The primary physics objective of the 4{pi} TPC magnetic spectrometer proposal is to search for the Quark-Gluon Plasma. In previous workshops we have discussed what the possible hadronic signatures of such a state of matter would be. Succinctly, the QGP is a direct prediction of non-perturbative QCD. Therefore the question of the existence of this new state of matter bears directly on the validity of non-perturbative QCD. However, since non-perturbative QCD has never been established, it is apparent that what may await us is a host of new phenomena that will go beyond the standard model.

Los Alamos National Laboratory has completed the engineering design and development for the high power electrical switching networks for the ZTH experiment. ZTH is Reversed Field Pinch (RFP) plasma experiment with a 4 MA plasma current capability. Power to the ohmic heating (OH), equilibrium field (EF), and toroidal field (TF) coils will be provided from a 1.43 GVA turbo-alternator, which has over 600 MJ of extractable energy. The DC interrupting switch will handle 2.4 GVA, 150 MJ during initial machine operations. An additional 150 to 200 MJ are required for flat-topping the plasma current. A new ultra-high power switch, designed and tested at Los Alamos, will be used to reconfigure the power supply connections so that the supplies can be switched from parallel to series operation. In this manner, the same supplies can be used to charge and then flat-top the OH coils. The inexpensive cost of these switches results in significant economy of power supplies and systems. Detailed engineering information will be presented for the family of 25 kA and 50 kA, 50kV fast isolation and transfer switches, including testing of special water-cooled units capable of 50,000 amperes continuous duty. Similarly, detailed engineering data will be provided for the …

The discovery in 1982, by the EMC group, that the structure function F{sub 2}(x) per nucleon is different in iron than deuterium was the first evidence that the structure of the nucleon might be altered in nuclei. Much more extensive and precise and data have been taken since the original discovery. This body of data is now quite consistent and many of the features of the original EMC effect'' remain intact. There have been a variety of theoretical explanations of the data, but none are totally compelling. The deep-inelastic-scattering (DIS) data for the ratio of F{sub 2}{sup Fe}(x) in iron to F{sub 2}{sup D}(x) in deuterium are given for the region 0.03 {le} {times} {le} {approximately} 1.0.

Severe accident studies for the Savannah River production reactors indicate that if coherent fuel melting and relocation occur in the absence of target melting, in-vessel recriticality may be achieved. In this paper, fuel-melt/target interaction potential is assessed, where fission gas-induced fuel foaming and melt attach on target material are evaluated and compared with available data. Models are developed to characterize foams for irradiated Al-based fuel. Predictions indicate transient foaming (the extent of which is governed by fission gas inventory), heating transient, and bubble coalescence behavior. The model also indicates that metallic foams are basically unstable and will collapse, which largely depends on film tenacity and melt viscosity. For high-burnup fuel, foams lasting tens of seconds are predicted, allowing molten fuel to contact and cause melt ablation of concentric targets. For low-burnup fuel, contact can not be assured, thus recriticality may be of concern at reactor startup. 8 refs., 4 figs., 4 tabs.

Pressurized-water reactors have reactor physics and fuel management characteristics which are very amenable to simplified analysis. Given models which account for the dominant features of core and fuel performance, it is possible to rapidly perform relatively accurate scoping studies of many years of reactor operation in just a few hours on a modern (386-class) microcomputer. Models are described for burnup-dependent cross-section generation, for burnup of fuel under irradiation, and for computation of radial power distributions in hexagonal geometry assuming hexagonal fuel assemblies. Comparisons with more elaborate methods are given in order to validate the models, and to quantify the accuracy of the results. 16 refs., 5 figs., 5 tabs.

A series of abstracts is given on the subjects of theory for multiply charged ions and low- and high-energy collisions involving multiply charged ions. 23 refs.

A series of abstracts is given on the subjects of theory for multiply charged ions and low- and high-energy collisions involving multiply charged ions. 23 refs.

Acceleration of the convergence of approximate operator iteration schemes is discussed. Algorithms based on both residual minimization and use of conjugate vector spaces are presented. It is shown that both give dramatic improvement, at very low computational cost, in the iterative solution of radiative transfer problems in the presence of scattering. 13 refs., 7 figs.

Accelerator-based neutron sources for R D of materials in nuclear energy systems, including fusion reactors, can provide sufficient neutron flux, flux-volume, fluence and other attractive features for many aspects of materials research. The neutron spectrum produced from the D-Li reaction has been judged useful for many basic materials research problems, and to be a satisfactory approximation to that of the fusion process. The technology of high-intensity linear accelerators can readily be applied to provide the deuteron beam for the neutron source. Earlier applications included the Los Alamos Meson Physics Facility and the Fusion Materials Irradiation Test facility prototype. The key features of today's advanced accelerator technology are presented to illustrate the present state-of-the-art in terms of improved understanding of basic physical principles and engineering technique, and to show how these advances can be applied to present demands in a timely manner. These features include how to produce an intense beam current with the high quality required to minimize beam losses along the accelerator and transport system that could cause maintenance difficulties, by controlling the beam emittance through proper choice of the operating frequency, balancing of the forces acting on the beam, and realization in practical hardware. A most interesting aspect …

As the dimensions of accelerating structures become smaller and beam intensities higher, the non-axisymmetric wake fields driven by the beam become quite large even with slight misalignments of the beam from the geometrical axis. These deflection modes then cause bunch-to-bunch beam breakup and intra-bunch head-tail instabilities. An rf show-wave structure that has very low Q for the deflection modes while maintaining a high Q for the accelerating modes would then be desirable since the unwanted modes can be selectively damped. Such a device utilizing dielectric-lined waveguide is shown in this paper where the uniform outer conductor is replaced by axial, closely spaced, insulated wires which allow only axial wall currents to flow at that boundary. This dielectric-based configuration is of specific interest to the Cerenkov wake-field accelerator program under development at Argonne. A configuration consistent with traditional iris-loaded waveguide is given in this paper where the outer conductor is segmented to allow only axial currents and the irises are segmented to allow only radial currents. Severe enough damping in either configuration to eliminate the head-tail instability could be difficult to obtain depending on the bunch length considered, but strong enough damping to combat bunch-to-bunch beam breakup using these schemes appears …

Particle accelerators are important tools for materials research and production. Advances in high-intensity linear accelerator technology make it possible to consider enhanced neutron sources for fusion material studies or as a source of spallation neutrons. Energy variability, uniformity of target dose distribution, target bombardment from multiple directions, time-scheduled dose patterns, and other features can be provided, opening new experimental opportunities. New designs have also been used to ensure hands-on maintenance on the accelerator in these factory-type facilities. Designs suitable for proposals such as the Japanese Energy-Selective Intense Neutron Source, and the international Fusion Materials Irradiation Facility are discussed.

The use of AMS to measure nuclear quantities is reviewed. Particular emphasis is put on the discussion of half-life measurements and searches for hypothetical particles. 30 refs., 6 figs.

A review was presented of operating, planned and high energy accelerators under construction in the US. It was pointed out that the program is broad based, addressing a variety of frontiers and encompassing many of most fruitful projectiles, intensities, and energy ranges. The US program is also geographically diversified across the country in major research centers. The physics productivity over the past years has been excellent with a emphasis on the importance of sustaining the base program at least until the SSC is operating and possibly beyond. 9 figs.

Most previous Probabilistic Risk Assessments have excluded consideration of accidents initiated in low power and shutdown modes of operation. A study of the risk associated with operation in low power and shutdown is being performed at Sandia National Laboratories for a US Boiling Water Reactor (BWR). This paper describes the proposed methodology for the analysis of the risk associated with the operation of a BWR during low power and shutdown modes and presents preliminary information resulting from the application of the methodology. 2 refs., 2 tabs.

Accurate calculations of kerma (Kinetic Energy Released in MAterials) factors and displacement cross sections are fundamental to studies of neutron heating and neutron radiation damage. Damage and heating studies are important elements in both fission and fusion reactor design. For fusion reactor studies, heating in the blanket helps determine the efficiency, and heating studies in the superconducting magnet regions determine properties of the blanket and shield, thereby affecting the economics of the reactor. Radiation damage is important for reactor core lifetime studies and is related directly to the economy and safety of both fusion and fission reactors. Calculation of kerma factors and displacement cross sections require nuclear data for neutron-induced reactions. These data are normally obtained from evaluated nuclear data libraries, such as ENDF/B (US), JENDL (Japan), JEF/EFF (Europe) and BROND (USSR). Unfortunately, most of these evaluated libraries do not contain sufficient information for a direct calculation of these quantities, and various approximations must be employed. The accuracy of the kerma factors and displacement cross sections, and thus the heating and damage functions, are directly related to the available information from the data libraries. In this paper we describe improvements incorporated in the latest version of the US library, ENDF/B-VI, …

In this paper, we propose a new algorithm for computing a singular value decomposition of a product of three matrices. We show that our algorithm is numerically desirable in that all relevant residual elements will be numerically small. 12 refs., 1 tab.

The most compact way of describing general texture information is by way of a file of weighted discrete grains. When the textures are strong, this results in a great saving of necessary parameters. The most efficient way is a random file from which grains with low weights get discarded. This method is routine and independent of any preknowledge of the texture or even the symmetries. Typically, the order of 100 grains are sufficient for strong textures or fiber textures. Furthermore, these grains files are directly in the kind of format that is useful for computer simulation of current anisotropic properties or future texture development. For textures that are not very sharp, but nevertheless are not properly represented as random (which would imply isotropic properties), one may also use weighted-grains files, but here the number of grains needed may be large for an accurate representation. We have found that on the order of 1000 weighted grains are sufficient for most cases. When the symmetries are known, grains that are regularly (rather than randomly) arranged in orientation space are useful -- again better when they are weighted.

The ACEEE Summer Study is a biennial conference that aims to bring together the foremost researchers, practitioners and policy makers involved in research on energy efficiency in buildings. The 1990 Summer Study had the objective to facilitate the exchange of research and implementation results and encourage the advancement of knowledge in the field of energy efficiency in buildings. The research papers presented at the conference published and distributed. Two hundred seventy two papers were presented. These individual papers, published in ten volumes, have been processed separately for the Energy Data Base.

This report contains the abstracts for 55 presentations given at the fourteenth annual Actinide Separations Conference. (JDL)

Photoacoustic spectroscopy using pulsed laser excitation is being developed by a number of research groups as one of the most promising methods or studying speciation of actinides in solution at environmentally relevant concentrations. We present details of a number of hardware and software techniques we have implemented to improve the sensitivity of the method. Our approach is based on more extensive waveform analysis. While most signal processing techniques extract the analytical signal from only a small portion of the acoustic waveform produced in the detector by an absorption event, we describe two methods that use more of the waveform. Other methods of minimizing noise sources using both hardware and software are also described. 9 refs., 5 figs., 1 tab.

Extensive theoretical treatment is given to damping as the process of energy dissipation during mechanical vibration. The challenge in the classroom is to adequately convey this concept and extend it by teaching students practical applications in engineering analysis and design. Students are motivated by real-world problems; applying these types of problems with strong instructional classroom content significantly enhances the learning environment. This paper proposes the adaptation of an actual research project to a simple, yet innovative, mechanical vibrations laboratory. The adapted project involves an ongoing effort at the Los Alamos National Laboratory to investigate damping factors of various alloys used in military tank munitions. The kinetic-energy penetrators used in these tank rounds are cylindrical in shape and are a major class of weapons designed to defeat heavy armor. Unwanted transverse oscillations of these penetrators degrade the accuracy of the rounds and may lead to glancing blows off the target. 5 refs., 3 figs.

Modifications to SW-846 sample preparation methodology permit the organic analysis of radioactive mixed waste with minimum personal radiation exposure and equipment contamination. This paper describes modifications to SW-846 methods 5030 and 3510-3550 for sample preparation in radiation-zoned facilities (hood, glove box, and hot cell) and GC-MS analysis of the decontaminated organic extracts in a conventional laboratory for volatile and semivolatile organics by methods 8240 and 8270 (respectively). Results will be presented from the analysis of nearly 70 nuclear waste storage tank liquids and 17 sludges. Regulatory organics do not account for the organic matter suggested to be present by total organic carbon measurements. 7 refs., 5 tabs.

To understand the kinetic processes that determine energy confinement and impurity production in magnetic confinement experiments, we are developing methods to model kinetic effects on magnetohydrodynamic time scales in realistic geometries. We are using implicit methods and adaptive grids to achieve this goal. 9 refs., 2 figs.

In mammals, variability in the genetic sensitivity of different germ-cell stages to mutagens could be the result of how much chemical reaches the different stages, what molecular targets may be affected in the different stages and whether or not repair of lesions occurs. In the mouse, several mutagens have been found that cause their greatest genetic damage in late-spermatid and early-spermatozoa stages and that also bind very strongly to the protamine in these stages. Chemicals which are less genetically damaging to these stages have been found to have much less affinity for protamine. Furthermore, the level of chemical binding to DNA in late-spermatid and early-spermatozoa stages has not been correlated with the level of induced genetic damage, although DNA breakage in these sensitive stages has been shown to increase. This DNA damage is believed to indirectly result from chemical binding to sulfhydryl groups in protamine which prevents normal chromatin condensation within the sperm nucleus. 16 refs., 5 figs.