25-ps neutron detector for measuring ICF-target burn history (open access)

25-ps neutron detector for measuring ICF-target burn history

We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25 ps FWHM. A thin piece of scintillator material acts as a neutron-to-light converter. A zoom lens images scintillator light to a high-speed (15 ps) optical streak camera for recording. A retractable nose cone positions the scintillator between 1 and 50 cm from a target. A simultaneously recorded optical fiducial pulse allows the streak camera time base to be calibrated relative to the incident laser power. Burn histories have been measured for deuterium-tritium filled targets with yields ranging between 10{sup 8} and 2 {times} 10{sup 13} neutrons.
Date: May 2, 1994
Creator: Lerche, R. A.; Phillion, D. W. & Tietbohl, G. L.
Object Type: Article
System: The UNT Digital Library
An analysis of the tritium content in fish from Upper Three Runs Creek (open access)

An analysis of the tritium content in fish from Upper Three Runs Creek

In November of 1988 the F/H-area effluent treatment facility (ETF) began releasing treated waste water to Upper Three Runs Creek. Previous to that time, there has been minimal discharge of plant waste water to this tributary of the Savannah River. The ETF is designed to remove the toxic and radioactive waste materials from the effluent stream and to meet the discharge limits of the South Carolina Department of Health and Environmental Control (SCDHEC). The only radioactive nuclide not removed by the process is tritium. Tritium, an isotope of hydrogen, is chemically associated with the water molecules in the waste stream and can not be economically removed at this time. The objective of this study was to determine the relationship between the concentration of tritium in the stream water and the concentration of tritium in the fish. Fish collections were made at two locations. The most upstream location was 50 meters downstream from the SRS Road C bridge. This is immediately downstream of the effluent discharge pipe from the ETF. The other location was at the bridge of SRS Road A (SC Highway 125). The water is removed from the fish by freeze drying under vacuum. This study suggests that, on …
Date: May 2, 1991
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
An analysis of the tritium content in fish from Upper Three Runs Creek (open access)

An analysis of the tritium content in fish from Upper Three Runs Creek

In November of 1988 the F/H-area effluent treatment facility (ETF) began releasing treated waste water to Upper Three Runs Creek. Previous to that time, there has been minimal discharge of plant waste water to this tributary of the Savannah River. The ETF is designed to remove the toxic and radioactive waste materials from the effluent stream and to meet the discharge limits of the South Carolina Department of Health and Environmental Control (SCDHEC). The only radioactive nuclide not removed by the process is tritium. Tritium, an isotope of hydrogen, is chemically associated with the water molecules in the waste stream and can not be economically removed at this time. The objective of this study was to determine the relationship between the concentration of tritium in the stream water and the concentration of tritium in the fish. Fish collections were made at two locations. The most upstream location was 50 meters downstream from the SRS Road C bridge. This is immediately downstream of the effluent discharge pipe from the ETF. The other location was at the bridge of SRS Road A (SC Highway 125). The water is removed from the fish by freeze drying under vacuum. This study suggests that, on …
Date: May 2, 1991
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
Application of alternating current impedance to fuel cell modeling (open access)

Application of alternating current impedance to fuel cell modeling

AC impedance has provided a useful diagnostic tool in the Los Alamos polymer electrolyte fuel cell (PEFC) program. The author reviews the techniques he has used in ac impedance modeling. These techniques include equation implementation, model simplification and verification, least squares fitting, application of two-dimensional Laplace equation solvers handling complex interfacial boundary conditions, and interpretation of impedance features. The separate features of the complete electrode model are explained by analytic examples.
Date: May 2, 1999
Creator: Springer, Thomas E.
Object Type: Article
System: The UNT Digital Library
Automatically processed alpha-track radon monitor (open access)

Automatically processed alpha-track radon monitor

An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.
Date: May 2, 1991
Creator: Langner, G. H. Jr.
Object Type: Patent
System: The UNT Digital Library
Characterization of transuranium actinide alloy phase diagrams (open access)

Characterization of transuranium actinide alloy phase diagrams

Alloys of Np have been studied less than those,of the neighboring elements, U and Pu; the higher actinides have received even less attention. Recent interest in {sup 237}Np, {sup 241}Am and other actinide isotopes as significant, long-lived and highly radiotoxic nuclear waste components, and particularly the roles of metallic materials new handling/separations and remediation technologies, demands that this paucity of information concerning alloy behaviors be addressed. An additional interest in these arises from the possibility of revealing fundamental properties and bonding interactions, which would further characterize the unique electronic structures (e.g., 5f electrons) of the actinide elements. The small empirical knowledge basis presently available for understanding and modeling the alloying behavior of Np is summarized here, with emphasis on our recent results for the Np-Am, Np-Zr and Np-Fe phase diag rams. In view of the limited experimental data base for neptunium and the transplutonium metals, the value of semi-empirical intermetallic bonding models for predicting actinide alloy thermodynamics is evaluated.
Date: May 2, 1994
Creator: Gibson, J. K.; Haire, R. G.; Gensini, M. M. & Ogawa, T.
Object Type: Article
System: The UNT Digital Library
Cold vacuum drying facility 90% design review (open access)

Cold vacuum drying facility 90% design review

This document contains review comment records for the CVDF 90% design review. Spent fuels retrieved from the K Basins will be dried at the CVDF. It has also been recommended that the Multi-Conister Overpacks be welded, inspected, and repaired at the CVD Facility before transport to dry storage.
Date: May 2, 1997
Creator: O`Neill, C.T.
Object Type: Report
System: The UNT Digital Library
Conceptual design report for tank farm restoration and safe operations, project W-314 (open access)

Conceptual design report for tank farm restoration and safe operations, project W-314

This Conceptual Design Report (CDR) presents the conceptual level design approach that satisfies the established technical requirements for Project W-314, `Tank Farm Restoration and Safe Operations.` The CDR also addresses the initial cost and schedule baselines for performing the proposed Tank Farm infrastructure upgrades. The scope of this project includes capital improvements to Hanford`s existing tank farm facilities(primarily focused on Double- Shell Tank Farms) in the areas of instrumentation/control, tank ventilation, waste transfer, and electrical systems.
Date: May 2, 1996
Creator: Briggs, S.R., Westinghouse Hanford
Object Type: Report
System: The UNT Digital Library
A cross section measurement of charm hyperons {Xi}{sub c}{sup +} and {Xi}{sub c}{sup 0} in 250 GeV p/K/{pi}-nucleon interactions (open access)

A cross section measurement of charm hyperons {Xi}{sub c}{sup +} and {Xi}{sub c}{sup 0} in 250 GeV p/K/{pi}-nucleon interactions

Fermilab Experiment 769 used a charge-selected, hadron beam of mean energy 250 GeV/c, composed of pions, kaons, and protons, impinging on beryllium, aluminum, copper and tungsten targets. Using a sample of approximately 4000 {Xi}{sub s}{sup {minus}} {yields} {Lambda}{sup 0}{pi}{sup {minus}} decays, measurements of the charm baryon forward cross sections times branching ratio {pi}{sup {+-}}N {yields} {Xi}{sub c}{sup +}X and {pi}{sup {+-}}N {yields} {Xi}{sub c}{sup 0}X are presented. Upper limits on {alpha} x BR are also determined for the states {Xi}{sub c}{sup +} {yields} {Xi}{sub s}{sup {minus}}{pi}{sup +}{pi}{sup +} and {Xi}{sub c}{sup 0} {yields} {Xi}{sub s}{sup {minus}}{pi}{sup +} produced in (p, {pi}{sup +}, {pi}{sup {minus}}, K{sup +}, K{sup {minus}})-nucleon interactions.
Date: May 2, 1995
Creator: Francisco, J. & Vergara, A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Damage measurements on optical materials for use in high-peak-power lasers (open access)

Damage measurements on optical materials for use in high-peak-power lasers

Recently, we have expanded our efforts to develop state-of-the-art optical components for use in large-scale, high-peak-power, solid state lasers. Laser-induced damage to many of these components sets critical constraints on construction costs and limits the peak powers attainable in current and proposed devices. Increasing the damage threshold whenever possible by improving materials fabrication technology is therefore the ultimate goal of our work. Our research has resulted in an extensive database of laser-damage measurements. We present summaries of these measurements with particular emphasis on those taken at 1064 nm and 355 nm.
Date: May 2, 1990
Creator: Rainer, F.; Brusasco, R. M.; Campbell, J. H.; DeMarco, F. P.; Gonzales, R. P.; Kozlowski, M. R. et al.
Object Type: Article
System: The UNT Digital Library
Decant pump assembly and controls qualification testing - test report (open access)

Decant pump assembly and controls qualification testing - test report

This report summarizes the results of the qualification testing of the supernate decant pump and controls system to be used for in-tank sludge washing in aging waste tank AZ-101. The test was successful and all components are qualified for installation and use in the tank.
Date: May 2, 1996
Creator: Staehr, T.W., Westinghouse Hanford
Object Type: Report
System: The UNT Digital Library
Development of an experimental database and theories for prediction of thermodynamic properties of aqueous electrolytes and nonelectrolytes of geochemical significance at supercritical temperatures and pressures (open access)

Development of an experimental database and theories for prediction of thermodynamic properties of aqueous electrolytes and nonelectrolytes of geochemical significance at supercritical temperatures and pressures

Volumetric measurements have been completed for CH{sub 4}, CO{sub 2}, and H{sub 2}S at temperatures from 25{degrees}C to 380{degrees}C and 2 or 3 pressures at each temperature. The H{sub 2}S and CO{sub 2} solutions are stored in aluminized mylar bags in PVC pipes with water surrounding the bags at a pressure of several atmospheres. The methane is stored in a one liter autoclave with a sliding teflon piston engaging the sides of the autoclave which separates the standard methane solution from the pressurizing fluid. The solutions are prepared at 100 to 200 atmospheres and do not need to be re-standardized after each experiment. We also have some measurements on aqueous ammonia, boric acid, and acetic acid. Preliminary calculations of the free energy of methane in water at room temperature as a function of the model parameters for the methane have been finished. In preparation for these calculations, the theory and practice of the free energy perturbation calculations was reviewed. In molecular dynamics and Monte Carlo calculations a system does not immediately equilibrate to a change in the Hamiltonian, so that there is a time lag or a configuration number lag in the response of the system. These lags cause errors …
Date: May 2, 1991
Creator: Wood, R.H.
Object Type: Report
System: The UNT Digital Library
Direct conversion of radioactive and chemical waste containing metals, ceramics, amorphous solids, and organics to glass (open access)

Direct conversion of radioactive and chemical waste containing metals, ceramics, amorphous solids, and organics to glass

The Glass Material Oxidation and Dissolution System (CMODS) is a new process for direct conversion of radioactive, mixed, and chemical wastes to glass. The wastes can be in the chemical forms of metals, ceramics, amorphous solids, and organics. GMODS destroys organics and it incorporates heavy metals and radionuclides into a glass. Processable wastes may include miscellaneous spent fuels (SF), SF hulls and hardware, plutonium wastes in different forms, high-efficiency particulate air (HEPA) filters, ion-exchange resins, failed equipment, and laboratory wastes. Thermodynamic calculations indicate theoretical feasibility. Small-scale laboratory experiments (< 100 g per test) have demonstrated chemical laboratory feasibility for several metals. Additional work is needed to demonstrate engineering feasibility.
Date: May 2, 1994
Creator: Forsberg, C. W.; Beahm, E. C. & Parker, G. W.
Object Type: Article
System: The UNT Digital Library
Direct Simulation of Ion Beam Induced Stressing and Amorphization of Silicon (open access)

Direct Simulation of Ion Beam Induced Stressing and Amorphization of Silicon

Using molecular dynamics (MD) simulation, the authors investigate the mechanical response of silicon to high dose ion-irradiation. The authors employ a realistic model to directly simulate ion beam induced amorphization. Structural properties of the amorphized sample are compared with experimental data and results of other simulation studies. The authors find the behavior of the irradiated material is related to the rate at which it can relax. Depending upon the ability to deform, the authors observe either the generation of a high compressive stress and subsequent expansion of the material, or generation of tensile stress and densification. The authors note that statistical material properties, such as radial distribution functions are not sufficient to differentiate between the different densities of the amorphous samples. For any reasonable deformation rate, the authors observe an expansion of the target upon amorphization in agreement with experimental observations. This is in contrast to simulations of quenching which usually result in a denser structure relative to crystalline Si. The authors conclude that although there is substantial agreement between experimental measurements and simulation results, the amorphous structures being investigated may have fundamental differences; the difference in density can be attributed to local defects within the amorphous network. Finally the …
Date: May 2, 1999
Creator: Beardmore, K.M. & Gronbech-Jensen, N.
Object Type: Article
System: The UNT Digital Library
Emittance growth from rotated quadrupoles in heavy ion accelerators (open access)

Emittance growth from rotated quadrupoles in heavy ion accelerators

We derive a set of moment equations which incorporates linear quadrupolar focusing and space-charge defocusing, in the presence of rotational misalignments of the quadrupoles about the direction of beam propagation. Although the usual beam emittance measured relative to fixed transverse x and y coordinate axes is not constant, a conserved emittance-like quantity has been found. Implications for alignment tolerances in accelerators for heavy-ion inertial fusion are discussed.
Date: May 2, 1995
Creator: Barnard, J.J.
Object Type: Article
System: The UNT Digital Library
Ethanol Production from Glucose and Xylose by Immobilized <i>Zymomonas mobilis</i> CP4(pZB5) (open access)

Ethanol Production from Glucose and Xylose by Immobilized <i>Zymomonas mobilis</i> CP4(pZB5)

Fermentation of glucose-xylose mixtures to ethanol was investigated in batch and continuous experiments using immobilized recombinant <i>Zymomonas mobilis</i> CP4(pZB5). This microorganism was immobilized by entrapment in k-carrageenan beads having a diameter of 1.5-2.5 mm. Batch experiments showed that the immobilized cells co-fermented glucose and xylose to ethanol and that the presence of glucose improved the xylose utilization rate. Batch fermentation of rice straw hydrolyzate containing 76 g/L glucose and 33.8 g/L xylose gave an ethanol concentration of 44.3 g/L after 24 hours, corresponding to a yeild of 0.46 g ethanol/g sugars. Comparable results were achieved with a synthetic sugar control. Continuous fermentation runs were performed in a laboratory scale fluidized-bed bioreactor (FBR). Glucose-xylose feed mixtures were run through the FBR at residence times of 2 to 4 hours. Glucose conversion to ethanol was maintained above 98% in all continuous runs. Xylose conversion to ethanol was highest at 91.5% for a feed containing 50 g/L glucose-13 g/L xylose at a dilution rate of 0.24 h<sup>-1</sup>. The xylose conversion to ethanol decreased with increasing feed xylose concentration, dilution rate and age of the immobilized cells. Volumetric ethanol productivities in the range of 6.5 to 15.3 g/L-h were obtained.
Date: May 2, 1999
Creator: Blanco, M.; Davison, B. H.; Krishnan, M. S.; Nghiem, N. P. & Shattuck, C. K.
Object Type: Article
System: The UNT Digital Library
Forces in a Thin Cosine (nTheta) Helical Wiggler (open access)

Forces in a Thin Cosine (nTheta) Helical Wiggler

We wish to calculate the Lorentz body force associated with pure multipole helical magnetic fields (i.e, proportional to cos(n{theta})) whose strength varies purely as a Fourier sinusoidal series of the longitudinal coordinate z (say proportional to cos(2m-1){pi}z)/L, where L denotes the half-period of the wiggler field and m= 1,2,3... We also wish to apply such forces to the current sheet, and solve for the stress distribution required to maintain such a coil in equilibrium. In the calculations of Lorentz forces we include the self field contribution as well as possible contributions arising from additional nested helical windings. We shall demonstrate that in cases where the current is situated on a surface of discontinuity at r=R (i.e. J=f({theta},z)) and the Lorentz body force is integrated on that surface, a closed form solution for the stress distribution can be obtained and such a solution includes contributions from possible nested multi pole magnets. Finally we demonstrate that in the limiting 2D case where the field strength does not vary with z ( period 2L tends to infinity) the stress reduces to known 2D expressions.
Date: May 2, 1997
Creator: Caspi, S.
Object Type: Report
System: The UNT Digital Library
Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Technical progress report, January 1, 1995--March 31, 1995 (open access)

Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Technical progress report, January 1, 1995--March 31, 1995

The objective of this project is to develop a comprehensive, interdisciplinary, and quantitative characterization of a fluvial-deltaic reservoir which will allow realistic inter-well and reservoir-scale modeling to be developed for improved oil-field development in similar reservoirs world-wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a three-dimensional representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for inter-well to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduction of economic risks, increased recovery from existing oil fields, and more reliable reserve calculations. Transfer of the project results to the petroleum industry is an integral component of the project.
Date: May 2, 1995
Creator: Allison, M. L.
Object Type: Report
System: The UNT Digital Library
High precision Woelter optic calibration facility (open access)

High precision Woelter optic calibration facility

We have developed an off-line facility for very precise characterization of the reflectance and spatial resolution of the grazing incidence Woelter Type 1 x-ray optics used at Nova. The primary component of the facility is a high brightness, ``point`` x-ray source consisting of a focussed DC electron beam incident onto a precision manipulated target/pinhole array. The data are recorded with a selection of detectors. For imaging measurements we use direct exposure x-ray film modules or an x-ray CCD camera. For energy-resolved reflectance measurements, we use lithium drifted silicon detectors and a proportional counter. An in situ laser alignment system allows precise location and rapid periodic alignment verification of the x-ray point source, the statically mounted Woelter optic, and the chosen detector.
Date: May 2, 1994
Creator: Morales, R. I.; Remington, B. A. & Schwinn, T.
Object Type: Article
System: The UNT Digital Library
Investigation of mineral transformations and ash deposition during staged combustion. Quarterly technical progress report, January 1, 1994--March 31, 1994 (open access)

Investigation of mineral transformations and ash deposition during staged combustion. Quarterly technical progress report, January 1, 1994--March 31, 1994

Progress during the second quarter of a three-year study was made in two areas: Coal selection and characterization, combustor modifications and preliminary testing. Potential sources for coal have been identified and an attempt will be made to use the same coals as a similar doe study. Advances have continued in our SEM-based analytical techniques. Modifications to an existing reactor system have been initiated. A new coal feeder has been installed and tested. Finally, specific tasks for the next quarter have been identified and reported.
Date: May 2, 1994
Creator: Harb, J. N.
Object Type: Report
System: The UNT Digital Library
ISO-PC Version 1.98: User`s guide (open access)

ISO-PC Version 1.98: User`s guide

This document describes how to use Version 1.98 of the shielding program named ISO-PC. Version 1.98 corrects all known errors in ISOSHLD-II. In addition, a few numeric problems have been eliminated. There are three new namelist variables, 25 additional shielding materials, and 5 more energy groups. The two major differences with the original ISOSHLD-II are the removal of RIBD(radioisotope buildup and decay) source generator, and the removal of the non-uniform source distribution parameter, SSV1. This version of ISO-PC works with photon energies from 10 KeV to 10 MeV using 30 energy groups.
Date: May 2, 1995
Creator: Rittmann, P. D.
Object Type: Report
System: The UNT Digital Library
A lower bound for the QRQW PRAM (open access)

A lower bound for the QRQW PRAM

The queue-read, queue-write (QRQW) parallel random access machine (PRAM) model is a shared memory model which allows concurrent reading and writing with a time cost proportional to the contention. This is designed to model currently available parallel machines more accurately than either the CRCW PRAM or EREW PRAM models. Many algorithmic results have been developed for the QRQW PRAM. However, the only lower bound results have been fairly simple reductions from lower bounds for other models, such as the EREW PRAM or the ``few-write`` CREW PRAM. Here we present a lower bound specific to the QRQW PRAM. This lower bound is on the problem of Linear Approximate Compaction (LAC), whose input consists of at most m marked items in an array of size n, and whose output consists of the rn marked items in an array of size 0(m). There is an O({radical}log n), expected time randomized algorithm for LAC on the QRQW PRAM. We prove a lower bound of {Omega}(log log log n) expected time for any randomized algorithm for LAC. This bound applies regardless of the number of processors and memory cells of the QRQW PRAM. The previous best lower bound was {Omega}(log* n) time, taken from the …
Date: May 2, 1995
Creator: MacKenzie, P. D.
Object Type: Article
System: The UNT Digital Library
Lower bounds for randomized Exclusive Write PRAMs (open access)

Lower bounds for randomized Exclusive Write PRAMs

In this paper we study the question: How useful is randomization in speeding up Exclusive Write PRAM computations? Our results give further evidence that randomization is of limited use in these types of computations. First we examine a compaction problem on both the CREW and EREW PRAM models, and we present randomized lower bounds which match the best deterministic lower bounds known. (For the CREW PRAM model, the lower bound is asymptotically optimal.) These are the first non-trivial randomized lower bounds known for the compaction problem on these models. We show that our lower bounds also apply to the problem of approximate compaction. Next we examine the problem of computing boolean functions on the CREW PRAM model, and we present a randomized lower bound, which improves on the previous best randomized lower bound for many boolean functions, including the OR function. (The previous lower bounds for these functions were asymptotically optimal, but we improve the constant multiplicative factor.) We also give an alternate proof for the randomized lower bound on PARITY, which was already optimal to within a constant additive factor. Lastly, we give a randomized lower bound for integer merging on an EREW PRAM which matches the best deterministic …
Date: May 2, 1995
Creator: MacKenzie, P.D.
Object Type: Article
System: The UNT Digital Library
Methods of Off-Gas Flammability Control for DWPF Melter Off-Gas System at Savannah River Site (open access)

Methods of Off-Gas Flammability Control for DWPF Melter Off-Gas System at Savannah River Site

Several key operating variables affecting off-gas flammability in a slurry-fed radioactive waste glass melter are discussed, and the methods used to prevent potential off-gas flammability are presented. Two models have played a central role in developing such methods. The first model attempts to describe the chemical events occurring during the calcining and melting steps using a multistage thermodynamic equilibrium approach, and it calculates the compositions of glass and calcine gases. Volatile feed components and calcine gases are fed to the second model which then predicts the process dynamics of the entire melter off-gas system including off-gas flammability under both steady state and various transient operating conditions. Results of recent simulation runs are also compared with available data
Date: May 2, 1996
Creator: Choi, A.S. & Iverson, D.C.
Object Type: Report
System: The UNT Digital Library