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Recent Results from a Folded Waveguide ICRF Antenna Development Project (open access)

Recent Results from a Folded Waveguide ICRF Antenna Development Project

Preliminary high power tests have been performed on a folded waveguide (FWG) ICRF launcher with a curved coupling faceplate installed. Two alternative faceplate configurations have been built and tested at low power and will be tested at high power in the near future. The new designs include a dipole plate which provides a 0-<font face="symbol">p</font> launch spectrum and a more transparent, flexible monopole face plate configuration. This FWG design is a 12 vane, 57 MHz design with a 0.31 m square cross section. The FWG can be installed with either fast wave or ion-Bernstein wave polarization and can also be retracted behind a vacuum isolation valve. A 1 x 4 FWG array optimized for fast wave current drive on DIII-D has been conceptualized.
Date: April 12, 1999
Creator: Baity, F. W.; Barber, G. C.; Bigelow, T. S.; Carter, M. D.; Fadnek, A.; Ryan, P. M. et al.
Object Type: Article
System: The UNT Digital Library
Toroidal Effects on ICRF Heating and Current Drive (open access)

Toroidal Effects on ICRF Heating and Current Drive

Numerical studies, performed with the Monte-Carlo code FIDO [1], of the evolution of the resonant-ion distribution function in the presence of ICRH in toroidal geometry are presented. In particular it is pointed out how the absorption of toroidal momentum from a wave field with finite parallel wave numbers causes spatial drift and diffusion, which together with the finite orbit widths of the tail ions is shown to have a large effect on the temperature profile of the resonant ion species and also to cause losses of high-energy ions to the wall [2]. Furthermore, it is found that the finite orbit width and the inward drift occuring for negative parallel wave numbers [3] each give rise to a new mechanism of minority-ion cyclotron current drive as compared to earlier models where the drift orbits of the resonant ions are confined to the magnetic flux surfaces. For high levels of coupled power these new mechanisms are found to be the dominating ones [4,5].
Date: April 12, 1999
Creator: Carlsson, J.; Hedin, J. & Hellsten, T.
Object Type: Article
System: The UNT Digital Library
Los Alamos National Laboratory (LANL) Design Criteria for PFP Stabilization of Polycubes Project C-227 (open access)

Los Alamos National Laboratory (LANL) Design Criteria for PFP Stabilization of Polycubes Project C-227

This document provides the design criteria for the Los Alamos National Laboratory design of a thermal stabilization process for polycubes stored at PFP.
Date: April 12, 1999
Creator: RISENMAY, H.R.
Object Type: Report
System: The UNT Digital Library
Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt. (open access)

Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt.

Stable isotope and tritium analyses of shallow ground waters in the Eastern Desert of Egypt showed that the waters were derived largely by evaporation of regional precipitation and at least partly from precipitation in the past 45 y. To estimate the ground water recharge rate, we developed an integrated hydrologic model based on satellite data, geologic maps, infiltration parameters, and spatial rainfall distribution. Modeling indicated that during a severe 1994 storm, recharge through transmission loss in Wadi El-Tarfa was 21% of the precipitation volume. From archival precipitation data, we estimate that the annual recharge rate for the El-Tarfa alluvial aquifer is 4.7 x 10{sup 6} m{sup 3}. Implications for the use of renewable ground waters in arid areas of Egypt and in neighboring countries are clear.
Date: April 12, 2002
Creator: Sultan, M.; Gheith, H.; Sturchio, N. C.; El Alfy, Z. & Danishwar, S.
Object Type: Article
System: The UNT Digital Library
Radiation Transport Calculations on Unstructured Grids Using a Spatially Decomposed and Threaded Algorithm (open access)

Radiation Transport Calculations on Unstructured Grids Using a Spatially Decomposed and Threaded Algorithm

We consider the solution of time-dependent, energy-dependent, discrete ordinates, and nonlinear radiative transfer problems on three-dimensional unstructured spatial grids. We discuss the solution of this class of transport problems, using the code TETON, on large distributed-memory multinode computers having multiple processors per ''node'' (e.g. the IBM-SP). We discuss the use of both spatial decomposition using message passing between ''nodes'' and a threading algorithm in angle on each ''node''. We present timing studies to show how this algorithm scales to hundreds and thousands of processors. We also present an energy group ''batching'' algorithm that greatly enhances cache performance. Our conclusion, after considering cache performance, storage limitations and dependencies inherent in the physics, is that a model that uses a combination of message-passing and threading is superior to one that uses message-passing alone. We present numerical evidence to support our conclusion.
Date: April 12, 1999
Creator: Nemanic, M K & Nowak, P
Object Type: Article
System: The UNT Digital Library
Carbon Transport and Corrosion in High-Temperature Gas-Cooled Reactors (open access)

Carbon Transport and Corrosion in High-Temperature Gas-Cooled Reactors

It is noted that in high-temperature He-cooled graphite reactors, sufficiently high levels of gaseous impurities can lead to transport and corrosion effects. The possible effects of these reactions in graphite-moderated reactors designed to operate at a He-coolant pressure of a about 20 atm. were investigated. Results are included on C transport, steam-graphite reactions, and deposition of C on surfaces. (J.R.D.)
Date: April 12, 1962
Creator: Zumwalt, L. R.; Burnette, R. D. & Riedinger, A. B.
Object Type: Report
System: The UNT Digital Library
DESALINATION OF SEA WATER (open access)

DESALINATION OF SEA WATER

None
Date: April 12, 1965
Creator: Harty, H.
Object Type: Report
System: The UNT Digital Library
RESULTS OF PRELIMINARY NUCLEAR CALCULATIONS FOR A HOMOGENEOUS RESEARCH REACTOR (open access)

RESULTS OF PRELIMINARY NUCLEAR CALCULATIONS FOR A HOMOGENEOUS RESEARCH REACTOR

Critical mass, fuel concentration, power, maximum power density, and wall power density were obtained for bare spherical reactors having diameters of 8, 10, 11, and 12 ft, operating at 20, 100, 2OO, and 300 deg C. (L.T.W.)
Date: April 12, 1956
Creator: Nestor, C. W. Jr.
Object Type: Report
System: The UNT Digital Library
DIVISION OF METALLURGY REPORT FOR MONTH OF MARCH 1945 (open access)

DIVISION OF METALLURGY REPORT FOR MONTH OF MARCH 1945

None
Date: April 12, 1945
Creator: unknown
Object Type: Report
System: The UNT Digital Library
PHASE III FUEL SAMPLE IRRADIATION. IRRADIATION REQUEST ORNL-21 (open access)

PHASE III FUEL SAMPLE IRRADIATION. IRRADIATION REQUEST ORNL-21

None
Date: April 12, 1956
Creator: Neill, F.H. & Waugh, R.C.
Object Type: Report
System: The UNT Digital Library
HEAT-TRANSFER EXPERIMENTS ON A PROPOSED FUEL ASSEMBLY FOR THE EXPERIMENTAL GAS COOLED REACTOR. SECTION II FO FUEL-ASSEMBLY HEAT-TRANSFER AND CHANNEL PRESSURE-DROP EXPERIMENT FOR THE EGCR RESEARCH AND DEVELOPMENT PROGRAM (open access)

HEAT-TRANSFER EXPERIMENTS ON A PROPOSED FUEL ASSEMBLY FOR THE EXPERIMENTAL GAS COOLED REACTOR. SECTION II FO FUEL-ASSEMBLY HEAT-TRANSFER AND CHANNEL PRESSURE-DROP EXPERIMENT FOR THE EGCR RESEARCH AND DEVELOPMENT PROGRAM

Heat-transfer data are presented for the Experimental Gas Cooled Reactor Title I seven-rod fuel-assembly design. The effect on heat transfer of (1) the radial location of the outer six rods of the seven-fuel-rod cluster and of (2) the addition of helical-finned spacers at the midpoint of each of the seven fuel rods is discussed. The heattransfer data were obtained to verify preliminary general assumptions pertaining to the heat-transfer characteristics of the seven- rod fuel-assembly design and to obtain local heat-transfer correlations. The heat-transfer tests were performed at near-atmospheric pressure using air as the coolant medium. Plots and equations of heattransfer correlations over a Reynolds Number range from 12,000 to 80,000 are included. The test set-up and test procedure are also described. (auth)
Date: April 12, 1960
Creator: Beaudoin, C.L. & Higgins, R.M.
Object Type: Report
System: The UNT Digital Library
Thermal annealing of irradiated LiH (open access)

Thermal annealing of irradiated LiH

None
Date: April 12, 1973
Creator: Leider, H. R.; Teas, V. & Griffith, C. M.
Object Type: Report
System: The UNT Digital Library
Sodium Fires and the Release Characteristics of Particulates and Fission Products (open access)

Sodium Fires and the Release Characteristics of Particulates and Fission Products

None
Date: April 12, 1965
Creator: Lauben, G. N.; Koontz, R. L. & Jarrett, A. A.
Object Type: Report
System: The UNT Digital Library
Internal Symmetry and Relativistic Wave Functions (open access)

Internal Symmetry and Relativistic Wave Functions

None
Date: April 12, 1965
Creator: Critchfield, C.L.
Object Type: Article
System: The UNT Digital Library
REMOVAL OF LOW-LEVEL RADIOACTIVE WASTES BY A SANITARY WATER TREATMENT PROCESS (open access)

REMOVAL OF LOW-LEVEL RADIOACTIVE WASTES BY A SANITARY WATER TREATMENT PROCESS

None
Date: April 12, 1966
Creator: Schultz, N.B.
Object Type: Report
System: The UNT Digital Library
Dynamic heat and moisture transport and baroclinic adjustment (open access)

Dynamic heat and moisture transport and baroclinic adjustment

In connection with the authors work on the apparent Iris Effect, they have acquired 2 years of additional data, and are redoing their analysis with the larger amount of data. So far, the results duplicate earlier results with greater statistical significance. They have also responded (successfully) to a number of criticisms of the initial publication. In particular, while differing estimates of cloudy and clear emissivity may be correct, they have shown that they reduce feedback factors by no more than 20%. The resulting feedback factors remain negative and large. Moreover, current data analyses suggest that the earlier estimates may be low for other reasons. They have also shown that all cloudy regions in the region covered by the GMS satellite are convective in origin. They are, however, continuing their work on an improved measure of cumulus activity. In particular, they are using TRMM data to determine thresholds in the T11 channel of GMS that are functions of time, position and SST. They have confirmed that the previous results had a very high statistical significance. However, they expect that the use of the improved measure of cumulus will improve this still further. They have completed their study of the possible reconciliation …
Date: April 12, 2002
Creator: Lindzen, Richard S.
Object Type: Report
System: The UNT Digital Library
Radiation Laboratory quarterly report, January 1, 1978--March 31, 1978. NDRL--1877 (open access)

Radiation Laboratory quarterly report, January 1, 1978--March 31, 1978. NDRL--1877

Progress in various studies is reported including studies on: vapor phase structures of inorganic salts; solvated electrons; exchange perturbation theory for many-electron interactions; concept of orbital following; calculation of vibrational form factors in electron impact excitation; limiting behavior of molecule-molecule inelastic collision amplitude at zero momentum transfer; partially diffusion-controlled reactions of isolated pair in condensed media; field-dependent mobilities, T-R energy transfer between electronically excited argon and ground-state CO/sub 2/; dose and dose-rate effects in the radiolysis of liquids; coulombically correlated charge-pair distribution and recombination--the role of non-Gaussian diffusion; non-bonded interactions; pulse radiolysis studies of hydrocarbon radical scavenging processes; oxidation of methoxyhydroxycyclohexadienyl radicals by quinones; reaction of hydroxyl radical with phenol; solvent effects on the lifetimes of photogenerated biradicals; oxidation of amines by triplet duroquinone; production of singlet oxygen from excited states of aliphatic ketones; and measurement of electron spin-lattice relaxation times. (LK)
Date: April 12, 1978
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Assuring both quality and creativity in basic research (open access)

Assuring both quality and creativity in basic research

How does one assure that both quality and creativity are obtained in basic research environments QA theoreticians have attempted to develop workable definitions of quality, but in more reflective moments, these definitions often fail to capture the deeper essence of the idea of quality.'' This paper asserts that creativity (as a product of the human mind) is a concrete interface between perfunctory definitions of quality (conformance to specifications) and more philosophical speculations about the nature of quality- related ultimates'' like elegance or beauty. In addition, we describe the distinction between creative ideas and creative acts and highlight one of the major inhibitors of creativity, fear. Finally we show that highly creative people often have an irreverent attitude toward boundaries and established authority, and discuss how one can allow for this when designing a QA program in a basic research environment.
Date: April 12, 1990
Creator: Bodnarczuk, Mark
Object Type: Article
System: The UNT Digital Library
Evaluation and recommendations on U. C. Lawrence Livermore Labortory Quality Assurance Program (open access)

Evaluation and recommendations on U. C. Lawrence Livermore Labortory Quality Assurance Program

A study was conducted of the University of California's Lawrence Livermore Laboratory Quality Assurance Program, which focused on training needs and recommendations tailored to the various on-going programs. Specific attention was directed to an assessment of the quality status for the MFTF facility and the capabilities of assigned quality project engineers. Conclusions and recommendations are presented which not only address the purpose of this study, but extend into other areas to provide insight and needs for a total cost effective application of a quality assurance program.
Date: April 12, 1978
Creator: Carpenter, F. D. & Horner, M. H.
Object Type: Report
System: The UNT Digital Library
Is There Hope for Fusion (open access)

Is There Hope for Fusion

From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs.
Date: April 12, 1990
Creator: Fowler, T. K.
Object Type: Article
System: The UNT Digital Library
Purex pulse column designs for capacity factor of 3.0 to 3.5 (open access)

Purex pulse column designs for capacity factor of 3.0 to 3.5

This memorandum indicates the Purex-Plant pulse-column and pulse- generator revisions which would be required to assure an instantaneous capacity of 25 tons U/day with a 20% capacity safety margin under Purex HW {number_sign}3 Flowsheet conditions. (The use of the Purex HW {number_sign}4 Flowsheet (6) with the revised columns would be expected to increase the capacity to 29 or 30 tons U/day.) The indicated design changes are recorded here for study and for possible reference if need for increased production capacity should arise. No recommendation for adoption at this time is made.
Date: April 12, 1955
Creator: Richardson, G. L.
Object Type: Report
System: The UNT Digital Library
Irradiation Processing Department monthly report, March 1963 (open access)

Irradiation Processing Department monthly report, March 1963

This document details activities of the Irradiation Processing Department during the month of August, 1958. A general summary is included at the start of the report, after which the report is divided into the following sections: Research and Engineering Operations; Production and Reactor Operations; Facilities Engineering Operation; Employee Relations Operation; and Financial Operation.
Date: April 12, 1963
Creator: unknown
Object Type: Report
System: The UNT Digital Library
[beta][sup +] decay and cosmic-ray half-lives of [sup 143]Pm and [sup 144]Pm (open access)

[beta][sup +] decay and cosmic-ray half-lives of [sup 143]Pm and [sup 144]Pm

The positron decay partial half-lives of [sup 143]Pm and [sup 144]Pm are needed to assess the viability of elemental Pm as a cosmic-ray clock. We have conducted experiments to measure the [beta][sup +] branches of these isotopes; we find [beta][sup +] branches of these isotopes; we find [beta][sup +] branches of <5.7 [times]10[sup [minus]8] for [sup 143]Pm and <8[times]10[sup [minus] 7] for [sup 144]Pm. Through these branches are a factor of 20 lower than the previous experimental limits, the resulting partial half-lives are still too uncertain to permit any firm conclusions.
Date: April 12, 1993
Creator: Hindi, M.M. (Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics); da Cruz, M.T.F.; Larimer, R.M.; Lesko, K.T.; Norman, E.B. (Lawrence Berkeley Lab., CA (United States)); Sur, B. (Lawrence Berkeley Lab., CA (United States) Queen's Univ., Kingston, ON (Canada). Dept. of Physics) et al.
Object Type: Article
System: The UNT Digital Library
Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads. Technical progress report, 1989 (open access)

Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads. Technical progress report, 1989

This research project involves the design, synthesis and study of molecules which mimic many of the important aspects of photosynthetic electron and energy transfer. Specifically, the molecules are designed to mimic the following aspects of natural photosynthetic multistep electron transfer: electron donation from a tetrapyrrole excited singlet state, electron transfer between tetrapyrroles, electron transfer from tetrapyrroles to quinones, and electron transfer between quinones with different redox properties. In addition, they model carotenoid antenna function in photosynthesis (singlet-singlet energy transfer from carotenoid polyenes to chlorophyll) and carotenoid photoprotection from singlet oxygen damage (triplet-triplet energy transfer from chlorophyll to carotenoids).
Date: April 12, 1989
Creator: unknown
Object Type: Report
System: The UNT Digital Library