We calculated the signal and background rates for top masses of 90, 120, 150, and 180 GeV for both the CDF and D{null} detectors. This allowed us to determine the prospects for both discovery as well as detailed study of heavy top depending on the luminosity. We have focused on the leptons + jets and dilepton signatures. We also consider the question of tagging b-jets and how that should reduce background and help in making a mass determination. 8 refs., 5 figs., 5 tabs.

Brookhaven Experiment 802 (E-802) is a magnetic spectrometer experiment which is directed toward the measurement of particle momentum spectra and particle-particle correlations following reactions with 14.5 GeV/u O and Si ions. In addition to the spectrometer there are detectors to measure the transverse energy flow, longitudinal energy flow, and the multiplicity. These detectors can be used to characterize the particle spectra or correlated between themselves. Particle spectra have been obtained for protons, pions, and kaons using targets of gold, copper, and aluminum although the data are not entirely analyzed as yet. A first result that is of interest is the K/sup +//..pi../sup +/ ratio for Si + Au reactions which is larger than expected on the basis of the known p + p data. 4 refs., 11 figs.

In a national laboratory setting, it is necessary to provide radiation protection overview and training to diverse parts of the laboratory population. This includes employees at research reactors, accelerators, waste facilities, radiochemical isotope processing, and analytical laboratories, among others. In addition, our own radiation protection and monitoring staffs must be trained. To assist in the implementation of this full range of training, ORNL has purchased prepackaged computer-based training in health physics and technical mathematics with training modules that can be selected from many topics. By selection of specific modules, appropriate radiation protection review packages can be determined to meet many individual program needs. Because our radiation protection personnel must have some previous radiation protection experience or the equivalent of an associate's degree in radiation protection for entry level, the computer-based training will serve primarily as review of major principles. Others may need very specific prior training to make the computer-based training effective in their work situations. 4 refs.

This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and high catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. The work is focused on the elucidation of coal-catalyst precursor interactions in solution and the variables which control the adsorption and dispersion of coal gasification metal catalysts. In order to optimize coal-metal ion interactions and hence maximize catalyst activity, the study examines the surface electrochemistry of a lignite, a subbituminous, and a bituminous coals and their demineralized and oxidized derivatives prior to loading with the catalytic materials. The surface electrical properties of the coals are investigated with the aid of electrophoresis, while the effects of the surface charge on the adsorption of K{sup +} and Ca{sup 2+} are studied by agitating the coals with aqueous solutions of potassium and calcium. A zeta meter, a tube furnace, and other equipment required for the investigation have been acquired and installed. Preliminary work shows that the …

At the Savannah River Plant, the separations areas are not equipped with automated accountability systems, therefore accountability is performed manually. Several years ago, the Computer Systems Engineering group was requested to develop a computerized accountability system for the separations areas that would rely on manual entry and perform the necessary computations, adjust and maintain the books, and generate the necessary reports. In addition, the system would provide a complete audit trail and help reduce operator errors. Since the separations areas are actually divided into several material balance areas, the Computer Systems Engineering group was faced with several detailed specifications. Rather than designing a computerized accountability system for each material balance area, they designed a generic system that each area could tailor to its process. The system helps in reducing operator errors by displaying simple data entry forms, performing data validations when possible, providing field help, performing all computations, and generating the necessary reports. Many validation tables are user configurable, as well as the equations for computing transfer and inventory values. 8 figs.

There is general recognition that engineering issues are critical to the viability of liquid argon calorimetry (LAC) at the Superconducting Super Collider (SSC). We have undertaken to quantitatively address these issues and, if possible, perform a preliminary design of a proof of principle'' LAC for SSC. To establish LAC as viable at SSC, we must demonstrate that the physics performance of the device is acceptable, despite the presence of dead material due to vessels and support structure. Our approach involves the construction, by a team of physicists and engineers, of one three dimensional model of the LAC system, built as a hierarchy of components and structures, from which we directly perform interferences checks, mechanical, thermal and magnetic analyses, particle tracking, hermeticity evaluation, physics simulation and assembly. This study, begun in February 1989 as part of the SSC generic detector R and D program, was immediately preceded by a workshop at which engineering details of existing and planned LAC systems were thoroughly examined. We describe below the status of our work, beginning with short descriptions of the tools used, the study requirements and LAC configuration baseline. We then detail the LAC design as it presently stands, including assembly considerations, and conclude …

We are in the process of developing and commissioning a scanning photoelectron microscope (SPEM) at the X1A beamline of the National Synchrotron Light Source (NSLS). It is designed to make use of the Soft X-ray Undulator (SXU) at the NSLS. This high brightness source illuminates a Fresnel zone plate, which forms a focused probe, {<=} 0.2{mu}m in size, on the specimen surface. A grating monochromator selects the photon energy in the 400-800 eV range with an energy resolution of better than 1 eV. The expected flux in the focus is in the 5 {times} 10{sup 7} {minus} 10{sup 9} photons/s range. A single pass Cylindrical Mirror Analyzer (CMA) is used to record photoemission spectra, or to form an image within a fixed electron energy bandwidth as the specimen is mechanically scanned. As a first test, a 1000 mesh Au grid was successfully imaged with a resolution of about 1{mu}m and the CMA tuned to the Au 4 f photoelectron peak. Once it is commissioned, a program is planned which will utilize the microscope to study beam sensitive systems, such as thin oxide/sub-oxide films of alumina and silica, and ultimately various adsorbates on these films. 14 refs., 4 figs.

We describe instrumentation of a scanning photoelectron microscope (SPEM), which we are presently developing and commissioning at the X1A beamline of the National Synchrotron Light Source (NSLS). This instrument is designed to use the Soft X-ray Undulator (SXU) at the NSLS as a high brightness source to illuminate a Fresnel zone plate, thus forming a finely focused probe, {le} 0.2{mu}m in size, on the specimen surface. A grating monochromator selects the photon energy in the 400-800 eV range with an energy resolution better than 1 eV. The expected flux in the focus is in the 5 {times} 10{sup 7} {minus} 10{sup 9} photons/s range. A single pass Cylindrical Mirror Analyzer (CMA) is used to record photoemission spectra, or to form an image within a fixed electron energy bandwidth as the specimen is mechanically scanned. As a first test, a 1000 mesh Au grid was successfully imaged with Au 4 f primary photoelectrons, achieving a resolution of about 1{mu}m. 10 refs., 5 figs., 1 tab.

Because the goal of emergency preparedness for both chemical and nuclear hazards is to reduce human exposure to hazardous materials, this paper examines the interchange of lessons learned from emergency planning and accident experience in both industries. While the concerns are slightly different, sufficient similarity is found for each to draw implications from the others experience. Principally the chemical industry can learn from the dominant planning experience associated with nuclear power plants, while the nuclear industry can chiefly learn from the chemical industry's accident experience. 23 refs.

Decomposition of nitromethane is reported over the range of 115- 180/degree/C and 0.6-8.5 GPa. About 5 /mu/g of nitromethane is compressed with a diamond-anvil cell, heated to the point that reaction occurs, and held typically 10-20 minutes at the reaction temperature. The cell is cooled and the volatile contents of the cell are frozen as a thin layer in vacuo and an infrared absorption spectrum is recorded. The three volatile products observed are N/sub 2/O, CO/sub 2/, and water, with N/sub 2/O production peaking at 1.5 GPa, 135/degree/C, and 35% of NME; CO/sub 2/ production peaking at 3.5 GPa, 135/degree/C, and 65% of NME, and water yields at 20-50% of NME at the highest pressure measured, 8.5 GPa and 175/degree/C. Water yields were difficult to quantify due to background contamination. Results indicate three different reactions for solid NME dependent primarily on the pressure of the reaction, and that fluid NME does not decompose at 0.6 GPa and 175/degree/C, although the solid decomposes readily at 1.1 GPa and 120/degree/C. The authors conclude that, while various decomposition mechanisms are possible, the initial step CH/sub 3/NO/sub 2/ /yields/ /center dot/CH/sub 3/ + /center dot/NO/sub 2/ is very unlikely. 14 refs., 5 figs.

Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N{approximately}134, Z{approximately}88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin {approximately}8{Dirac h}. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin {approximately}7{Dirac h}. The nuclei which exhibit octupole deformation in this mass region are {sup 144}Ba, {sup 146}Ba and {sub 146}Ce; {sup 142}Ba, {sup 148}Ce, {sup 150}Ce and {sup 142}Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab.

Partial level schemes for several neutron-rich Ba and Ce nuclei have been determined from the study of gamma-gamma coincidences in /sup 252/Cf fission fragments. The experiment was performed with the Argonne-Notre Dame gamma ray facility, which consisted of 7 Compton- suppressed Ge detectors, a low-energy photon spectrometer and an inner ball of fourteen hexagonal BGO detectors. Gamma-gamma coincidence events between the Ge detectors, which were accompanied by a gamma in BGO detectors, were accepted. The triple coincidence requirement eliminated most of the beta-decay background. Transitions in individual Ba and Ce nuclei were identified by gating on the known 2/sup +/ ..-->.. O/sup +/ gamma rays. Level schemes deduced from these studies indicate interleaved negative and positive parity levels in /sup 144/Ba, /sup 146/Ba and /sup 146/Ce which are connected by fast E1 transitions. Both these features are signature of octupole deformation (reflection asymmetric shape) and are reproduced by recent theoretical calculations. 4 refs., 1 fig., 1 tab.

A number of studies have shown that selective attention to spatial location modulates the amplitudes of several visual evoked potential components recorded from posterior regions of the head (e.g., Eason, Harter White, 1969; Harter, Aine, Schroeder, 1982; Hillyard Munte, 1984; Mangun Hillyard, 1988). The early components, P1 and N1 (peak latencies: 90--135 and 140--170 msec, respectively), are thought to arise in one or more areas of visual cortex. Although it is generally assumed that such ERP effects reflect differential activation of populations of neurons at successive levels of the nervous system, little information is available about the neural structures responsible for such effects. We have employed neuromagnetic techniques in an attempt to identify more precisely the neural structures involved in selective attention to spatial location within the P1-N1 time sequence. In this study, effects of attention were assessed by comparing neural responses evoked by stimuli at a specified spatial location when subjects were required to attend and respond behaviorally to that location with neural responses to the same stimuli when subjects were required to attend and respond behaviorally to another location in the visual field. 7 refs., 3 figs.

Neuromagnetic measurements and associated modeling procedures must be able to resolve multiple sources in order to localize and accurately characterize the generators of visual evoked neuromagnetic activity. Workers have identified at least 11 areas in the macaque, throughout occipital, parietal, and temporal cortex, which are primarily or entirely visual in function. The surface area of the human occipital lobe is estimated to be 150--250cm. Primary visual cortex covers approximately 26cm/sup 2/ while secondary visual areas comprise the remaining area. For evoked response amplitudes typical of human MEG data, one report estimates that a two-dipole field may be statistically distinguishable from that of a single dipole when the separation is greater than 1--2 cm. Given the estimated expanse of cortex devoted to visual processes, along with this estimate of resolution limits it is likely that MEG can resolve sources associated with activity in multiple visual areas. Researchers have noted evidence for the existence of multiple sources when presenting visual stimuli in a half field; however, they did not attempt to localize them. We have examined numerous human MEG field patterns resulting from different visual field placements of a small sinusoidal grating which suggest the existence of multiple sources. The analyses we …

A search was made in 29 GeV e/sup +/e/sup /minus// annihilations for massive neutrinos decaying to e/sup +-/X/sup /minus plus//(..nu..) where X is a muon or meson. A 300 pb/sup /minus/1/ data sample yielded just one candidate event with a mass m/sub ex/ > 1.8 GeV. Significant limits are found for new neutrinos with masses from 1.8 to 6.7 GeV and with mixing parameters in the range 10/sup /minus/6/ < chemically bondUchemically bond/sup 2/ < 1. 12 refs., 4 figs.

Research continued on the conversion of synthesis gas to alcohols and reactor configuration. Objectives for this quarter: the project stated on October 1, 1989 and according to the Task Schedule provided in the original work breakdown schedule, Task I was to be completed in the first quarter and Task II to be started. Task I consisted of construction of the slurry reactor set-up to be used in Task IV for determination of the reactor kinetics and procurement of the parts for automation equipment, separators, computer activated parts etc. for automation of the trickle bed rector and GC equipment. Task II consisted of standardization and automation of GC analysis protocols. 1 fig.

Heats of detonation of CHNO explosives correlate well with copper cylinder test expansion data. The detonation products/calorimetry data can be used to estimate performance in the cylinder test, in munitions, and for new molecules or mixtures of explosives before these are made. Confidence in the accuracy of the performance estimates is presently limited by large deviations of a few materials from the regression predictions; but these same deviations, as in the insensitive explosive DINGU and the low carbon systems, appear to be sources of information useful for detonation and explosives research. The performance correlations are functions more of the detonation products and thermochemical energy than they are of the familiar parameters of detonation pressure and velocity, and the predictions are closer to a regression line on average than are those provided by CJ calculations. The prediction computations are simple but the measurements (detonation calorimetry/products and cylinder experiments) are not. 17 refs., 5 tabs.

Data from 200 A GeV /sup 16/O + (C, Au) reactions are presented. The local fluctuations in the pseudo-rapidity density charged particles were studied with the method of scaled factorial moments. The extracted moments, <F/sub i/>, are found to be proportional to a power of the size of the pseudo-rapidity interval, /delta//eta/. Slopes were determined from the linear relation ln<F/sub i/> = a/sub i/ /minus/ /phi//sub i/ln/delta//eta/ and their dependence on impact parameter and multiplicity of charged particles are shortly discussed. 10 refs., 3 figs.

Current oil well perforation techniques use low- to medium-velocity gun launchers for completing wells in soft rock. Shaped-charge jets are normally used in harder, more competent rock. A device to create a much higher velocity projectile was designed. This launcher will provide an alternative technique to be used when the conventional devices do not yield the maximum well performance. It is an adaptation of the axial cavity in a high explosive (HE) annulus design, with the axial cavity being filled with a low density foam material. Two configurations were tested; both had an HE annulus filled with organic foam, one had a projectile. Comparison of the two shots was made. A time sequence of Image Intensifier Camera photographs and sequential, orthogonal flash x-ray radiographs provided information on the propagation of the foam fragments, the first shock wave disturbance, the projectile motion and deformation, and the direct shock wave transmission from the main HE charge. DYNA2D calculations were made to assist in the experimental interpretation. 25 refs., 9 figs.

We present the development of a diffusion accelerated Sn transport method for the solution of temperature coupled radiation flow problems on a spatial mesh of arbitrary quadrilaterals in R-Z geometry. The diffusion acceleration equation is derived from the diamond-like transport spatial discretization. The effectiveness of the DSA method is shown on an example calculation and also computation times are indicated. 3 refs., 3 figs.

The standard first collision source method is modified to include the angle-integrated, mesh cell balance equation. This modification produces a method that is fully consistent with our normal S/sub N/ balance which is essential for diagnostic purposes. The method is also second order in mesh refinements. Illustrative results are also presented in the paper. 3 refs., 5 figs., 1 tab.

In the fall of 1988, the 750 keV Cockcroft-Walton (C-W) preinjector for the AGS 200 MeV H/sup /minus// linac was replaced by an RFQ, in what has proved to be a very successful upgrade. The motivations for the upgrade included improved reliability, simpler maintenance, and the added convenience of having the ion source located at nearly ground potential. At the same time, the controls and instrumentation in the preinjector area were modernized. The linac has been operating full time with this RFQ preinjector since January 1, 1989, and the reliability has been excellent. The source, RFQ, and linac operate at a 5 Hz repetition rate, and the beam pulse width is approximately 450 ..mu..s. At this time, the H/sup /minus// current at 200 MeV is typically 23-25 mA, the same as previous operation with the C-W, although the capability is there to reach higher currents in the future. The layout of the new preinjector is shown in Figure 1. An important consideration in the layout of this line was the decision to leave the final 2.4 m section before the linac intact, so the optics of a second C-W injector line and polarized H/sup /minus// injection from another RFQ remained …

A current of 30 mA has been extracted from a volume production H{sup {minus}} source having a toroidal discharge chamber and rotational symmetry. This is a current density of 30 mA/cm{sup 2}. The emittance measurement gave a normalized, 90% value of {epsilon} {sub N}(90%) = 0.32 {pi} mm-mrad for a 13 mA beam. The ion temperature is estimated to be 0.57 eV for this case. For 25.5 mA, {epsilon} {sub N}(90%) = 1.11 {pi} mm-mrad was measured, but the true value is most likely smaller due to a limitation in the emittance resolution. 6 refs., 4 figs., 1 tab.

Three nominally 25-mm (1-in) thick shielded metal-arc welds were prepared from 304L base plate with 308 filler material, to obtain three different ferrite levels (4, 8, and 12 %). Portions of these welds were then aged at 343/degree/C for 3000, 10000, and 20000 hours. Charpy V-notch and tensile specimens were taken from the welds. The tensile results were similar for all the specimens and showed little effect of aging on either the yield or ultimate tensile strengths. The Charpy impact properties of the higher ferrite content materials were significantly degraded by these agings, with larger decreases in the impact energy with increased aging time. The microstructures of the welds were examined by metallography and transmission electron microscopy, and the fracture surfaces were examined by scanning electron microscopy. The changes in the mechanical properties and the fractography are discussed in light of the observed changes in the microstructure. 3 refs., 3 figs., 2 tabs.