models, through techniques of data assimilation, in order to provide a predictive capability for the US coastal ocean including the Great Lakes, estuaries, and the entire Exclusive Economic Zone (EEZ). The objectives of the program include: determining the predictability of the coastal ocean and the processes that govern the predictability; developing efficient prediction systems for the coastal ocean based on the assimilation of real-time observations into numerical models; and coupling the predictive systems for the physical behavior of the coastal ocean to predictive systems for biological, chemical, and geological processes to achieve an interdisciplinary capability. COPS will provide the basis for effective monitoring and prediction of coastal ocean conditions by optimizing the use of increased scientific understanding, improved observations, advanced computer models, and computer graphics to make the best possible estimates of sea level, currents, temperatures, salinities, and other properties of entire coastal regions.

Keeping pace with recent advances in construction technology is a challenge for the cost estimating engineer. Using an estimating style that simulates the actual construction process and is similar in style to the contractor's estimate will give a realistic view of underground construction costs. For a contractor-style estimate, a mining method is chosen; labor crews, plant and equipment are selected, and advance rates are calculated for the various phases of work which are used to determine the length of time necessary to complete each phase of work. The durations are multiplied by the cost or labor and equipment per unit of time and, along with the costs for materials and supplies, combine to complete the estimate. Variations in advance rates, ground support, labor crew size, or other areas are more easily analyzed for their overall effect on the cost and schedule of a project. 14 figs.