Single-particle inclusive cross sections of precisely identified fragments are studied together with associated multiplicities of fast charged particles. Neon and argon projectiles are made to bombard uranium, calcium, and aluminium. It is found that all the observed fragment spectra are structureless and more or less exponentially decaying throughout the range of studied fragment masses. A catalogue of experimentally found qualitative features is given and the applicability of simple statistical thermodynamic models is examined by tracing down in the spectra kinematical effects in the framework of a source of a temperature and a velocity, leading to a nuclear fireball model. The production of complex particles is also discussed. A simple mass dependence in the cross section of the fragments is observed. The possibilities of a struck projectile and the explosion of a compound nucleus are considered. 7 references. (JFP)

Among the various energy options opened to man, fusion appears particularly attractive since fuel is plentiful, cheap, and universally available, the reaction is self quenching, produces in itself no radioactive wastes and radiation hazards are minimum. However, creating on earth conditions emulating the sun is not as easy task. Two significantly different approaches to obtaining the necessary conditions are being actively pursued and both have shown encouraging progress in the past few years. Magnetic confinement will be discussed in the next paper. Inertial confinement fusion is progressing towards scientific breakeven in the 1980's. High yield targets have been successfully imploded proving the feasibility of thermonuclear burn. High densities have recently been achieved using glass lasers as drivers. Power plants using fusion sources are being studied and could become operational in the early 2000's.

Transfer factors to predict the environmental transport of radionuclides through terrestrial foodchains to man were derived from the literature for radionuclides associated with the nuclear fuel cycle. We present updated transfer coefficients to predict the concentration of a radionuclide in cow's milk and other animal products and concentration factors (CF) to predict the concentration in a food or feed crop from that in soil. Where possible we note the variation of the transfer factor with physical and chemical form of the radionuclide and environmental factors, and characterize the distribution and uncertainty in the estimate. The updated transfer factors are compared with those listed in regulatory guides. The new estimates lead to recommended changes (both increases and decreases) in the listed transfer coefficients for milk and meat and to the suggested practice of adopting multiple soil-to-plant CF's that vary with the type of crop and soil in the place of a single generic CF to predict the concentration of a radionuclide in a crop from that in soil. The updated transfer factors will be useful to assess the dose from radionuclides released from nuclear facilities and evaluating compliance with regulations governing the release of radionuclides.

The AERIN computer code is a mathematical expression of the ICRP Lung Model. The code was developed at the Lawrence Livermore National Laboratory to compute the body organ burdens and absorbed radiation doses resulting from the inhalation of transuranic isotopes and to predict the amount of activity excreted in the urine and feces as a function of time. Over forty cases of internal exposure have been studied using the AERIN code. The code, as modified, has proven to be extremely versatile. The case studies presented demonstrate the excellent correlation that can be obtained between code predictions and observed bioassay data. In one case study a discrepancy was observed between an in vivo count of the whole body and the application of the code using urine and fecal data as input. The discrepancy was resolved by in vivo skull counts that showed the code had predicted the correct skeletal burden.

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.

An article clipping from The Dallas Morning News article 'A rosier picture' written by Larry Bleiberg. The piece covers the planned rebuilding of the Dallas ISD fine arts program through several years of revamped funding and building up of curriculum.

High statistics W charge asymmetry measurements at the Tevatron {bar p}p collider significantly constrain the u and d quark distributions, and specifically the slope of the d(x)/u(x) in the x range 0.007 to 0.27. The authors present measurements of lepton charge asymmetry as a function of lepton rapidity, A(y{sub l}) at {radical}s = 1.8 TeV for {vert_bar}y{sub l}{vert_bar} < 2.0, for the W decays to electrons and muons recorded by the CDF detector during the 1992-93 run ({approx} 20 pb{sup {minus}1}), and the first {approx} 50 pb{sup {minus}1} of data from the 1994-95 run. These precise data make possible further discrimination between sets of modern parton distributions. In particular it is found that the most recent parton distributions, which included the CDF 1992-93 W asymmetry data in their fits (MRSA, CTEQ3M and GRV94) are still in good agreement with the more precise data from the 1994-95 run. W charge asymmetry results from D0 based on {approx} 6.5 pb{sup {minus}1} data from 1992-1993 run and {approx} 29.7 pb{sup {minus}1} data from 1994-1995 run, using the W decays to muons, are also presented and are found to be consistent with CDF results. In addition, the authors present preliminary measurement of the Drell-Yan …

In 1946, President Harry Truman, in a document currently on display at the entrance to this auditorium, approved a directive to the National Academy of Sciences-National Research Council (NAS-NRC) to initiate a long-term investigation of the health effects associated with exposure to radiation from the atomic bombs. With funding provided by the Atomic Energy Commission, now the Department of Energy, NAS-NRC established the Atomic Bomb Casualty Commission (ABCC) in March 1947. The government of Japan through the Japanese National Institute of Health, became a partner in that endeavor in 1948. In 1975, the Radiation Effects Research Foundation (RERF) was established and assumed the responsibilities of ABCC. This symposium commemorates 50 years of ABCC/RERF. It is dedicated to the many survivors and their families without whose cooperation we would not have learned as much as we have about the effects of radiation. It is also dedicated to the thousands of employees of RERF and scientists around the world who have contributed through the years to the analysis and interpretation of the information emerging from this unique study.

Concepts for producing tritium in an accelerator were translated into hardware for engineering studies of tritium generation, heat transfer, and effects of proton-neutron flux on materials. Small-scale target- blanket assemblies were fabricated and material samples prepared for these performance tests. Blanket assemblies utilize composite aluminum-lead modules, the two primary materials of the blanket. Several approaches are being investigated to produce large-scale assemblies, developing fabrication and assembly methods for their commercial manufacture. Small-scale target-blanket assemblies, designed and fabricated at the Savannah River Site, were place in Los Alamos Neutron Science Center (LANSCE) for irradiation. They were subjected to neutron flux for nine months during 1996-97. Coincident with this test was the development of production methods for large- scale modules. Increasing module size presented challenges that required new methods to be developed for fabrication and assembly. After development, these methods were demonstrated by fabricating and assembling two production-scale modules.

Three-dimensional high-resolution simulations are performed of the Richtmyer- Meshkov (RM) instability for a Mach 6 shock, and of the passage of a second shock from the same side through a developed RM instability. The second shock is found to rapidly smear fine structure and strongly enhance mixing. Studies of the interaction of moderately strong shocks with a pre-existing turbulent field indicate amplification of transverse vorticity and reduction Of stream-wise vorticity, as well as the mechanisms for these changes.

We have designed a target to probe the use of the Pegasus Z-Pinch machine to image inertial instabilities that develop on cylindrical- convergent material interfaces. The Z-pinch is tailored so that the target, soft Al 1100-O, remains solid; instabilities and inertial effects are seeded by wire inclusions of different densities. We present here the first images and preliminary results from this experiment.

Determination of low-molecular-weight organic sulfonates (e.g. taurine and cysteic acid) in aqueous solutions is important in many applications of biological, environmental and pharmaceutical sciences. These compounds are difficult to be determined by commonly used reversed-phase liquid chromatographic separation combined with UV-Visible detection because of their high solubility and the lack chromophoric moieties. Here the authors report a method combining ion-pair liquid chromatography and electrospray ionization tandem mass spectrometry (IPLC/ESI-MS/MS)for determining sulfonates. The ability of low-molecular-weight sulfonates to form ion-pairs with quaternary ammonium cations in aqueous solutions allowed LC separation with a C{sub 18} column. Detection of the sulfonates was accomplished with ESI-MS that lends a universal mode of mass detection for polar, water soluble compounds. An in-source collision induced dissociation (CID) was applied to eliminate the adduct peaks in mass spectra. Characteristic marker ions showed in the second stage mass spectra lent a method for identifying sulfonates.

Failure mechanisms under tensile loading of unidirectional fiber composites comprising of Weibull fibers embedded in a matrix are studied using Monte-Carlo simulations. Two fundamental mechanisms of failure are recognized--stress concentration driven failure and strength driven failure. It is shown that the cumulative distribution function for composite strength predicted by the stressconcentration-driven failure and strength-driven failure form apparent upper and lower bounds respectively and also that failure mechanism switches from one to the other as fiber strength variability changes.

Investigations into several areas of research have been undertaken to address the performance limitations of the toroid analyzer. The Simion 3D6 (2) ion optics simulation program was used to determine whether the potential well minimum of the toroid trapping field is in the physical center of the trap electrode structure. The results (Figures 1) indicate that the minimum of the potential well is shifted towards the inner ring electrode by an amount approximately equal to 10% of the r0 dimension. A simulation of the standard 3D ion trap under similar conditions was performed as a control. In this case, the ions settle to the minimum of the potential well at a point that is coincident with the physical center (both radial and axial) of the trapping electrodes. It is proposed that by using simulation programs, a set of new analyzer electrodes can be fashioned that will correct for the non- linear fields introduced by curving the substantially quadrupolar field about the toroid axis in order to provide a trapping field similar to the 3D ion trap cross- section. A new toroid electrode geometry has been devised to allow the use of channel- tron style detectors in place of the more …

The thermal conductivity and structural properties of polycrystalline and single crystal semiconductor type-1 germanium clathrates are reported. Germanium clathrates exhibit thermal conductivities that are typical of amorphous materials. This behavior occurs in spite of their well-defined crystalline structure. The authors employ temperature dependent neutron diffraction data in investigating the displacements of the caged strontium atoms in Sr{sub 8}Ga{sub 16}Ge{sub 30} and their interaction with the polyhedral cages that entrap them. Their aim is to investigate the correlation between the structural properties and the low, glass-like thermal conductivity observed in this compound.

Leak-path factors (LPFs) were calculated for the Nuclear Materials Storage Facility (NMSF) located in the Plutonium Facility, Building 41 at the Los Alamos National Laboratory Technical Area 55. In the unlikely event of an accidental fire powerful enough to fail a container holding actinides, the subsequent release of oxides, modeled as PuO{sub 2} aerosols, from the facility and into the surrounding environment was predicted. A 1-h nondestructive assay (NDA) laboratory fire accident was simulated with the MELCOR severe accident analysis code. Fire-driven air movement along with wind-driven air infiltration transported a portion of these actinides from the building. This fraction is referred to as the leak-path factor. The potential effect of smoke aerosol on the transport of the actinides was investigated to verify the validity of neglecting the smoke as conservative. The input model for the NMSF consisted of a system of control volumes, flow pathways, and surfaces sufficient to model the thermal-hydraulic conditions within the facility and the aerosol transport data necessary to simulate the transport of PuO{sub 2} particles. The thermal-hydraulic, heat-transfer, and aerosol-transport models are solved simultaneously with data being exchanged between models. A MELCOR input model was designed such that it would reproduce the salient features …

The formation of adducts among analyte species is a well known phenomenon in electrospray ionization mass spectrometry (ESI-MS). The presence of salts usually promotes the formation of adducts by electrostatic and van de waalse bonds among various ions present in solution. In this study, the authors describe a simple mathematical model to explain the patterns for mass distribution and peak intensity for adducts formed by magnesium chloride and various fatty acid anions.

Propagation of a fire that originates in a single glovebox to other locations in the Plutonium Facility at Los Alamos National Laboratory is conceivable only if transport of hot combustion gases to other locations causes ignition of combustible materials elsewhere in the system (i.e., flashover). This paper describes a model developed, using the MELCOR computer code, to calculate the generation and transport of combustion gas mass and energy during postulated glovebox fire accident scenarios. The accident scenarios involved a wide spectrum of glovebox operating and potential fire conditions to determine whether flashover conditions could occur at locations outside the burning glovebox: o A variety of combustible material characteristics was considered (e.g., type, quantity, and combustion properties of combustible material). o A spectrum of safety system operating conditions was considered (e.g., glovebox ventilation system operating normally vs an inoperative exhaust fan; drop-box fir e damper closure vs failure to close). o A range of analytical modeling assumptions was considered (e.g., the extent to which heat transfer between hot combustion gases and the glovebox walls is represented in the model). Example results of these calculations are presented to illustrate the benefits obtained and lessons learned by using a computational tool like MELCOR …

Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described.

The objectives of this work were to evaluate the consequences of a postulated accident to onsite security personnel stationed near the facility during operations of the Godiva IV critical assembly and to identify controls needed to protect these personnel in case of an extreme criticality excursion equivalent to the design-basis accident (DBA). This paper presents the methodology and results of the source-term calculations, building ventilation rates, air concentrations, and consequence calculations that were performed using a multidisciplinary approach with several phenomenology models. Identification of controls needed to mitigate the consequences to near-field receptors is discussed.

American National Standard ANSI/ANS-8.12-1987 (Ref. 1) was approved for use on September 11, 1987, The history of the development of the standard is discussed in Ref. 2. The first version of this standard, which included subcritical limits only on homogeneous plutonium-uranium fuel mixtures, was approved July 17, 1978. The current version was revised to add limits on heterogeneous systems (Ref., 3). This paper provides additional information on the limits presented in the standard.

In the first stage of Run II, the Tevatron will be operated with 36 bunches in each beam with bunch separations of 396 nanoseconds. The expected peak luminosity is L = 8.6 x 10{sup 31}cm{sup {minus}2}sec{sup {minus}1} with an average number of 2.3 interactions per bunch crossing. In the second stage of Run II, the goal is to increase the luminosity to about 1.5x10{sup 32} cm{sup {minus}2}sec{sup {minus}1}. If the bunch spacing were kept constant, the average number of interactions per bunch crossing would increase to about 4. This is thought to be unacceptably large and might saturate the efficiency of the detectors. This is the main reason for decreasing the bunch spacing at higher luminosities. One possibility is to reduce the bunch spacing to 132 nanoseconds which lowers the average number of interactions to an acceptable value of 1.4. This shorter bunch spacing though has several consequences on beam dynamics. Collisions between bunches will now occur every 19.78m. This is shorter than the distance of the nearest separators from the main IPs at B0 and D0. Consequently the beams will not be separated at the parasitic collisions nearest to the IPs if the geometry of the orbit is left …

We present initial characterization data from a new single line of sight (SLOS) x-ray framing camera. The instrument uses an image dissecting structure inside an electron optic tube to produce up to four simultaneous DC images from a single image incident on the cathode and a microchannel plate based device to provide the temporal gating of those images. A series of gated images have been obtained using a short pulse UV laser source, and the spatial resolution of those images is compared to those obtained using a more traditional MCP based system.

Control of rotation in tokamak plasmas provides a method for suppressing fine-scale turbulent transport by velocity shear and for stabilizing large-scale magnetohydrodynamic instabilities via a close-fitting conducting shell. The experimental discovery of rotation in a plasma heated by the fast-wave minority ion cyclotron process is important both as a potential control method for a fusion reactor and as a fundamental issue, because rotation arises even though this heating process introduces negligible angular momentum. This paper proposes and evaluates a mechanism which resolves this apparent conflict. First, it is assumed that angular momentum transport in a tokamak is governed by a diffusion equation with a no-slip boundary condition at the plasma surface and with a torque-density source that is a function of radius. When the torque density source consists of two separated regions of positive and negative torque density, a non-zero central rotation velocity results, even when the total angular momentum input vanishes. Secondly, the authors show that localized ion-cyclotron heating can generate regions of positive and negative torque density and consequently central plasma rotation.