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A unified theory of resonant excitation of kinetic ballooning modes by energetic ions/alpha particles in tokamaks
A complete theory of wave-particle interactions is presented whereby both circulating and trapped energetic ions can destabilize kinetic ballooning modes in tokamaks. Four qualitatively different types of resonances, involving wave-precessional drift, wave-transit, wave-bounce, and precessional drift-bounce interactions, are identified, and the destabilization potential of each is assessed. For a characteristic slowing-down distribution function, the dominant interaction is that which taps those resonant ions with the highest energy. Implications of the theory for present and future generation fusion experiments are discussed. 16 refs.
Date:
October 1, 1991
Creator:
Biglari, H. & Chen, L.
Object Type:
Report
System:
The UNT Digital Library
Non-linear instability of DIII-D to error fields
Otherwise stable DIII-D discharges can become nonlinearly unstable to locked modes and disrupt when subjected to resonant m = 2, n = 1 error field caused by irregular poloidal field coils, i.e. intrinsic field errors. Instability is observed in DIII-D when the magnitude of the radial component of the m = 2, n = 1 error field with respect to the toroidal field is B{sub r21}/B{sub T} of about 1.7 {times} 10{sup {minus}4}. The locked modes triggered by an external error field are aligned with the static error field and the plasma fluid rotation ceases as a result of the growth of the mode. The triggered locked modes are the precursors of the subsequent plasma disruption. The use of an n = 1 coil'' to partially cancel intrinsic errors, or to increase them, results in a significantly expanded, or reduced, stable operating parameter space. Precise error field measurements have allowed the design of an improved correction coil for DIII-D, the C-coil'', which could further cancel error fields and help to avoid disruptive locked modes. 6 refs., 4 figs.
Date:
October 1, 1991
Creator:
La Haye, R. J. & Scoville, J. T.
Object Type:
Article
System:
The UNT Digital Library
Fifth high-energy heavy-ion study
This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base. (GHT)
Date:
October 1, 1981
Creator:
unknown
Object Type:
Article
System:
The UNT Digital Library
Radon alpha-track survey of a potential geothermal resource area. [Buffalo Valley, Nevada]
None
Date:
October 1, 1974
Creator:
Wollenberg, H.A.
Object Type:
Report
System:
The UNT Digital Library
(Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)
This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.
Date:
October 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Intermediate-depth geothermal temperature study. Gradient holes: 11-33 and 63-33, Soda Lake, NV
During 1979, Chevron Resources Company drilled two 2000 ft holes near Soda Lake in the Nevada Carson Sink area to obtain subsurface data for inclusion in the US Department of Energy's Northern Basin and Range geothermal reservoir assessment program. Drilling information together with detailed lithologic, geophysical and temperature log data were compiled for each hole and is summarized in this report. Maximum stabilized temperatures of 297/sup 0/F and 367/sup 0/F were encountered at total depth in each of the holes, respectively.
Date:
October 1, 1979
Creator:
Hill, D.G.
Object Type:
Report
System:
The UNT Digital Library
Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979
The feasibility of modifying the IGT capillary viscometer for the measurement of methane-saturated brines at 10,000 psi and 200/sup 0/C was evaluated. The viscometer was cleaned, modified, reassembled and pressure treated. The density cells were calibrated to a precision of approximately 7%. The viscosity of pure value was measured and the best value obtained was 6% below values reported in the literature. The operation of the viscometer was time-consuming and required meticulous cleaning between experiments. Some corrosion at the mercury surface interfered with the efficient operation of the timing device. Other problems were encountered due to gas bubbles trapped in the capillary flow path. Consequently, data on methane-saturated brine could not be obtained within the funding limitations of this program. It is concluded that further work on the existing viscometer would not be cost-effective.
Date:
October 1, 1980
Creator:
Rockar, E. & Randolph, P.
Object Type:
Report
System:
The UNT Digital Library
Two-photon physics
A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes.
Date:
October 1, 1981
Creator:
Bardeen, W.A.
Object Type:
Article
System:
The UNT Digital Library
Final Report of Modeling of CWM Droplet Combustion
The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This process is assumed to be kinetically controlled. Water vaporization and devolatilization processes are modeled by using a hybrid Eulerian-Lagrangian method to obtain the properties of the gas-phase and the condensed-phase. An explicit finite difference scheme is used to solve the Eulerian gas-phase equation where as a Runga-Kutta scheme is employed to solve the Lagrangian condensed-phase equations. The predicted characteristic times for water vaporization is in good agreement with values proposed in the literature. At the present time there is insufficient data to draw any conclusions on the model. Methods are proposed to refine the simple kinetic model which takes into account pore diffusion and mass transfer for devolatilization and char oxidation. 9 references, 12 figures.
Date:
October 1, 1983
Creator:
Pandalai, Krish; Aggarwal, Suresh & Sirignano, William
Object Type:
Report
System:
The UNT Digital Library
Effect of fuel recycling on radioactivity and thermal power of high-level wastes
The radioactivity and thermal power of high-level and plutonium-bearing wastes from the nuclear fuel cycle have been calculated for the years 1975 to 2005 using the rate of generation of such wastes projected for the Generic Environmental Statement on Mixed Oxide Fuel (NUREG-0002). Three modes of fuel recycle are considered: (1) no recycle, (2) uranium recycle, and (3) prompt uranium and plutonium recycle. These cases are compared with a respect to radioactivity and thermal power of the generated waste, the waste shipments, and the accumulated inventories at reactor sites, reprocessing facilities, and ultimate disposal sites.
Date:
October 1, 1977
Creator:
Wachter, J.W.
Object Type:
Report
System:
The UNT Digital Library
The interpretation of reflectometry measurements of plasma fluctuations
Wave reflections from density fluctuations with magnitudes and frequencies typical of drift waves have been investigated. Both drift waves and the reflected phase and amplitude depend on the density gradient scale length, and this common feature implies that both the angular deviation of a normally propagating wave and the phase change on reflection are of order unity. Thus the surface will always appear rough'' and amplitude variations will always be large. For smaller amplitude waves numerical solutions of the one dimensional full wave equation for the propagation near cutoff frequencies has been used to show how to interpret reflectometry measurements. For density perturbations with wavelengths near the density scale length, the external fluctuating phase can be simply interpreted in terms of a fluctuating density near the cutoff layer. However, the amplitude of the phase response falls substantially as the fluctuation wavelength, {Lambda}, approaches the free space wavelength of the reflected wave, {lambda}{sub o}, and the location of the maximum response moves out in front of the cutoff layer following the wave matching condition k{sub {Lambda}} = 2k {approx} 2{eta}(x)k{sub 0}. Similarly, correlation measurements of density fluctuations from probe waves of different wavelengths are shown to be limited to about four …
Date:
October 1, 1991
Creator:
Bretz, N.
Object Type:
Report
System:
The UNT Digital Library
Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids
On September 1, 1989 work was initiated on a project to extend the available vapor-liquid equilibrium (VLE) model for coal fluids to allow satisfactory predictions of excess enthalpies of coal liquids at high pressures. The available vapor liquid equilibrium model was developed with support from previous grant from DOE-PETC (Grant no. DE-FG22-89PC90541). The current project also involves measurement of some model compound VLE data and chromatographic characterization of coal liquids for distribution of heteroatoms. A computational thermodynamic model for VLE, excess enthalpies and heat capacities of coal derived liquids has been developed. The model uses the modified UNIFAC correlation for the liquid phase. Some unavailable UNIFAC interactions parameters have been regressed from experimental VLE and excess enthalpy data. The computations are carried out using the method of continuous thermodynamics. Mode is used to derive interesting conclusions on the effect of oxygen, nitrogen, and sulfur heteroatoms on the thermodynamic properties of coal liquids. When compared with limited experimental data available for coal liquids the model shows good agreement. Some progress has been made on binary VLE measurements and size exclusion chromatography of coal liquids.
Date:
October 1, 1991
Creator:
Kabadi, V. N.
Object Type:
Report
System:
The UNT Digital Library
High-energy proton radiation damage of high-purity germanium detectors
Motivated by their applicability to gamma-ray spectroscopy experiments in space, quantitative studies of radiation damage effects in high-purity germanium detectors due to high-energy charged particles have been initiated with the irradiation by 6 GeV/c protons of two 1.0 cm thick planar detectors maintained at 88/sup 0/K. The threshold for resolution degradation and the annealing characteristics differs markedly from those previously observed for detectors irradiated by fast neutrons. Under proton bombardment, degradation in the energy resolution was found to begin below 7 x 10/sup 7/ protons/cm/sup 2/, and increased proportionately in both detectors until the experiment was terminated at a total flux of 5.7 x 10/sup 8/ protons/cm/sup 2/, equivalent to about a six year exposure to cosmic-ray protons in space. At the end of the irradiation, the FWHM resolution measured at 1332 keV stood at 8.5 and 13.6 keV, with both detectors of only marginal utility as a spectrometer due to the severe tailing caused by charge trapping. The two detectors displayed a significant difference in proton damage sensitivity, which is consistent with fast neutron damage effects. To ensure that detector variability did not influence the comparison of proton- and neutron-induced damage effects, one of the detectors had been used …
Date:
October 1, 1977
Creator:
Pehl, R.H.; Varnell, L.S. & Metzger, A.E.
Object Type:
Article
System:
The UNT Digital Library
Laser annealing of ion implanted CZ silicon for solar cell junction formation. Quarterly report No. 2
Results on a contract to evaluate the merits of large spot size pulsed laser annealing of ion implanted silicon wafers for junction formation in solar cells are reported. Investigations on homogenization of the laser beam were continued. In addition to the 30 mm diameter fused silica rod with a 90/sup 0/ bend configuration, quartz tubes were obtained and briefly tried. Best results were obtained with the rod homogenizer. Laser annealing experimentation resulted in complete recrystallization of ion implanted silicon substrates as confirmed by TEM and RBS analysis. Single pulse laser annealed, functional cells (2 x 2cm) were fabricated using varying process conditions, yielding conversion efficiencies predominantly in the 13% to slightly less than 15%.
Date:
October 1, 1980
Creator:
Katzeff, J. S.
Object Type:
Report
System:
The UNT Digital Library
Radioactive Waste Disposal System Periodic Radiation Monitoring Survey. Core I, Seed 1. Test Results (T-612075). Section 2
Radiation levels were determined at all permanently installed monitored points in the disposal area. Radiation levels were found to be generally higher than those measured during the previous test but within Health Physics limitations. (J.R.D.)
Date:
October 1, 1960
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Thermal energy storage for power generation
Studies strongly indicate that the United States will face widespread electrical power constraints in the 1990s, with most regions of the country experiencing capacity shortages by the year 2000. In many cases, the demand for increased power will occur during intermediate and peak demand periods. Much of this demand is expected to be met by oil- and natural gas-fired Brayton cycle turbines and combined-cycle plants. While natural gas is currently plentiful and reasonably priced, the availability of an economical long-term coal-fired option for peak and intermediate load power generation will give electric power utilities an option in case either the availability or cost of natural gas should deteriorate. 54 refs., 5 figs., 17 tabs.
Date:
October 1, 1989
Creator:
Drost, M. K.; Antoniak, Z. I.; Brown, D. R. & Sathyanarayana, K.
Object Type:
Report
System:
The UNT Digital Library
Calorimetric and optical beam diagnostics on the LBL 120-keV neutral beam test facility
The 120-keV Neutral Beam Test Facility at LBL is fitted with several types of instrumentation to determine the properties of the 10- to 15-A hydrogen and deuterium beams produced in this facility. These include a neutral particle dump for measuring the temperature profile generated by the beam, and a fixed and a moveable ion dump to measure the temperature profiles generated by the various ion components after they have been swept out of the neutral beam by a bending magnet. These several dumps provide enough information to determine the power density profiles and divergences of the neutral beam and the various ion beams for comparison with theoretical calculations, the beam composition, and the neutralization efficiency. The optical beam diagnostic consists of a high-resolution spectrometer coupled with a commercial optical multichannel analyzer. These instruments analyze Doppler-shifted optical radiation from the moving neutral atoms in the beam. Analysis of data so obtained provides the aiming directions and divergences of the various energy components in the neutral beam, as well as the beam composition.
Date:
October 1, 1977
Creator:
Burrell, C. F.; Cooper, W. S.; Steele, W. F. & Smith, R. R.
Object Type:
Article
System:
The UNT Digital Library
Continuing development of the DEROB system. Quarterly report, July 1, 1980-September 30, 1980
The last module of the DEROB System has been reprogrammed and recoded in an effort to reduce the computational time and cost associated with using DEROB. Some preliminary tests have been carried out on the new program, and the tentative results show that the time of execution can be reduced anywhere from 7% to 40% of the time required by the previous version of DEROB. The variability in the improvement arises from the options specified by the user. Additional tests are being carried out to debug the program. When these are completed, a copy of the new code will be sent to the technical monitors at SERI. This report outlines the structure of the new program, derives the general form of the heat transfer equations used in this new version, and describes the properties of the convergence accelerator derived for this new version of DEROB.
Date:
October 1, 1980
Creator:
Arumi-Noe, F
Object Type:
Report
System:
The UNT Digital Library
STUDIES IN MICROMERITICS. II. THE DEPOSITION OF PARTICLES IN CIRCULAR CONDUITS DUE TO THERMAL GRADIENTS
The deposition of particles from turbulent gas streams due to thermal gradients was predicted using a simplified flow medel. In the medels particle concentration was assumed constant in the turbulent region. The particle deposition velocity was taken to be the radial velocity of thermal - repulsion in the laminar sublayer. Temperature gradients in the laminar sublayer were calculated for constant wall temperature using the Reynoldss analogy. The loss magnilude of suspended particles from loss due to thermal deposition is not generally greats and is most important for submicron particles. (auth)
Date:
October 1, 1961
Creator:
Postma, A.K.
Object Type:
Report
System:
The UNT Digital Library
Analytical model for a vertical buoyant jet
An analytical model for a round and two-dimensional turbulent buoyant jet which is discharged vertically into a stagnant ambient is developed. The buoyant jet is considered to have three separate zone models which are matched to form a complete solution. The velocity field is determined for the entire jet and plume regions by the use of an eddy viscosity which varies along the axis of the jet. The centerline decay of buoyancy is determined throughout and the results are compared to existing numerical codes. The model is applied to the disposal of carbon dioxide enriched seawater. The results can be used to provide design information for minimizing or maximizing the dilution of a discharge by the receiving environment.
Date:
October 1, 1980
Creator:
Lee, D. W.
Object Type:
Report
System:
The UNT Digital Library
Research in theoretical nuclear physics
The work done during the past year covers three separate areas, low energy nuclear reactions intermediate energy physics, and nuclear structure studies. This manuscript summarizes our achievements made in these three areas.
Date:
October 1, 1991
Creator:
Udagawa, T.
Object Type:
Report
System:
The UNT Digital Library
Nuclear Battery-Thermocouple Type Summary Report
The potential usefulness of approximately 1300 radioactive isotopes as a heat source for the thermoelectric generator was investigated. Only 47 were found to have the proper characteristics of high specific activity and usable haif-life combined with an easily absorbable radiation. These isotopes are discussed showing possible sources of supply, the hazards involved, and the expected performance. Three large Po/sup 210/ heat sources were designed and constructed (for battery use), including one for the SNAP III generator. One small Tl/sup 204/ test heat source was made by irradiation. Eight thermoelectric generators were developed and two of these were used as thermoelectric batteries. Theoretical equations for non-semiconductor thermoelectric materials and experimental measurements to verify the Thompson and Peltier effects are given. (auth)
Date:
October 1, 1960
Creator:
Blanke, B. C.; Birden, J. H.; Jordan, K. C. & Murphy, E. L.
Object Type:
Report
System:
The UNT Digital Library
Electrolytic Dissolution of Power Reactor Fuels in Nitric Acid
The electrolytic oxidation in nitric acid of stainless steel, zirconium, Zircaloy-2, zirconium- uranium alloy, aluminum, and uranium - molybdenum alloy was demonstrated on a laboratory scale. The rate of chemical dissolution of UO/ sub 2/ in nitric acid was measured. Corrosion of stainless steel by these dissolver solutions was measured and found to be negligible. Electrolytic dissolution was demonstrated to be a practical technique for the first step in processing fuel elements of several types of power reactors. (auth)
Date:
October 1, 1961
Creator:
Clark, A. T., Jr.; Meyer, L. H.; Owen, J. H. & Rust, F. G.
Object Type:
Report
System:
The UNT Digital Library
A comparison of spanwise aerodynamic loads estimated from measured bending moments versus direct pressure measurements on horizontal axis wind turbine blades
Two methods can be used to determine aerodynamic loads on a rotating wind turbine blade. The first is to make direct pressure measurements on the blade surface. This is a difficult process requiring costly pressure instrumentation. The second method uses measured flap bending moments in conjunction with analytical techniques to estimate airloads. This method, called ALEST, was originally developed for use on helicopter rotors and was modified for use on horizontal axis wind turbine blades. Estimating airloads using flap bending moments in much simpler and less costly because measurements can be made with conventional strain gages and equipment. This paper presents results of airload estimates obtained using both methods under a variety of operating conditions. Insights on the limitations and usefulness of the ALEST bending moment technique are also included. 10 refs., 6 figs.
Date:
October 1, 1991
Creator:
Simms, D A & Butterfield, C P
Object Type:
Article
System:
The UNT Digital Library