We are investigating the interactive process between turbulent flow and dispersed phase particles. We are focusing on the mechanisms that appear to result in a reduction of local turbulent intensity and a corresponding reduction in wall heat transfer and subsequent wall erosion in turbulent solid propellant combustion flow. We apply computational simulations and physical experiments specialized to a developing free shear layer over a rearward facing step and over a parallel splitter plate. The flow configuration evolves in a two-dimensional, steady, combustion and non-combustion turbulent free shear mixing region, with and without particle additives. The computational simulations combine three basic components: gas phase Navier-Stokes solutions, Lagrange particle field solutions and a Monte Carlo technique for the random encounters, forces and accelerations between the two fields. We concentrate here on relatively large sized additive particles (of the order of tens of microns to 100 microns mean diameter). We examine their apparent influence in breaking up the larger, energy bearing eddy structures into smaller structures which are more readily dissipated.

The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

This paper describes the results of a program conducted at Sandia National Laboratories (SNL) for the US Department of Energy to provide an experimental data base for more accurately assessing the radiological consequences from a hypothetical sabotage attack on a spent fuel shipping cask. The primary objectives of the program were limited to: (1) evaluating the effectiveness of selected high explosive devices (HED) in breaching full-size spent fuel casks, (2) quantifying and characterizing relevant aerosol properties of the released fuel, and (3) using the resulting experimental data to evaluate the radiological health consequences resulting from a hypothetical sabotage attack on a spent fuel shipping cask in a densely populated area. Subscale and full-scale experiments in conjunction with an analytical modeling study were performed to meet the programmatic objectives. The data from this program indicate that the Urban Studies greatly overestimated the impact of malevolent acts directed at spent fuel casks in urban environs. From that standpoint this work could be the basis of additional regulatory revisions of the NRC physical protection requirements. In a larger sense this work can also be the basis of more credible worst case analyses since it defines the actual result of an event which is …

In laser driven inertial confinement fusion research, at Livermore, we are diagnosing many phenomena that occur in a time frame that exceeds the capabilities of even the most advanced, present day oscillographic recording instruments. Many of the by-products of the interaction between the laser beam and fuel pellet are monitored to determine the specifics of the fusion process. By the use of appropriate detectors, we convert the information contained in the radiated by-products to electrical signals which are recorded on high bandwidth oscillographic recorders. Our present range of recording capabilities for one x-ray diagnostic measurement in use at Livermore is shown. A commonly used configuration consists of an XRD-31 x-ray detector connected to a direct access Tektronix R7912 transient digitizer using 1/2 in. diameter air dielectric coaxial cable. This configuration gives a system fwhm of approximately 335 ps. Our premier configuration, on the other hand, consists of an improved response detector and a French Thomson-CSF TSN-660 oscilloscope with a shorter length of coaxial cable (typically 20 feet). The system fwhm in this case is less than 120 ps which is our fastest oscillographic recording system at the present time.

The diagnostic data from the MTX experiment is acquired and processed by an expandable, distributed, multivendor computer network. The system blends a variety of software into a coordinated, unified, and highly flexible design. Using modular software design techniques, we created a system stressing distributed processing, portability, and transparent data access. In our approach to modularity, we standardized communication interfaces between modules and separated generic tasks from machine and application-specific implementations. For flexible distributed processing, we used modular, portable software and LLNL facility that provides an interprocess communication system (IPCS) in the multivendor network. With transparent data access, any program can access data stored anywhere in the network without knowing the specific location. The computer hardware includes a DEC VAX cluster, HP workstations and HP desktop computers. We are using commercial software in addition to packages from MIT, ORNL, and LLNL. 4 refs., 4 figs.

A neutrino detector at the Brookhaven AGS has been used to investigate the feasibility of using an already constructed apparatus for GUT monopole searches. A flux limit (90%CL) of 5.2 x 10/sup -12/ cm/sup -2/ sec/sup -1/ str/sup -1/ was found. The limitations of such an approach are discussed.

The ECRH diagnostics system monitors the net power delivered to the plasma by four 200-kW gyrotron oscillators, the frequency of each gyrotron, and some operating parameters of the gyrotron power supply system. The combination CAMAC- and GPIB-based data acquisition system is under desktop computer control that provides the capability for data conversion and display. The data acquisition system is also interfaced to the main computer system that acquires and archives the data.

There are new requirements emerging in the field of tomography: the need for spatial resolution in the micrometre range, atomic species specificity, and quantitative density discrimination.

Searching for neutrinoless double beta decay is the only known practical method for trying to determine whether neutrinos are their own antiparticles. The theoretical motivation for supposing that they may indeed be their own antiparticles is described. The reason that it is so difficult to ascertain experimentally whether they are or are not is explained, as is the special sensitivity of neutrinoless double beta decay. The potential implications of the observation of this reaction for neutrino mass and for the physics of neutrinos is discussed.

Recent measurements of nonsolar isotopic patterns for the elements neon and (perhaps) magnesium in cosmic rays are interpreted within current models of stellar nucleosynthesis. One possible explanation is that the stars currently responsible for cosmic-ray synthesis in the Galaxy are typically super-metal-rich by a factor of two to three. Other possibilities include the selective acceleration of certain zones or masses of supernovas or the enhancement of /sup 22/Ne in the interstellar medium by mass loss from red giant stars and planetary nebulas. Measurements of critical isotopic ratios are suggested to aid in distinguishing among the various possibilities. Some of these explanations place significant constraints on the fraction of cosmic ray nuclei that must be fresh supernova debris and the masses of the supernovas involved. 1 figure, 3 tables.

The group considered physics, accelerator, and polarized source issues. Most of the physics study was concerned with what significant and unique experiments could be done if polarized protons could be accelerated in the main injector and eventually in the Tevatron. 12 refs., 4 figs.

Refined nuclear analysis, including the treatment of resonance and spatial self-shielding, coupled with an optimization procedure, has resulted in improved performance estimates for two conceptual fission-suppressed blankets. Net specific breeding in these two blankets maximized at 0.024 and 0.023 U-233 atoms/MeV, which is about an order of magnitude higher than in fission breeders.

Advanced wave models used to evaluate ICRH in tokamaks typically use warm plasma theory and allow inhomogeneity in one dimension. The majority of these calculations neglect the fact that gyrocenters experience the inhomogeneity via their motion parallel to the magnetic field. The non-local effects of rotational transform and toroidicity can play a significant role in both the propagation and the absorption physics. In strongly driven systems, wave damping can distort the particle distribution function supporting the wave and this produces changes in the absorption. The most common approach is to use Maxwellian absorption rates. We have developed a bounce-averaged Fokker-Planck quasilinear computational model which evolves the population of particles on more realistic orbits. Each wave-particle resonance has its own specific interaction amplitude within any given volume element; these data need only be generated once, and appropriately stored for efficient retrieval. The wave-particle resonant interaction then serves as a mechanism by which the diffusion of particle populations can proceed among neighboring orbits. The local specific spectral energy absorption rate is directly calculable once the orbit geometry and populations are determined. The code is constructed in such fashion as to accommodate wave propagation models which provide the wave spectral energy density on …

Results are presented from Fermilab E-400 on the production of charmed baryons and mesons using incident neutrons. We show evidence for the charm-strange baryon, ..xi../sub c//sup +/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the ..sigma../sub c//sup + +/ and ..sigma../sub c//sup 0/, and present measurements of three mass differences, ..sigma../sub c//sup + +/ - ..sigma../sub c//sup 0/, ..sigma../sub c//sup 0/ - ..lambda../sub c//sup +/, and ..sigma../sub c//sup + +/ - ..lambda../sub c//sup +/. Preliminary results on the ratio of two decay modes of the D/sup 0/ are shown. D/sup 0/ ..-->.. K/sup +/K/sup -/ and D/sup 0/ ..-->.. K/sub 0/ anti K/sub 0/. The latter mode has not been previously observed. 8 refs., 10 figs.

The giant planets - Jupiter, Saturn, Uranus, and Neptune - differ markedly from the inner, or terrestrial, planets. Observations of their average density, gravitational moments, and atmospheric composition have enabled astrophysicists to draw some conclusions as to their structure, but efforts have been hampered by a lack of accurate data on the chemical, physical, and thermodynamic properties of constituent materials at the extremely high temperatures and pressures characteristic of planetary interiors. Shock-wave experiments conducted recently at LLNL have provided more accurate equations of state and electrical conductivities for many of these materials, and these have led to improved structural models of the giant planets.

This paper discusses the basis of a design for real time special nuclear material (SNM) loss detectors. The design utilizes process measurements and signal processing techniques to produce a timely estimate of material loss. A state estimator is employed as the primary signal processing algorithm. Material loss is indicated by changes in the states or process innovations (residuals). The design philosophy is discussed in the context of these changes.

This paper is concerned with intense electron beams, typically of the order of a few kA in current and up to tens of MeV in beam energy. A beam of this kind can be produced from induction machines, examples of which are the ERA (4 MeV, 1 kA) at Lawrence Berkeley Laboratory and the ASTRON (5 MeV, 500A), ETA (5 MeV, 10 kA), and ATA (50 MeV, 10 kA) at Lawrence Livermore National Laboratory (LLNL). The emphasis of the paper is on the characteristics of these beams and some applications. 13 refs., 2 figs. (LSP)

Anomalous low-J-value Stokes and anti-Stokes lines in stimulated rotational Raman scattering are observed with large Fresnel number, linearly polarized beams. Forced light scattering at the rotational intermodulation frequency is also observed. Dynamics of the Stokes-anti-Stokes coupling will be discussed. 5 refs., 2 figs.

We have studied actinide burn-up in ICF reactor pellets; i.e., 14 MeV neutron fission of the very long-lived actinides that pose storage problems. A major advantage of pellet fuel region burn-up is safety: only milligrams of highly toxic and active material need to be present in the fusion chamber, whereas blanket burn-up requires the continued presence of tons of actinides in a small volume. The actinide data tables required for Monte Carlo calculations of the burn-up of /sup 241/Am and /sup 243/Am are discussed in connection with a study of the sensitivity to cross section uncertainties. More accurate and complete cross sections are required for realistic quantitative calculations.

Four accelerator parameters were found to control the condition of the electron beam entering the Intergrated Fast Reactor (IFR). These parameters were the matching of the electron beam to the ion channel, the laser timing, the benzene pressure at the entrance to the IFR, and the timing of the accelerator gaps. Manipulation of these parameters make possible the control of the total current, the emittance, the pulse length, the mixture of laser induced current and cathode current, the radial growth in time, the final size of the beam, and the energy variation through the pulse. 1 fig.

The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Japan, the European Community, the Union of the Soviet Union, and the United States. This paper examines the effects of a quench within the toroidal field (TF) coils based on current ITER design. It is a preliminary, rough analysis. Its intent is to assist ITER designers while more accurate computer codes are being developed and to provide a check against these more rigorous solutions. Rigorous solutions to the quench problem are very complex involving three- dimensional heat transfer, extreme changes in heat capacities and copper resistivity, and varying flow dynamics within the conductors. This analysis addresses all these factors in an approximate way. The result is much less accurate than a rigorous analysis. Results here could be in error as much as 30 to 40 percent. However, it is believed that this paper can still be very useful to the coil designer. Coil pressures and temperatures vs time into a quench are presented. Rate of helium vent, energy deposition in the coil, and depletion of magnetic stored energy are also presented. Peak pressures are high (about 43 MPa). This is due to the very …

The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Japan, the European Community, the Soviet Union, and the United States. ITER will be a large machine requiring up to 100 kW of refrigeration at 4.5 K to cool its superconducting magnets. Unlike earlier fusion experiments, the ITER cryogenic system must handle pulse loads constituting a large percentage of the total load. These come from neutron heating during a fusion burn and from ac losses during ramping of current in the PF (poloidal field) coils. This paper presents a conceptual design for a cryogenic system that meets ITER requirements. It describes a system with the following features: Only time-proven components are used. The system obtains a high efficiency without use of cold pumps or other developmental components. High reliability is achieved by paralleling compressors and expanders and by using adequate isolation valving. The problem of load fluctuations is solved by a simple load-leveling device. The cryogenic system can be housed in a separate building located at a considerable distance from the ITER core, if desired. The paper also summarizes physical plant size, cost estimates, and means of handling vented helium during magnet quench. 4 …

The double-cone-shaped Cascade reaction chamber rotates at 50 rpm to keep a blanket of ceramic granules in place against the wall as they slide from the poles to the exit slots at the equator. The 1 m-thick blanket consists of layers of carbon, beryllium oxide, and lithium aluminate granules about 1 mm in diameter. The x rays and debris are stopped in the carbon granules; the neutrons are multiplied and moderated in the BeO and breed tritium in the LiAlO/sub 2/. The chamber wall is made up of SiO tiles held in compression by a network of composite SiC/Al tendons. Cascade operates at a 5 Hz pulse rate with 300 MJ in each pulse. The temperature in the blanket reaches 1600 K on the inner surface and 1350 K at the outer edge. The granules are automatically thrown into three separate vacuum heat exchangers where they give up their energy to high pressure helium. The helium is used in a Brayton cycle to obtain a thermal-to-electric conversion efficiency of 55%. Studies have been done on neutron activation, debris recovery, vaporization and recondensation of blanket material, tritium control and recovery, fire safety, and cost. These studies indicate that Cascade appears to …

The materials accounting system at Los Alamos has evolved from an ''80-column'' card system to a very sophisticated near-real-time computerized nuclear material accountability and safeguards system (MASS). The present hardware was designed and acquired in the late 70's and is scheduled for a major upgrade in fiscal year 1986. The history of the system from 1950 through the DYMAC of the late 70's up to the present will be discussed. The philosophy of the system along with the details of the system will be covered. This system has addressed the integrated problems of management, control, and accounting of nuclear material successfully. 8 refs., 3 figs., 1 tab.