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2-D Simulations of Drainage Winds and Diffusion Compared to Observations
A vertically integrated dynamical drainage flow model is developed from conservation equations for momentum and mass in a terrain-following coordinate system. Wind fields from the dynamical model drive a Monte Carlo transport and diffusion model. The model needs only topographic data, an Eulerian or Lagrangian time scale and a surface drag coefficient for input data, and can be started with a motionless atmosphere. Model wind and diffusion predictions are compared to observations from the rugged Geysers CA area. Model winds generally agree with observed surface winds, and in some cases may give better estimates of area-averaged flow than point observations. Tracer gas concentration contours agree qualitatively with observed contours, and point predictions of maximum concentrations were correctly predicted to within factors of 2 to 10. Standard statistical tests of model skill showed that the accuracy of the predictions varied significantly from canyon to canyon in the Geysers are a. Model wind predictions are also compared to observations from the Savannah River Plant of SC which has gently rolling terrain. The model correctly simulated the slower development of drainage winds and slower deepening of the drainage layer in the Savannah River Valley, relative to the Geysers CA simulations. The SC simulations …
Date:
May 29, 2001
Creator:
Garrett, A. J.
System:
The UNT Digital Library
2-D Tomography With Bolometry in DIII-D
We have installed a 48-channel platinum-foil bolometer system on DIII-D achieve better spatial and temporal resolution of the radiated power in diverted discharges. Two 24-channel arrays provide complete plasma coverage with optimized views of the divertor. We have measured the divertor radiation profile for a series of radiative divertor and power balance experiments. We observe a rapid change in the magnitude and distribution of divertor radiation with heavy gas puffing. Unfolding the radiation profile with only two views requires us to treat the core and divertor radiation separately. The core radiation is fitted to a function of magnetic flux and is then subtracted from the divertor viewing chords. The divertor profile is then fit to a 2-D spline as a function of magnetic flux and poloidal angle.
Date:
July 1, 1994
Creator:
Leonard, A. W.; Meyer, W. H.; Geer, B.; Behne, D. M. & Hill, D. N.
System:
The UNT Digital Library
S = -2 dibaryons and hypernuclei
Future prospects for the exploration of doubly strange hypernuclear systems are evaluated. Such systems may be produced via the double strangeness exchange reactions (K/sup -/,K/sup +/) or (K/sup -/,K/sup 0/) on nuclear targets. Theoretical estimates are given of the formation cross sections for Xi/sup -/ hypernuclear states via the one-step K/sup -/p ..-->.. K/sup +/Xi/sup -/ process, or discrete states of the ..lambda lambda.. hypernucleus in the two step reaction K/sup -/p ..-->.. ..pi../sup 0/..lambda.. followed by ..pi../sup 0/p ..-->.. K/sup +/..lambda... Recently, there has been much discussion of six quark (dibaryon) states in the Bag Model. Arguments are given which indicate that the (K/sup -/,K/sup +/) reaction on light nuclear targets (ex. /sup 3/He) affords a very promising way of producing the lowest-lying S = -2 dibaryon (called the H).
Date:
January 1, 1982
Creator:
Dover, C.B.
System:
The UNT Digital Library
A 2-GHz Rectangular Corrugated Horn
We have designed, constructed and tested a large, rectangular horn antenna with a center frequency of 2.0 GHz, corrugated on the E-plane walls, made out of aluminum sheet. A new technique has been developed to solder thin aluminum strips onto the back plane to form the corrugations. The radiation beam pattern shows half-power beamwidths of 12{sup 0} and 14{sup 0} in the H and E planes respectively, and side lobe response below -40 dB at angles greater than 50{sup 0} from horn axis. The measured return loss is less than -20 dB (VSWR < 1.22) between 1.7 and 2.3 GHz; insertion loss is less than 0.15 dB.
Date:
October 1, 1991
Creator:
Bersanelli, M.; Bensadoun, M.; De Amici, Giovanni; Limon, M.; Smoot, George F.; Tanaka, S. et al.
System:
The UNT Digital Library
A 2-Liter, 2000 MPa Air Source for the Radiatively Driven Hypersonic Wind Tunnel
The A2 LITE is a 2 liter, 2000 MPa, 750 K ultra-high pressure (UHP) vessel used to demonstrate UHP technology and to provide an air flow for wind tunnel nozzle development. It is the largest volume UHP vessel in the world. The design is based on a 100:1 pressure intensification using a hydraulic ram as a low pressure driver and a three-layer compound cylinder UHP section. Active control of the 900 mm piston stroke in the 63.5 mm bore permits pressure-time profiles ranging from static to constant pressure during flow through a 1 mm throat diameter nozzle for 1 second.
Date:
May 30, 2002
Creator:
Costantino, M & Lofftus, D
System:
The UNT Digital Library
N = 2 Maxwell-Einstein Supergravity Theories: Their Compact and Non-Compact Gaugings and Jordan Algebras
In this talk we give a review of our work on the construction and classification of N = 2 Maxwell-Einstein Supergravity theories (MESGT), study of the underlying algebraical and geometrical structure of these theories, and their compact and non-compact gaugings. We begin by summarizing our construction of the N = 2 MESGT's in five dimensions and give a geometrical interpretation to various scalar dependent quantities in the Lagrangian, based on the constraiants implied by supersymmetry. This is followed by a complete classification of the N = 2 MESGT's whose target manifolds parametrized by the scalar fields are symmetric spaces. 39 refs.
Date:
January 1, 1985
Creator:
Guenaydin, M.; Sierra, G. & Townsend, P.K.
System:
The UNT Digital Library
2 meg-ampere prototype levitated coil for multipole fusion
The coils major diameter is 1.0 meter and it occupies a cross-section which is about 0.2 meter minor in diameter. The prototype coil will carry four times the current of the largest such magnet built to date. As a result, the peak induction in the coil is about 8 T and the stored magnetic energy will be around 3 MJ. The paper describes the proposed Nb/sub 3/SN superconductor, the quench protection system which is based on the LBL shorted secondary concept, the isochroic refrigeration storage system which stores about 5 kJ of refrigeration between 4.5/sup 0/K and 7/sup 0/K, and the persistent switch.
Date:
November 1, 1979
Creator:
Green, M. A. & Glueck, R.
System:
The UNT Digital Library
A 2-Megawatt load for testing high voltage dc power supplies
A high power water-cooled resistive load, capable of dissipating 2 Megawatts at 95 kilovolts is being designed and built. The load utilizes wirewound resistor elements suspended inside insulating tubing contained within a pressure vessel which is supplied a continuous flow of deionized water for coolant. A sub-system of the load is composed of non-inductive resistor elements in an oil tank. Power tests conducted on various resistor types indicate that dissipation levels as high as 22 times the rated dissipation in air can be achieved when the resistors are placed in a turbulent water flow of at least 15 gallons per minute. Using this data, the load w.as designed using 100 resistor elements in a series arrangement A single-wall 316 stainless steel pressure vessel with flanged torispherical heads is built to contain the resistor assembly and deionized water. The resistors are suspended within G-11 tubing which span the cylindrical length of the vessel. These tubes are supported by G-10 baffles which also increase convection from the tubes by promoting turbulence within the surrounding water.
Date:
June 1, 1993
Creator:
Horan, D.; Kustom, R.; Ferguson, M. & Primdahl, K.
System:
The UNT Digital Library
A 2-MeV microwave thermionic gun
A high-gradient, S-band microwave gun with a thermionic cathode is being developed in a collaborative effort by AET, Varian, and SSRL. A prototype design using an upgraded Varian dispenser cathode mounted with thermal isolation directly in the first half-cell of a 1-1/2 cell, side-coupled, standing-wave cavity has been fabricated and is being tested. Optimization of the cavity shape and beam formation was done using SUPERFISH, MASK, and PARMELA. An overview of design details, as well as the status of in-progress beam tests, will be presented. 9 refs., 6 figs.
Date:
August 1, 1989
Creator:
Tanabe, E.; Borland, M.; Green, M. C.; Miller, R. H.; Nelson, L. V.; Weaver, J. N. et al.
System:
The UNT Digital Library
2-MV electrostatic quadrupole injector for heavy-ion fusion
High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole (ESQ) injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV Injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment (HCX) and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.
Date:
November 10, 2004
Creator:
Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L. & Seidl, P. A.
System:
The UNT Digital Library
A 2-MV multi-beam injector for heavy ion fusion
Construction of a sixteen beam (0.5 A per beam) injector for use in scaled heavy ion fusion experiments is underway at LBL. The machine was designed and partially constructed at LANL. The injector is designed to use carbon arc sources which will provide 25 mA/cm/sup 2/ of extractable current density. The plasma from the arcs is confined electrostatically from drifting into the ion gun before firing the extraction pulse. The acceleration column consists of a set of aperture lenses which both transport the beam and attenuate backstreaming electrons. The acceleration column is mounted inside a 28-inch diameter brazed alumina insulating module. The high voltage for the injector is provided by an inductively loaded and graded Marx generator which resides inside a pressure vessel filled with a 65 psig mixture of 30/percent/ SF/sub 6/ and 70/percent/ N/sub 2/. Data is presented showing the performance of single and multiple carbon arc sources. Measurements show that adequate current density is available. Emittance measurements and efforts to improve emittance and reproducibility are shown. Tests with a 5-tray section of the full 18 tray generator are described showing the evolution of the generator design. 5 refs., 3 figs.
Date:
June 1, 1988
Creator:
Rutkowski, H. L.; Faltens, A.; Vanecek, D.; Pike, C.; Humphries, S., Jr. & Meyer, E. A.
System:
The UNT Digital Library
2 MW 110 GHz ECH heating system for DIII-D
A 2 MW 110 GHz ECH system using Varian 0.5 MW gyrotrons is under construction for use on the DIII-D tokamak by late 1991. Most of the components are being design and fabricated at General Atomics, including the gyrotron tanks, superconducting magnets, and transmission line. These components are intended for operation with 10 second pulses and, in the future, with 1 MW gyrotrons. 6 refs., 5 figs.
Date:
September 1990
Creator:
Moeller, C.; Prater, R.; Callis, R.; Remsen, D.; Doane, J.; Cary, W. et al.
System:
The UNT Digital Library
2 MW upgrade of the Fermilab Main Injector
In January 2002, the Fermilab Director initiated a design study for a high average power, modest energy proton facility. An intensity upgrade to Fermilab's 120-GeV Main Injector (MI) represents an attractive concept for such a facility, which would leverage existing beam lines and experimental areas and would greatly enhance physics opportunities at Fermilab and in the U.S. With a Proton Driver replacing the present Booster, the beam intensity of the MI is expected to be increased by a factor of five. Accompanied by a shorter cycle, the beam power would reach 2 MW. This would make the MI a more powerful machine than the SNS or the J-PARC. Moreover, the high beam energy (120 GeV) and tunable energy range (8-120 GeV) would make it a unique high power proton facility. The upgrade study has been completed and published. This paper gives a summary report.
Date:
June 4, 2003
Creator:
Chou, Weiren
System:
The UNT Digital Library
2-pi Photoproduction from CLAS and CB-ELSA - The Search for Missing Resonances
2-pi-photoproduction is one of the promising reactions to search for baryon resonances that have been predicted but have not yet been observed. The gamma-rho --> rho-pi{sup 0}-pi{sup 0}(CB-ELSA) and the gamma-rho --> rho-pi{sup +}-pi{sup -} (CLAS) data show interesting resonance structures. A partial wave analysis (PWA) has to be done to determine which baryon resonances contribute what their quantum numbers and their relative couplings to the different accessible rho-2-pi-channels and to the photon are. First preliminary PWA-results on the lowest energy rho-pi{sup 0}-pi{sup 0} data (sq rt s<1.8 GeV)look very promising. From an extension of this analysis to higher energies combining the rho-pi{sup 0}-pi{sup 0} and the rho-pi{sup +}-pi{sup -}-data, one can expect; interesting results on resonances decaying into Delta-pi, N-rho, N(pi-pi)s, N*-pi, and Delta*-pi.
Date:
October 1, 2003
Creator:
Thoma, Ulrike
System:
The UNT Digital Library
N = 2 string amplitudes
In physics, solvable models have played very important roles. Understanding a simple model in detail teaches us a lot about more complicated models in generic situations. Five years ago, C. Vafa and I found that the closed N = 2 string theory, that is a string theory with the N = 2 local supersymmetry on the worldsheet, is classically equivalent to the self-dual Einstein gravity in four spacetime dimensions. Thus this string theory is solvable at the classical level. More recently, we have examined the N = 2 string partition function for spacial compactifications, and computed it to all order in the string perturbation expansion. The fact that such computation is possible at all suggests that the N = 2 string theory is solvable even quantum mechanically.
Date:
August 1, 1995
Creator:
Ooguri, H.
System:
The UNT Digital Library
2$sup 0$K vacuum pumping system for Baseball II
A vacuum pumping system that provides a cryo surface for condensing and freezing of H/sub 2/ gas is described. A closed-loop vacuum system was designed and built at Lawrence Livermore Laboratory to pump down the neutralizer LH/sub e/ dewar with a volurae of 350 l and the lambda point dewar with a LH/sub e/ volume of 250 l. Both of these dewars can be pumped down simultaneously or one at a time. 100% of the H/sub e/ gas is recovered free of contaminations. The vacuum pump can handle 340 SCFM of gas. The LH/sub e/ dewars are pumped down below the lambda point. This condition reduces the LH/sub e/ container wall temperature to 2.1 deg K giving a base pressure of 10/sup -13/ torr for H/sub 2/ gas/sup 2/. To attain a stable condition the LH /sub e/ baths are puuped down to 33 torr or lower to give a surface temperatare of about 2/sup 0/K/sup 3/. The Baseball II helium factlity is a close loop system. The H/sub e/ gas is recovered from all the LH/sub e/ usage point. This gas is accumulated in one of the two 8000 cu ft inflatable gas bags. The gas from the gas …
Date:
August 20, 1973
Creator:
Denhoy, B.S.
System:
The UNT Digital Library
2 {times} 2 TeV {mu}{sup +}{mu}{sup {minus}} collider: Lattice and accelerator-detector interface study
The design for a high-luminosity {mu}{sup +}{mu}{sup {minus}} superconducting storage ring is presented based on first-pass calculations. Special attention is paid to two Iowa interaction regions (IR) whose optics are literally interlaced with the collider detectors. Various sources of backgrounds in IR are explored via realistic Monte Carlo simulations. An improved design of the collider lattice in the neighborhood of the interaction points (EP) is determined by the need to reduce significantly background levels in the detectors.
Date:
May 1, 1995
Creator:
Gelfand, N. M. & Mokhov, N. V.
System:
The UNT Digital Library
A 2 to 4 nm high power FEL on the SLAC linac
We report the results of preliminary studies of a 2 to 4 nm SASE FEL, using a photoinjector to produce the electron beam, and the SLAC linac to accelerate it to an energy up to 10 GeV. Longitudinal bunch compression is used to increases ten fold the peak current to 2.5 kA, while reducing the bunch length to the subpicosecond range. The saturated output power is in the multi-gigawatt range, producing about 10{sup 14} coherent photons within a bandwidth of about 0.2% rms, in a pulse of several millijoules. At 120Hz repetition rate the average power is about 1 W. The system is optimized for x-ray microscopy in the water window around 2 to 4 nm, and will permit imaging a biological sample in a single subpicosecond pulse.
Date:
September 1, 1992
Creator:
Pellegrini, C.; Rosenzweig, J.; Nuhn, H. D.; Pianetta, P.; Tatchyn, R.; Winick, H. et al.
System:
The UNT Digital Library
2 x 2 TeV mu(superscript +) mu (superscript) collider
The scenarios for high-luminosity 2 x 2 TeV and 250 x 250 GeV {mu}{sup +}{mu}{sup -} colliders are presented. Having a high physics potential, such a machine has specific physics and technical advantages and disadvantages when compared with an e{sup +}e{sup -} collider. Parameters for the candidate designs and the basic components - proton source, pion production and decay channel, cooling, acceleration and collider storage ring - are considered. Attention is paid to the areas mostly affecting the collider performance: targetry, energy spread, superconducting magnet survival, detector backgrounds, polarization, environmental issues. 13 refs., 9 figs., 4 tabs.
Date:
October 1, 1996
Creator:
Mokhov, N. V. & Noble, R. J.
System:
The UNT Digital Library
3,2-HOPO Complexes of Near-Infra-Red (NIR) Emitting Lanthanides: Sensitization of Ho(III) and Pr(III) in Aqueous Solution
There is a growing interest in Near Infra-Red (NIR) emission originating from organic complexes of Ln{sup III} cations. As a major impetus, biological tissues are considerably more transparent at these low energy wavelengths when compared to visible radiation, which facilitates deeper penetration of incident and emitted light. Furthermore, the long luminescence lifetimes of Ln{sup III} complexes (eg. Yb{sup III}, {tau}{sub rad} {approx} 1 ms) when compared to typical organic molecules can be utilized to vastly improve signal to noise ratios by employing time-gating techniques. While the improved quantum yield of Yb{sub III} complexes when compared to other NIR emitters favors their use for bioimaging applications, there has also been significant interest in the sensitized emission from other 4f metals such as Ln = Nd, Ho, Pr and Er which have well recognized applications as solid state laser materials (eg. Nd {approx} 1.06 {micro}m, Ho {approx} 2.09 {micro}m), and in telecommunications (eg. Er {approx} 1.54 {micro}m) where they can be used for amplification of optical signals. As a result of their weak (Laporte forbidden) f-f absorptions, the direct excitation of Ln{sup III} cations is inefficient, and sensitization of the metal emission is more effectively achieved using the so-called antenna effect. We …
Date:
May 19, 2008
Creator:
Moore, Evan G.; Szigethy, Geza; Xu, Jide; Palsson, Lars-Olof; Beeby, Andrew & Raymond, Kenneth N.
System:
The UNT Digital Library
A 3.3 MJ, Rb + 1 driver design based on an integrated systems analysis
A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.
Date:
March 7, 2000
Creator:
Meier, W. R.; Barnard, J. J. & Bangerter, R. O.
System:
The UNT Digital Library
A 3.3 MJ, Rb{sup +1} Driver Design Based on an Integrated Systems Analysis
A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.
Date:
September 15, 2000
Creator:
Meier, W. R.; Barnard, J. J. & Bangerter, R. O.
System:
The UNT Digital Library
3,4,3-LI(1,2-HOPO): In Vitro Formation of Highly Stable Lanthanide Complexes Translates into Efficacious In Vivo Europium Decorporation
The spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) was investigated for its ability to act as an antennae that sensitizes the emission of Sm{sup III}, Eu{sup III}, and Tb{sup III} in the Visible range (Φ{sub tot} = 0.2 - 7%) and the emission of Pr{sup III}, Nd{sup III}, Sm{sup III}, and Yb{sup III} in the Near Infra-Red range, with decay times varying from 1.78 μs to 805 μs at room temperature. The particular luminescence spectroscopic properties of these lanthanide complexes formed with 3,4,3-LI(1,2-HOPO) were used to characterize their respective solution thermodynamic stabilities as well as those of the corresponding La{sup III}, Gd{sup III}, Dy{sup III}, Ho{sup III}, Er{sup III}, Tm{sup III}, and Lu{sup III} complexes. The remarkably high affinity of 3,4,3-LI(1,2-HOPO) for lanthanide metal ions and the resulting high complex stabilities (pM values ranging from 17.2 for La{sup III} to 23.1 for Yb{sup III}) constitute a necessary but not sufficient criteria to consider this octadentate ligand an optimal candidate for in vivo metal decorporation. The in vivo lanthanide complex stability and decorporation capacity of the ligand were assessed, using the radioactive isotope {sup 152}Eu as a tracer in a rodent model, which provided a direct comparison with the in vitro thermodynamic results …
Date:
July 13, 2011
Creator:
Sturzbecher-Hoehne, Manuel; Ng Pak Leung, Clara; Daleo, Anthony; Kullgren, Birgitta; Prigent, Anne-Laure; Shuh, David K. et al.
System:
The UNT Digital Library
3,5-Bis(4-chlorobenzylidene)-1-methyl-piperidin-4-one
In the title molecule, C₂₀H₁₇Cl₂NO, the central heterocyclic ring adopts a flattened boat conformation.
Date:
February 23, 2011
Creator:
Nesterov, Volodymyr V.; Sarkisov, Sergey S.; Shulaev, Vladimir & Nesterov, Vladimir N.
System:
The UNT Digital Library