November 10, 1998 Physics Design of the National Spherical Torus
1 Abstract The mission of the National Spherical Torus Experiment (NSTX) is to prove the principles an attractive path to a reactor or Volumetric Neutron Source (VNS). The ST fusion core would be small, economic and is presently under construction. Various reactor concepts have been advanced for the ST, 7,8 and these have
Vessel eddy current measurement for the National Spherical Torus Experiment
Gates, D.A.; Menard, J.E.; Marsala, R.J. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)
2004-12-01T23:59:59.000Z
A simple analog circuit that measures the National Spherical Torus Experiment (NSTX) axisymmetric eddy current distribution has been designed and constructed. It is based on simple circuit model of the NSTX vacuum vessel that was calibrated using a special axisymmetric eddy current code which was written so that accuracy was maintained in the vicinity of the current filaments [J. Menard, J. Fusion Tech. (to be published)]. The measurement and the model have been benchmarked against data from numerous vacuum shots and they are in excellent agreement. This is an important measurement that helps give more accurate equilibrium reconstructions.
Divertor Heat Flux Mitigation in the National Spherical Torus Experiment
Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D
2008-08-04T23:59:59.000Z
Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.
Measurement of Poloidal Velocity on the National Spherical Torus Experiment
Ronald E. Bell and Russell Feder
2010-06-04T23:59:59.000Z
A diagnostic suite has been developed to measure impurity poloidal flow using charge exchange recombination spectroscopy on the National Spherical Torus Experiment. Toroidal and poloidal viewing systems measure all quantities required to determine the radial electric field. Two sets of up/down symmetric poloidal views are used to measure both active emission in the plane of the neutral heating beams and background emission in a radial plane away from the neutral beams. Differential velocity measurements isolate the line-integrated poloidal velocity from apparent flows due to the energy-dependent chargeexchange cross section. Six f/1.8 spectrometers measure 276 spectra to obtain 75 active and 63 background channels every 10 ms. Local measurements from a similar midplane toroidal viewing system are mapped into two dimensions to allow the inversion of poloidal line-integrated measurements to obtain local poloidal velocity profiles. Radial resolution after inversion is 0.6-1.8 cm from the plasma edge to the center.
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta...
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta... A; published online 23 April 2004 Ion absorption of the high harmonic fast wave in a spherical torus Y.-K. M power are injected into the plasma simultaneously, a fast ion population with energy above the beam
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a...
Egedal, Jan
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a; published online 23 April 2004# Ion absorption of the high harmonic fast wave in a spherical torus #Y.K. M neutral beam and rf power are injected into the plasma simultaneously, a fast ion population with energy
November 10, 1998 Physics Design of the National Spherical Torus
NSTX is to prove the principles of spherical torus physics by producing high- t plasmas that are non an attractive path to a reactor or VolumetricNeutron Source VNS.The ST fusion core would be small under construction. Various reactor concepts have been advanced for the ST,7,8 and these have identi ed
New Capabilities and Results for the National Spherical Torus Experiment
M.G. Bell, R.E. Bell, D.A. Gates, S.M. Kaye, H. Kugel, B.P. LeBlanc, F.M. Levinton, R. Maingi, J.E. Menard, R. Raman, S.A. Sabbagh, D. Stutman and the NSTX Research Team
2008-02-29T23:59:59.000Z
The National Spherical Torus Experiment (NSTX) produces plasmas with toroidal aspect ratio as low as 1.25, which can be heated by up to 6 MW High-Harmonic Fast Waves and up to 7 MW of deuterium Neutral Beam Injection. Using new poloidal fields coils, plasmas with cross-section elongation up to 2.7, triangularity 0.8, plasma currents Ip up to 1.5 MA and normalized currents Ip/a?BT up to 7.5 MA/m?T have been achieved. A significant extension of the plasma pulse length, to 1.5 s at a plasma current of 0.7 MA, has been achieved by exploiting the bootstrap and NBI-driven currents to reduce the dissipation of poloidal flux. Inductive plasma startup has been supplemented by Coaxial Helicity Injection (CHI) and the production of persistent current on closed flux surfaces by CHI has now been demonstrated in NSTX. The plasma response to magnetic field perturbations with toroidal mode numbers n = 1 or 3 and the effects on the plasma rotation have been investigated using three pairs of coils outside the vacuum vessel. Recent studies of both MHD stability and of transport benefitted from improved diagnostics, including measurements of the internal poloidal field using the motional Stark effect (MSE). In plasmas with a region of reversed magnetic shear in the core, now confirmed by the MSE data, improved electron confinement has been observed.
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment
Biewer, Theodore
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment T al., Fusion Technology 30, 1337 (1996)] measures the velocity distribution of ions in the plasma edge power High Harmonic Fast Wave (HHFW) rf heating in helium plasmas, with the poloidal ion temperature
Status of the control system on the National Spherical Torus Experiment (NSTX)
Princeton Plasma Physics Laboratory
#61 final Status of the control system on the National Spherical Torus Experiment (NSTX) D. A Abstract In 2003, the NSTX plasma control system was used for plasma shape control using real. More recently, the system has been upgraded to support feedback control of the resistive wall mode (RWM
National Spherical Torus Experiment (NSTX) | Princeton Plasma Physics Lab
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex andFOURPhoto ofAdministration |Science National SecurityA
Spherical torus fusion reactor
Peng, Yueng-Kay M. (Oak Ridge, TN)
1989-01-01T23:59:59.000Z
A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.
Mazzucato, E.; Bell, R. E.; Ethier, S.; Hosea, J. C.; Kaye, S. M.; LeBlanc, B. P.; Lee, W. W.; Ryan, P. M.; Smith, D. R.; Wang, W. X.; Wilson, J. R.
2009-03-26T23:59:59.000Z
Various theories and numerical simulations support the conjecture that the ubiquitous problem of anomalous electron transport in tokamaks may arise from a short-scale turbulence driven by the electron temperature gradient. To check whether this turbulence is present in plasmas of the National Spherical Torus Experiment (NSTX), measurements of turbulent fluctuations were performed with coherent scattering of electromagnetic waves. Results from plasmas heated by high harmonic fast waves (HHFW) show the existence of density fluctuations in the range of wave numbers k??e=0.1-0.4, corresponding to a turbulence scale length of the order of the collisionless skin depth. Experimental observations and agreement with numerical results from the linear gyro-kinetic GS2 code indicate that the observed turbulence is driven by the electron temperature gradient. These turbulent fluctuations were not observed at the location of an internal transport barrier driven by a negative magnetic shear.
Approval of CD-2 for the National Spherical Torus Experiment (NSTX) Upgrade Project
Princeton Plasma Physics Laboratory
of compact and high normalized pressure "spherical torus" (ST) magnetic fusion plasmas. The compact a predictive capability for magnetic confinement generally. The new center-stack would double the NSTX toroidal: "Priorities, Gaps and Opportunities: Towards A Long-Range Strategic Plan for Magnetic Fusion Energy". More
Direct X-B mode conversion for high-? national spherical torus experiment in nonlinear regime
Ali Asgarian, M., E-mail: maliasgarian@ph.iut.ac.ir, E-mail: maa@msu.edu [Physics Department, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of); Department of Electrical and Computer Engineering, Michigan State University, Michigan 48824-1226 (United States); Parvazian, A.; Abbasi, M. [Physics Department, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of); Verboncoeur, J. P. [Department of Electrical and Computer Engineering, Michigan State University, Michigan 48824-1226 (United States)
2014-09-15T23:59:59.000Z
Electron Bernstein wave (EBW) can be effective for heating and driving currents in spherical tokamak plasmas. Power can be coupled to EBW via mode conversion of the extraordinary (X) mode wave. The most common and successful approach to study the conditions for optimized mode conversion to EBW was evaluated analytically and numerically using a cold plasma model and an approximate kinetic model. The major drawback in using radio frequency waves was the lack of continuous wave sources at very high frequencies (above the electron plasma frequency), which has been addressed. A future milestone is to approach high power regime, where the nonlinear effects become significant, exceeding the limits of validity for present linear theory. Therefore, one appropriate tool would be particle in cell (PIC) simulation. The PIC method retains most of the nonlinear physics without approximations. In this work, we study the direct X-B mode conversion process stages using PIC method for incident wave frequency f{sub 0}?=?15?GHz, and maximum amplitude E{sub 0}?=?10{sup 5?}V/m in the national spherical torus experiment (NSTX). The modelling shows a considerable reduction in X-B mode conversion efficiency, C{sub modelling}?=?0.43, due to the presence of nonlinearities. Comparison of system properties to the linear state reveals predominant nonlinear effects; EBW wavelength and group velocity in comparison with linear regime exhibit an increment around ?36% and 17%, respectively.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gerhardt, S. P.; Fredrickson, E.; Guttadora, L.; Kaita, R.; Kugel, H.; Menard, J.; Takahashi, H.
2011-01-01T23:59:59.000Z
This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments. The measurements are based on three techniques: (i) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (ii) the direct measurement of halo currents into specially instrument tiles, and (iii) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peakingmore »factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems is shown.« less
A Megawatt-level 28z GHz Heating System For The National Spherical Torus Experiment Upgrade
Taylor, Gary
2014-04-01T23:59:59.000Z
The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at axial toroidal fields of < 1 T and plasma currents, Ip < 2 MA. The development of non-inductive (NI) plasmas is a major long-term research goal for NSTX-U. Time dependent numerical simulations of 28 GHz electron cyclotron (EC) heating of low density NI start-up plasmas generated by Coaxial Helicity Injection (CHI) in NSTX-U predict a significant and rapid increase of the central electron temperature (Te(0)) before the plasma becomes overdense. The increased Te(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. A megawatt-level, 28 GHz electron heating system is planned for heating NI start-up plasmas in NSTX-U. In addition to EC heating of CHI start-up discharges, this system will be used for electron Bernstein wave (EBW) plasma start-up, and eventually for EBW heating and current drive during the Ip flattop.
Dynamical Evolution of Pedestal Parameters in ELMy H-mode in the National Spherical Torus Experiment
Diallo, A; Kubota, S; Sontag, A; Osborne, T; Podesta, M; Bell, R E; LeBlanc, B P; Menard, J
2011-07-27T23:59:59.000Z
Characterizations of the pedestal parameter dynamics throughout the edge localized modes(ELM) cycles are performed on the National Spherical Torus Experiment (NSTX, [M. Ono et al., Nucl. Fusion 40, 557 (2000)]). A clear buildup of the pedestal height is observed between ELMs for three di erent plasma currents, which tends to saturate prior to the onset of ELM at low and medium plasma current. Similarly, the pedestal width increases with no clear evidence of saturation during an ELM cycle. The maximum pedestal gradient increases as a function of plasma current, reaches a nominal value after the ELM crash, and remains constant until the end of the ELM cycle. The pedestal height just prior to the onset of ELM is shown to increase quadratically with plasma current. The pedestal width ? is proportional to the square-root of the poloidal ? at the top of the pedestal. Coherent density uctuations strongly increasing at the plasma edge are observed to be maximum after the ELM crash and to decay during the rest of the ELM cycle. Finally, the pedestal parameters evolution during the ELM cycle as well as the scaling with Ip of the pedestal pressure prior to the onset ELM are found to be qualitatively consistent with the peeling ballooning theory.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Fredrickson, E. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Guttadora, L. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Kugel, H. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Menard, J. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Takahashi, H. [Princeton Fusion Research LLC, Princeton, NJ (United States)
2011-01-01T23:59:59.000Z
This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments. The measurements are based on three techniques: (i) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (ii) the direct measurement of halo currents into specially instrument tiles, and (iii) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peaking factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems is shown.
Liu, D., E-mail: deyongl@uci.edu; Heidbrink, W. W.; Zhu, Y. B. [Department of Physics and Astronomy, University of California - Irvine, Irvine, California 92697 (United States); Tritz, K. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Roquemore, A. L.; Medley, S. S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
2014-11-15T23:59:59.000Z
A new compact, multi-channel Solid State Neutral Particle Analyzer (SSNPA) diagnostic based on silicon photodiode array has been designed and is being fabricated for the National Spherical Torus Experiment-Upgrade (NSTX-U). The SSNPA system utilizes a set of vertically stacked photodiode arrays in current mode viewing the same plasma region with different filter thickness to obtain fast temporal resolution (?120 kHz bandwidth) and coarse energy information in three bands of >25?keV, >45 keV, and >65 keV. The SSNPA system consists of 15 radial sightlines that intersect existing on-axis neutral beams at major radii between 90 and 130 cm, 15 tangential sightlines that intersect new off-axis neutral beams at major radii between 120 and 145 cm. These two subsystems aim at separating the response of passing and trapped fast ions. In addition, one photodiode array whose viewing area does not intersect any neutral beams is used to monitor passive signals produced by fast ions that charge exchange with background neutrals.
Gerhardt, S. P.; Fredrickson, E.; Guttadora, L.; Kaita, R.; Kugel, H.; Menard, J. [Princeton Plasma Physics Laboratory, Plainsboro, New Jersey 08540 (United States); Takahashi, H. [Princeton Fusion Research LLC, Princeton, New Jersey 08540 (United States)
2011-10-15T23:59:59.000Z
This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments [M. Ono et al., Nucl. Fusion 40, 557 (2000)]. The measurements are based on three techniques: (1) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (2) the direct measurement of halo currents into specially instrument tiles, and (3) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peaking factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems are shown.
R.J. Maqueda, D.P. Stotler and the NSTX Team.
2010-05-19T23:59:59.000Z
While intermittent filamentary structures, also known as blobs, are routinely seen in the low-field-side scrape-off layer of the National Spherical Torus Experiment (NSTX) (Ono et al 2000 Nucl. Fusion 40 557), fine structured filaments are also seen on the lower divertor target plates of NSTX. These filaments, not associated with edge localized modes, correspond to the interaction of the turbulent blobs seen near the midplane with the divertor plasma facing components. The fluctuation level of the neutral lithium light observed at the divertor, and the skewness and kurtosis of its probability distribution function, is similar to that of midplane blobs seen in D?; e.g. increasing with increasing radii outside the outer strike point (OSP) (separatrix). In addition, their toroidal and radial movement agrees with the typical movement of midplane blobs. Furthermore, with the appropriate magnetic topology, i.e. mapping between the portion of the target plates being observed into the field of view of the midplane gas puff imaging diagnostic, very good correlation is observed between the blobs and the divertor filaments. The correlation between divertor plate filaments and midplane blobs is lost close to the OSP. This latter observation is consistent with the existence of ‘magnetic shear disconnection’ due to the lower X-point, as proposed by Cohen and Ryutov (1997 Nucl. Fusion 37 621).
Spherical torus fusion reactor
Martin Peng, Y.K.M.
1985-10-03T23:59:59.000Z
The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.
C.E. Bush; M.G. Bell; R.E. Bell; J. Boedo; E.D. Fredrickson; S.M. Kaye; S. Kubota; B.P. LeBlanc; R. Maingi; R.J. Maqueda; S.A. Sabbagh; V.A. Soukhanovskii; D. Stutman; D.W. Swain; J.B. Wilgen; S.J. Zweben; W.M. Davis; D.A. Gates; D.W. Johnson; R. Kaita; H.W. Kugel; D. Mastrovito; S. Medley; J.E. Menard; D. Mueller; M. Ono; F. Paoletti; S.J. Paul; Y-K.M. Peng; R. Raman; P.G. Roney; A.L. Roquemore; C.H. Skinner; E.J. Synakowski; G. Taylor; the NSTX Team
2003-01-09T23:59:59.000Z
Edge parameters play a critical role in H-mode (high-confinement mode) access, which is a key component of plasma discharge optimization in present-day toroidal confinement experiments and the design of next-generation devices. Because the edge magnetic topology of a spherical torus (ST) differs from a conventional aspect ratio tokamak, H-modes in STs exhibit important differences compared with tokamaks. The dependence of the NSTX (National Spherical Torus Experiment) edge plasma on heating power, including the L-H transition requirements and the occurrence of edge-localized modes (ELMs), and on divertor configuration is quantified. Comparisons between good L-modes (low-confinement modes) and H-modes show greater differences in the ion channel than the electron channel. The threshold power for the H-mode transition in NSTX is generally above the predictions of a recent ITER (International Thermonuclear Experimental Reactor) scaling. Correlations of transition and ELM phenomena with turbulent fluctuations revealed by Gas Puff Imaging (GPI) and reflectometry are observed. In both single-null and double-null divertor discharges, the density peaks off-axis, sometimes developing prominent ''ears'' which can be sustained for many energy confinement times, tau subscript ''E'', in the absence of ELMs. A wide variety of ELM behavior is observed, and ELM characteristics depend on configuration and fueling.
Bell, R E; Kaye, S M; Kolesnikov, R A; LeBlance, B P; Rewolldt, G; Wang, W X
2010-04-07T23:59:59.000Z
Knowledge of poloidal velocity is necessary for the determination of the radial electric field, Er, which along with its gradient is linked to turbulence suppression and transport barrier formation. Recent measurements of poloidal flow on conventional tokamaks have been reported to be an order of magnitude larger than expected from neoclassical theory. In contrast, recent poloidal velocity measurements on the NSTX spherical torus [S. M. Kaye et al., Phys. Plasmas 8, 1977 (2001)] are near or below neoclassical estimates. A novel charge exchange recombination spectroscopy diagnostic is used, which features active and passive sets of up/down symmetric views to produce line-integrated poloidal velocity measurements that do not need atomic physics corrections. Local profiles are obtained with an inversion. Poloidal velocity measurements are compared with neoclassical values computed with the codes NCLASS [W. A. Houlberg et al., Phys. Plasmas 4, 3230 (1997)] and GTC-Neo [W. X. Wang, et al., Phys. Plasmas 13, 082501 (2006)], which has been updated to handle impurities. __________________________________________________
Recent Progress on Spherical Torus Research
Ono, Masayuki [PPPL; Kaita, Robert [PPPL
2014-01-01T23:59:59.000Z
The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ~ 1.5, well below the normal tokamak operating range of A ? 2.5. As the aspect ratio is reduced, the ideal tokamak beta ? (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as ? ~ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation ?, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of attractive fusion energy power source. Since the start of the two megaampere class ST facilities in 2000, National Spherical Torus Experiment (NSTX) in the US and Mega Ampere Spherical Tokamak (MAST) in UK, active ST research has been conducted worldwide. More than sixteen ST research facilities operating during this period have achieved remarkable advances in all of fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.
Podesta, M; Fredrickson, E D; Gorelenkov, N N; LeBlanc, B P; Heidbrink, W W; Crocker, N A; Kubota, S
2010-08-19T23:59:59.000Z
The effects of a sheared toroidal rotation on the dynamics of bursting Toroidicity-induced Alfven eigenmodes are investigated in neutral beam heated plasmas on the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40 557 (2000)]. The modes have a global character, extending over most of the minor radius. A toroidal rotation shear layer is measured at the location of maximum drive for the modes. Contrary to results from other devices, no clear evidence of increased damping is found. Instead, experiments with simultaneous neutral beam and radio-frequency auxiliary heating show a strong correlation between the dynamics of the modes and the instability drive. It is argued that kinetic effects involving changes in the mode drive and damping mechanisms other than rotation shear, such as continuum damping, are mostly responsible for the bursting dynamics of the modes.
S.S. Medley; D.S. Darrow; A.L. Roquemore
2005-06-15T23:59:59.000Z
A change in the response of the neutron detectors on the National Spherical Torus Experiment occurred between the 2002-2003 and 2004 experimental run periods. An analysis of this behavior by investigating the neutron diagnostic operating conditions and comparing measured and TRANSP-calculated neutron rates is presented. Also a revised procedure for cross calibration of the neutron scintillator detectors with the fission chamber detectors was implemented that delivers good agreement amongst the measured neutron rates for all neutron detectors and all run periods. For L-mode discharges, the measured and TRANSP-calculated neutron rates now match closely for all run years. For H-mode discharges over the entire 2002-2004 period, the 2FG scintillator and fission chamber measurements match each other but imply a neutron deficit of 11.5% relative to the TRANSP-calculated neutron. The results of this report impose a modification on all of the previously used calibration factors for the entire neutron detector suite over the 2002-2004 period. A tabular summary of the new calibration factors is provided including certified calibration factors for the 2005 run.
Kaye, S. M., E-mail: skaye@pppl.gov; Guttenfelder, W.; Bell, R. E.; Gerhardt, S. P.; LeBlanc, B. P.; Maingi, R. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2014-08-15T23:59:59.000Z
A representative H-mode discharge from the National Spherical Torus eXperiment is studied in detail to utilize it as a basis for a time-evolving prediction of the electron temperature profile using an appropriate reduced transport model. The time evolution of characteristic plasma variables such as ?{sub e},??{sub e}{sup ?}, the MHD ? parameter, and the gradient scale lengths of T{sub e}, T{sub i}, and n{sub e} were examined as a prelude to performing linear gyrokinetic calculations to determine the fastest growing micro instability at various times and locations throughout the discharge. The inferences from the parameter evolutions and the linear stability calculations were consistent. Early in the discharge, when ?{sub e} and ?{sub e}{sup ?} were relatively low, ballooning parity modes were dominant. As time progressed and both ?{sub e} and ?{sub e}{sup ?} increased, microtearing became the dominant low-k{sub ?} mode, especially in the outer half of the plasma. There are instances in time and radius, however, where other modes, at higher-k{sub ?}, may, in addition to microtearing, be important for driving electron transport. Given these results, the Rebut-Lallia-Watkins (RLW) electron thermal diffusivity model, which is based on microtearing-induced transport, was used to predict the time-evolving electron temperature across most of the profile. The results indicate that RLW does a good job of predicting T{sub e} for times and locations where microtearing was determined to be important, but not as well when microtearing was predicted to be stable or subdominant.
Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J; Paul, S F; Raman, R; Roquemore, A L; Bell, R E; Bush, C; Kaita, R
2008-09-22T23:59:59.000Z
Experiments conducted in high-performance 1.0-1.2 MA 6 MW NBI-heated H-mode plasmas with a high flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub p} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the lower single null configuration with higher-end elongation 2.2-2.4 and triangularity 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using high magnetic flux expansion and partial detachment of the outer strike point at several D{sub 2} injection rates, while good core confinement and pedestal characteristics were maintained. The partially detached divertor regime was characterized by a 30-60% increase in divertor plasma radiation, a peak heat flux reduction by up to 70%, measured in a 10 cm radial zone, a five-fold increase in divertor neutral pressure, and a significant volume recombination rate increase.
Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J
2008-12-31T23:59:59.000Z
Experiments conducted in high-performance 1.0 MA and 1.2 MA 6 MW NBI-heated H-mode discharges with a high magnetic flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub t} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the strongly-shaped lower single null configuration with elongation {kappa} = 2.2-2.4 and triangularity {delta} = 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using the inherently high magnetic flux expansion f{sub m} = 16-25 and the partial detachment of the outer strike point at several D{sub 2} injection rates. A good core confinement and pedestal characteristics were maintained, while the core carbon concentration and the associated Z{sub eff} were reduced. The partially detached divertor regime was characterized by an increase in divertor radiated power, a reduction of ion flux to the plate, and a large neutral compression ratio. Spectroscopic measurements indicated a formation of a high-density, low temperature region adjacent to the outer strike point, where substantial increases in the volume recombination rate and CII, CIII emission rates was measured.
R.J. Maqueda, D.P. Stotler, S.J. Zweben, and the NSTX Team
2010-11-22T23:59:59.000Z
A gas puff imaging diagnostic is used in the National Spherical Tokamak Experiment [M. Ono, et al., Nucl. Fusion 40, 557 (2000)] to study the edge turbulence and intermittency present during H-mode discharges. In the case of low power Ohmic H-modes the suppression of turbulence/blobs is maintained through the duration of the (short lived) H-modes. Similar quiescent edges are seen during the early stages of H-modes created with the use of neutral beam injection. Nevertheless, as time progresses following the L-H transition, turbulence and blobs reappear although at a lower level than that typically seen during L-mode confinement. It is also seen that the time-averaged SOL emission profile broadens, as the power loss across the separatrix increases. These broad profiles are characterized by a large level of fluctuations and intermittent events.
Princeton Plasma Physics Laboratory
Demonstration of Tokamak Ohmic Flux Saving by Transient Coaxial Helicity Injection in the National in a significant Ohmic flux saving and produced equivalent quality tokamak plasmas. In addition, for the first time
Wang, Feng; Liu, J. Y. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Fu, G. Y.; Breslau, J. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Tritz, Kevin [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)
2013-07-15T23:59:59.000Z
Plasmas in spherical and conventional tokamaks, with weakly reversed shear q profile and minimum q above but close to unity, are susceptible to an non-resonant (m,n) = (1,1) internal kink mode. This mode can saturate and persist and can induce a (2,1) seed island for Neoclassical Tearing Mode. [Breslau et al. Nucl. Fusion 51, 063027 (2011)]. The mode can also lead to large energetic particle transport and significant broadening of beam-driven current. Motivated by these important effects, we have carried out extensive nonlinear simulations of the mode with finite toroidal rotation using parameters and profiles of an NTSX plasma with a weakly reversed shear profile. The numerical results show that, at the experimental level, plasma rotation has little effect on either equilibrium or linear stability. However, rotation can significantly influence the nonlinear dynamics of the (1,1) mode and the induced (2,1) magnetic island. The simulation results show that a rotating helical equilibrium is formed and maintained in the nonlinear phase at finite plasma rotation. In contrast, for non-rotating cases, the nonlinear evolution exhibits dynamic oscillations between a quasi-2D state and a helical state. Furthermore, the effects of rotation are found to greatly suppress the (2,1) magnetic island even at a low level.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sechrest, Y.; Munsat, T.; D’Ippolito, D. A.; Maqueda, R. J.; Myra, J. R.; Russell, D.; Zweben, S. J.
2011-01-01T23:59:59.000Z
Fluctuations in the edge and scrape-off layer (SOL) of L-mode plasmas in the National Spherical Torus Experiment (NSTX) as observed by the gas puff imaging (GPI) diagnostic are studied. Calculation of local, time resolved velocity maps using the Hybrid Optical Flow and Pattern Matching Velocimetry (HOP-V) code enables analysis of turbulent flow and shear behavior. Periodic reversals in the direction of the poloidal flow near the separatrix are observed. Also, poloidal velocities and their radial shearing rate are found to be well correlated with the fraction of D? light contained in the SOL, which acts as a measure of turbulentmore »bursts. The spectra of GPI intensity and poloidal velocity both have a strong feature near 3 kHz, which appears to correspond with turbulent bursts. This mode exhibits a poloidal structure with poloidal wavenumber of 7.7 m-1 for GPI intensity and 3.4 m-1 for poloidal velocity, and the poloidal velocity fluctuations near 3 kHz remain coherent over length scales in excess of the turbulent scales. Furthermore, recent SOL Turbulence (SOLT) simulations find a parameter regime that exhibits periodic bursty transport and shares many qualitative similarities with the experimental data. Strong correlations between the shearing rate and the turbulent bursts are observed for time periods of ~ 2 ms, but the relationship is complicated by several factors. Finally, measurements of the radial profiles of the Reynolds shear stresses are reported. These radial profiles exhibit many similarities for several shots, and a region with positive radial gradient is seen to be coincident with local flow shear.« less
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sechrest, Y. [Univ. of Colorado, Boulder, CO (United States); Munsat, T. [Univ. of Colorado, Boulder, CO (United States); D’Ippolito, D. A. [Lodestar Research Corp., Boulder, CO (United States); Maqueda, R. J. [Princeton Plasma Physics Lab., NJ (United States); Myra, J. R. [Lodestar Research Corp., Boulder, CO (United States); Russell, D. [Lodestar Research Corp., Boulder, CO (United States); Zweben, S. J. [Princeton Plasma Physics Lab., NJ (United States)
2011-01-10T23:59:59.000Z
Fluctuations in the edge and scrape-off layer (SOL) of L-mode plasmas in the National Spherical Torus Experiment (NSTX) [S. M. Kaye et al.,Phys. Plasmas 8, 1977 (2001)] as observed by the gas puff imaging (GPI) diagnostic are studied. Calculation of local, time resolved velocity maps using the Hybrid Optical Flow and Pattern Matching Velocimetry (HOP-V) code enables analysis of turbulent flow and shear behavior. Periodic reversals in the direction of the poloidal flow near the separatrix are observed. Also, poloidal velocities and their radial shearing rate are found to be well correlated with the fraction of D? light contained in the SOL, which acts as a measure of turbulent bursts. The spectra of GPI intensity and poloidal velocity both have a strong feature near 3 kHz, which appears to correspond with turbulent bursts. This mode exhibits a poloidal structure with poloidal wavenumber of 7.7 m-1 for GPI intensity and 3.4 m-1 for poloidal velocity, and the poloidal velocity fluctuations near 3 kHz remain coherent over length scales in excess of the turbulent scales. Furthermore, recent SOL Turbulence (SOLT) simulations find a parameter regime that exhibits periodic bursty transport and shares many qualitative similarities with the experimental data. Strong correlations between the shearing rate and the turbulent bursts are observed for time periods of ~ 2 ms, but the relationship is complicated by several factors. Finally, measurements of the radial profiles of the Reynolds shear stresses are reported. These radial profiles exhibit many similarities for several shots, and a region with positive radial gradient is seen to be coincident with local flow shear.
NATIONAL SPHERICAL TORUS CENTER STACK
Princeton Plasma Physics Laboratory
.................................. 2.4 Shear/Compression Tests ................................ INSULATION ELECTRICAL TESTS Conductor ............ 24 7.6 Winding Tension vs. Insulation Compression ......... 26 8.0 CONCLUSIONS SHEAR TESTS . . . 111 #12;INDEX OF TABLES 2-l 2-2 2-3 2-4 2-5 2-6 2-7 3-8 3-9 4-10 4-11 5-12 5-13 5-14 5
Abs t rac t ---The National Spherical Torus Experiment (NSTX) is a low aspect ratio s ph e r i c a l
, and initial power tests were completed in February o f 1 9 9 9 . The majority of the design and c on s t r u c. The Centerstack Assembly consists of the i nn e r legs of the Toroidal Field (TF) windings, t h e Ohmic Heating issues associated with the design, fabrication and assembly of the NSTX Torus system i nc l ud i ng those
Detection of Disruptions in the High-? Spherical Torus NSTX
Gerhardt, S P; Bell, R E; LeBlanc, B P; Menard, J E; Mueller, D; Roquemore, A L; Sabbagh, S A
2013-01-16T23:59:59.000Z
This paper describes the prediction of disruptions based on diagnostic data in the high-? spherical torus NSTX [M. Ono, et al., Nuclear Fusion 40 , 557 (2000)]. The disruptive threshold values on many signals are examined. In some cases, raw diagnostic data can be used as a signal for disruption prediction. In others, the deviations of the plasma data from simple models provides the signal used to determine the proximity to disruption. However, no single signal and threshold value can form the basis for disruption prediction in NSTX; thresholds that produce an acceptable false positive rate have too large a missed or late warning rate, while combinations that produce an acceptable rate of missed or late warnings have an unacceptable false positive rate. To solve this problem, a novel means of combining multiple threshold tests has been developed. After being properly tuned, this algorithm can produce a false positive rate of 2.8%, with a late warning rate of 3.7% when applied to a database of ~2000 disruptions collected from three run campaigns. Furthermore, many of these false positives are triggered by near-disruptive MHD events that might indeed be disruptive in larger plasmas with more stored energy. However, the algorithm is less efficient at detecting the MHD event that prompts the disruption process.
S. S. Medley, N. N. Gorelenkov, R. E. Bell, E. D. Fredrickson, S. P. Gerhardt, B. P. LeBlanc, M. Podestà, A. L. Roquemore, and the NSTX Team
2010-06-09T23:59:59.000Z
An increase of up to four-fold in the E||B Neutral Particle Analyzer (NPA) charge exchange neutral flux localized at the Neutral Beam (NB) injection full energy is observed in the National Spherical Torus Experiment (NSTX). Termed the High-Energy Feature (HEF), it appears on the NB-injected energetic ion spectrum only in discharges where tearing or kink-type modes (f < 10 kHz) are absent, TAE activity (f ~ 10-150 kHz) is weak (?Brms < 75 mGauss) and CAE/GAE activity (f ~ 400 – 1200 kHz) is robust. The feature exhibits a growth time of ~ 20 - 80 ms and occasionally develops a slowing down distribution that continues to evolve over periods of 100?s of milliseconds, a time scale long compared with the typical ~ 10?s ms equilibration time of the NB injected particles. The HEF is observed only in H-mode (not L-mode) discharges with injected NB power of 4 MW or greater and in the field pitch range v||/v ~ 0.7 – 0.9; i.e. only for passing (never trapped) energetic ions. The HEF is suppressed by vessel conditioning using lithium deposition at rates ~ 100 mg/shot, a level sufficient to suppress ELM activity. Increases of ~ 10 - 30 % in the measured neutron yield and total stored energy are observed to coincide with the feature along with broadening of measured Te(r), Ti(r) and ne(r) profiles. However, TRANSP analysis shows that such increases are driven by plasma profile changes and not the HEF phenomenon itself. Though a definitive mechanism has yet to be developed, the HEF appears to be caused by a form of TAE/CAE wave-particle interaction that distorts of the NB fast ion distribution in phase space.
An Inexpensive Ohmic Transformer Firing Circuit for the CDXU Spherical Torus
1 An Inexpensive Ohmic Transformer Firing Circuit for the CDXÂU Spherical Torus T. Munsat, R designed and modeled a simple, efficient circuit for delivering power to the CDXÂU ohmic transformer, spherical tori) have traditionally driven plasma current by using the transformer action of a centrally
An Inexpensive Ohmic Transformer Firing Circuit for the CDX-U Spherical Torus
1 An Inexpensive Ohmic Transformer Firing Circuit for the CDX-U Spherical Torus T. Munsat, R designed and modeled a simple, efficient circuit for delivering power to the CDX-U ohmic transformer, spherical tori) have traditionally driven plasma current by using the transformer action of a centrally
Review Closeout for the National Spherical Torus
Princeton Plasma Physics Laboratory
Questions 1. Critical Path Construction Efforts: Does the Project team have a realistic, executable schedule into critical path. Overall, 26 days were lost on critical path, but 24 days have been recovered in the schedule
Supported by National Spherical Torus Experiment
Transport? - Jenko, Doland,Hammet, PoP 8, 2001 JHU ETG's Role in ELM induced Cold Pulse S = - 0.3 kre ~ 0 Scaling, Electron Transport · Full set of diagnostics: including MSE for j(r) Unique Energetic Particle control coils on feedback performance #12;Significant Progress on Electron Heat Transport Physics
558: Calculation of Eddy Currents in the ETE Spherical Torus G.O. Ludwig
558: Calculation of Eddy Currents in the ETE Spherical Torus G.O. Ludwig Instituto Nacional de model based on the Green's function method. The distribution of eddy currents is calculated using a thin well with values of the eddy currents measured in ETE. INTRODUCTION This paper presents a magnetostatic
Physics basis for a spherical torus power plant S.C. Jardin a,
Najmabadi, Farrokh
Physics basis for a spherical torus power plant S.C. Jardin a, *, C.E. Kessel a , J. Menard a , T for a fusion power plant. A special class of wall-stabilized high-b high-bootstrap fraction low-aspect-ratio tokamak; Fusion power plant; Plasma operating regime 1. Introduction The most significant difference
Advanced tokamak reactors based on the spherical torus (ATR/ST). Preliminary design considerations
Miller, R.L.; Krakowski, R.A.; Bathke, C.G.; Copenhaver, C.; Schnurr, N.M.; Engelhardt, A.G.; Seed, T.J.; Zubrin, R.M.
1986-06-01T23:59:59.000Z
Preliminary design results relating to an advanced magnetic fusion reactor concept based on the high-beta, low-aspect-ratio, spherical-torus tokamak are summarized. The concept includes resistive (demountable) toroidal-field coils, magnetic-divertor impurity control, oscillating-field current drive, and a flowing liquid-metal breeding blanket. Results of parametric tradeoff studies, plasma engineering modeling, fusion-power-core mechanical design, neutronics analyses, and blanket thermalhydraulics studies are described. The approach, models, and interim results described here provide a basis for a more detailed design. Key issues quantified for the spherical-torus reactor center on the need for an efficient drive for this high-current (approx.40 MA) device as well as the economic desirability to increase the net electrical power from the nominal 500-MWe(net) value adopted for the baseline system. Although a direct extension of present tokamak scaling, the stablity and transport of this high-beta (approx.0.3) plasma is a key unknown that is resoluble only by experiment. The spherical torus generally provides a route to improved tokamak reactors as measured by considerably simplified coil technology in a configuration that allows a realistic magnetic divertor design, both leading to increased mass power density and reduced cost.
First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus
Gerhardt, S P; Canik, J M; Maingi, R; Bell, R; Gates, d; Goldston, R; Hawryluk, R; Le Blanc, B P; Menard, J; Sontag, A C; Sabbagh, S
2010-07-15T23:59:59.000Z
Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________
Berkery, J. W.; Sabbagh, S. A.; Balbaky, A. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B. P.; Manickam, J.; Menard, J. E.; Podestà, M. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)
2014-05-15T23:59:59.000Z
Global mode stability is studied in high-? National Spherical Torus Experiment (NSTX) plasmas to avoid disruptions. Dedicated experiments in NSTX using low frequency active magnetohydrodynamic spectroscopy of applied rotating n?=?1 magnetic fields revealed key dependencies of stability on plasma parameters. Observations from previous NSTX resistive wall mode (RWM) active control experiments and the wider NSTX disruption database indicated that the highest ?{sub N} plasmas were not the least stable. Significantly, here, stability was measured to increase at ?{sub N}?l{sub i} higher than the point where disruptions were found. This favorable behavior is shown to correlate with kinetic stability rotational resonances, and an experimentally determined range of measured E?×?B frequency with improved stability is identified. Stable plasmas appear to benefit further from reduced collisionality, in agreement with expectation from kinetic RWM stabilization theory, but low collisionality plasmas are also susceptible to sudden instability when kinetic profiles change.
PPPL-3445 PPPL-3445 National Spherical Torus Experiment (NSTX)
in Calendar Year 2000. The home page for PPPL Reports and Publications is: http://www.pppl.gov/pub_report/ DOE-term applications such as the Volume Neutron Source (VNS) and burning plasmas, and future applications to the plasma. The NBI heating system and associated NBI based diagnostics such as the CHERS will be operational
National Spherical Torus Experiment (NSTX) Center Stack Upgrade
Princeton Plasma Physics Laboratory
) coil surrounded by an ohmic heating (OH) solenoid and a several poloidal field (PF) shaping coils, all
M. Ono, NSTX 1 National Spherical Torus Experiment (NSTX)*
. The NBI heating system and associated NBI based diagnostics such as the CHERS will be operational in Oct.5, and plasma pulse length of up to 5 sec. The plasma heating / current drive (CD) tools are High Harmonic Fast device is shown in Fig. 1. The device midplane is about 3.5 m from the floor. The device center
National Spherical Torus Experiment NSTX CENTER STACK UPGRADE
Princeton Plasma Physics Laboratory
Analysis (FMEA) 14 2.6.3 Structural Design Criteria 15 2.7 Material Selection 15 2.8 General Electrical
National Spherical Torus Experiment NSTX CENTER STACK UPGRADE
Princeton Plasma Physics Laboratory
requirement; Changed "Machine Protection System (MPS) to "Digital Coil Protection (DCP) in various sections failure probability requirement; In 3.6 "Central Instrumentation and Control (I&C) System" added sections.6.2 Failure Modes and Effects Analysis (FMEA) 15 2.6.3 Structural Design Criteria 15 2.7 Material
National Spherical Torus Experiment Upgrade Status and Plans*
ANS 20th Topical Meeting on the Technology of Fusion Energy (TOFE-2012) Nashville, TN USA August 27 confinement physics predictive capability for ITER and beyond · Develop ST as fusion energy system Lithium fusion nuclear environment of copious neutrons to develop an experimental database on: Nuclear
National Spherical Torus Experiment (NSTX) Construction, Commissioning, and Initial Operations
supplies, and RF sources, cooling water systems, etc., is made to minimize the overall cost 350 C PFCs, 150C VV PROGRESS AND ACCOMPLISHMENTS Tremendous progress was made during the past year
National Spherical Torus Experiment (NSTX) Construction, Commissioning, and Initial Operations
magnet power supplies, and RF sources, cooling water systems, etc., is made to minimize the overall cost 350 C PFCs, 150C VV PROGRESS AND ACCOMPLISHMENTS Tremendous progress was made during the past year
Choe, Kyumin; Jung, Bongki [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)] [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of) [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)
2014-02-15T23:59:59.000Z
Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 × 120 × 120 mm{sup 3}), four helicon plasma injectors with annular permanent magnets and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.
in an underestimation of its cost and a more prolonged construction process. An 18-month series of project reviews spherical torus program Page 1 of 2http://www.princeton.edu/main/news/archive/S21/15/04A97/index://www.pppl.gov/> (PPPL) will phase out construction of the National Compact Stellarator Experiment (NCSX) and instead
Disruptions, Disruptivity, and Safer Operating Windows in the High-? Spherical Torus NSTX
Brown, T; Goldston, R J; El-Guebaly, L; Kessel, C; Neilson, G H; Malang, S; Menard, J E; Prager, S; Scott, S; Titus, P; Waganer, L
2012-09-26T23:59:59.000Z
A fusion pilot plant study was initiated to clarify the development needs in moving from ITER to a first of a kind fusion power plant. The mission of the pilot plant was set to encompass component test and fusion nuclear science missions yet produce net electricity with high availability in a device designed to be prototypical of the commercial device. The objective of the study was to evaluate three different magnetic configuration options, the advanced tokamak (AT), spherical tokamak (ST) and compact stellarator (CS) in an effort to establish component characteristics, maintenance features and the general arrangement of each candidate device. With the move to look beyond ITER the fusion community is now beginning to embark on DEMO reactor studies with an emphasis on defining configuration arrangements that can meet a high availability goal. This paper reviews the AT pilot plant design, detailing the selected maintenance approach, the device arrangement and sizing of the in-vessel components. Details of interfacing auxiliary systems and services that impact the ability to achieve high availability operations will also be discussed.
Fusion Power associates Annual Meeting and Symposium December 4-5, 2007 Oak Ridge Tennessee IEA ST Agreement technology U Wisc Ski Ch l Pl t i l i t ti PPPL Nuclear Technology IEA ST Agreement, FPCC, 2/27-28/07 2 100 IEA ST Agreement, FPCC, 2/27-28/07 3 Tritium self-sufficiency goal (%) ~0 ~100 100 # Abdou et al
Vessel Eddy Current Measurement for the National Spherical Torus Experiment (NSTX)
D.A. Gates; J. Menard; R. Marsala
2004-11-19T23:59:59.000Z
A simple analog circuit that measures the NSTX axisymmetric eddy current distribution has been designed and constructed. It is based on simple circuit model of the NSTX vacuum vessel that was calibrated using a special axisymmetric eddy current code which was written so that accuracy was maintained in the vicinity of the current filaments. The measurement and the model have been benchmarked against data from numerous vacuum shots and they are in excellent agreement. This is an important measurement that helps give more accurate equilibrium reconstructions.
Hammett, Greg
of Physics. Related Articles Hybrid-like 2/1 flux-pumping and magnetic island evolution due to edge localized in the presence of suffi- cient E Â B shear,14 which occurs in strongly beam heated plasmas. However
Confinement and Local Transport in the National Spherical Torus Experiment NSTX
Kaye, S M; Stutman, D; Tritz, K; Yuh, H; Bell, M G; Bell, R E; Domier, C W; Gates, D; Horton, W; Kim, J; LeBlanc, B P; Luhmann Jr, N C; Maingi, R; Mazzucato, E; Menard, J E; Mikkelsen, D; Mueller, D; Park, H; Rewoldt, G; Sabbagh, S A; Smith, D R
2007-03-15T23:59:59.000Z
NSTX operates at low aspect ratio (R/a~1.3) and high beta (up to 40%), allowing tests of global confinement and local transport properties that have been established from higher aspect ratio devices. NSTX plasmas are heated by up to 7 MW of deuterium neutral beams with preferential electron heating as expected for ITER. Confinement scaling studies indicate a strong ?? dependence, with a current dependence that is weaker than that observed at higher aspect ratio. Dimensionless scaling experiments indicate a strong increase of confinement with decreasing collisionality and a weak degradation with beta. The increase of confinement with ?? is due to reduced transport in the electron channel, while the improvement with plasma current is due to reduced transport in the ion channel related to the decrease in the neoclassical transport level. Improved electron confinement has been observed in plasmas with strong reversed magnetic shear, showing the existence of an electron internal transport barrier (eITB). The development of the eITB may be associated with a reduction in the growth of microtearing modes in the plasma core. Perturbative studies show that while L-mode plasmas with reversed magnetic shear and an eITB exhibit slow changes of L?e across the profile after the pellet injection, H-mode plasmas with a monotonic q-profile and no eITB show no change in this parameter after pellet injection, indicating the existence of a critical gradient that may be related to the q-profile. Both linear and non-linear simulations indicate the potential importance of ETG modes at the lowest ??. Localized measurements of high-? fluctuations exhibit a sharp decrease in signal amplitude levels across the L-H transition, associated with a decrease in both ion and electron transport, and a decrease in calculated linear microinstability growth rates across a wide ?-range, from the ITG/TEM regime up to the ETG regime.
National Spherical Torus Experiment (NSTX) | U.S. DOE Office of Science
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4
Physics Design of the National High-power Advanced Torus Experiment
Menard, J E; Fu, G -Y; Gorelenkov, N; Kaye, S M; Kramer, G; Maingi, R; Neumeyer, C L; Sabbagh, S A; Soukhanovskii, V A
2007-07-18T23:59:59.000Z
Moving beyond ITER toward a demonstration power reactor (Demo) will require the integration of stable high fusion gain in steady-state, advanced methods for dissipating very high divertor heat-fluxes, and adherence to strict limits on in-vessel tritium retention. While ITER will clearly address the issue of high fusion gain, and new and planned long-pulse experiments (EAST, JT60-SA, KSTAR, SST-1) will collectively address stable steady-state highperformance operation, none of these devices will adequately address the integrated heat-flux, tritium retention, and plasma performance requirements needed for extrapolation to Demo. Expressing power exhaust requirements in terms of Pheat/R, future ARIES reactors are projected to operate with 60-200MW/m, a Component Test Facility (CTF) or Fusion Development Facility (FDF) for nuclear component testing (NCT) with 40-50MW/m, and ITER 20-25MW/m. However, new and planned long-pulse experiments are currently projected to operate at values of Pheat/R no more than 16MW/m. Furthermore, none of the existing or planned experiments are capable of operating with very high temperature first-wall (Twall = 600-1000C) which may be critical for understanding and ultimately minimizing tritium retention with a reactor-relevant metallic first-wall. The considerable gap between present and near-term experiments and the performance needed for NCT and Demo motivates the development of the concept for a new experiment — the National High-power advanced-Torus eXperiment (NHTX) — whose mission is to study the integration of a fusion-relevant plasma-material interface with stable steady-state high-performance plasma operation.
Scientific Opportunities and Challenges in the Upgraded National Spherical
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside theFacebook Twitter YouTubeOffice of ScienceData Movement enabled by theTorus
Princeton Plasma Physics Laboratory
of shielded (for neutrons and x-rays) periscopes (e.g., as on JET1 , DIII-D15 ) or us- ing radiation
Boedo, J. A., E-mail: jboedo@ucsd.edu; Rudakov, D. L. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)] [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States); Myra, J. R.; D'Ippolito, D. A. [Lodestar Research Corp, 2400 Central Ave., Boulder, Colorado 80301 (United States)] [Lodestar Research Corp, 2400 Central Ave., Boulder, Colorado 80301 (United States); Zweben, S.; Maingi, R.; Maqueda, R. J.; Bell, R.; Kugel, H.; Leblanc, B.; Roquemore, L. A. [Princeton University, PO Box 451, Princeton, New Jersey 08543 (United States)] [Princeton University, PO Box 451, Princeton, New Jersey 08543 (United States); Soukhanovskii, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Ahn, J. W.; Canik, J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, Tennessee 37830 (United States)] [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, Tennessee 37830 (United States); Crocker, N. [University of California Los Angeles, PO Box 957099, Los Angeles, California 90095 (United States)] [University of California Los Angeles, PO Box 957099, Los Angeles, California 90095 (United States)
2014-04-15T23:59:59.000Z
Transport and turbulence profiles were directly evaluated using probes for the first time in the edge and scrape-off layer (SOL) of NSTX [Ono et al., Nucl. Fusion 40, 557 (2000)] in low (L) and high (H) confinement, low power (P{sub in}? 1.3?MW), beam-heated, lower single-null discharges. Radial turbulent particle fluxes peak near the last closed flux surface (LCFS) at ?4×10{sup 21}?s{sup ?1} in L-mode and are suppressed to ?0.2×10{sup 21}?s{sup ?1} in H mode (80%–90% lower) mostly due to a reduction in density fluctuation amplitude and of the phase between density and radial velocity fluctuations. The radial particle fluxes are consistent with particle inventory based on SOLPS fluid modeling. A strong intermittent component is identified. Hot, dense plasma filaments 4–10?cm in diameter, appear first ?2?cm inside the LCFS at a rate of ?1×10{sup 21}?s{sup ?1} and leave that region with radial speeds of ?3–5?km/s, decaying as they travel through the SOL, while voids travel inward toward the core. Profiles of normalized fluctuations feature levels of 10% inside LCFS to ?150% at the LCFS and SOL. Once properly normalized, the intermittency in NSTX falls in similar electrostatic instability regimes as seen in other devices. The L-H transition causes a drop in the intermittent filaments velocity, amplitude and number in the SOL, resulting in reduced outward transport away from the edge and a less dense SOL.
None
2013-08-27T23:59:59.000Z
The implementation of the liquid Lithium Divertor (LLD) in NSTX presented a unique opportunity in plasma-material interactions studies. A high density Langmuir Probe (HDLP) array utilizing a dense pack of triple Langmuir probes was built at PPPL and the electronics designed and built by UIUC. It was shown that the HDLP array could be used to characterize the modification of the EEDF during lithium experiments on NSTX as well as characterize the transient particle loads during lithium experiments as a means to study ELMs. With NSTX being upgraded and a new divertor being installed, the HDLP array will not be used in NSTX-U. However UIUC is currently helping to develop two new systems for depositing lithium into NSTX-U, a Liquid Lithium Pellet Dripper (LLPD) for use with the granular injector for ELM mitigation and control studies as well as an Upward-Facing Lithium Evaporator (U-LITER) based on a flash evaporation system using an electron beam. Currently UIUC has Daniel Andruczyk Stationed at PPPL and is developing these systems as well as being involved in preparing the Materials Analysis Particle Probe (MAPP) for use in LTX and NSTX-U. To date the MAPP preparations have been completed. New sample holders were designed by UIUC?s Research Engineer at PPPL and manufactured at PPPL and installed. MAPP is currently being used on LTX to do calibration and initial studies. The LLPD has demonstrated that it can produce pellets. There is still some adjustments needed to control the frequency and particle size. Equipment for the U-LITER has arrived and initial test are being made of the electron beam and design of the U-LITER in progress. It is expected to have these ready for the first run campaign of NSTX-U.
La Haye, R. J.; Buttery, R. J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Gerhardt, S. P. [Princeton Plasma Physics Laboratory, P.O. Box 451 Princeton, New Jersey 08543 (United States); Sabbagh, S. A. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Brennan, D. P. [University of Tulsa, 800 South Tucker Drive, Tulsa, Oklahoma 74104 (United States)
2012-06-15T23:59:59.000Z
Neoclassical tearing mode islands are sustained by helically perturbed bootstrap currents arising at finite beta from toroidal effects that trap a fraction of the particles in non-circulating orbits. DIII-D and NSTX are here operated with similar shape and cross-sectional area but almost a factor of two difference in inverse aspect ratio a/R. In these experiments, destabilized n=1 tearing modes were self-stabilized (reached the 'marginal point') by reducing neutral-beam power and thus beta. The measure of the marginal island gives information on the small-island stabilizing physics that in part (with seeding) governs onset. The marginal island width on NSTX is found to be about three times the ion banana width and agrees with that measured in DIII-D, except for DIII-D modes closer to the magnetic axis, which are about two times the ion banana width. There is a balance of the helically perturbed bootstrap term with small island effects with the sum of the classical and curvature terms in the modified Rutherford equation for tearing-mode stability at the experimental marginal point. Empirical evaluation of this sum indicates that while the stabilizing effect of the curvature term is negligible in DIII-D, it is important in NSTX. The mode temporal behavior from the start of neutral-beam injection reduction also suggests that NSTX operates closer to marginal classical tearing stability; this explains why there is little hysteresis in beta between mode onset, saturation, and self-stabilization (while DIII-D has large hysteresis in beta). NIMROD code module component calculations based on DIII-D and NSTX reconstructed experimental equilibria are used to diagnose and confirm the relative importance of the stabilizing curvature effect, an advantage for low aspect ratio; the relatively greater curvature effect makes for less susceptibility to NTM onset even if the classical tearing stability index is near marginal.
Simulation of High-Harmonic Fast-Wave Heating on the National Spherical Tokamak Experiment
Green, David L [ORNL; Jaeger, Erwin Frederick [ORNL; Chen, Guangye [ORNL; Berry, Lee A [ORNL; Pugmire, Dave [ORNL; Canik, John [ORNL; Ryan, Philip Michael [ORNL
2011-01-01T23:59:59.000Z
Images associated with radio-frequency heating of low-confinement mode plasmas in the National Spherical Tokamak Experiment, as calculated by computer simulation, are presented. The AORSA code has been extended to simulate the whole antenna-to-plasma heating system by including both the kinetic physics of the well-confined core plasma and a poorly confined scrape-off plasma and vacuum vessel structure. The images presented show the 3-D electric wave field amplitude for various antenna phasings. Visualization of the simulation results in 3-D makes clear that -30 degrees phasing excites kilo-volt per meter coaxial standing modes in the scrape-off plasma and shows magnetic-field-aligned whispering-gallery type modes localized to the plasma edge.
Spherical Torus (Spherical Tokamak) on the Path to Fusion Energy
USBPO-ITPA activities in preparation for burning plasma research in ITER using physics breadth provided and benefits from USBPO-ITPA in preparing for burning plasma research on ITER "Locked mode" threshold n
Princeton Plasma Physics Laboratory
a pulsed power load that would limit the lifetime of plasma-facing components (PFCs) unless the energyEdge-Localized-Mode Suppression through Density-Profile Modification with Lithium-Wall Coatings to low-n peeling or ballooning modes, while broader pressure profiles stabilized the post-Li discharges
The Columbia Non-neutral Torus
Thomas Sunn Pedersen
2009-09-23T23:59:59.000Z
Final report for the Columbia Non-neutral Torus. This details the results from the design, construction and initial operation of the Columbia Non-neutral Torus.
The Condensate from Torus Knots
A. Gorsky; A. Milekhin; N. Sopenko
2015-06-22T23:59:59.000Z
We discuss recently formulated instanton-torus knot duality in $\\Omega$-deformed 5D SQED on $\\mathbb{R}^4 \\times S^1$ focusing at the microscopic aspects of the condensate formation in the instanton ensemble. Using the chain of dualities and geometric transitions we embed the SQED with a surface defect into the $SU(2)$ SQCD with $N_f=4$ and identify the numbers $(n,m)$ of the torus $T_{n,m}$ knot as instanton charge and electric charge. The HOMFLY torus knot invariants in the fundamental representation provide entropic factor in the condensate of the massless flavor counting the degeneracy of the instanton--W-boson web with instanton and electric numbers $(n,m)$ but different spin and flavor content. Using the inverse geometrical transition we explain how our approach is related to the evaluation of the HOMFLY invariants in terms of Wilson loop in 3d CS theory. The reduction to 4D theory is briefly considered and some analogy with baryon vertex is conjectured.
Transition between Spherical RFP and Spherical Torus during the Helicity Injection Process
Washington at Seattle, University of
(major radius R = 0.30 m, minor radius a = 0.24 m, aspect ratio #12;22 Gas Puff Valves (4) Insulator, must pass through the m=1/n=1 rational barrier, i.e. the Kruskal-Shafranov limit. It is thus
N. Aizawa; R. Chakrabarti
2007-05-04T23:59:59.000Z
We note that the recently introduced fuzzy torus can be regarded as a q-deformed parafermion. Based on this picture, classification of the Hermitian representations of the fuzzy torus is carried out. The result involves Fock-type representations and new finite dimensional representations for q being a root of unity as well as already known finite dimensional ones.
Reactor assessments of advanced bumpy torus configurations
Uckan, N.A.; Owen, L.W.; Spong, D.A.; Miller, R.L.; Ard, W.B.; Pipkins, J.F.; Schmitt, R.J.
1983-01-01T23:59:59.000Z
Recently, several configurational approaches and concept improvement schemes were introduced for enhancing the performance of the basic ELMO Bumpy Torus (EBT) concept and for improving its reactor potential. These configurations include planar racetrack and square geometries, Andreoletti coil systems, and bumpy torus-stellarator hybrids (which include twisted racetrack and helical axis stellarator-snakey torus). Preliminary evaluations of reactor implications of each of these configurations have been carried out based on magnetics (vacuum) calculations, transport and scaling relationships, and stability properties. Results indicate favorable reactor projections with a significant reduction in reactor physical size as compared to conventional EBT reactor designs carried out in the past.
Energy Science and Technology Software Center (OSTI)
002440MLTPL00 3D Torus Routing Engine Module for OFA OpenSM v. 1.0 http://www.openfabrics.org/git?p=sashak/management.git;a=sum
Methanol in the L1551 Circumbinary Torus
Glenn J. White; C. W. M. Fridlund; P. Bergman; A. Beardsmore; Rene Liseau; R. R. Phillips
2006-09-25T23:59:59.000Z
We report observations of gaseous methanol in an edge-on torus surrounding the young stellar object L1551 IRS5. The peaks in the torus are separated by ~ 10,000 AU from L1551 IRS5, and contain ~ 0.03 earth masses of cold methanol. We infer that the methanol abundance increases in the outer part of the torus, probably as a result of methanol evaporation from dust grain surfaces heated by the shock luminosity associated with the shocks associated with the jets of an externally located x-ray source. Any methanol released in such a cold environment will rapidly freeze again, spreading methanol throughout the circumbinary torus to nascent dust grains, planitesimals, and primitive bodies. These observations probe the initial chemical conditions of matter infalling onto the disk.
Spherical Carbon with Unique Architectures and Properties
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Spherical Carbon with Unique Architectures and Properties V.G. Pol, K.C. Lau, L.A. Curtiss, J.G. Wen, D.J. Miller, and M.M. Thackeray, Argonne National Laboratory Carbon atoms can...
Zero point energy on extra dimension: Noncommutative Torus
S. Fabi; B. Harms; G. Karatheodoris
2007-04-25T23:59:59.000Z
In this paper we calculate the zero point energy density experienced by observers on M^4 due to a massless scalar field defined throughout M^4 x T^2_F, where T^2_F are fuzzy extra dimensions. Using the Green's function approach we calculate the energy density for the commutative torus and the fuzzy torus. We calculate then the energy density for the fuzzy torus using the Hamiltonian approach. Agreement is shown between Green's function and Hamiltonian approaches.
FY 2006 Miniature Spherical Retroreflectors Final Report
Anheier, Norman C.; Bernacki, Bruce E.; Krishnaswami, Kannan
2006-12-28T23:59:59.000Z
Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniature spherical retroreflectors using the unique optical and material properties of chalcogenide glass to reduce both performance limiting spherical aberrations. The optimized optical performance will provide efficient signal retroreflection that enables a broad range of remote detection scenarios for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications. Miniature spherical retroreflectors can be developed to aid in the detection of signatures of nuclear proliferation or other chemical vapor or radiation signatures. Miniature spherical retroreflectors are not only well suited to traditional LIDAR methods for chemical plume detection and identification, but could enable remote detection of difficult semi-volatile chemical materials or low level radiation sources.
Leung, Ka-Ngo
2006-11-21T23:59:59.000Z
A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.
Global Bifurcation Destroying The Experimental Torus T2
T. Pereira; M. S. Baptista; M. B. Reyes; I. L. Caldas; J. C. Sartorelli; J. Kurths
2007-06-22T23:59:59.000Z
We show experimentally the scenario of a two-frequency torus $T^2$ breakdown, in which a global bifurcation occurs due to the collision of a torus with an unstable periodic orbit, creating a heteroclinic saddle connection, followed by an intermittent behavior.
RADON TRANSFORM ON THE TORUS AHMED ABOUELAZ AND FRANOIS ROUVIRE
Vallette, Bruno
RADON TRANSFORM ON THE TORUS AHMED ABOUELAZ AND FRANÇOIS ROUVIÈRE Abstract. We consider the Radon-Ricci spaces etc. We consider here the n-dimensional (at) torus Tn = Rn=Zn and the Radon transform de will thus enter the picture, as in the case of Radon transforms on Zn already studied by the ...rst author
Magnetic surfaces in an axisymmetric torus
Skovoroda, A. A., E-mail: skovorod@nfi.kiae.ru [National Research Centre Kurchatov Institute (Russian Federation)
2013-04-15T23:59:59.000Z
A method is developed for specifying the boundary equilibrium magnetic surface in an axially symmetric torus by using the absolute values of the magnetic field B = B{sub s}({theta}) and the gradient of the poloidal flux vertical bar vertical bar {nabla}{Psi} vertical bar = vertical bar {nabla}{Psi} vertical bar {sub s}({theta}) in a special flux coordinate system. By setting two surface constants (e.g., the safety factor q and dp/d{Psi}) and matching the absolute values of the magnetic field and the flux gradient on a closed magnetic surface, it is possible to find all equilibrium magnetic functions (including n {center_dot} {nabla} ln B and the local shear s) and all constants (including the toroidal current J and the shear d{mu}/d{Psi}) on this surface. Such a non-traditional formulation of the boundary conditions in solving the stability problem in an axisymmetric torus allows one to impose intentional conditions on plasma confinement and MHD stability at the periphery of the system.
Arithmetic functions in torus and tree networks
Bhanot, Gyan (Princeton, NJ); Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton On Hudson, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Steinmacher-Burow, Burkhard D. (Mount Kisco, NY); Vranas, Pavlos M. (Bedford Hills, NY)
2007-12-25T23:59:59.000Z
Methods and systems for performing arithmetic functions. In accordance with a first aspect of the invention, methods and apparatus are provided, working in conjunction of software algorithms and hardware implementation of class network routing, to achieve a very significant reduction in the time required for global arithmetic operation on the torus. Therefore, it leads to greater scalability of applications running on large parallel machines. The invention involves three steps in improving the efficiency and accuracy of global operations: (1) Ensuring, when necessary, that all the nodes do the global operation on the data in the same order and so obtain a unique answer, independent of roundoff error; (2) Using the topology of the torus to minimize the number of hops and the bidirectional capabilities of the network to reduce the number of time steps in the data transfer operation to an absolute minimum; and (3) Using class function routing to reduce latency in the data transfer. With the method of this invention, every single element is injected into the network only once and it will be stored and forwarded without any further software overhead. In accordance with a second aspect of the invention, methods and systems are provided to efficiently implement global arithmetic operations on a network that supports the global combining operations. The latency of doing such global operations are greatly reduced by using these methods.
Saturn in hot water: viscous evolution of the Enceladus torus
Alison J. Farmer
2008-06-09T23:59:59.000Z
The detection of outgassing water vapor from Enceladus is one of the great breakthroughs of the Cassini mission. The fate of this water once ionized has been widely studied; here we investigate the effects of purely neutral-neutral interactions within the Enceladus torus. We find that, thanks in part to the polar nature of the water molecule, a cold (~180 K) neutral torus would undergo rapid viscous heating and spread to the extent of the observed hydroxyl cloud, before plasma effects become important. We investigate the physics behind the spreading of the torus, paying particular attention to the competition between heating and rotational line cooling. A steady-state torus model is constructed, and it is demonstrated that the torus will be observable in the millimeter band with the upcoming Herschel satellite. The relative strength of rotational lines could be used to distinguish between physical models for the neutral cloud.
Recent progress on spherical torus research (Journal Article) | SciTech
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect JournalPentoxide.Conference: Radiative Penguin Decayssolids(Conference)
Progress in Understanding Error-field Physics in NSTX Spherical Torus Plasmas
E. Menard, R.E. Bell, D.A. Gates, S.P. Gerhardt, J.-K. Park, S.A. Sabbagh, J.W. Berkery, A. Egan, J. Kallman, S.M. Kaye, B. LeBlanc, Y.Q. Liu, A. Sontag, D. Swanson, H. Yuh, W. Zhu and the NSTX Research Team
2010-05-19T23:59:59.000Z
The low aspect ratio, low magnetic field, and wide range of plasma beta of NSTX plasmas provide new insight into the origins and effects of magnetic field errors. An extensive array of magnetic sensors has been used to analyze error fields, to measure error field amplification, and to detect resistive wall modes in real time. The measured normalized error-field threshold for the onset of locked modes shows a linear scaling with plasma density, a weak to inverse dependence on toroidal field, and a positive scaling with magnetic shear. These results extrapolate to a favorable error field threshold for ITER. For these low-beta locked-mode plasmas, perturbed equilibrium calculations find that the plasma response must be included to explain the empirically determined optimal correction of NSTX error fields. In high-beta NSTX plasmas exceeding the n=1 no-wall stability limit where the RWM is stabilized by plasma rotation, active suppression of n=1 amplified error fields and the correction of recently discovered intrinsic n=3 error fields have led to sustained high rotation and record durations free of low-frequency core MHD activity. For sustained rotational stabilization of the n=1 RWM, both the rotation threshold and magnitude of the amplification are important. At fixed normalized dissipation, kinetic damping models predict rotation thresholds for RWM stabilization to scale nearly linearly with particle orbit frequency. Studies for NSTX find that orbit frequencies computed in general geometry can deviate significantly from those computed in the high aspect ratio and circular plasma cross-section limit, and these differences can strongly influence the predicted RWM stability. The measured and predicted RWM stability is found to be very sensitive to the E × B rotation profile near the plasma edge, and the measured critical rotation for the RWM is approximately a factor of two higher than predicted by the MARS-F code using the semi-kinetic damping model.
Ohmic Flux Consumption During Initial Operation of the NSTX Spherical Torus
been achieved on NSTX, while faster ramps generate significant MHD activity. Discharges with IP will rely on OH current drive to generate target plasmas suitable for strong auxiliary heating to test.5, vacuum toroidal field B T = 0.3 Tesla at R 0 , plasma current I P
Large displacement spherical joint
Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)
2002-01-01T23:59:59.000Z
A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.
Torus CLAS12-Superconducting Magnet Quench Analysis
Kashikhin, V S; Elouadhiri, L; Ghoshal, P K; Kashy, D; Makarov, A; Pastor, O; Quettier, L; Velev, G; Wiseman, M
2014-06-01T23:59:59.000Z
The JLAB Torus magnet system consists of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration. These coils are wound with SSC-36 Nb-Ti superconductor and have the peak magnetic field of 3.6 T. The first coil manufacturing based on the JLAB design began at FNAL. The large magnet system dimensions (8 m diameter and 14 MJ of stored energy) dictate the need for quench protection. Each coil is placed in an aluminum case mounted inside a cryostat and cooled by 4.6 K supercritical helium gas flowing through a copper tube attached to the coil ID. The large coil dimensions and small cryostat thickness drove the design to challenging technical solutions, suggesting that Lorentz forces due to transport currents and eddy currents during quench and various failure scenarios are analyzed. The paper covers the magnet system quench analysis using the OPERA3d Quench code.
From Use Cases of the Joint European Torus towards Integrated Commissioning Requirements of the ITER Tokamak
Zero point energy on extra dimensions: Noncommutative torus
Fabi, S.; Harms, B.; Karatheodoris, G. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, Alabama 35487-0324 (United States)
2007-09-15T23:59:59.000Z
In this paper we calculate the zero point energy density experienced by observers on M{sup 4} due to a massless scalar field defined throughout M{sup 4}xT{sub F}{sup 2}, where T{sub F}{sup 2} are fuzzy extra dimensions. Using the Green's function approach we calculate the energy density for the commutative torus and the fuzzy torus. We also calculate the energy density for the fuzzy torus using the Hamiltonian approach. Agreement is shown between the Green's function and Hamiltonian approaches.
Efficient Subtorus Processor Allocation in a Multi-Dimensional Torus
Weizhen Mao; Jie Chen; William Watson
2005-11-30T23:59:59.000Z
Processor allocation in a mesh or torus connected multicomputer system with up to three dimensions is a hard problem that has received some research attention in the past decade. With the recent deployment of multicomputer systems with a torus topology of dimensions higher than three, which are used to solve complex problems arising in scientific computing, it becomes imminent to study the problem of allocating processors of the configuration of a torus in a multi-dimensional torus connected system. In this paper, we first define the concept of a semitorus. We present two partition schemes, the Equal Partition (EP) and the Non-Equal Partition (NEP), that partition a multi-dimensional semitorus into a set of sub-semitori. We then propose two processor allocation algorithms based on these partition schemes. We evaluate our algorithms by incorporating them in commonly used FCFS and backfilling scheduling policies and conducting simulation using workload traces from the Parallel Workloads Archive. Specifically, our simulation experiments compare four algorithm combinations, FCFS/EP, FCFS/NEP, backfilling/EP, and backfilling/NEP, for two existing multi-dimensional torus connected systems. The simulation results show that our algorithms (especially the backfilling/NEP combination) are capable of producing schedules with system utilization and mean job bounded slowdowns comparable to those in a fully connected multicomputer.
SPHERICALLY-ACTUATED PLATFORM MANIPULATOR
Williams II, Robert L.
1 SPHERICALLY-ACTUATED PLATFORM MANIPULATOR Robert L. Williams II Dana B. Poling Ohio University://www.ent.ohiou.edu/~bobw #12;2 SPHERICALLY-ACTUATED PLATFORM MANIPULATOR Robert L. Williams II and Dana B. Poling Ohio University Athens, OH 45701 KEYWORDS: Spherical Actuation, Platform Manipulator, Parallel Robot ABSTRACT
Hollow spherical shell manufacture
O'Holleran, T.P.
1991-11-26T23:59:59.000Z
A process is disclosed for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry. 3 figures.
Hollow spherical shell manufacture
O'Holleran, Thomas P. (Belleville, MI)
1991-01-01T23:59:59.000Z
A process for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry.
Cascade of torus doubling bifurcations in a detuned laser
Krents, A A [S.P. Korolev Samara State Aerospace University, Samara (Russian Federation); Molevich, N E [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation)
2009-08-31T23:59:59.000Z
By using a simplified system of Maxwell-Bloch equations (with the adiabatically excluded polarisation of the medium), we studied the processes proceeding in the cross section of a light wave propagating in a wide-aperture laser emitting at the frequency detuned from the transition-line centre. It is shown that in the model under study the passage to the chaotic regime during a change in the wave propagation velocity across the aperture occurs via the doubling bifurcations of an ergodic two-dimensional torus. The spectrum of Lyapunov exponents is found and it is established that at bifurcation points a structurally unstable three-dimensional torus is produced, which gives rise to a stable doubled ergodic torus. (nonlinear optical phenomena)
Maass Cusp Forms on Singly Punctured Two-Torus
Siddig, Abubaker Ahmed Mohamed [Laboratory of Computational Sciences and Informatics, Institute for Mathematical Research Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Shah, Nurisya Mohd [Theoretical Physics Group, Department of Physics, Faculty of Science Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zainuddin, Hishamuddin [Laboratory of Computational Sciences and Informatics, Institute for Mathematical Research Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Theoretical Physics Group, Department of Physics, Faculty of Science Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)
2009-07-07T23:59:59.000Z
Quantum mechanical systems on punctured surfaces modeled by hyperbolic spaces can play an interesting role in exploring quantum chaos and in studying behaviour of future quantum nano-devices. The case of singly-punctured two-torus, for example, has been well-studied in the literature particularly for its scattering states. However, the bound states on the punctured torus given by Maass cusp forms are lesser known. In this note, we report on the algorithm of numerically computing these functions and we present ten lower-lying eigenvalues for each odd and even Maass cusp forms.
Admissibility condition and nontrivial indices on a noncommutative torus
Nagao, Keiichi [Theoretical Physics Laboratory, College of Education, Ibaraki University, Mito 310-8512 (Japan)
2006-03-15T23:59:59.000Z
We study the index of the Ginsparg-Wilson Dirac operator on a noncommutative torus numerically. To do this, we first formulate an admissibility condition which suppresses the fluctuation of gauge fields. Assuming this condition, we generate gauge configurations randomly, and find various configurations with nontrivial indices. We show one example of configurations with index 1 explicitly. This result provides the first evidence that nontrivial indices can be naturally defined on the noncommutative torus by utilizing the Ginsparg-Wilson relation and the admissibility condition.
Double slotted socket spherical joint
Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)
2001-05-22T23:59:59.000Z
A new class of spherical joints is disclosed. These spherical joints are capable of extremely large angular displacements (full cone angles in excess of 270.degree.), while exhibiting no singularities or dead spots in their range of motion. These joints can improve or simplify a wide range of mechanical devices.
The Gauss-Bonnet Theorem for the noncommutative two torus
Connes, Alain
2009-01-01T23:59:59.000Z
In this paper we show that the value at zero of the zeta function of the Laplacian on the non-commutative two torus, endowed with its canonical conformal structure, is independent of the choice of the volume element (Weyl factor) given by a (non-unimodular) state. We had obtained, in the late eighties, in an unpublished computation, a general formula for this value at zero involving modified logarithms of the modular operator of the state. We give here the detailed computation and prove that the result is independent of the Weyl factor as in the classical case, thus proving the analogue of the Gauss-Bonnet theorem for the noncommutative two torus.
Spherically symmetric cosmology: resource paper
A. A. Coley; W. C. Lim; G. Leon
2008-03-06T23:59:59.000Z
We use the 1+3 frame formalism to write down the evolution equations for spherically symmetric models as a well-posed system of first order PDEs in two variables, suitable for numerical and qualitative analysis.
facility, the National Spherical Torus Experiment, came into operation in 1999, ahead of schedule reaction possible. · Materials and by-products unsuitable for weapons production. · Radiological hazards
PPPL data may play role in first NASA space probe dedicated to...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the universe's physical processes. And since reconnection can also take place in, and drain energy from, fusion plasmas such those in PPPL's National Spherical Torus Experiment,...
Associate Research Physicist (Post Doc, Experimental Research...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Spherical Torus Experiment Upgrade (NSTX-U). For present and future magnetic fusion devices to operate reliably a high plasma pressure and high power density for...
Major Milestone: PPPL completes first quadrant of the heart of...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Major Milestone: PPPL completes first quadrant of the heart of the National Spherical Torus Experiment Upgrade By John Greenwald March 18, 2013 Tweet Widget Google Plus One Share...
Milking the spherical cow: on aspherical dynamics in spherical coordinates
Pontzen, Andrew; Teyssier, Romain; Governato, Fabio; Gualandris, Alessia; Roth, Nina; Devriendt, Julien
2015-01-01T23:59:59.000Z
Galaxies and the dark matter halos that host them are not spherically symmetric, yet spherical symmetry is a helpful simplifying approximation for idealised calculations and analysis of observational data. The assumption leads to an exact conservation of angular momentum for every particle, making the dynamics unrealistic. But how much does that inaccuracy matter in practice for analyses of stellar distribution functions, collisionless relaxation, or dark matter core-creation? We provide a general answer to this question for a wide class of aspherical systems; specifically, we consider distribution functions that are "maximally stable", i.e. that do not evolve at first order when external potentials (which arise from baryons, large scale tidal fields or infalling substructure) are applied. We show that a spherically-symmetric analysis of such systems gives rise to the false conclusion that the density of particles in phase space is ergodic (a function of energy alone). Using this idea we are able to demonstra...
Ashtekar Formulation of 2+1 Gravity on a Torus
N. Manojlovic; A. Mikovic
1992-04-09T23:59:59.000Z
Pure (2+1)-dimensional Einstein gravity is analysed in the Ashtekar formulation, when the spatial manifold is a torus. We have found a set of globally defined observables, forming a closed algebra. This allowed us to solve the quantum constraints, and to show that the reduced phase space of the Ashtekar formulation is greater then the corresponding space of the Witten formulation. Furthermore, we have found a globally defined time variable which satisfies all the requiriments of an extrinsic time variable in quantum gravity.
FPA Meeting, 10/11-12/05 Status of World ST Research Status of World Spherical Torus Research
and Energy Policy October 11-12, 2005, Washington, DC Supported by Office of Science College W&M Colorado Sch Has a Tradition of Strong Collaboration · Active bilateral exchanges UK-US on NSTX and MAST START options for economical fusion reactor Phase III Target Strategy of the All-Japan ST Research Program (Prof
Washington at Seattle, University of
chamber for confine- ment and sustainment, which offers engineering advan- tages for a fusion reactor and confinement considera- tions, multipole fields are highly undesirable; the steady magnetic fields should at the end magnetic mirrors of the confinement chamber, the plasmoid relaxes into a pre- ferred near
Egedal, Jan
Calibration of the Joint European Torus energetic ion and alpha particle collective Thomson is calibrated assuming blackbody emission from the torus vacuum vessel ~VV! and using electron cyclotron emission ~ECE!. The 32 receiver channels are absolutely calibrated with a mechanical chopper
Egedal, Jan
Calibration of the Joint European Torus energetic ion and alpha particle collective Thomson Torus JET energetic ion and alpha particle collective Thomson scattering diagnostic is calibrated . The 32 receiver channels are absolutely calibrated with a mechanical chopper in the quasioptical arm
Fast waves and electron current drive in the Irvine Torus
Platt, R.C.
1987-01-01T23:59:59.000Z
This work reports the results of experimental studies of the fast wave with frequencies near the mean gyro-frequency in magnetized, toroidal plasmas with comparison to theory. Experiment investigating fast-wave dispersion and damping, and the use of unidirectional fast waves to drive steady-state electron currents were performed on the Irvine Torus. The wave was excited in the plasmas by a phased array antenna which allowed launching of uni- or bi-directional fast waves around the torus. Probe measurements of the angle of propagation of wave energy, radial wavelengths, and the direction and magnitude of radial wave phase velocities were found to be in good agreement with predictions from cold plasma theory. Measurements of fast-wave damping showed the observed damping lengths to be anomalously short when compared to predictions for electron Landau damping, transit-time magnetic pumping, and collisional damping, but may be explained by effects due to fast-wave scattering from drift-wave density fluctuations. Steady-state electron currents were driven by unidirectional fast waves. Up to 14% of the wave energy was converted to poloidal magnetic field energy. The maximum current observed was found to be in rough agreement with a prediction from quasi-linear theory.
Low-Recycling Conditions and Improved Core Confinement in Steady-State Operation Scenarios in JET (Joint European Torus)
Deuterium Beam Acceleration with 3rd Harmonic ICRH in Joint European Torus: Sawtooth Stabilization and Alfvén Eigenmodes
spherical harmonics for l < 20
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, J. Robert [Middle Tennessee State University; Volkov, Anatoliy [Middle Tennessee State University
2015-01-23T23:59:59.000Z
The widely used pseudoatom formalism [Stewart (1976). Acta Cryst. A32, 565–574; Hansen & Coppens (1978). Acta Cryst. A34, 909–921] in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the densitynormalized Cartesian spherical harmonic functions for up to l 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens [Acta Cryst. (1988), A44, 6–7]. It was shown that the analytical form for normalization coefficients is available primarily for l 4 [Hansen & Coppens, 1978; Paturle & Coppens, 1988; Coppens (1992). International Tables for Crystallography, Vol. B, Reciprocal space, 1st ed., edited by U. Shmueli, ch. 1.2. Dordrecht: Kluwer Academic Publishers; Coppens (1997). X-ray Charge Densities and Chemical Bonding. New York: Oxford University Press]. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens (Paturle & Coppens, 1988) method in the Wolfram Mathematica software to derive the Cartesian spherical harmonics for l 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.
efficient spectral-galerkin methods iv. spherical geometries
1999-10-21T23:59:59.000Z
numerical weather prediction. The most natural way to deal with spherical geometries is to use spherical coordi- nates and spherical harmonic functions.
Exponential Time Decay Estimates for the Landau Equation on Torus
Kung-Chien Wu
2013-01-04T23:59:59.000Z
We study the time decay estimates for the linearized Landau equation on torus when the initial perturbation is not necessarily smooth. Our result reveals the kinetic and fluid aspects of the equation. We design a Picard-type iteration and Mixture lemma for constructing the increasingly regular kinetic like waves, they are carried by transport equations and have exponential time decay rate. The fluid like waves are constructed as part of the long-wave expansion in the spectrum of the Fourier mode for the space variable and the time decay rate depends on the size of the domain. The Mixture lemma plays an important role in this paper, this lemma is parallel to Boltzmann equation but the proof is more challenge.
Pointwise Behavior of the Linearized Boltzmann Equation on Torus
Kung-Chien Wu
2013-01-04T23:59:59.000Z
We study the pointwise behavior of the linearized Boltzmann equation on torus for non-smooth initial perturbation. The result reveals both the fluid and kinetic aspects of this model. The fluid-like waves are constructed as part of the long-wave expansion in the spectrum of the Fourier mode for the space variable, the time decay rate of the fluid-like waves depends on the size of the domain. We design a Picard-type iteration for constructing the increasingly regular kinetic-like waves, which are carried by the transport equations and have exponential time decay rate. Moreover, the mixture lemma plays an important role in constructing the kinetic-like waves, we supply a new proof of this lemma to avoid constructing explicit solution of the damped transport equations
Low energy ion distribution measurements in Madison Symmetric Torus plasmas
Titus, J. B., E-mail: jtitus@cepast.famu.edu; Mezonlin, E. D. [Florida A and M University, Tallahassee, Florida 32310 (United States); Johnson, J. A. [Pyramid Plasmas LLC, Lawrenceville, Georgia 30043 (United States)
2014-06-15T23:59:59.000Z
Charge-exchange neutrals contain information about the contents of a plasma and can be detected as they escape confinement. The Florida A and M University compact neutral particle analyzer (CNPA), used to measure the contents of neutral particle flux, has been reconfigured, calibrated, and installed on the Madison Symmetric Torus (MST) for high temperature deuterium plasmas. The energy range of the CNPA has been extended to cover 0.34–5.2?keV through an upgrade of the 25 detection channels. The CNPA has been used on all types of MST plasmas at a rate of 20?kHz throughout the entire discharge (?70?ms). Plasma parameter scans show that the ion distribution is most dependent on the plasma current. Magnetic reconnection events throughout these scans produce stronger poloidal electric fields, stronger global magnetic modes, and larger changes in magnetic energy all of which heavily influence the non-Maxwellian part of the ion distribution (the fast ion tail)
Browning, P K; Evans, M; Lucini, F Arese; Lukin, V S; McClements, K G; Stanier, A
2015-01-01T23:59:59.000Z
Twisted magnetic flux ropes are ubiquitous in space and laboratory plasmas, and the merging of such flux ropes through magnetic reconnection is an important mechanism for restructuring magnetic fields and releasing free magnetic energy. The merging-compression scenario is one possible start up scheme for spherical tokamaks, which has been used on the Mega Amp Spherical Tokamak MAST. Two current-carrying plasma rings, or flux ropes, approach each other through the mutual attraction of their like currents, and merge, through magnetic reconnection, into a single plasma torus, with substantial plasma heating. 2D resistive MHD and Hall MHD simulations of this process are reported, and new results for the temperature distribution of ions and electrons are presented. A model of the based on relaxation theory is also described, which is now extended to tight aspect ratio geometry. This model allows prediction of the final merged state and the heating. The implications of the relaxation model for heating of the solar ...
Charged particle driver for ICF using an accelerated, focused compact torus
Meeker, D.J.; Hammer, J.H.; Hartman, C.W.
1986-06-01T23:59:59.000Z
We report the status of evaluating an accelerated and focused compact torus as a driver for ICF. We are studying the acceleration and focusing aspects experimentally in the RACE facility, a recently completed ring generator coupled to a 260 kJ acceleration bank. Compact torus and ICF target interaction is being investigated with PIC codes and LASNEX, a 2D magneto-hydrodynamics code. Final conditions required of the CT are discussed as well as coupling issues such as superthermal electron production. We conclude with an economic evaluation of a few 100 MW reactor driven by a compact torus. 9 refs., 5 figs., 1 tab.
Zhang, J.; Wang, Y. H.; Wang, D. Z. [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)
2013-08-15T23:59:59.000Z
Understanding the routes to chaos occurring in atmospheric-pressure dielectric barrier discharge systems by changing controlling parameters is very important to predict and control the dynamical behaviors. In this paper, a route of a quasiperiodic torus to chaos via the strange nonchaotic attractor is observed in an atmospheric-pressure dielectric barrier discharge driven by triangle-wave voltage. By increasing the driving frequency, the discharge system first bifurcates to a quasiperiodic torus from a stable single periodic state, and then torus and phase-locking periodic state appear and disappear alternately. In the meantime, the torus becomes increasingly wrinkling and stretching, and gradually approaches a fractal structure with the nonpositive largest Lyapunov exponent, i.e., a strange nonchaotic attractor. After that, the discharge system enters into chaotic state. If the driving frequency is further increased, another well known route of period-doubling bifurcation to chaos is also observed.
MODELING RESULTS FROM CESIUM ION EXCHANGE PROCESSING WITH SPHERICAL RESINS
Nash, C.; Hang, T.; Aleman, S.
2011-01-03T23:59:59.000Z
Ion exchange modeling was conducted at the Savannah River National Laboratory to compare the performance of two organic resins in support of Small Column Ion Exchange (SCIX). In-tank ion exchange (IX) columns are being considered for cesium removal at Hanford and the Savannah River Site (SRS). The spherical forms of resorcinol formaldehyde ion exchange resin (sRF) as well as a hypothetical spherical SuperLig{reg_sign} 644 (SL644) are evaluated for decontamination of dissolved saltcake wastes (supernates). Both SuperLig{reg_sign} and resorcinol formaldehyde resin beds can exhibit hydraulic problems in their granular (nonspherical) forms. SRS waste is generally lower in potassium and organic components than Hanford waste. Using VERSE-LC Version 7.8 along with the cesium Freundlich/Langmuir isotherms to simulate the waste decontamination in ion exchange columns, spherical SL644 was found to reduce column cycling by 50% for high-potassium supernates, but sRF performed equally well for the lowest-potassium feeds. Reduced cycling results in reduction of nitric acid (resin elution) and sodium addition (resin regeneration), therefore, significantly reducing life-cycle operational costs. These findings motivate the development of a spherical form of SL644. This work demonstrates the versatility of the ion exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. The value of a resin with increased selectivity for cesium over potassium can be assessed for further development.
Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus
Sarff, J.S.; Almagri, A.F.; Cekic, M.; Den Hartog, D.J.; Fiksel, G.; Hokin, S.A.; Ji, H.; Prager, S.C.; Shen, W.; Stoneking, M.R. (Wisconsin Univ., Madison, WI (United States)); Assadi, S. (Fermi National Accelerator Lab., Batavia, IL (United States)); Sidikman, K.L. (Oak Ridge National Lab., TN (United States))
1992-11-01T23:59:59.000Z
Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 (1991)] using bispectral analysis of edge magnetic fluctuations resolved in k-space. The strength of nonlinear three-wave interactions satisfying the sum rules m[sub 1] + m[sub 2] = m[sub 3] and n[sub 1] + n[sub 2] = n[sub 3] is measured by the bicoherency. In the RFP, m=l, n[approximately]2R/a (6 for MST) internally resonant modes are linearly unstable and grow to large amplitude. Large values of bicoherency occur for two m=l modes coupled to an m=2 mode and the coupling of intermediate toroidal modes, e.g., n=6 and 7 coupled to n=13. These experimental bispectral features agree with predicted bispectral features derived from MHD computation. However, in the experiment, enhanced coupling occurs in the crash'' phase of a sawtooth oscillation concomitant with a broadened mode spectrum suggesting the onset of a nonlinear cascade.
Reversed-field pinch studies in the Madison Symmetric Torus
Hokin, S.; Almagri, A.; Cekic, M.; Chapman, B.; Crocker, N.; Den Hartog, D.J.; Fiksel, G.; Henry, J.; Ji, H.; Prager, S.; Sarff, J.; Scime, E.; Shen, W.; Stoneking, M.; Watts, C.
1993-04-03T23:59:59.000Z
Studies of large-size (R = 1.5 m, a = 0.5 m), moderate current (I < 750 kA) reversed-field pinch (RFP) plasmas are carried out in the Madison Symmetric Torus in order to evaluate and improve RFP confinement, study general toroidal plasma MHD issues, determine the mechanism of the RFP dynamo, and measure fluctuation-induced transport and anomalous ion heating. MST confinement has been improved by reduction of magnetic field errors with correction coils in the primary circuit and reduction of impurities using boronization; high densities have been achieved with hydrogen pellet injection. MHD tearing modes with poloidal mode number m = 1 and toroidal mode numbers n = 5--7 are prevalent and nonlinearly couple to produce sudden relaxations akin to tokamak sawteeth. Edge fluctuation-induced transport has been measured with a variety of insertable probes. Ions exhibit anomalous heating, with increases of ion temperature occuring during strong MHD relaxation. The RFP dynamo has been studied with attention to various possible mechanisms, including motion-EMF drive, the Hall effect, and superthermal electrons. Initial profile control experiments have begun using insertable biased probes and plasma guns. The toroidal field capacity of MST will be upgraded during Summer, 1993 to allow low-current tokamak operation as well as improved RFP operation.
Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus
Sarff, J.S.; Almagri, A.F.; Cekic, M.; Den Hartog, D.J.; Fiksel, G.; Hokin, S.A.; Ji, H.; Prager, S.C.; Shen, W.; Stoneking, M.R. [Wisconsin Univ., Madison, WI (United States); Assadi, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Sidikman, K.L. [Oak Ridge National Lab., TN (United States)
1992-11-01T23:59:59.000Z
Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 (1991)] using bispectral analysis of edge magnetic fluctuations resolved in ``k-space. The strength of nonlinear three-wave interactions satisfying the sum rules m{sub 1} + m{sub 2} = m{sub 3} and n{sub 1} + n{sub 2} = n{sub 3} is measured by the bicoherency. In the RFP, m=l, n{approximately}2R/a (6 for MST) internally resonant modes are linearly unstable and grow to large amplitude. Large values of bicoherency occur for two m=l modes coupled to an m=2 mode and the coupling of intermediate toroidal modes, e.g., n=6 and 7 coupled to n=13. These experimental bispectral features agree with predicted bispectral features derived from MHD computation. However, in the experiment, enhanced coupling occurs in the ``crash`` phase of a sawtooth oscillation concomitant with a broadened mode spectrum suggesting the onset of a nonlinear cascade.
Ideal magnetohydrodynamic equilibrium in a non-symmetric topological torus
Weitzner, Harold [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)] [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)
2014-02-15T23:59:59.000Z
An alternative representation of an ideal magnetohydrodynamic equilibrium is developed. The representation is a variation of one given by A. Salat, Phys. Plasmas 2, 1652 (1995). The system of equations is used to study the possibility of non-symmetric equilibria in a topological torus, here an approximate rectangular parallelopiped, with periodicity in two of the three rectangular coordinates. An expansion is carried out in the deviation of pressure surfaces from planes. Resonances are manifest in the process. Nonetheless, provided the magnetic shear is small, it is shown that it is possible to select the magnetic fields and flux surfaces in such a manner that no singularities appear on resonant surfaces. One boundary surface of the parallelopiped is not arbitrary but is dependent on the equilibrium in question. A comparison of the solution sets of axisymmetric and non-axisymmetric equilibria suggests that the latter have a wider class of possible boundary shapes but more restrictive rotational transform profiles. No proof of convergence of the series is given.
The alternative model of the spherical oscillator
Levon Mardoyan
2007-08-14T23:59:59.000Z
The quasiradial wave functions and energy spectra of the alternative model of spherical oscillator on the $D$-dimensional sphere and two-sheeted hyperboloid are found.
Fourier Modeling of the Radio Torus Surrounding Supernova 1987A
C. -Y. Ng; B. M. Gaensler; L. Staveley-Smith; R. N. Manchester; M. J. Kesteven; L. Ball; A. K. Tzioumis
2008-05-27T23:59:59.000Z
We present detailed Fourier modeling of the radio remnant of Supernova 1987A, using high-resolution 9 GHz and 18 GHz data taken with the Australia Telescope Compact Array over the period 1992 to 2008. We develop a parameterized three-dimensional torus model for the expanding radio shell, in which the emission is confined to an inclined equatorial belt; our model also incorporates both a correction for light travel-time effects and an overall east-west gradient in the radio emissivity. By deriving an analytic expression for the two-dimensional Fourier transform of the projected three-dimensional brightness distribution, we can fit our spatial model directly to the interferometric visibility data. This provides robust estimates to the radio morphology at each epoch. The best-fit results suggest a constant remnant expansion at 4000 +/- 400 km/s over the 16-year period covered by the observations. The model fits also indicate substantial mid-latitude emission, extending to 40 degree on either side of the equatorial plane. This likely corresponds to the extra-planar structure seen in H$\\alpha$ and Ly$\\alpha$ emission from the supernova reverse shock, and broadly supports hydrodynamic models in which the complex circumstellar environment was produced by a progression of interacting winds from the progenitor. Our model quantifies the clear asymmetry seen in the radio images: we find that the eastern half of the radio remnant is consistently ~40 brighter than the western half at all epochs, which may result from an asymmetry in the ejecta distribution between these two hemispheres.
FMEA on the superconducting torus for the Jefferson Lab 12 GeV accelerator upgrade
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ghoshal, Probir K.; Biallas, George H.; Fair, Ruben J.; Rajput-Ghoshal, Renuka; Schneider, William J.; Legg, Robert A.; Kashy, David H.; Hogan, John P.; Wiseman, Mark A.; Luongo, Cesar; et al
2015-01-16T23:59:59.000Z
As part of the Jefferson Lab 12GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes the various failure modes in torus magnet along with the failure modes that could be experienced by the torus and its interaction with the solenoid which is located inmore »close proximity.« less
Gravitational Energy in Spherical Symmetry
Sean A. Hayward
2002-02-17T23:59:59.000Z
Various properties of the Misner-Sharp spherically symmetric gravitational energy E are established or reviewed. In the Newtonian limit of a perfect fluid, E yields the Newtonian mass to leading order and the Newtonian kinetic and potential energy to the next order. For test particles, the corresponding Hajicek energy is conserved and has the behaviour appropriate to energy in the Newtonian and special-relativistic limits. In the small-sphere limit, the leading term in E is the product of volume and the energy density of the matter. In vacuo, E reduces to the Schwarzschild energy. At null and spatial infinity, E reduces to the Bondi-Sachs and Arnowitt-Deser-Misner energies respectively. The conserved Kodama current has charge E. A sphere is trapped if E>r/2, marginal if E=r/2 and untrapped if E0, and temporal and untrapped if Eenergy condition. It follows that E>=0 on an untrapped spatial hypersurface with regular centre, and E>=r_0/2 on an untrapped spatial hypersurface bounded at the inward end by a marginal sphere of radius r_0. All these inequalities extend to the asymptotic energies, recovering the Bondi-Sachs energy loss and the positivity of the asymptotic energies, as well as proving the conjectured Penrose inequality for black or white holes. Implications for the cosmic censorship hypothesis and for general definitions of gravitational energy are discussed.
Osmotic buckling of spherical capsules
Sebastian Knoche; Jan Kierfeld
2014-09-11T23:59:59.000Z
We study the buckling of elastic spherical shells under osmotic pressure with the osmolyte concentration of the exterior solution as control parameter. We compare our results for the bifurcation behavior with results for buckling under mechanical pressure control, that is, with an empty capsule interior. We find striking differences for the buckling states between osmotic and mechanical buckling. Mechanical pressure control always leads to fully collapsed states with opposite sides in contact, whereas uncollapsed states with a single finite dimple are generic for osmotic pressure control. For sufficiently large interior osmolyte concentrations, osmotic pressure control is qualititatively similar to buckling under volume control with the volume prescribed by the osmolyte concentrations inside and outside the shell. We present a quantitative theory which also captures the influence of shell elasticity on the relation between osmotic pressure and volume. These findings are relevant for the control of buckled shapes in applications. We show how the osmolyte concentration can be used to control the volume of buckled shells. An accurate analytic formula is derived for the relation between the osmotic pressure, the elastic moduli and the volume of buckled capsules. This also allows to use elastic capsules as osmotic pressure sensors or to deduce elastic properties and the internal osmolyte concentration from shape changes in response to osmotic pressure changes. We apply our findings to published experimental data on polyelectrolyte capsules.
Bounce-free spherical hydrodynamic implosion
Kagan, Grigory; Tang Xianzhu; Hsu, Scott C.; Awe, Thomas J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2011-12-15T23:59:59.000Z
In a bounce-free spherical hydrodynamic implosion, the post-stagnation hot core plasma does not expand against the imploding flow. Such an implosion scheme has the advantage of improving the dwell time of the burning fuel, resulting in a higher fusion burn-up fraction. The existence of bounce-free spherical implosions is demonstrated by explicitly constructing a family of self-similar solutions to the spherically symmetric ideal hydrodynamic equations. When applied to a specific example of plasma liner driven magneto-inertial fusion, the bounce-free solution is found to produce at least a factor of four improvement in dwell time and fusion energy gain.
Preliminary Physics Motivation and Engineering Design Assessment of the National High Power Torus
Robert D. Woolley
2009-06-11T23:59:59.000Z
In April 2006, Dr. Ray Orbach, Director of the DOE Office of Science, challenged the fusion community to "propose a new facility... which will put the U.S. at the lead in world fusion science." Analysis of the gaps between expected ITER performance and the requirements of a demonstration power plant (Demo) pointed to the critical and urgent need to develop fusion-relvant plasma-material interface (PMI) solutions consistent with sustained high plasma performance. A survey of world fusion program indicated that present and planned experimental devices do not advance the PMI issue beyond ITER, and a major dedicated experimental facility is warranted. Such a facility should provide the flexibility and access needed to solve plasma boundary challenges related to divertor heat flux and particle exhaust while also developing methods to minimize hydrogenic isotope retention and remaining compatible with high plasma performance.
FY 2008 Miniature Spherical Retroreflectors – Final Report
Anheier, Norman C.; Bernacki, Bruce E.; Klymyshyn, Nicholas A.; Krishnaswami, Kannan; Rodriguez, Carmen P.
2009-02-01T23:59:59.000Z
Through the duration of the NNSA Office of Nuclear Nonproliferation Research and Development (NA-22) Miniature Spherical Retroreflectors lifecycle project, our research team focused on developing solutions to the fabrication bottleneck that has inhibited development and deployment of wide-angle optically interrogated chemical and radiological remote sensing technology. Our team advanced the concept of step-index clad retroreflectors to approximate an optimized, but yet unrealized spherical gradient index design. An intensive numerical simulation effort was undertaken that resulted in optimized step-index optical designs for mid-infrared applications. Geometric optics ray trace modeling was performed to better understand the geometrical dependencies of the miniature spherical retroreflector application. We adopted and advanced the concept of optical cross section, a metric that provides relative performance comparisons between different retroreflector designs and our cross-section analysis demonstrated that our step-index design provided 90% of the range capacity of the ideal spherical index design.
Method for making spherical binderless pellets
Grubbs, Donald K. (Rector, PA); Kochanowski, Andrew T. (Spring Church, PA)
1983-01-01T23:59:59.000Z
A method for making spherical binderless pellets using a rotating drum mixer whereby at least a portion of the particles comprising the pellets is comprised of coking coal particles.
Thermoelectric Rotating Torus for Fusion A. B. Hassam and Yi-Min Huang
Hassam, Adil
for thermonuclear fusion that, if realizable, would offer some novel advan- tages over conventional fusionThermoelectric Rotating Torus for Fusion A. B. Hassam and Yi-Min Huang Institute for Plasma. Such a system has two novel advantages as a fusion device: there are no strong electro- magnets needed to create
DEPLETED MAGNETIC FLUX TUBES AS PROBES OF THE IO TORUS PLASMA
Russell, Christopher T.
that they were depleted in their energy content. These tubes have not been seen on every return to the Io torus to that of corotation. A plausible source for these empty flux tubes is reconnection in the post midnight sector tubes has recently been published [Russell et al., 2000b]. In this update we examine the statistics
45Fuel Level in a Spherical Tank Spherical tanks are found in many
45Fuel Level in a Spherical Tank Spherical tanks are found in many different situations, from the storage of cryogenic liquids, to fuel tanks. Under the influence of gravity, or acceleration, the liquid then be designed to measure where the surface of the liquid is, and from this derive h. Problem 1 - Slice the fluid
Direct-illumination spherical-target experiments
Johnson, R.R.
1982-01-01T23:59:59.000Z
A set of spherical target experiments was designed to evaluate the effectiveness of three techniques for achieving higher convergence implosions. They are (1) cryogenically frozen fuel layers, (2) submicron wavelength laser light, and (3) temporally tailored pulse shapes. A second set of experiments provides information about energy transport by thermal and suprathermal electrons and uses multilayered targets as an integral component of the diagnostics. These results, in conjunction with existing laser-target coupling data, provide a more comprehensive test of our understanding of laser plasma interaction, energy transport, and hydrodynamic response of small scale spherical laser fusion experiments.
Simple flexible polymers in a spherical cage
M. Marenz; J. Zierenberg; H. Arkin; W. Janke
2012-12-26T23:59:59.000Z
We report the results of Monte Carlo simulations investigating the effect of a spherical confinement within a simple model for a flexible homopolymer. We use the parallel tempering method combined with multi-histogram reweighting analysis and multicanonical simulations to investigate thermodynamical observables over a broad range of temperatures, which enables us to describe the behavior of the polymer and to locate the freezing and collapse transitions. We find a strong effect of the spherical confinement on the location of the collapse transition, whereas the freezing transition is hardly effected.
Lagrange multiplier and Wess-Zumino variable as large extra dimensions in the torus universe
Nejad, Salman Abarghouei; Monemzadeh, Majid
2015-01-01T23:59:59.000Z
We study the effect of the topology of universe by gauging the non-relativistic particle model on the torus and 3-torus, using the symplectic formalism of constrained systems and embedding those models on extended phase-spaces. Also, we obtain the generators of the gauge transformations for gauged models. Extracting the corresponding Poisson structure of the existed constraints, we show the effect of the topology on the canonical structure of the phase-spaces of those models and suggest some phenomenology to prove the topology of the universe and probable non-commutative structure of the space. In addition, we show that the number of large extra dimensions in the Phase-spaces of the gauged embeded models are exactly two. Moreover, in the classical form, we talk over MOND theory in order to study the origin of the terms appeared in the gauged theory, which modify the Newton's second law.
Line-tension effects on heterogeneous nucleation on a spherical substrate and in a spherical cavity
Masao Iwamatsu
2015-03-17T23:59:59.000Z
The line-tension effects on heterogeneous nucleation are considered when a spherical lens-shaped nucleus is nucleated on top of a spherical substrate and on the bottom of the wall of a spherical cavity. The effect of line tension on the nucleation barrier can be separated from the usual volume term. As the radius of the substrate increases, the nucleation barrier decreases and approaches that of a flat substrate. However, as the radius of the cavity increases, the nucleation barrier increases and approaches that of a flat substrate. A small spherical substrate is a less active nucleation site than a flat substrate, and a small spherical cavity is a more active nucleation site than a flat substrate. In contrast, the line-tension effect on the nucleation barrier is maximum when the radii of the nucleus and the substrate or cavity become comparable. Therefore, by tuning the size of the spherical substrate or spherical cavity, the effect of the line tension can be optimized. These results will be useful in broad range of applications from material processing to understanding of global climate, where the heterogeneous nucleation plays a vital role.
Condensates and instanton - torus knot duality. Hidden Physics at UV scale
A. Gorsky; A. Milekhin
2014-12-29T23:59:59.000Z
We establish the duality between the torus knot superpolynomials or the Poincare polynomials of the Khovanov homology and particular condensates in Omega-deformed 5D supersymmetric QED compactified on a circle with 5d Chern-Simons(CS) term. This is the generalization of the Witten's recipe of the evaluation of the knot polynomials via Wilson loops in 3d CS theory for case of the torus knots. It is explicitly shown that $n$-instanton contribution to the condensate of the massless flavor in the background of four-observable, which can be associated with some composite defect, exactly coincides with the superpolynomial of the T(n,nk+1) torus knot where k - is the level of CS term. In contrast to the previously known results, the particular torus knot corresponds not to the partition function of the gauge theory but to the particular instanton contribution and summation over the knots has to be performed in order to obtain the complete answer. The instantons are sitting almost at the top of each other and the physics of the "fat point" where the UV degrees of freedom are slaved with point-like instantons turns out to be quite rich. Also also see knot polynomials in the quantum mechanics on the instanton moduli space. We consider the different limits of this correspondence focusing at their physical interpretation and compare the algebraic structures at the both sides of the correspondence. Using the AGT correspondence, we establish a connection between superpolynomials for unknots and q-deformed DOZZ factors which suggests the interpretation of the composite defect.
High-speed three-wave polarimeter-interferometer diagnostic for Madison symmetric torus
Deng, B. H.; Brower, D. L.; Ding, W. X.; Wyman, M. D.; Chapman, B. E.; Sarff, J. S. [Electrical Engineering Department, University of California, Los Angeles, California 90095 (United States); Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)
2006-10-15T23:59:59.000Z
A high-speed three-wave polarimeter-interferometer diagnostic has been developed on the Madison symmetric torus reversed field pinch to provide simultaneous measurement of electron density and poloidal magnetic field profile evolution. With increased digitizer bandwidth, polarimetry noise due to aliasing and cross-talk is minimized, and time response improved. System performance is demonstrated by measurements of equilibrium profile evolution during fast events such as the sawtooth crash and pellet injection.
Two intervals R\\'enyi entanglement entropy of compact free boson on torus
Liu, Feihu
2015-01-01T23:59:59.000Z
We compute the $N=2$ R\\'enyi entanglement entropy of two intervals at equal time in a circle, for the theory of a 2d compact complex free scalar at finite temperature. This is carried out by performing functional integral on a genus 3 ramified cover of the torus, wherein the quantum part of the integral is captured by the four point function of twist fields on the worldsheet torus, and the classical piece is given by summing over winding modes of the genus 3 surface onto the target space torus. The final result is given in terms of a product of theta function and certain multi-dimensional theta function. We demonstrate the T-duality invariance of the result. We also study its low temperature limit. In the case in which the size of the intervals and of their separation are much smaller than the whole system, our result is in exact agreement with the known result for two intervals on an infinite system at zero temperature \\cite{eeoftwo}. In the case in which the separation between the two intervals is much smal...
ATM SPHERIC SCIENCES THE DEPARTMENT OF
-time faculty and 143 undergraduates (Fall 2006), students in the Department of Atmospher- ic Sciences enjoyATM SPHERIC SCIENCES THE DEPARTMENT OF Department of Atmospheric Sciences Texas A&M University Atmospheric science, the study of the physics and chemistry of the atmosphere, includes meteorology
Spherically symmetric monopoles in noncommutative space
Moreno, E.F. [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata (Argentina) and Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)
2005-08-15T23:59:59.000Z
We construct a spherically symmetric noncommutative space in three dimensions by foliating the space with concentric fuzzy spheres. We show how to construct a gauge theory in this space, and, in particular, we derive the noncommutative version of a Yang-Mills-Higgs theory. We find numerical monopole solutions of the equations of motion.
Brachistochrone of a Spherical Uniform Mass Distribution
David R. Mitchell
2008-08-23T23:59:59.000Z
We solve the brachistochrone problem for a particle travelling through a spherical mass distribution of uniform density. We examine the connection between this problem and the popular "gravity elevator" result. The solution is compared to the well known brachistochrone problem of a particle in a uniform gravitational field.
Fast Ion Stabilization of the Ion Temperature Gradient Driven Modes in the Joint European Torus Hybrid-Scenario Plasmas: A Trigger Mechanism for Internal Transport Barrier Formation
A New Sawtooth Control Mechanism Relying on Toroidally Propagating Ion Cyclotron Resonance Frequency Waves: Theory and Joint European Torus Tokamak Experimental Evidence
Dynamic Spherical Volumetric Simplex Splines with Applications in Biomedical Simulation
Hua, Jing
Dynamic Spherical Volumetric Simplex Splines with Applications in Biomedical Simulation Yunhao Tan computational framework based on dy- namic spherical volumetric simplex splines for simulation of genus- zero to reconstruct the high-fidelity digi- tal model of a real-world object with spherical volumetric simplex splines
Imaging with Spherically Bent Crystals or Reflectors
Bitter, M; Hill, K W; Scott, S; Ince-Cushman, A; Reinke, M; Podpaly, Y; Rice, J E; Beiersdorfer, P
2010-06-01T23:59:59.000Z
This paper consists of two parts: Part I describes the working principle of a recently developed x-ray imaging crystal spectrometer, where the astigmatism of spherically bent crystals is being used with advantage to record spatially resolved spectra of highly charged ions for Doppler measurements of the ion-temperature and toroidal plasmarotation- velocity profiles in tokamak plasmas. This type of spectrometer was thoroughly tested on NSTX and Alcator C-Mod, and its concept was recently adopted for the design of the ITER crystal spectrometers. Part II describes imaging schemes, where the astigmatism has been eliminated by the use of matched pairs of spherically bent crystals or reflectors. These imaging schemes are applicable over a wide range of the electromagnetic radiation, which includes microwaves, visible light, EUV radiation, and x-rays. Potential applications with EUV radiation and x-rays are the diagnosis of laserproduced plasmas, imaging of biological samples with synchrotron radiation, and lithography.
Multipole polarizability of a graded spherical particle
L. Dong; J. P. Huang; K. W. Yu; G. Q. Gu
2005-12-01T23:59:59.000Z
We have studied the multipole polarizability of a graded spherical particle in a nonuniform electric field, in which the conductivity can vary radially inside the particle. The main objective of this work is to access the effects of multipole interactions at small interparticle separations, which can be important in non-dilute suspensions of functionally graded materials. The nonuniform electric field arises either from that applied on the particle or from the local field of all other particles. We developed a differential effective multipole moment approximation (DEMMA) to compute the multipole moment of a graded spherical particle in a nonuniform external field. Moreover, we compare the DEMMA results with the exact results of the power-law graded profile and the agreement is excellent. The extension to anisotropic DEMMA will be studied in an Appendix.
Structure of the Spherical Black Hole Interior
A. Bonanno; S. Droz; W. Israel; S. M. Morsink
1994-11-18T23:59:59.000Z
The internal structure of a charged spherical black hole is still a topic of debate. In a nonrotating but aspherical gravitational collapse to form a spherical charged black hole, the backscattered gravitational wave tails enter the black hole and are blueshifted at the Cauchy horizon. This has a catastrophic effect if combined with an outflux crossing the Cauchy horizon: a singularity develops at the Cauchy horizon and the effective mass inflates. Recently a numerical study of a massless scalar field in the \\RN background suggested that a spacelike singularity may form before the Cauchy horizon forms. We will show that there exists an approximate analytic solution of the scalar field equations which allows the mass inflation singularity at the Cauchy horizon to exist. In particular, we see no evidence that the Cauchy horizon is preceded by a spacelike singularity.
Simulation of spherically expanding turbulent premixed flames
Ahmed, I.; Swaminathan, N.
2013-09-16T23:59:59.000Z
canonically im- portant configuration and its investigation is helpful to understand combustion in prac- tical devices such as the spark ignited internal combustion engine, modern stratified charge engines and accidental explosions of fuel vapour cloud... Simulation of spherically expanding turbulent premixed flames I. Ahmed, N. Swaminathan? Department of Engineering, Cambridge University, Cambridge, CB2 1PZ, UK. ?Corresponding author: Department of Engineering, Cambridge University, Trumpington...
Monumental effort: How a dedicated team completed a massive beam...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Spherical Torus Experiment-Upgrade (NSTX-U) and double the experiment's heating power. Oh, and while you're at it, hoist the two-story tall box over a 22-foot wall....
Tomuro, H.; Asai, T.; Iguchi, K.; Takahashi, Ts.; Hirano, Y. [Department of Physics, College of Science and Technology, Nihon University, Tokyo 101-8308 (Japan)
2010-10-15T23:59:59.000Z
A compact tomography camera system consisting of a photomultiplier tube, a multislit optical system, and a band-pass interference filter has been developed. The viewing area and spatial resolution can be configured by the arrangement of the slit system. The camera system has been specially designed for self-organized compact torus experiments having strong magnetohydrodynamics events with a submicrosecond time-scale. The developed system has been tested on a field-reversed configuration formed by the field-reversed theta-pinch. Performance evaluation of the system has been performed by comparison to the former optical system.
Karney, Charles
VOLUME54, NUMBER9 PHYSICAL REVIEW LETTERS 4 MARCH1985 Conversion of Wave Energy to Magnetic Field on the Princeton Large Torus (PLT)' have converted wave energy to poloidal field energy with the remarkable Energy in a Plasma Torus N. J. Fisch and C. F. F. Karney Plasma Physics Laboratory, Princeton University
Conformal perturbation theory and higher spin entanglement entropy on the torus
Shouvik Datta; Justin R. David; S. Prem Kumar
2015-04-10T23:59:59.000Z
We study the free fermion theory in 1+1 dimensions deformed by chemical potentials for holomorphic, conserved currents at finite temperature and on a spatial circle. For a spin-three chemical potential \\mu, the deformation is related at high temperatures to a higher spin black hole in hs[0] theory on AdS_3 spacetime. We calculate the order \\mu^2 corrections to the single interval Renyi and entanglement entropies on the torus using the bosonized formulation. A consistent result, satisfying all checks, emerges upon carefully accounting for both perturbative and winding mode contributions in the bosonized language. The order \\mu^2 corrections involve integrals that are finite but potentially sensitive to contact term singularities. We propose and apply a prescription for defining such integrals which matches the Hamiltonian picture and passes several non-trivial checks for both thermal corrections and the Renyi entropies at this order. The thermal corrections are given by a weight six quasi-modular form, whilst the Renyi entropies are controlled by quasi-elliptic functions of the interval length with modular weight six. We also point out the well known connection between the perturbative expansion of the partition function in powers of the spin-three chemical potential and the Gross-Taylor genus expansion of large-N Yang-Mills theory on the torus. We note the absence of winding mode contributions in this connection, which suggests qualitatively different entanglement entropies for the two systems.
TORUS: Theory of Reactions for Unstable iSotopes - Year 1 Continuation and Progress Report
Arbanas, G; Elster, C; Escher, J; Mukhamedzhanov, A; Nunes, F; Thompson, I J
2011-02-24T23:59:59.000Z
The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding started on June 1, 2010, it will have been running for nine months by the date of submission of this Annual Continuation and Progress Report on March 1, 2011. The extent of funding was reduced from the original application, and now supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.
Spherically Symmetric Gravitational Collapse of Perfect Fluids
P. D. Lasky; A. W. C. Lun
2006-10-31T23:59:59.000Z
Formulating a perfect fluid filled spherically symmetric metric utilizing the 3+1 formalism for general relativity, we show that the metric coefficients are completely determined by the mass-energy distribution, and its time rate of change on an initial spacelike hypersurface. Rather than specifying Schwarzschild coordinates for the exterior of the collapsing region, we let the interior dictate the form of the solution in the exterior, and thus both regions are found to be written in one coordinate patch. This not only alleviates the need for complicated matching schemes at the interface, but also finds a new coordinate system for the Schwarzschild spacetime expressed in generalized Painleve-Gullstrand coordinates.
Quasi-spherical direct drive fusion.
VanDevender, J. Pace; Abbott, Lucas M.; Langston, William L.; McDaniel, Dillon Heirman; Nash, Thomas J.; Roderick, Norman Frederick; Silva, M.
2007-01-01T23:59:59.000Z
The authors present designs of quasi-spherical direction drive z-pinch loads for machines such as ZR at 28 MA load current with a 150 ns implosion time (QSDDI). A double shell system for ZR has produced a 2D simulated yield of 12 MJ, but the drive for this system on ZR has essentially no margin. A double shell system for a 56 MA driver at 150 ns implosion has produced a simulated yield of 130 MJ with considerable margin in attaining the necessary temperature and density-radius product for ignition. They also represent designs for a magnetically insulated current amplifier, (MICA), that modify the attainable ZR load current to 36 MA with a 28 ns rise time. The faster pulse provided by a MICA makes it possible to drive quasi-spherical single shell implosions (QSDD2). They present results from 1D LASNEX and 2D MACH2 simulations of promising low-adiabat cryogenic QSDD2 capsules and 1D LASNEX results of high-adiabat cryogenic QSDD2 capsules.
Spherically symmetric conformal gravity and "gravitational bubbles"
V. A. Berezin; V. I. Dokuchaev; Yu. N. Eroshenko
2014-12-09T23:59:59.000Z
The general structure of the spherically symmetric solutions in the Weyl conformal gravity is described. The corresponding Bach equation are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions is found. It consists of two classes. The first one contains the solutions with constant two-dimensional curvature scalar of our specific metrics, and the representatives are the famous Robertson-Walker metrics. One of them we called the "gravitational bubbles", which is compact and with zero Weyl tensor. The second class is more general, with varying curvature scalar. We found its representative as the one-parameter family. It appears that it can be conformally covered by the thee-parameter Mannheim-Kazanas solution. We also investigated the general structure of the energy-momentum tensor in the spherical conformal gravity and constructed the vectorial equation that reveals clearly the same features of non-vacuum solutions. One of them, the metrics a la Vaidya, is explicitly written.
Major Milestone: PPPL completes first quadrant of the heart of the National
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville PowerTariff Pages default Sign InCenter3.82 4.23 1967-20103,Magnetic2-000MaintainingSpherical Torus
Neutrino oscillations in the general spherically symmetric gravitational field
Godunov, S. I., E-mail: sgodunov@itep.ru; Pastukhov, G. S., E-mail: grigoriypas@gmail.com [Institute for Theoretical and Experimental Physics (Russian Federation)
2012-09-15T23:59:59.000Z
The results for neutrino oscillations in the gravitational field described by the Schwarzschild metric are generalized to the general spherically symmetric gravitational field.
Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization for the periodic orbits in a strongly coupled multidimen- sional Hamiltonian system, namely the hydrogen atom.15.Gy, 05.45.-a, 45.20.Jj I. INTRODUCTION The hydrogen atom in crossed electric and magnetic fields
Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies
Koshida, Shintaro [Center of Astro Engineering and Department of Electrical Engineering, Pontificia Univercsidad Catolica de Chile, Av. Vicuna Mackenna 4868 (Chile); Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota [Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Kobayashi, Yukiyasu; Suganuma, Masahiro [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Enya, Keigo [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Tomita, Hiroyuki; Aoki, Tsutomu [Kiso Observatory, Institute of Astronomy, School of Science, University of Tokyo, 10762-30 Mitake, Kiso, Nagano 397-0101 (Japan); Peterson, Bruce A., E-mail: skoshida@ing.puc.cl, E-mail: minezaki@ioa.s.u-tokyo.ac.jp [Mount Stromlo Observatory, Research School of Astronomy and Astrophysics, Australian National University, Weston Creek P.O., ACT 2611 (Australia)
2014-06-20T23:59:59.000Z
We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log ?t (days) = –2.11 – 0.2 M{sub V} assuming ?t?L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified scheme of the Seyfert type of active galactic nuclei (AGNs). Moreover, we examined the radius-luminosity correlations for the hard X-ray (14-195 keV) and the [O IV] ?25.89 ?m emission-line luminosities, which would be applicable for obscured AGNs.
Dynamical friction force exerted on spherical bodies
O. Esquivel; B. Fuchs
2007-04-30T23:59:59.000Z
We present a rigorous calculation of the dynamical friction force exerted on a spherical massive perturber moving through an infinite homogenous system of field stars. By calculating the shape and mass of the polarization cloud induced by the perturber in the background system, which decelerates the motion of the perturber, we recover Chandrasekhar's drag force law with a modified Coulomb logarithm. As concrete examples we calculate the drag force exerted on a Plummer sphere or a sphere with the density distribution of a Hernquist profile. It is shown that the shape of the perturber affects only the exact form of the Coulomb logarithm. The latter converges on small scales, because encounters of the test and field stars with impact parameters less than the size of the massive perturber become inefficient. We confirm this way earlier results based on the impulse approximation of small angle scatterings.
Dynamical friction force exerted on spherical bodies
Esquivel, O
2007-01-01T23:59:59.000Z
We present a rigorous calculation of the dynamical friction force exerted on a spherical massive perturber moving through an infinite homogenous system of field stars. By calculating the shape and mass of the polarization cloud induced by the perturber in the background system, which decelerates the motion of the perturber, we recover Chandrasekhar's drag force law with a modified Coulomb logarithm. As concrete examples we calculate the drag force exerted on a Plummer sphere or a sphere with the density distribution of a Hernquist profile. It is shown that the shape of the perturber affects only the exact form of the Coulomb logarithm. The latter converges on small scales, because encounters of the test and field stars with impact parameters less than the size of the massive perturber become inefficient. We confirm this way earlier results based on the impulse approximation of small angle scatterings.
Polymer ejection from strong spherical confinement
J. Piili; R. P. Linna
2015-05-27T23:59:59.000Z
We examine the ejection of an initially strongly confined flexible polymer from a spherical capsid through a nanoscale pore. We use molecular dynamics for unprecedentedly high initial monomer densities. We show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers. By measurements of the force at the pore we show this dependence to be a consequence of the excess free energy of the polymer due to confinement growing exponentially with the number of monomers initially inside the capsid. We show that the pressure inside the capsid driving the ejection dominates the process that is characterized by the ejection time growing linearly with the lengths of different polymers. We show that the superlinear dependence obtained for polymers amenable to computer simulations results from a finite-size effect due to the final retraction of polymers' tails from capsids.
Thermodynamic motivations of spherically symmetric static metrics
H. Moradpour; S. Nasirimoghadam
2015-06-14T23:59:59.000Z
Bearing the thermodynamic arguments together with the two definitions of mass in mind, we try to find metrics with spherical symmetry. We consider the adiabatic condition along with the Gong-Wang mass, and evaluate the $g_{rr}$ element which points to a null hypersurface. In addition, we generalize the thermodynamics laws to this hypersurface to find its temperature and thus the corresponding surface gravity which enables us to get a relation for the $g_{tt}$ element. Finally, we investigate the mathematical and physical properties of the discovered metric in the Einstein relativity framework which shows that the primary mentioned null hypersurface is an event horizon. We also show that if one considers the Misner-Sharp mass in the calculations, the Schwarzschild metric will be got. The relationship between the two mass definitions in each metric is studied. The results of considering the geometrical surface gravity are also addressed.
Thermodynamic motivations of spherically symmetric static metrics
Moradpour, H
2015-01-01T23:59:59.000Z
Bearing the thermodynamic arguments together with the two definitions of mass in mind, we try to find metrics with spherical symmetry. We consider the adiabatic condition along with the Gong-Wang mass, and evaluate the $g_{rr}$ element which points to a null hypersurface. In addition, we generalize the thermodynamics laws to this hypersurface to find its temperature and thus the corresponding surface gravity which enables us to get a relation for the $g_{tt}$ element. Finally, we investigate the mathematical and physical properties of the discovered metric in the Einstein relativity framework which shows that the primary mentioned null hypersurface is an event horizon. We also show that if one considers the Misner-Sharp mass in the calculations, the Schwarzschild metric will be got. The relationship between the two mass definitions in each metric is studied. The results of considering the geometrical surface gravity are also addressed.
Spectral asymmetry of the massless Dirac operator on a 3-torus
Downes, Robert J., E-mail: R.Downes@ucl.ac.uk; Vassiliev, Dmitri, E-mail: D.Vassiliev@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London WC1E 6BT (United Kingdom)] [Department of Mathematics, University College London, Gower Street, London WC1E 6BT (United Kingdom); Levitin, Michael, E-mail: M.Levitin@reading.ac.uk [Department of Mathematics and Statistics, University of Reading, Whiteknights, PO Box 220, Reading RG6 6AX (United Kingdom)] [Department of Mathematics and Statistics, University of Reading, Whiteknights, PO Box 220, Reading RG6 6AX (United Kingdom)
2013-11-15T23:59:59.000Z
Consider the massless Dirac operator on a 3-torus equipped with Euclidean metric and standard spin structure. It is known that the eigenvalues can be calculated explicitly: the spectrum is symmetric about zero and zero itself is a double eigenvalue. The aim of the paper is to develop a perturbation theory for the eigenvalue with smallest modulus with respect to perturbations of the metric. Here the application of perturbation techniques is hindered by the fact that eigenvalues of the massless Dirac operator have even multiplicity, which is a consequence of this operator commuting with the antilinear operator of charge conjugation (a peculiar feature of dimension 3). We derive an asymptotic formula for the eigenvalue with smallest modulus for arbitrary perturbations of the metric and present two particular families of Riemannian metrics for which the eigenvalue with smallest modulus can be evaluated explicitly. We also establish a relation between our asymptotic formula and the eta invariant.
First Studies of Pure Electron Plasmas in the Columbia Non-neutral Torus
Berkery, J. W.; Pedersen, T. S.; Kremer, J. P.; Lefrancois, R. G.; Marksteiner, Q. R.; Boozer, A. H. [Dept. of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027 (United States); Mynick, H. E.; Pomphrey, N.; Reiersen, W.; Dahlgreen, F. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Himura, H. [Kyoto Institute of Technology, Kyoto (Japan); Sarasola, X. [CIEMAT, Madrid (Spain)
2006-10-18T23:59:59.000Z
The first studies of pure electron plasmas confined on magnetic surfaces in the Columbia Non-neutral Torus are overviewed. The electron plasma is created by a thermionic emitter filament and similar filaments mounted on ceramic rods are used as Langmuir and emissive probes. The equilibrium density, temperature and potential profiles are experimentally measured. Numerical calculations of the equilibrium agree well with measurements and also predict a toroidal density variation of a factor of four. The confinement time is found to decrease with increased neutral pressure and emitter bias voltage, and it is presently limited to 20 ms by the insulated emitter and probe rods. A retractable electron emitter and external diagnostics will be used to determine the confinement time in the absence of rods. Ion driven instabilities are observed at high neutral pressure and low magnetic field strength. Further research of these instabilities will be carried out.
Cartolano, M. S.; Craig, D., E-mail: darren.craig@wheaton.edu [Wheaton College, Wheaton, Illinois 60187 (United States); Den Hartog, D. J.; Kumar, S. T. A.; Nornberg, M. D. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States) [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, Madison, Wisconsin 53706 (United States)
2014-01-15T23:59:59.000Z
The connection between impurity ion heating and other physical processes in the plasma is evaluated by studying variations in the amount of ion heating at reconnection events in the Madison Symmetric Torus (MST). Correlation of the change in ion temperature with individual tearing mode amplitudes indicates that the edge-resonant modes are better predictors for the amount of global ion heating than the core-resonant modes. There is also a strong correlation between ion heating and current profile relaxation. Simultaneous measurements of the ion temperature at different toroidal locations reveal, for the first time, a toroidal asymmetry to the ion heating in MST. These results present challenges for existing heating theories and suggest a stronger connection between edge-resonant tearing modes, current profile relaxation, and ion heating than has been previously thought.
Compact Torus Accelerator Driven Inertial Confinement Fusion Power Plant HYLIFE-CT
Logan, B G; Moir, R W; Tabak, M; Bieri, R L; Hammer, J H; Hartman, C W; Hoffman, M A; Leber, R L; Petzoldt, R W; Tobin, M T
2005-03-30T23:59:59.000Z
A Compact Torus Accelerator (CTA) is used to accelerate a Compact Torus (CT) to 35 MJ kinetic energy which is focused to a 20 mm diameter where its kinetic energy is converted to a shaped x-ray pulse of 30 MJ. The capsule yield with a prescribed radiation profile is calculated to be (gain 60 times 30 MJ) 1.8 GJ. Schemes for achieving this profile are described. The CT is accelerated in a length of 30 m within an annulus of 150 mm ID and 300 mm OD where the maximum magnetic field is 28 T. A 2.5 m conical taper reduces the mean diameter of the CT from 225 mm to 20 mm. The conical section is made out of solid Li{sub 2}BeF{sub 4}. The target with its frozen conical guide section is accurately placed at the end of the accelerator about once per second. The reactor called HYLIFE uses liquid jets to attenuate blast effects including shrapnel from the shattered conical guide section and radiation so that the vessel is expected to last 30 years. The calculated cost of electricity is estimated (in constant 1988 dollars) to be about 4.8 cents/kW {center_dot} h compared to the future cost of nuclear and coal of 4.3 to 5.8 cents/kW {center_dot} h. The CT driver contributes 17% to the cost of electricity. Present CT's make 2 x 10{sup 8} W/cm{sup 2}; the goal of experiments in progress is 10{sup 11} W/cm{sup 2} with further modifications to allow 10{sup 12}W/cm{sup 2}, whereas the reactor requires 10{sup 15} W/cm{sup 2} in a shaped pulse.
Orthogonal fast spherical Bessel transform on uniform grid
Serov, Vladislav V
2015-01-01T23:59:59.000Z
We propose an algorithm for the orthogonal fast discrete spherical Bessel transform on an uniform grid. Our approach is based upon the spherical Bessel transform factorization into the two subsequent orthogonal transforms, namely the fast Fourier transform and the orthogonal transform founded on the derivatives of the discrete Legendre orthogonal polynomials.
Photonic crystals Fabrication of Tunable Spherical Colloidal Crystals
Photonic crystals Fabrication of Tunable Spherical Colloidal Crystals Immobilized in Soft Hydrogels** Toshimitsu Kanai, Daeyeon Lee, Ho Cheung Shum, and David A. Weitz* Spherical colloidal crystals are three as photonic crystals in the optical regime.[2] In contrast to conventional film-type colloidal crystals where
Osmotic buckling of spherical capsules Sebastian Knoche and Jan Kierfeld*
Kierfeld, Jan
Osmotic buckling of spherical capsules Sebastian Knoche and Jan Kierfeld* We study the buckling of elastic spherical shells under osmotic pressure with the osmolyte concentration of the exterior solution for the buckling states between osmotic and mechanical buckling. Mechanical pressure control always leads to fully
Some improvements to the spherical collapse model
Antonino Del Popolo
2008-01-07T23:59:59.000Z
I study the joint effect of dynamical friction, tidal torques and cosmological constant on clusters of galaxies formation I show that within high-density environments, such as rich clusters of galaxies, both dynamical friction and tidal torques slows down the collapse of low-? peaks producing an observable variation in the time of collapse of the perturbation and, as a consequence, a reduction in the mass bound to the collapsed perturbation Moreover, the delay of the collapse produces a tendency for less dense regions to accrete less mass, with respect to a classical spherical model, inducing a biasing of over-dense regions toward higher mass I show how the threshold of collapse is modified if dynamical friction, tidal torques and a non-zero cosmological constant are taken into account and I use the Extended Press Schecter (EPS) approach to calculate the effects on the mass function Then, I compare the numerical mass function given in Reed et al (2003) with the theoretical mass function obtained in the present paper I show that the barrier obtained in the present paper gives rise to a better description of the mass function evolution with respect to other previous models (Sheth & Tormen 1999, MNRAS, 308, 119 (hereafter ST); Sheth & Tormen 2002, MNRAS, 329, 61 (hereafter ST1))
BROOKHAVEN NATIONAL LABORATORY'S HIGH FLUX BEAM REACTOR
Ohta, Shigemi
1 BROOKHAVEN NATIONAL LABORATORY'S HIGH FLUX BEAM REACTOR Compiled by S. M. Shapiro I. PICTORIAL with fiberglass insulation and a protective aluminum skin. The reactor vessel is shaped somewhat like a very large at the spherical end. It is located at the center of the reactor building and is surrounded by a lead and steel
Marc Briant
2015-07-11T23:59:59.000Z
We investigate the Boltzmann equation, depending on the Knudsen number, in the Navier-Stokes perturbative setting on the torus. Using hypocoercivity, we derive a new proof of existence and exponential decay for solutions close to a global equilibrium, with explicit regularity bounds and rates of convergence. These results are uniform in the Knudsen number and thus allow us to obtain a strong derivation of the incompressible Navier-Stokes equations as the Knudsen number tends to $0$. Moreover, our method is also used to deal with other kinetic models. Finally, we show that the study of the hydrodynamical limit is rather different on the torus than the one already proved in the whole space as it requires averaging in time, unless the initial layer conditions are satisfied.
Stephan Gekle; Jörg Main; Thomas Bartsch; T. Uzer
2006-10-02T23:59:59.000Z
A hierarchical ordering is demonstrated for the periodic orbits in a strongly coupled multidimensional Hamiltonian system, namely the hydrogen atom in crossed electric and magnetic fields. It mirrors the hierarchy of broken resonant tori and thereby allows one to characterize the periodic orbits by a set of winding numbers. With this knowledge, we construct the action variables as functions of the frequency ratios and carry out a semiclassical torus quantization. The semiclassical energy levels thus obtained agree well with exact quantum calculations.
An axisymmetric hydrodynamical model for the torus wind in AGN. II: X-ray excited funnel flow
A. Dorodnitsyn; T. Kallman; D. Proga
2008-06-23T23:59:59.000Z
We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating a strong biconical outflow is observed in our simulations. We calculate 3-dimensional hydrodynamical models, assuming axial symmetry, and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes and temperature, as functions of the torus properties and X-ray flux. Synthetic warm absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds which are comparable to those which have been inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorption line spectra.
An axisymmetric hydrodynamical model for the torus wind in AGN. II: X-ray excited funnel flow
Dorodnitsyn, A; Proga, D
2008-01-01T23:59:59.000Z
We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating a strong biconical outflow is observed in our simulations. We calculate 3-dimensional hydrodynamical models, assuming axial symmetry, and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes and temperature, as functions of the torus properties and X-ray flux. Synthetic warm absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds which are comparable to those which have been inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorp...
Janiuk, Agnieszka; Mioduszewski, Patryk [Center for Theoretical Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Moscibrodzka, Monika, E-mail: agnes@cft.edu.pl [Department of Physics, University of Nevada Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV 89154 (United States)
2013-10-20T23:59:59.000Z
We calculate the structure and short-term evolution of a gamma-ray burst (GRB) central engine in the form of a turbulent torus accreting onto a stellar mass black hole. Our models apply to the short GRB events, in which a remnant torus forms after the neutron star-black hole or a double neutron star merger and is subsequently accreted. We study the two-dimensional, relativistic models and concentrate on the effects of the black hole and flow parameters as well as the neutrino cooling. We compare the resulting structure and neutrino emission to the results of our previous one-dimensional simulations. We find that the neutrino cooled torus launches a powerful mass outflow, which contributes to the total neutrino luminosity and mass loss from the system. The neutrino luminosity may exceed the Blandford-Znajek luminosity of the polar jets and the subsequent annihilation of neutrino-antineutrino pairs will provide an additional source of power to the GRB emission.
BACKSCATTERING BY NON-SPHERICAL NATURAL PARTICLES: INSTRUMENT DEVELOPMENT, IOP'S,
Boss, Emmanuel S.
of the proposed instrument. Figure 1: Engineering view of the self-contained battery powered instrument. In light-spherical effects on backscatter. b. Characterization of scattering from terrigenous and biological size-sorted non
Water adsorption on aggregates of spherical aerosol nano particles
Nie, Chu
2005-11-01T23:59:59.000Z
A three dimensional integral equation is developed in order to compute water adsorption onto aggregates of spherical aerosol nano particles. The integral equation is derived from molecular density functional theory, with a weighted density...
Elastic–Plastic Spherical Contact Modeling Including Roughness Effects
Li, L.; Etsion, I.; Talke, F. E.
2010-01-01T23:59:59.000Z
A multilevel model for elastic–plastic contact between ajunction growth of an elastic–plastic spherical contact. J.nite element based elastic–plastic model for the contact of
Villone, F.; Mastrostefano, S. [Euratom-ENEA-CREATE Ass., DIEI, Univ. di Cassino e Lazio Merid., Cassino (Italy); Calabrò, G.; Vlad, G.; Crisanti, F.; Fusco, V. [C. R. Frascati, Euratom-ENEA Ass., Via E. Fermi 45, 00044 Frascati (Italy); Marchiori, G.; Bolzonella, T.; Marrelli, L.; Martin, P. [Cons. RFX, Euratom-ENEA-RFX Ass., Corso Stati Uniti 4, 35127 Padova (Italy); Liu, Y. Q. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Mantica, P. [IFP-CNR, Euratom-ENEA-CNR Ass. Via Cozzi 53, 20125 Milano (Italy)
2014-08-15T23:59:59.000Z
One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To this purpose, a new FAST scenario has then been designed at I{sub p}?=?10 MA, B{sub T}?=?8.5?T, q{sub 95}???2.3. Transport simulations, carried out by using the code JETTO and the first principle transport model GLF23, indicate that, under these conditions, FAST could achieve an equivalent Q???3.5. FAST will be equipped with a set of internal active coils for feedback control, which will produce magnetic perturbation with toroidal number n?=?1 or n?=?2. Magnetohydrodynamic (MHD) mode analysis and feedback control simulations performed with the codes MARS, MARS-F, CarMa (both assuming the presence of a perfect conductive wall and using the exact 3D resistive wall structure) show the possibility of the FAST conductive structures to stabilize n?=?1 ideal modes. This leaves therefore room for active mitigation of the resistive mode (down to a characteristic time of 1?ms) for safety purposes, i.e., to avoid dangerous MHD-driven plasma disruption, when working close to the machine limits and magnetic and kinetic energy density not far from reactor values.
Confinement of pure electron plasmas in the Columbia Non-neutral Torus
Berkery, John W.; Pedersen, Thomas Sunn; Kremer, Jason P.; Marksteiner, Quinn R.; Lefrancois, Remi G.; Hahn, Michael S.; Brenner, Paul W. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
2007-06-15T23:59:59.000Z
The Columbia Non-neutral Torus (CNT) [T. S. Pedersen, J. P. Kremer, R. G. Lefrancois, Q. Marksteiner, N. Pomphrey, W. Reiersen, F. Dahlgreen, and X. Sarasola, Fusion Sci. Technol. 50, 372 (2006)] is a stellarator used to study non-neutral plasmas confined on magnetic surfaces. A detailed experimental study of confinement of pure electron plasmas in CNT is described here. Electrons are introduced into the magnetic surfaces by placing a biased thermionic emitter on the magnetic axis. As reported previously, the insulated rods holding this and other emitter filaments contribute to the radial transport by charging up negatively and creating ExB convective transport cells. A model for the rod-driven transport is presented and compared to the measured transport rates under a number of different conditions, finding good agreement. Neutrals also drive transport, and by varying the neutral pressure in the experiment, the effects of rod-driven and neutral-driven transport are separated. The neutral-driven electron loss rate scales linearly with neutral pressure. The neutral driven transport, presumably caused by electron-neutral collisions, is much greater than theoretical estimates for neoclassical diffusion in a classical stellarator with strong radial electric fields. In fact the confinement time is on the order of the electron-neutral collision time. Ion accumulation, electron attachment, and other effects are considered, but do not explain the observed transport rates.
CHARACTERIZATION OF CYCLED SPHERICAL RESORCINOL-FORMALDEHYDE ION EXCHANGE RESIN
Nash, C.; Duignan, M.
2010-02-23T23:59:59.000Z
This report presents characterization data for two spherical resorcinol-formaldehyde (sRF) resin beds that had processed cesium in non-radioactive and radioactive cycles. All column cycle operations for the resin beds including loading, displacements, elution, regeneration, breakthroughs, and solution analyses are reported in Nash and Duignan, 2009a. That report covered four ion exchange (IX) campaigns using the two {approx}11 mL beds in columns in a lead-lag arrangement. The first two campaigns used Savannah River Site (SRS) Tank 2F nonradioactive simulant while the latter two were fed with actual dissolved salt in the Savannah River National Laboratory (SRNL) Shielded Cells. Both radioactive cycles ran to cesium breakthrough of the lead column. The resin beds saw in excess of 400 bed volumes of feed in each cycle. Resin disposal plans in tank farm processing depend on characterizations of resin used with actual tank feed. Following a final 30 bed volume (BV) elution with nitric acid, the resin beds were found to contain detectable chromium, barium, boron, aluminum, iron, sodium, sulfur, plutonium, cesium, and mercury. Resin affinity for plutonium is important in criticality safety considerations. Cesium-137 was found to be less than 10E+7 dpm/g of resin, similar to past work with sRF resin. Sulfur levels are reasonably consistent with other work and are expected to represent sulfur chemistry used in the resin manufacture. There were low but detectable levels of technetium, americium, and curium. Toxicity Characteristic Leaching Procedure (TCLP) work on the used (eluted) resin samples showed significant contents of mercury, barium, and chromium. One resin sample exceeded the TCLP level for mercury while the other metals were below TCLP levels. TCLP organics measurements indicated measurable benzene in one case, though the source was unknown. Results of this work were compared with other work on similar sRF resin characterizations in this report. This is the first work to quantify mercury on sRF resin. Resin mercury content is important in plans for the disposition of used sRF resin. Mercury speciation in high level waste (HLW) is unknown. It may be partly organic, one example being methyl mercury cation. Further study of the resin's affinity for mercury is recommended.
Method to produce large, uniform hollow spherical shells
Hendricks, C.D.
1983-09-26T23:59:59.000Z
The invention is a method to produce large uniform hollow spherical shells by (1) forming uniform size drops of heat decomposable or vaporizable material, (2) evaporating the drops to form dried particles, (3) coating the dried particles with a layer of shell forming material and (4) heating the composite particles to melt the outer layer and to decompose or vaporize the inner particle to form an expanding inner gas bubble. The expanding gas bubble forms the molten outer layer into a shell of relatively large diameter. By cycling the temperature and pressure on the molten shell, nonuniformities in wall thickness can be reduced. The method of the invention is utilized to produce large uniform spherical shells, in the millimeter to centimeter diameter size range, from a variety of materials and of high quality, including sphericity, concentricity and surface smoothness, for use as laser fusion or other inertial confinement fusion targets as well as other applications.
Collective neutrino oscillations in non-spherical geometry
Basudeb Dasgupta; Amol Dighe; Alessandro Mirizzi; Georg G. Raffelt
2008-05-21T23:59:59.000Z
The rich phenomenology of collective neutrino oscillations has been studied only in one-dimensional or spherically symmetric systems. Motivated by the non-spherical example of coalescing neutron stars, presumably the central engines of short gamma-ray bursts, we use the Liouville equation to formulate the problem for general source geometries. Assuming the neutrino ensemble displays self-maintained coherence, the problem once more becomes effectively one-dimensional along the streamlines of the overall neutrino flux. This approach for the first time provides a formal definition of the ``single-angle approximation'' frequently used for supernova neutrinos and allows for a natural generalization to non-spherical geometries. We study the explicit example of a disk-shaped source as a proxy for coalescing neutron stars.
The analysis and optimization of a spherical silicon solar cell
McKee, William Randall
1976-01-01T23:59:59.000Z
THE ANALYSIS AND OPTIMIZATION OF A SPHERICAL SILICON SOLAR CELL A Thesis by William Randall McKee /'' Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... August 1976 Ma]or Subject: Electrical Engineering THE ANALYSIS AND OPTIMIZATION OF A SPHERICAL SILICON SOLAR CELL A Thesis by William Randall McKee Approved as to style and content by: (Chai. rman of Committee) (H of D partment) (Member) 2D...
The analysis and optimization of a spherical silicon solar cell
McKee, William Randall
1976-01-01T23:59:59.000Z
THE ANALYSIS AND OPTIMIZATION OF A SPHERICAL SILICON SOLAR CELL A Thesis by William Randall McKee /'' Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... August 1976 Ma]or Subject: Electrical Engineering THE ANALYSIS AND OPTIMIZATION OF A SPHERICAL SILICON SOLAR CELL A Thesis by William Randall McKee Approved as to style and content by: (Chai. rman of Committee) (H of D partment) (Member) 2D...
Spherical cloaking using multilayer shells of ordinary dielectrics
Wang, Xiaohui; Chen, Fang; Semouchkina, Elena, E-mail: esemouch@mtu.edu [Department of Electrical and Computer Engineering, Michigan Technological University, Houghton, MI, 49931 (United States)] [Department of Electrical and Computer Engineering, Michigan Technological University, Houghton, MI, 49931 (United States)
2013-11-15T23:59:59.000Z
An approach for spherical cloaking using multilayer ordinary dielectric materials has been developed. The total scattering cross section (TSCS) of the spherical multilayer shell with metallic core was derived based on the Mie theory. The dielectric profile of the shell was optimized to minimize the TSCS of the cloaked target. The specific directions, at which the scattering could be practically eliminated, were detected. The influence of the target size and the dielectric material loss on the cloaking efficiency was analyzed. It was shown that the cloaking efficiency for larger targets could be improved by employing lossy materials in the shell.
Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Heidelberger, Philip; Senger, Robert M; Salapura, Valentina; Steinmacher-Burow, Burkhard; Sugawara, Yutaka; Takken, Todd E
2013-08-27T23:59:59.000Z
Embodiments of the invention provide a method, system and computer program product for embedding a global barrier and global interrupt network in a parallel computer system organized as a torus network. The computer system includes a multitude of nodes. In one embodiment, the method comprises taking inputs from a set of receivers of the nodes, dividing the inputs from the receivers into a plurality of classes, combining the inputs of each of the classes to obtain a result, and sending said result to a set of senders of the nodes. Embodiments of the invention provide a method, system and computer program product for embedding a collective network in a parallel computer system organized as a torus network. In one embodiment, the method comprises adding to a torus network a central collective logic to route messages among at least a group of nodes in a tree structure.
Dynamics of multiple double layers in high pressure glow discharge in a simple torus
Kumar Paul, Manash, E-mail: manashkr@gmail.com [Department of Physics, National Institute of Technology Agartala, Tripura–799 046 (India); Sharma, P. K.; Thakur, A.; Kulkarni, S. V.; Bora, D. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat–382 428 (India)
2014-06-15T23:59:59.000Z
Parametric characterization of multiple double layers is done during high pressure glow discharge in a toroidal vessel of small aspect ratio. Although glow discharge (without magnetic field) is known to be independent of device geometry, but the toroidal boundary conditions are conducive to plasma growth and eventually the plasma occupy the toroidal volume partially. At higher anode potential, the visibly glowing spots on the body of spatially extended anode transform into multiple intensely luminous spherical plasma blob structures attached to the tip of the positive electrode. Dynamics of multiple double layers are observed in argon glow discharge plasma in presence of toroidal magnetic field. The radial profiles of plasma parameters measured at various toroidal locations show signatures of double layer formation in our system. Parametric dependence of double layer dynamics in presence of toroidal magnetic field is presented here.
Wilkinson, Michael
for Quantum Chaos on a Torus Itzhack Dana,1 Mario Feingold,2 and Michael Wilkinson3 1 Department of Physics in the field of quantum chaos, can be reduced to a torus, either in configuration space (e.g., the Sinai in the quantum-chaos literature [4Â12], although attention has often been confined to strict periodicity. General
A. -C. Donea; R. J. Protheroe
2002-02-04T23:59:59.000Z
The radiation fields external to the jets and originating from within a few parsecs from the black hole, are discussed in this paper. They are the direct radiation from an accretion disk in symbiosis with jets, the radiation field from the broad line region (BLR) surrounding the accretion disk, and the infrared radiation from a dusty torus. The jet/disk symbiosis modifies the energetics in the central parsec of AGN such that for a given accretion rate, a powerful jet would occur at the expense of the disk luminosity, and consequently the disk would less efficiently ionize the BRL clouds or heat the dust in the torus, thereby affecting potentially important target photon fields for interactions of gamma-rays, accelerated electrons and protons along the jet. Motivated by unification schemes of active galactic nuclei, we briefly review the evidence for the existence of broad line regions and small-scale dust tori in BL Lacs and Fanaroff-Riley Class I (FR-I) radio galaxies. We propose that an existing jet-accretion disk symbiosis can be extrapolated to provide a large scale-symbiosis between other important dusty constituents of the blazar/FR-I family. In the present paper, we discuss in the context of this symbiosis interactions of GeV and TeV gamma-rays produced in the jet with the various radiation fields external to the jet in quasars and blazars, taking account the anisotropy of the radiation.
Ghoshal, P. K. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pastor, O. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Kashy, D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Schneider, W. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wiseman, M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zarecky, M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Young, G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rode, C. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Elouadrhiri, L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Burkert, V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2014-12-18T23:59:59.000Z
The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coil case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses were limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ghoshal, Probir K.; Pastor, Orlando; Kashy, David H.; Schneider, William J.; Wiseman, Mark A.; Zarecky, Michael R.; Young, Glenn R.; Rode, Claus H.; Elouadrhiri, Latifa; Burkert, Volker D.
2015-06-01T23:59:59.000Z
The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coilmore »case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses were limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.« less
Etheridge, A M
2011-01-01T23:59:59.000Z
We extend the spatial Lambda-Fleming-Viot process introduced in [BEV10] to incorporate recombination. The process models allele frequencies in a population which is distributed over the two-dimensional torus T(L) of sidelength L and is subject to two kinds of reproduction events : small events of radius O(1) and much rarer large events of radius O(L^{alpha}) for some alpha in (0,1]. We investigate the correlation between the times to the most recent common ancestor of alleles at two linked loci for a sample of size two from the population. These individuals are initially sampled from `far apart' on the torus. As L tends to infinity, depending on the frequency of the large events, the recombination rate and the initial distance between the two individuals sampled, we obtain either a complete decorrelation of the coalescence times at the two loci, or a sharp transition between a first period of complete correlation and a subsequent period during which the remaining times needed to reach the most recent common a...
The method of planes pressure tensor for a spherical subvolume
Heyes, D. M., E-mail: d.heyes@imperial.ac.uk; Smith, E. R., E-mail: edward.smith05@imperial.ac.uk; Dini, D., E-mail: d.dini@imperial.ac.uk; Zaki, T. A., E-mail: t.zaki@imperial.ac.uk [Department of Mechanical Engineering, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ (United Kingdom)
2014-02-07T23:59:59.000Z
Various formulas for the local pressure tensor based on a spherical subvolume of radius, R, are considered. An extension of the Method of Planes (MOP) formula of Todd et al. [Phys. Rev. E 52, 1627 (1995)] for a spherical geometry is derived using the recently proposed Control Volume formulation [E. R. Smith, D. M. Heyes, D. Dini, and T. A. Zaki, Phys. Rev. E 85, 056705 (2012)]. The MOP formula for the purely radial component of the pressure tensor is shown to be mathematically identical to the Radial Irving-Kirkwood formula. Novel offdiagonal elements which are important for momentum conservation emerge naturally from this treatment. The local pressure tensor formulas for a plane are shown to be the large radius limits of those for spherical surfaces. The radial-dependence of the pressure tensor computed by Molecular Dynamics simulation is reported for virtual spheres in a model bulk liquid where the sphere is positioned randomly or whose center is also that of a molecule in the liquid. The probability distributions of angles relating to pairs of atoms which cross the surface of the sphere, and the center of the sphere, are presented as a function of R. The variance in the shear stress calculated from the spherical Volume Averaging method is shown to converge slowly to the limiting values with increasing radius, and to be a strong function of the number of molecules in the simulation cell.
Møller energy of the nonstatic spherically symmetric metrics
S. S. Xulu
2000-10-19T23:59:59.000Z
The energy distribution in the most general nonstatic spherically symmetric space-time is obtained using M{\\o}ller's energy-momentum complex. This result is compared with the energy expression obtained by using the energy-momentum complex of Einstein. Some examples of energy distributions in different prescriptions are discussed.
Novel spherical hohlraum with cylindrical laser entrance holes and shields
Lan, Ke [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zheng, Wudi [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
2014-09-15T23:59:59.000Z
Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles?>?45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums.
Multivariate Tests Based on Left-Spherically Distributed Linear Scores
Magdeburg, UniversitÃ¤t
Multivariate Tests Based on Left-Spherically Distributed Linear In this paper, a method for multivariate testing based on low-dimensional, data- dependent, linear scores approaches. In a natural way, standard problems of multivari- ate analysis thus induce the occurrence
Electrical Characterization of Spherical Micro Solar Cell module from Kyosemi
BILAG 2 Electrical Characterization of Spherical Micro Solar Cell module from Kyosemi Søren Poulsen sensitive to shadows than traditional PV-modules due to interconnection of the individual cells in numerous voltage-current curve followed by a correction to standard test conditions (STC: 1000 W/m2 , 25°C cell
The Complete Flux Scheme for Spherically Symmetric Conservation Laws
Eindhoven, Technische Universiteit
and M.J.H. Anthonissen Eindhoven University of Technology Department of Mathematics and Computer Science for computing the numerical fluxes. The approximation for the flux is based on the complete differential to a spherically symmet- ric conservation law of advection-diffusion-reaction type. For the numer- ical flux we use
Spherical Domain Wall Collapse in a Dust Universe
Norihiro Tanahashi; Chul-Moon Yoo
2015-05-13T23:59:59.000Z
To clarify observational consequence of bubble nucleations in inflationary era, we analyse dynamics of a spherical domain wall in an expanding universe. We consider a spherical shell of the domain wall with tension $\\sigma$ collapsing in a spherically-symmetric dust universe, which is initially separated into the open Friedmann-Lema\\^itre-Robertson-Walker universe inside the shell and the Einstein-de Sitter universe outside. The domain wall shell collapses due to the tension, and sweeps the dust fluid. The universe after the collapse becomes inhomogeneous and is described by the Lema\\^itre-Tolman-Bondi model. We construct solutions describing this inhomogeneous universe by solving dynamical equations obtained from Israel's junction conditions applied to this system. We find that a black hole forms after the domain wall collapse for any initial condition, and that the black hole mass at the moment of its formation is universally given by $M_{\\rm BH}\\simeq 17 \\sigma/H_{\\rm hc}$, where $H_{\\rm hc}$ is the Hubble parameter at the time when the shell radius becomes equal to the Hubble radius. We also find that the dust fluid is distributed as $\\rho\\propto R^{3/2}$ near the central region after the collapse, where $R$ is the area radius. These features would provide observable signatures of a spherical domain wall generated in the early universe.
Thermochemical structures within a spherical mantle: Superplumes or piles?
Zhong, Shijie
Thermochemical structures within a spherical mantle: Superplumes or piles? Allen K. Mc interpreted as being either piles or superplumes of dense material. We perform numerical modeling a dense chemical component into a small number of isolated, rounded piles or superplumes of material. We
Spherical radon transforms and mathematical problems of thermoacoustic tomography
Ambartsoumian, Gaik
2009-06-02T23:59:59.000Z
The spherical Radon transform (SRT) integrates a function over the set of all spheres with a given set of centers. Such transforms play an important role in some newly developing types of tomography as well as in several areas of mathematics...
Stability and superluminality of spherical DBI Galileon solutions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Goon, Garrett L.; Hinterbichler, Kurt; Trodden, Mark
2011-04-12T23:59:59.000Z
We showed that, when considered as local modifications to gravity, such as in the solar system, there exists a region of parameter space in which spherically symmetric static solutions to a particular class of modified gravity theories exist and are stable.
Separating expansion from contraction and generalizing TOV condition in spherically
Paris-Sud XI, UniversitÃ© de
example of perturbed -CDM models. We adopt the Generalised PainlevÃ©-Gullstrand (hereafter GPG) formalism invariants kinematic quantities [6]. ADM APPROACH TO LTB MODELS IN GPG SYSTEM We consider a spherically. Performing an ADM 3+1 splitting in the GPG coordinates [5] , the metric reads ds2 = -(t,r)2 dt2 + 1 1+E
ABAREX: A neutron spherical optical-statistical model code
Lawson, R.D.
1992-06-01T23:59:59.000Z
The spherical optical-statistical model is briefly reviewed and the capabilities of the neutron scattering code, ABAREX, are presented. Input files for ten examples, in which neutrons are scattered by various nuclei, are given and the output of each run is discussed in detail.
Spherical radon transforms and mathematical problems of thermoacoustic tomography
Ambartsoumian, Gaik
2009-06-02T23:59:59.000Z
The spherical Radon transform (SRT) integrates a function over the set of all spheres with a given set of centers. Such transforms play an important role in some newly developing types of tomography as well as in several areas of mathematics...
Masao Iwamatsu
2015-06-19T23:59:59.000Z
Line-tension-induced {scenario of heterogeneous nucleation} is studied for a lens-shaped nucleus with a finite contact angle nucleated on a spherical substrate and on the bottom of the wall of a spherical cavity. The effect of line tension on the free energy of a critical nucleus can be separated from the usual volume term. By comparing the free energy of a lens-shaped critical nucleus of a finite contact angle with that of a spherical nucleus, we find that a spherical nucleus may have a lower free energy than a lens-shaped nucleus when the line tension is positive and large, which is similar to the drying transition predicted by Widom [B. Widom, J. Phys. Chem. {\\bf 99} 2803 (1995)]. Then, the homogeneous nucleation rather than the heterogeneous nucleation will be favorable. Similarly, the free energy of a lens-shaped nucleus becomes negative when the line tension is negative and large. Then, the barrier-less nucleation with no thermal activation called athermal nucleation will be realized.
Patterns of convection in rotating spherical R Simitev and F H Busse
Simitev, Radostin D
Patterns of convection in rotating spherical shells R Simitev and F H Busse Institute of Physics of rotating spherical shells. For recent reviews we refer to the papers by Zhang and Busse [23] and Busse [6
Harris, Matthew Wade
2007-09-17T23:59:59.000Z
This analytical model predicts the stress concentration around an elastic, spherical particle in an elastic-plastic metal matrix using strain gradient plasticity theory and a finite unit cell. The model reduces to the special case with a spherical...
Castillo, Davis
2011-08-08T23:59:59.000Z
. The spherical anemometer introduced by the German researcher Holling presents the opportunity to incorporate the theoretical cantilevered Euler-Bernoulli beam with a spherical mass tip to develop a deflection and wind relationship driven by cross...
Luciano Rezzolla; Luca Baiotti; Bruno Giacomazzo; David Link; Jose A. Font
2010-05-13T23:59:59.000Z
We present new results from accurate and fully general-relativistic simulations of the coalescence of unmagnetized binary neutron stars with various mass ratios. The evolution of the stars is followed through the inspiral phase, the merger and prompt collapse to a black hole, up until the appearance of a thick accretion disk, which is studied as it enters and remains in a regime of quasi-steady accretion. Although a simple ideal-fluid equation of state with \\Gamma=2 is used, this work presents a systematic study within a fully general relativistic framework of the properties of the resulting black-hole--torus system produced by the merger of unequal-mass binaries. More specifically, we show that: (1) The mass of the torus increases considerably with the mass asymmetry and equal-mass binaries do not produce significant tori if they have a total baryonic mass M_tot >~ 3.7 M_sun; (2) Tori with masses M_tor ~ 0.2 M_sun are measured for binaries with M_tot ~ 3.4 M_sun and mass ratios q ~ 0.75-0.85; (3) The mass of the torus can be estimated by the simple expression M_tor(q, M_tot) = [c_1 (1-q) + c_2](M_max-M_tot), involving the maximum mass for the binaries and coefficients constrained from the simulations, and suggesting that the tori can have masses as large as M_tor ~ 0.35 M_sun for M_tot ~ 2.8 M_sun and q ~ 0.75-0.85; (4) Using a novel technique to analyze the evolution of the tori we find no evidence for the onset of non-axisymmetric instabilities and that very little, if any, of their mass is unbound; (5) Finally, for all the binaries considered we compute the complete gravitational waveforms and the recoils imparted to the black holes, discussing the prospects of detection of these sources for a number of present and future detectors.
Dynamic Spherical Volumetric Simplex Splines with Applications in Biomedicine Wayne State University
Qin, Hong
Dynamic Spherical Volumetric Simplex Splines with Applications in Biomedicine Yunhao Tan , Jing Hua computational framework based on dy- namic spherical volumetric simplex splines for simulation of genus- zero to reconstruct the high-fidelity digi- tal model of a real-world object with spherical volumetric simplex splines
Basic Routines for the Rank2k Update: 2D Torus vs Reconfigurable Network
Desprez, Frédéric
by the National Science Foundation Science and Technology Center Cooperative Agreement No. CCR8809615, CNRS Center Cooperative Agreement CCR8809615, the DARPA and ARO under contract DAAL0391C0047, PRC C 3 , CNRSNSF grant 950.223/07, Archipel SA and MRE under grant 974, and DRET. 1 #12; interconnection
Global oscillations of a fluid torus as a modulation mechanism for black-hole high-frequency QPOs
Michal Bursa
2005-10-15T23:59:59.000Z
We study strong-gravity effects on modulation of radiation emerging from accreting compact objects as a possible mechanism for flux modulation in QPOs. We construct a toy model of an oscillating torus in the slender approximation assuming thermal bremsstrahlung for the intrinsic emissivity of the medium and we compute observed (predicted) radiation signal including contribution of indirect (higher-order) images and caustics in the Schwarzschild spacetime. We show that the simplest oscillation mode in an accretion flow, axisymmetric up-and-down motion at the meridional epicyclic frequency, may be directly observable when it occurs in the inner parts of accretion flow around black holes. Together with the second oscillation mode, an in-and-out motion at the radial epicyclic frequency, it may then be responsible for the high-frequency modulations of the X-ray flux observed at two distinct frequencies (twin HF-QPOs) in micro-quasars.
Relativistic electromagnetic mass models in spherically symmetric spacetime
S. K. Maurya; Y. K. Gupta; Saibal Ray; Vikram Chatterjee
2015-07-04T23:59:59.000Z
Under the static spherically symmetric Einstein-Maxwell spacetime of embedding class one we explore possibility of electromagnetic mass model where mass and other physical parameters have purely electromagnetic origin (Tiwari 1984, Gautreau 1985, Gron 1985). This work is in continuation of our earlier investigation (Maurya 2015a) where we developed an algorithm and found out three new solutions of electromagnetic mass models. In the present letter we consider different metric potentials $\
Dust Static Spherically Symmetric Solution in $f(R)$ Gravity
Muhammad Sharif; Hafiza Rizwana Kausar
2011-02-21T23:59:59.000Z
In this paper, we take dust matter and investigate static spherically symmetric solution of the field equations in metric f(R) gravity. The solution is found with constant Ricci scalar curvature and its energy distribution is evaluated by using Landau-Lifshitz energy-momentum complex. We also discuss the stability condition and constant scalar curvature condition for some specific popular choices of f(R) models in addition to their energy distribution.
Self-similar spherical shock solution with sustained energy injection
V. I. Dokuchaev
2002-09-20T23:59:59.000Z
We present the generalization of the Sedov-Taylor self-similar strong spherical shock solution for the case of a central energy source varying in time, $E=A t^k$, where $A$ and $k$ are constants. The known Sedov-Taylor solution corresponds to a particular adiabatic case of $k=0$ or \\emph{instant shock} with an instant energy source of the shock, $E=A$. The self-similar hydrodynamic flow in the nonadiabatic $k\
Spherical Resorcinol-Formaldehyde Synthesis by Inverse Suspension Polymerization
Ray, Robert J.; Scrivens, Walter A.; Nash, Charles
2005-10-21T23:59:59.000Z
Base catalyzed sol-gel polycondensation of resorcinol (1,3-dihydroxybenzene) with formaldehyde by inverse suspension polymerization leads to the formation of uniform, highly cross-linked, translucent, spherical gels, which have increased selectivity and capacity for cesium ion removal from high alkaline solutions. Because of its high selectivity for cesium ion, resorcinol-formaldehyde (R-F) resins are being considered for process scale column radioactive cesium removal by ion-exchange at the Waste Treatment and Immobilization Plant (WTP), which is now under construction at the Hanford site. Other specialty resins such as Superlig{reg_sign} 644 have been ground and sieved and column tested for process scale radioactive cesium removal but show high pressure drops across the resin bed during transition from column regeneration to loading and elution. Furthermore, van Deemter considerations indicate better displacement column chromatography by the use of spherical particle beads rather than irregularly shaped ground or granular particles. In our studies batch contact equilibrium experiments using a high alkaline simulant show a definite increase in cesium loading onto spherical R-F resin. Distribution coefficient (Kd) values ranged from 777 to 429 mL/g in the presence of 0.1M and 0.7M potassium ions, respectively. Though other techniques for making R-F resins have been employed, to our knowledge no one has made spherical R-F resins by inverse suspension polymerization. Moreover, in this study we discuss the data comparisons to known algebraic isotherms used to evaluate ion-exchange resins for WTP plant scale cesium removal operations.
TDHF fusion calculations for spherical+deformed systems
A. S. Umar; V. E. Oberacker
2006-04-04T23:59:59.000Z
We outline a formalism to carry out TDHF calculations of fusion cross sections for spherical + deformed nuclei. The procedure incorporates the dynamic alignment of the deformed nucleus into the calculation of the fusion cross section. The alignment results from multiple E2/E4 Coulomb excitation of the ground state rotational band. Implications for TDHF fusion calculations are discussed. TDHF calculations are done in an unrestricted three-dimensional geometry using modern Skyrme force parametrizations.
Spherically Symmetric Solutions to Fourth-Order Theories of Gravity
T. Clifton
2006-11-10T23:59:59.000Z
Gravitational theories generated from Lagrangians of the form f(R) are considered. The spherically symmetric solutions to these equations are discussed, paying particular attention to features that differ from the standard Schwarzschild solution. The asymptotic form of solutions is described, as is the lack of validity of Birkhoff's theorem. Exact solutions are presented which illustrate these points and their stability and geodesics are investigated.
Global energy conservation in nonlinear spherical characteristic evolutions
W. Barreto
2014-04-20T23:59:59.000Z
Associated to the unique 4-parametric subgroup of translations, normal to the Bondi-Metzner-Sachs group, there exists a generator of the temporal translation asymptotic symmetry. Such a descriptor of the motion along the conformal orbit near null infinity is propagated to finite regions. This allows us to observe the global energy conservation even in extreme situations near the critical behavior of the massless scalar field collapse in spherical symmetry.
) or DT fill, launching a strong converging shock that reaches 2 Gbar after rebound. The physics-ray ablation to transfer energy to a much thicker capsule rather than direct laser isochoric heating of a very
Method for preparing spherical ferrite beads and use thereof
Lauf, Robert J. (Oak Ridge, TN); Anderson, Kimberly K. (Knoxville, TN); Montgomery, Frederick C. (Oak Ridge, TN); Collins, Jack L. (Knoxville, TN)
2002-01-01T23:59:59.000Z
The invention allows the fabrication of small, dense, highly polished spherical beads of hexagonal ferrites with selected compositions for use in nonreciprocal microwave and mm-wave devices as well as in microwave absorbent or reflective coatings, composites, and the like. A porous, generally spherical bead of hydrous iron oxide is made by a sol-gel process to form a substantially rigid bead having a generally fine crystallite size and correspondingly finely distributed internal porosity. The resulting gel bead is washed and hydrothermally reacted with a soluble alkaline earth salt (typically Ba or Sr) under conditions of elevated temperature and pressure to convert the bead into a mixed hydrous iron-alkaline earth oxide while retaining the generally spherical shape. This mixed oxide bead is then washed, dried, and calcined to produce the desired (BaFe.sub.12 O.sub.19 or SrFe.sub.12 O.sub.19) crystal structure. The calcined bead is then sintered to form a dense bead of the BaFe.sub.12 O.sub.19 and SrFe.sub.12 O.sub.19 phase suitable for polishing and incorporation into various microwave devices and components.
Energy partition at the collapse of spherical cavitation bubbles
Tinguely, Marc; Kobel, Philippe; Dorsaz, Nicolaz; de Bosset, Aurele; Farhat, Mohamed
2012-01-01T23:59:59.000Z
Spherically collapsing cavitation bubbles produce a shock wave followed by a rebound bubble. Here we present a systematic investigation of the energy partition between the rebound and the shock. Highly spherical cavitation bubbles are produced in microgravity, which suppress the buoyant pressure gradient that otherwise deteriorates the sphericity of the bubbles. We measure the radius of the rebound bubble and estimate the shock energy as a function of the initial bubble radius (2-5.6 mm) and the liquid pressure (10-80 kPa). Those measurements uncover a systematic pressure dependence of the energy partition between rebound and shock. We demonstrate that these observations agree with a physical model relying on a first-order approximation of the liquid compressibility and an adiabatic treatment of the non-condensable gas inside the bubble. Using this model we find that the energy partition between rebound and shock is dictated by a single non-dimensional parameter $\\xi = \\Delta p\\gamma^6/[{p_{g0}}^{1/\\gamma} (\\...
HIPPOCAMPAL SURFACE DISCRIMINATION VIA INVARIANT DESCRIPTORS OF SPHERICAL CONFORMAL MAPS
Thompson, Paul
by the National Institutes of Health through the NIH Roadmap for Medical Research, Grant U54 RR021813 entitled
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
on the Pajarito Plateau topic of inaugural lecture at Los Alamos National Laboratory January 4, 2013 Lecture series begins yearlong commemoration of 70th anniversary LOS...
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073
to the general public from: National Technical Information Service U.S. Department of Commerce 5285 Port Royal of the computer control system for the LPI. I. INTRODUCTION The National Spherical Torus Experiment (NSTXPREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073 PRINCETON PLASMA
Physics Laboratory Status of the Control System on the National Spherical Torus Experiment (NSTX) D.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 Telephone: (865) 576-8401 Fax: (865) 576-5728 E-mail: reports@adonis.osti.gov National Technical Information
FOR APPLICATION IN THE ETE SPHERICAL TOKAMAKAPPLICATION IN THE ETE SPHERICAL TOKAMAK Luis Filipe de F. P. Wiltgen tokamak based on Artificial Neural Networks (tokamak based on Artificial Neural Networks (ANNANN).). ETEETE is ais a low aspect ratio tokamak that should operate with highly elongated plasmas, which
Spherically symmetric electromagnetic mass models of embedding class one
S. K. Maurya; Y. K. Gupta; Saibal Ray; Sourav Roy Chowdhury
2015-05-30T23:59:59.000Z
In this article we consider the static spherically symmetric spacetime metric of embedding class one. Specifically three new electromagnetic mass models are derived where the solutions are entirely dependent on the electromagnetic field, such that the physical parameters, like density, pressure etc. do vanish for the vanishing charge. We have analyzed schematically all these three sets of solutions related to electromagnetic mass models by plotting graphs and shown that they can pass through all the physical tests performed by us. To validate these special type of solutions related to electromagnetic mass models a comparison has been done with that of compact stars and shown exclusively the feasibility of the models.
Geometrodynamics in a spherically symmetric, static crossflow of null dust
Zsolt Horváth; Zoltán Kovács; László Á. Gergely
2006-10-12T23:59:59.000Z
The spherically symmetric, static spacetime generated by a crossflow of non-interacting radiation streams, treated in the geometrical optics limit (null dust) is equivalent to an anisotropic fluid forming a radiation atmosphere of a star. This reference fluid provides a preferred / internal time, which is employed as a canonical coordinate. Among the advantages we encounter a new Hamiltonian constraint, which becomes linear in the momentum conjugate to the internal time (therefore yielding a functional Schr\\"{o}dinger equation after quantization), and a strongly commuting algebra of the new constraints.
Geometrodynamics in a spherically symmetric, static crossflow of null dust
Horváth, Z; Kovács, Z; Horv\\'{a}th, Zsolt; Kov\\'{a}cs, Zolt\\'{a}n
2006-01-01T23:59:59.000Z
The spherically symmetric, static spacetime generated by a crossflow of non-interacting radiation streams, treated in the geometrical optics limit (null dust) is equivalent to an anisotropic fluid forming a stellar atmosphere. This reference fluid provides a preferred / internal time, which is employed as a canonical coordinate. Among the advantages we encounter a new Hamiltonian constraint, which becomes linear in the momentum conjugate to the internal time (therefore yielding a functional Schr\\"{o}dinger equation after quantization), and a strongly commuting algebra of the new constraints.
Full light absorption in single arrays of spherical nanoparticles
Ra'di, Y; Kosulnikov, S U; Omelyanovich, M M; Morits, D; Osipov, A V; Simovski, C R; Tretyakov, S A
2015-01-01T23:59:59.000Z
In this paper we show that arrays of core-shell nanoparticles function as effective thin absorbers of light. In contrast to known metamaterial absorbers, the introduced absorbers are formed by single planar arrays of spherical inclusions and enable full absorption of light incident on either or both sides of the array. We demonstrate possibilities for realizing different kinds of symmetric absorbers, including resonant, ultra-broadband, angularly selective, and all-angle absorbers. The physical principle behind these designs is explained considering balanced electric and magnetic responses of unit cells. Photovoltaic devices and thermal emitters are the two most important potential applications of the proposed designs.
The 2m <= r property of spherically symmetric static spacetimes
Marc Mars; M. M. Martin-Prats; Jose M. M. Senovilla
2002-02-01T23:59:59.000Z
We prove that all spherically symmetric static spacetimes which are both regular at r=0 and satisfying the single energy condition rho + p_r + p_t >= 0 cannot contain any black hole region (equivalently, they must satisfy 2m/r <= 1 everywhere). This result holds even when the spacetime is allowed to contain a finite number of matching hypersurfaces. This theorem generalizes a result by Baumgarte and Rendall when the matter contents of the space-time is a perfect fluid and also complements their results in the general non-isotropic case.
A non-conforming 3D spherical harmonic transport solver
Van Criekingen, S. [Commissariat a l'Energie Atomique CEA-Saclay, DEN/DM2S/SERMA/LENR Bat 470, 91191 Gif-sur-Yvette, Cedex (France)
2006-07-01T23:59:59.000Z
A new 3D transport solver for the time-independent Boltzmann transport equation has been developed. This solver is based on the second-order even-parity form of the transport equation. The angular discretization is performed through the expansion of the angular neutron flux in spherical harmonics (PN method). The novelty of this solver is the use of non-conforming finite elements for the spatial discretization. Such elements lead to a discontinuous flux approximation. This interface continuity requirement relaxation property is shared with mixed-dual formulations such as the ones based on Raviart-Thomas finite elements. Encouraging numerical results are presented. (authors)
Spherical thin-shell wormholes and modified Chaplygin gas
Sharif, M.; Azam, M., E-mail: msharif.math@pu.edu.pk, E-mail: azammath@gmail.com [Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590 (Pakistan)
2013-05-01T23:59:59.000Z
The purpose of this paper is to construct spherical thin-shell wormhole solutions through cut and paste technique and investigate the stability of these solutions in the vicinity of modified Chaplygin gas. The Darmois-Israel formalism is used to formulate the stresses of the surface concentrating the exotic matter. We explore the stability of the wormhole solutions by using the standard potential method. We conclude that there exist more stable as well as unstable solutions than the previous study with generalized Chaplygin gas [19].
Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes
Benrong Mu; Peng Wang; Haitang Yang
2015-01-24T23:59:59.000Z
In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.
Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes
Mu, Benrong; Yang, Haitang
2015-01-01T23:59:59.000Z
In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.
Large scale properties in turbulent spherically symmetric accretion
Arnab K. Ray; J. K. Bhattacharjee
2005-10-05T23:59:59.000Z
The role of turbulence in a spherically symmetric accreting system has been studied on very large spatial scales of the system. This is also a highly subsonic flow region and here the accreting fluid has been treated as nearly incompressible. It has been shown here that the coupling of the mean flow and the turbulent fluctuations, gives rise to a scaling relation for an effective "turbulent viscosity". This in turn leads to a dynamic scaling for sound propagation in the accretion process. As a consequence of this scaling, the sonic horizon of the transonic inflow solution is shifted inwards, in comparison with the inviscid flow.
Spherical Wave Propagation in a Nonlinear Elastic Medium
Korneev, Valeri A.
2009-07-01T23:59:59.000Z
Nonlinear propagation of spherical waves generated by a point-pressure source is considered for the cases of monochromatic and impulse primary waveforms. The nonlinear five-constant elastic theory advanced by Murnaghan is used where general equations of motion are put in the form of vector operators, which are independent of the coordinate system choice. The ratio of the nonlinear field component to the primary wave in the far field is proportional to ln(r) where r is a propagation distance. Near-field components of the primary field do not contribute to the far field of nonlinear component.
Spherical geodesic mesh generation (Conference) | SciTech Connect
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect JournalPentoxide.Conference: to(Conference)(TechnicalBeamsLongitudinalSpherical geodesic mesh
Spherical Accretion onto Neutron Stars Revisited: Are Hot Solutions Possible ?
Roberto Turolla; Luca Zampieri; Monica Colpi; Aldo Treves
1994-02-21T23:59:59.000Z
Stationary, spherical accretion onto an unmagnetized neutron star is here reconsidered on the wake of the seminal paper by Zel'dovich \\& Shakura (1969). It is found that new ``hot'' solutions may exist for a wide range of luminosities. These solutions are characterized by a high temperature, $10^{9}\\div 10^{11}$ K, and arise from a stationary equilibrium model where the dominant radiative mechanisms are multiple Compton scattering and bremsstrahlung emission. For low luminosities, $\\mincir 10^{-2} \\ L_{E}$, only the ``cold'' (\\`a la Zel'dovich and Shakura) solution is present.
Asymptotics of spherical superfunctions on rank one Riemannian symmetric superspaces
Alexander Alldridge; Wolfgang Palzer
2014-11-21T23:59:59.000Z
We compute the Harish-Chandra $c$-function for a generic class of rank-one purely non-compact Riemannian symmetric superspaces $X=G/K$ in terms of Euler $\\Gamma$ functions, proving that it is meromorphic. Compared to the even case, the poles of the $c$-function are shifted into the right half-space. We derive the full asymptotic Harish-Chandra series expansion of the spherical superfunctions on $X$. In the case where the multiplicity of the simple root is an even negative number, they have a closed expression as Jacobi polynomials for an unusual choice of parameters.
Angular Momentum Mixing in a Non-spherical Color Superconductor
Bo Feng; Defu Hou; Hai-cang Ren
2007-11-28T23:59:59.000Z
We study the angular momentum mixing effects in the color superconductor with non-spherical pairing. We first clarify the concept of the angular momentum mixing with a toy model for non-relativistic and spinless fermions. Then we derive the gap equation for the polar phase of dense QCD by minimizing the CJT free energy. The solution of the gap equation consists of all angular momentum partial waves of odd parity. The corresponding free energy is found to be lower than that reported in the literature with p-wave only.
Jantzen, Robert T
2012-01-01T23:59:59.000Z
In considering the mathematical problem of describing the geodesics on a torus or any other surface of revolution, there is a tremendous advantage in conceptual understanding that derives from taking the point of view of a physicist by interpreting parametrized geodesics as the paths traced out in time by the motion of a point in the surface, identifying the parameter with the time. Considering energy levels in an effective potential for the reduced motion then proves to be an extremely useful tool in studying the behavior and properties of the geodesics. The same approach can be easily tweaked to extend to both the nonrelativistic and relativistic Kepler problems. The spectrum of closed geodesics on the torus is analogous to the quantization of energy levels in models of atoms.
Robert T. Jantzen
2012-12-26T23:59:59.000Z
In considering the mathematical problem of describing the geodesics on a torus or any other surface of revolution, there is a tremendous advantage in conceptual understanding that derives from taking the point of view of a physicist by interpreting parametrized geodesics as the paths traced out in time by the motion of a point in the surface, identifying the parameter with the time. Considering energy levels in an effective potential for the reduced motion then proves to be an extremely useful tool in studying the behavior and properties of the geodesics. The same approach can be easily tweaked to extend to both the nonrelativistic and relativistic Kepler problems. The spectrum of closed geodesics on the torus is analogous to the quantization of energy levels in models of atoms.
New second derivative theories of gravity for spherically symmetric spacetimes
Rakesh Tibrewala
2015-03-17T23:59:59.000Z
We present new second derivative, generally covariant theories of gravity for spherically symmetric spacetimes (general covariance is in the $t-r$ plane) belonging to the class where the spherically symmetric Einstein-Hilbert theory is modified by the presence of $g_{\\theta\\theta}$ dependent functions. In $3+1$ dimensional vacuum spacetimes there is three-fold infinity of freedom in constructing such theories as revealed by the presence of three arbitrary $g_{\\theta\\theta}$ dependent functions in the Hamiltonian (matter Hamiltonian also has the corresponding freedom). This result is not a contradiction to the theorem of Hojman et. al. [1] which is applicable to the full theory whereas the above conclusion is for symmetry reduced sector of the theory (which has a much reduced phase space). In the full theory where there are no special symmetries, the result of Hojman et. al. will continue to hold. In the process we also show that theories where the constraint algebra is deformed by the presence of $g_{\\theta\\theta}$ dependent functions - as is the case in the presence of inverse triad corrections in loop quantum gravity - can always be brought to the form where they obey the standard (undeformed) constraint algebra by performing a suitable canonical transformation. We prove that theories obtained after performing canonical transformation are inequivalent to the symmetry reduced general relativity and that the resulting theories fall within the purview of the theories mentioned above.
Numerical Relativity in Spherical Polar Coordinates: Off-center Simulations
Thomas W. Baumgarte; Pedro J. Montero; Ewald Müller
2015-06-03T23:59:59.000Z
We have recently presented a new approach for numerical relativity simulations in spherical polar coordinates, both for vacuum and for relativistic hydrodynamics. Our approach is based on a reference-metric formulation of the BSSN equations, a factoring of all tensor components, as well as a partially implicit Runge-Kutta method, and does not rely on a regularization of the equations, nor does it make any assumptions about the symmetry across the origin. In order to demonstrate this feature we present here several off-centered simulations, including simulations of single black holes and neutron stars whose center is placed away from the origin of the coordinate system, as well as the asymmetric head-on collision of two black holes. We also revisit our implementation of relativistic hydrodynamics and demonstrate that a reference-metric formulation of hydrodynamics together with a factoring of all tensor components avoids problems related to the coordinate singularities at the origin and on the axes. As a particularly demanding test we present results for a shock wave propagating through the origin of the spherical polar coordinate system.
Electrostatic spherically symmetric configurations in gravitating nonlinear electrodynamics
Diaz-Alonso, J.; Rubiera-Garcia, D. [LUTH, Observatoire de Paris, CNRS, , USAUniversite Paris Diderot, 5 Place Jules Janssen, 92190 Meudon (France) and Departamento de Fisica, Universidad de Oviedo, Avda. Calvo Sotelo 18, E-33007 Oviedo, Asturias (Spain)
2010-03-15T23:59:59.000Z
We perform a study of the gravitating electrostatic spherically symmetric (G-ESS) solutions of Einstein field equations minimally coupled to generalized nonlinear Abelian gauge models in three space dimensions. These models are defined by Lagrangian densities which are general functions of the gauge field invariants, restricted by some physical conditions of admissibility. They include the class of nonlinear electrodynamics supporting electrostatic spherically symmetric (ESS) nontopological soliton solutions in absence of gravity. We establish that the qualitative structure of the G-ESS solutions of admissible models is fully characterized by the asymptotic and central-field behaviors of their ESS solutions in flat space (or, equivalently, by the behavior of the Lagrangian densities in vacuum and on the point of the boundary of their domain of definition, where the second gauge invariant vanishes). The structure of these G-ESS configurations for admissible models supporting divergent-energy ESS solutions in flat space is qualitatively the same as in the Reissner-Nordstroem case. In contrast, the G-ESS configurations of the models supporting finite-energy ESS solutions in flat space exhibit new qualitative features, which are discussed in terms of the Arnowitt-Deser-Misner mass, the charge, and the soliton energy. Most of the results concerning well-known models, such as the electrodynamics of Maxwell, Born-Infeld, and the Euler-Heisenberg effective Lagrangian of QED, minimally coupled to gravitation, are shown to be corollaries of general statements of this analysis.
Mazlish, Bruce
Globalism and globalization have been seen as competitors to other allegiances, namely regionalism and nationalism. A look at recent efforts at reconceptualizing global history in China, Korea and the U.S., however, suggests ...
Hartman, C W; Reisman, D B; McLean, H S; Thomas, J
2007-05-30T23:59:59.000Z
A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.
Giacomelli, L. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Conroy, S. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Gorini, G. [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy)] [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)] [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)
2014-02-15T23:59:59.000Z
The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/? discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.
Electrostatic self-energy in static black holes with spherical symmetry
B. Linet
2000-06-28T23:59:59.000Z
We determine the expression of the electrostatic self-energy for a point charge in the static black holes with spherical symmetry having suitable properties
Application Of A Spherical-Radial Heat Transfer Model To Calculate...
Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...
Cauchy-perturbative matching reexamined: Tests in spherical symmetry
Zink, Burkhard [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Pazos, Enrique [Department of Physics and Astronomy, 202 Nicholson Hall, Louisana State University, Baton Rouge, Louisiana 70803 (United States); Center for Computation and Technology, 302 Johnston Hall, Louisana State University, Baton Rouge, Louisiana 70803 (United States); Departamento de Matematica, Universidad de San Carlos de Guatemala, Edificio T4, Facultad de Ingenieria, Ciudad Universitaria Z. 12 (Guatemala); Diener, Peter; Tiglio, Manuel [Department of Physics and Astronomy, 202 Nicholson Hall, Louisana State University, Baton Rouge, Louisiana 70803 (United States); Center for Computation and Technology, 302 Johnston Hall, Louisana State University, Baton Rouge, Louisiana 70803 (United States)
2006-04-15T23:59:59.000Z
During the last few years progress has been made on several fronts making it possible to revisit Cauchy-perturbative matching (CPM) in numerical relativity in a more robust and accurate way. This paper is the first in a series where we plan to analyze CPM in the light of these new results. One of the new developments is an understanding of how to impose constraint-preserving boundary conditions (CPBC); though most of the related research has been driven by outer boundaries, one can use them for matching interface boundaries as well. Another front is related to numerically stable evolutions using multiple patches, which in the context of CPM allows the matching to be performed on a spherical surface, thus avoiding interpolations between Cartesian and spherical grids. One way of achieving stability for such schemes of arbitrary high order is through the use of penalty techniques and discrete derivatives satisfying summation by parts (SBP). Recently, new, very efficient and high-order accurate derivatives satisfying SBP and associated dissipation operators have been constructed. Here we start by testing all these techniques applied to CPM in a setting that is simple enough to study all the ingredients in great detail: Einstein's equations in spherical symmetry, describing a black hole coupled to a massless scalar field. We show that with the techniques described above, the errors introduced by Cauchy-perturbative matching are very small, and that very long-term and accurate CPM evolutions can be achieved. Our tests include the accretion and ring-down phase of a Schwarzschild black hole with CPM, where we find that the discrete evolution introduces, with a low spatial resolution of {delta}r=M/10, an error of 0.3% after an evolution time of 1,000,000M. For a black hole of solar mass, this corresponds to approximately 5s, and is therefore at the lower end of timescales discussed e.g. in the collapsar model of gamma-ray burst engines.
Fire Safety Tests for Cesium-Loaded Spherical Resorcinol Formaldehyde Resin: Data Summary Report
Kim, Dong-Sang; Schweiger, Michael J.; Peterson, Reid A.
2012-09-01T23:59:59.000Z
A draft safety evaluation of the scenario for spherical resorcinol formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping. To resolve this question, the fire properties of the SRF resin were measured by Southwest Research Institute (SwRI) through a subcontract managed by Pacific Northwest National Laboratory (PNNL). The results of initial fire safety tests on the SRF resin were documented in a previous report (WTP-RPT-218). The present report summarizes the results of additional tests performed by SwRI on the cesium-loaded SRF resin. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. The as-received SwRI report is attached to this report in the Appendix A. Where applicable, the precision and bias of each test method, as given by each American Society for Testing and Materials (ASTM) standard procedure, are included and compared with the SwRI test results of the cesium-loaded SRF resin.
Fire Safety Tests for Spherical Resorcinol Formaldehyde Resin: Data Summary Report
Kim, Dong-Sang; Peterson, Reid A.; Schweiger, Michael J.
2012-07-30T23:59:59.000Z
A draft safety evaluation of the scenario for spherical resorcinol-formaldehyde (SRF) resin fire inside the ion exchange column was performed by the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Fire Safety organization. The result of this draft evaluation suggested a potential change of the fire safety classification for the Cesium Ion Exchange Process System (CXP) emergency elution vessels, equipment, and piping, which may be overly bounding based on the fire performance data from the manufacturer of the ion exchange resin selected for use at the WTP. To resolve this question, the fire properties of the SRF resin were measured by Southwest Research Institute (SwRI), following the American Society for Testing and Materials (ASTM) standard procedures, through a subcontract managed by Pacific Northwest National Laboratory (PNNL). For some tests, the ASTM standard procedures were not entirely appropriate or practical for the SRF resin material, so the procedures were modified and deviations from the ASTM standard procedures were noted. This report summarizes the results of fire safety tests performed and reported by SwRI. The efforts by PNNL were limited to summarizing the test results provided by SwRI into one consolidated data report. All as-received SwRI reports are attached to this report in the Appendix. Where applicable, the precision and bias of each test method, as given by each ASTM standard procedure, are included and compared with the SwRI test results of the SRF resin.
Structures of Spherical Viral Capsids as Quasicrystalline Tilings
O. V. Konevtsova; V. L. Lorman; S. B. Rochal
2015-01-16T23:59:59.000Z
Spherical viral shells with icosahedral symmetry are considered as quasicrystalline tilings. Similarly to known Caspar-Klug quasi-equivalence theory, the presented approach also minimizes the number of conformations necessary for the protein molecule bonding with its neighbors in the shell, but is based on different geometrical principles. It is assumed that protein molecule centers are located at vertices of tiles with identical edges, and the number of different tile types is minimal. Idealized coordinates of nonequivalent by symmetry protein positions in six various capsid types are obtained. The approach describes in a uniform way both the structures satisfying the well-known Caspar and Klug geometrical model and the structures contradicting this model.
Brane solutions of a spherical sigma model in six dimensions
Hyun Min Lee; Antonios Papazoglou
2004-11-16T23:59:59.000Z
We explore solutions of six dimensional gravity coupled to a non-linear sigma model, in the presence of co-dimension two branes. We investigate the compactifications induced by a spherical scalar manifold and analyze the conditions under which they are of finite volume and singularity free. We discuss the issue of single-valuedness of the scalar fields and provide some special embedding of the scalar manifold to the internal space which solves this problem. These brane solutions furnish some self-tuning features, however they do not provide a satisfactory explanation of the vanishing of the effective four dimensional cosmological constant. We discuss the properties of this model in relation with the self-tuning example based on a hyperbolic sigma model.
Plasma Viscosity with Mass Transport in Spherical ICF Implosion Simulations
Vold, Erik L; Ortega, Mario I; Moll, Ryan; Fenn, Daniel; Molvig, Kim
2015-01-01T23:59:59.000Z
The effects of viscosity and small-scale atomic-level mixing on plasmas in inertial confinement fusion (ICF) currently represent challenges in ICF research. Many current ICF hydrodynamic codes ignore the effects of viscosity though recent research indicates viscosity and mixing by classical transport processes may have a substantial impact on implosion dynamics. We have implemented a Lagrange hydrodynamic code in one-dimensional spherical geometry with plasma viscosity and mass transport and including a three temperature model for ions, electrons, and radiation treated in a gray radiation diffusion approximation. The code is used to study ICF implosion differences with and without plasma viscosity and to determine the impacts of viscosity on temperature histories and neutron yield. It was found that plasma viscosity has substantial impacts on ICF shock dynamics characterized by shock burn timing, maximum burn temperatures, convergence ratio, and time history of neutron production rates. Plasma viscosity reduc...
Reactive self-heating model of aluminum spherical nanoparticles
Karen S. Martirosyan; Maxim Zyskin
2012-12-17T23:59:59.000Z
Aluminum-oxygen reaction is important in many highly energetic, high pressure generating systems. Recent experiments with nanostructured thermites suggest that oxidation of aluminum nanoparticles occurs in a few microseconds. Such rapid reaction cannot be explained by a conventional diffusion-based mechanism. We present a rapid oxidation model of a spherical aluminum nanoparticle, using Cabrera-Mott moving boundary mechanism, and taking self-heating into account. In our model, electric potential solves the nonlinear Poisson equation. In contrast with the Coulomb potential, a "double-layer" type solution for the potential and self-heating leads to enhanced oxidation rates. At maximal reaction temperature of 2000 C, our model predicts overall oxidation time scale in microseconds range, in agreement with experimental evidence.
Spherically symmetric cosmological spacetimes with dust and radiation — numerical implementation
Lim, Woei Chet [Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton 3240 (New Zealand); Regis, Marco [Dipartimento di Fisica, Università di Torino and INFN, Torino (Italy); Clarkson, Chris, E-mail: wclim@waikato.ac.nz, E-mail: regis@to.infn.it, E-mail: chris.clarkson@gmail.com [Astrophysics, Cosmology and Gravity Centre, and Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)
2013-10-01T23:59:59.000Z
We present new numerical cosmological solutions of the Einstein Field Equations. The spacetime is spherically symmetric with a source of dust and radiation approximated as a perfect fluid. The dust and radiation are necessarily non-comoving due to the inhomogeneity of the spacetime. Such a model can be used to investigate non-linear general relativistic effects present during decoupling or big-bang nucleosynthesis, as well as for investigating void models of dark energy with isocurvature degrees of freedom. We describe the full evolution of the spacetime as well as the redshift and luminosity distance for a central observer. After demonstrating accuracy of the code, we consider a few example models, and demonstrate the sensitivity of the late time model to the degree of inhomogeneity of the initial radiation contrast.
Reactive self-heating model of aluminum spherical nanoparticles
Martirosyan, Karen S
2012-01-01T23:59:59.000Z
Aluminum-oxygen reaction is important in many highly energetic, high pressure generating systems. Recent experiments with nanostructured thermites suggest that oxidation of aluminum nanoparticles occurs in a few microseconds. Such rapid reaction cannot be explained by a conventional diffusion-based mechanism. We present a rapid oxidation model of a spherical aluminum nanoparticle, using Cabrera-Mott moving boundary mechanism, and taking self-heating into account. In our model, electric potential solves the nonlinear Poisson equation. In contrast with the Coulomb potential, a "double-layer" type solution for the potential and self-heating leads to enhanced oxidation rates. At maximal reaction temperature of 2000 C, our model predicts overall oxidation time scale in microseconds range, in agreement with experimental evidence.
Self Tuning Scalar Fields in Spherically Symmetric Spacetimes
Appleby, Stephen
2015-01-01T23:59:59.000Z
We search for self tuning solutions to the Einstein-scalar field equations for the simplest class of `Fab-Four' models with constant potentials. We first review the conditions under which self tuning occurs in a cosmological spacetime, and by introducing a small modification to the original theory - introducing the second and third Galileon terms - show how one can obtain de Sitter states where the expansion rate is independent of the vacuum energy. We then consider whether the same self tuning mechanism can persist in a spherically symmetric inhomogeneous spacetime. We show that there are no asymptotically flat solutions to the field equations in which the vacuum energy is screened, other than the trivial one (Minkowski space). We then consider the possibility of constructing Schwarzschild de Sitter spacetimes for the modified Fab Four plus Galileon theory. We argue that the only model that can successfully screen the vacuum energy in both an FLRW and Schwarzschild de Sitter spacetime is one containing `John...
A simple procedure to prepare spherical {alpha}-alumina powders
Liu Hongyu [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China); Ning Guiling [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China)], E-mail: ninggl@dlut.edu.cn; Gan Zhihong; Lin Yuan [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China)
2009-04-02T23:59:59.000Z
Spherical {alpha}-alumina powders were prepared by the controlled hydrolysis of aluminum isopropoxide in a hydrolysis system consisting of octanol and acetonitrile. Diverse solvents to dissolve reactant formed diverse hydrolysis systems and affected particle shape of {alpha}-alumina powders. The precursors crystallized to {gamma}-alumina at 1000 deg. C and converted to {alpha}-alumina at 1150 deg. C without intermediate phases. The particle morphology of precursor was retained after it crystallized to {alpha}-alumina. The heating rate influenced the particle shape and the state of agglomeration during calcination process. The thermal properties of the precursors were characterized by thermal gravimetric and differential thermal analysis. X-ray diffraction technique was used to confirm the conversion of crystalline phase of alumina powders from amorphous to {alpha}-phase. Transmission electron microscopy was used to investigate the morphologies and size of the precursors and products.
Distorted black holes from a vacuum 5-d spherical solution
Capistrano, Abraão J S; Ulhoa, Sergio C; Amorim, Ronni G G
2015-01-01T23:59:59.000Z
We study the deformation caused by the influence of extrinsic curvature on a vacuum spherically symmetric metric embedded in a 5-d bulk. In this sense, we investigate the produced stationary black-holes and derive general properties such as its mass and horizons. As an application, a test moving particle near such black-holes is also shown as well the distortion caused by extrinsic curvature on its movement. Accordingly, using asymptotically conformal flat condition on the extrinsic curvature and an analytical expansion of a set of \\emph{n}-scalar fields, we show that the resulting black holes must be large and constrained in the range $-1/2 \\leq n \\leq 1.8$ that are locally thermodynamically stable, but not globally preferred.
Frequency Dependent Specific Heat from Thermal Effusion in Spherical Geometry
Bo Jakobsen; Niels Boye Olsen; Tage Christensen
2010-03-11T23:59:59.000Z
We present a novel method of measuring the frequency dependent specific heat at the glass transition applied to 5-polyphenyl-4-ether. The method employs thermal waves effusing radially out from the surface of a spherical thermistor that acts as both a heat generator and thermometer. It is a merit of the method compared to planar effusion methods that the influence of the mechanical boundary conditions are analytically known. This implies that it is the longitudinal rather than the isobaric specific heat that is measured. As another merit the thermal conductivity and specific heat can be found independently. The method has highest sensitivity at a frequency where the thermal diffusion length is comparable to the radius of the heat generator. This limits in practise the frequency range to 2-3 decades. An account of the 3omega-technique used including higher order terms in the temperature dependency of the thermistor and in the power generated is furthermore given.
Anisotropic diffusion of spherical particles in closely confining microchannels
Dettmer, Simon L; Misiunas, Karolis; Keyser, Ulrich F
2014-01-01T23:59:59.000Z
We present here the measurement of the diffusivity of spherical particles closely confined by narrow microchannels. Our experiments yield a 2D map of the position-dependent diffusion coefficients parallel and perpendicular to the channel axis with a resolution down to 129 nm. The diffusivity was measured simultaneously in the channel interior, the bulk reservoirs as well as the channel entrance region. In the channel interior we found strongly anisotropic diffusion. While the perpendicular diffusion coefficient close to the confining walls decreased down to approximately 25 % of the value on the channel axis, the parallel diffusion coefficient remained constant throughout the entire channel width. In addition to the experiment, we performed finite element simulations for the diffusivity in the channel interior and found good agreement with the measurements. Our results reveal the distinctive influence of strong confinement on Brownian motion which is of significance to microfluidics as well as quantitative mo...
Exit time distribution in spherically symmetric two-dimensional domains
Rupprecht, J -F; Grebenkov, D S; Voituriez, R
2014-01-01T23:59:59.000Z
The distribution of exit times is computed for a Brownian particle in spherically symmetric two- dimensional domains (disks, angular sectors, annuli) and in rectangles that contain an exit on their boundary. The governing partial differential equation of Helmholtz type with mixed Dirichlet- Neumann boundary conditions is solved analytically. We propose both an exact solution relying on a matrix inversion, and an approximate explicit solution. The approximate solution is shown to be exact for an exit of vanishing size and to be accurate even for large exits. For angular sectors, we also derive exact explicit formulas for the moments of the exit time. For annuli and rectangles, the approximate expression of the mean exit time is shown to be very accurate even for large exits. The analysis is also extended to biased diffusion. Since the Helmholtz equation with mixed boundary conditions is encountered in microfluidics, heat propagation, quantum billiards, and acoustics, the developed method can find numerous appl...
Pantex receives National Weather Service recognition | National...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
receives National Weather Service recognition | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...
National Nuclear Security Administration | National Nuclear Security...
National Nuclear Security Administration (NNSA)
Us Our Operations Management and Budget Office of Civil Rights Workforce Statistics National Nuclear Security Administration National Nuclear Security Administration...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 Annual Report ErnestNationalNational Lab
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 Annual Report ErnestNationalNational Labdraws more
On the Computation of the Direct Kinematics of Parallel Spherical Mechanisms Using
On the Computation of the Direct Kinematics of Parallel Spherical Mechanisms Using Bernstein Solving the direct kinematics of parallel spherical mechanisms with l legs boils down to solving systems the direct kinematics of these mechanisms that takes ad- vantage of the subdivision and convex hull
Diffusion within a Layered, Graphite-Like, Spherical Electrode Theoretical Aspects
Taylor, Philip L.
Diffusion within a Layered, Graphite-Like, Spherical Electrode Theoretical Aspects Paul B. Antohi. Within this model, which mimics a layered, graphite-like spherical electrode, species can enter or leave further performance optimization of Li+ batteries have generated renewed interest into experimental
Study of plasma heating in ohmically and auxiliary heated regimes in spherical tokamak Globus-M.
Boyer, Edmond
Study of plasma heating in ohmically and auxiliary heated regimes in spherical tokamak Globus-M. N, Russia INTRODUCTION This paper describes the basic features of the plasma heating in spherical tokamak direction in the tokamak midplane. The beam axis was aimed into the inner plasma region at the radius R = 0
A Multipole Based Treecode Using Spherical Harmonics for Potentials of the Form r-
Sarin, Vivek
A Multipole Based Treecode Using Spherical Harmonics for Potentials of the Form r- Kasthuri spherical harmonics to compute multipole coefficients that are used to evaluate these potentials. The key of the multipole expansion theorem used in the classical fast multipole algorithm [2]. This theorem is used
The Dual Horospherical Radon Transform as a Limit of Spherical Radon Transforms
Pasquale, Angela
The Dual Horospherical Radon Transform as a Limit of Spherical Radon Transforms J. Hilgert, A of G. The horospherical Radon transform maps functions on X to functions on HorX by integrating over the dual horospherical Radon transform as a limit of dual spherical Radon transforms. 1. Introduction
The dynamic response of edge clamped plates loaded by spherically expanding sand shellsq
Wadley, Haydn
The dynamic response of edge clamped plates loaded by spherically expanding sand shellsq Kumar P and water saturated sand has been investigated, both experimentally and via a particle based simulation methodology. The spherically expanding sand shell is generated by detonating a sphere of explosive surrounded
McEwen, Jason
spherical wavelet transform algorithms J. D. McEwen, M. P. Hobson, D. J. Mortlock, A. N. Lasenby Abstract-- We describe the construction of a spherical wavelet analysis through the inverse stereographic projection of the Euclidean planar wavelet framework, introduced originally by Antoine and Vandergheynst
An exact solution for the Casimir force in a spherically symmetric medium
Ulf Leonhardt; William M. R. Simpson
2011-07-03T23:59:59.000Z
We calculated the force of the quantum vacuum, the Casimir force, in a spherically symmetric medium, Maxwell's fish eye, surrounded by a perfect mirror and derived an exact analytic solution. Our solution questions the idea that the Casimir force of a spherical mirror is repulsive - we found an attractive force that diverges at the mirror.
Thermoelectric detection of spherical tin inclusions in copper by magnetic sensing
Nagy, Peter B.
Thermoelectric detection of spherical tin inclusions in copper by magnetic sensing Hector Carreon by noncontacting magnetic measurements that sense the thermoelectric currents around such flaws when the specimen produced by thermoelectric currents around surface-breaking spherical tin inclusions in copper under
Processes for making dense, spherical active materials for lithium-ion cells
Kang, Sun-Ho (Naperville, IL); Amine, Khalil (Downers Grove, IL)
2011-11-22T23:59:59.000Z
Processes are provided for making dense, spherical mixed-metal carbonate or phosphate precursors that are particularly well suited for the production of active materials for electrochemical devices such as lithium ion secondary batteries. Exemplified methods include precipitating dense, spherical particles of metal carbonates or metal phosphates from a combined aqueous solution using a precipitating agent such as ammonium hydrogen carbonate, sodium hydrogen carbonate, or a mixture that includes sodium hydrogen carbonate. Other exemplified methods include precipitating dense, spherical particles of metal phosphates using a precipitating agent such as ammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, or a mixture of any two or more thereof. Further provided are compositions of and methods of making dense, spherical metal oxides and metal phosphates using the dense, spherical metal precursors. Still further provided are electrodes and batteries using the same.
Zhang Yang [Institute of Applied Physics and Computational Mathematics, P. O. Box 8009-09, Beijing 100094 (China); Institute of Nuclear Physics and Chemistry, P. O. Box 919-212, Mianyang 621900 (China); Ding Ning; Sun Shunkai; Xue Chuang; Ning Cheng; Xiao Delong; Huang Jun [Institute of Applied Physics and Computational Mathematics, P. O. Box 8009-09, Beijing 100094 (China); Li Zhenghong [Institute of Nuclear Physics and Chemistry, P. O. Box 919-212, Mianyang 621900 (China)
2012-12-15T23:59:59.000Z
Implosions of (quasi-)spherical loads with mass redistribution and displacement modification are investigated numerically. Both methods can theoretically counterbalance the nonuniformity of magnetic pressure along the load surface and realize quasi-spherical Z-pinch implosions. Mass redistribution is feasible for spherical loads with large radius and weight, while the displacement modification is more suitable for light loads, such as those composed of wire arrays. Simulation results suggest that, for mass redistributed spherical loads, wall instabilities induced by polar mass flows will deform the imploding shell. For prolate spherical loads, in which the wall instability cannot develop, the kinetic energy distribution is disturbed at high latitude. These passive behaviors and their possible mitigation methods, such as reshaping the electrode, are investigated numerically in this paper.
Analysis of spherically symmetric black holes in Braneworld models
A. B. Pavan
2010-05-25T23:59:59.000Z
Research on black holes and their physical proprieties has been active on last 90 years. With the appearance of the String Theory and the Braneworld models as alternative descriptions of our Universe, the interest on black holes, in these context, increased. In this work we studied black holes in Braneworld models. A class of spherically symmetric black holes is investigaded as well its stability under general perturbations. Thermodynamic proprieties and quasi-normal modes are discussed. The black holes studied are the SM (zero mass) and CFM solutions, obtained by Casadio {\\it et al.} and Bronnikov {\\it et al.}. The geometry of bulk is unknown. However the Campbell-Magaard Theorem guarantees the existence of a 5-dimensional solution in the bulk whose projection on the brane is the class of black holes considered. They are stable under scalar perturbations. Quasi-normal modes were observed in both models. The tail behavior of the perturbations is the same. The entropy upper bound of a body absorved by the black holes studied was calculated. This limit turned out to be independent of the black hole parameters.
Octahedral spherical hohlraum and its laser arrangement for inertial fusion
Lan, Ke; He, Xian-Tu; Liu, Jie [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zheng, Wudi; Lai, Dongxian [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
2014-05-15T23:59:59.000Z
A recent publication [K. Lan et al., Phys. Plasmas 21, 010704 (2014)] proposed a spherical hohlraum with six laser entrance holes of octahedral symmetry at a specific hohlraum-to-capsule radius ratio of 5.14 for inertial fusion study, which has robust high symmetry during the capsule implosion and superiority on low backscatter without supplementary technology. This paper extends the previous one by studying the laser arrangement and constraints of octahedral hohlraum in detail. As a result, it has serious beam crossing at ?{sub L}?45°, and ?{sub L}=50° to 60° is proposed as the optimum candidate range for the golden octahedral hohlraum, here ?{sub L} is the opening angle that the laser quad beam makes with the Laser Entrance Hole (LEH) normal direction. In addition, the design of the LEH azimuthal angle should avoid laser spot overlapping on hohlraum wall and laser beam transferring outside hohlraum from a neighbor LEH. The octahedral hohlraums are flexible and can be applicable to diverse inertial fusion drive approaches. This paper also applies the octahedral hohlraum to the recent proposed hybrid indirect-direct drive approach.
Complete fusion of $^9$Be with spherical targets
Henning Esbensen
2010-03-02T23:59:59.000Z
The complete fusion of $^9$Be with $^{144}$Sm and $^{208}$Pb targets is calculated in the coupled-channels approach. The calculations include couplings between the 3/2$^-$, 5/2$^-$, and 7/2$^-$ states in the $K=3/2$ ground state rotational band of $^9$Be. It is shown that the $B(E2)$ values for the excitation of these states are accurately described in the rotor model. The interaction of the strongly deformed $^9$Be nucleus with a spherical target is calculated using the double-folding technique and the effective M3Y interaction, which is supplemented with a repulsive term that is adjusted to optimize the fit to the data for the $^{144}$Sm target. The complete fusion is described by in-going-wave boundary conditions. The decay of the unbound excited states in $^9$Be is considered explicitly in the calculations by using complex excitation energies. The model gives an excellent account of the complete fusion (CF) data for $^9$Be+$^{144}$Sm, and the cross sections for the decay of the excited states are in surprisingly good agreement with the incomplete fusion (ICF) data. Similar calculations for $^9$Be+$^{208}$Pb explain the total fusion data at high energies but fail to explain the CF data, which are suppressed by 20%, and the calculated cross section for the decay of excited states is a factor of three smaller than the ICF data at high energies. Possible reasons for these discrepancies are discussed.
A Keplerian Limit to Static Spherical Spacetimes in Curvature Coordinates
Tyler J. Lemmon; Antonio R. Mondragon
2008-09-04T23:59:59.000Z
The problem of a test body in the Schwarzschild geometry is investigated in a Keplerian limit. Beginning with the Schwarzschild metric, a solution to the limited case of approximately elliptical (Keplerian) motion is derived in terms of trigonometric functions. This solution is similar in form to that derived from Newtonian mechanics, and includes first-order corrections describing three effects due to general relativity: precession; reduced radial coordinate; and increased eccentricity. The quantitative prediction of increased eccentricity may provide an additional observational test of general relativity. By analogy with Keplerian orbits, approximate orbital energy parameters are defined in terms of a relativistic eccentricity, providing first-order corrections to Newtonian energies for elliptical orbits. The first-order relativistic equation of orbit is demonstrated to be a limiting case of a very accurate self-consistent solution. This self-consistent solution is supported by exact numerical solutions to the Schwarzschild geometry, displaying remarkable agreement. A more detailed energy parameterization is investigated using the relativistic eccentricity together with the apsides derived from the relativistic effective potential in support of the approximate energy parameters defined using only first-order corrections. The methods and approximations describing this Keplerian limit are applied to more general static spherically-symmetric geometries. Specifically, equations of orbit and energy parameters are also derived in this Keplerian limit for the Reissner-Nordstr\\"{o}m and Schwarzschild-de Sitter metrics.
Relaxation in N-body simulations of spherical systems
Sellwood, J A
2015-01-01T23:59:59.000Z
I present empirical measurements of the rate of relaxation in N-body simulations of stable spherical systems and distinguish two separate causes of relaxation: two-body effects, which cause energy exchange between particles of differing masses, and collective oscillations driven by shot noise that lead to an enhanced energy diffusion rate. I use four different methods to compute the gravitational field, and a 100-fold range in the numbers of particles in each case. I find the rate at which energy is exchanged between particles of differing masses does not depend at all on the force determination method, but I do find the energy diffusion rate, which is substantially enhanced by collective modes, is marginally lower when a field method is used. The relaxation rate in 3D is virtually independent of the method used because it is dominated by distant encounters; any method to estimate the gravitational field that correctly captures the contributions from distant particles must also capture their statistical fluct...
Ramp-up of CHI Initiated Plasmas on NSTX
Mueller, D; Bell, R E; LeBlanc, B; Roquemore, A L; Raman, R; Jarboe, T R; Nelson, B A
2009-10-29T23:59:59.000Z
Experiments on the National Spherical Torus (NSTX) have now demonstrated flux savings using transient coaxial helicity injection (CHI). In these discharges, the discharges initiated by CHI are ramped up with an inductive transformer and exhibit higher plasma current than discharges without the benefit of CHI initiation.
NSTX Weekly Report (Mar. 5, 2010) FY 2010 NSTX plasma operations
Princeton Plasma Physics Laboratory
`Demonstration of Tokamak Ohmic Flux Saving by Transient Coaxial Helicity Injection on NSTX' by R. Raman et al and in future toroidal devices. (R. Raman, University of Washington) The paper "Advances in high-harmonic fast wave physics in the National Spherical Torus Experiment" by G. Taylor, et al. has been accepted
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073
Ion Loss in the National Spherical Torus Experiment by E.D. Fredrickson, C.Z. Cheng, D. Darrow, G. Fu Experiment E.D. Fredrickson, C.Z. Cheng, D. Darrow, G. Fu, N.N. Gorelenkov, G Kramer, S S Medley, J. Menard
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073
.D. Fredrickson, N. Gorelenkov, C.Z. Cheng, R. Bell, D. Darrow, D. Johnson, S. Kaye, B. LeBlanc, J. Menard, S on the National Spherical Torus Experiment E.D. Fredrickson, N. Gorelenkov, C.Z. Cheng, R. Bell, D. Darrow, D
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073
.D. Fredrickson, N. Gorelenkov, C.Z. Cheng, R. Bell, D. Darrow, D. Johnson, S. Kaye, B. LeBlanc, J. Menard, S Beam Heating on the National Spherical Torus Experiment E.D. Fredrickson, N. Gorelenkov, C.Z. Cheng, R
Paul Sichta 8th International Conference on Accelerator
Princeton Plasma Physics Laboratory
Extension Energy Development EnergyFuture Present Advance in Fusion Energy Technology Advancein;National Spherical Torus eXperiment · Fusion Energy Research· Fusion Energy Research ·· The NSTX Facility&VMS AnalysisX-Windows&local Apps VMS MDSplus Solaris EPICS VME EPICS IOC PLC VME FPDP MDSplus Database CAMAC RS
Energy-momentum Prescriptions in General Spherically Symmetric Space-times
Saeed Mirshekari; Amir M. Abbassi
2014-11-29T23:59:59.000Z
Einstein, Landau-Lifshitz, Papapetrou, Weinberg, and M{\\o}ller energy-momentum prescriptions in general spherically symmetric space-times are investigated. It is shown that for two special but not unusual classes of general spherically symmetric space-times several energy-momentum prescriptions in Schwarzschild Cartesian coordinates lead to some coincidences in energy distribution. It is also obtained that for a special class of spherically symmetric metrics M{\\o}ller and Einstein energy-momentum prescriptions give the same result for energy distribution if and only if it has a specific dependence on radial coordinate.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) | SciTech Connect Journal Article: X-rayContract DocumentsofDioxide CaptureAssistance ProgramNationalSecurity LLNL's
National System Templates: Building Sustainable National Inventory...
System Templates: Building Sustainable National Inventory Management Systems Jump to: navigation, search Tool Summary LAUNCH TOOL Name: National System Templates: Building...
NATIONAL SECURITY TECHNOLOGIES - NEVADA NATIONAL SECURITY SITE
National Nuclear Security Administration (NNSA)
NATIONAL SECURITY TECHNOLOGIES - NEVADA NATIONAL SECURITY SITE FISCAL YEARS 2009 THRU 2015 SMALL BUSINESS PROGRAM RESULTS & FORECAST CATEGORY Total Procurement Total SB Small...
A classification of spherically symmetric self-similar dust models
B. J. Carr
2000-03-02T23:59:59.000Z
We classify all spherically symmetric dust solutions of Einstein's equations which are self-similar in the sense that all dimensionless variables depend only upon $z\\equiv r/t$. We show that the equations can be reduced to a special case of the general perfect fluid models with equation of state $p=\\alpha \\mu$. The most general dust solution can be written down explicitly and is described by two parameters. The first one (E) corresponds to the asymptotic energy at large $|z|$, while the second one (D) specifies the value of z at the singularity which characterizes such models. The E=D=0 solution is just the flat Friedmann model. The 1-parameter family of solutions with z>0 and D=0 are inhomogeneous cosmological models which expand from a Big Bang singularity at t=0 and are asymptotically Friedmann at large z; models with E>0 are everywhere underdense relative to Friedmann and expand forever, while those with E0 ones. The 2-parameter solutions with D>0 again represent inhomogeneous cosmological models but the Big Bang singularity is at $z=-1/D$, the Big Crunch singularity is at $z=+1/D$, and any particular solution necessarily spans both z0. While there is no static model in the dust case, all these solutions are asymptotically ``quasi-static'' at large $|z|$. As in the D=0 case, the ones with $E \\ge 0$ expand or contract monotonically but the latter may now contain a naked singularity. The ones with E<0 expand from or recollapse to a second singularity, the latter containing a black hole.
Response of grooved composites to transversely distributed and localized spherical contact loadings
Jeffrey, Holly K
2011-01-01T23:59:59.000Z
The response of a grooved composite specimen to two contact loading situations is studied; load applied via a transversely oriented cylindrical indenter and via a localized spherical ball-ended indenter. The philosophy of ...
Design of a spherical vehicle with flywheel momentum storage for high torque capabilities
Schroll, Gregory C. (Gregory Cordner)
2008-01-01T23:59:59.000Z
A novel method for supplementing the propulsion of a spherical ground vehicle was conceived and developed. The addition of angular momentum storage via counter-rotating control moment gyroscopes is proposed in order to ...
A two-phase spherical electric machine for generating rotating uniform magnetic fields
Lawler, Clinton T. (Clinton Thomas)
2007-01-01T23:59:59.000Z
This thesis describes the design and construction of a novel two-phase spherical electric machine that generates rotating uniform magnetic fields, known as a fluxball machine. Alternative methods for producing uniform ...
True Polar Wander: linking Deep and Shallow Geodynamics to Hydro-and Bio-Spheric Hypotheses
True Polar Wander: linking Deep and Shallow Geodynamics to Hydro- and Bio-Spheric Hypotheses T. D on the bulk solid Earth over longer tirnescales 565 #12;566 Linking Deep and Shallow Geodynamics to Hydro
Gravitational radiation, energy and reaction on quasi-spherical black holes
Sean A. Hayward
2001-02-05T23:59:59.000Z
Gravitational radiation is locally defined where the wavefronts are roughly spherical. A local energy tensor is defined for the gravitational radiation. Including this energy tensor as a source in the truncated Einstein equations describes gravitational radiation reaction, such as back-reaction on a roughly spherical black hole. The energy-momentum in a canonical frame is covariantly conserved. The strain to be measured by a distant detector is simply defined.
Harris, Matthew Wade
2007-09-17T23:59:59.000Z
A NEW ANALYTICAL MODEL FOR STRESS CONCENTRATION AROUND HARD SPHERICAL PARTICLES IN METAL MATRIX COMPOSITES A Senior Scholars Thesis by MATTHEW WADE HARRIS Submitted to the Office of Undergraduate Research Texas... AROUND HARD SPHERICAL PARTICLES IN METAL MATRIX COMPOSITES A Senior Scholars Thesis by MATTHEW WADE HARRIS Submitted to the Office of Undergraduate Research Texas A&M University in partial fulfillment of the requirements...
Newtonian wormholes with spherical symmetry and tidal forces on test particles
Paulo Luz; José P. S. Lemos
2015-05-23T23:59:59.000Z
A spherically symmetric wormhole in Newtonian gravitation in curved space, enhanced with a connection between the mass density and the Ricci scalar, is presented. The wormhole, consisting of two connected asymptotically flat regions, inhabits a spherically symmetric curved space. The gravitational potential, gravitational field and the pressure that supports the fluid that permeates the Newtonian wormhole are computed. Particle dynamics and tidal effects in this geometry are studied. The possibility of having Newtonian black holes in this theory is sketched.
Geometric Design of Spherical Serial Chains with Curvature Constraints in the Environment
Tolety, Anurag Bharadwaj
2012-10-19T23:59:59.000Z
2011 Major Subject: Electrical Engineering GEOMETRIC DESIGN OF SPHERICAL SERIAL CHAINS WITH CURVATURE CONSTRAINTS IN THE ENVIRONMENT A Thesis by ANURAG BHARADWAJ TOLETY Submitted to the O ce of Graduate Studies of Texas A&M University in partial... Georghiades August 2011 Major Subject: Electrical Engineering iii ABSTRACT Geometric Design of Spherical Serial Chains with Curvature Constraints in the Environment. (August 2011) Anurag Bharadwaj Tolety, B. Tech., Indian Institute of Technology...
National Security Initiatives | ORNL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Cyber Security Nuclear Forensics Bioinformatics Facilities Events and Conferences Supporting Organizations National Security Home | Science & Discovery | National Security |...
Investigation of Gas Solid Fluidized Bed Dynamics with Non-Spherical Particles
Choudhuri, Ahsan
2013-06-30T23:59:59.000Z
One of the largest challenges for 21st century is to fulfill global energy demand while also reducing detrimental impacts of energy generation and use on the environment. Gasification is a promising technology to meet the requirement of reduced emissions without compromising performance. Coal gasification is not an incinerating process; rather than burning coal completely a partial combustion takes place in the presence of steam and limited amounts of oxygen. In this controlled environment, a chemical reaction takes place to produce a mixture of clean synthetic gas. Gas-solid fluidized bed is one such type of gasification technology. During gasification, the mixing behavior of solid (coal) and gas and their flow patterns can be very complicated to understand. Many attempts have taken place in laboratory scale to understand bed hydrodynamics with spherical particles though in actual applications with coal, the particles are non-spherical. This issue drove the documented attempt presented here to investigate fluidized bed behavior using different ranges of non-spherical particles, as well as spherical. For this investigation, various parameters are controlled that included particle size, bed height, bed diameter and particle shape. Particles ranged from 355 µm to 1180 µm, bed diameter varied from 2 cm to 7 cm, two fluidized beds with diameters of 3.4 cm and 12.4 cm, for the spherical and non-spherical shaped particles that were taken into consideration. Pressure drop was measured with increasing superficial gas velocity. The velocity required in order to start to fluidize the particle is called the minimum fluidization velocity, which is one of the most important parameters to design and optimize within a gas-solid fluidized bed. This minimum fluidization velocity was monitored during investigation while observing variables factors and their effect on this velocity. From our investigation, it has been found that minimum fluidization velocity is independent of bed height for both spherical and non-spherical particles. Further, it decrease with decreasing particle size and decreases with decreasing bed diameter. Shadow sizing, a non-intrusive imaging and diagnostic technology, was also used to visualize flow fields inside fluidized beds for both spherical and non- spherical particles and to detect the particle sizes.
Schrijver, Karel
United Nations Programme on Space Applications UNITED NATIONS UNITED NATIONS OFFICE FOR OUTER SPACE, Sputnik 1. Soon after that event, the Member States of the United Nations declared that space should and natural resources management. At the first United Nations Conference on the Exploration and Peaceful Uses
Non-astigmatic imaging with matched pairs of spherically bent reflectors
Bitter, Manfred Ludwig (Princeton, NJ); Hill, Kenneth Wayne (Plainsboro, NJ); Scott, Steven Douglas (Wellesley, MA); Feder, Russell (Newton, PA); Ko, Jinseok (Cambridge, MA); Rice, John E. (N. Billerica, MA); Ince-Cushman, Alexander Charles (New York, NY); Jones, Frank (Manalapan, NJ)
2012-07-10T23:59:59.000Z
Arrangements for the point-to-point imaging of a broad spectrum of electromagnetic radiation and ultrasound at large angles of incidence employ matched pairs of spherically bent reflectors to eliminate astigmatic imaging errors. Matched pairs of spherically bent crystals or spherically bent multi-layers are used for X-rays and EUV radiation; and matched pairs of spherically bent mirrors that are appropriate for the type of radiation are used with microwaves, infrared and visible light, or ultrasound. The arrangements encompass the two cases, where the Bragg angle--the complement to the angle of incidence in optics--is between 45.degree. and 90.degree. on both crystals/mirrors or between 0.degree. and 45.degree. on the first crystal/mirror and between 45.degree. and 90.degree. on the second crystal/mirror, where the angles of convergence and divergence are equal. For x-rays and EUV radiation, also the Bragg condition is satisfied on both spherically bent crystals/multi-layers.
Density- and wavefunction-normalized Cartesian spherical harmonics for l ? 20
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, J. Robert; Volkov, Anatoliy
2015-03-01T23:59:59.000Z
The widely used pseudoatom formalism in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the density-normalized Cartesian spherical harmonic functions for up to l ? 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens. It was shown that the analytical form for normalization coefficients is available primarily forl ? 4. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 l ? 7.more »In most cases for l > 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens method in the Wolfram Mathematicasoftware to derive the Cartesian spherical harmonics for l ? 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.« less
Modeling Ion-Exchange Processing With Spherical Resins For Cesium Removal
Hang, T.; Nash, C. A.; Aleman, S. E.
2012-09-19T23:59:59.000Z
The spherical Resorcinol-Formaldehyde and hypothetical spherical SuperLig(r) 644 ion-exchange resins are evaluated for cesium removal from radioactive waste solutions. Modeling results show that spherical SuperLig(r) 644 reduces column cycling by 50% for high-potassium solutions. Spherical Resorcinol Formaldehyde performs equally well for the lowest-potassium wastes. Less cycling reduces nitric acid usage during resin elution and sodium addition during resin regeneration, therefore, significantly decreasing life-cycle operational costs. A model assessment of the mechanism behind ''cesium bleed'' is also conducted. When a resin bed is eluted, a relatively small amount of cesium remains within resin particles. Cesium can bleed into otherwise decontaminated product in the next loading cycle. The bleed mechanism is shown to be fully isotherm-controlled vs. mass transfer controlled. Knowledge of residual post-elution cesium level and resin isotherm can be utilized to predict rate of cesium bleed in a mostly non-loaded column. Overall, this work demonstrates the versatility of the ion-exchange modeling to study the effects of resin characteristics on processing cycles, rates, and cold chemical consumption. This evaluation justifies further development of a spherical form of the SL644 resin.
Oak Ridge National Laboratory National Security Programs
Security Challenges #12;3 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY How Will Our Enemies and Homeland Security #12;OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Nuclear Nonproliferation $27,050 Cleanup $7,481 Science $359M National Security $278M Energy $170M Cleanup $0.8M Total $1.08B
National Environmental Information Infrastructure
Greenslade, Diana
National Environmental Information Infrastructure: Reference Architecture Contributing to the Australian Government National Plan for Environmental Information initiative #12;National Environmental Information Infrastructure: Reference Architecture v1.1 Environmental Information Programme Publication Series
Truthing the stretch: Non-perturbative cosmological realizations with multiscale spherical collapse
Neyrinck, Mark C
2015-01-01T23:59:59.000Z
Here we present a simple, parameter-free, non-perturbative algorithm that gives low-redshift cosmological particle realizations accurate to few-Megaparsec scales, called muscle (MUltiscale Spherical ColLapse Evolution). It has virtually the same cost as producing N-body-simulation initial conditions, since it works with the 'stretch' parameter {\\psi}, the Lagrangian divergence of the displacement field. It promises to be useful in quickly producing mock catalogs, and to simplify computationally intensive reconstructions of galaxy surveys. muscle applies a spherical-collapse prescription on multiple Gaussian-smoothed scales. It achieves higher accuracy than perturbative schemes (Zel'dovich and 2LPT), and, by including the void-in-cloud process (voids in large-scale collapsing regions), solves problems with a single-scale spherical-collapse scheme. Additionally, we show the behavior of {\\psi} for different morphologies (voids, walls, filaments, and haloes). A Python code to produce these realizations is availab...
On the generation of triaxiality in the collapse of cold spherical self-gravitating systems
Labini, Francesco Sylos; Joyce, Michael
2015-01-01T23:59:59.000Z
Initially cold and spherically symmetric self-gravitating systems may give rise to a virial equilibrium state which is far from spherically symmetric, and typically triaxial. We focus here on how the degree of symmetry breaking in the final state depends on the initial density profile. We note that the most asymmetric structures result when, during the collapse phase, there is a strong injection of energy preferentially into the particles which are localized initially in the outer shells. These particles are still collapsing when the others, initially located in the inner part, are already re-expanding; the motion of particles in a time varying potential allow them to gain kinetic energy --- in some cases enough to be ejected from the system. We show that this mechanism of energy gain amplifies the initial small deviations from perfect spherical symmetry due to finite $N$ fluctuations. This amplification is more efficient when the initial density profile depends on radius, because particles have a greater spr...
Broader source: Energy.gov [DOE]
This EA evaluates the environmental impacts of the proposal to support fusion physics development and technology, by providing an experimental device to investigate the confinement and performance...
Sandia National Laboratories: Facilities
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Sandia Solar Energy Test System Cited in National Engineering Competition On May 16, 2013, in Concentrating Solar Power, Energy, Energy Storage, Facilities, National Solar Thermal...
Sandia National Laboratories: ACEC
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ACEC Sandia Solar Energy Test System Cited in National Engineering Competition On May 16, 2013, in Concentrating Solar Power, Energy, Energy Storage, Facilities, National Solar...
Office of Energy Efficiency and Renewable Energy (EERE)
At the Clean Energy Manufacturing Initiative's (CEMI) 2015 National Summit, stakeholders are invited to share input on national priorities for clean energy manufacturing and explore models for...
None
2010-09-01T23:59:59.000Z
National Science Bowl finals and awards at the National Building Museum in Washington D.C. Monday 5/3/2010
Sandia National Laboratories: solar
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Interactive Tour Operated by Sandia National Laboratories for the U.S. Department of Energy (DOE), the National Solar Thermal Test Facility (NSTTF) is the only test facility...
National Laboratories - EERE Commercialization Office
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Laboratory Princeton Plasma Physics Laboratory Sandia National Laboratories Savannah River National Laboratory Stanford Linear Accelerator Center Thomas Jefferson National...
Photoplastic analysis of polycarbonate loaded by spherical indentator using strain-freezing method
Shimamoto, Akira [Saitama Institute of Technology (Japan); Umezaki, Eisaku [Nippon Institute of Technology, Saitama (Japan); Nogata, Fumio [Himeji Institute of Technology, Hyogo (Japan); Takahashi, Susumu [Kanto Gakuin Univ., Yokohama (Japan)
1996-12-31T23:59:59.000Z
Hardness test is one of the basic material testings. This investigates strain behavior in polycarbonate loaded by a spherical indentator using the strain-freezing method to establish a method of evaluating the material properties of polymers which have been widely used as machine parts and structural members because of a high elastic modulus and strength. As a result, the strain-freezing method was found to be effective for analyzing strains in polycarbonate loaded by a spherical indentator. Furthermore, the relation between the photoelastic fringe order and principal strain difference is found to be proportional as well as the relation between the total strain.
Magneto-inertial fusion with laser compression of a magnetized spherical target
Kostyukov, I. Yu., E-mail: kost@appl.sci-nnov.ru [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation); Ryzhkov, S. V., E-mail: ryzhkov@power.bmstu.ru [Bauman Moscow State Technical University (Russian Federation)
2011-12-15T23:59:59.000Z
The paper is devoted to the principles of magneto-inertial fusion and laser-plasma methods of generation of a Megagauss field during spherical implosion of a magnetized target. A model based on a magnetic confinement system, namely, a cusp configuration with inertial compression of the target by a laser driver, is developed. The dynamics of plasma in a cusp compressed under the effect of laser beams is precalculated. Analytical and numerical estimates of the particle number and magnetic field intensity during magneto-inertial plasma compression are obtained. The problems of irradiation of a spherically closed volume by a high-energy laser pulse are discussed.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41cloth Documentation DataDepartment of EnergyOn-Farm1 of 62.1 Print National Center0.1Lab NewsofBehavior of Impurity Ion
National Renewable Energy Laboratory
National Renewable Energy Laboratory Innovation for Our Energy Future ponsorship Format Reversed Color:White rtical Format Reversed-A ertical Format Reversed-B National Renewable Energy Laboratory National Renewable Energy Laboratory Innovation for Our Energy Future National Renewable Energy Laboratory
November 16, 1999 1. Drag force on non spherical particles. (25 points)
McCready, Mark J.
ChEg 355 Fall 1999 Test #2 November 16, 1999 1. Drag force on non spherical particles. (25 points) Recall that the Stokes' law drag relation for a sphere in creeping flow is: FD = 6 µ R U, where µ is the fluid viscosity, R is the radius of the sphere, and U is the terminal velocity. It was mentioned
Advanced Fluid Dynamics 2014 Sheet 5 Stokes flow around spherical particles
Hogg, Andrew
with no body force, where µ denotes the dynamic viscosity. Show that the stress tensor is given by ij = -2µ Ak xk ij + 2µ 2 xixj + xk 2 Ak xixj . (2) (b) Now consider the flow past a stationary sphere of radius the drag on the particle. 2. (a) Axisymmetric flow may be expressed in terms of spherical polar coordinates
Analytical Solution of the Forward Displacement Problem for Spherical Parallel Manipulators
Rodriguez, Jose
2012-01-01T23:59:59.000Z
In this paper, an analytical method that solves the forward displacement problem of several common spherical parallel manipulators (SPMs) is presented. The method uses the the quaternion algebra to restate the problem as a system of four quadrics in four variables and uses an algebraic geometry result by Dixon from 1908 to solve. In addition, a case study is presented for a specific SPM.
Comment on "Static and spherically symmetric black holes in f(R) theories"
S. Habib Mazharimousavi; M. Halilsoy
2012-10-17T23:59:59.000Z
We consider the interesting "near-horizon test" reported in (PRD84, 084006(2011), arXiv:1107.5727) for any static, spherically symmetric (SSS) black hole solution admitted in f(R) gravity. Before adopting the necessary conditions for the test, however, revisions are needed as we point out in this Comment.
Jablonowski, Christiane
Three Dimensional Adaptive Mesh Refinement on a Spherical Shell for Atmospheric Models for Atmospheric Research 1. Introduction One of the most important advances needed in global climate models of this project is a parallel adaptive grid library, which is currently under development at the University
Quantum chaos for the radially vibrating spherical billiard Richard L. Liboff and Mason A. Porter
Porter, Mason A.
Quantum chaos for the radially vibrating spherical billiard Richard L. Liboff and Mason A. Porter Chaos 17, 023116 (2007); 10.1063/1.2731307 Quantum Chaos in Billiards Comput. Sci. Eng. 9, 60 (2007); 10.1063/1.1322028 Vibrating soap films: An analog for quantum chaos on billiards Am. J. Phys. 66, 601 (1998); 10
Spheree: A 3D Perspective-Corrected Interactive Spherical Scalable Display Ferreira, F.q
British Columbia, University of
models can be exported or printed on a 3D printer. Other related 3D displays include: 1. pCubee [StavnessSpheree: A 3D Perspective-Corrected Interactive Spherical Scalable Display Ferreira, F.q , Cabral & U of British Columbia (a) (b) (c) (d) Figure 1: (a) A snowglobe; (b) a fish-tank animation; (c) a 3D
Spheree: A 3D Perspective-Corrected Interactive Spherical Scalable Display Ferreira, F.q
British Columbia, University of
in their applications or even print them with a 3D printer. Thus, Spheree plays a key role in realizing a completeSpheree: A 3D Perspective-Corrected Interactive Spherical Scalable Display Ferreira, F.q , Cabral to support head-coupled rendering to provide parallax-based 3D depth cues. Spheree is relatively compact
Boss, Emmanuel S.
-Pi measured roughly 0.5m diameter x 1 m long and did not incorporate batteries or computer; contrasted with LISST at 0.12 m dia x 0.7 m long, roughly 20 times smaller, yet complete with battery and data logger-spherical effects on backscatter. b. Characterization of scattering from terrigenous and biological size-sorted non
Farhad Ali
2014-12-30T23:59:59.000Z
In this paper we present Plane symmetric, Cylindrically Symmetric and Spherically Symmetric Black hole or Vacuum solutions of Einstein Field Equations(EFEs). Some of these solutions are new which we have not seen in the literature. This calculation will help us in understanding the gravitational wave and gravitational wave spacetimes.
Extended Soft Binding Mean Spherical- Contact Probability Approximation for Hard Ions
Blum, L. [Department of Mathematics, Rutgers University (United States); Arias, M.; Veloz, D. V. Perez [Physics Department, University of Puerto Rico (Puerto Rico)
2009-03-09T23:59:59.000Z
We propose a new analytical theory of electrolytes that extends the range of the Mean Spherical Approximation (MSA) to include extremely high charges [1, 2, 3, 4, 5]. In the MSA the thermodynamics and structure of the most general electrolyte are given in terms of a single screening parameter {gamma}, [1] which is obtained from the simple algebraic equation.
Calibration of broadband active acoustic systems using a single standard spherical target
Stanton, Tim
Calibration of broadband active acoustic systems using a single standard spherical target Timothy K 8 April 2008 When calibrating a broadband active acoustic system with a single standard target the concept of using this echo for calibration in the work of Dragonette et al. J. Acoust. Soc. Am. 69, 1186
Water-like solvation thermodynamics in a spherically symmetric solvent model
Buldyrev, Sergey
Water-like solvation thermodynamics in a spherically symmetric solvent model with two. The Jagla fluid has been recently shown to possess water-like structural, dynamic, and thermodynamic and thereby show that the Jagla fluid also displays water-like solvation thermodynamics. We further find low
The giant luminous arc Statistics. II. spherical lens models based on ROSAT HRI data
Kohji Molikawa; Makoto Hattori; Jean-Paul Kneib; Kazuyuki Yamashita
1999-09-10T23:59:59.000Z
We present ROSAT HRI X-ray observations of all the galaxy clusters in the Le F\\`evre et al. arc survey sample in order to study the spatial distribution of the intra-cluster medium, and examine the expected number of giant luminous arcs for the sample using two spherically symmetric lens models constrained by our X-ray data.
Fusion Engineering and Design 5152 (2000) 325330 Nuclear issues and analysis for ARIES spherical and
California at San Diego, University of
2000-01-01T23:59:59.000Z
Fusion Engineering and Design 5152 (2000) 325330 Nuclear issues and analysis for ARIES spherical the key nuclear parameters for both designs. Preceding the 3-D analysis, a series of parametric 1-D analysis using the DANTSYS code [4] was established to guide the design pro- cess. The data library
Sánchez, Juan
by differentially-heated solid spherical shells is mainly considered. Asymptotic power laws for the mean physical and compositional buoy- ancy forces (Lister and Buffet (1995); Poirier (2000)) in this paper we focus on the imprint- tial bodies. Good reviews can be found in the literature, see for instance Cardin and Olson (1994
Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing 100871 (China)
2011-02-15T23:59:59.000Z
Large discrepancies among the laminar flame speeds and Markstein lengths of methane/air mixtures measured by different researchers using the same constant-pressure spherical flame method are observed. As an effort to reduce these discrepancies, one linear model (LM, the stretched flame speed changes linearly with the stretch rate) and two non-linear models (NM I and NM II, the stretched flame speed changes non-linearly with the stretch rate) for extracting the laminar flame speed and Markstein length from propagating spherical flames are investigated. The accuracy and performance of the LM, NM I, and NM II are found to strongly depend on the Lewis number. It is demonstrated that NM I is the most accurate for mixtures with large Lewis number (positive Markstein length) while NM II is the most accurate for mixtures with small Lewis number (negative Markstein length). Therefore, in order to get accurate laminar flame speed and Markstein length from spherical flame experiments, different non-linear models should be used for different mixtures. The validity of the theoretical results is further demonstrated by numerical and experimental studies. The results of this study can be used directly in spherical flame experiments measuring the laminar flame speed and Markstein length. (author)
Walter, M.Todd
The spherically symmetric droplet burning characteristics of Jet-A and biofuels derived from the biofuels due to its higher aromatic content. " Droplet burning rates of camelina and tallow HRJ fuel Available online 1 March 2013 Keywords: Alternative jet fuel Hydroprocessed biofuel Spherically symmetric
Sengun, Mehmet Haluk
Spherical Tokamak J. R. Robinson1, B. Hnat1, P. Dura1, A. Kirk2, P. Tamain3, A. Thyagaraja4, K. G. Mc Acoustic Mode (GAM) at the edge of an Ohmic plasma on the Mega Amp Spherical Tokamak (MAST). A strong 10 k
Consent Order, Lawrence Livermore National National Security...
for deficiencies associated with the Lawrence Livermore National Laboratory Chronic Beryllium Disease Prevention Program On October 29, 2010, the U.S. Department of Energy (DOE)...
Sandia National Laboratories: National Renewable Energy Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
Sandia National Laboratories: Jawaharlal Nehru Solar National...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Jawaharlal Nehru Solar National Solar Energy Mission Solar Energy Research Institute for India and the United States Kick-Off On November 27, 2012, in Concentrating Solar Power,...
Synthesis of spherical LiMnPO{sub 4}/C composite microparticles
Bakenov, Zhumabay [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)] [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Taniguchi, Izumi, E-mail: taniguchi.i.aa@m.titech.ac.jp [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)] [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)
2011-08-15T23:59:59.000Z
Highlights: {yields} We could prepare LiMnPO{sub 4}/C composites by a novel preparation method. {yields} The LiMnPO{sub 4}/C composites were spherical particles with a mean diameter of 3.65 {mu}m. {yields} The LiMnPO{sub 4}/C composite cathode exhibited 112 mAh g{sup -1} at 0.05 C. {yields} It also showed a good rate capability up to 5 C at room temperature and 55 {sup o}C. -- Abstract: Spherical LiMnPO{sub 4}/C composite microparticles were prepared by a combination of spray pyrolysis and spray drying followed by heat treatment and examined as a cathode material for lithium batteries. The structure, morphology and electrochemical performance of the resulting spherical LiMnPO{sub 4}/C microparticles were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electronic microscopy and standard electrochemical techniques. The final sample was identified as a single phase orthorhombic structure of LiMnPO{sub 4} and spherical powders with a geometric mean diameter of 3.65 {mu}m and a geometric standard deviation of 1.34. The electrochemical cells contained the spherical LiMnPO{sub 4}/C microparticles exhibited first discharge capacities of 112 and 130 mAh g{sup -1} at 0.05 C at room temperature and 55 {sup o}C, respectively. These also showed a good rate capability up to 5 C at room temperature and 55 {sup o}C.
Ames Laboratory Argonne National Laboratory
Renewable Energy Laboratory Golden, Colorado Oak Ridge National Laboratory Oak Ridge, Tennessee Pacific National Laboratory Livermore, California Los Alamos National Laboratory Los Alamos, New Mexico National Energy Technology Laboratory Morgantown, West Virginia Pittsburgh, Pennsylvania Albany, Oregon National
Argonne National Laboratory's Nondestructive
Kemner, Ken
Argonne National Laboratory's Nondestructive Evaluation Technologies NDE #12;Over45yearsexperienceinNondestructiveEvaluation... Argonne National Laboratory's world-renowned researchers have a proven the safe operationof advanced nuclear reactors. Argonne's World-Class Nondestructive Evaluation
National Energy Education Summit
Broader source: Energy.gov [DOE]
The National Energy Education Summit is organized by the Council of Energy Research and Education Leaders (CEREL) and will serve as a first-of-its-kind national forum for energy educators, subject...
Sandia National Laboratories: AREVA
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Concentrating Solar Power, Energy, Energy Storage, Facilities, National Solar Thermal Test Facility, News, News & Events, Partnership, Renewable Energy, Research &...
Sandia National Laboratories: Facilities
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Laboratory (PSEL) National Supervisory Control and Data Acquisition (SCADA) Test Bed Center for Integrated Nanotechnologies (CINT) Distributed Energy Technologies Laboratory...
Broader source: Energy.gov [DOE]
High-resolution map produced by Oak Ridge National Laboratory showing hydropower resources throughout the United States.
Los Alamos National Security, LLC Los Alamos National Laboratory...
Office of Environmental Management (EM)
Security, LLC Los Alamos National Laboratory (LANL) Voluntary Protection Program (VPP) Assessment Los Alamos National Security, LLC Los Alamos National Laboratory (LANL) Voluntary...
Sandia National Laboratories: National Solar Thermal Test Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
EnergySolar EnergyConcentrating Solar Power (CSP)National Solar Thermal Test Facility National Solar Thermal Test Facility NSTTF Interactive Tour National Solar...
NATIONAL HYDROGEN ENERGY ROADMAP
NATIONAL HYDROGEN ENERGY ROADMAP NATIONAL HYDROGEN ENERGY ROADMAP . . Toward a More Secure and Cleaner Energy Future for America Based on the results of the National Hydrogen Energy Roadmap Workshop to make it a reality. This Roadmap provides a framework that can make a hydrogen economy a reality
Pacific Northwest National Laboratory
Pacific Northwest National Laboratory Operated by Battelle for the U.S. Department of Energy Operations (MRO) provides research and develop ment to meet national needs. Located at the mouth of Sequim Northwest National Laboratory (PNNL) operated by Battelle Memorial Institute. Battelle has a unique contract
texts of standards Indexes to millions of industry, national, regional, and international standards U for Standards and Certification Information (NCSCI) National Institute of Standards and Technology (NIST) 100.975.4040 for an appointment, Monday-Friday, 8:30 a.m.5:00 p.m. (except Federal holidays). National Institute of Standards
Marushka, Viktor; Zabeida, Oleg, E-mail: oleg.zabeida@polymtl.ca; Martinu, Ludvik [Engineering Physics Department, Polytechnique Montréal, P.O. Box 6079, Downtown station, Montreal, Quebec H3C 3A7 (Canada)
2014-11-01T23:59:59.000Z
The uniformity of ion density is critical for applications relying on the ion assisted deposition technique for the fabrication of the high quality thin films. The authors propose and describe here a method allowing one to calculate the ion density distribution on spherical substrate holders under stationary and rotating conditions for different positions of the ion source. The ion beam shape was approximated by a cos{sup n} function, and the ion current density was represented by a function inversely proportional to the distance from the ion source in accordance with our experimental results. As an example, a calculation of the current density distribution on the spherical cap substrate was performed for a broad beam ion source operated with an anode current of 3?A. The authors propose an approach for process optimization with respect to the ion source position and its inclination, in terms of uniformity and absolute value of the ion current density.
T. Thiemann
1999-10-04T23:59:59.000Z
We present here the canonical treatment of spherically symmetric (quantum) gravity coupled to spherically symmetric Maxwell theory with or without a cosmological constant. The quantization is based on the reduced phase space which is coordinatized by the mass and the electric charge as well as their canonically conjugate momenta, whose geometrical interpretation is explored. The dimension of the reduced phase space depends on the topology chosen, quite similar to the case of pure (2+1) gravity. We also compare the reduced phase space quantization to the algebraic quantization. Altogether, we observe that the present model serves as an interesting testing ground for full (3+1) gravity. We use the new canonical variables introduced by Ashtekar which simplifies the analysis tremendously.
T. Thiemann
1999-10-04T23:59:59.000Z
We extend here the canonical treatment of spherically symmetric (quantum) gravity to the most simple matter coupling, namely spherically symmetric Maxwell theory with or without a cosmological constant. The quantization is based on the reduced phase space which is coordinatized by the mass and the electric charge as well as their canonically conjugate momenta, whose geometrical interpretation is explored. The dimension of the reduced phase space depends on the topology chosen, quite similar to the case of pure (2+1) gravity. We investigate several conceptual and technical details that might be of interest for full (3+1) gravity. We use the new canonical variables introduced by Ashtekar, which simplifies the analysis tremendously.
Packing of softly repulsive particles in a spherical box - a generalised Thomson problem
A. Mughal
2013-06-12T23:59:59.000Z
We study the (near or close to) ground state distribution of N softly repelling particles trapped in the interior of a spherical box. The charges mutually interact via an inverse power law potential of the form $1/r^\\gamma$. We study three regimes in which the charges form an single spherical shell at the edge of the box ($\\gamma=1$), a series of concentric shells of increasing density ($\\gamma=2$) and $\\gamma=12$ for which the charges form shells with a more uniform charge distribution. We conduct numerical simulations for clusters containing up to 5000 charges and compare charge density across the system with continuum limit results. The agreement between numerical (discrete) results and the continuum limit is found to improve with increasing N.
Non-Singular Spherically Symmetric Solution in Einstein-Scalar-Tensor Gravity
J. W. Moffat
2008-06-11T23:59:59.000Z
A static spherically symmetric metric in Einstein-scalar-tensor gravity theory with a scalar field potential $V[\\phi]$ is non-singular for all real values of the coordinates. It does not have a black hole event horizon and there is no essential singularity at the origin of coordinates. The weak energy condition $\\rho_\\phi > 0$ fails to be satisfied for $r\\lesssim 1.3r_S$ (where $r_S$ is the Schwarzschild radius) but the strong energy condition $\\rho_\\phi+3p_\\phi > 0$ is satisfied. The classical Einstein-scalar-tensor solution is regular everywhere in spacetime without a black hole event horizon. However, the violation of the weak energy condition may signal the need for quantum physics anti-gravity as $r\\to 0$. The non-singular static spherically symmetric solution is stable against the addition of ordinary matter.
Light-emitting diode spherical packages: an equation for the light transmission efficiency
Moreno, Ivan; Avendano-Alejo, Maximino; 10.1364/AO.49.000012
2011-01-01T23:59:59.000Z
Virtually all light-emitting diodes (LEDs) are encapsulated with a transparent epoxy or silicone-gel. In this paper we analyze the optical efficiency of spherical encapsulants. We develop a quasi-radiometric equation for the light transmission efficiency, which incorporates some ideas of Monte-Carlo ray tracing into the context of radiometry. The approach includes the extended source nature of the LED chip, and the chip radiance distribution. The equation is an explicit function of the size and the refractive index of the package, and also of several chip parameters such as shape, size, radiance, and location inside the package. To illustrate the use of this equation, we analyze several packaging configurations of practical interest; for example, a hemispherical dome with multiple chips, a flat encapsulation as a special case of the spherical package, and approximate calculations of an encapsulant with a photonic crystal LED or with a photonic quasi crystal LED. These calculations are compared with Monte-Carl...
Development of a Thermodynamic Model for Fluids Confined in Spherical Pores
D'Lima, Michelle Lynn
2014-07-18T23:59:59.000Z
follows the Linde type A (LTA) structure ..................................... 26 Figure 6: Sodalite17 follows the SOD structure† .............................................................. 26 Figure 7: Chabazite17 follows the SSZ-13 structure... components of natural gas. Both pure component and binary mixture literature data were compiled. 25 Table 3: Spherical Zeolite Classification Structure Name ASV ASU-7 ATN MAPO-39 DDR Deca-dodecasile 3R DFT DAF-2 LTL Linde Type L, zeolite...
A spherically symmetric and stationary universe from a weak modification of general relativity
Christian Corda; Herman J. Mosquera Cuesta
2009-04-01T23:59:59.000Z
It is shown that a weak modification of general relativity, in the linearized approach, renders a spherically symmetric and stationary model of the universe. This is due to the presence of a third mode of polarization in the linearized gravity in which a "curvature" energy term is present. Such an energy can, in principle, be identified as the Dark Energy. The model can also help to a better understanding of the framework of the Einstein-Vlasov system.
The Energy Distribution in a Static Spherically Symmetric Nonsingular Black Hole Space-Time
I. Radinschi
2000-08-14T23:59:59.000Z
We calculate the energy distribution in a static spherically symmetric nonsingular black hole space-time by using the Tolman's energy-momentum complex. All the calculations are performed in quasi-Cartesian coordinates. The energy distribution is positive everywhere and be equal to zero at origin. We get the same result as obtained by Y-Ching Yang by using the Einstein's and Weinberg's prescriptions.
Adler, Thomas A. (Corvallis, OR)
1996-01-01T23:59:59.000Z
The invention pertains a method of determining elastic and plastic mechanical properties of ceramics, intermetallics, metals, plastics and other hard, brittle materials which fracture prior to plastically deforming when loads are applied. Elastic and plastic mechanical properties of ceramic materials are determined using spherical indenters. The method is most useful for measuring and calculating the plastic and elastic deformation of hard, brittle materials with low values of elastic modulus to hardness.
Static spherically symmetric perfect fluid solutions in $f(R)$ theories of gravity
T. Multamaki; I. Vilja
2006-12-29T23:59:59.000Z
Static spherically symmetric perfect fluid solutions are studied in metric $f(R)$ theories of gravity. We show that pressure and density do not uniquely determine $f(R)$ ie. given a matter distribution and an equation state, one cannot determine the functional form of $f(R)$. However, we also show that matching the outside Schwarzschild-de Sitter-metric to the metric inside the mass distribution leads to additional constraints that severely limit the allowed fluid configurations.
Francine Luppé; Jean-Marc Conoir; Andrew N. Norris
2011-10-06T23:59:59.000Z
The dispersion relation is derived for the coherent waves in fluid or elastic media supporting viscous and thermal effects and containing randomly distributed spherical scatterers. The formula obtained is the generalization of Lloyd and Berry's [Proc. Phys. Soc. Lond. 91, 678-688, 1067], the latter being limited to fluid host media, and it is the three-dimensional counterpart of that derived by Conoir and Norris [Wave Motion 47, 183-197, 2010] for cylindrical scatterers in an elastic host medium.
Thermal stability of a spherical shell heated by convection and cooled by boiling
Qaim-Maqami, Hassan
1973-01-01T23:59:59.000Z
such high heat transfer rates by forced convection would require extremely high veloc- ities with subsequent high pressure dropsy With nuclee, boiling, however, such high heat transfe. rates an be obtained at much smaller velocities. Boiling heat...THERMAL STABILITY OF A. SPHERICAL SHELL HEATED BY CONVECTION AND COOLED BY BOILING A Thesis HASSAN @AIM-MAQAMI Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...
Spherically symmetric self-similar solutions and their astrophysical and cosmological applications
B. J. Carr
2000-03-02T23:59:59.000Z
We discuss spherically symmetric perfect fluid solutions of Einstein's equations which have equation of state ($p=\\alpha \\mu$) and which are self-similar in the sense that all dimensionless variables depend only upon $z\\equiv r/t$. For each value of $\\alpha$, such solutions are described by two parameters and have now been completely classified. There is a 1-parameter family of solutions asymptotic to the flat Friedmann model at large values of z. These represent either black holes or density perturbations which grow as fast as the particle horizon; the underdense solutions may be relevant to the existence of large-scale cosmic voids. There is also a 1-parameter family of solutions asymptotic to a self-similar Kantowski-Sachs model at large z. These are probably only physically realistic for $-11/5$, there is a family of solutions which are asymptotically Minkowski. These asymptote either to infinite z, in which case they are described by one parameter, or to a finite value of z, in which case they are described by two parameters and this includes the ``critical'' solution for $\\alpha >0.28$. We discuss the stability of spherically symmetric similarity solutions to more general (non-self-similar) spherically symmetric perturbations.
Linear analysis on the growth of non-spherical perturbations in supersonic accretion flows
Takahashi, Kazuya; Yamada, Shoichi, E-mail: ktakahashi@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku 169-8555 (Japan)
2014-10-20T23:59:59.000Z
We analyzed the growth of non-spherical perturbations in supersonic accretion flows. We have in mind an application to the post-bounce phase of core-collapse supernovae (CCSNe). Such non-spherical perturbations have been suggested by a series of papers by Arnett, who has numerically investigated violent convections in the outer layers of pre-collapse stars. Moreover, Couch and Ott demonstrated in their numerical simulations that such perturbations may lead to a successful supernova even for a progenitor that fails to explode without fluctuations. This study investigated the linear growth of perturbations during the infall onto a stalled shock wave. The linearized equations are solved as an initial and boundary value problem with the use of a Laplace transform. The background is a Bondi accretion flow whose parameters are chosen to mimic the 15 M {sub ?} progenitor model by Woosley and Heger, which is supposed to be a typical progenitor of CCSNe. We found that the perturbations that are given at a large radius grow as they flow down to the shock radius; the density perturbations can be amplified by a factor of 30, for example. We analytically show that the growth rate is proportional to l, the index of the spherical harmonics. We also found that the perturbations oscillate in time with frequencies that are similar to those of the standing accretion shock instability. This may have an implication for shock revival in CCSNe, which will be investigated in our forthcoming paper in more detail.
Program Areas | National Security | ORNL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Organizations National Security Home | Science & Discovery | National Security | Program Areas SHARE Program Areas image Oak Ridge National Laboratory (ORNL) has a robust...
Review: Manufacturing National Park Nature
Mason, Fred
2012-01-01T23:59:59.000Z
Review: Manufacturing National Park Nature: Photography,Canada Cronin, J. Keri. Manufacturing National Park Nature:J. Keri Cronin’s book Manufacturing National Park Nature
Climate Change and National Security
Alyson, Fleming; Summer, Kelly; Summer, Martin; Lauren, Franck; Jonathan, Mark
2015-01-01T23:59:59.000Z
for Environment and National Security Scripps Institution ofMultiplying Threats to National Security Higher temperaturesefforts to protect national security. Page 2 The U.S. Armed
Bisnovatyi-Kogan, G S
2015-01-01T23:59:59.000Z
In this paper we review a recently developed approximate method for investigation of dynamics of compressible ellipsoidal figures. Collapse and subsequent behaviour are described by a system of ordinary differential equations for time evolution of semi-axes of a uniformly rotating, three-axis, uniform-density ellipsoid. First, we apply this approach to investigate dynamic stability of non-spherical bodies. We solve the equations that describe, in a simplified way, the Newtonian dynamics of a self-gravitating non-rotating spheroidal body. We find that, after loss of stability, a contraction to a singularity occurs only in a pure spherical collapse, and deviations from spherical symmetry prevent the contraction to the singularity through a stabilizing action of nonlinear non-spherical oscillations. The development of instability leads to the formation of a regularly or chaotically oscillating body, in which dynamical motion prevents the formation of the singularity. We find regions of chaotic and regular pulsat...
Arrieta, Eduardo
1986-01-01T23:59:59.000Z
SPHERICAL APPROXIMATION A Thesis by EDUARDO ARRIETA Approved as to style and content by: James C. Holste (Co-Chairman of Committee) Kenneth N. Marsh (Co- airman of Committee) Czeslaw J9 sejek (Member) harles . Hollan (Head of Department... (Spain) Co-Chairmen of Advisory Committee: James C. Holste Kenneth iV. Marsh The Blum and Hziye analysis of the mean spherical approximation (MSA) for binary mixtures of hard core fluids with single Yukawa interactions is brought to its final form: a...
Xudong Liang; Shengqiang Cai
2015-05-29T23:59:59.000Z
Under the actions of internal pressure and electric voltage, a spherical dielectric elastomer balloon usually keeps a sphere during its deformation, which has also been assumed in many previous studies. In this article, using linear perturbation analysis, we demonstrate that a spherical dielectric elastomer balloon may bifurcate to a non-spherical shape under certain electromechanical loading conditions. We also show that with a non-spherical shape, the dielectric elastomer balloon may have highly inhomogeneous electric field and stress/stretch distributions, which can lead to the failure of the system. In addition, we conduct stability analysis of the dielectric elastomer balloon in different equilibrium configurations by evaluating its second variation of free energy under arbitrary perturbations. Our analyses indicate that under pressure-control and voltage-control mode, non-spherical deformation of the dielectric elastomer balloon is energetically unstable. However, under charge-control or ideal gas mass-control mode, non-spherical deformation of the balloon is energetically stable.
Xudong Liang; Shengqiang Cai
2015-06-12T23:59:59.000Z
Under the actions of internal pressure and electric voltage, a spherical dielectric elastomer balloon usually keeps a sphere during its deformation, which has also been assumed in many previous studies. In this article, using linear perturbation analysis, we demonstrate that a spherical dielectric elastomer balloon may bifurcate to a non-spherical shape under certain electromechanical loading conditions. We also show that with a non-spherical shape, the dielectric elastomer balloon may have highly inhomogeneous electric field and stress/stretch distributions, which can lead to the failure of the system. In addition, we conduct stability analysis of the dielectric elastomer balloon in different equilibrium configurations by evaluating its second variation of free energy under arbitrary perturbations. Our analyses indicate that under pressure-control and voltage-control mode, non-spherical deformation of the dielectric elastomer balloon is energetically unstable. However, under charge-control or ideal gas mass-control mode, non-spherical deformation of the balloon is energetically stable.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Events and Conferences Supporting Organizations A scientific approach to global security Initiatives | Programs Home | Science & Discovery | National Security National...
Overview of the preliminary safety analysis of the National Ignition Facility
Brereton, S.; McLouth, L.; Odell, B. [Lawrence Livermore National Lab., CA (United States)] [and others] [Lawrence Livermore National Lab., CA (United States); and others
1997-06-01T23:59:59.000Z
The National Ignition Facility (NIF) is a proposed U.S. Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, New Mexico, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 individual laser beams onto a tiny deuterium-tritium target located at the center of a spherical target chamber. The NIF has been classified as a low hazard, radiological facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis report be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A Preliminary Safety Analysis Report (PSAR) has been approved, which documents and evaluates the safety issues associated with the construction, operation, and decommissioning of the NIF. 10 refs., 6 figs., 4 tabs.
National Security Campus | National Nuclear Security Administration
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Co - PA 40 FUSRAPChupadera? r . . WOur Mission /Our Mission /National| National
National Postdoctoral Association | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNational 2 ContentsworkNational
NATIONAL SECURITY TECHNOLOGIES - NEVADA NATIONAL SECURITY SITE
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020, 029, 0049,NASA | National Nuclear SecurityNATIONAL
ARGONNE NATIONAL LABORATORY May
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ARGONNE NATIONAL LABORATORY May 9, 1994 Light Source Note: LS234 Comparison of the APS and UGIMAG Helmholtz Coil Systems David W. Carnegie Accelerator Systems Division Advanced...
Procurement | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Procurement More than 150 attend second joint Argonne-Fermilab small business fairSeptember 2, 2014 On Thursday, Aug. 28, Illinois' two national laboratories - Argonne and Fermi...
Sandia National Laboratories: Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
& Events, Partnership, Renewable Energy, Solar, Solar Newsletter SolarReserve is testing engineering units at the National Solar Thermal Test Facility (NSTTF) operated by Sandia....
Sandia National Laboratories: NSTTF
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
& Events, Partnership, Renewable Energy, Solar, Solar Newsletter SolarReserve is testing engineering units at the National Solar Thermal Test Facility (NSTTF) operated by Sandia....
Los Alamos National Laboratory
National Nuclear Security Administration (NNSA)
for national defense and homeland security programs; and U.S. Department of Energy (DOE) waste management activities. The Plutonium Facility at Technical Area 55 (TA-55) is...
Sandia National Laboratories: photovoltaic
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
... Photovoltaic Technology and Tour of PV Test Facilities On February 12, 2013, in The Photovoltaics and Distributed Systems Integration Department at Sandia National...
Sandia National Laboratories: PV
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
... Photovoltaic Technology and Tour of PV Test Facilities On February 12, 2013, in The Photovoltaics and Distributed Systems Integration Department at Sandia National...
None
2013-03-01T23:59:59.000Z
Ames Laboratory observed the National Day of Remembrance for weapons workers from the Cold War era with a ceremony held Oct. 27, 2009 at the Ames Public Library.
Sandia National Laboratories Problem
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Sandia National Laboratories Problem Natural disasters such as Hurricane Katrina in New Orleans and the tsunami in Japan in 2011 create emergency situations that must be dealt with...
Sandia National Laboratories: Partnership
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Armstrong using deep level optical spectroscopy to investigate defects in the m-plane GaN. Jim is a professor ... Vermont and Sandia National Laboratories Announce Energy...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Laboratory are developing materials and techniques used to fabricate solid oxide fuel cells. This test of a "button" cell will help select electrode materials for...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
VPPPA Conference August 19, 2012 Subcontractor Selection & Alignment Mark Manderbach, Steve Maki, J. Manuel Aguirre National VPPPA Conference August 19, 2012 Mark Manderbach, Steve...
Los Alamos National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Department of Energy environmental sustainability award October 14, 2010 LOS ALAMOS, New Mexico, October 14, 2010-Los Alamos National Laboratory recently received an Environmental...
National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Washington, DC 20585 MEMORANDUM FOR THE ADMINISTRATOR FROM: THEODORE D. SHERRY II 4 flA. * -. SUBJECT: REFERENCE: NATIONAL SECURITY ENTI's'E FIELD COUNCIL CHAIR ACTION:...
National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Project Reviews, etc., except those specifically reserved for the Administrator for the National Nuclear Security Administration and the Deputy Secretary. cc: Mike Hickman. NA-Stl...
Sandia National Laboratories: Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
10-11, 2012 at Sandia National Laboratories, Albuquerque, NM. The review covered seven agreement areas: Optical Materials and Tools, System Analysis, Trough Performance Testing,...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
30 nonprofit organizations to receive monetary donations from Los Alamos National Security, LLC June 25, 2012 Recognizing employee and retiree volunteer efforts LOS ALAMOS, NEW...
None
2010-01-01T23:59:59.000Z
Ames Laboratory observed the National Day of Remembrance for weapons workers from the Cold War era with a ceremony held Oct. 27, 2009 at the Ames Public Library.
Sandia National Laboratories: FCEV
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
Sandia National Laboratories: Modeling
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
Sandia National Laboratories: Capabilities
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
Sandia National Laboratories: HRSAM
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
Sandia National Laboratories: NREL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and the National Renewable Energy Laboratory (NREL) announce the publication of two new Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) reports on...
National Women's History Month
Broader source: Energy.gov [DOE]
NATIONAL WOMEN’S HISTORY MONTH is an annual declared month that highlights the contributions of women to events in history and contemporary society.
Office of Energy Efficiency and Renewable Energy (EERE)
RES Las Vegas is another multifaceted event from The National Center which will feature unparalleled access to respected tribal leaders, members of congress, federal agency representatives, state...
Sandia National Laboratories: photovoltaic
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Energy Security National Solar Thermal Test Facility NSTTF Nuclear Energy photovoltaic Photovoltaics PV Renewable Energy solar Solar Energy solar power Solar Research...
Sandia National Laboratories: photovoltaic
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
MEPV Awards Researchers at Sandia National Laboratories are pioneering solar photovoltaic (PV) technologies that are cheaper to produce and easier to install than...
Sandia National Laboratories: performance
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
performance Photovoltaic (PV) Regional Test Center (RTC) Website Goes Live On February 26, 2013, in Energy, National Solar Thermal Test Facility, News, News & Events, Partnership,...
National Laboratory Photovoltaics Research
Broader source: Energy.gov [DOE]
DOE supports photovoltaic (PV) research and development and facilities at its national laboratories to accelerate progress toward achieving the SunShot Initiative's technological and economic...
Unconstrained hyperboloidal evolution of black holes in spherical symmetry with GBSSN and Z4c
Alex Vañó-Viñuales; Sascha Husa
2014-12-15T23:59:59.000Z
We consider unconstrained evolution schemes for the hyperboloidal initial value problem in numerical relativity as a promising candidate for the optimally efficient numerical treatment of radiating compact objects. Here, spherical symmetry already poses nontrivial problems and constitutes an important first step to regularize the resulting singular PDEs. We evolve the Einstein equations in their generalized BSSN and Z4 formulations coupled to a massless self-gravitating scalar field. Stable numerical evolutions are achieved for black hole initial data, and critically rely on the construction of appropriate gauge conditions.
Gusakov, E; Gusakov, Evgeniy; Surkov, Alexander
2004-01-01T23:59:59.000Z
The parametric instability of upper hybrid wave decay into back scattered upper hybrid wave and lower hybrid wave is considered for conditions of inhomogeneous plasma of spherical tokamaks. The possibility of absolute instability is demonstrated and the corresponding threshold is determined. It is shown that the threshold power increases with pump frequency and electron temperature. Threshold power is estimated for typical parameters of experiment in MAST tokamak. It is shown that in this case parametrical reflection arises, if probing power exceeds 129W/cm^2, which gives 40 kW for a beam of 10 cm radius.
Discontinuous Galerkin method for the spherically reduced BSSN system with second-order operators
Scott E. Field; Jan S. Hesthaven; Stephen R. Lau; Abdul H. Mroue
2010-12-18T23:59:59.000Z
We present a high-order accurate discontinuous Galerkin method for evolving the spherically-reduced Baumgarte-Shapiro-Shibata-Nakamura (BSSN) system expressed in terms of second-order spatial operators. Our multi-domain method achieves global spectral accuracy and long-time stability on short computational domains. We discuss in detail both our scheme for the BSSN system and its implementation. After a theoretical and computational verification of the proposed scheme, we conclude with a brief discussion of issues likely to arise when one considers the full BSSN system.
A detailed study of collisionless explosion of single- and two-ion-species spherical nanoplasmas
Popov, K. I. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Bychenkov, V. Yu. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Rozmus, W. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Ramunno, L. [Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada)
2010-08-15T23:59:59.000Z
The collisionless adiabatic expansion into vacuum of spherical plasma targets (clusters) composed of cold single- or multispecies ions and hot electrons is studied kinetically by numerical solving of the nonrelativistic equations of motion of plasma particles in the self-consistent electrostatic field. The expansion dynamics for the whole range of electron temperatures from much less than to much higher than the cluster Coulomb energy is described for various initial plasma density profiles and cluster structures. The explosion of two ion species heterogeneous (layered) and homogeneously mixed targets is studied in detail for the wide range of light ion concentration and kinematic parameter.
Explicit Solution of Worst-Case Secrecy Rate for MISO Wiretap Channels with Spherical Uncertainty
Li, Jiangyuan
2011-01-01T23:59:59.000Z
A multiple-input single-output (MISO) wiretap channel model is considered, that includes a multi-antenna transmitter, a single-antenna legitimate receiver and a single-antenna eavesdropper. For the scenario in which spherical uncertainty for both the legitimate and the eavesdropper channels is included, the problem of finding the optimal input covariance that maximizes the worst-case secrecy rate subject to a power constraint, is considered, and an explicit expression for the maximum worst-case secrecy rate is provided.
Sphericity and symmetry breaking in the formation of frank-kasper phases
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect JournalPentoxide.Conference: to(Conference)(TechnicalBeamsLongitudinalSpherical geodesic
Sphericity and symmetry breaking in the formation of frank-kasper phases
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect JournalPentoxide.Conference: to(Conference)(TechnicalBeamsLongitudinalSpherical geodesicfrom
Laser-Driven Shock Acceleration of Ion Beams from Spherical Mass-Limited Targets
Henig, A.; Kiefer, D.; Hoerlein, R.; Major, Zs.; Krausz, F.; Habs, D. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Garching (Germany); Geissler, M. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Rykovanov, S. G. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Moscow Physics Engineering Institute, Kashirskoe shosse 31, Moscow (Russian Federation); Ramis, R. [ETSI Aeronauticos, Universidad Politecnica de Madrid (Spain); Osterhoff, J.; Veisz, L.; Karsch, S. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Schreiber, J. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Garching (Germany); Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)
2009-03-06T23:59:59.000Z
We report on experimental studies of ion acceleration from spherical targets of diameter 15 {mu}m irradiated by ultraintense (1x10{sup 20} W/cm{sup 2}) pulses from a 20-TW Ti:sapphire laser system. A highly directed proton beam with plateau-shaped spectrum extending to energies up to 8 MeV is observed in the laser propagation direction. This beam arises from acceleration in a converging shock launched by the laser, which is confirmed by 3-dimensional particle-in-cell simulations. The temporal evolution of the shock-front curvature shows excellent agreement with a two-dimensional radiation pressure model.
In-medium nucleon-nucleon cross-sections with non-spherical Pauli blocking
L. White; F. Sammarruca
2014-06-14T23:59:59.000Z
We present a formalism to solve the Bethe-Goldstone scattering equation without the use of partial wave expansion which is alternative to the one we developed in a previous work. The present approach is more suitable for the calculation of in-medium nucleon-nucleon cross sections, which are the focal point of this paper. The impact of removing the spherical approximation on the angle and energy dependence of, particularly, in-medium proton-proton and proton-neutron differential cross sections is discussed along with its potential implication.
Testing the neutrality of matter by acoustic means in a spherical resonator
Bressi, G.; Carugno, G.; Della Valle, F.; Galeazzi, G.; Ruoso, G.; Sartori, G. [INFN, Sezione di Pavia, Via U. Bassi 6, I-27100 Pavia (Italy); INFN, Sezione di Padova, Via F. Marzolo 8, I-35131 Padova (Italy); Dipartimento di Fisica, Universita di Trieste and INFN, Sezione di Trieste, Via A. Valerio 2, I-34127 Trieste (Italy); INFN, Laboratori Nazionali di Legnaro, Viale dell'Universita 2, I-35020 Legnaro (PD) (Italy); INFN, Sezione di Padova and Dipartimento di Fisica, Universita di Padova, Via F. Marzolo 8, I-35131 Padova (Italy)
2011-05-15T23:59:59.000Z
Measurements to test the neutrality of matter by acoustic means are reported. The apparatus is based on a spherical capacitor filled with gaseous SF{sub 6} excited by an oscillating electric field. The apparatus has been calibrated measuring the electric polarizability. Assuming charge conservation in the {beta} decay of the neutron, the experiment gives a limit of {epsilon}{sub p-e} < or approx. 1x10{sup -21} for the electron-proton charge difference, the same limit holding for the charge of the neutron. Previous measurements are critically reviewed and found to be inaccurate.
On spherically symmetric metric satisfying the positive kinetic energy coordinate condition
T. Mei
2008-02-28T23:59:59.000Z
Generally speaking, there is a negative kinetic energy term in the Lagrangian of the Einstein-Hilbert action of general relativity; On the other hand, the negative kinetic energy term can be vanished by designating a special coordinate system. For general spherically symmetric metric, the question that seeking special coordinate system that satisfies the positive kinetic energy coordinate condition is referred to solving a linear first-order partial differential equation. And then, we present a metric corresponding to the Reissner-Nordstrom solution that satisfies the positive kinetic energy coordinate condition. Finally, we discuss simply the case of the Tolman metric.
ABAREX -- A neutron spherical optical-statistical-model code -- A user`s manual
Smith, A.B. [ed.; Lawson, R.D.
1998-06-01T23:59:59.000Z
The contemporary version of the neutron spherical optical-statistical-model code ABAREX is summarized with the objective of providing detailed operational guidance for the user. The physical concepts involved are very briefly outlined. The code is described in some detail and a number of explicit examples are given. With this document one should very quickly become fluent with the use of ABAREX. While the code has operated on a number of computing systems, this version is specifically tailored for the VAX/VMS work station and/or the IBM-compatible personal computer.
SPHERICALLY SYMMETRIC NLTE MODEL ATMOSPHERES OF HOT HYDROGEN-HELIUM FIRST STARS
Kubat, Jiri [Astronomicky ustav, Akademie ved Ceske Republiky, CZ-251 65 Ondrejov (Czech Republic)
2012-12-15T23:59:59.000Z
We present results of our calculations of NLTE model stellar atmospheres for hot Population III stars composed of hydrogen and helium. We use our own computer code for the calculation of spherically symmetric NLTE model atmospheres in hydrostatic and radiative equilibrium. The model atmospheres are then used for the calculation of emergent fluxes. These fluxes serve to evaluate the flow of high-energy photons for energies higher than ionization energies of hydrogen and helium, the so-called ionizing photon fluxes. We also present the time evolution of the ionizing photon fluxes.
NSTX-U Digital Coil Protection System Software Detailed Design
none,
2014-06-01T23:59:59.000Z
The National Spherical Torus Experiment (NSTX) currently uses a collection of analog signal processing solutions for coil protection. Part of the NSTX Upgrade (NSTX-U) entails replacing these analog systems with a software solution running on a conventional computing platform. The new Digital Coil Protection System (DCPS) will replace the old systems entirely, while also providing an extensible framework that allows adding new functionality as desired.
The NSTX Central Instrumentation and Control System
G. Oliaro; J. Dong; K. Tindall; P. Sichta
1999-12-17T23:59:59.000Z
Earlier this year the National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory achieved ''first plasma''. The Central Instrumentation and Control System was used to support plasma operations. Major elements of the system include the Process Control System, Plasma Control System, Network System, Data Acquisition System, and Synchronization System. This paper will focus on the Process Control System. Topics include the architecture, hardware interface, operator interface, data management, and system performance.
Conceptual design for the NSTX Central Instrumentation and Control System
Bashore, D.; Oliaro, G. Roney, P.; Sichta, P.; Tindall, K.
1997-09-01T23:59:59.000Z
The design and construction phase for the National Spherical Torus Experiment (NSTX) is under way at the Princeton Plasma Physics Laboratory (PPPL). Operation is scheduled to begin on April 30, 1999. This paper describes the conceptual design for the NSTX Central Instrumentation and Control (I and C) System. Major elements of the Central I and C System include the Process Control System, Plasma Control System, Network System, Data Acquisition System, and Synchronization System to support the NSTX experimental device.
(NSTX) D.A. Gates, R. Maingi, J. Menard, S. Kaye, S.A. Sabbagh, G. Taylor, J.R. Wilson, et al. November2 , G. Taylor1 , J.R. Wilson1 , M.G. Bell1 , R.E. Bell1 , S. Bernabei1 , J. Bialek2 , T. Biewer1 , W in the National Spherical Torus Experiment (NSTX) D. A. Gates1 , R. Maingi4 , J. Menard1 , S. Kaye1 , S.A. Sabbagh
Broader source: Energy.gov [DOE]
The U.S. Department of Energy (DOE) is participating in a National Tribal Energy Summit September 23–25, 2015, in Washington, D.C. The National Summit supports the Obama Administration’s ongoing commitment to assist tribal efforts to enhance energy security, increase community resiliency, and cultivate a sustainable energy future.
The National Cancer Institute,
The National Cancer Institute, International Cancer Information Center Bldg. 82, Rm 123 Bethesda, MD 20892 The National Cancer Institute (NCI) is part of the Federal Government. NCI coordinates the government's cancer research program. It is the largest of the 17 biomedical research institutes and centers
National Institutes of Health National Institute of Mental Health
Baker, Chris I.
National Institutes of Health National Institute of Mental Health Department of Health and HumanNational Institute of Mental Health Division of Intramural Research Programs http://intramural.nimh.nih.gov/ [NIMH of Fellowship Training] National Institutes of Health National Institute of Mental Health Department of Health
New model of calculating the energy transfer efficiency for the spherical theta-pinch device
Xu, G; Loisch, G; Xiao, G; Jacoby, J; Weyrich, K; Li, Y; Zhao, Y
2015-01-01T23:59:59.000Z
Ion-beam-plasma-interaction plays an important role in the field of Warm Dense Matter (WDM) and Inertial Confinement Fusion (ICF). A spherical theta pinch is proposed to act as a plasma target in various applications including a plasma stripper cell. One key parameter for such applications is the free electron density. A linear dependency of this density to the amount of energy transferred into the plasma from an energy storage was found by C. Teske. Since the amount of stored energy is known, the energy transfer efficiency is a reliable parameter for the design of a spherical theta pinch device. The traditional two models of energy transfer efficiency are based on assumptions which comprise the risk of systematical errors. To obtain precise results, this paper proposes a new model without the necessity of any assumption to calculate the energy transfer efficiency for an inductively coupled plasma device. Further, a comparison of these three different models is given at a fixed operation voltage for the full ...
Non-perturbative corrections to mean-field behavior: spherical model on spider-web graph
Ajit C. Balram; Deepak Dhar
2012-02-09T23:59:59.000Z
We consider the spherical model on a spider-web graph. This graph is effectively infinite-dimensional, similar to the Bethe lattice, but has loops. We show that these lead to non-trivial corrections to the simple mean-field behavior. We first determine all normal modes of the coupled springs problem on this graph, using its large symmetry group. In the thermodynamic limit, the spectrum is a set of $\\delta$-functions, and all the modes are localized. The fractional number of modes with frequency less than $\\omega$ varies as $\\exp (-C/\\omega)$ for $\\omega$ tending to zero, where $C$ is a constant. For an unbiased random walk on the vertices of this graph, this implies that the probability of return to the origin at time $t$ varies as $\\exp(- C' t^{1/3})$, for large $t$, where $C'$ is a constant. For the spherical model, we show that while the critical exponents take the values expected from the mean-field theory, the free-energy per site at temperature $T$, near and above the critical temperature $T_c$, also has an essential singularity of the type $\\exp[ -K {(T - T_c)}^{-1/2}]$.
Abbas, Sayeed; Lodge, Timothy P. (UMM)
2008-12-09T23:59:59.000Z
Three distinct poly(styrene-b-isoprene) (SI) diblock copolymers with molecular weights of 16-16, 38-14, and 50-13 kDa for styrene and isoprene, respectively, formed spherical micelles when dissolved in diethyl phthalate (DEP). Since DEP is a styrene-selective solvent, micelles with polyisoprene in the core and polystyrene in the corona were formed. At block copolymer concentrations of 20%, 16%, and 14% in DEP, the spherical micelles of SI(16-16), SI(38-14), and SI(50-13) pack onto a face-centered cubic (FCC) lattice, a mixture of FCC and body-centered cubic (BCC) lattices, and a BCC lattice, respectively. Polystyrene homopolymers with molecular weights of 4, 48, and 180 kDa were added to these ordered solutions. The following general trends were observed: the FCC phase tended to disorder, and samples that originally behaved like soft solids exhibited liquidlike flow behavior. The effect increased strongly with both the molecular weight and concentration of homopolymer in the solution. Furthermore, the BCC lattice tended to be displaced by the FCC lattice, or to disorder, when homopolymer was added. These results can be explained by invoking depletion interactions, which have been studied extensively in colloid/polymer mixtures. However, the phenomenon differs in certain details from colloidal systems because the addition of homopolymer can also influence the aggregation number of the micelles, which in turn affects the lattice packing of the micelles.
Hossein Ghaffarnejad
2015-04-29T23:59:59.000Z
Aim of the paper is to obtain 2d analogue of the backreaction equation which will be useful to study final state of quantum perturbed spherically symmetric curved space times. Thus we take Einstein-massless-scalar $\\psi$ tensor gravity model described on class of spherically symmetric curved space times. We rewrite the action functional in 2d analogue in terms of dimensionless dilaton-matter field $(\\chi=\\Phi\\psi)$ where dilaton field $\\Phi$ is conformal factor of 2-sphere. Then we seek renormalized expectation value of quantum dilaton-matter field stress tensor operator by applying Hadamard rennormalization prescription. Singularity of the Green function is assumed to be has logarithmic form. Covariantly conservation condition on the renormalized quantum dilaton-matter stress tensor demands to input a variable cosmological parameter $\\lambda(x)$. Energy conditions (weak, strong and null) is studied on the obtained renormalized stress tensor leading to dynamical equations for $\\lambda(x), \\Phi$ and quantum vacuum state $W_0(x)=_{ren}.$ In weak quantum field limits our obtained trace anomaly corresponds to one which obtained from zeta function regularization method. Setting null-like apparent horizon equation $\
Nonlinear effects in the extraction of laminar flame speeds from expanding spherical flames
Kelley, A.P.; Law, C.K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)
2009-09-15T23:59:59.000Z
Various factors affecting the determination of laminar flames speeds from outwardly propagating spherical flames in a constant-pressure combustion chamber were considered, with emphasis on the nonlinear variation of the stretched flame speed to the flame stretch rate, and the associated need to nonlinearly extrapolate the stretched flame speed to yield an accurate determination of the laminar flame speed and Markstein length. Experiments were conducted for lean and rich n-butane/air flames at 1atm initial pressure, demonstrating the complex and nonlinear nature of the dynamics of flame evolution, and the strong influences of the ignition transient and chamber confinement during the initial and final periods of the flame propagation, respectively. These experimental data were analyzed using the nonlinear relation between the stretched flame speed and stretch rate, yielding laminar flame speeds that agree well with data determined from alternate flame configurations. It is further suggested that the fidelity in the extraction of the laminar flame speed from expanding spherical flames can be facilitated by using small ignition energy and a large combustion chamber. (author)
Dzhunushaliev, Vladimir [Institute for Basic Research, Eurasian National University, Astana, 010008 (Kazakhstan); Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic, 265 a, Chui Street, Bishkek, 720071 (Kyrgyzstan); Institut fuer Physik, Universitaet Oldenburg, Postfach 2503 D-26111 Oldenburg (Germany); Folomeev, Vladimir [Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic, 265 a, Chui Street, Bishkek, 720071 (Kyrgyzstan); Institut fuer Physik, Universitaet Oldenburg, Postfach 2503 D-26111 Oldenburg (Germany); Singleton, Douglas [Physics Department, CSU Fresno, Fresno, California 93740-8031 (United States); Myrzakulov, Ratbay [Eurasian International Center for Theoretical Physics and Department of General and Theoretical Physics, Eurasian National University, Astana, 010008 (Kazakhstan)
2010-08-15T23:59:59.000Z
In this paper we investigate wormhole and spherically symmetric solutions in four-dimensional gravity plus a matter source consisting of a ghost scalar field with a sine-Gordon potential. For the wormhole solutions we also include the possibility of electric and/or magnetic charges. For both types of solutions we perform a linear stability analysis and show that the wormhole solutions are stable and that when one turns on the electric and/or magnetic field the solution remains stable. The linear stability analysis of the spherically symmetric solutions indicates that they can be stable or unstable depending on one of the parameters of the system. This result for the spherically symmetric solution is nontrivial since a previous investigation of four-dimensional gravity plus a ghost scalar field with a {lambda}{phi}{sup 4} interaction found only unstable spherically symmetric solutions. Both the wormhole and spherically symmetric solutions presented here asymptotically go to anti-de Sitter space-time.
Hu, Michael Z.
2006-05-23T23:59:59.000Z
Disclosed is a method for making amorphous spherical particles of zirconium titanate and crystalline spherical particles of zirconium titanate comprising the steps of mixing an aqueous solution of zirconium salt and an aqueous solution of titanium salt into a mixed solution having equal moles of zirconium and titanium and having a total salt concentration in the range from 0.01 M to about 0.5 M. A stearic dispersant and an organic solvent is added to the mixed salt solution, subjecting the zirconium salt and the titanium salt in the mixed solution to a coprecipitation reaction forming a solution containing amorphous spherical particles of zirconium titanate wherein the volume ratio of the organic solvent to aqueous part is in the range from 1 to 5. The solution of amorphous spherical particles is incubated in an oven at a temperature .ltoreq.100.degree. C. for a period of time .ltoreq.24 hours converting the amorphous particles to fine or ultrafine crystalline spherical particles of zirconium titanate.
National Laboratory's Weapons Program
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 Annual Report ErnestNationalNationalNationalMcMillan
Sandia National Laboratories: National Solar Thermal Test Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Energy, Solar, Solar Newsletter A team from Sandia National Laboratories' (SNL) National Solar Thermal Test Facility (NSTTF) recently won a first place Excellence Award in the...
Drell receives National Medal of Science | National Nuclear Security...
National Nuclear Security Administration (NNSA)
Drell receives National Medal of Science | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...
Sandia National Laboratories: National Solar Thermal Test Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Solar Thermal Test Facility SolarReserve Is Testing Prototype Heliostats at NSTTF On March 3, 2015, in Concentrating Solar Power, Energy, Facilities, National Solar...
Laser induced thermal-wave fields in multi-layered spherical solids based on Green function method
Zhang Jie; Wang Chinhua [Key Lab of Modern Optical Technologies of Jiangsu Province, Institute of Modern Optical Technologies, Soochow University, Suzhou, Jiangsu 215006 (China); Xie Guangxi [Key Lab of Modern Optical Technologies of Jiangsu Province, Institute of Modern Optical Technologies, Soochow University, Suzhou, Jiangsu 215006 (China); Department of Physics, Jiangnan University, Wuxi, Jiangsu 214122 (China); Mandelis, Andreas [Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, M5S 3G8 Ontario (Canada)
2012-08-01T23:59:59.000Z
In this paper, we establish a Green-function based theoretical model for evaluating solid multi-layered spherical samples which are illuminated by a frequency modulated incident beam. The specific Green function for the multi-layered spherical structure is derived and an analytical expression for the thermal-wave field in such a spherical sample is presented. The characteristics of the thermal-wave field with respect to the thermophysical, geometrical, and measurement parameters are presented. Unlike the quadruple method, the Green function method is capable of evaluating thermal-wave fields at any point of multi-layered structures with arbitrary intensity distributions of incident laser beams. Furthermore, experimental validation is also presented in the form of experimental results with steel spheres of various diameters.
Broader source: Energy.gov [DOE]
HISTORYThe Argonne National Laboratory (ANL) site is approximately 27 miles southwest of downtown Chicago in DuPage County, Illinois. The 1,500 acre ANL site is completely surrounded by the 2,240...
Los Alamos National Laboratory's
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
takes part in Blue Star Museums program May 16, 2012 Free admission for active duty military, their family members LOS ALAMOS, New Mexico, May 16, 2012-Los Alamos National...
National Energy Codes Conference
Broader source: Energy.gov [DOE]
Join us in Nashville, TN March 23-26, 2015 for the National Energy Codes Conference! Additional details, including registration information, a preliminary agenda, the application for the Jeffrey A...
Sandia National Laboratories Problem
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Sandia National Laboratories Problem The electric grid relies on transmission of power from the production source - be it a coal-fired plant, solar array, or wind farm - to the...
Office of Energy Efficiency and Renewable Energy (EERE)
The AISES National Conference is a one-of-a-kind, three day event convening graduate, undergraduate, and high school junior and senior students, teachers, workforce professionals, corporate and...
Broader source: Energy.gov [DOE]
Bioenergy, the use of agricultural waste and forestry byproducts to generate heat and energy, will be celebrated during the second annual National Bioenergy Day on October 22, 2014. This is an...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Hazardous devices teams showcase skills at Robot Rodeo June 24-27 June 18, 2014 Bomb squads compete in timed scenarios at Los Alamos National Laboratory LOS ALAMOS, N.M., June 19,...
Brookhaven National Laboratory
Broader source: Energy.gov [DOE]
Site OverviewThe Brookhaven National Laboratory (BNL) was established in 1947 by the Atomic Energy Commission (AEC) (predecessor to U.S. Department of Energy [DOE]). Formerly Camp Upton, a U.S....
National Synchrotron Light Source
None
2010-01-08T23:59:59.000Z
A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Germany, and Sandia National Laboratories focus high-intensity light on an ultra-thin plastic sheet infused with an isotope of hydrogen called deuterium. - 2 - The laser light -...
Biomass Feedstock National User Facility
Broader source: Energy.gov [DOE]
Breakout Session 1B—Integration of Supply Chains I: Breaking Down Barriers Biomass Feedstock National User Facility Kevin L. Kenney, Director, Biomass Feedstock National User Facility, Idaho National Laboratory
Climate Change and National Security
Alyson, Fleming; Summer, Kelly; Summer, Martin; Lauren, Franck; Jonathan, Mark
2015-01-01T23:59:59.000Z
CLIMATE CHANGE Multiplying Threats to National Securityfor the impacts of climate change on national security. Pagea warming world. Page 11 “Climate change acts as a threat
Intelligence team given national honor
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Intelligence team given national honor Intelligence team given national honor A team known as the LANL Field Intelligence Element is being honored with the Department of Energy...
Sandia National Laboratories: Solar Newsletter
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Energy, Solar, Solar Newsletter A team from Sandia National Laboratories' (SNL) National Solar Thermal Test Facility (NSTTF) recently won a first place Excellence Award in the...
Mark Peters | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Laboratory, where he managed the science and engineering testing program at the Yucca Mountain Project. Before joining Los Alamos National Laboratory, Dr. Peters was a...
Ringler, Todd D [Los Alamos National Laboratory; Gunzburger, Max [FLORIDA STATE UNIV; Ju, Lili [UNIV OF SOUTH CAROLINA
2008-01-01T23:59:59.000Z
During the next decade and beyond, climate system models will be challenged to resolve scales and processes that are far beyond their current scope. Each climate system component has its prototypical example of an unresolved process that may strongly influence the global climate system, ranging from eddy activity within ocean models, to ice streams within ice sheet models, to surface hydrological processes within land system models, to cloud processes within atmosphere models. These new demands will almost certainly result in the develop of multi-resolution schemes that are able, at least regional to faithfully simulate these fine-scale processes. Spherical Centroidal Voronoi Tessellations (SCVTs) offer one potential path toward the development of robust, multi-resolution climate system component models, SCVTs allow for the generation of high quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function, each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean-ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear shallow-water equations spanning the entire surface of the sphere. This example is used to elucidate both the potential benefits of this multi-resolution method and the challenges ahead.
National Ignition Facility | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex andFOURPhoto of powerContactsAdministration9 National9Record2015 |
National System Templates: Building Sustainable National Inventory
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP a g eWorks -09-0018-CX JumpShunMontpelier,Nantong BIOLUX BioenergyNational Park ServiceSolarManagement
Sandia National Laboratories | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefinersUpcoming Release of the University ofTwo SandiansNationalSAND NO.
Sandia National Laboratories | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefinersUpcoming Release of the University ofTwo SandiansNationalSAND NO.Allison
Sandia National Laboratories | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefinersUpcoming Release of the University ofTwo SandiansNationalSAND NO.AllisonKevin
Sandia National Laboratories | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefinersUpcoming Release of the University ofTwo SandiansNationalSAND
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014 AlsoLos
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014DARHT: A
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014DARHT:
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014DARHT:A
National Security Science | Los National Alamos Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gifSolarApril4 AnnualperformanceNationalSecurityJuly 2014DARHT:AHow
National Nuclear Security Administration Los Alamos National
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020, 029, 0049,NASA |andManagement20National Nuclear
National Nuclear Security Administration | National Nuclear Security
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020, 029, 0049,NASA |andManagement20NationalDepartment
sandia national lab | National Nuclear Security Administration
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020,holiday | National Nuclear39omeganational lab |