We report on two preliminary studies of color coherence effects on {ital p}{ital {anti p}} collisions based on data collected by the D{null} detector during the 1992-1993 and 1994-1995 runs at the Fermilab Tevatron collider at a center of mass energy {radical}s = 1. 8 TeV. Demonstration of initial-to-final state color interference effects is done in a higher energy region by measuring spatial correlations between the softer third jet and the second leading- {ital E}{sub {ital T}} jet in multi-jet events and in a lower energy regime by examining particle distribution patterns in W+Jet events. The data are compared to Monte Carlo simulations with different color coherence implementations and the predictions of an NLO parton level calculation.

Preliminary results from a search for the production of an associated lightest chargino, W{sub 1}, and second lightest neutralino, Z{sub 2}, pair with the D0 detector at Fermilab`s pp collider with {radical}s = 1.8 TeV are presented. Based on approximately 85 pb{sup -1} of data collected during the 1993-1995 Tevatron Runs we set a 95% C.L. upper limit on the chargino-neutralino cross section times branching fraction to any trileptonic final state ranging from 0.91 pb to 0.19 pb for wino masses ranging from 45 GeV/c{sup 2} to 96 GeV/c{sup 2}.

This paper reports the engine and vehicle simulation and analysis done at Lawrence Livermore (LLNL) as a part of a joint optimized hydrogen engine development effort. Project participants are: Sandia National Laboratory, California (SNLC), responsible for experimental evaluation; Los Alamos National Laboratory (LANL), responsible for detailed fluid mechanics engine evaluations, and the University of Miami, responsible for engine friction reduction. Fuel cells are considered as the ideal power source for future vehicles, due to their high efficiency and low emissions. However, extensive use of fuel cells in light-duty vehicles is likely to be years away, due to their high manufacturing cost. Hydrogen-fueled, spark-ignited, homogeneous-charge engines offer a near-term alternative to fuel cells. Hydrogen in a spark-ignited engine can be burned at very low equivalence ratios, so that NO{sub x} emissions can be reduced to less than 10 ppm without catalyst. HC and CO emissions may result from oxidation of engine oil, but by proper design are negligible (a few ppm). Lean operation also results in increased indicated efficiency due to the thermodynamic properties of the gaseous mixture contained in the cylinder. The high effective octane number of hydrogen allows the use of a high compression ratio, further increasing engine efficiency.

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies are often used in combination, and a trade-off exists between them. If window temperature is decreased, ventilation rate has to be increased. Reducing the ventilation rate requires an increase of the temperature of the windows to prevent condensation. An alternative solution is a desiccant dehumidifier, which adsorbs water vapor generated by the passengers. Window temperatures and ventilation …

The installation of a new intrusion detection system (IDS) is, of course, expected to improve site security. However, depending upon the way the system is used, it can, over time, actually degrade security. Proper use, control, and maintenance of the IDS is critical if site security is to be maintained. This paper discusses several operational issues that should be addressed in order to use an IDS effectively. Several anecdotes from the author`s experience are given to illustrate proper and improper use of an IDS. Improper operational use of an IDS can render it ineffective. Applying these tips can help keep the IDS operating at peak performance.

Exciting new safeguards and security technologies are on the horizon, and some are even on the shelves today. Self-testing sensors, smart sensors, and intelligent alarm analyzers are all designed to provide useful information to the operator. However, today`s current annunciator systems were not designed to accommodate these new technologies. New display technologies are also changing the look and feel of the annunciator of the future. Annunciator technology needs to ``catch up` to these other security technologies. This paper presents the concept for a new, object-oriented approach to annunciator architecture design. The new architecture could accommodate simple, switch-closure devices as well as information- rich sensors and intelligent analyzers. In addition the architecture could allow other leading-edge interfaces to be easily integrated into the annunciator system. These technologies will reduce operator workload and aid the operator in making informed security decisions. 3 refs., 2 figs.

Aquatic ecosystems are complex entities that are controlled and regulated by a multitude of physicochemical and biological processes. In addition, aquatic organisms experience a variety of natural and man-induced stressors, both of which vary spatially and temporally. The high variability in environmental factors combined with synergistic and cumulative interactions of these factors in aquatic ecosystems complicate the interpretation and evaluation of the effects of contaminant-related stressors on organisms. With this in mind, some main challenges facing those concerned with assessing the effects of environmental contaminants on organisms are (1) the influence of multiple stressors on stress responses in biological systems, (2) determining causal relationships between various levels of biological response to stressors, and (3) identifying early warning indicators or measures of organism impairment that have biological significance before irreversible or serious disability occurs. In all these areas, the health of biological systems (from the individual level to the population and community levels) has as its basis the physiological performance of the organism. Therefore, aspects of contaminant effects monitoring which include physiological measures of health should not only be utilized as measures of deviations from normal function, but should also be applied in the larger context of helping to understand multiple …

The performance of photovoltaic powered pumps in direct solar domestic hot water (PV-SDHW) systems has been studied. The direct PV- SDHW system employs a photovoltaic array, a separately excited DC- motor, a centrifugal pump, a thermal collector, and a storage tank. A search methodology for an optimum PV-SDHW system configuration has been proposed. A comparison is made between the long-term performance of a PV-SDHW system and a conventional SDHW system operating under three control schemes. The three schemes are: an ON-OFF flow controlled SDHW system operating at the manufacturer-recommended constant flow rate, and a linear proportional flow controlled SDHW system with the flow proportional to the solar radiation operating under an optimum proportionality. 13 refs., 6 figs.

Resistance degradation in PZT thin-film capacitors has been studied as a function of applied voltage, temperature, and film composition. It is found that the mean-time-to-failure (life-time or t{sub f}) of the capacitors shows a power law dependence on applied voltage of he form t{sub f} {proportional_to} V{sup {minus}n} (n {approximately} 4--5). The capacitor life-time also exhibits a temperature dependence of the form t{sub f} {proportional_to} exp(E{sub a}/kT), with an activation energy of {approximately} 0.8 eV. The steady-state leakage current in these samples appears to be bulk controlled. The voltage, temperature, and polarity dependence of the leakage current collectively suggest a leakage current mechanism most similar to a Frenkel-Poole process. The life-time and leakage current of the Nb-doped PZT films are superior to the undoped PZT films. This result can be explained based on the point-defect chemistry of the PZT system. Finally, the results indicate that the Nb-doped PZT films meet the essential requirements for decoupling capacitor applications.

The MACHO project is searching for dark qter inthe form of massive compact haio objects (Machos), by monitoring the brightness of millions of stars in the Magellanic Clouds to search for gravitational microlensing events. Analysis of our 1st 2.3 years of data for 8.5 million stars in the LMC yields 8 candidate microlensing events, well in excess of the {approx} 1 event expected from lensing by known low-mass stars. The event timescales range from 34 to 145 days, and the estimated optical depth is N 2x10{sup -7}, about half of that expected from a `standard` halo. Likelihood analysis indicates the typical lens mass is 0.5{sup +0.3}{sub -0.2}M{sub {circle_dot}}, suggesting they may be old white dwarfs.

Gamma ray effects are often neglected when evaluating reactor pressure vessel (RPV) embrittlement. However, recent analyses indicate that in newer style light water reactors, gamma damage can be a substantial fraction of the total displacement damage experienced by the (RPV); ignoring this damage will lead to errors in embrittlement predictions. Furthermore, gamma rays may be more efficient than fast neutrons at producing freely-migrating defects and as such can impact certain embrittlement mechanisms more effectively than fast neutrons. Consideration of these gamma effects are therefore essential for a more complete understanding of radiation embrittlement.

High-resolution TEM was carried out to determine shape and atomic arrangement of solid Xe precipitates in Al. Polycrystalline Al TEM specimens were implanted with 30 keV Xe{sup +} at RT to a dose of 3x10{sup 20} ions/m{sup 2} and then annealed at 523 K. Below a size 4 nm dia, the Xe precipitates are solid with an fcc crystal structure mesotacticly aligned with the Al lattice. In HRTEM along [011] projection, the difference in the lattice parameters of solid Xe and Al produces a precipitate image dominated by a 2-D Moire pattern that repeats in both the <001> and <111> directions every 3 Al (or 2 Xe) lattice spacings. Multi-slice image simulations, using a 3-D atomic model, demonstrates that the precipitates are tetradecahedra with faces parallel to the dense {l_brace}111{r_brace} planes and the {l_brace}100{r_brace} planes. Off-Bragg illumination of the precipitates minimizes Al lattice fringes and generates precipitate images which are in good agreement with the model.

The 400 MeV Fermilab Linac Upgrade commissioning began August 28, 1993. High energy physics collider operation (run 1b) began in November 1993 and ended March 1, 1996. The Linac, operating at 98% reliability, provided 400 MeV H{sup -} beam to the Booster and 66 MeV H{sup -} beam to the Neutron Therapy Facility. During this time, the beam intensity, which initially was administratively set to 35 MA, rose to a peak of 50 mA while losses decreased significantly. This paper discusses the Linac operation and reliability since the Upgrade.

The authors review recent progress in the description and understanding of disoriented chiral condensates. Certain important unsolved issues are underlined, and the preliminary results of the program of investigation of these issues in the framework of the classical linear sigma model are reported. They also briefly review a formalism which could be useful at the full non-equilibrium quantum field theory level of analysis.

We provide a mini-guide to some or the possible manifestations of weak scale supersymmetry. For each of six scenarios we provide: a brief description of the theoretical underpinnings, the adjustable parameters, a qualitative description of the associated phenomenology at future colliders, comments on how to simulate each scenario with existing event generators,

Metal Plasma Immersion Ion Implantation and Deposition (MePIIID) is a hybrid process combining cathodic arc deposition and plasma immersion ion implantation. The properties of metal plasma produced by vacuum arcs are reviewed and the consequences for MePIIID are discussed. Different version of MePIIID are described and compared with traditional methods of surface modification such as ion beam assisted deposition (IBAD). MePIIID is a very versatile approach because of the wide range of ion species and energies used. In one extreme case, films are deposited with ions in the energy range 20--50 eV, and at the other extreme, ions can be implanted with high energy (100 keV or more) without film deposition. Novel features of the technique include the use of improved macroparticle filters; the implementation of several plasma sources for multi-element surface modification; tuning of ion energy during implantation and deposition to tailor the substrate-film intermixed layer and structure of the growing film; simultaneous pulsing of the plasma potential (positive) and substrate bias (negative) with a modified Marx generator; and the use of high ion charge states.

Aluminum heavy liners of three basic types have been fabricated for Los Alamos pulse power experiments. The first fabrications used a conventional hand operated lathe with high speed steel cutting tools. More recent fabrications have used numerically controlled lathes with carbide insert cutting tools. A numerically controlled Pneumo lathe with an air bearing spindle and with air bearing cross slides has been used to fabricate the most recent examples of the 3.2 gm Pegasus Precision Liner that is normally accelerated to 3 mm/{micro}s for experiments at the Pegasus II pulse power facility. The basic dimensions, including wall thickness, of fourteen of these parts have been characterized by an automated inspection machine. Liner surface finishes are measured directly by stylus profilometer and by optical interferometric analysis of cast polymeric replicas. Statistics of these measurements will be presented. Plans for future fabrication of similar and larger liners with increasingly stringent specification of wall thickness and of surface finish are described along with corresponding plans for liner characterization improvements.

The US Department of Energy (DOE) uses sensitive or classified parts and material that must be protected and accounted for. The authors believe there is a need for an automated system that can help protect and monitor these parts and material. In response to this need Sandia National Laboratories (SNL) has developed a real-time personnel and material tracking system called PAMTRAK that has been installed at selected DOE facilities. PAMTRAK safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. This paper describes the goals when designing PAMTRAK, the PAMTRAK system components, the current installations, and the benefits a site can expect when using PAMTRAK.

Sensor technology for use in nuclear facility monitoring has reached and advanced stage of development. Research on where to place these sensors in a facility and how to combine their outputs in a meaningful fashion does not appear to be keeping pace. In this paper, we take a global view of the problem where sensor technology is viewed as only one piece of a large puzzle. Other pieces of this puzzle include the optimal location and type of sensors used in a specific facility, the rate at which sensors record information, and the risk associated with the materials/processes at a facility. If the data are analyzed off-site, how will they be transmitted? Is real-time analysis necessary? Are we monitoring only the facility itself, or might we also monitor the processing that occurs there? How are we going to combine the output from the various sensors to give us an accurate picture of the state of the facility? This paper will not try to answer all these questions, but rather it will attempt to stimulate thought in this area by formulating a systems approach to the problem demonstrated by a prototype system and a systems proposed for an actual facility. Our …

Evaluation of infrasonic detection capability for the International Monitoring System of the Comprehensive Test Ban Treaty (IMS/CTBT) is made with respect to signal analysis and global coverage. Signal analysis is anecdotally reviewed with respect to composite power, correlation and F-statistic detection algorithms. In the absence of adaptive pre-filtering, either cross-correlation or F-statistic detection is required. As an unbounded quantity, the F-statistic offers potentially greater sensitivity to signals of interest. With PURE state pre-filtering, power detection begins to become competitive with correlation and F-statistic detection. Additional application of simple post-filters of minimum duration and maximum bearing deviation results in unique positive detection of an identified impulsive infrasonic signal. Global coverage estimates are performed as a useful deterministic evaluation of networks, offering an easily interpreted network performance, which compliments previous probabilistic network evaluations. In particular, adequate coverage (2 sites), uniform coverage, and redundant coverage (3 to 4 sites) provide figures of merit in evaluating detection, location and vulnerability, respectively. Coverage estimates of the I60 network have been performed which indicate generally adequate coverage for the majority of the globe. Modest increase of station gain (increase of number of elements from 4 to 7) results in significant increase in coverage for mean signal …

Los Alamos National Laboratory has initiated a project to examine possible futures associated with the global nuclear enterprise over the course of the next 50 years. All major components are included in this study--weapons, nonproliferation, nuclear power, nuclear materials, and institutional and public factors. To examine key issues, the project has been organized around three main activity areas--workshops, research and analyses, and development of linkages with other synergistic world efforts. This paper describes the effort--its current and planned activities--as well as provides discussion of project perspectives on nuclear weapons, nonproliferation, nuclear energy, and nuclear materials focus areas.

The tight tolerances in the main linacs of the Nest Linear Collider (NLC) result in a large sensitivity of the beam emittance to slow alignment drifts. Once the accelerator is tuned, the optimized emittances must be maintained. Slow alignments drifts will make resteering and reoptimization necessary. The frequency of these linac reoptimizations is an important parameter that determines how well the linear collider can be operated. We present simulation results that address this question for the main linacs of the NLC. We will show that the effects of alignment drifts can indeed be handled.

Linear accelerators are the central components of the proposed next generation of linear colliders. They need to provide acceleration of up to 750 GeV per beam while maintaining very small normalized emittances. Standard simulation programs, mainly developed for storage rings, do not meet the specific requirements for high energy linear accelerators. The authors present a new program LIAR (LInear Accelerator Research code) that includes wakefield effects, a 4D coupled beam description, specific optimization algorithms and other advanced features. Its modular structure allows to use and to extend it easily for different purposes. They present examples of simulations for SLC and NLC.

Beamline stability is of great importance for future linear colliders where tolerances generally are in the micron to sub-micron range. A stretched wire system in the sealed FFTB tunnel at SLAC was used to monitor beamline motion with a sub-micron resolution. In future linear colliders low frequency changes of the beamline alignment (< 0.1 Hz) lead to untolerable quasistatical misalignments and betatron oscillations. Since it requires time to correct those errors, it is very important to determine how often corrections are needed. The authors present the measurements, discuss the systematics of the stretched wire system and compare the observations with the ATL-model for ground motion.