Non-inductive current drive scenarios for steady state operation of an ITER HARD option (open access)

Non-inductive current drive scenarios for steady state operation of an ITER HARD option

The requirements for steady state operation of a High Aspect Ratio Design (HARD) option for ITER using noninductive current driven by Neutral Beam (NB) injection, Lower Hybrid (LH) slow waves, and Fast Waves (FW) have been examined. For the higher field (B{sub T} = 7.1 T) and moderate density (<n{sub e}> = 1.1 {times} 10{sup 20} m{sup {minus}3}) in this HARD steady state operating point, NB injection provides the optimal current drive subject to the constraints of minimizing the total input power and achieving a high plasma internal inductance (1{sub i} = 0.75; i.e. a peaked current drive profile). An alternate scenario uses FW current drive in the plasma core combined with LH waves in the outer plasma regions in place of the neutral beams, with approximately 30% higher power requirement. Finally, Electron Cyclotron (EC) resonance current drive is used in either scenario to provide localized perturbation of the current profile at the q = 2 surface for disruption stabilization. 7 refs., 5 figs., 1 tab.
Date: September 25, 1991
Creator: Fenstermacher, M.; Nevins, W.; Bulmer, R.; Lindquist, W.; Parker, J.; Smith, G. (Lawrence Livermore National Lab., CA (United States)) et al.
System: The UNT Digital Library
Battery testing at Argonne National Laboratory (open access)

Battery testing at Argonne National Laboratory

Argonne National Laboratory's Analysis Diagnostic Laboratory (ADL) tests advanced batteries under simulated electric and hybrid vehicle operating conditions. The ADL facilities also include a post-test analysis laboratory to determine, in a protected atmosphere if needed, component compositional changes and failure mechanisms. The ADL provides a common basis for battery performance characterization and life evaluations with unbiased application of tests and analyses. The battery evaluations and post-test examinations help identify factors that limit system performance and life, and the most-promising R D approaches for overcoming these limitations. Since 1991, performance characterizations and/or life evaluations have been conducted on eight battery technologies (Na/S, Li/S, Zn/Br, Ni/MH, Ni/Zn, Ni/Cd, Ni/Fe, and lead-acid). These evaluations were performed for the Department of Energy's. Office of Transportation Technologies, Electric and Hybrid Propulsion Division (DOE/OTT/EHP), and Electric Power Research Institute (EPRI) Transportation Program. The results obtained are discussed.
Date: March 25, 1993
Creator: DeLuca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F. & Webster, C. E.
System: The UNT Digital Library
The effect of chemical composition on the PCT durability of mixed waste glasses from wastewater treatment sludges (open access)

The effect of chemical composition on the PCT durability of mixed waste glasses from wastewater treatment sludges

An experimental program has been designed to examine the chemical durability of glass compositions derived from the vitrification of simulated wastewater treatment sludges. These sludges represent the majority of low-level mixed wastes currently in need of treatment by the US DOE. The major oxides in these model glasses included SiO{sub 2}, Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Na{sub 2}O, CaO and Fe{sub 2}O{sub 3}. In addition, three minor oxides, BaO, NiO, and PbO, were added as hazardous metals. The major oxides were each varied at two levels resulting in 32 experimental glasses. The chemical durability was measured by the 7-Day Product Consistency Test (PCT). The normalized sodium release rates (NRR{sub Na}) of these glasses ranged from 0.01 to 4.99 g/m{sup 2}. The molar ratio of the glass-former to glass-modifier (F/M) was found to have the greatest effect on PCT durability. Glass-formers included SiO{sub 2}, Al{sub 2}O{sub 3}, and B{sub 2}O{sub 3}, while Na{sub 2}O, CaO, BaO, NiO, and PbO were glass-modifiers. As this ratio increased from 0.75 to 2.0, NRR{sub Na} was found to decrease between one and two orders of magnitude. Another important effect on NRR{sub Na} was the Na{sub 2}O/CaO ratio. As this ratio increased from 0.5 to …
Date: January 25, 1995
Creator: Resce, James L.; Ragsdale, R. Giles; Overcamp, Thomas J.; Bickford, Dennis F. & Cicero, Connie A.
System: The UNT Digital Library
Specimen Size Effect on the Creep of Si3N4 (open access)

Specimen Size Effect on the Creep of Si3N4

The effect of specimen size on the measured tensile creep behavior of a commercially available gas pressure sintered Si3N4 was examined. Button-head tensile test specimens were used for the testing, and were machined to a variety of different gage section diameters (ranging from 2.5 to 6.35 mm) or different surface-area-to-volume ratios. The specimens were then creep tested at 1350 Degrees C and 200 MPa with tensile creep strain continuously measured as a function of time. The steady-state creep rate increased and the lifetime decreased with an increase in diameter (or decrease in the ratio of gage section surface area to volume). The time and specimen size dependence of transformation of a secondary phase correlated with the observed creep rate and lifetime dependence.
Date: January 25, 1999
Creator: Barnes, A. S.; Ferber, M. K.; Kirkland, T. P. & Wereszczak, A. A.
System: The UNT Digital Library
Prediction of the Inert Strength Distribution of Si3N4 Diesel Valves (open access)

Prediction of the Inert Strength Distribution of Si3N4 Diesel Valves

Censored Weibull strength distributions were generated with NT551 silicon nitride four-point flexure data using the ASTM C1161-B and 5.0 mm diameter cylindrical specimens. Utilizing finite element models and AlliedSignal's life prediction codes, the inert or fast fracture strength failure probability of a ceramic diesel valve was estimated from these data sets. The failure probability prediction derived from each data set were found to be more conservative than valve strength data. Fractographic analysis of the test specimens and valves showed that the cylindrical specimens failed from a different flaw population than the prismatic flexure bars and the valves. The study emphasizes the prerequisite of having coincident flaw populations homogeneously distributed in both the test specimen and the ceramic component. Lastly, it suggests that unless material homogeneity exists, that any meaningful life prediction or reliability analysis of a component may not be possible.
Date: January 25, 1999
Creator: Andrews, M. J.; Breder, K. & Wereszczak, A. A.
System: The UNT Digital Library
Utilization of a hydraulic barrier to control migration of a uranium plume (open access)

Utilization of a hydraulic barrier to control migration of a uranium plume

A uranium plume emanating from the U.S. Department of Energy`s Fernald Environmental Management Project (FEMP) in Fernald, Ohio had migrated off site and the leading edge of the plume had already mixed with an organic and inorganic plume emanating from two industries south of the FEMP. A method was needed to prevent the further southern migration of the plume, minimize any impacts to the geometry, concentrations, distribution or flow patterns of the organic and inorganic plumes emanating from the off-site industries, while meeting the ultimate cleanup goals for the FEMP. This paper discusses the use of a hydraulic barrier created to meet these goals by pumping a five well recovery system and the problems associated with the disposition of over 2 million gallons per day of water with low concentrations of uranium.
Date: January 25, 1995
Creator: Brettschneider, D. J.; Simmons, R. A. Jr.; Kappa, J. D. & Stover, J. A.
System: The UNT Digital Library
Near earth object fuels (neo-fuels): Discovery, prospecting and use (open access)

Near earth object fuels (neo-fuels): Discovery, prospecting and use

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO`s is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today`s cost. A suggested resource verification plan is presented.
Date: August 25, 1992
Creator: Zuppero, A. C. & Jacox, M. G.
System: The UNT Digital Library
What controls phytoplankton production in nutrient-rich areas of the open sea? (open access)

What controls phytoplankton production in nutrient-rich areas of the open sea?

The oceans play a critical role in regulating the global carbon cycle. Deep-ocean waters are roughly 200% supersaturated with CO{sub 2} compared to surface waters, which are in contact with the atmosphere. This difference is due to the flux of photosynthetically derived organic material from surface to deep waters and its subsequent remineralization, i.e. the ``biological pump``. The pump is a complex phytoplankton-based ecosystem. the paradoxical nature of ocean regions containing high nutrients and low phytoplankton populations has intrigued biological oceanographers for many years. Hypotheses to explain the paradox include the regulation of productivity by light, temperature, zooplankton grazing, and trace metal limitation and/or toxicity. To date, none of the hypotheses, or combinations thereof, has emerged as a widely accepted explanation for why the nitrogen and phosphorus are not depleted in these regions of the oceans. Recently, new evidence has emerged which supports the hypothesis that iron limitation regulates primary production in these areas. This has stimulated discussions of the feasibility of fertilizing parts the Southern Ocean with iron, and thus sequestering additional atmospheric CO{sub 2} in the deep oceans, where it would remain over the next few centuries. The economic, social, and ethical concerns surrounding such a proposition, along …
Date: June 25, 1991
Creator: Weiler, C. S.
System: The UNT Digital Library
The Effect of Prior Out-of-Plane Damage on the in-Plane Behavior of Unreinforced Masonry Infilled Frames (open access)

The Effect of Prior Out-of-Plane Damage on the in-Plane Behavior of Unreinforced Masonry Infilled Frames

In order to address the effect of prior out-of-plane damage on the in-plane behavior of unreinforced masonry infills, two full-scale (24 feet tall by 28 feet long) structural clay tile infills and one frame-only (no infilling) were constructed and tested. The infilled frame, consisting of two wide flange columns surrounded by masonry plasters and an eccentric wide flange purlin, was identical to many of the infills located at the Oak Ridge Y-12 Plant. The masonry infill was approximately 12.5 inches thick and was composed of individual four- and eight-inch hollow clay tile (HCT) units. One of the infill panels was tested out-of-plane by four quasi-static actuators -- two on each column. The test structure was deflected out-of-plane equally at all four actuator locations in order to simulate the computed deflection path of the top and bottom chords of a roof truss framing into the columns at these locations. Prior to the infill testing, a bare frame was loaded similarly in order to determine the behavior and stiffness contribution of the frame only. Following the out-of-plane test of the infilled panel, the structure was loaded in-plane to failure in order to ascertain residual strength. A second, identical infilled frame was then …
Date: August 25, 1993
Creator: Henderson, R. C.; Jones, W. D.; Burdette, E. G. & Porter, M. L.
System: The UNT Digital Library
Pass or fail: A new test for password legitimacy (open access)

Pass or fail: A new test for password legitimacy

While other programs check for bad passwords after the fact, it in important to have good passwords at all times, not just after the latest Crack run. To this end we have modified Larry Wall`s Perl password program and added, among other features, the ability to check a sorted list of all the ``bad passwords`` that Crack will generate, given all the dictionaries that we could get our hands on (107 MB of unique words, so far). The combination of improvements has turned publicly available code into a powerful tool that can aid sites in the maintenance of local security.
Date: September 25, 1992
Creator: Cherry, A.; Henderson, M. W.; Nickless, W. K.; Olson, R. & Rackow, G.
System: The UNT Digital Library
Managing electronic records: A guideline (open access)

Managing electronic records: A guideline

A committee at Martin Marietta Energy Systems (MMES) has drafted a guideline to assist offices in the management of electronic records. This paper will address the activities surrounding its creating. The guideline is for use by creators, users, and custodians of any type of electronic information. The guideline supports and supplements requirements from DOE and the National Archives and Records Administration (NARA), other internal processes such as system reviews, and the comprehensive records management program. While an in-house publication, it could prove useful to other organizations implementing an electronic records management program.
Date: October 25, 1994
Creator: Stewart, J. G.
System: The UNT Digital Library
Equation of state of neutron star matter, limiting, rotational periods of fast pulsars, and the properties of strange stars (open access)

Equation of state of neutron star matter, limiting, rotational periods of fast pulsars, and the properties of strange stars

In this paper the following items will be treated: The present status of dense nuclear matter calculations and constraints on the behavior of the associated equation of state at high densities from data on rapidly rotating pulsars. Recent finding of the likely existence of a mixed phase of baryons and quarks forming a coulomb lattice in the dense cores of neutron stars. Review of important findings of recently performed calculations of rapidly rotating compact stars. These are constructed in the framework of general relativity theory for a representative collection of realistic nuclear equations of state. Establish the minimum-possible rotational periods of gravitationally bound neutron stars and self-bound strange stars. Its knowledge is of fundamental importance for the decision between pulsars that can be understood as rotating neutron stars and those that cannot (signature of hypothetical self-bound matter of which strange stars are the likely stellar candidates. Investigate the properties of sequences of strange stars. Specifically, we answer the question whether such objects can give rise to the observed phenomena of pulsar glitches, which is at the present time the only astrophysical test of the strange-quark-matter hypothesis.
Date: October 25, 1993
Creator: Weber, F. & Glendenning, N. K.
System: The UNT Digital Library
Hypersingular integrals at a corner (open access)

Hypersingular integrals at a corner

For a smooth boundary, hypersingular integrals can be defined as a limit from the interior, the approach direction being taken, for convenience, normal to the surface. At a boundary corner, the limit process, with a necessarily non-normal approach direction, provides a valid definition of the hypersingular equation, as long as the direction is employed for all integrations. The terms which are potentially singular in the limit are shown to cancel, provided the function approximations at the corner are consistent. The analytical formulas for the singular integrals are more complicated than for a smooth surface, but are easily obtained using symbolic computation. These techniques have been employed to accurately solve the ``L-shaped domain`` potential problem considered by Jaswon and Symm.
Date: March 25, 1993
Creator: Gray, L. J. & Manne, L. L.
System: The UNT Digital Library
Simulations of spectral broadening by cross-phase modulation (XPM) with chaotic light pulses (open access)

Simulations of spectral broadening by cross-phase modulation (XPM) with chaotic light pulses

Spectral broadening of single-frequency laser pulses by optical cross-phase modulation (XPM) with chaotic laser pulses in birefringent single-mode optical fibers is investigated numerically and results are compared with experiments. By this process we have generated laser pulses of variable bandwidth (1--25 {Angstrom}) at the fundamental wavelength (1053 nm) for amplification in high power solid-state Nd:glass lasers used for inertial confinement fusion research. Simulations indicate that a temporally smooth XPM pulse can be generated with intensity fluctuations of less than 10% and spectral width greater than 50 {Angstrom} using a short length ({approximately}5 m) of special low dispersion and low birefringence fiber, e.g. D = 10 ps/nm-km (normal dispersion) and {Delta}n = 2 {times} 10{sup {minus}5}. Readily available fibers of similar length, with parameters of D = 40 ps/nm-km and {Delta}n = 6 {times} 10{sup {minus}5}, can give spectral widths exceeding 25 {Angstrom}, but the noise will range from 25 to 60%. Broadband laser pulses generated by XPM are now routinely used at Lawrence Livermore National Laboratory for active smoothing of the laser irradiance on targets by the technique of smoothing-by-spectral dispersion.
Date: May 25, 1993
Creator: Henesian, M. A.; Dixit, S. N.; Chen, C. J.; Wai, P. K. A. & Menyuk, C. R.
System: The UNT Digital Library
Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys (open access)

Health and safety guide for inorganic compounds and metals used in the fabrication of superconductive alloys

This health and safety guide was written to satisfy two objectives: to summarize the toxicity of metals and alloys used in superconductivity for the benefit of those who work with these materials, and to summarize and describes the basic principles of a highly technical field from a health and safety point-of-view for the benefit of health professionals. The guide begins with a profile of the superconductivity industry, including a list of current and potential applications, a literature review of the market potential, and summary of the current industry status. The body of the paper provides a toxicity and hazard summary for 50 metals, alloys and metal oxides used in superconductivity. The toxicity and hazard summary for all 50 compounds includes: occupational exposure limits, explosiveness and flammability potential, LD{sub 50}'s, chemical and physical properties, incompatibilities and reactivities, recommended personal protective equipment, symptoms of acute and chronic exposure, target organs and toxic effects, and steps for emergency first aid. Finally, a discussion of general occupational hygiene principles is provided, with emphasis on how these principles apply to the unique field of superconductivity. 41 refs.
Date: April 25, 1990
Creator: Arnold, S. D. & Talley, G. M.
System: The UNT Digital Library
ICOOLl: A Simulation Code for Ionization Cooling of Muon Beams. (open access)

ICOOLl: A Simulation Code for Ionization Cooling of Muon Beams.

Current ideas [1,2] for designing a high luminosity muon collider require significant cooling of the phase space of the muon beams. The only known method that can cool the beams in a time comparable to the muon lifetime is ionization cooling [3,4]. This method requires directing the particles in the beam at a large angle through a low Z absorber material in a strong focusing magnetic channel and then restoring the longitudinal momentum with an rf cavity. We have developed a new 3-D tracking code ICOOL for examining possible configurations for muon cooling. A cooling system is described in terms of a series of longitudinal regions with associated material and field properties. The tracking takes place in a coordinate system that follows a reference orbit through the system. The code takes into account decays and interactions of {approx}50-500 MeV/c muons in matter. Material geometry regions include cylinders and wedges. A number of analytic models are provided for describing the field configurations. Simple diagnostics are built into the code, including calculation of emittances and correlations, longitudinal traces, histograms and scatter plots. A number of auxiliary files can be generated for post-processing analysis by the user.
Date: March 25, 1999
Creator: Fernow, R. C.
System: The UNT Digital Library
Scintillating-fiber imaging detector for 14-MeV neutrons (open access)

Scintillating-fiber imaging detector for 14-MeV neutrons

The authors have created a detector to image the neutrons emitted by imploded inertial-confinement fusion targets. The 14-MeV neutrons, which are produced by deuterium-tritium fusion events in the target, pass through an aperture to create an image on the detector. The neutron radiation is converted to blue light (430 nm) with a 20-cm-square array of plastic scintillating fibers. Each fiber is 10-cm long with a 1-mm-square cross section; approximately 35-thousand fibers make up the array. The resulting blue-light image is reduced and amplified by a sequence of fiber-optic tapers and image intensifiers, then acquired by a CCD camera. The fiber-optic readout system was tested optically for overall throughput the resolution. The authors plan to characterize the scintillator array reusing an ion-beam neutron source as well as DT-fusion neutrons emitted by inertial confinement targets. Characterization experiments will measure the light-production efficiency, spatial resolution, and neutron scattering within the detector. Several neutron images of laser-fusion targets have been obtained with the detector. Several neutron images of laser-fusion targets have been obtained with the detector. They describe the detector and their characterization methods, present characterization results, and give examples of the neutron images.
Date: July 25, 1994
Creator: Ress, D.; Lerche, R. A.; Ellis, R. J.; Heaton, G. W.; Nelson, M. B.; Mant, G. et al.
System: The UNT Digital Library
Status of the Relativistic Heavy Ion Collider (open access)

Status of the Relativistic Heavy Ion Collider

Accelerator Physics issues, such as the dynamical aperture, the beam lifetime and the current--intensity limitation are carefully studied for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The single layer superconducting magnets, of 8 cm coil inner diameter, satisfying the beam stability requirements have also been successfully tested. The proposal has generated wide spread interest in the particle and nuclear physics. 1 ref., 4 figs., 3 tabs.
Date: April 25, 1990
Creator: Lee, S. Y.
System: The UNT Digital Library
A Review of Methodologies for Determining the Age and History of Nuclear Materials of Interest in the Nuclear Safeguards, Arms Control, and Nonproliferation Regimes. (open access)

A Review of Methodologies for Determining the Age and History of Nuclear Materials of Interest in the Nuclear Safeguards, Arms Control, and Nonproliferation Regimes.

None
Date: July 25, 1999
Creator: Kane, W. R.; Kaplan, E.; Harbottle, G.; Katcoff, S. & Moorthy, A. R.
System: The UNT Digital Library
Near earth object fuels (neo-fuels): Discovery, prospecting and use (open access)

Near earth object fuels (neo-fuels): Discovery, prospecting and use

The 1992 discovery of a water-ice, near-Earth object (NEO) in the space near Earth is evaluated as a source of rocket fuel and life support materials for Earth orbit use. Nuclear thermal rockets using steam propellant are evaluated and suggested. The space geological formation containing such water-rich NEO's is described. An architecture couples near-Earth object fuels (neo-fuel) extraction with use in Earth orbits. Preliminary mass payback analyses show that space tanker systems fueled from space can return in excess of 100 times their launched mass from the NEO, per trip. Preliminary cost estimates indicate neo-fuel costs at Earth orbit can be 3 orders of magnitude below today's cost. A suggested resource verification plan is presented.
Date: August 25, 1992
Creator: Zuppero, A. C. & Jacox, M. G.
System: The UNT Digital Library
Germanium orthogonal strip detectors with amorphous-semiconductor contacts (open access)

Germanium orthogonal strip detectors with amorphous-semiconductor contacts

None
Date: October 25, 1999
Creator: Luke, P. N.; Amman, M.; Phlips, B. F.; Johnson, W. N. & Kroeger, R. A.
System: The UNT Digital Library
Experimental Time Resolved Electron Beam Temperature Measurements Using Bremsstrahlung Diagnostics (open access)

Experimental Time Resolved Electron Beam Temperature Measurements Using Bremsstrahlung Diagnostics

Electron beam temperature, {beta}{perpendicular} (= v{perpendicular}/v), is important to control for the development of high dose flash radiographic bremsstrahlung sources. At high voltage (&gt; 5 MV) increasing electron beam temperature has a serious deleterious effect on dose production. The average and time resolved behavior of beam temperature was measured during radiographic experiments on the HERMES III accelerator (10 MV, 50 kA, 70 ns). A linear array of thermoluminescent dosimeters (TLDs) were used to estimate the time integrated average of beam temperature. On and off-axis photoconducting diamond (PCD) detectors were used to measure the time resolved bremsstrahlung dose rate, which is dependent on beam energy and temperature. The beam temperature can be determined by correlating PCD response with accelerator voltage and current and also by analyzing the ratio of PCD amplitudes on and off axis. This ratio is insensitive to voltage and current and thus, is more reliable than utilizing absolute dose rate. The data is unfolded using comparisons with Monte Carlo simulations to obtain absolute beam temperatures. The data taken on HERMES III show abrupt increases in {beta}{perpendicular} midway through the pulse indicating rapid onset of beam instability.
Date: June 25, 1999
Creator: Menge, P. R.; Maenchen, J. E.; Mazarakis, M. G. & Rosenthal, S. E.
System: The UNT Digital Library
Design and development of the vacuum systems for the APT project ED & D cryomodule (open access)

Design and development of the vacuum systems for the APT project ED & D cryomodule

The mechanical design for both the insulating vacuum system and the cavity vacuum system of the APT ED and D Cryomodule is summarized. The pre-cooldown pressure limits for the insulating vacuum and the cavity vacuum are 10{sup {minus}5} Torr and 10{sup {minus}6} Torr, respectively. In addition, the cold cavity operating pressure limits are 10{sup {minus}6} Torr for the insulating system and 10{sup {minus}8} Torr for the cavity system. The designs of these systems utilize both turbomolecular pumps and the cold surfaces of the superconducting Nb cavities to arrive at and maintain their operating vacuum pressures. A synopsis of the analysis undertaken to predict the vacuum system performance is also presented.
Date: March 25, 1999
Creator: Hansen, G.; Kishiyama, K.; Shen, S. & Shoaff, P. V.
System: The UNT Digital Library
Observation of ionization instability of intense laser pulses (open access)

Observation of ionization instability of intense laser pulses

Theoretical analysis and preliminary experiment on ionization instability of intense laser pulses in ionizing plasmas are presented. The ionization instability is due to the dependence of the ionization rate on the laser intensity and scatters the laser energy off the original propagation direction.
Date: June 25, 1999
Creator: Alexeev, I.; Antonsen, T. M.; Li, Y.; Milchberg, H. M. & Nikitin, S.
System: The UNT Digital Library