Within the past few months two excellent summaries sup{(1,2)} of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation; the question of the neutral currents, and the weak equivalence principle.

Fine axial flutes enhance heat transfer in vertical shell-and-tube exchangers with water inside the tubes and ammonia evaporating or condensing in layer flow on the shell side. Single-tube experiments with R-11 and ammonia indicate local shell-side coefficients 3 to 5 times those for corresponding smooth tubes. Single-tube experiments with water indicate that at moderate velocities the tube-side coefficients are enhanced by a factor equal to the ratio of fluted-to-smooth surface areas while the fluid friction is similarly increased. The experimental data are transformed into mean individual coefficients for ammonia and water. Overall coefficients for a particular case are presented to illustrate the efficacy of enhancement by flutes on one or both sides of the heat transfer surface. Means are described for using emerging data to predict the static and dynamic behavior of the power cycle and the interactions of components throughout the complete power plant.

Two approaches to enhancement of the Q (energy gain) factor of mirror systems are under study at Livermore. These include the Tandem Mirror and the Field Reversed Mirror. Both of these new ideas preserve features of conventional mirror systems as far as plasma-wall interactions are concerned. Specifically in both approaches field lines exit from the ends of the system and impinge on walls located at a distance from the confinement chamber. It is possible to predict some aspects of the plasma/surface interactions of TM and FRM systems from experience obtained in the Livermore 2XIIB experiment. In particular, as observed in 2XIIB, effective isolation of the plasma from thermal contact with the ends owing to the development of sheath-like regions is to be expected. Studies presently underway directed toward still further enhancing the decoupling of the plasma from the effects of plasma surface interactions at the walls will be discussed, with particular reference to the problem of minimizing the effects of refluxing secondary electrons produced by plasma impact on the end walls.

To avoid the effects of fluid instabilities, stringent requirements must be imposed on the surface quality and wall thickness uniformity of fuel pellets used in Inertial Confinement Fusion compression experiments. A systematic method was developed for specifying the type of defects which must be avoided and for evaluating measurement techniques for their suitability for detecting these defects. A review is given of the techniques currently available and those under development to show the relationship between these capabilities and the current and future requirements for pellet uniformity. The speed of these techniques and the implications for automated production of fuel pellets for a reactor are discussed.

GRPANL (GRouP ANaLysis) is a general-purpose peak fitting program that first determines gamma-ray and x-ray energies and intensities for specified peaks or clusters of peaks in a spectrum and then proceeds to interpret these results, determining both the radioisotopes detected and the amounts of each in the sample. Versions of the program are now running on the Digital Equipment Corporation (DEC) VAX and PDP-11 computers. The code has several unique capabilities for deconvoluting and interpreting difficult analytical situations that other codes usually cannot handle.

The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

Following the accident at the nuclear reactor at Chernobyl, in the Soviet Union on April 26, 1986, we performed a variety of measurements to determine the level of the radioactive fallout on the western United States. We used gamma-spectroscopy to analyze air filters from the areas around Lawrence Livermore National Laboratory (LLNL), California, and Barrow and Fairbanks, Alaska. Milk from California and imported vegetables were also analyzed. The levels of the various fission products detected were far below the maximum permissible concentration levels.

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for …

The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for …

CIRCE is an efficient beam dynamics code developed to facilitate the design and analysis of heavy-ion accelerators. The code combines an envelope description of the beam transverse dynamics with a fluid-like treatment of longitudinal dynamics, and terms are included to account for the effects of space charge, emittance, and image forces. CIRCE is currently being adapted to model the Induction Linac Systems Experiments (ILSE) facility, a proposed heavy-ion accelerator designed to test aspects of an inertial-fusion driver. The numerical model in the code is discussed, and changes needed for modeling ILSE are outlined. Preliminary work is presented on beam matching along the ILSE lattice and on transport around the ILSE achromatic bend.

Ultra-shallow, box-like impurity profiles are produced using Gas Immersion Laser Doping (GILD) and then analyzed by spreading resistance profilometry (SRP) and secondary ion mass spectrometry (SIMS) to determine the impurity distribution. At high concentrations, the profiles obtained by SRP exhibit the expected box-like shape over the entire range of junction depths: The measured concentration within the junction region is uniform while the dopant gradient at the junction exceeds 0.5 decades/nm. In comparison, the same profiles analyzed by SIMS show a broader transition at the metallurgical junction. Caused by knock-ons and ion mixing during the sputtering process, this inaccuracy is reduced, but not eliminated by lowering the acceleration energy of the primary Cs{sup +} ion beam. At lower concentrations (< 10{sup 19}/cm{sup 3}), profiles analyzed by SRP exhibit shallower junctions than expected. Electrical measurements of diodes and Hall structures show that high-quality, ultra-shallow n{sup +}p, np and pn are fabricated with good dose control using GILD. For complete characterization of GILD, accurate measurement of both chemical and electrically-active dopant profiles are required. At present, neither SIMS nor SRP provides an entirely accurate impurity profile.

This report describes utilization of multilayer mirrors and beam splitters to develop x-ray laser interferometry, radiography, and deflectometry to probe high-density laser plasmas.

This paper briefly summarizes requirements of site characterization for Natural Phenomena Hazards (NPH) at DOE sites. In order to comply with DOE Order 5480.28, site characterization criteria has been developed to provide site-specific information needed for development of NPH assessment criteria. Appropriate approaches are outlined to ensure that the current state-of-the-art methodologies and procedures are used in the site characterization. General and detailed site characterization requirements are provided in the areas of meteorology, hydrology, geology, seismology and geotechnical studies.

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One of the primary objectives of the Fall 1997 IOP was to intercompare Ka-band (35GHz) and W-band (95GHz) cloud radar observations and verify system calibrations. During September 1997, several cloud radars were deployed at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site, including the full time operation 35 GHz CART Millimeter-wave Cloud Radar (MMCR), (Moran, 1997), the University of Massachusetts (UMass) single antenna 33GHz/95 GHz Cloud Profiling Radar System (CPRS), (Sekelsky, 1996), the 95 GHz Wyoming Cloud Radar (WCR) flown on the University of Wyoming King Air (Galloway, 1996), the University of Utah 95 GHz radar and the dual-antenna Pennsylvania State University 94 GHz radar (Clothiaux, 1995). In this paper the authors discuss several issues relevant to comparison of ground-based radars, including the detection and filtering of insect returns. Preliminary comparisons of ground-based Ka-band radar reflectivity data and comparisons with airborne radar reflectivity measurements are also presented.

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Millimeter-wave rf cavities for use in linear accelerators, free-electron lasers, and mm-wave undulatory are under development at Argonne National Laboratory. Typical cavity dimensions are in the 1000 mm range, and the overall length of the accelerator structure, which consists of 30-100 cavities, is about 50-100 mm. An accuracy of 0.2% in the cavity dimensions is necessary in order to achieve a high Q-factor of the cavity. To achieve this these structures are being fabricated using deep X-ray lithography, electroforming, and assembly (LIGA). The first prototype cavity structures are designed for 108 GHz and 2p/3-mode operation. Input and output couplers are integrated with the cavity structures. The cavities are fabricated on copper substrates by electroforming copper into 1-mm-thick PMMA resists patterned by deep x-ray lithography and polishing the copper down to the desired thickness. These are fabricated separately and subsequently assembled with precision spacing and alignment using microspheres, optical fibers, or microfabricated spacers/alignment pieces. Details of the fabrication process, alignment, and assembly work are presented in here.

A source of instability in the western Pacific warm pool is shown to be due to sea surface elevation variations caused by changes in the zonal sea-surface temperature (SST) gradient and the changes in the Pacific Ocean basin length in relation to the warm pool latitudinal location. The variation of the sea-surface elevation is measured by using the thermocline depth response calculated from a two-layer ocean. The warm pool is shown to be barely at equilibrium during the boreal late winter and early spring by comparing the measured thermocline at 110{degree}W, 0{degree}E with the calculated thermocline depth. Based on this analysis, a failure or reversal of the climatological zonal winds are apparently not a necessary precursor for the instability of the warm pool and initiation of a warm event. A warm event can be initiated by an increase in the size of the warm pool and/or an increase in zonal SST differences during the boreal/winter spring. This mechanism could be an alternate mechanism for El-Nino Southern Oscillation (ENSO) dynamics to that postulated by Bjeknes (1969).

We have extracted polarized nucleon distributions from recent data at CERN, SLAC and DESY. The flavor-dependent valence and sea quark spin distributions are determined for each experiment. We take into account possible differences in the up and down sea distributions, and assume that the strange sea contribution is suppressed by mass effects. Physics results determined from different experiments are compared, including higher order corrections.

A single column model (SCM) is, in essence, an isolated grid column of a general circulation model (GCM). Hence, SCMs have rather demanding input data requirements, but do not suffer from problems associated with balance of a GCM. Among the initial conditions that must be used to describe the initial state of the SCM column are the vertical profile of the horizontal wind components and the vertical profiles of cloud water and ice. In addition, the large-scale divergence and advective tendencies of cloud water and ice must be supplied as external parameters. Finally, the liquid and ice cloud amount as a function of height within the SCM column are required for model evaluation. The scale of the SCM column over which the initial conditions, external parameters, and model evaluation fields must apply is relatively large ({approximately}300 km). To quantify atmospheric structure on this scale, the ARM SGP CART site is located within the NOAA wind profiler network and has boundary and extended measurement facilities in an area compatible with the scale requirements of SCMs. Over an area this size, however, there is often rich mesoscale structure. This mesoscale variability creates a sampling problem that can thwart even the most sophisticated …

This paper focuses on the lessons learned during the decontamination and decommissioning (D and D) of two reactors at Argonne National Laboratory-East (ANL-E). The Experimental Boiling Water Reactor (EBWR) was a 100 MW(t), 5 MSV(e) proof-of-concept facility. The Janus Reactor was a 200 kW(t) reactor located at the Biological Irradiation Facility and was used to study the effects of neutron radiation on animals.

The (La{sub 1{minus}} x Sr{sub x}){sub 3}Mn{sub 2}O{sub 7} compounds are layered materials that exhibit higher magneto-resistance than the corresponding 3D manganite perovskites. Quasi-elastic neutron scattering on a polycrystalline sample of La{sub 1.4}Sr{sub 1.6}Mn{sub 2}O{sub 7} shows that the spin fluctuation spectrum of the these layered CMR materials is qualitatively similar to those found in the perovskite manganites (La,Ca)MnO{sub 3}; their concentration, lifetime, and coherence length increase as T decreases to T{sub c}. Unlike the perovskites we find a lower spin-diffusion constant above T{sub c} of {approximately}5 meV {angstrom}{sup 2}.

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