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Three Dimensional Laser Cooling of Stored and Circulating Ion Beams by Means of a Coupling Cavity (open access)

Three Dimensional Laser Cooling of Stored and Circulating Ion Beams by Means of a Coupling Cavity

It is shown, theoretically, that a coupling cavity; namely an rf cavity operating in the TM{sup 210} mode, when inserted in a storage ring will enhance the coupling between longitudinal and transverse degrees of freedom. As a result, it is shown that the demonstrated very effective laser cooling of the longitudinal motion, can now be extended to transverse motion; i.e., employed to cool a beam in all three directions.
Date: February 1, 1994
Creator: Okamoto, H.; Sessler, Andrew M. & Mohl, D.
System: The UNT Digital Library
Vision Denton '94 (open access)

Vision Denton '94

Clippings from the Denton Record-Chronicle titled 'Vision Denton '94, City builds on education reputation'. The two clippings are part of the same story covering the collaboration of colleges including UNT, museums, and DFW Metroplex area schools. The collaboration offers better art programs and college credit to high schoolers.
Date: February 12, 1994
Creator: Cobler, Paula
System: The UNT Digital Library
Waste minimization at Lawrence Livermore National Laboratory: A case study of environmentally conscious manufacturing (open access)

Waste minimization at Lawrence Livermore National Laboratory: A case study of environmentally conscious manufacturing

The purpose of this paper is to provide an update on what we`ve accomplished and have planned in our plating operation at Lawrence Livermore National Laboratory (LLNL) in the area of waste minimization. Our efforts have included issues other than waste minimization and, therefore, fall under the wider umbrella entitled pollution prevention or environmentally conscious electroplating. Approximately one year has passed since our last report on pollution prevention and since this topic remains a high-effort activity much more has been accomplished. Our efforts to date fall under the first two generation categories of waste reduction. Good housekeeping practices, inventory control, and minor changes in operating practices (first generation) resulted in an impressive amount of waste reduction. In the second generation of waste reduction, current technology, separation technologies, and material substitutions were used to reduce emission and wastes. The third generation of improvements requires significant technological advances in process synthesis and engineering. We are presently starting some projects in this third generation phase and these will be discussed at the end of this paper.
Date: February 1, 1994
Creator: Steffani, C. P. & Dini, J. W.
System: The UNT Digital Library
Near-extinction and final burnout in coal combustion (open access)

Near-extinction and final burnout in coal combustion

The late stages of char combustion have a special technological significance, as carbon conversions of 99% or greater are typically required for the economic operation of pulverized coal fired boilers. In the present article, two independent optical techniques are used to investigate near-extinction and final burnout phenomenas. Captive particle image sequences, combined with in situ optical measurements on entrained particles, provide dramatic illustration of the asymptotic nature of the char burnout process. Single particle combustion to complete burnout is seen to comprise two distinct stages: (1) a rapid high-temperature combustion stage, consuming about 70% of the char carbon and ending with near-extinction of the heterogeneous reactions due to a loss of global particle reactivity, and (2) a final burnout stage occurring slowly at lower temperatures. For particles containing mineral matter, the second stage can be further subdivided into: (2a) late char combustion, which begins after the near-extinction event, and converts carbon-rich particles to mixed particle types at a lower temperature and a slower rate; and (2b) decarburization of ash -- the removal of residual carbon inclusions from inorganic (ash) frameworks in the very late stages of combustion. This latter process can be extremely slow, requiring over an order of magnitude …
Date: February 1, 1994
Creator: Hurt, R. H. & Davis, K. A.
System: The UNT Digital Library
Automated fiber pigtailing technology (open access)

Automated fiber pigtailing technology

The high cost of optoelectronic (OE) devices is due mainly to the labor-intensive packaging process. Manually pigtailing such devices as single-mode laser diodes and modulators is very time consuming with poor quality control. The Photonics Program and the Engineering Research Division at LLNL are addressing several issues associated with automatically packaging OE devices. A furry automated system must include high-precision fiber alignment, fiber attachment techniques, in-situ quality control, and parts handling and feeding. This paper will present on-going work at LLNL in the areas of automated fiber alignment and fiber attachment. For the fiber alignment, we are building an automated fiber pigtailing machine (AFPM) which combines computer vision and object recognition algorithms with active feedback to perform sub-micron alignments of single-mode fibers to modulators and laser diodes. We expect to perform sub-micron alignments in less than five minutes with this technology. For fiber attachment, we are building various geometries of silicon microbenches which include on-board heaters to solder metal-coated fibers and other components in place; these designs are completely compatible with an automated process of OE packaging. We have manually attached a laser diode, a thermistor, and a thermo-electric heater to one of our microbenches in less than 15 minutes …
Date: February 1, 1994
Creator: Strand, O. T.; Lowry, M. E.; Lu, S. Y.; Nelson, D. C.; Nikkel, D. J.; Pocha, M. D. et al.
System: The UNT Digital Library
Ten new checks to assess the statistical quality of Monte Carlo solutions in MCNP (open access)

Ten new checks to assess the statistical quality of Monte Carlo solutions in MCNP

The central limit theorem can be applied to a Monte Carlo solution if: The random variable x has a finite mean and a finite variance; and the number N of independent observations grows large. When these two conditions are satisfied, a confidence interval based on the normal distribution with a specified coverage probability can be formed. The first requirement is generally satisfied by the knowledge of the type of Monte Carlo tally being used. The Monte Carlo practitioner has only a limited number of marginally quantifiable methods to assess the fulfillment of the second requirement. Ten new statistical checks have been created and added to MCNP4A to assist with this assessment. The checks examine the mean, relative error, figure of merit, and two new quantities: The relative variance of the variance; the empirical history score probability density function f(x). The two new quantities are described. For the first time, the underlying f(x) for Monte Carlo tallies is calculated for routine inspection and automated analysis. The ten statistical checks are defined, followed by the results from a statistical study on analytic Monte Carlo and other realistic f(x)s to validate their values and uses in MCNP. Passing all 10 checks is a …
Date: February 1, 1994
Creator: Forster, R. A.; Booth, T. E. & Pederson, S. P.
System: The UNT Digital Library
Distributions of 14 elements into 10 liquid extractants from simulated acid-dissolved sludge and acidified supernate solutions of Hanford high-level waste (open access)

Distributions of 14 elements into 10 liquid extractants from simulated acid-dissolved sludge and acidified supernate solutions of Hanford high-level waste

The distributions of 14 elements into ten extractants were measured from simulant solutions that represent acidic dissolved sludge and acidified supernate from Hanford HLW Tank 102-SY. The extractants: LIX{sup TM}-26, LIX{sup TM}-54, LIX{sup TM}-84, LIX{sup TM}-1010, Cyanex{sup TM} 272, Cyanex{sup TM} 923, Aliquat{sup TM} 336, DHDECMP, DHDECMP-DIPB, and CMPO-DIPB, were sorbed on porous carbon beads to provide dry-appearing beads that would be suitable for column operations. The selected elements, which represent fission products: Ce, Cs, Sr, Tc, and Y; actinides: U, Pu, and Am; and matrix elements: Cr, Co, Fe, Mn, Zn, and Zr; were traced by radionuclides and measured by gamma spectrometry. Distribution coefficients for each of 280 element/absorber/solution combinations were measured for dynamic contact periods of 30 minutes, 2 hours, and 6 hours to provide sorption kinetics information for the selected elements from these complex media. The resulting 840 measured distribution coefficients are presented.
Date: February 1, 1994
Creator: Marsh, S. F.; Svitra, Z. V. & Bowen, S. M.
System: The UNT Digital Library
Changes in Organic Sulfur Compounds in Coal Macerals During Liquefaction (open access)

Changes in Organic Sulfur Compounds in Coal Macerals During Liquefaction

Several general trends were observed in reactivity patterns of sulfur compounds in macerals. Sulfur is reduced in the asphaltene fraction compared to initial maceral. Aliphatics are removed and polycyclic aromatic compounds are both stable and probably formed under these conditions. Molecules containing two sulfur atoms are formed. The preasphaltenes are now being analyzed by DEIHRMS.
Date: February 1, 1994
Creator: Winans, R. E.; Joseph, J. T. & Fisher, R. B.
System: The UNT Digital Library
Technology features of a network technology for safeguards applications (open access)

Technology features of a network technology for safeguards applications

This report describes a new flexible technology which is now available to design sensor and control networks based on a protocol embedded in an intelligent communications processor. The flexibility allows a system designer and/or a technical installer to make appropriate tradeoffs among simplicity, functionality, and cost in the design of network nodes and their installation. This is especially important in designing an installation scenario for the safeguards network. The network technology permits several choices of installations with the same basic node hardware. A pre-installed network offers maximum simplicity and no flexibility since it will operate as programmed during manufacture or the pre-installation setup and checkout. At the other end of the spectrum, a network can be installed using network management software and a computer. The combination of the network management software and computer hardware is generally referred to as a Network Management Tool (NMT). The NMT option offers full flexibility to change the network during or after installation. Different NMT can provide different degrees of complexity depending upon the applications and the amount of changes that need to be made during installation.
Date: February 1, 1994
Creator: Johnson, C. S.
System: The UNT Digital Library
Unique passive diagnostic for slapper detonators (open access)

Unique passive diagnostic for slapper detonators

The objective of this study was to find a material and configuration that could reliably detect the proper functioning of a current slapper detonator. Because of the small size of the slapper geometry (on the order of a 15 mils), most diagnostic techniques are not suitable. This program has the additional requirement that the device could not use any electrical power or output signals. This required that the diagnostic be completely passive. The paper describes the three facets of the development effort: complete characterization of the slapper using VISAR measurements, selection of the diagnostic material and configuration, and testing of the prototype designs. The VISAR testing required the use of a special optical probe to allow the laser light to reach both bridges of the slapper detonator. Results are given in the form of flyer velocity as a function of the initiating voltage level. The selected diagnostic design functions in a manner similar to a dent block except that the impact of the Kapton disk causes a fracture pattern. A quick visual inspection is all that is needed to determine if the flyer velocity exceeded the threshold value. Sub-threshold velocities produce a substantially different appearance.
Date: February 1, 1994
Creator: Brigham, W. P. & Schwartz, J. J.
System: The UNT Digital Library
The TORSED and TORSET codes for coupling three-dimensional TORT calculations (open access)

The TORSED and TORSET codes for coupling three-dimensional TORT calculations

Two new codes perform ``bootstrapping`` of either two- or three-dimensional boundary fluxes to a TORT three-dimensional calculation. TORSED couples a DORT RZ calculation to an XYZ TORT. Two methods of directional remapping are available, each less expensive than methods previously available for this work. TORSED is compatible with the discontinuous mesh features of TORT. The second code, TORSET, couples two XYZ TORT problems. The second problem may lie entirely inside the first, or it may touch over only a portion of its surface. TORSET can obtain most of its input data from the primary TORT problem or from an automatic mesh generator. Both codes are available for general use on Cray mainframes and UNIX workstations.
Date: February 1, 1994
Creator: Rhoades, W. A.
System: The UNT Digital Library
Approach for systematic evaluation of transuranic waste management alternatives (open access)

Approach for systematic evaluation of transuranic waste management alternatives

This paper describes an approach for systematic evaluation of management alternatives that are being considered for the treatment, storage, and disposal of transuranic waste (TRUW) at U.S. Department of Energy sites. The approach, which is currently under development, would apply WASTE-MGMT, a database application model developed at Argonne National Laboratory, to estimate projected environmental releases and would evaluate impact measures such as health risk and costs associated with each of the waste management alternatives. The customized application would combine site-specific TRUW inventory and characterization data with treatment and transportation parameters to estimate the quantities and characteristics of the wastes to be treated, emissions of hazardous substances from the treatment facilities, and the quantities and characteristics of the wastes to be shipped between sites. These data would then be used to estimate for several TRUW management scenarios the costs and health risks of constructing and operating the required treatment facilities and of transporting TRUW for treatment and final disposal. Treatment, storage, and disposal of TRUW at DOE sites is composed of many variables and options at each stage. The approach described in this paper would provide for efficient consideration of all of these facets when evaluating potentially feasible TRUW management alternatives. …
Date: February 1, 1994
Creator: Hong, K.; Koebnick, B. & Kotek, T.
System: The UNT Digital Library
A brief introduction to symplectic integrators and recent results (open access)

A brief introduction to symplectic integrators and recent results

The author begins with a brief synopsis about Hamiltonian systems and symplectic maps. A symplectic integrator is a symplectic map {phi}(q,p;t) that systematically approximates the time t flow of a Hamiltonian system. Systematic means: (1) in time step, t, i.e. the error should vanish as some power of the time step, and (2) in order of approximation, i.e. one would like a hierarchy of such {phi} that have errors that vanish as successively higher powers of the time step. At present the authors known two general types of symplectic integrators: (1) implicit integrators that are derived from a generating function or from algebraic conditions on Runge-Kutta schemes, and (2) explicit integrators that are derived from integrable Hamiltonians or from algebraic conditions on Runge-Kutta schemes.
Date: February 1, 1994
Creator: Channell, P. J.
System: The UNT Digital Library
Prospects for studies of ground-state proton decays with the Holifield Radioactive Ion Beam Facility (open access)

Prospects for studies of ground-state proton decays with the Holifield Radioactive Ion Beam Facility

By using radioactive ions from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory it should be possible to identify many new ground-state proton emitters in the mass region from Sn to Pb. During this production and search process the limits of stability on the proton-rich side of the nuclidic chart will be delineated for a significant fraction of medium-weight elements and our understanding of the proton-emission process will be expanded and improved.
Date: February 1, 1994
Creator: Toth, K. S.
System: The UNT Digital Library
Criticality safety aspects of decontamination and decommissioning at defense nuclear facilities (open access)

Criticality safety aspects of decontamination and decommissioning at defense nuclear facilities

Defense nuclear facilities have operated for forty years with a well-defined mission to produce weapons components for the nation. With the end of the cold war, the facilities` missions have changed to one of decontamination and decommissioning. Off-normal operations and use of new procedures, such as will exist during these activities, have often been among the causal factors in previous criticality accidents at process facilities. This paper explores the similarities in causal factors in previous criticality accidents to the conditions existing in current defense nuclear facilities undergoing the transition to decontamination and decommissioning. Practices to reduce the risk to workers, the public, and the environment are recommended.
Date: February 1, 1994
Creator: Croucher, D. W.
System: The UNT Digital Library
Femtosecond transient dichroism/birefringence studies of solute- solvent friction and solvent dynamics (open access)

Femtosecond transient dichroism/birefringence studies of solute- solvent friction and solvent dynamics

Ultrafast, heterodyne, polarization spectroscopies are used to measure solute-solvent frictional coupling and characterize the neat solvent`s relaxation dynamics on femtosecond and picosecond timescales.
Date: February 1, 1994
Creator: Chang, Y. J.; Castner, E. W. Jr.; Konitsky, W. & Waldeck, D. H.
System: The UNT Digital Library
Dual-band infrared imaging for concrete bridge deck inspection (open access)

Dual-band infrared imaging for concrete bridge deck inspection

Dual-band infrared (DBIR) imaging methods and unique image-correction algorithms used successfully for underground and obscured object imaging and detection (of buried mines, archaeological structures, geothermal aquifers and airframe defects) are adapted for inspection of concrete highways and bridge decks to provide early warnings of subsurface defects. To this end, we prepared small concrete test slabs with defects (embedded plastic layers). We used selective DBIR (3--5 {mu}m and 8--12 {mu}m) image ratios to depict the defect sites and remove the effects of surface clutter. We distinguish true temperature-difference signals (at surrogate delamination sites) from emissivity noise (at sites with oil stains, sand, gravel, metal parts and roughness differences) towards improved concrete bridge deck inspections.
Date: February 1, 1994
Creator: Durbin, P. & Del Grande, N.
System: The UNT Digital Library
The Rocky Flats Plant Waste Stream and Residue Identification and Characterization Program (WSRIC): Progress and achievements (open access)

The Rocky Flats Plant Waste Stream and Residue Identification and Characterization Program (WSRIC): Progress and achievements

The Waste Stream and Residue Identification and Characterization (WSRIC) Program, as described in the WSRIC Program Description delineates the process knowledge used to identify and characterize currently-generated waste from approximately 5404 waste streams originating from 576 processes in 288 buildings at Rocky Flats Plant (RFP). Annual updates to the WSRIC documents are required by the Federal Facilities Compliance Agreement between the US Department of Energy, the Colorado Department of Health and the Environmental Protection Agency. Accurate determination and characterization of waste is a crucial component in RFP`s waste management strategy to assure compliance with Resource Conservation and Recovery Act (RCRA) storage and treatment requirements, as well as disposal acceptance criteria. The WSRIC Program was rebaselined in September 1992, and serves as the linchpin for documenting process knowledge in RFP`s RCRA operating record. Enhancements to the WSRIC include strengthening the waste characterization rationale, expanding WSRIC training for waste generators, and incorporating analytical information into the WSRIC building books. These enhancements will improve credibility with the regulators and increase waste generators` understanding of the basis for credible waste characterizations.
Date: February 1, 1994
Creator: Ideker, V. L. & Doyle, G. M.
System: The UNT Digital Library
Semiconductor microcavity lasers (open access)

Semiconductor microcavity lasers

New kinds of semiconductor microcavity lasers are being created by modern semiconductor technologies like molecular beam epitaxy and electron beam lithography. These new microcavities exploit 3-dimensional architectures possible with epitaxial layering and surface patterning. The physical properties of these microcavities are intimately related to the geometry imposed on the semiconductor materials. Among these microcavities are surface-emitting structures which have many useful properties for commercial purposes. This paper reviews the basic physics of these microstructured lasers.
Date: February 1, 1994
Creator: Gourley, P. L.; Wendt, J. R.; Vawter, G. A.; Warren, M. E.; Brennan, T. M. & Hammons, B. E.
System: The UNT Digital Library
Coupling correction using closed orbit measurements (open access)

Coupling correction using closed orbit measurements

The authors describe a coupling correction scheme they have developed and used to successfully reduce the vertical emittance of the NSLS X-Ray ring by a factor of 6 to below 2 A. This gives a vertical to horizontal emittance ratio of less than 0.2%. They find the strengths of 17 skew quadrupoles to simultaneously minimize the vertical dispersion and the coupling. As a measure of coupling they utilize the shift in vertical closed orbit resulting from a change in strength of a horizontal steering magnet. Experimental measurements confirm the reduced emittance.
Date: February 18, 1994
Creator: Safranek, J. & Krinsky, S.
System: The UNT Digital Library
Parallel processing Monte Carlo radiation transport codes (open access)

Parallel processing Monte Carlo radiation transport codes

Issues related to distributed-memory multiprocessing as applied to Monte Carlo radiation transport are discussed. Measurements of communication overhead are presented for the radiation transport code MCNP which employs the communication software package PVM, and average efficiency curves are provided for a homogeneous virtual machine.
Date: February 1, 1994
Creator: McKinney, G. W.
System: The UNT Digital Library
Advances in and uses of gamma-ray field instrumentation at Los Alamos (open access)

Advances in and uses of gamma-ray field instrumentation at Los Alamos

We are developing a set of tools to be used by the Safeguards Assay Group to solve problems found in safeguards and the domestic nuclear industry. The tools are also applicable to problems dealing with the environment, defense, and other areas of national and international interest. We have used extensively the advances in hardware and software since our last multichannel analyzer (MCA) development activities over a decade ago. We are also using our experience with and feedback from users of our previous instruments. In analyzing the instrument needs of our constituents and the characteristics of our previous instruments, which we think have inhibited their broader use, we have concluded that uses for an MCA-type instrument are widely varied and fundamentally changing,and that any new instruments should include a versatile, widely used hardware interface, which is as independent as possible of hardware standards, and which is readily interfaced to the computers or controllers rapidly evolving in the commercial sector. In addition, software tools must be provided that allow Los Alamos, users, and third parties to quickly and conveniently develop software specific to the user or the measurement to control the basic instrument we develop. This paper deals mainly with a miniature …
Date: February 1, 1994
Creator: Halbig, J. K.; Klosterbuer, S. F.; Russo, P. A.; Sprinkle, J. K. Jr.; Smith, S. E. & Ianakiev, K.
System: The UNT Digital Library
Managing performance of DB2 Ad Hoc Reports (open access)

Managing performance of DB2 Ad Hoc Reports

The DB2 financial reporting systems at Westinghouse Savannah River Company consists of 212 standardized reports that over 1034 users have accessed in 1993 to generate their reports. Each report has a range of selection criteria that the users can specify. Depending on the selection criteria, a report can access from a few rows to millions of rows of data. When this new DB2 system went into production in 1992, the CPU was at 100% utilization. From the beginning, ad hoc reports had a backlog of 4--5 days. Since DB2 was a new DBMS, most people blamed the poor report turn around times on DB2 as an inefficient DBMS and on a shortage of CPU cycles. Since we are unable to purchase a more powerful CPU, the only option left to us was to improve report turn around was system and application performance tuning. This document presents our efforts in these areas. Education of users in report submission was a starting point. And as to index tuning techniques that were applied, we created more friendly indexes, used clustering indexes, and used a reorganizing mechanism. A more efficient SQL was written which saved a lot of money.
Date: February 1, 1994
Creator: Chow, A.
System: The UNT Digital Library
In situ studies of zeolite syntheses using powder diffraction methods: Crystallization of ``instant zeolite A`` powder and CoAPO-5 (open access)

In situ studies of zeolite syntheses using powder diffraction methods: Crystallization of ``instant zeolite A`` powder and CoAPO-5

A series of hydrothermal zeolite synthesis were performed on a powder diffractometer using synchrotron radiation and a position sensitive detector. Direct observation of the induction period (nucleation stage), crystallization and transformation of zeolite 4A (Na-LTA) was possible due to the intense X-ray beam which allows fast data collection. High pressure experiments were performed, allowing observation of hydrothermal synthesis of a cobalt substituted AlPO{sub 4}-zeolite, CoAPO-5, up to 165{degrees}C. The temperature dependence of crystallization rates of CoAPO-5 was studied. This is to our knowledge the first time resolved powder diffraction studies of zeolite syntheses using angle dispersive synchrotron powder diffraction.
Date: February 1, 1994
Creator: Norby, P.; Christensen, A. N. & Hanson, J. C.
System: The UNT Digital Library