We describe the design and performance of a detector system for tracking charged particles in an environment of high track density and rates up to 1 MHz. The system operates in the forward spectrometer of the BNL Heavy Ion experiment E814 and uses principles of general interest in high rate, high multiplicity applications such as at RHIC or SSC. We require our system to perform over a large dynamic range, detecting singly charged particles as well as fully ionized relativistic {sup 28}Si. Results on gas gain saturation, {delta}-ray suppression, and overall detector performance in the presence of a 14.6 GeV/nucleon {sup 28}Si beam and a 14 GeV proton beam are presented. 6 refs., 9 figs.

The effect of Au on the reliability of 0.65 mm pitch surface mount solder joints between plastic quad flat packs and Cu-Ni-Au FR-4 printed circuit boards was investigated. Cu-Ni-Au is a desirable printed circuit board finish for multi-chip modules or printed circuit boards that would otherwise require a selective Au finish, for example for edge connectors or wire bondable parts. However, Au is known to embrittle solder when it is present in sufficiently high concentrations, creating a concern that solder joint fatigue life in service will also be adversely affected. This paper reports the results of mechanical shock, mechanical vibration and thermal cycling testing of fine pitch solder joints containing varying amounts of Au. Tests were performed on as-soldered joints and on joints that had been heat-treated to evolve the microstructure toward equilibrium. The tests were designed to accelerate in-service conditions in a typical industrial environment. Under these conditions, the Au concentrations tested did not promote solder joint failures. Microstructural characterization of the distribution and morphology of the Au-, Ni-, and Cu-Sn intermetallics in the joint before and after accelerated testing was also performed. On the basis of these observations it is recommended that the Au concentration in solder joints …

Resonant ultrasound spectroscopy is used to measure the temperature dependence of all six elastic moduli of La{sub 2-x}Sr{sub x}CuO{sub 4}. A giant softening (> 50% reduction) in the in-plane shear modulus, c{sub 66}, is observed and is attributed to the tetragonal-orthorhombic structural phase transition in this material. This phase transition and the corresponding softening is examined with a simple anharmonic mechanical model and a macroscopic Ginsburg-Landau formalism exploiting the full symmetry of the crystal. 16 refs., 5 figs.

The LIFE2 computer code is a fatigue/fracture analysis code that is specialized to the analysis of wind turbine components. The numerical formulation of the code uses a series of cycle mount matrices to describe the cyclic stress states imposed upon the turbine. However, many structural analysis techniques yield frequency-domain stress spectra and a large body of experimental loads (stress) data is reported in the frequency domain. To permit the analysis of this class of data, a Fourier analysis module has been added to the code. The module transforms the frequency spectrum to an equivalent time series suitable for rainflow counting by other modules in the code. This paper describes the algorithms incorporated into the code and uses experimental data to illustrate their use. 10 refs., 11 figs.

We have searched for the reaction e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f, where f is either an electron, muon, or charged pion, at {radical}s = 29 GeV using the Mark 2 detector at the PEP storage ring. One candidate event is found while 2.3 events are expected from known processes. We would expect to see 11 events if the cross-section for e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f at {radical}s = 29 GeV were enhanced by the factor of 4.7 which the ALEPH collaboration reports for {radical}s = 91 GeV. we also look for e{sup +}e{sup {minus}} {yields} e{sup +}e{sup {minus}}{bar f}f and e{sup +}e{sup {minus}} {yields} {mu}{sup +}{mu}{sup {minus}} {bar f}f, and for e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}} {gamma} using a similar analysis procedure and see the number of events predicted by the standard model. 10 refs., 5 figs., 3 tabs.

Triplets composed of superconducting quadrupoles have been built and installed as the final focusing element for the high-energy positron and electron beams of the SLAC Linear Collider. Special features include independent alignment to 100-micron tolerance inside a common cryostat; non-magnetic materials to allow operation inside the detector's solenoid field; a continuous-flow helium-only system using 50-meter-long flexible transfer lines; and complete operation of the system before installation. The mechanical design and cryogenic operation experience are presented.

Magnetic field measurements have been made on twelve 17 m-long, 40 mm-aperture R D superconducting dipoles. Data on dipole field strength, multipole coefficients, and alignment have been obtained. The data indicate that the magnets as built are generally within the expectations for this design. 7 refs., 5 figs.

The use of dileptons as probes of hot, dense hadronic matter is described. Preliminary results on dileptons produced in p-p and p-d interactions at the Bevalac are presented along with potential ramifications for existing model calculations of dileptons at these energies. Future directions of the dilepton program at Berkeley are outlined. 14 refs., 3 figs.

The Savannah River Site (SRS) has been operating a nuclear fuel cycle since the 1950's to produce nuclear materials in support of the national defense effort. About 83 million gallons of high level waste produced since operation began have been consolidated into 33 million gallons by evaporation at the waste tank farm. The Department of Energy has authorized the construction of the Defense Waste Processing Facility (DWPF) to immobilize the waste as a durable borosilicate glass contained in stainless steel canisters, prior to emplacement in a federal repository. The DWPF is now mechanically complete and undergoing commissioning and run-in activities. Cold startup testing using simulated non-radioactive feeds is scheduled to begin in November 1992 with radioactive operation scheduled to begin in May 1994. While technical issues have been identified which can potentially affect DWPF operation, they are not expected to negatively impact the start of non-radioactive startup testing.

A novel full scale production reactor fuel assembly model was designed and built to study thermal-hydraulic effects of postulated Savannah River Site (SRS) nuclear reactor accidents. The electrically heated model was constructed to simulate the unique annular concentric tube geometry of fuel assemblies in SRS nuclear production reactors. Several major design challenges were overcome in order to produce the prototypic geometry and thermal-hydraulic conditions. The two concentric heater tubes (total power over 6 MW and maximum heat flux of 3.5 MW/m{sup 2}) (1.1E+6 BTU/(ft{sup 2}hr)) were designed to closely simulate the thermal characteristics of SRS uranium-aluminum nuclear fuel. The paper discusses the design of the model fuel assembly, which met requirements of maintaining prototypic geometric and hydraulic characteristics, and approximate thermal similarity. The model had a cosine axial power profile and the electrical resistance was compatible with the existing power supply. The model fuel assembly was equipped with a set of instruments useful for code analysis, and durable enough to survive a number of LOCA transients. These instruments were sufficiently responsive to record the response of the fuel assembly to the imposed transient.

In Karkow, Poland almost half of the energy used for heating is supplied by local, solid-fuel-fired boilerhouses and home stoves. These facilities are referred to as the low emission sources'' and are primary contributors of particulates and hydrocarbon air pollution in the city and secondary contributors of sulfur dioxide and carbon monoxide. The Support of Eastern European Democracy Act of 1989 directed the US Department of Energy to undertake an equipment assessment project aimed at developing the capability within Poland to manufacture or modify industrial-scale combustion equipment to utilize fossil fuels cleanly. The Project is being conducted in a manner that can be generalized to all of Poland and uito the rest of Eastern Europe. The project plan includes three phases which have been developed around five specific subprojects. In Phase 1, technical and economic assessments will be made of pollution reduction options for the five subprojects. Phase 2 plans call for public meetings in the US and Poland for companies interested in forming joint ventures. Information will be available in these meetings to enable companies to identify markets and select potential partners that meet with their capabilities and interests. In Phase 3, DOE will issue a solicitation for Polish/American …

Conventional soldering of electronic components generally requires the application of a chemical flux to promote solder wetting and flow. Chlorofluorocarbons (CFC) and halogenated solvents are normally used to remove the resulting flux residues. While such practice has been routinely accepted throughout the electronics industry, the environmental impact of hazardous solvents on ozone depletion will eventually limit or prevent their use. Solvent substitution or alternative technologies must be developed to meet these goals. Sandia National Laboratories, Albuquerque has a comprehensive environmentally conscious electronics manufacturing program underway that is funded by the DOE Office of Technology Development. Primary elements of the integrated task are the characterization and development of alternative fluxless soldering technologies that would eliminate circuit board cleaning associated with flux residue removal. Storage and handling of hazardous solvents and mixed solvent-flux waste would be consequently reduced during electronics soldering. This paper will report on the progress of the SNL fluxless soldering initiative. Emphasis is placed on the use of controlled atmospheres, laser heating, and ultrasonic soldering.

The results of high-temperature creep of various ceramic composites will be reviewed. In particular, creep results for Al{sub 2}O{sub 3} and Si{sub 3}N{sub 4} matrices reinforced with SiC whiskers will be emphasized. For a given temperature, stress and grain size, the creep rate of the Al{sub 2}O{sub 3} composite is usually lower than that of the ceramic matrix. In general, creep at low stresses occurs by grain boundary sliding accommodated by diffusion, whereas higher stresses lead to damage accumulation processes which are manifested by triple point cavitation and cracking. The quasi-steady-state creep rates depend on grain size, whisker concentration, and the amount of glass phase present between the boundary of the whisker and the matrix. Unless all of the parameters are known, including the fabrication and loading histories, comparisons between various studies that used samples prepared in different ways are difficult. 44 refs., 7 figs., 2 tabs.

The mechanical resonances of small oriented single crystals of materials of interest to basic science and engineering can be used to determine all the elastic moduli and the ultrasonic attenuation of these materials. To measure the resonances of the samples without introducing the resonances of the measuring system requires that the transducers be non-resonant at the frequencies of interest, and that they be well isolated from their mounts. However, for samples near 1 mm in the largest dimension, the transducer design problem becomes sever, and the signals become weak. In addition, no resonances can be missed, and, often, the symmetry class of the resonances must be known. We outline here appropriate transducer, electronics, and system designs to circumvent these problems. 10 refs., 4 figs.

Weld hot cracking of stainless steels is a major materials-related problem in the welding industry. This present investigation evaluates the crack susceptibility of highly-constrained EB welds made in materials whose DeLong ferrite potentials range from zero to nine FN. In addition, the effect of piece part strength level on cracking is examined. This study has revealed that these deep penetration EB welds have regions that solidify as primary austenite, even when the DeLong ferrite potential is as high as 9 FN. This points out the critical role that solidification rate plays in the crack susceptibility of these highly restrained welds. In addition, 0 FN to 0 FN welds had primarily transverse cracks while 6 FN to 0 FN welds had primarily centerline cracks. Of particular interest is the observation that cracks still occur if a high ferrite (greater than 6 FN) component is welded to a zero FN component. Cracking is always associated with regions which solidify as primary austenite and these cracks occur because there are areas in the weld which do not mix. Thus it is not a recommended production practice to compensate for low ferrite in one piece part with high ferrite in its mate. Finally, it …

This paper describes the application of a three-dimensional, global-scale Eulerian model with an explicit description of cloud and chemical processes. Simulation results describing the transport of sulfur from North America and Europe across the north Atlantic Ocean during a climatological July are presented. Wet deposition was found to contribute slightly more to total sulfur deposition than dry deposition, a feature explained by the large amounts of precipitation during this month. The wet deposition patterns did not always correspond to the emissions patterns. The precipitation rate and spatial distribution had a large effect on the calculated concentrations of soluble sulfur species. 10 refs., 7 figs., 1 tab.

Validation issues in aging risk evaluations are examined by considering how variabilities and uncertainties due to sparse component aging data, modeling assumptions, and risk quantification approaches may affect aging risk evaluation results and inferences. Sensitivity studies using a NUREG-1150 PWR evaluated the effect of component aging data uncertainties and variations in test and maintenance frequencies on aging prioritizations. Preliminary results indicate that while individual component rankings may be sensitive to aging data uncertainties, the top contributors as a group are not easily affected. Aging prioritizations seem to be quite sensitive to component test and maintenance frequencies. The results of the sensitivity study will help identify prioritization schemes which are robust and meaningful for applications.

Like most large networked sites our users depend heavily on the electronic mail system for both internal and off-site communications. Unfortunately the sendmail.cf file, which is used to control the behavior of the sendmail program, is somewhat cryptic and difficult to decipher for the neophyte. So, on one hand you have a highly visible, frequently used utility, and on the other hand a not-so-easily acquired system administration forte. Here is the sendmail topology of our site, what premises we based it on, and the parts of the sendmail.cf files which support the topology.

Observations of heavy ion interactions at the highest available accelerator energies provide essential information for the analysis and interpretation of cosmic ray interactions. We report on an experiment in which emulsion chamber detectors were exposed to beams of 200A GeV {sup 32}S ions at the CERN SPS. We present statistical features of pseudorapidity distributions from central collisions in the experimental sample and compare them with the predictions from the Lund Model (FRITIOF) which contains only conventional physics. 8 refs., 3 figs.

In order to examine the effect of irradiating particle species on the growth rate of radiation-induced dislocation loops, a solution-annealed Fe-25Ni-15Cr-0.02C alloy was irradiated at 723 K first by 1.5 MeV Kr{sup +} ions for 2520 sec, then by 1.5 MeV Kr{sup +} ions and 1.0 MeV electrons simultaneously for 780 sec, and finally by 1.0 MeV electrons for 780 sec with the HVEM-Tandem Facility in Argonne National Laboratory. The calculated damage rate by 1.5 MeV Kr{sup +} ions was 5.8 {times} 10{sup {minus}4} dpa/s, and that by 1.0 MeV electrons was 1 {times} 10{sup {minus}4} dpa/s. The growth rate of a dislocation loop located at the center of the specimen was 7 {times} 10{sup {minus}3} nm/s for the Kr{sup +} ion irradiation, 4 {times} 10{sup {minus}2} nm/s for the simultaneous Kr{sup +} and electron irradiation, and (2--3) {times} 10{sup {minus}2} nm/s for the electron irradiation. This implies that the electron irradiation is about 19 times more effective in the growth of radiation-induced dislocation loops than the Kr{sup +} ion irradiation. The dislocation loop growth rate under the simultaneous Kr{sup +} and electron irradiation is higher than the sum of the growth rates under the individual Kr{sup +} and electron …

Eleven 17 m long, 40 mm aperture SSC R D superconducting collider dipole magnets, built at BNL, have been extensively tested at BNL and Fermilab during 1990--91. Quench performance of these magnets and details of their mechanical behavior are presented. 7 refs., 5 figs.

Several Los Alamos National Laboratory (LANL) object-oriented discrete-event simulation efforts have been completed during the past three years. One of these systems has been put into production and has a growing customer base. Another (started two years earlier than the first project) was completed but has not yet been used. This paper will describe these simulation projects. Factors which were pertinent to the success of the one project, and to the failure of the second project will be discussed (success will be measured as the extent to which the simulation model was used as originally intended). 5 figs.

As we approach the 21st century, sentiments run high in the US for improved air quality in our cities and for a more secure energy future, hopefully to be manifest in lesser dependence on foreign supplies of oil. These sentiments are reflected in intense political activity on both the federal and state levels to enact legislation that will help alleviate both problems. At the same time though, the recent emergence of awareness of a threat of global warming due to ever increasing emissions of greenhouse gases has only served as an additional complicating factor, one which has not been fully dealt with either socially or politically in the US. Much discussion and deliberation on the issue of the greenhouse effect is underway in the US and aimed at understanding the size of the problem as well as identifying options for solutions. This paper will review the recent political climate on issues of environment and energy and will include brief descriptions of the recent US Clean Air Act Amendments, the California Clean Air Act, the National Energy Strategy, and the Alternative Motor Fuels Act of 1988. These policies and programs form a backdrop for the additional and more recent challenges brought …

We have developed two general approaches to the stereoselective synthesis of {sup 15}N- and {sup 13}C-labeled amino acids. First, labeled serine, biosynthesized using the methylotrophic bacterium M. extorquens AM1, serves as a chiral precursor for the synthesis of other amino acids. For example, pyridoxal phosphate enzymes can be used for the conversion of L-({alpha}-{sup 15}N)serine to L-({alpha}-{sup 15}N)tyrosine, L-({alpha}-{sup 15}N)tryptophan, and L-({alpha}-{sup 15}N)cysteine. In the second approach, developed by Oppolzer and Tamura, an electrophilic amination'' reagent, 1-chloro-1-nitrosocyclohexane, was used to convert chiral enolates into L-{alpha}-amino acids. We prepared 1-chloro-1-({sup 15}N) nitrosocyclohexane and used it to aminate chiral enolates to produce L-({alpha}-{sup 15}N)amino acids. The stereoselectivity of this scheme using the Oppolzer sultam chiral auxiliary is remarkable, producing enantiomer ratios of 200 to 1. 22 refs., 4 figs.