The DIvertor Material Evaluation System (DIMES) at DIII-D is a collaborative program between General Atomics, Sandia National Laboratories (SNL), and Argonne National Laboratory (ANL). This program was initiated in response to the need for understanding the interaction between the plasma and divertor surface materials in tokamaks. Material erosion, tritium retention, disruption effects and material transport are very important topics for the design of ITER. The first phase of the DIMES study is integral material exposure measurements. The second phase of the study is the installation of the DIMES sample changer mechanism. The mechanical design goal for the second phase is to allow the insertion of instrumented samples into the bottom divertor plat region of DIII-D without venting the tokamak. Different material samples can then be exchanged overnight after as few as one plasma shot of exposure. This paper presents the results of the integral experiments, the design of the DIMES sample changer mechanism and the planning of material evaluation experiments at DIII-D using the DIMES mechanism.

Massive stars that end their stable evolution as their iron cores collapse to a neutron star or black hole long been considered good candidates for producing Type II supernovae. For many years the outward propagation of the shock wave produced by the bounce of these iron cores has been studied as a possible mechanism for the explosion. For the most part, the results of these studies have not been particularly encouraging, except, perhaps, in the case of very low mass iron cores or very soft nuclear equations of state. The shock stalls, overwhelmed by photodisintegration and neutrino losses, and the star does not explode. More recently, slow late time heating of the envelope of the incipient neutron star has been found to be capable of rejuvenating the stalled shock and producing an explosion after all. The present paper discusses this late time heating and presents results from numerical calculations of the evolution, core collapse, and subsequent explosion of a number of recent stellar models. For the first time they all, except perhaps the most massive, explode with reasonable choices of input physics. 39 refs., 17 figs., 1 tab.

The impacts of the SPS on astronomy were concluded to be: increased sky brightness, reducing the effective aperture of terrestrial telescopes; microwave leakage radiation causing erroneous radioastronomical signals; direct overload of radioastronomical receivers at centimeter wavelengths; and unintentional radio emissions associated with massive amounts of microwave power or with the presence of large, warm structures in orbit causing the satellites to appear as individual stationary radio sources; finally, the fixed location of the geostationary satellite orbits would result in fixed regions of the sky being unusable for observations. (GHT)

Microstructurally-induced changes in the local stress state (triaxial constraint) and their effect on fracture-toughness behavior are examined at ambient and cryogenic temperatures in an Al-Li-Cu-Zr alloy, processed in the form of 12.7 mm-thick naturally laminated'' plate containing aligned-weak interfaces and 1.6 mm-thin unlaminated sheet. It is shown that marked improvements in long-transverse (L-T) toughness can be achieved in the plate material at cryogenic temperatures by promoting through-thickness delamination along these interfaces, which relaxes local constraint and promotes a fracture-mode transition from global plane strain to local plane stress. Conversely, in thin sheet material, the absence of such interface delamination leads to a reduction in toughness with decrease in temperature, consistent with the greater degree of crack-tip constraint. 17 refs., 4 figs., 1 tab.

The pressurized fluidized-bed combustion technology exchange workshop was held June 5 and 6, 1979, at The Meadowlands Hilton Hotel, Secaucus, New Jersey. Eleven papers have been entered individually into EDB and ERA. The papers include reviews of the US DOE and EPRI programs in this area and papers by Swedish, West German, British and American organizations. The British papers concern the joint program of the USA, UK and FRG at Leatherhead. The key factor in several papers is the use of fluidized bed combustors, gas turbines, and steam turbines in combined-cycle power plants. One paper examines several combined-cycle alternatives. (LTN)

We discuss the spectrum of physics questions related to strangeness which could be addressed with a 15--30 GeV proton storage ring. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hyper-fragments in p-nucleus collisions, and hyperon spin observables in inclusive production.

Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

Three results are presented: (1) The semi-leptonic branching ratio of the ..lambda../sub c/ has been measured at SPEAR to be B(..lambda../sub c//sup +/ ..-->.. e/sup +/X) = (4.5 +- 1.7)%. (2) Properties of tau-pair production have been measured at PEP at square root S = 29 GeV: sigma/sup tau tau//sigma/sup QED/ = 0.97 +- 0.05 +- 0.06; the forward-backward asymmetry is A/sub tau tau/ = (-3.5 +- 5.0)%; inclusive branching ratios are B(tau ..-->.. 1 Prong) = (86 +- 4)%, B(tau ..-->.. 3 Prongs) = (14 +- 4)%, B(tau ..-->.. 5 Prongs) < 0.6% (95% C.L.). (3) A search has been performed for the pair production of charged, point-like, spin 0 particles. The existence of such particles can be ruled out at a 90% confidence level for 3 approx. < M approx. < 10 GeV/c/sup 2/ and branching ratio into hadrons approx. < 90%.

The experimentally observed Fermi surface properties in URh/sub 3/, UIr/sub 3/, UGe/sub 3/, CeSn/sub 3/, CeB/sub 6/, U/sub 3/As/sub 4/, U/sub 3/P/sub 4/, and CeSb are reviewed. For the compounds with no magnetic order, band structure models of the Fermi surface geometry are confirmed and f-ligand hybridization is found to be dominant. For CeB/sub 6/, U/sub 3/As/sub 4/, and U/sub 3/P/sub 4/ the experiments show that both local moments and f hybridization are important. In CeSb new data can be explained by a purely local model with no f-hybridization.

The solar-weighted hemispheric reflectance of unweathered silvered acrylic mirrors exceeds 92%, and specular reflectance into a 4- milliradian, full-cone acceptance angle is greater than 90%. Comparison of outdoor and accelerated tests suggests that the protected silver can resist corrosion for the five-year life that is the current goal. An installation of parabolic troughs has been cleaned monthly for two years, and reflectance is regularly returned to within a few percent of the initial reflectance values. In the presence of moisture, the silver/acrylic bond can delaminate to form a maze of tunnels and destroy specular reflectance. Proper edge preparation and protection delay the initiation of tunnels. 6 refs.

There are currently six DOE-funded solar industrial process heat (IPH) field tests which have been operational for one year or longer. These are all low temperature first generation projects which supply heat at temperatures below 100/sup 0/C - three hot water and three hot air. During the 1979 calendar year, personnel from the Solar Energy Research Institute (SERI) visited all of these sites; the performance and cost results obtained for each project and the operational problems encountered at each site are discussed.

Solar thermal technology, coupled with aggressive conservation measures, offers the prospect of greatly reducing the dependence of industry on oil and natural gas. The near-term market for solar technology is largely in industrial processes operating at temperatures below 288/sup 0/C (550/sup 0/F). Such process heat can be supplied by the relatively unsophisticated solar equipment available today. The number and diversity of industrial plants using process heat at this temperature allows favorable matches between solar technologies and industrial processes. The problems involved with the installation and maintenance of conservation and solar equipment are similar. Both compete for scarce investment capital, and each complicates industrial operations and increases maintenance requirements. Technological innovations requiring new types of equipment and reducing the temperature requirements of industrial processes favor the introduction of solar hardware. The industrial case studies program at the Solar Energy Research Institute has examined technical, economic, and other problems facing the near-term application of solar thermal technology to provide industrial process heat. The plant engineer is in the front line of any measure to reduce energy consumption or to supplement existing fuel supplies. The conditions most favorable to the integration of solar technology are presented and illustrated with examples from actual industrial …

For radiation protection purposes of k-fluorescence x-rays are useful for determining the energy response of instruments and dosimeters because they are nearly monoenergetic. the International Organization for Standardization (ISO) has specified the x-ray energies and radiator and filter materials for the production of such x-rays. There are two techniques useful for producing x-rays at approximately 17 and 59 keV; these techniques produce a situation that approximates the x-ray and gamma ray emissions of plutonium and americium isotopes. The Department of Energy Laboratory Accreditation Program (DOELAP) performance-testing standard for personnel dosimeters incorporates these k-fluorescence techniques. The Radiation Calibrations Facility at the Pacific Northwest Laboratory (PNL) has produced k-fluorescence x-rays for many years. Over the years, we have worked at improving this type of radiation for our performance-testing programs. This report describes the present geometry for the generation of k-fluorescence x-rays, a geometry proven more efficient in our facility. The exposure rate has increased and the beam uniformity has improved. Details of the geometry will be discussed.

A portable, remote-controlled mass spectrometer was required at the Nevada Test Site to analyze prompt post-event gas from the nuclear cavity in support of the underground testing program. A Balzers QMG-511 quadrupole was chosen for its ability to be interfaced to a DEC LSI-11 computer and to withstand the ground movement caused by this field environment. The inlet system valves, the pumps, the pressure and temperature transducers, and the quadrupole mass spectrometer are controlled by a read-only-memory-based DEC LSI-11/2 with a high-speed microwave link to the control point which is typically 30 miles away. The computer at the control point is a DEC LSI-11/23 running the RSX-11 operating system. The instrument was automated as much as possible because the system is run by inexperienced operators at times. The mass spectrometer has been used on an initial field event with excellent performance. The gas analysis system is described, including automation by a novel computer control method which reduces operator errors and allows dynamic access to the system parameters.

Several Monte Carlo techniques are compared in the transport of neutrons of different source energies through two different deep-penetration problems each with two parts. The first problem involves transmission through a 200-cm concrete slab. The second problem is a 90/sup 0/ bent pipe jacketed by concrete. In one case the pipe is void, and in the other it is filled with liquid sodium. Calculations are made with two different Los Alamos Monte Carlo codes: the continuous-energy code MCNP and the multigroup code MCMG.

The transport critical current density (Jc) for high-{Tc} thin films, bicrystals, and bulk ceramics is shown to be determined by magnetic field penetration into the grain boundaries. The gross grain orientations may not in all cases be an important factor in determining this penetration. The parameter ({lambda}{sub G}/{lambda}{sub J}){sup 2} can characterize the strength of the grain boundary coupling, which depends mainly on the crystal coherence and connectivity at the boundary area.

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The US Department of Energy is studying the Alligator Rivers Natural Analogue Project site at Koongarra, Northern Territory, Australia to investigate and simulate radionuclide migration in fractured rocks. Discrete fracture simulations were conducted within a cubic volume (180-m edge length) of fractured Cahill Formation schist oriented with one major axis parallel to the trend of the Koongarra Fault. Five hundred fractures are simulated within this domain. The fractures have a mean orientation parallel to the idealized plane of the Koongarra Fault dipping 55{degrees} SE. Simple flow modeling of this fracture network was conducted by assigning constant head boundaries to upgradient and downgradient vertical faces of the cube, which trend parallel to the fault. No-flow boundaries were assigned to all other faces. The fracture network allows hydraulic communication across the block, in spite of relatively low fracture density across the block.

Energy supply disruptions do not suddenly arise in a full-blown fashion. Lags in the energy system provide a time horizon which allows for the prediction of a possible supply problem. A simple model is described which can be used to provide a set of indicators for the possible onset of an energy emergency. The methodology was tested on the gasoline shortage of 1979, and the results are presented.

The controversy over the relative advantages of standing-wave and traveling-wave linear accelerators is now in its fourth decade. It has been fed by a considerable body of misinformation. The author hopes in this paper to shed some light on the subject, and expose some of the falsehoods. The discussion is directed toward the question of which structure to use for short pulse high field electron accelerators since it is almost universally accepted that standing-wave structures are appropriate for CW and long pulse accelerators. Three arguments against standing-wave accelerators are discussed and shown to be invalid.

This is an exciting time for water resources planners and environmental scientists in the State and Federal Agencies in California. The growing environmental awareness of the public has raised their interest in the manner by which water is managed and allocated. Current and future impending water shortages are challenging engineers and planners to make sound policy and system operations decisions to maximize the utility of scarce water resources while ensuring that the environment within which we live is adequately protected to the satisfaction of an informed public. New and innovative decision support systems are needed to meet these challenges that are flexible, comprehensible and accurate and which allow the public a more visible role in the planning process. These changes may help to bring the agricultural and environmental communities closer together in finding solutions to water resources problems and wrest policy making for water resources management out of the hands of lawyers and the courts and restore it to those whose livelihoods are affected by the intentions of these policies. 4 refs.

Low-temperature measurements of muonium parameters in various germanium crystals have been performed. We have measured crystals with different levels of neutral impurities, with and without dislocations, and with different annealing histories. The most striking result is the apparent trapping of Mu by silicon impurities in germanium.

Accelerator-based, pulsed spallation neutron sources have been performing neutron scattering research for about fifteen years. During this time beam intensities have increased by a factor of 100 and more than 50 spectrometers are now operating on four major sources worldwide. The pulsed sources have proven to be highly effective and complementary to reactor-based sources in that there are important scientific areas for which each type of source has unique capabilities. We describe a proposal for a new pulsed neutron facility based on a Fixed Field Alternating Gradient synchrotron. The specifications for this new machine, which are now only being formulated, are for an accelerator that will produce (100 {divided by} 200) {mu}A of time-averaged proton current at (500 {divided by} 1000) MeV, in short pulses at 30 Hz. Appropriate target and moderator systems and an array of scattering instruments will be provided to make the facility a full-blown research installation. The neutron source, named the Pulsed Neutron Research Facility (PNRF), will be as powerful as any pulsed source now operating in the world and will also act as a test bed for the Fixed Field Alternating Gradient Synchrotron concept as a basis for more powerful sources in the future. The …

The design geometry of the SSC dipole cryostat includes active thermal radiation shields operating at 80K and 20K respectively. Extensive measurements conducted in a Heat Leak Test Facility (HLTF) have been used to evaluate the thermal performance of candidate multilayer insulation (MLI) systems for the 80K thermal shield, with the present system design based upon those measurement results. With the 80K MLI geometry established, efforts have focused on measuring the performance of MLI systems near 20K. A redesign of the HLTF has produced a measurement facility capable of conducting measurements with the warm boundary fixed at 80K and the cold boundary variable from 10K to 50K. Removing the 80K shield permits measurements with a warm boundary at 300K. The 80K boundary consists of a copper shield thermally anchored to a liquid nitrogen reservoir. The cold boundary consists of a copper anchor plate whose temperature is varied through boil-off gas from a 500 liter helium supply dewar. A transfer line heat exchanger supplies the boil-off gas to the anchor plate at a constant and controlled rate. The gas, which serves as cooling gas, is routed through a copper cooling tube soldered into the anchor plate. Varying the cooling gas flow rate …