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Numerical simulation of a short RFQ resonator using the MAFIA codes
The electrical characteristics of a short (2{beta}{lambda}=0.4 m) resonator with large modulation (m=4) have been studied using the three dimensional codes, MAFIA. The complete resonator, including the modulated electrodes and a complex support structure, has been simulated using {approximately} 350,000 mesh points. Important characteristics studied include the resonant frequency, electric and magnetic fields distributions, quality factor and stored energy. The results of the numerical simulations are compared with the measurements of an actual resonator and analytical approximations. 7 refs., 3 figs., 1 tab.
Date:
January 1, 1991
Creator:
Wang, H.; Ben-Zvi, Ilan; Jain, A.; Paul, P. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics) & Lombardi, A. (Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Lab. Nazionale di Legnaro)
Object Type:
Article
System:
The UNT Digital Library
INEX simulations of the optical performance of the AFEL
The AFEL (Advanced Free-Electron Laser) Project at Los Alamos National Laboratory is presently under construction. The project's goal is to produce a very high-brightness electron beam which will be generated by a photocathode injector and a 20 MeV rf-linac. Initial laser experiments will be performed with a 1-cm-period permanent magnet wiggler which will generate intense optical radiation near a wavelength of 3.7 {mu}m. Future experiments will operate with slotted-tube'' electromagnetic wigglers (formerly called pulsed- wire'' wigglers). Experiments at both fundamental and higher-harmonic wavelengths are planned. This paper presents results of INEX (Integrated Numerical EXperiment) simulations of the optical performance of the AFEL. These simulations use the electron micropulse produced by the accelerator/beam transport code PARMELA in the 3-D FEL simulation code FELEX. 9 refs., 4 figs., 6 tabs.
Date:
January 1, 1991
Creator:
Goldstein, J.C.; Wang, T.S.F. & Sheffield, R.L.
Object Type:
Article
System:
The UNT Digital Library
Decommissioning of a grout- and waste-filled storage tank in the 200 East Area of the Hanford Site
A self-concentrating waste tank located at the Strontium Semiworks Facility in the 200 East Area of the Hanford Site will be decommissioned following waste removal. During a previous decommissioning phase, the tank, thought to be empty, was filled with grout to prevent it from collapsing over time. Several years later, an agitator rod was pulled from within the tank and found to contain significant amounts of radiation, indicating there was still radioactive waste in the tank. Several alternative waste-removal options have been researched and evaluated. It is concluded that before the waste is to be disposed, the grout must be removed. This paper addresses that effort.
Date:
January 1, 1991
Creator:
Marske, S.G.
Object Type:
Article
System:
The UNT Digital Library
Brookhaven highlights for fiscal year 1991, October 1, 1990--September 30, 1991
This report highlights Brookhaven National Laboratory's activities for fiscal year 1991. Topics from the four research divisions: Computing and Communications, Instrumentation, Reactors, and Safety and Environmental Protection are presented. The research programs at Brookhaven are diverse, as is reflected by the nine different scientific departments: Accelerator Development, Alternating Gradient Synchrotron, Applied Science, Biology, Chemistry, Medical, National Synchrotron Light Source, Nuclear Energy, and Physics. Administrative and managerial information about Brookhaven are also disclosed. (GHH)
Date:
January 1, 1991
Creator:
Rowe, M.S.; Cohen, A.; Greenberg, D.; Seubert, L. & Kuper, J.B.H.
Object Type:
Report
System:
The UNT Digital Library
Experimental and theoretical investigations of marine stratocumulus cloud sensitivity to climate parameters using ship-trail clouds
The formation and radiative properties of clouds are poorly parameterized in numerical climate models, especially marine boundary layer clouds. Twomey (1991), after describing the importance of cloud microphysics to the climate problem, states Clearly, many more field measurements and laboratory experiments are called for, rather than endless repetitions of computer simulations that are closely related to each other and parameterize in very similar ways.'' The effort described here is a field experimental effort supported by the Department of Energy under its Quantitative Links'' program. The project is called Ship-Trail Evolution Above High Updraft Naval Targets (SEAHUNT). The purpose of this study is to improve our understanding of the meteorological context in which ship trails and other perturbations to marine boundary layer clouds occur. 8 refs., 6 figs.
Date:
January 1, 1991
Creator:
Porch, W.; Buchwald, M.; Glatzmaier, T.; Kao, C.-Y.; Unruh, W. (Los Alamos National Lab., NM (United States)); Hudson, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurements of Non-Leptonic Weak Decays of Lambda Hypernuclei
Aspects of recent measurements of the mesonic and non-mesonic partial decay rates of {sub {Lambda}}{sup 5}He, and {sub {Lambda}}{sup 12}C are discussed. We comment on what the experiments tell us about the spin-isospin structure of {Delta}S=1 weak interaction in the nuclear environment. 14 refs., 1 fig.
Date:
January 1, 1991
Creator:
Schumacher, Reinhard A.
Object Type:
Article
System:
The UNT Digital Library
The microscopic world: A demonstration of electron microscopy for younger students
None
Date:
January 1, 1991
Creator:
Horton, L. L.
Object Type:
Article
System:
The UNT Digital Library
Alkali sorber (RABSAM), September 1, 1990--August 30, 1991
The objective of this work is to develop a regenerable activated-bauxite sorber alkali monitor that requires no high-temperature/high-pressure sampling line for the reliable in situ measurement of alkali-vapor concentration in the exhaust from the pressurized fluidized-bed combustion of coal. 11 refs., 2 figs., 1 tab.
Date:
January 1, 1991
Creator:
Lee, S. H. D. & Swift, M. W.
Object Type:
Article
System:
The UNT Digital Library
Sonic enhanced ash agglomeration and sulfur capture
The major objective of the Phase 1 test program is to confirm the feasibility of the Manufacturing and Technology Conversion International, Inc. bimodal particle size approach to enhance particulate control by acoustic ash agglomeration. An ancillary objective of the Phase 1 effort is to demonstrate and confirm the feasibility of an acoustic field to enhance sulfur capture by increasing sorbent reactivity. Phase 1 tests are designed to cover the frequency range between 50 and 1400 Hz, establish monomodal baseline performance as a benchmark from which to measure the degree of enhancement expected from the bimodal approach, and, finally, to confirm the effectiveness of low-frequency fields over high-frequency fields for realistic particulate streams. The program will demonstrate the effectiveness of a unique approach which uses a bimodal distribution composed of large sorbent particles and fine fly ash particles to enhance ash agglomeration and sulfur capture at conditions found in direct coal-fired turbines. Under the impact of high-intensity sound waves, sorbent reactivity and utilization, it is theorized, will increase while agglomerates of fly ash and sorbents are formed which are readily collected in commercial cyclones. The work will extend the concept from the demonstration of feasibility (Phase 1), through proof-of-concept (Phase 2) …
Date:
January 1, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Potential for use of high-temperature superconductors in fusion reactors
The present rate of development of high-temperature superconductors (HTSs) is sufficiently rapid that there may be opportunities for their use in contemporary fusion devices such as the International Thermonuclear Experimental Reactor (ITER). The most likely 1application is for delivering power to the superconducting magnets, especially in substituting for the current leads between the temperatures of 4 K and 77K. A second possible application of HTSs is as a liquid-nitrogen-cooled power bus, connecting the power supplies to the magnets, thus reducing the ohmic heating losses over these relatively long cables. A third potential application of HTSs is as an inner high-field winding of the toroidal field coils that would operate at {approx}20 K. While the use of higher temperature magnets offers significant advantages to the reactor system, it is unlikely that tested conductors of this type will be available within the ITER time frame. 23 refs., 2 figs.
Date:
January 1, 1991
Creator:
Hull, J.R.
Object Type:
Article
System:
The UNT Digital Library
NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts
Copper and cobalt are the key elements in syngas conversion catalyst systems used for higher alcohol synthesis. Their proximity and synergy sensitively control the selectivity and efficiency of the process. It is believed that their outer electronic charge distribution which is responsible for their electrical and magnetic properties might be governing their catalytic properties also. To examine the correlation between catalytic and magnetic properties, a series of copper cobalt catalysts (Co/Cu ratio 5:1 to 5:5) with and without a support were prepared. The nuclear quadrupole resonance spectrum of copper and (zero-field) nuclear magnetic resonance spectrum of cobalt and magnetization and hysteresis character of the catalyst were analyzed. Similar to the catalytic results, the magnetic results also were found to be very sensitive to the preparation technique. The results indicate possible electron exchange between copper and cobalt, and cobalt and the support Titania.
Date:
January 14, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Development of a low intensity current monitor system
This report documents the development of a current transformer system used to measure pulsed ion beam currents with a wide dynamic intensity range (nA to mA, and factor of 10{sup 6}). Peak beam currents at the LAMPF accelerator typically range from 100 to nA to 40 mA with pulse widths varying from 30 to 1000 {mu}s. Signal conditioning of the peak current output provides an average current readout with a range of 1 nA to 2 mA, noise of approximately {plus minus}0.5 nA, and accuracy of {plus minus}0.1%. Since the system has proved stable and highly reliable, calibration is performed yearly. The prototype unit was built in 1985 and the final production unit was completed in early 1989. 5 refs., 14 figs.
Date:
January 1, 1991
Creator:
Gallegos, F.R.
Object Type:
Article
System:
The UNT Digital Library
Impact of Nonequilibrium Particle Temperature Considerations on Seeded Coal Combustion Plasma Properties
This past quarter ending 12/30/91, the linear MHD channel simulation model has not only been completely specified but also fully modified to incorporate considerations for nonequilibrium particle temperatures. Testing of the modified model with the initial values from the first submodel (Richter's combustion zone model) and evaluation of the non-equilibrium particle temperature effect on the overall MHD performance is being held up. Reasons for the holdup is the lack of adequate response from Dr. Richter on questions about his nonequilibrium particle temperature model. These questions relate to our insistence to know precisely how the model works and also some review of the source code to ascertain that it is synchronization with our overall analytical development. We have decided to generate initial generator inlet particle parameter values by modifying the CEC code to provide particle parameter values.
Date:
January 1, 1991
Creator:
Oni, A. A.
Object Type:
Report
System:
The UNT Digital Library
Potential effects of maternal contribution on egg and larva population dynamics of striped bass: Integrated individual-based model and directed field sampling
We have used a bioenergetically-driven, individual-based model (IBM) of striped bass as a framework for synthesizing available information on population biology and quantifying, in a relative sense, factors that potentially affect year class success. The IBM has been configured to simulate environmental conditions experienced by several striped bass populations; i.e., in the Potomac River, MD; in Hudson River, NY; in the Santee-Cooper River System, SC, and; in the San Joaquin-Sacramento River System CA. These sites represent extremes in the geographic distribution and thus, environmental variability of striped bass spawning. At each location, data describing the physio-chemical and biological characteristics of the spawning population and nursery area are being collected and synthesized by means of a prioritized, directed field sampling program that is organized by the individual-based recruitment model. Here, we employ the striped bass IBM configured for the Potomac River, MD from spawning into the larval period to evaluate the potential for maternal contribution to affect larva survival and growth. Model simulations in which the size distribution and spawning day of females are altered indicate that larva survival is enhanced (3.3-fold increase) when a high fraction of females in the spawning population are large. Larva stage duration also is less …
Date:
January 1, 1991
Creator:
Cowan, J.H., Jr. (Maryland Univ., Solomons, MD (United States). Chesapeake Biological Lab.) & Rose, K.A. (Oak Ridge National Lab., TN (United States))
Object Type:
Article
System:
The UNT Digital Library
CW 100MW microwave power transfer in space
A proposal is made for high-power microwave transfer in space. The concept consists in a microwave power station integrating a multistage microwave free-electron laser and asymmetric dual-reflector system. Its use in space is discussed. 9 refs., 2 figs., 1 tab.
Date:
January 1, 1991
Creator:
Takayama, K. (Houston Univ., TX (United States). Inst. for Beam Particle Dynamics National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan) Texas Accelerator Center, The Woodlands, TX (United States)); Hiramatsu, S. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)) & Shiho, M. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan))
Object Type:
Article
System:
The UNT Digital Library
Utilization of coal-water fuels in fire-tube boilers
This project is a demonstration for firing coal-water slurry in a fire-tube boiler. It includes design, installation, and demonstration of the slurry firing equipment in a fire-tube boiler at the University of Alabama in Tuscaloosa. The project will be funded by the US Department of Energy with cost sharing from Jim Walter Resources and the University of Alabama. Energy and Environmental Research Corporation is the prime contractor responsible for all respects of the project. The specific objective of this contract is to demonstrate the potential for coal-water fuels to be burned effectively in fire-tube boiler designed for oil or gas. When the results of this project combined with the results of the water-tube slurry testing, a broad data base will exist that will provide valuable information for the retrofit of future boilers. 1 tab.
Date:
January 1, 1991
Creator:
Sommer, T. & Melick, T.
Object Type:
Report
System:
The UNT Digital Library
Optical design and performance of the X25 hybrid wiggler beam line at the NSLS
The X25 beam line at the National Synchrotron Light Source (NSLS) began full-power commissioning in 1990. It extracts radiation from a 27 pole hybrid wiggler, which produces up to 1.8 kW of total power with a peak horizontal density of 450 W/mrad and critical energy of 4.6 keV. The design and performance of the beam line optics are described, in particular the cooling of the first monochromator crystal. 28 refs., 5 figs.
Date:
January 1, 1991
Creator:
Berman, L. E.; Hastings, J. B.; Oversluizen, T. & Woodle, M.
Object Type:
Article
System:
The UNT Digital Library
Application of optical fluctuation diagnostics to transport studies in high temperature tokamak plasmas
First data was obtained from the TFTR BES system in May 1990, after the prototype 4-channel system with photomultiplier detectors from PBX-M was transferred to the TFTR Hot Cell. The system was expanded to 16 spatial channels during the Summer 1990 run period, and data of interest was obtained near the end of the run in October 1990. The most attention has been given to a radial profile data set obtained for an L-mode plasma condition in TFTR, where we characterized the nature of the long-wavelength turbulence seen by the BES diagnostic. We summarize here highlights of the initial run with BES or TFTR. We also give a progress report on support activities at UW.
Date:
January 1, 1991
Creator:
Fonck, R.J.
Object Type:
Report
System:
The UNT Digital Library
The bioenergetics of salt tolerance
The aim of this project was to try to understand the adaptive mechanisms that organisms develop in order to respond to a sudden transformation in their environment to a salt shock.'' To study this problem we used a fresh water oxygenic photosynthetic cyanobacterium known as Synecoccus 6311. This organism suffers injury after this sudden exposure to high concentrations of sodium chloride equivalent to or even higher than that in sea water. Yet they are able to re-establish their photosynthetic activity which is partially injured and return to virtually normal growth rates. Identification of the temporal sequence of changes involved in adaptation to this stress was the rationale. Indeed this project employed a wide variety of biochemical and biophysical methods, including electron spin resonance techniques and nuclear magnetic resonance to study the bioenergetics and transport mechanisms, growth and energy changes in these organisms and how the structural components of the cells changed in response to adaptation to growth at high salinity. The problem has relevance for higher plants because most of the arable farmland in the work is already under use and that which is not used is usually in salite environments. Hence, understanding basic mechanisms of salt tolerance is a …
Date:
January 1, 1991
Creator:
Packer, L.
Object Type:
Report
System:
The UNT Digital Library
Radiation induced micrencephaly in guinea pigs
A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between …
Date:
January 1, 1991
Creator:
Wagner, L.K.; Johnston, D.A. & Felleman, D.J.
Object Type:
Report
System:
The UNT Digital Library
Fractional processes and nuclear disassembly in very-heavy-ion collisions in the Fermi energy regime
Exclusive measurements of charged products and neutrons were performed for the reactions {sup 197}Au + (29 MeV/u) {sup 208}Pb and {sup 209}Bi + (28.2 MeV/u) {sup 136}Xe. The multiplicities of neutrons and charged particles are found to indicate collision impact parameters with different sensitivities. Characteristic correlations observed between massive products and light particles suggest the dominance of the damped-reaction mechanism in the Fermi energy domain. For central collisions, massive fragments are no longer observed, and a considerable fraction of the mass of the system is found disassembled into light particles and clusters. 75 refs., 19 figs.
Date:
January 1, 1991
Creator:
Schroeder, W.U.
Object Type:
Article
System:
The UNT Digital Library
Vibration considerations in the design of the Advanced Photon Source at Argonne National Laboratory
The Advanced Photon Source (APS), a new synchrotron radiation facility being built at Argonne National Laboratory, will provide the world's most brilliant X-ray beams for research in a wide range of technical fields. Successful operation of the APS requires an extremely stable positron closed orbit. Vibration of the storage ring quadrupole magnets, even in the submicron range, can lead to distortion of the positron closed orbit and to potentially unacceptable beam emittance growth, which results in degraded performance. This paper presents an overview of the technical approach used to minimize vibration response, beginning at the conceptual stage, through design and construction, and on to successful operation. Acceptance criteria relating to maximum allowable quadrupole magnet vibration are discussed. Soil properties are used to determine resonant frequencies of foundations and to predict attenuation characteristics. Two sources are considered to have the potential to excite the foundation: far-field sources, which are produced external to the facility, and near-field sources, which are produced within the facility. Measurements of ambient ground motion, monitored to determine far- field excitation, are presented. Ambient vibration was measured at several operating facilities within Argonne to gain insight on typical near-field excitation sources. Discussion covers the dynamic response characteristics of …
Date:
January 1, 1991
Creator:
Jendrzejczyk, J.A. & Wambsganss, M.W.
Object Type:
Article
System:
The UNT Digital Library
Aging Aircraft NDI Development and Demonstration Center (AANC): An overview
A major center with emphasis on validation of nondestructive inspection techniques for aging aircraft, the Aging Aircraft NDI Development and Demonstration Center (AANC), has been funded by the FAA at Sandia National Laboratories. The Center has been assigned specific tasks in developing techniques for the nondestructive inspection of static engine parts, assessing inspection reliability (POD experiments), developing test beds for nondestructive inspection validation, maintaining a FAA library of characterized aircraft structural test specimens, and leasing a hangar to house a high flight cycle transport aircraft for use as a full scale test bed. 3 refs.
Date:
January 1, 1991
Creator:
Walter, P. L.
Object Type:
Article
System:
The UNT Digital Library
Dependence of secondary ion emission from organic material on the energy loss of the impacting heavy ion
Samples of the amino acid valine were irradiated by 2.5 MeV-Ar, 0.8 MeV-Kr and 1.0 MeV Xe beams from the Argonne Dynamitron accelerator in order to study the energy distributions of ejected secondary ions. For Kr and Xe the nuclear stopping power exceeded the electronic stopping power by a factor 2 or 3, respectively, but the functional shape of the energy distributions and the mean ejection energies (0.9--1.4 eV) indicated that the molecular ions (M{plus minus}H){sup {plus minus}} are desorbed by an electronic sputter process. Contributions of atomic collision cascades were observed for the H{sup {minus}} ion. In the second part of the article, the overall dependence of molecular ion yields on the electronic energy loss is discussed in the framework of recent desorption models and the structure of the nuclear track.
Date:
January 1, 1991
Creator:
Hunt, J.E. (Argonne National Lab., IL (United States)) & Wien, K. (Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik)
Object Type:
Article
System:
The UNT Digital Library