Computed and experimental interactions between eddy structure and dispersed particles in developing free shear layers (open access)

Computed and experimental interactions between eddy structure and dispersed particles in developing free shear layers

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.
Date: May 20, 1982
Creator: Buckingham, A. C.; Siekhaus, W. J.; Keller, J. O.; Ellzey, J.; Hubbard, G. & Daily, J. W.
Object Type: Article
System: The UNT Digital Library
Automatic voltage-imbalance detector (open access)

Automatic voltage-imbalance detector

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.
Date: May 20, 1981
Creator: Bobbett, R. E.; McCormick, J. B. & Kerwin, W. J.
Object Type: Patent
System: The UNT Digital Library
Fusion product deposition and energy balance (open access)

Fusion product deposition and energy balance

Extensive Monte-Carlo calculations were performed of alpha-particle deposition in the Hill's Vortex configuration, as reported in D.E. Driemeyer's Ph.D. Thesis (University of Illinois, 1980). This has generally been done including a cold plasma density, n/sub c/, on the open field lines, with n/sub C//T/sub C//sup 3/2/ approx. = n/sub H//T/sub H//sup 3/2/ - i.e. with the slowing down ratio tau/sub H//tau/sub C/ lying between .1 and 10. Since many of the alpha particles spend a significant amount of their time on the open field lines, values of tau/sub H//tau/sub C/ greater than unity lead to significant removal of alpha-particle ash from the closed-field region. Surprisingly, one is able to perform this ash removal and still retain enough energy to raise the reactor Q significantly (or even ignite it).
Date: May 20, 1980
Creator: Condit, W.C. & Driemeyer, D.E.
Object Type: Report
System: The UNT Digital Library
Radiation interactions for tomography. Revision 1 (open access)

Radiation interactions for tomography. Revision 1

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.
Date: May 20, 1985
Creator: Zolnay, A.S.
Object Type: Article
System: The UNT Digital Library
Tracking federal land management: Report No. 3 on federal land management actions impacting geothermal commecialization at selected target prospects in the five Pacific Rim states (open access)

Tracking federal land management: Report No. 3 on federal land management actions impacting geothermal commecialization at selected target prospects in the five Pacific Rim states

Generic land management actions affecting geothermal commerializtion in Pacific River states are reviewed. Specific federal land management actions affecting geothermal prospects in California and the Pacific Northwest are described. (MHR)
Date: May 20, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Reduction of the beam breakup mode Q values in the ETA/ATA Accelerating Cells (open access)

Reduction of the beam breakup mode Q values in the ETA/ATA Accelerating Cells

Earlier Microwave Measurements of the ETA Accelerating Cells has uncovered eleven resonances in the frequency range of 0 > 850 MHz. The Q values of these modes ranged from 14 to 70. A three phase program directed at substantially reducing these Q values is reported. In particular the dampening methods described below resulted in a decrease of Q value from 40 to 5 for the beam breakup mode (TM/sub 110/) with a corresponding reduction for most of the other cavity modes.
Date: May 20, 1980
Creator: Birx, D.L.
Object Type: Report
System: The UNT Digital Library
Fundamentals and techniques of nonimaging optics for solar energy concentration. Final report (open access)

Fundamentals and techniques of nonimaging optics for solar energy concentration. Final report

Nonimaging optics is a new discipline with techniques, formalism and objectives quite distinct from the traditional methods of focusing optics. These new systems achieve or closely approach the maximum concentration permitted by the Second Law of Thermodynamics for a given angular acceptance and are often called ideal. Application of these new principles to solar energy over the past seven years has led to the invention of a new class of solar concentrators, the most well known version of which is the Compound Parabolic Concentrator or CPC. A new formalism for analyzing nonimaging systems in terms of a quantity called the geometrical vector flux has been developed. This has led not only to a better understanding of the properties of ideal concentrators but to the discovery of several new concentrator designs. One of these new designs referred to as the trumpet concentrator has several advantageous features when used as a secondary concentrator for a point focusing dish concentrator. A new concentrator solution for absorbers which must be separated from the reflector by a gap has been invented. The properties of a variety of new and previously known nonimaging optical configurations have been investigated: for example, Compound Elliptical Concentrators (CEC's) as secondary …
Date: May 20, 1980
Creator: Winston, R.
Object Type: Report
System: The UNT Digital Library
Cascade ICF power reactor (open access)

Cascade ICF power reactor

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 …
Date: May 20, 1986
Creator: Hogan, W.J. & Pitts, J.H.
Object Type: Article
System: The UNT Digital Library
Scalar potential for charge distributions with ellipsoidal symmetry (open access)

Scalar potential for charge distributions with ellipsoidal symmetry

Calculation of the electrostatic scalar potential in ellipsoidal coordinates is outlined. The ellipsoidal coordinate system is described, and the Laplace equation is discussed for this system. Special charge distributions having ellipsoidal symmetry, and therefore most easily treated in ellipsoidal coordinates, are assumed and their scalar potentials calculated, including the ellipsoidal shell, two-dimensional and three-dimensional Gaussian charge distribution, and two-dimensional uniform distribution. 2 refs. (LEW)
Date: May 20, 1986
Creator: Gluckstern, R.L.
Object Type: Report
System: The UNT Digital Library
Economic studies for heavy-ion-fusion electric power plants (open access)

Economic studies for heavy-ion-fusion electric power plants

We have conducted parametric economic studies for heavy-ion-fusion electric power plants. We examined the effects on the cost of electricity of several design parameters: cost and cost scaling for the reactor, driver, and target factory; maximum achievable chamber pulse rate; target gain; electric conversion efficiency; and net electric power. Using the most recent estimates for the heavy-ion-driver cost along with the Cascade reactor cost and efficiency, we found that a 1.5 to 3 GWe heavy-ion-fusion power plant, with a pulse rate of 5 to 10 Hz, can be competitive with nuclear and coal power plants.
Date: May 20, 1986
Creator: Meier, W. R.; Hogan, W. J. & Bangerter, R. O.
Object Type: Article
System: The UNT Digital Library
Energy Demand and Fuel Supply in Developing Countries Brazil,Korea and the Philippines (open access)

Energy Demand and Fuel Supply in Developing Countries Brazil,Korea and the Philippines

None
Date: May 20, 1984
Creator: Sathaye, Jayant A.
Object Type: Report
System: The UNT Digital Library
Suppressed-fission ICF hybrid reactor (open access)

Suppressed-fission ICF hybrid reactor

A suppressed-fission ICF hybrid reactor has been designed to maximize the production of /sup 233/U. In this design, Be is used as a neutron multiplier. An annular array of Be columns surrounds the fusion pulse inside the reaction chember. The Be columns consist of short cylinders of Be joined together with steel snap rings. Vertical holes in the Be carry liquid lithium coolant and steel-clad thorium fuel pins. The lithium coolant is supplied at the top of the chamber, traverses through the Be columns and exits at the bottom. The columns are attached to top and bottom plates in such a way as to tolerate radiation-induced swelling and the vibrations resulting from each fusion pulse. A thin (10 cm) liquid Li fall region protects the Be columns from direct exposure to the X-rays and debris emitted by the fuel capsule. A neutronics study of this design indicates that the specific production of /sup 233/U fuel is increased by operating at relatively large thorium volume fractions. A design at a fertile fuel fraction of 30 vol % produces a total breeding ratio of over 2.1. The /sup 6/Li to /sup 7/Li ratio is adjusted to keep the tritium breeding ratio at …
Date: May 20, 1986
Creator: Hogan, W. J. & Meier, W. R.
Object Type: Article
System: The UNT Digital Library
Progress in the ICF Program at the Lawrence Livermore National Laboratory (open access)

Progress in the ICF Program at the Lawrence Livermore National Laboratory

Experiments using the harmonically converted Nd:glass lasers at the Lawrence Livermore National Laboratory (Novette with 2 to 10 kJ at 0.26 and 0.53 micron and Nova with 30 to 80 kJ at 0.35 and 0.53 micron) have demonstrated favorable coupling of laser light to fusion targets. The coupling of short-wavelength laser light to these plasmas is now well understood and is primarily collisional in nature, in contrast to previous experiments at 1.06 microns and 10 microns, where the coupling was collective. Increased absorption and conversion to x-rays and decreased production of suprathermal electrons was measured with decreasing wavelength. Stimulated Raman scattering was identified as the primary source of the suprathermal electrons. The collisionality of the laser target coupling can be controlled by the proper selection of laser wavelength and target material. The coupling improvements led directly to the demonstration of higher-density ablative implosions of DT fusion fuel. Experiments on Novette demonstrated a better than 100-fold compression of the DT fuel with two-sided illumination. The Nova laser is extending laser-plasma studies to plasmas several times larger than those used on Novette. Recent experiments have produced a yield of over 10/sup 13/ neutrons. Temporally shaped pulses on Nova will be used to …
Date: May 20, 1986
Creator: Hogan, W.J.
Object Type: Article
System: The UNT Digital Library
Fusion-fission hybrid studies in the United States (open access)

Fusion-fission hybrid studies in the United States

Systems and conceptual design studies have been carried out on the following three hybrid types: (1) The fission-suppressed hybrid, which maximizes fissile material produced (Pu or /sup 233/U) per unit of total nuclear power by suppressing the fission process and multiplying neutrons by (n,2n) reactions in materials like beryllium. (2) The fast-fission hybrid, which maximizes fissile material produced per unit of fusion power by maximizing fission of /sup 238/U (Pu is produced) in which twice the fissile atoms per unit of fusion power (but only a third per unit of nuclear power) are made. (3) The power hybrid, which amplifies power in the blanket for power production but does not produce fuel to sell. All three types must sell electrical power to be economical.
Date: May 20, 1986
Creator: Moir, R. W.; Lee, J. D.; Berwald, D. H.; Cheng, E. T.; Delene, J. G. & Jassby, D. L.
Object Type: Article
System: The UNT Digital Library
Angular distributions of target fragments from the reactions of 292 MeV - 25. 2 GeV /sup 12/C with /sup 197/Au and /sup 238/U (open access)

Angular distributions of target fragments from the reactions of 292 MeV - 25. 2 GeV /sup 12/C with /sup 197/Au and /sup 238/U

Angular distributions of target fragments from the reactions of /sup 12/C with /sup 197/Au and /sup 238/U were measured at projectile energies of 292 MeV, 1.0 GeV, 3.0 GeV, 12.0 GeV and 25.2 GeV. The angular distributions of the /sup 197/Au target fragments were all forwardly peaked. Extensively forward peaked angular distributions were observed at the non-relativistic projectile energies (292 MeV, 1.0 GeV). No obvious differences were observed in the angular distributions at the different relativistic projectile energies of 3.0 GeV, 12.0 GeV and 25.2 GeV. The characteristic angular distribution pattern from the relativistic projectile energy experiments was also observed in the non-relativistic energy experiments. Maximum degree of forward-peaking in the angular distributions at each projectile energy was observed at the product mass number (A) around 190 from the 292 MeV projectile energy, at A=180 from 1.0 GeV and at A=175 from 3.0 GeV and 12.0 GeV. In general, two different types of angular distributions were observed in the relativistic projectile energy experiments with the /sup 238/U target. Isotropic angular distributions were observed for the fission product nuclides. The angular distributions of the fission products at the intermediate (292 MeV) energy showed slightly forward- peaked angular distributions. Because of the …
Date: May 20, 1983
Creator: Morita, Y.
Object Type: Report
System: The UNT Digital Library
Advances in Tandem Mirror fusion power reactors (open access)

Advances in Tandem Mirror fusion power reactors

The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and several advanced reactor concepts including the wall-stabilized reactor and the field-reversed mirror. With a novel compact end plug scheme employing octopole stabilization, MINIMARS is expressly designed for short construction times, factory-built modules, and a small (600 MWe) but economic reactor size. We have also configured the design for low radioactive afterheat and inherent/passive safety under LOCA/LOFA conditions, thereby obviating the need for expensive engineered safety systems. In contrast to the complex and expensive double-quadrupole end-cell of the MARS reactor, the compact octopole end-cell of MINIMARS enables ignition to be achieved with much shorter central cell lengths and considerably improves the economy of scale for small (approx.250 to 600 MWe) tandem mirror reactors. Finally, we examine the prospects for realizing the ultimate potential of the tandem mirror with regard to both innovative configurations and novel neutron …
Date: May 20, 1986
Creator: Perkins, L. J. & Logan, B. G.
Object Type: Article
System: The UNT Digital Library
Alternative connections for the large MFTF-B solenoids (open access)

Alternative connections for the large MFTF-B solenoids

The MFTF-B central-cell solenoids are a set of twelve closely coupled, large superconducting magnets with similar but not exactly equal currents. Alternative methods of connecting them to their power supplies and dump resistors are investigated. The circuits are evaluated for operating conditions and fault conditions. The factors considered are the voltage to ground during a dump, short circuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the current induced in coils that remain superconducting when one or more coils quench. The alternative connections include separate power supplies, combined power supplies, individual dump resistors, series dump resistors and combinations of these. A new circuit that contains coupling resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. Another novel circuit, the series circuit with diodes, is discussed in detail.
Date: May 20, 1983
Creator: Owen, E. W.; Shimer, D. W. & Wang, S. T.
Object Type: Report
System: The UNT Digital Library
Design, implementation, and operation of a class based batch queue scheduler for VAX/VMS (open access)

Design, implementation, and operation of a class based batch queue scheduler for VAX/VMS

Fermilab found that the standard VMS batch configuration options were inadequate for the job mix that exists on the Fermilab central computer facility VAX cluster. Accordingly, Fermilab designed and implemented a class based batch queue scheduler. This scheduler makes use of the standard VMS job controller and batch system. Users interact with the scheduler at job submission time by specification of CPU time limits and batch job characteristics. This scheduler allows Fermilab to make efficient use of our large heterogeneous VAX cluster which contains machines ranging from a VAX 780 to a VAX 8800. The scheduler was implemented using the VMS system services $GETQUI and $SNDJBC, without changes to the existing VMS job scheduler. As a result, the scheduler should remain compatible with future VMS versions. This session will discuss the design goals, implementation, and operational experience with Fermilab's class based batch queue scheduler.
Date: May 20, 1988
Creator: Chadwick, K.
Object Type: Article
System: The UNT Digital Library
Position sensitive counter development at the linac (open access)

Position sensitive counter development at the linac

In a novel application of the multiwire proportional counter we have imaged a collimated neutron beam. Although preliminary, the results are of sufficient import to be described here because of the potential wide application of the multiwire proportional counter to Laboratory problems. The counter was operated with a counting gas pressure of 20 Torr; the counting gas was pure C/sub 4/H/sub 10/. The radiator was a /sup 235/U foil. Under these conditions, the counter is (1) relatively insensitive to charged particles (other than fission fragments), (2) insensitive to ..gamma..-radiation, and (3) has an efficiency for the detection of fission fragments independent of incident neutron energy over a wide range of neutron energies.
Date: May 20, 1981
Creator: Becker, J. A.
Object Type: Report
System: The UNT Digital Library
Fermilab Accumulator Magnets Vacuum Chamber Heating System J. Satti & (open access)

Fermilab Accumulator Magnets Vacuum Chamber Heating System J. Satti &

The Fermi National Accelerator Laboratory (Fermilab) is building an accumulator ring to store antiprotons for high energy physics proton-antiproton collisions in the Tevatron accelerator. The accumulator ring, approximately 474 m in circumference, consists of many quadrupole and dipole magnets connected with stainless steel vacuum chambers for beam circulation. The vacuum pressure required is in the low 10{sup -10} Torr range. To reach this pressure, the vacuum chambers are baked at 300 C each time they have been opened to atmospheric pressure. The critical problem is to bake the chambers in the magnets at high temperature without overheating the laminated magnets. Some of the magnets are 5 m long with very restrictive space for the heaters and insulation. An average space of only 7.5 mm around the chambers is available. In this space a heating system has been designed and tested to heat the chamber to 300 C and allow a maximum temperature of 65 C next to the magnet components. This was accomplished by using a heating blanket completely covered with water cooled copper heat sink jacket to protect the magnet from the high temperatures. The design of a final selected heating blanket is discussed. A prototype test results are …
Date: May 20, 1985
Creator: Lee, G.
Object Type: Report
System: The UNT Digital Library
Direct Catalytic Conversion of Methane and Light Hydrocarbon Gases Quarterly Report: Number 6 (open access)

Direct Catalytic Conversion of Methane and Light Hydrocarbon Gases Quarterly Report: Number 6

The goal of this research is to develop catalysts that directly convert methane and light hydrocarbons to intermediates that later can be converted to either liquid fuels or value-added chemicals, as economics dictate. During this reporting period, we synthesized several phthalocyanine catalysts supported on magnesia (MgO) in Task 3. In Task 4 we have tested these catalysts for oxidation of methane and did a number of blank experiments to determine the cause of the low methanol yield we have observed. Magnesia supported catalysts were prepared by first synthesizing the various metal tetrasulfophthalocyanines (TSPCs), converting them to the acid form, and then supporting these complexes on a basic support (MgO) by a neutralization reaction. The metals used were Ru, Pd, Cu, Fe, Co, Mn, and Mo. CoTSPC was also synthesized in zeolite Y using our standard template techniques described in Quarterly Report No. 1. These complexes were examined for catalytic activity in the oxidation of methane. The PdTSPC/MgO had greater activity, and oxidized some of the methane (selectivity of 2.8% from the methane oxidized at 375{degrees}C) to ethane. This is a much lower temperature for this reaction than previously reported in the literature. We also examined the reactivity of various components …
Date: May 20, 1988
Creator: Wilson, Robert B., Jr.; Chan, Yee Wai & Posin, B. M.
Object Type: Report
System: The UNT Digital Library
The Los Alamos Neutron Scattering Center data acquisition system (open access)

The Los Alamos Neutron Scattering Center data acquisition system

The FASTBUS subsystem of the LANSCE data acquisition system consists of a single FASTBUS crate segment with four custom modules and a QPI interface for the VAX. Since experiments at the LANSCE facility always include a time-of-flight parameter for the detected neutron and may optionally include additional position parameters characterizing the event, a time stamp is generated for each event by the Programmable Master Clock (PMC) module. The time and any position information are latched into the Time-Of-Flight buffer (TOF) module. After all events associated with a single neutron burst have been captured in a frame buffer internal to the TOF module, each event is analyzed by the MAPPER module and reduced to a histogram address to increment in the BULKSTORE module. Software access to the histogram is provided through the QPI interface.
Date: May 20, 1987
Creator: Nelson, R. O.; Cort, G.; Gjovig, A.; Goldstone, J. A.; McMillan, D. E.; Ross, J. et al.
Object Type: Article
System: The UNT Digital Library
Potential safety-related incidents with possible applicability to a nuclear fuel reprocessing plant (open access)

Potential safety-related incidents with possible applicability to a nuclear fuel reprocessing plant

The Safety Technology Group is developing methodology that can be used to assess the risk of operating a plant to reprocess spent nuclear fuel. As an early step in the methodology, a preliminary hazards analysis identifies safety-related incidents. In the absence of appropriate safety features, these incidents could lead to significant consequences and risk to onsite personnel or to the public. This report is a compilation of potential safety-related incidents that have been identified in studies at SRL and in safety analyses of various commercially designed reprocessing plants. It is an expanded revision of the version originally published as DP-1558, Published December 1980.
Date: May 20, 1982
Creator: Durant, W. S.; Perkins, W. C.; Lee, R. & Stoddard, D. H.
Object Type: Report
System: The UNT Digital Library
Workshop on system tuning, performance measurement and performance optimization of an RSX11M system (open access)

Workshop on system tuning, performance measurement and performance optimization of an RSX11M system

Topics discussed include thrashing in an RSX11M system - what to do; using solid state disk emulators as the swapping device - performance improvement, performance measurement techniques; capacity planning; bis buffering; and DECNET-11M optimization - performance that can be expected for real environments.
Date: May 20, 1981
Creator: Downward, James G.
Object Type: Article
System: The UNT Digital Library