Effects of longitudinal space charge in beams for heavy-ion fusion (open access)

Effects of longitudinal space charge in beams for heavy-ion fusion

A new analytic model is presented that accurately estimates the radially averaged axial component of the space-charge field of an axisymmetric heavy-ion beam in a cylindrical beam pipe. The model recovers details of the field near the beam ends that are overlooked by simpler models, and the results compare well to exact solutions of Poisson`s equation. Field values are shown for several simple beam profiles and are compared with values obtained from simpler models. The model has been implemented in the fluid/envelope code CIRCE and used to study longitudinal confinement in beams with a variety of axial profiles. The effects of errors in the longitudinal-control fields are presented.
Date: December 27, 1995
Creator: Sharp, W. M.; Friedman, A. & Grote, D. P.
Object Type: Article
System: The UNT Digital Library
Nuclear magnetic resonance: Its role as a microscopic probe of the electronic and magnetic properties of High-{Tc} superconductors and related materials (open access)

Nuclear magnetic resonance: Its role as a microscopic probe of the electronic and magnetic properties of High-{Tc} superconductors and related materials

NMR experiments are reported for Sr{sub 2}CuO{sub 2}Cl{sub 2}, HgBa{sub 2}CuO{sub 4+d}, YNi{sub 2}B{sub 2}C and YBa{sub 2}Cu{sub 3}O{sub 7}. NMR studies typify three different aspects of microscopic properties of HTSC. In non-superconducting antiferromagnetic (AF) prototype Sr{sub 2}CuO{sub 2}Cl{sub 2}, we used NMR to investigate Cu{sup 2+} correlated spin dynamics and AF phase transition in CuO2 layers. In the superconductors, we used NMR both to investigate the electronic properties of the Fermi-liquid in normal and superconducting states and to investigate flux lattice and flux-line dynamics in the superconducting state in presence of magnetic field. A summary of each study is given: {sup 35}Cl NMR was measured in Sr{sub 2}CuO{sub 2}Cl{sub 2} single crystals with T{sub N}=257K. {sub 35}Cl NMR relaxation rates showed crossover of Cu{sup 2+} spin dynamics from Heisenberg to XY-like correlation at 290 K well above T{sub N}. A field-dependent T{sub N} for H{perpendicular}c was observed and explained by a field-induced Ising-like anisotropy in ab plane. {sup 199}Hg NMR was measured in HgBa{sub 2}CuO{sub 4+d}. Properties of the Fermi-liquid are characterized by a single-spin fluid picture and opening of a spin pseudo-gap at q=0 above {Tc}. Below {Tc}, spin component of Knight shift decreases rapidly in agreement with …
Date: December 27, 1995
Creator: Suh, Byoung Jin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Progress report on the evaluation of porous cathode for the electrochemical reduction of nitrates and nitrites in liquid wastes (open access)

Progress report on the evaluation of porous cathode for the electrochemical reduction of nitrates and nitrites in liquid wastes

This report describes the experimental and modeling work performed to evaluate porous cathodes for the electrochemical reduction of nitrites in liquid wastes. The experiments were done using the MP{dagger} cell with two different porous cathodes: nickel foam and TySAR{trademark}SB{double_dagger}. The experimental results are compared with each other and to those obtained with a planar nickel cathode. The results show that the ammonia production reaction is the dominant cathodic reaction ({approximately}80% efficiency) for all three electrodes. The temperature range used in this study was 29-37 {circ}C while the catholyte feed was either 0.6M NaNO{sub 2} or 1.9M NaNO{sub 3}, both supported by a 1.33 M NaOH solution. All experiments used a constant current density of 0.25 A/cm{sup 2}. The experimental results suggest that the porous nickel electrode at lower temperatures ({approximately}31{circ}C) is the most efficient of the three electrodes for the reduction of nitrates and nitrites. The porous nickel electrode exhibited the highest conversion of nitrates and nitrites, and the lowest overpotential for a given current density. The partial current fractions at known catholyte concentrations were used to extract the exchange-current densities for the five cathodic reactions. Using these kinetic parameters, dynamic simulations of the four hour experiments were performed. Agreement …
Date: December 27, 1995
Creator: Hobbs, D. T.; Jha, K.; Weidner, J. W. & White, R. E.
Object Type: Report
System: The UNT Digital Library
APS Tcl/Tk library and interpreter extensions (open access)

APS Tcl/Tk library and interpreter extensions

This document serves as a User`s Manual and Reference for the library of Tcl and Tk procedures produced by the Operations Analysis Group. Also covered are compiled interpreter extensions.
Date: November 27, 1995
Creator: Saunders, C. & Borland, M.
Object Type: Report
System: The UNT Digital Library
Diverse topics in crystalline beams (open access)

Diverse topics in crystalline beams

Equations of motion are presented, appropriate to interacting charged particles of diverse charge and mass, subject to the external forces produced by various kinds of magnetic fields and radio-frequency (rf) electric fields in storage rings. These equations are employed in the molecular dynamics simulations to study the properties of crystalline beams. The two necessary conditions for the formation and maintenance of crystalline beams are summarized. The transition from ID to 2D, and from 2D to 3D is explored, and the scaling behavior of the heating rates is discussed especially in the high temperature limit. The effectiveness of various cooling techniques in achieving crystalline states has been investigated. Crystalline beams made of two different species of ions via sympathetic cooling are presented, as well as circulating ``crystal balls`` bunched in all directions by magnetic focusing and rf field. By numerically reconstructing the original experimental conditions of the NAP-M ring, it is found that only at extremely low beam intensities, outside of the range of the original measurement, proton particles can form occasionally-passing disks. The proposed New ASTRID ring is shown to be suitable for the formation and maintenance of crystalline beams of all dimensions.
Date: November 27, 1995
Creator: Wei, Jie; Draeseke, A.; Sessler, A. M. & Li, Xiao-Ping
Object Type: Article
System: The UNT Digital Library
Engineering development of advanced coal-fired low-emission boiler systems. Technical progress report No. 12, July--September 1995 (open access)

Engineering development of advanced coal-fired low-emission boiler systems. Technical progress report No. 12, July--September 1995

The overall objective of the Project is the expedited commercialization of advanced coal-fired low-emission boiler systems. The goals for emissions and plant efficiency are: NO{sub x} emissions not greater than 0.1 lb/million Btu; SO{sub x} emissions not greater than 0.1 lb/million Btu; particulate emissions not greater than 0.01 lb/million Btu; and net plant efficiency (HHV basis) not less than 42%. Other goals include: improved ash disposability and reduced waste generation; and reduced air toxics emissions. The final deliverables are a design data base that will allow future coal-fired power plants to meet the stated objectives, and a preliminary design of a Commercial Generation Unit. The work in Phase I covered a 24- month period and included system analysis, RD&T Plan formulation, component definition, and preliminary Commercial Generating Unit (CGU) design. Phase II will cover a 15-month period and will include preliminary Proof-of-Concept Test Facility (POCTF) design and subsystem testing. Phase III will cover a 9-month period and will produce a revised CGU design and a revised POCTF design, cost estimate and a test plan. Phase IV, the final Phase, will cover a 36- month period and will include POCTF detailed design, construction, testing, and evaluation.
Date: November 27, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The central peak revisited (open access)

The central peak revisited

The central peak in SrTiO{sub 3} was first observed by Riste and his collaborators in 1971. This was one of the key discoveries leading to an understanding of the dynamics of phase transitions. The most recent discovery of two length scales in SrTiO{sub 3} motivated a reinvestigation of the soft phonon and associated central peak by neutron scattering. These recent experiments shed new light on the nature of the central peak. It is now well established to be strongly sample dependent and it originates from defects in bulk crystals.
Date: October 27, 1995
Creator: Shirane, G.
Object Type: Article
System: The UNT Digital Library
Gamma Ray Burst Optical Counterpart Search Experiment (GROCSE) (open access)

Gamma Ray Burst Optical Counterpart Search Experiment (GROCSE)

GROCSE (Gamma-Ray Optical Counterpart Search Experiments) is a system of automated telescopes that search for simultaneous optical activity associated with gamma ray bursts in response to real-time burst notifications provided by the BATSE/BACODINE network. The first generation system, GROCSE 1, is sensitive down to Mv {approximately} 8.5 and requires an average of 12 seconds to obtain the first images of the gamma ray burst error box defined by the BACODINE trigger. The collaboration is now constructing a second generation system which has a 4 second slewing time and can reach Mv {approximately} 14 with a 5 second exposure. GROCSE 2 consists of 4 cameras on a single mount. Each camera views the night sky through a commercial Canon lens (f/1.8, focal length 200 mm) and utilizes a 2K x 2K Loral CCD. Light weight and low noise custom readout electronics were designed and fabricated for these CCDs. The total field of view of the 4 cameras is 17.6 x 17.6 {degree}. GROCSE II will be operated by the end of 1995. In this paper, the authors present an overview of the GROCSE system and the results of measurements with a GROCSE 2 prototype unit.
Date: October 27, 1995
Creator: Park, Hye-Sook; Ables, Elden; Bionta, Richard M.; Ott, Linda; Parker, Eric; Akerlof, Carl et al.
Object Type: Article
System: The UNT Digital Library
Guidelines for management of noxious weeds at Hanford (open access)

Guidelines for management of noxious weeds at Hanford

Integrated Pest Management Services is responsible for management and control of noxious weeds on the Hanford Site. Weed species and populations are prioritized and objective defined, according to potential site and regional impact. Population controls are implemented according to priority. An integrated approach is planned for noxious weed control in which several management options are considered and implemented separately or in coordination to best meet management objectives. Noxious weeds are inventories and monitored to provide information for planning and program review.
Date: October 27, 1995
Creator: Roos, R. C. & Malady, M. B.
Object Type: Report
System: The UNT Digital Library
Interdisciplinary study of reservoir compartments and heterogeneity. Quarterly technical progress report, July 1995--September 1995 (open access)

Interdisciplinary study of reservoir compartments and heterogeneity. Quarterly technical progress report, July 1995--September 1995

This United States Department of Energy (DOE) research project was established to document the integrated team approach for solving reservoir engineering problems. A field study integrating the disciplines of geology, geophysics, and petroleum engineering will be the mechanism for documenting the integrated approach. This is an area of keen interest to the oil and gas industry. The goal will be to provide tools and approaches that can be used to detect reservoir compartments, reach a better reserve estimate, and improve profits early in the life of a field.
Date: October 27, 1995
Creator: Kirk, C.W. Van & Thompson, R.S.
Object Type: Report
System: The UNT Digital Library
A progress report on the Large Block Test (open access)

A progress report on the Large Block Test

None
Date: October 27, 1995
Creator: Lin, W.; Wilder, D. & Blink, J.
Object Type: Report
System: The UNT Digital Library
Relative humidity in the near-field environment (open access)

Relative humidity in the near-field environment

The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada, for its suitability as a potential repository for high-level nuclear wastes. United States federal regulation 10CFR60 requires that radioactive nuclides be substantially contained in waste packages for 300 to 1000 years after the emplacement. To meet the regulation, a waste package container should remain intact for several hundreds of years. It has been shown that high humidity increases the corrosion potential of metallic container materials. Relative humidity as a function of water saturation in intact rock is measured. The results of this test can be used to calibrate the relative humidity in the near-field environment predicted by model calculations using thermal-hydrological codes such as VTOUGH. This is a report on the progress of that experiment.
Date: October 27, 1995
Creator: Lin, W.; Roberts, J. & Ruddle, D
Object Type: Article
System: The UNT Digital Library
Results from GROCSE I: A real-time search for gamma ray burst optical counterparts (open access)

Results from GROCSE I: A real-time search for gamma ray burst optical counterparts

The GROCSE I experiment (Gamma-Ray Optical Counterpart Search Experiment) is a rapid slewing wide field of view optical telescope at Lawrence Livermore National Laboratory which responds to triggers from the BATSE GRB data telemetry stream that have been processed and distributed by the BACODINE network. GROCSE 1 has been in continuous automated operation since January 1994. As of October 1995, sky images for 22 GRB triggers have been recorded, in some cases while the burst was still emitting gamma rays. The preliminary analysis of eight of these events are presented here. No optical counterparts have yet been detected. Limits for optical emission are given.
Date: October 27, 1995
Creator: Lee, B.; Akerlof, C. & Ables, E.
Object Type: Article
System: The UNT Digital Library
Tank 241-BY-106 rotary core sampling and analysis plan (open access)

Tank 241-BY-106 rotary core sampling and analysis plan

This sampling and analysis plan will identify characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples and one rotary mode core sample from tank 241-BY-106.
Date: October 27, 1995
Creator: Bell, Kevin E.
Object Type: Report
System: The UNT Digital Library
U.S. Bureau of Mines, phase I Hanford low-level waste melter tests: Melter offgas report (open access)

U.S. Bureau of Mines, phase I Hanford low-level waste melter tests: Melter offgas report

A multiphase program was initiated in 1994 to test commercially available melter technologies for the vitrification of the low-level waste (LLW) stream from defense wastes stored in underground tanks at the Hanford Site in southeastern Washington State. Phase 1 of the melter demonstration tests using simulated LLW was completed during fiscal year 1995. This document is the melter offgas report on testing performed by the U.S. Department of the Interior, Bureau of Mines, Albany Research Center in Albany, Oregon. The Bureau of Mines (one of the seven vendors selected) was chosen to demonstrate carbon electrode melter technology (also called carbon arc or electric arc) under WHC subcontract number MMI-SVV-384216. The document contains the complete offgas report for the first 24-hour melter test (WHC-1) as prepared by Entropy Inc. A summary of this report is also contained in the``U.S. Bureau of Mines, Phase 1 Hanford Low-Level Waste Melter Tests: Final Report`` (WHC-SD-WM-VI-030).
Date: October 27, 1995
Creator: Eaton, W.C.
Object Type: Report
System: The UNT Digital Library
Winters fuels report (open access)

Winters fuels report

The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter`s pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration`s (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter`s, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price …
Date: October 27, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
X-ray radiography of fracture flow and matrix imbibition (open access)

X-ray radiography of fracture flow and matrix imbibition

Knowledge of how water flows through unsaturated, fractured rock is critical for understanding and predicting the performance of a high- level nuclear waste repository. For instance, during gravity driven fracture flow, the distance that water can travel through a fracture network might be controlled by (1) the amount of water available, (2) the fracture aperture, (3) the capillary properties of the matrix, and (4) the saturation of the matrix. We have experimentally investigated fracture flow and fracture-matrix interactions using x- ray radiography to image some of the above factors and processes.
Date: October 27, 1995
Creator: Roberts, J. J. & Lin, Wunan
Object Type: Article
System: The UNT Digital Library
183 KE Potable water system analysis plan (open access)

183 KE Potable water system analysis plan

Sampling analysis plans (SAP) are a recognized manner of providing applicable requirements for conducting media sampling and analysis in a manner consistent with prescirbed objectives. This SAP has been prepared to satisfy the data quality objectives listed in this SAP with respect to the operation of the 183 KE potable water for K Area.
Date: September 27, 1995
Creator: Hunacek, G.S.
Object Type: Report
System: The UNT Digital Library
ARESE (ARM Enhanced Shortwave Experiment) Science Plan [Atmospheric Radiation Program] (open access)

ARESE (ARM Enhanced Shortwave Experiment) Science Plan [Atmospheric Radiation Program]

Several recent studies have indicated that cloudy atmospheres may absorb significantly more solar radiation than currently predicted by models. The magnitude of this excess atmospheric absorption, is about 50% more than currently predicted and would have major impact on our understanding of atmospheric heating. Incorporation of this excess heating into existing general circulation models also appears to ameliorate some significant shortcomings of these models, most notably a tendency to overpredict the amount of radiant energy going into the oceans and to underpredict the tropopause temperature. However, some earlier studies do not show this excess absorption and an underlying physical mechanism that would give rise to such absorption has yet to be defined. Given the importance of this issue, the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program is sponsoring the ARM Enhanced Shortwave Experiment (ARESE) to study the absorption of solar radiation by clear and cloudy atmospheres. The experimental results will be compared with model calculations. Measurements will be conducted using three aircraft platforms (ARM-UAV Egrett, NASA ER-2, and an instrumented Twin Otter), as well as satellites and the ARM central and extended facilities in North Central Oklahoma. The project will occur over a four week period beginning in …
Date: September 27, 1995
Creator: Valero, F. P. J.; Schwartz, S. E.; Cess, R. D.; Ramanathan, V.; Collins, W. D.; Minnis, P. et al.
Object Type: Report
System: The UNT Digital Library
The contact-temperature ignition (CTI) criteria for propagating chemical reactions including the effect of moisture and application to Hanford waste (open access)

The contact-temperature ignition (CTI) criteria for propagating chemical reactions including the effect of moisture and application to Hanford waste

To assure the continued absence of uncontrolled condensed-phase chemical reactions in connection with the Hanford waste materials, efforts have been underway including both theoretical and experimental investigations to clarify the requirements for such reactions. This document defines the differences and requirements for homogeneous runaway and propagating chemical reactions incuding a discussion of general contact-temperature ignition (CTI) condition for propagating reactions that include the effect of moisture. The CTI condition implies that the contact temperature or interface temperature between reacted and unreacted materials must exceed the ignition temperature and is compared to experimental data including both synthetic ferrocyanide and surrogate organic materials. In all cases, the occurrences of ignition accompanied by self-propagating reactions are consistent with the theoretical anticipations of the CTI condition.
Date: September 27, 1995
Creator: Cash, R.J.
Object Type: Report
System: The UNT Digital Library
Design development and testing of 60-watt capsules (open access)

Design development and testing of 60-watt capsules

To satisfy the safety requirements of a terrestrial 60-watt radioisotope heat source, it was necessary to determine whether the internal pressure buildup from the helium generated from Pu-238 decay would pose problems in a fire environment. Nine strength members (capsules), three of the end-cap weld design and six of the girth weld design, were pressure-burst tested. The end-cap weld design was not successful, with failure times of less than three minutes. The girth weld design gave favorable results, with life times ranging from 8 to 240 hours. All of the girth weld capsules failed in the center of the weld. The Oak Ridge National Laboratory stress rupture model equation for determining test life does not predict the test hours to failure for the girth weld design.
Date: September 27, 1995
Creator: Ruhkamp, J.D.
Object Type: Report
System: The UNT Digital Library
Double-Shell Tank Retrieval Allowable Heel Trade Analysis (open access)

Double-Shell Tank Retrieval Allowable Heel Trade Analysis

This Double-Shell Tank Retrieval Allowable Heel Trade Analysis evaluates the effects a remaining heel has on subsequent waste storage requirements after initial retrieval. The information contained in this analysis will be used as a basis to identify crucial double-shell tank (DST) retrieval system design and performance requirements for continued storage of waste in DSTs. The information presented in this analysis is summarized by the DST initial retrieval and reuse strategy. The strategy is based on the waste compatibility and consolidation requirements that are governed by the remaining heel after initial retrieval
Date: September 27, 1995
Creator: Grams, W. H.
Object Type: Report
System: The UNT Digital Library
Economic benefits of midseason reordering in apparel retailing (open access)

Economic benefits of midseason reordering in apparel retailing

This report presents a method for determining the value of reordering, explores factors that affect its value, and provides an estimate of the value under a range of conditions. The method is based on a stochastic process model of the demands the retailer faces. It uses a dynamic programming model to determine the optimal quantities to order and the expected profits. The analysis shows that the benefits of reordering are quite sensitive to the uncertainties in the demand and to the assumptions about the markdown of unsold merchandise at the end of the season.
Date: September 27, 1995
Creator: Lamont, A. & Elayat, H.
Object Type: Report
System: The UNT Digital Library
Effect of long-term thermal aging on the fracture toughness of austenitic stainless steel base and weld metals (open access)

Effect of long-term thermal aging on the fracture toughness of austenitic stainless steel base and weld metals

Compact tension specimens taken from FFTF primary piping materials (Type 316 stainless steel (SS) and 16-8-2 SS weld metal) and from reactor vessel materials (304 SS and 308 SS weld metal) were heated in laboratory furnaces from 100,000 hours. Fracture toughness testing was performed on these specimens, which are 7.62- and 25.4-mm thick, respectively at the aging temperature (482 and 427 degrees). Results were analyzed with the multiple-specimen method. Thermal aging continues to reduce the fracture toughness of FFTF component materials. Results show that thermal aging has a strong effect on the toughness degradation of weld metals, particularly for 16-8-2 SS weld whose aged/unaged Jc ratio is only 0.31 after 100,000-hour aging. The fracture toughness of the 308 and 16-8-2 SS weld metals fluctuated during 20,000 to 50,000-hour aging but deteriorated as the aging time increased to 100,000 hours; the toughness degradation is significant. Fracture control based on a fracture mechanics approach should be considered
Date: September 27, 1995
Creator: Huang, F.F.
Object Type: Report
System: The UNT Digital Library