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Eclipsing binary stars in the Large and Small Magellanic Clouds from the MACHO project: The Sample

Description: We present a new sample of 4634 eclipsing binary stars in the Large Magellanic Cloud (LMC), expanding on a previous sample of 611 objects and a new sample of 1509 eclipsing binary stars in the Small Magellanic Cloud (SMC), that were identified in the light curve database of the MACHO project. We perform a cross correlation with the OGLE-II LMC sample, finding 1236 matches. A cross correlation with the OGLE-II SMC sample finds 698 matches. We then compare the LMC subsamples corresponding to cent… more
Date: March 29, 2007
Creator: Faccioli, L.; Alcock, C.; Cook, K.; Prochter, G.; Protopapas, P. & Syphers, D.
Partner: UNT Libraries Government Documents Department
open access

Purgatorio - A new implementation of the Inferno algorithm

Description: For astrophysical applications, as well as modeling laser-produced plasmas, there is a continual need for equation-of-state data over a wide domain of physical conditions. This paper presents algorithmic aspects for computing the Helmholtz free energy of plasma electrons for temperatures spanning from a few Kelvin to several KeV, and densities ranging from essentially isolated ion conditions to such large compressions that most bound orbitals become delocalized. The objective is high precision … more
Date: March 29, 2005
Creator: Wilson, B; Sonnad, V; Sterne, P & Isaacs, W
Partner: UNT Libraries Government Documents Department
open access

Stragegies to Detect Hidden Geothermal Systems Based on Monitoringand Analysis of CO2 in the Near-Surface Environment

Description: We investigate the potential for CO2 monitoring in thenear-surface environment as an approach to exploration for hiddengeothermal systems. Numerical simulations of CO2 migration from a modelhidden geothermal system show that CO2 concentrations can reach highlevels in the shallow subsurface even for relatively low CO2 fluxes.Therefore, subsurface measurements offer an advantage over above-groundmeasurements which are affected by winds that rapidly disperse CO2. Tomeet the challenge of detecting … more
Date: March 29, 2005
Creator: Lewicki, Jennifer L. & Oldenburg, Curtis M.
Partner: UNT Libraries Government Documents Department
open access

Membrane composition analysis by imaging mass spectrometry

Description: Membranes on solid supports offer an ideal format for imaging. Secondary ion mass spectrometry (SIMS) can be used to obtain composition information on membrane-associated components. Using the NanoSIMS50, images of composition variations in membrane domains can be obtained with a lateral resolution better than 100 nm. By suitable calibration, these variations in composition can be translated into a quantitative analysis of the membrane composition. Progress towards imaging small phase-separated… more
Date: March 29, 2006
Creator: Boxer, S G; Kraft, M L; Longo, M; Hutcheon, I D & Weber, P K
Partner: UNT Libraries Government Documents Department
open access

Layered granule chute flow near the angle of repose

Description: A natural, two-layered gravity flow of sand can be obtained on chutes inclined at angles slightly above the angle of repose of the sand. The top-surface layer is free-flowing, is thin, and moves rapidly at supercritical velocity. The velocity depends mainly on the character of the sand and the chute inclination angle. The bottom layer is thick and moves more slowly, with the flow controlled by adjustable weirs at the chute exit. The velocity profile in the thick bottom layer is curved; as much … more
Date: March 29, 1985
Creator: Pitts, J.H. & Walton, O.R.
Partner: UNT Libraries Government Documents Department
open access

Design of aggressive superconducting TFCX magnet systems

Description: An investigation of several fundamental limits of machine design indicate that a machine fitting the specifications of the Tokamak Fusion Core Experiment (TFCX) can be built with both a superconducting toroidal field (TF) coil set and a plasma major radius of less than 3.2 m. This small size is achieved by accepting a peak nuclear heat load of 50 (kW)(m/sup -3/) in the TF coin inner leg while operating at a 10-T maximum field with a current density of 35 (A)(mm/sup -2/) in the winding pack. Thi… more
Date: March 29, 1985
Creator: Miller, J. R.
Partner: UNT Libraries Government Documents Department
open access

Nova laser alignment control system

Description: Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently wi… more
Date: March 29, 1984
Creator: Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L. & Shelton, R.T.
Partner: UNT Libraries Government Documents Department
open access

Computer applications and hybrid microcircuits

Description: The Kansas City Division of the Bendix Corp. is a manufacturing facility. It uses computer graphics to prepare formal drawings in a specified drawing system. Introduction of a system worked out with Sandia Laboratories resulted in reduced time for through-put, faster processing of changes, and steady (rather than increased) employment figures. The system has been in operation for 27 months. It cost about $300,000, and has been used on printed wiring boards, hybrid microcircuits, and test equipm… more
Date: March 29, 1978
Creator: Sheets, L.
Partner: UNT Libraries Government Documents Department
open access

Electromagnetic direct implicit PIC simulation

Description: Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes.
Date: March 29, 1983
Creator: Langdon, A. Bruce
Partner: UNT Libraries Government Documents Department
open access

Fusion-power demonstration. [Next step beyond MFTF-B]

Description: As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envision… more
Date: March 29, 1983
Creator: Henning, C. D.; Logan, B. G.; Carlson, G. A.; Neef, W. S.; Moir, R. W.; Campbell, R. B. et al.
Partner: UNT Libraries Government Documents Department
open access

k-line iterative methods: a conjugate-gradient approach

Description: The generalized conjugate gradient scheme based on the k-line block Jacobi splitting A = M-N was studied for solving model two-dimensional parabolic and elliptic difference equations AU = F tilde. A represents the matrix ch/sup ..cap alpha../-h/sup 2/..delta../sub h/. Eigenvalues of M/sup -1/N cluster, and the cluster radii decrease as ch/sup ..cap alpha../ or k increases. Computations with k = 4, 8, 16, 32, and ch/sup ..cap alpha../ = 0, h, 2 are discussed.
Date: March 29, 1981
Creator: Kratzer, D.; Parter, S.V. & Steuerwalt, M.
Partner: UNT Libraries Government Documents Department
open access

Thick-target yields of iodine isotopes from proton interactions in Te, and the double-[beta] decay of [sup 128,130]Te

Description: We report thick-target yields of [sup 126,128,130]I from the bombardment of natural Te targets with 15-, 30-, 45- and 50-MeV protons, together with the iodine production cross sections for 1.85- and 5.0-GeV protons. With these data, we have estimated the relative cosmic-ray induced production of [sup 126]Xe, [sup 128]Xe and [sup 13O]Xe in Te ores. These quantities affect the ratio of double-[beta] decay half-lives of [sup 13O]Te and [sup 128]Te. A revised correction of cosmic-ray induced xenon … more
Date: March 29, 1993
Creator: da Cruz, M.T.F.; Chan, Y.D.; Garcia, A.; Larimer, R.M.; Lesko, K.T.; Norman, E.B. et al.
Partner: UNT Libraries Government Documents Department
open access

[beta][sup +] decay and cosmic-ray half-life of [sup 54]Mn

Description: We performed a search for the [beta][sup +] branch of [sup 54]Mn decay. As a cosmic ray, [sup 54]Mn, deprived of its atomic electrons, can decay only via [beta][sup +] and [beta][sup [minus]] decay, with a half-life of the order of 10[sup 6] yr. This turns [sup 54] Mn into a suitable cosmic chronometer for the study of cosmic-ray confinement times. We searched for coincident back-to-back 511-keV [gamma]-rays using two germanium detectors inside a Nal(Tl) annulus. An upper limit of 2[times]10[su… more
Date: March 29, 1993
Creator: da Cruz, M.T.F.; Norman, E.B.; Chan, Y.D.; Garcia, A.; Larimer, R.M.; Lesko, K.T. et al.
Partner: UNT Libraries Government Documents Department
open access

{beta}{sup +} decay and cosmic-ray half-life of {sup 54}Mn

Description: We performed a search for the {beta}{sup +} branch of {sup 54}Mn decay. As a cosmic ray, {sup 54}Mn, deprived of its atomic electrons, can decay only via {beta}{sup +} and {beta}{sup {minus}} decay, with a half-life of the order of 10{sup 6} yr. This turns {sup 54} Mn into a suitable cosmic chronometer for the study of cosmic-ray confinement times. We searched for coincident back-to-back 511-keV {gamma}-rays using two germanium detectors inside a Nal(Tl) annulus. An upper limit of 2{times}10{su… more
Date: March 29, 1993
Creator: da Cruz, M. T. F.; Norman, E. B.; Chan, Y. D.; Garcia, A.; Larimer, R. M.; Lesko, K. T. et al.
Partner: UNT Libraries Government Documents Department
open access

A parallel hashed oct-tree N-body algorithm

Description: We report on an efficient adaptive N-body method which we have recently designed and implemented. The algorithm computers the forces on an arbitrary distribution of bodies in a time which scales as N log N with particle number. The accuracy of the force calculations is analytically bounded, and can be adjusted via a user defined parameter between a few percent relative accuracy, down to machine arithmetic accuracy. Instead of using pointers to indicate the topology of the tree, we identify each… more
Date: March 29, 1993
Creator: Warren, M. S. & Salmon, J. K.
Partner: UNT Libraries Government Documents Department
open access

Silicon microelectronic field-emissive devices for advanced display technology

Description: Field-emission displays (FEDS) offer potential advantages of high luminous efficiency, low power consumption, and low cost compared to AMLCD or CRT technologies. An LLNL team has developed silicon-point field emitters for vacuum triode structures and has also used thin-film processing techniques to demonstrate planar edge-emitter configurations. LLNL is interested in contributing its experience in this and other FED-related technologies to collaborations for commercial FED development. At LLNL,… more
Date: March 29, 1993
Creator: Morse, J. D.
Partner: UNT Libraries Government Documents Department
open access

Gold Beam Losses at the AGS Booster Injection.

Description: Gold beam injection efficiency decreases in proportional to the beam loss in the AGS Booster. A close look shows that large number of electrons, ions, and neutral particles are created when the gold beam scrapes wall. To investigate the neutral particle production due to the beam loss, local vacuum measurement was made during the 1998 run. It shows that the pressure created by the Booster Au{sup 31+} beam loss at injection has a 35 ms decay time constant. The beam loss created pressure bump in … more
Date: March 29, 1999
Creator: Zhang, S. Y. & Ahrens, L. A.
Partner: UNT Libraries Government Documents Department
open access

A Cupronickel Rotating Band Pion Production Target for Muon Colliders.

Description: A conceptual design is presented for a high power cupronickel pion production target. It forms a circular band in a horizontal plane with approximate dimensions of: 2.5 meters radius, 6 cm high and 0.6 cm thick. The target is continuously rotated at 3 m/s to carry heat away from the production region to a water cooling channel. Bunches of 16 GeV protons with total energies of 270 kl and repetition rates of 15 Hz are incident tangentially to arc of the target along the symmetry axis of a 20 Tesl… more
Date: March 29, 1999
Creator: King, B. J.; Weggel, R. J.; Mokhov, N. V. & Moser, S. S.
Partner: UNT Libraries Government Documents Department
open access

Influences on the Height of the Stable Boundary Layer as seen in Large-Eddy Simulations

Description: Numerical weather prediction (NWP) models and atmospheric dispersion models rely on parameterizations of planetary boundary layer height. In the case of a stable boundary layer, errors in boundary layer height estimation can result in gross errors in boundary-layer evolution and in prediction of turbulent mixing within the boundary layer. We use large-eddy simulations (LES) of moderately stable boundary layers to characterize the effects of various physical processes on stable boundary layers. … more
Date: March 29, 2004
Creator: Kosovic, B & Lundquist, J K
Partner: UNT Libraries Government Documents Department
open access

Precision Magnetic Elements for the SNS Storage Ring.

Description: Magnetic elements for an accumulator storage ring for a 1 GeV Spallation Neutron Source (SNS) have been under design. The accumulation of very high intensity protons in a storage ring requires beam optical elements of very high purity to minimize higher order resonances in the presence of space charge. The parameters of the elements required by the accumulator lattice design have been reported. The dipoles have a 17cm gap and are 124cm long. The quadrupoles have a physical length to aperture di… more
Date: March 29, 1999
Creator: Danby, G.; Jackson, J. & Spataro, C.
Partner: UNT Libraries Government Documents Department
open access

A P-Carbon CNI Polarimeter for RHIC.

Description: The RHIC spin program requires excellent polarimetry so that the knowledge of the beam polarization does not limit the errors on the experimental measurements. However, polarimetry of proton beams with energies higher than about 30GeV poses a difficult challenge. For polarization monitoring during operation, a fast and reliable polarimeter is required that produces a polarization measurement with a 10% relative error within a few minutes. The p-Carbon elastic scattering in the Coulomb-Nuclear-S… more
Date: March 29, 1999
Creator: Huang, H.; Bai, M.; Bunce, G.; Makdisi, Y.; Roser, T.; Imai, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Design of a Resonant Extraction System for the AGS Booster.

Description: The Booster Application Facility (BAF) will employ heavy ion beams of many different ion species and at beam energies ranging from 0.04 to 3.07 GeV/nucleon. Resonant extraction is required in order to deliver a continuous stream of particles. In this report we describe the beam requirements and the system design. The basic design is a third integer resonant extraction process which employs a single thin magnetic septum and a thick septum ejector magnet The expected extraction efficiency is abou… more
Date: March 29, 1999
Creator: Brown, K.; Cullen, J.; Glenn, J. W.; Lee, Y. Y.; Mcnerney, A.; Niederer, J. et al.
Partner: UNT Libraries Government Documents Department
open access

RHIC Beam Loss Monitor System Initial Operation.

Description: The RHIC Beam Loss Monitor (BLM) System is designed to prevent beam loss quenching of the superconducting magnets, and acquire loss data. Four hundred ion chambers are located around the rings to detect losses. The required 8-decade range in signal current is compressed using an RC pre- integrator ahead of a low current amplifier. A beam abort may be triggered if fast or slow losses exceed programmable threshold levels. A micro-controller based VME module sets references and gains and reads tri… more
Date: March 29, 1999
Creator: Witkover, R. L.; Michnoff, R. J. & Geller, J. M.
Partner: UNT Libraries Government Documents Department
open access

The Design of a Liquid Lithium Lens for a Muon Collider.

Description: The last stage of ionization cooling for the muon collider requires a multistage liquid lithium lens. This system uses a large ({approx}0.5 MA) pulsed current through liquid lithium to focus the beam while energy loss in the lithium removes momentum which will be replaced by linacs. The beam optics are designed to maximize the 6 dimensional transmission from one lens to the next while minimizing emittance growth. The mechanical design of the lithium vessel is constrained by a pressure pulse due… more
Date: March 29, 1999
Creator: Hassanein, A.; Norem, J.; Reed, C.; Palmer, R. B.; Silvestrov, G.; Vsevolozhskaya, T. A. et al.
Partner: UNT Libraries Government Documents Department
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