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263
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210
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126
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111
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81
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29
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A formula for efficiency of fast wave current drive in fusion devices
Fast wave current drive (FWCD) is a principal candidate for non- inductive current drive schemes in reactors. Major experiments are in progress or planned on DIII-D, JET, and Tore-Supra. A theory for FWCD was presented by two of the authors and collaborators. To minimize computations required in transport simulations, and for analytical understanding, it is very useful to have a concise analytical efficiency formula. Fisch and Karney, and Ehst and Karney have obtained empirical formulae that fits numerical results for the Landau limit and Alfven limit; the latter fits results at 1 < Z{sub i} {le} 2. This paper extends a previous numerical study on FWCD at arbitrary frequencies and Z{sub i}. Analytical formulae for FWCD efficiency, valid for all frequencies and Z{sub i}, are derived using the adjoint technique in high and low phase velocity regions. A smooth patching between the two regions produces an analytical formula which is accurate for all frequencies, Z{sub i}, and phase velocities. Comparison with existing results will be discussed. A corollary of the present calculation is that a low phase velocities and in the Landau limit, the efficiency is the same as that calculated from the Lorentz model collision operator.
Date:
June 1, 1992
Creator:
Chiu, S. C.; Harvey, R. W. (General Atomics, San Diego, CA (United States)); Karney, C. F. F. (Princeton Univ., NJ (United States). Plasma Physics Lab.) & Mau, T. K. (California Univ., Los Angeles, CA (United States). School of Engineering and Applied Science)
Object Type:
Article
System:
The UNT Digital Library
CDFTBL: A statistical program for generating cumulative distribution functions from data
This document describes the theory underlying the CDFTBL code and gives details for using the code. The CDFTBL code provides an automated tool for generating a statistical cumulative distribution function that describes a set of field data. The cumulative distribution function is written in the form of a table of probabilities, which can be used in a Monte Carlo computer code. A a specific application, CDFTBL can be used to analyze field data collected for parameters required by the PORMC computer code. Section 2.0 discusses the mathematical basis of the code. Section 3.0 discusses the code structure. Section 4.0 describes the free-format input command language, while Section 5.0 describes in detail the commands to run the program. Section 6.0 provides example program runs, and Section 7.0 provides references. The Appendix provides a program source listing. 11 refs., 2 figs., 19 tabs.
Date:
June 1, 1991
Creator:
Eslinger, P.W. (Pacific Northwest Lab., Richland, WA (United States))
Object Type:
Report
System:
The UNT Digital Library
(Test and gather data on sweep spike combination tillage tool)
This summary presents the data accumulated to date with only brief comment. It is prepared with the intent that the viewers will offer advice on terminology, data presentation, methods and other. The year end analysis will detail changes in the data due to the tillage treatments. The data is incomplete due to equipment problems and time limitations due to the wet fall and early freeze up. The trial was not completed due to our inability to get the Mikkelsen Chisel Plow Shovel (MCP), a 16 inch sweep with an anhydrous knife, to penetrate untilled land. The MCP shovel penetrated to deep on plowed ground and pulled so hard that the front wheels of our JD4440 tractor were jerked off the ground. The Standard Chisel Plow Shovels (SCP), a 16 inch sweep, worked well and the data is included.
Date:
June 19, 1992
Creator:
Lukach, J.
Object Type:
Report
System:
The UNT Digital Library
Advanced high efficiency concentrator cells
This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.
Date:
June 1, 1992
Creator:
Gale, R. (Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center)
Object Type:
Report
System:
The UNT Digital Library
Phase 2 drilling operations at the Long Valley Exploratory Well (LVF 51--20)
This report describes the second drilling phase, completed to a depth of 7588 feet in November 1991, of the Long Valley Exploratory Well near Mammoth Lakes, California. The well in Long Valley Caldera is planned to reach an ultimate depth of 20,000 feet or a bottomhole temperature of 500{degrees}C (whichever comes first). There will be four drilling phases, at least a year apart with scientific experiments in the wellbore between active drilling periods. Phase 1 drilling in 1989 was completed with 20 in. casing from surface to a depth of 2558 ft., and a 3.8 in. core hole was drilled below the shoe to a depth of 2754 in. Phase 2 included a 17-{1/2} in. hole out of the 20 in. shoe, with 13-3/8 in. casing to 6825 ft., and continuous wireline coring below that to 7588 ft. This document comprises a narrative log of the daily activities, the daily drilling reports, mud logger's reports, summary of drilling fluids used, and other miscellaneous records.
Date:
June 1, 1992
Creator:
Finger, J. T. & Jacobson, R. D.
Object Type:
Report
System:
The UNT Digital Library
Molecular biological enhancement of coal biodesulfurization. [Rhodococcus, thiobacillus]
The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotropic bacterium; conduct a batch-mode optimization/analysis of scale-up variables.
Date:
June 14, 1990
Creator:
Litchfield, J. H.; Fry, I.; Wyza, R. E.; Palmer, D. T.; Zupancic, T. J. & Conkle, H. N.
Object Type:
Report
System:
The UNT Digital Library
Assessment and development of an advanced heat pump for recovery of volatile organic compounds
This report documents Phase 1 of a project conducted by Mechanical Technology Incorporated (MTI) for the assessment and development of an advanced heat pump for recovery of VOC solvents from process gas streams. In Phase 1, MTI has evaluated solvent recovery applications within New York State (NYS), identified host sites willing to implement their application, and conducted a preliminary design of the equipment required. The design and applications were evaluated for technical and economic feasibility. The solvent recovery heat pump system concept resulting from the Phase 1 work is one of a mobile unit that would service multiple stationary adsorbers. A large percentage of solvent recovery applications within the state can be serviced by on-site carbon bed adsorbers that are desorbed at frequencies ranging from once per to once per month. In this way, many users can effectively share'' the substantial capital investment associated with the system's reverse Brayton hardware, providing it can be packaged as a mobile unit. In a typical operating scenario, a carbon adsorption module will be located permanently at the industrial site. The SLA will be ducted through the adsorber and the solvents removed, thus eliminating an air emission problem. Prior to VOC breakthrough, by schedule …
Date:
June 1, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Nuclear facility licensing, documentaion, and reviews, and the SP-100 test site experience
The required approvals and permits to test a nuclear facility are extensive. Numerous regulatory requirements result in the preparation of documentation to support the approval process. The principal regulations for the SP-100 Ground Engineering System (GES) include the National Environmental Policy Act, Clean Air Act, and Atomic Energy Act. The documentation prepared for the SP-100 Nuclear Assembly Test (NAT) included an Environmental Assessment, state permit applications, and Safety Analysis Reports. This paper discusses the regulation documentation requirements and the SP-100 NAT Test Site experience. 12 refs., 2 figs., 2 tabs.
Date:
June 1, 1991
Creator:
Cornwell, B. C.; Deobald, T. L. & Bitten, E. J.
Object Type:
Article
System:
The UNT Digital Library
Study of the corrosion rate behavior of ion implanted Fe-based alloys
We report on some studies we have made of the time evolution of the corrosion behavior of ion implanted samples of pure iron, medium carbon steel, and 18-8 Cr-Ni stainless steel. Ti, Cr, Ni, Cu, Mo and Yb were implanted at mean ion energies near 100 keV and at doses up to 1 {times} 10{sup 17} cm{sup {minus}2} using a Mevva metal ion implantation facility. A novel feature of this experiment was the simultaneous implantation with several different implanted species. The implanted samples were immersed in sulfuric acid solution at 40{degrees}C and the corrosion monitored as a function of time. The loss in mass was accurately measured using atomic absorption spectroscopy. The functional dependence of the corrosion behavior was established for all samples. The cumulative mass loss Q is given as a function of time t by Q = At{sup N}, where A and N are parameters; thus the corrosion rate V is given by V = ANt{sup N-1}. A is dominated by the initial mass loss and N reflects the long-time corrosion behavior. The values of the parameters A and N were obtained by a least-squares regression for all the samples investigated. We determined that for the samples investigated …
Date:
June 1, 1991
Creator:
Weiping, Cai; Wei, Tian; Wu Run (Wuhan Iron and Steel Univ., HB (China)); Godechot, X. & Brown, I. (Lawrence Berkeley Lab., CA (United States))
Object Type:
Article
System:
The UNT Digital Library
Control of pyrite surface chemistry in physical coal cleaning
To better understand the surface chemical properties of coal and mineral pyrite, studies on the effect of flotation surfactants (frother and kerosene) on the degree of hydrophobicity have been conducted. The presence of either frother or kerosene enhanced the flotability of coal and mineral pyrite with a corresponding decrease in induction time over the pH range examined. Scanning electron microscopy (SEM) results indicate a correlation exists between the sample surface morphology and crystal structure and the observed hydrophobicity. As a result of the data obtained from the surface characterization studies, controlled surface oxidation was investigated as a possible pyrite rejection scheme in microbubble column flotation.
Date:
June 24, 1992
Creator:
Luttrell, G. H.; Yoon, R. H.; Zachwieja, J. & Lagno, M.
Object Type:
Report
System:
The UNT Digital Library
Fundamental studies of catalytic gasification
Studies of the catalytic steam gasification of carbon solids continued. In this project a considerable number of important findings have been made. Recently limited experimentation has been carried out on the production of C{sub 2} hydrocarbons from methane in the presence of Ca/K/Ni oxide catalysts and of oxygen, carbon and water. The main finding thus far has been that C{sub 2} yields of 10--13% can be obtained at about 600{degrees}C or 150{degrees} lower temperature than described in the literature for similar yields. Work during this quarter was largely concentrated on oxidative methane coupling. Gasification of a petroleum coke is also discussed. 5 tabs.
Date:
June 1, 1991
Creator:
Heinemann, H. & Smorjai, G.A.
Object Type:
Report
System:
The UNT Digital Library
Locked modes and magnetic field errors in MST
In the MST reversed field pinch magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance, the disturbance locks to an impulsive field error generated at a sawtooth crash, the error fields grow monotonically after locking (perhaps due to an unstable interaction between the modes and field error), and over the tens of milliseconds of growth confinement degrades and the discharge eventually terminates. Field error control has been partially successful in eliminating locking.
Date:
June 1, 1992
Creator:
Almagri, A. F.; Assadi, S.; Prager, S. C.; Sarff, J. S. & Kerst, D. W.
Object Type:
Report
System:
The UNT Digital Library
Direct electron absorption of fast waves on the D3-D tokamak
None
Date:
June 1, 1992
Creator:
Petty, C. C.; Pinsker, R. I.; Chiu, S. C.; deGrassie, J. S.; Lohr, J.; Luce, T. C. et al.
Object Type:
Article
System:
The UNT Digital Library
Tests of a model pole assembly for the ALS U5. 0 undulator
The ALS insertion devices must meet very tight requirements in terms of field quality and field strength. Even though the ability to calculate the performance of a hybrid insertion device has improved considerably over the past few years, a model pole was assembled to test the ALS U5.0 undulator geometry and to verify the calculations. The model pole consists of a half period of the periodic structure of the insertion device with mirror plates at the midplane and at the zero-field, half-period planes. A Hall probe was used to measure the vertical component of the field near the midplane of the model as a function of gap and transverse position. Because of the tight field quality requirements the ALS insertion devices are designed to permit several types of correction, including the capability of adding magnetic material or iron at several locations to boost or buck the field. This correction capability was evaluated during our tests. The model is described and details of the test results are discussed, including the fact that the measured peak field is several percent higher than the calculated value, which is based on the measured magnetization of the blocks used in the model. 8 refs., 20 …
Date:
June 1, 1991
Creator:
Hassenzahl, W.V.; Hoyer, E. (Lawrence Berkeley Lab., CA (United States)) & Savoy, R. (Argonne National Lab., IL (United States))
Object Type:
Report
System:
The UNT Digital Library
Development and evaluation of a meter for measuring return line fluid flow rates during drilling
The most costly problem routinely encountered in geothermal drilling is lost circulation, which occurs when drilling fluid is lost to the formation rather than circulating back to the surface. The successful and economical treatment of lost circulation requires the accurate measurement of drilling fluid flow rate both into and out of the well. This report documents the development of a meter for measuring drilling fluid outflow rates in the return line of a drilling rig. The meter employs a rolling counterbalanced float that rides on the surface of the fluid in the return line. The angle of the float pivot arm is sensed with a pendulum potentiometer, and the height of the float is calculated from this measurement. The float height is closely related to the fluid height and, therefore, the flow rate in the line. The prototype rolling float meter was extensively tested under laboratory conditions in the Wellbore Hydraulics Flow Facility; results from these tests were used in the design of the field prototype rolling float meter. The field prototype meter was tested under actual drilling conditions in August and September 1991 at the Long Valley Exploratory Well near Mammoth Lakes, Ca. In addition, the performance of several …
Date:
June 1, 1992
Creator:
Loeppke, G. E.; Schafer, D. M.; Glowka, D. A.; Scott, D. D.; Wernig, M. D. & Wright, E. K.
Object Type:
Report
System:
The UNT Digital Library
Experimental development of nuclear pumped laser candidate for inertial confinement fusion driver
A report is given on progress made during the second year of a three year contract studying the feasibility of nuclear pumping the atomic iodine laser. Experimental results are presented showing efficiencies of 25--38% at converting neutron-induced nuclear reaction energy in the excimer XeBr into UV photons which can be used to pump the laser. Parametric studies were done utilizing the {sup 10}B(n,{alpha}){sup 7}Li reaction, with three bromine donor chemicals, over a range of pressures and mix ratios, to optimize the fluorescence efficiency.
Date:
June 6, 1990
Creator:
Miley, George H.
Object Type:
Report
System:
The UNT Digital Library
Tank 241-A-105 leak assessment
Tank 241-A-105 is one of 149 single shell tanks constructed at Hanford to contain and store highly radioactive wastes originating from the processing of spent nuclear reactor fuel. Radiation detection and temperature monitoring devices installed beneath the tank indicate that several episodes of leakage of waste from the tank have occurred. The aim of this study was to evaluate the previous estimates and reanalyze the data to provide a more accurate estimate of leakage from the tank. The principal conclusions of this study are as follows: Earlier investigators estimated leakage prior to August 1968 at 5,000 to 15,000 gallons. Their estimate appears reasonable. Leakage while the tank was being sluiced (8/68--11/70) probably exceeded 5,000 gallons, but probably did not exceed 30,000 gallons. Insufficient data are available to be more precise. Cooling water added to the tank during the sprinkling phase (11/70 -- 12/78) was approximately 610,000 gallons. Sufficient heat was generated in the tank to evaporate most, and perhaps nearly all, of this water. Radionuclides escaping into the soil under the tank cannot be estimated directly because of many uncertainties. Based on a range of leakage from 10,000 to 45,000 gallons, assumed compositions, and decayed to 1/1/91, radioactivity under the …
Date:
June 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Acceleration using total internal reflection
This report considers the use of a dielectric slab undergoing total internal reflection as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of the dielectric for polarized incident waves. We present an experimental arrangement for testing the performance of the method, using apparatus under construction for the Grating Acceleration experiment at Brookhaven National Laboratory. 13 refs., 4 figs., 2 tabs.
Date:
June 7, 1991
Creator:
Fernow, R.C.
Object Type:
Report
System:
The UNT Digital Library
Inherently safe nuclear-driven internal combustion engines
A family of nuclear driven engines is described in which nuclear energy released by fissioning of uranium or plutonium in a prompt critical assembly is used to heat a working gas. Engine performance is modeled using a code that calculates hydrodynamics, fission energy production, and neutron transport self-consistently. Results are given demonstrating a large negative temperature coefficient that produces self-shutoff of energy production. Reduced fission product inventory and the self-shutoff provide inherent nuclear safety. It is expected that nuclear engine reactor units could be scaled from 100 MW on up. 7 refs., 3 figs.
Date:
June 14, 1991
Creator:
Alesso, P.; Chow, Tze-Show; Condit, R.; Heidrich, J.; Pettibone, J. & Streit, R.
Object Type:
Article
System:
The UNT Digital Library
The Savannah River Site's Groundwater Monitoring Program
This report summarizes the Savannah River Site (SRS) groundwater monitoring program conducted in the fourth quarter of 1990. It includes the analytical data, field data, well activity data, and other documentation for this program, provides a record of the program's activities and rationale, and serves as an official document of the analytical results. The groundwater monitoring program includes the following activities: installation, maintenance, and abandonment of monitoring wells, environmental soil borings, development of the sampling and analytical schedule, collection and analyses of groundwater samples, review of analytical and other data, maintenance of the databases containing groundwater monitoring data, quality assurance (QA) evaluations of laboratory performance, and reports of results to waste-site facility custodians and to the Environmental Protection Section (EPS) of EPD.
Date:
June 18, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Energetics and statistics of order in alloys with application to oxide superconductors
Now that first-principles calculations of ordering transformations are becoming increasingly accurate, the deficiencies of earlier mean field methods are becoming increasingly apparent. New techniques, based on cluster expansions, are now alleviating many of the earlier problems and are producing very satisfactory results. These ideas will be illustrated for the case of oxygen ordering in the YBa{sub 2}Cu{sub 3}O{sub z} superconducting compound, for which a very simple two-dimensional Ising model has been developed. The model features nearest-neighbor repulsive effective pair interactions and anisotropic (attractive/repulsive) next-nearest-neighbor interactions. CVM (cluster variation method) calculations based on this model have produced a phase diagram in remarkable agreement with experimentally determined phase boundaries. Monte Carlo simulations have confirmed the validity of the model and have provided a rationalization for the influence of oxygen order on the value of {Tc} (superconducting transition temperature) in off-stoichiometric compounds. 46 refs., 4 figs.
Date:
June 1, 1991
Creator:
de Fontaine, D. (Lawrence Livermore National Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering); Ceder, G. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering) & Asta, M. (Lawrence Livermore National Lab., CA (United States) California Univ., Berkeley, CA (United States).
Object Type:
Article
System:
The UNT Digital Library
High temperature ceramic membrane reactors for coal liquid upgrading
In this project we well evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated. (VC)
Date:
June 19, 1992
Creator:
Tsotsis, T.T.
Object Type:
Report
System:
The UNT Digital Library
Benchmark field study of deep neutron penetration
A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field are described with emphasis on neutron source characteristics and room return background. The single material chosen for the first benchmark, LATAN-1, is a steel representative of Light Water Reactor (LWR) Pressure Vessels (PV). Also included is a brief description of the Little Boy replica, a critical reactor assembly designed to mimic the radiation doses from the atomic bomb dropped on Hiroshima, and its us in neutron spectrometry. 18 refs.
Date:
June 10, 1991
Creator:
Morgan, J. F.; Sale, K. (Lawrence Livermore National Lab., CA (USA) ); Gold, R.; Roberts, J. H. & Preston, C. C. (Metrology Control Corp., Richland, WA (USA) )
Object Type:
Article
System:
The UNT Digital Library
Top physics at CDF
We present here preliminary results of an extension of our already published search for the top quark. The search is based on a data sample collected during the 1988--1989 run of the Fermilab Tevatron Collider corresponding to an integrated luminosity of 4.4 pb {sup {minus}1}. We find no evidence for top quark production and we establish preliminary limits on the t-tbar production cross section as a function of the top mass (M{sub top}) in p-pbar collisions at {radical}s = 1.8 TeV. Using theoretical expectations for this cross-section, we translate these limits into a preliminary lower limit for M{sub top} of 89 Gev/c{sup 2} at the 95% confidence level. 12 refs., 3 figs. (CL)
Date:
June 1, 1991
Creator:
Campagnari, C.
Object Type:
Article
System:
The UNT Digital Library