Evaluation of the Revolver Ignition Design at the National Ignition Facility Using Polar-Direct-Drive Illumination

Science.gov (United States)

McKenty, P. W.; Collins, T. J. B.; Marozas, J. A.; Campbell, E. M.; Molvig, K.; Schmitt, M.

2017-10-01

The direct-drive ignition design Revolver employs a triple-shell target using a beryllium ablator, a copper driver, and an eventual gold pusher. Symmetric numerical calculations indicate that each of the three shells exhibit low convergence ( 3to 5) resulting in a modest gain (G 4) for 1.7 MJ of incident laser energy. Studies are now underway to evaluate the robustness of this design employing polar direct drive (PDD) at the National Ignition Facility. Integral to these calculations is the leveraging of illumination conditioning afforded by research done to demonstrate ignition for a traditional PDD hot-spot target design. Two-dimensional simulation results, employing nonlocal electron-thermal transport and cross-beam energy transport, will be presented that indicate ignition using PDD. A study of the allowed levels of long-wavelength perturbations (target offset and power imbalance) not precluding ignition will also be examined. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Ignition and burn propagation with suprathermal electron auxiliary heating

International Nuclear Information System (INIS)

Han Shensheng; Wu Yanqing

2000-01-01

The rapid development in ultrahigh-intensity lasers has allowed the exploration of applying an auxiliary heating technique in inertial confinement fusion (ICF) research. It is hoped that, compared with the 'standard fast ignition' scheme, raising the temperature of a hot-spot over the ignition threshold based on the shock-heated temperature will greatly reduce the required output energy of an ignition ultrahigh-intensity pulse. One of the key issues in ICF auxiliary heating is: how can we transport the exogenous energy efficiently into the hot-spot of compressed DT fuel? A scheme is proposed with three phases. First, a partial-spherical-shell capsule, such as double-conical target, is imploded as in the conventional approach to inertial fusion to assemble a high-density fuel configuration with a hot-spot of temperature lower than the ignition threshold. Second, a hole is bored through the shell outside the hot-spot by suprathermal electron explosion boring. Finally, the fuel is ignited by suprathermal electrons produced in the high-intensity ignition laser-plasma interactions. Calculations with a simple hybrid model show that the new scheme can possibly lead to ignition and burn propagation with a total drive energy of a few tens of kilojoules and an output energy as low as hundreds of joules for a single ignition ultrahigh-intensity pulse. (author)

High-Gain Shock Ignition on the National Ignition Facility

Science.gov (United States)

Perkins, L. J.; Lafortune, K.; Bailey, D.; Lambert, M.; MacKinnon, A.; Blackfield, D.; Comley, A.; Schurtz, G.; Ribeyre, X.; Lebel, E.; Casner, A.; Craxton, R. S.; Betti, R.; McKenty, P.; Anderson, K.; Theobald, W.; Schmitt, A.; Atzeni, S.; Schiavi, A.

2010-11-01

Shock ignition offers the possibility for a near-term test of high-gain ICF on the NIF at less than 1MJ drive energy and with day-1 laser hardware. We will summarize the status of target performance simulations, delineate the critical issues and describe the R&D program to be performed in order to test the potential of a shock-ignited target on NIF. In shock ignition, compressed fuel is separately ignited by a late-time laser-driven shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, simulations indicate that fusion energy gains of 60 may be achievable at laser energies around 0.5MJ. Like fast ignition, shock ignition offers high gain but requires only a single laser with less demanding timing and focusing requirements. Conventional symmetry and stability constraints apply, thus a key immediate step towards attempting shock ignition on NIF is to demonstrate adequacy of low-mode uniformity and shock symmetry under polar drive

Double shell tanks emergency pumping plan

International Nuclear Information System (INIS)

Tangen, M.J.

1994-01-01

At the request of the Department of Energy (DOE), a formal plan for the emergency transfer of waste from a leaking double shell tank to a designated receiver tank has been developed. This plan is in response to the priority 2 safety issue ''Response to a leaking double-shell tank'' in the DOE Report to Congress, 1991. The plan includes the tanks in four of the east tank farms and one of the west farms. The background information and supporting calculations used for the creation of the emergency plan are discussed in this document. The scope of this document is all of the double shell tanks in the AN, AP, AW, AY, and SY farms. The transfer lines, flush pits, and valve pits involved in the transfer of waste between these farms are also included in the scope. Due to the storage of high heat waste, AZ farm is excluded at this time

Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like α-GeO2

International Nuclear Information System (INIS)

Dong, Juncai; Zhang, Xiaoli; Wu, Ziyu; Chen, Dongliang; Zhang, Qian; Wu, Ye; Wu, Xiang

2014-01-01

With the combination of a single crystal diamond anvil cell and a polycapillary half-lens, the local structural evolution around germanium in tetrahedrally networked quartz-like α-GeO 2 has been investigated using extended x-ray absorption fine structure spectroscopy of up to 14 GPa by multiple-scattering analysis method. While the first shell Ge–O bond distances show a slight contraction with increasing pressure, the third shell Ge–O bond distances are found to decrease dramatically. The sluggish lengthening of the first shell Ge–O bond distances, initiated by coordination increase from fourfold to sixfold, occurs in the 7–14 GPa range just when the third shell Ge–O bond distances fall in the region of the second shell Ge–Ge bond distances. Moreover, these features are accompanied by the closing of intertetrahedral Ge–O–Ge angles and the opening of two intratetrahedral O–Ge–O angles, whose topological configuration surprisingly exhibits a helical chirality along the c axis that is opposite to the double helices of the corner-linked GeO 4 tetrahedra. These results suggest that the high-pressure phase transitions in quartz and quartz-like materials could be associated with a structural instability that is driven by the drastic collapse of the next-nearest-neighbour anion shell, which is consistent with the emergence of high-symmetry anion sublattice. Our findings provide crucial insights into the densification mechanisms of quartz-like oxides, which would have broad implications for our understanding of the metastability of various post-quartz crystalline phases and pressure-induced amorphization. (paper)

Variable convergence liquid layer implosions on the National Ignition Facility

Science.gov (United States)

Zylstra, A. B.; Yi, S. A.; Haines, B. M.; Olson, R. E.; Leeper, R. J.; Braun, T.; Biener, J.; Kline, J. L.; Batha, S. H.; Berzak Hopkins, L.; Bhandarkar, S.; Bradley, P. A.; Crippen, J.; Farrell, M.; Fittinghoff, D.; Herrmann, H. W.; Huang, H.; Khan, S.; Kong, C.; Kozioziemski, B. J.; Kyrala, G. A.; Ma, T.; Meezan, N. B.; Merrill, F.; Nikroo, A.; Peterson, R. R.; Rice, N.; Sater, J. D.; Shah, R. C.; Stadermann, M.; Volegov, P.; Walters, C.; Wilson, D. C.

2018-05-01

Liquid layer implosions using the "wetted foam" technique, where the liquid fuel is wicked into a supporting foam, have been recently conducted on the National Ignition Facility for the first time [Olson et al., Phys. Rev. Lett. 117, 245001 (2016)]. We report on a series of wetted foam implosions where the convergence ratio was varied between 12 and 20. Reduced nuclear performance is observed as convergence ratio increases. 2-D radiation-hydrodynamics simulations accurately capture the performance at convergence ratios (CR) ˜ 12, but we observe a significant discrepancy at CR ˜ 20. This may be due to suppressed hot-spot formation or an anomalous energy loss mechanism.

Fast ignition upon the implosion of a thin shell onto a precompressed deuterium-tritium ball

Science.gov (United States)

Gus'kov, S. Yu.; Zmitrenko, N. V.

2012-11-01

Fast ignition of a precompressed inertial confinement fusion (ICF) target by a hydrodynamic material flux is investigated. A model system of hydrodynamic objects consisting of a central deuterium-tritium (DT) ball and a concentric two-layer shell separated by a vacuum gap is analyzed. The outer layer of the shell is an ablator, while the inner layer consists of DT ice. The igniting hydrodynamic flux forms as a result of laser-driven acceleration and compression of the shell toward the system center. A series of one-dimensional numerical simulations of the shell implosion, the collision of the shell with the DT ball, and the generation and propagation of thermonuclear burn waves in both parts of the system are performed. Analytic models are developed that describe the implosion of a thin shell onto a central homogeneous ball of arbitrary radius and density and the initiation and propagation of a thermonuclear burn wave induced by such an implosion. Application of the solution of a model problem to analyzing the implosion of a segment of a spherical shell in a conical channel indicates the possibility of fast ignition of a spherical ICF target from a conical target driven by a laser pulse with an energy of 500-700 kJ.

Hi shells, supershells, shell-like objects, and ''worms''

International Nuclear Information System (INIS)

Heiles, C.

1984-01-01

We present photographic representations of the combination of two Hi surveys, so as to eliminate the survey boundaries at Vertical BarbVertical Bar = 10 0 . We also present high-contrast photographs for particular velocities to exhibit weak Hi features. All of these photographs were used to prepare a new list of Hi shells, supershells, and shell-like objects. We discuss the structure of three shell-like objects that are associated with high-velocity gas, and with gas at all velocities that is associated with radio continuum loops I, II, and III. We use spatial filtering to find wiggly gas filaments: ''worms'': crawling away from the galactic plane in the inner Galaxy. The ''worms'' are probably parts of shells that are open at the top; such shells should be good sources of hot gas for the galactic halo

Physics of laser-plasma interaction for shock ignition of fusion reactions

International Nuclear Information System (INIS)

Tikhonchuk, V T; Colaïtis, A; Vallet, A; Llor Aisa, E; Duchateau, G; Nicolaï, Ph; Ribeyre, X

2016-01-01

The shock ignition scheme is an alternative approach, which aims to achieve ignition of fusion reactions in two subsequent steps: first, the target is compressed at a low implosion velocity and second, a strong converging shock is launched during the stagnation phase and ignites the hot spot. In this paper we describe the major elements of this scheme and recent achievements concerning the laser-plasma interaction, the crucial role of hot electrons in the shock generation, the shock amplification in the imploding shell and the ignition conditions. (paper)

Definition of Ignition in Inertial Confinement Fusion

Science.gov (United States)

Christopherson, A. R.; Betti, R.

2017-10-01

Defining ignition in inertial confinement fusion (ICF) is an unresolved problem. In ICF, a distinction must be made between the ignition of the hot spot and the propagation of the burn wave in the surrounding dense fuel. Burn propagation requires that the hot spot is robustly ignited and the dense shell exhibits enough areal density. Since most of the energy gain comes from burning the dense shell, in a scale of increasing yields, hot-spot ignition comes before high gains. Identifying this transition from hot-spot ignition to burn-wave propagation is key to defining ignition in general terms applicable to all fusion approaches that use solid DT fuel. Ad hoc definitions such as gain = 1 or doubling the temperature are not generally valid. In this work, we show that it is possible to identify the onset of ignition through a unique value of the yield amplification defined as the ratio of the fusion yield including alpha-particle deposition to the fusion yield without alphas. Since the yield amplification is a function of the fractional alpha energy fα =EαEα 2Ehs 2Ehs (a measurable quantity), it appears possible not only to define ignition but also to measure the onset of ignition by the experimental inference of the fractional alpha energy and yield amplification. This material is based upon work supported by the Department of Energy Office of Fusion Energy Services under Award Number DE-FC02-04ER54789 and National Nuclear Security Administration under Award Number DE-NA0001944.

On statistical acceleration convergence of double sequences

Directory of Open Access Journals (Sweden)

Bipan Hazarika

2017-04-01

Full Text Available In this article the notion of statistical acceleration convergence of double sequences in Pringsheim's sense has been introduced. We prove the decompostion theorems for  statistical acceleration convergence of double sequences and some theorems related to that concept have been established using the four dimensional matrix transformations. We provided some examples, where the results of acceleration convergence fails to hold for the statistical cases.

Hanford double shell tank corrosion monitoring instrument tree prototype

International Nuclear Information System (INIS)

Nelson, J.L.; Edgemon, G.L.; Ohl, P.C.

1995-11-01

High-level nuclear wastes at the Hanford site are stored underground in carbon steel double-shell and single-shell tanks (DSTs and SSTs). The installation of a prototype corrosion monitoring instrument tree into DST 241-A-101 was completed in December 1995. The instrument tree has the ability to detect and discriminate between uniform corrosion, pitting, and stress corrosion cracking (SCC) through the use of electrochemical noise measurements and a unique stressed element, three-electrode probe. The tree itself is constructed of AISI 304L stainless steel (UNS S30403), with probes in the vapor space, vapor/liquid interface and liquid. Successful development of these trees will allow their application to single shell tanks and the transfer of technology to other US Department of Energy (DOE) sites. Keywords: Hanford, radioactive waste, high-level waste tanks, electrochemical noise, probes, double-shell tanks, single-shell tanks, corrosion

Depth and Extent of Gas-Ablator Mix in Symcap Implosions at the National Ignition Facility

Science.gov (United States)

Pino, Jesse; Ma, T.; MacLaren, S. A.; Salmonson, J. D.; Ho, D.; Khan, S. F.; Masse, L.; Ralph, J. E.; Czajka, C.; Casey, D.; Sacks, R.; Smalyuk, V. A.; Tipton, R. E.; Kyrala, G. A.

2017-10-01

A longstanding question in ICF physics has been the extent to which capsule ablator material mixes into the burning fusion fuel and degrades performance. Several recent campaigns at the National Ignition Facility have examined this question through the use of separated reactants. A layer of CD plastic is placed on the inner surface of the CH shell and the shell is filled with a gas mixture of H and T. This allows for simultaneous neutron signals that inform different aspects of the physics; we get core TT neutron yield, atomic mix from the DT neutrons, and information about shell heating from the DD neutron signal. By systematically recessing the CD layer away from the gas boundary we gain an inference of the depth of the mixing layer. This presentation will cover three campaigns to look at mixing depth: An ignition-like design (``Low-foot'') at two convergence ratios, as well as a robust, nearly one-dimensional, low convergence, symmetric platform designed to minimize ablation front feed-through (HED 2-shock). We show that the 2-shock capsule has less ablator-gas mix, and compare the experimental results to mix-model simulations. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344, LLNS, LLC.

Shell-like structures

CERN Document Server

Altenbach, Holm

2011-01-01

In this volume, scientists and researchers from industry discuss the new trends in simulation and computing shell-like structures. The focus is put on the following problems: new theories (based on two-dimensional field equations but describing non-classical effects), new constitutive equations (for materials like sandwiches, foams, etc. and which can be combined with the two-dimensional shell equations), complex structures (folded, branching and/or self intersecting shell structures, etc.) and shell-like structures on different scales (for example: nano-tubes) or very thin structures (similar

Bright x-ray stainless steel K-shell source development at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

May, M. J.; Fournier, K. B.; Colvin, J. D.; Barrios, M. A.; Dewald, E. L.; Moody, J.; Patterson, J. R.; Schneider, M.; Widmann, K. [Lawrence Livermore National Laboratory, P.O. Box 808 L170, Livermore, California 94551 (United States); Hohenberger, M.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2015-06-15

High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ∼460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.

Reducing the effects of X-ray pre-heat in double shell NIF capsules by over-coating the high Z shell

Science.gov (United States)

Wilson, Douglas; Milovich, J. L.; Daughton, W. S.; Loomis, E. N.; Sauppe, J. P.; Dodd, E. S.; Merritt, E. C.; Montgomery, D. S.; Renner, D. B.; Haines, B. M.; Cardenas, T.; Desjardins, T.; Palaniyappan, S.; Batha, S. H.

2017-10-01

Hohlraum generated X-rays will penetrate the ablator of a double shell capsule and be absorbed in the outer surface of the inner capsule. The ablative pressure this generates drives a shock into the central fuel, and a reflected shock that reaches the inner high-Z shell surface before the main shock even enters the fuel. With a beryllium over-coat preheat X-rays deposit just inside the beryllium/high z interface. The beryllium tamps the preheat expansion, eliminating ablation, and dramatically reducing pressure. The slow shock or pressure wave it generates is then overtaken by the main shock, avoiding an early shock in the fuel and increasing capsule yield.

Double-shell tank system dangerous waste permit application

International Nuclear Information System (INIS)

1991-06-01

This Double-Shell Tank System Dangerous Waste Permit Application should be read in conjunction with the 242-A Evaporator Dangerous Waste Permit Application and the Liquid Effluent Retention Facility Dangerous Waste Permit Application, also submitted on June 28, 1991. Information contained in the Double-Shell Tank System permit application is referenced in the other two permit applications. The Double-Shell Tank System stores and treats mixed waste received from a variety of sources on the Hanford Site. The 242-A Evaporator treats liquid mixed waste received from the double-shell tanks. The 242-A Evaporator returns a mixed-waste slurry to the double-shell tanks and generates the dilute mixed-waste stream stored in the Liquid Effluent Retention Facility. This report contains information on the following topics: Facility Description and General Provisions; Waste Characteristics; Process Information; Groundwater Monitoring; Procedures to Prevent Hazards; Contingency Plan; Personnel Training; Exposure Information Report; Waste Minimization Plan; Closure and Postclosure Requirements; Reporting and Recordkeeping; other Relevant Laws; and Certification. 150 refs., 141 figs., 118 tabs

Asymmetric-shell ignition capsule design to tune the low-mode asymmetry during the peak drive

International Nuclear Information System (INIS)

Gu, Jianfa; Dai, Zhensheng; Song, Peng; Zou, Shiyang; Ye, Wenhua; Zheng, Wudi; Gu, Peijun; Wang, Jianguo; Zhu, Shaoping

2016-01-01

The low-mode radiation flux asymmetry in the hohlraum is a main source of performance degradation in the National Ignition Facility (NIF) implosion experiments. To counteract the deleterious effects of the large positive P2 flux asymmetry during the peak drive, this paper develops a new tuning method called asymmetric-shell ignition capsule design which adopts the intentionally asymmetric CH ablator layer or deuterium-tritium (DT) ice layer. A series of two-dimensional implosion simulations have been performed, and the results show that the intentionally asymmetric DT ice layer can significantly improve the fuel ρR symmetry, hot spot shape, hot spot internal energy, and the final neutron yield compared to the spherical capsule. This indicates that the DT asymmetric-shell capsule design is an effective tuning method, while the CH ablator asymmetric-shell capsule could not correct the fuel ρR asymmetry, and it is not as effective as the DT asymmetric-shell capsule design.

Asymmetric-shell ignition capsule design to tune the low-mode asymmetry during the peak drive

Science.gov (United States)

Gu, Jianfa; Dai, Zhensheng; Song, Peng; Zou, Shiyang; Ye, Wenhua; Zheng, Wudi; Gu, Peijun; Wang, Jianguo; Zhu, Shaoping

2016-08-01

The low-mode radiation flux asymmetry in the hohlraum is a main source of performance degradation in the National Ignition Facility (NIF) implosion experiments. To counteract the deleterious effects of the large positive P2 flux asymmetry during the peak drive, this paper develops a new tuning method called asymmetric-shell ignition capsule design which adopts the intentionally asymmetric CH ablator layer or deuterium-tritium (DT) ice layer. A series of two-dimensional implosion simulations have been performed, and the results show that the intentionally asymmetric DT ice layer can significantly improve the fuel ρR symmetry, hot spot shape, hot spot internal energy, and the final neutron yield compared to the spherical capsule. This indicates that the DT asymmetric-shell capsule design is an effective tuning method, while the CH ablator asymmetric-shell capsule could not correct the fuel ρR asymmetry, and it is not as effective as the DT asymmetric-shell capsule design.

Asymmetric-shell ignition capsule design to tune the low-mode asymmetry during the peak drive

Energy Technology Data Exchange (ETDEWEB)

Gu, Jianfa, E-mail: gu-jianfa@iapcm.ac.cn; Dai, Zhensheng, E-mail: dai-zhensheng@iapcm.ac.cn; Song, Peng; Zou, Shiyang; Ye, Wenhua; Zheng, Wudi; Gu, Peijun; Wang, Jianguo; Zhu, Shaoping [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

2016-08-15

The low-mode radiation flux asymmetry in the hohlraum is a main source of performance degradation in the National Ignition Facility (NIF) implosion experiments. To counteract the deleterious effects of the large positive P2 flux asymmetry during the peak drive, this paper develops a new tuning method called asymmetric-shell ignition capsule design which adopts the intentionally asymmetric CH ablator layer or deuterium-tritium (DT) ice layer. A series of two-dimensional implosion simulations have been performed, and the results show that the intentionally asymmetric DT ice layer can significantly improve the fuel ρR symmetry, hot spot shape, hot spot internal energy, and the final neutron yield compared to the spherical capsule. This indicates that the DT asymmetric-shell capsule design is an effective tuning method, while the CH ablator asymmetric-shell capsule could not correct the fuel ρR asymmetry, and it is not as effective as the DT asymmetric-shell capsule design.

Double shell tank waste analysis plan

International Nuclear Information System (INIS)

Mulkey, C.H.; Jones, J.M.

1994-01-01

Waste analysis plan for the double shell tanks. SD-WM-EV-053 is Superseding SD-WM-EV-057.This document provides the plan for obtaining information needed for the safe waste handling and storage of waste in the Double Shell Tank Systems. In Particular it addresses analysis necessary to manage waste according to Washington Administrative Code 173-303 and Title 40, parts 264 and 265 of the Code of Federal Regulations

Industrial mixing techniques for Hanford double-shell tanks

International Nuclear Information System (INIS)

Daymo, E.A.

1997-09-01

Jet mixer pumps are currently the baseline technology for sludge mobilization and mixing in one-million gallon double-shell tanks at the Hanford and Savannah River Sites. Improvements to the baseline jet mixer pump technology are sought because jet mixer pumps have moving parts that may fail or require maintenance. Moreover, jet mixers are relatively expensive, they heat the waste, and, in some cases, may not mobilize enough of the sludge. This report documents a thorough literature search for commercially available applicable mixing technologies that could be used for double-shell tank sludge mobilization and mixing. Textbooks, research articles, conference proceedings, mixing experts, and the Thomas Register were consulted to identify applicable technologies. While there are many commercial methods that could be used to mobilize sludge or mix the contents of a one-million gallon tank, few will work given the geometrical constraints (e.g., the mixer must fit through a 1.07-m-diameter riser) or the tank waste properties (e.g., the sludge has such a high yield stress that it generally does not flow under its own weight). Pulsed fluid jets and submersible Flygt mixers have already been identified at Hanford and Savannah River Sites for double-shell tank mixing applications. While these mixing technologies may not be applicable for double-shell tanks that have a thick sludge layer at the bottom (since too many of these mixers would need to be installed to mobilize most of the sludge), they may have applications in tanks that do not have a settled solids layer. Retrieval projects at Hanford and other U.S. Department of Energy sites are currently evaluating the effectiveness of these mixing techniques for tank waste applications. The literature search did not reveal any previously unknown technologies that should be considered for sludge mobilization and mixing in one-million gallon double-shell tanks

Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis

Science.gov (United States)

Amendt, Peter; Shestakov, A. I.; Landen, O. L.; Bradley, D. K.; Pollaine, S. M.; Suter, L. J.; Turner, R. E.

2001-06-01

Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule.

Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis

International Nuclear Information System (INIS)

Amendt, Peter; Shestakov, A.I.; Landen, O.L.; Bradley, D.K.; Pollaine, S.M.; Suter, L.J.; Turner, R.E.

2001-01-01

Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule

Volume ignition of laser driven fusion pellets and double layer effects

International Nuclear Information System (INIS)

Cicchitelli, L.; Eliezer, S.; Goldsworthy, M.P.; Green, F.; Hora, H.; Ray, P.S.; Stening, R.J.; Szichman, H.

1988-01-01

The realization of an ideal volume compression of laser-irradiated fusion pellets opens the possibility for an alternative to spark ignition proposed for many years for inertial confinement fusion. A re-evaluation of the difficulties of the central spark ignition of laser driven pellets is given. The alternative volume compression theory, together with volume burn and volume ignition, have received less attention and are re-evaluated in view of the experimental verification generalized fusion gain formulas, and the variation of optimum temperatures derived at self-ignition. Reactor-level DT fusion with MJ-laser pulses and volume compression to 50 times the solid-state density are estimated. Dynamic electric fields and double layers at the surface and in the interior of plasmas result in new phenomena for the acceleration of thermal electrons to suprathermal electrons. Double layers also cause a surface tension which stabilizes against surface wave effects and Rayleigh-Taylor instabilities. (author)

Statistical convergence of double sequences in intuitionistic fuzzy normed spaces

International Nuclear Information System (INIS)

Mursaleen, M.; Mohiuddine, S.A.

2009-01-01

Recently, the concept of intuitionistic fuzzy normed spaces was introduced by Saadati and Park [Saadati R, Park JH. Chaos, Solitons and Fractals 2006;27:331-44]. Karakus et al. [Karakus S, Demirci K, Duman O. Chaos, Solitons and Fractals 2008;35:763-69] have quite recently studied the notion of statistical convergence for single sequences in intuitionistic fuzzy normed spaces. In this paper, we study the concept of statistically convergent and statistically Cauchy double sequences in intuitionistic fuzzy normed spaces. Furthermore, we construct an example of a double sequence to show that in IFNS statistical convergence does not imply convergence and our method of convergence even for double sequences is stronger than the usual convergence in intuitionistic fuzzy normed space.

Hydrodynamic instability growth and mix experiments at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Smalyuk, V. A.; Barrios, M.; Caggiano, J. A.; Casey, D. T.; Cerjan, C. J.; Clark, D. S.; Edwards, M. J.; Haan, S. W.; Hammel, B. A.; Hamza, A.; Hsing, W. W.; Hurricane, O.; Kroll, J.; Landen, O. L.; Lindl, J. D.; Ma, T.; McNaney, J. M.; Mintz, M.; Parham, T.; Peterson, J. L. [Lawrence Livermore National Laboratory, NIF Directorate, Livermore, California 94550 (United States); and others

2014-05-15

Hydrodynamic instability growth and its effects on implosion performance were studied at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. Implosion performance and mix have been measured at peak compression using plastic shells filled with tritium gas and containing embedded localized carbon-deuterium diagnostic layers in various locations in the ablator. Neutron yield and ion temperature of the deuterium-tritium fusion reactions were used as a measure of shell-gas mix, while neutron yield of the tritium-tritium fusion reaction was used as a measure of implosion performance. The results have indicated that the low-mode hydrodynamic instabilities due to surface roughness were the primary culprits for yield degradation, with atomic ablator-gas mix playing a secondary role. In addition, spherical shells with pre-imposed 2D modulations were used to measure instability growth in the acceleration phase of the implosions. The capsules were imploded using ignition-relevant laser pulses, and ablation-front modulation growth was measured using x-ray radiography for a shell convergence ratio of ∼2. The measured growth was in good agreement with that predicted, thus validating simulations for the fastest growing modulations with mode numbers up to 90 in the acceleration phase. Future experiments will be focused on measurements at higher convergence, higher-mode number modulations, and growth occurring during the deceleration phase.

Molecular single photon double K-shell ionization

International Nuclear Information System (INIS)

Penent, F.; Nakano, M.; Tashiro, M.; Grozdanov, T.P.; Žitnik, M.; Carniato, S.; Selles, P.; Andric, L.; Lablanquie, P.; Palaudoux, J.; Shigemasa, E.; Iwayama, H.; Hikosaka, Y.; Soejima, K.; Suzuki, I.H.; Kouchi, N.; Ito, K.

2014-01-01

We have studied single photon double K-shell ionization of small molecules (N 2 , CO, C 2 H 2n (n = 1–3), …) and the Auger decay of the resulting double core hole (DCH) molecular ions thanks to multi-electron coincidence spectroscopy using a magnetic bottle time-of-flight spectrometer. The relative cross-sections for single-site (K −2 ) and two-site (K −1 K −1 ) double K-shell ionization with respect to single K-shell (K −1 ) ionization have been measured that gives important information on the mechanisms of single photon double ionization. The spectroscopy of two-site (K −1 K −1 ) DCH states in the C 2 H 2n (n = 1–3) series shows important chemical shifts due to a strong dependence on the C-C bond length. In addition, the complete cascade Auger decay following single site (K −2 ) ionization has been obtained

Explicitly-correlated ring-coupled-cluster-doubles theory: Including exchange for computations on closed-shell systems

Energy Technology Data Exchange (ETDEWEB)

Hehn, Anna-Sophia; Holzer, Christof; Klopper, Wim, E-mail: klopper@kit.edu

2016-11-10

Highlights: • Ring-coupled-cluster-doubles approach now implemented with exchange terms. • Ring-coupled-cluster-doubles approach now implemented with F12 functions. • Szabo–Ostlund scheme (SO2) implemented for use in SAPT. • Fast convergence to the limit of a complete basis. • Implementation in the TURBOMOLE program system. - Abstract: Random-phase-approximation (RPA) methods have proven to be powerful tools in electronic-structure theory, being non-empirical, computationally efficient and broadly applicable to a variety of molecular systems including small-gap systems, transition-metal compounds and dispersion-dominated complexes. Applications are however hindered due to the slow basis-set convergence of the electron-correlation energy with the one-electron basis. As a remedy, we present approximate explicitly-correlated RPA approaches based on the ring-coupled-cluster-doubles formulation including exchange contributions. Test calculations demonstrate that the basis-set convergence of correlation energies is drastically accelerated through the explicitly-correlated approach, reaching 99% of the basis-set limit with triple-zeta basis sets. When implemented in close analogy to early work by Szabo and Ostlund [36], the new explicitly-correlated ring-coupled-cluster-doubles approach including exchange has the perspective to become a valuable tool in the framework of symmetry-adapted perturbation theory (SAPT) for the computation of dispersion energies of molecular complexes of weakly interacting closed-shell systems.

High-density and high-ρR fuel assembly for fast-ignition inertial confinement fusion

International Nuclear Information System (INIS)

Betti, R.; Zhou, C.

2005-01-01

Scaling relations to optimize implosion parameters for fast-ignition inertial confinement fusion are derived and used to design high-gain fast-ignition targets. A method to assemble thermonuclear fuel at high densities, high ρR, and with a small-size hot spot is presented. Massive cryogenic shells can be imploded with a low implosion velocity V I on a low adiabat α using the relaxation-pulse technique. While the low V I yields a small hot spot, the low α leads to large peak values of the density and areal density. It is shown that a 750 kJ laser can assemble fuel with V I ≅1.7x10 7 cm/s, α≅0.7, ρ≅400 g/cc, ρR≅3 g/cm 2 , and a hot-spot volume of less than 10% of the compressed core. If fully ignited, this fuel assembly can produce high gains of interest to inertial fusion energy applications

On the Fielding of a High Gain, Shock-Ignited Target on the National Ignitiion Facility in the Near Term

International Nuclear Information System (INIS)

Perkins, L.J.; Betti, R.; Schurtz, G.P.; Craxton, R.S.; Dunne, A.M.; LaFortune, K.N.; Schmitt, A.J.; McKenty, P.W.; Bailey, D.S.; Lambert, M.A.; Ribeyre, X.; Theobald, W.R.; Strozzi, D.J.; Harding, D.R.; Casner, A.; Atzemi, S.; Erbert, G.V.; Andersen, K.S.; Murakami, M.; Comley, A.J.; Cook, R.C.; Stephens, R.B.

2010-01-01

Shock ignition, a new concept for igniting thermonuclear fuel, offers the possibility for a near-term (∼3-4 years) test of high gain inertial confinement fusion on the National Ignition Facility at less than 1MJ drive energy and without the need for new laser hardware. In shock ignition, compressed fusion fuel is separately ignited by a strong spherically converging shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, fusion energy gains of ∼60 may be achievable on NIF at laser drive energies around ∼0.5MJ. Because of the simple all-DT target design, its in-flight robustness, the potential need for only 1D SSD beam smoothing, minimal early time LPI preheat, and use of present (indirect drive) laser hardware, this target may be easier to field on NIF than a conventional (polar) direct drive hotspot ignition target. Like fast ignition, shock ignition has the potential for high fusion yields at low drive energy, but requires only a single laser with less demanding timing and spatial focusing requirements. Of course, conventional symmetry and stability constraints still apply. In this paper we present initial target performance simulations, delineate the critical issues and describe the immediate-term R and D program that must be performed in order to test the potential of a high gain shock ignition target on NIF in the near term.

ICF ignition capsule neutron, gamma ray, and high energy x-ray images

Science.gov (United States)

Bradley, P. A.; Wilson, D. C.; Swenson, F. J.; Morgan, G. L.

2003-03-01

Post-processed total neutron, RIF neutron, gamma-ray, and x-ray images from 2D LASNEX calculations of burning ignition capsules are presented. The capsules have yields ranging from tens of kilojoules (failures) to over 16 MJ (ignition), and their implosion symmetry ranges from prolate (flattest at the hohlraum equator) to oblate (flattest towards the laser entrance hole). The simulated total neutron images emphasize regions of high DT density and temperature; the reaction-in-flight neutrons emphasize regions of high DT density; the gamma rays emphasize regions of high shell density; and the high energy x rays (>10 keV) emphasize regions of high temperature.

Indirectly driven, high convergence inertial confinement fusion implosions

International Nuclear Information System (INIS)

Cable, M.D.; Hatchett, S.P.; Caird, J.A.; Kilkenny, J.D.; Kornblum, H.N.; Lane, S.M.; Laumann, C.; Lerche, R.A.; Murphy, T.J.; Murray, J.; Nelson, M.B.; Phillion, D.W.; Powell, H.; Ress, D.B.

1994-01-01

A series of high convergence indirectly driven implosions has been done with the Nova Laser Fusion facility. These implosions were well characterized by a variety of measurements; computer models are in good agreement. The imploded fuel areal density was measured using a technique based on secondary neutron spectroscopy. At capsule convergences of 24:1, comparable to what is required for the hot spot of ignition scale capsules, these capsules achieved fuel densities of 19 g/cm 3 . Independent measurements of density, burn duration, and ion temperature gave nτθ=1.7±0.9x10 14 keV s/cm 3

Progress Toward Ignition on the National Ignition Facility

International Nuclear Information System (INIS)

Kauffman, R.L.

2011-01-01

The principal approach to ignition on the National Ignition Facility (NIF) is indirect drive. A schematic of an ignition target is shown in Figure 1. The laser beams are focused through laser entrance holes at each end of a high-Z cylindrical case, or hohlraum. The lasers irradiate the hohlraum walls producing x-rays that ablate and compress the fuel capsule in the center of the hohlraum. The hohlraum is made of Au, U, or other high-Z material. For ignition targets, the hohlraum is ∼0.5 cm diameter by ∼1 cm in length. The hohlraum absorbs the incident laser energy producing x-rays for symmetrically imploding the capsule. The fuel capsule is a ∼2-mm-diameter spherical shell of CH, Be, or C filled with DT fuel. The DT fuel is in the form of a cryogenic layer on the inside of the capsule. X-rays ablate the outside of the capsule, producing a spherical implosion. The imploding shell stagnates in the center, igniting the DT fuel. NIC has overseen installation of all of the hardware for performing ignition experiments, including commissioning of approximately 50 diagnostic systems in NIF. The diagnostics measure scattered optical light, x-rays from the hohlraum over the energy range from 100 eV to 500 keV, and x-rays, neutrons, and charged particles from the implosion. An example of a diagnostic is the Magnetic Recoil Spectrometer (MRS) built by a collaboration of scientists from MIT, UR-LLE, and LLNL shown in Figure 2. MRS measures the neutron spectrum from the implosion, providing information on the neutron yield and areal density that are metrics of the quality of the implosion. Experiments on NIF extend ICF research to unexplored regimes in target physics. NIF can produce more than 50 times the laser energy and more than 20 times the power of any previous ICF facility. Ignition scale hohlraum targets are three to four times larger than targets used at smaller facilities, and the ignition drive pulses are two to five times longer. The larger targets and longer

A polar-drive shock-ignition design for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2013-05-15

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

DOUBLE SHELL TANK INTEGRITY PROJECT HIGH LEVEL WASTE CHEMISTRY OPTIMIZATION

International Nuclear Information System (INIS)

WASHENFELDER DJ

2008-01-01

The U.S. Department of Energy's Office (DOE) of River Protection (ORP) has a continuing program for chemical optimization to better characterize corrosion behavior of High-Level Waste (HLW). The DOE controls the chemistry in its HLW to minimize the propensity of localized corrosion, such as pitting, and stress corrosion cracking (SCC) in nitrate-containing solutions. By improving the control of localized corrosion and SCC, the ORP can increase the life of the Double-Shell Tank (DST) carbon steel structural components and reduce overall mission costs. The carbon steel tanks at the Hanford Site are critical to the mission of safely managing stored HLW until it can be treated for disposal. The DOE has historically used additions of sodium hydroxide to retard corrosion processes in HLW tanks. This also increases the amount of waste to be treated. The reactions with carbon dioxide from the air and solid chemical species in the tank continually deplete the hydroxide ion concentration, which then requires continued additions. The DOE can reduce overall costs for caustic addition and treatment of waste, and more effectively utilize waste storage capacity by minimizing these chemical additions. Hydroxide addition is a means to control localized and stress corrosion cracking in carbon steel by providing a passive environment. The exact mechanism that causes nitrate to drive the corrosion process is not yet clear. The SCC is less of a concern in the newer stress relieved double shell tanks due to reduced residual stress. The optimization of waste chemistry will further reduce the propensity for SCC. The corrosion testing performed to optimize waste chemistry included cyclic potentiodynamic volarization studies. slow strain rate tests. and stress intensity factor/crack growth rate determinations. Laboratory experimental evidence suggests that nitrite is a highly effective:inhibitor for pitting and SCC in alkaline nitrate environments. Revision of the corrosion control

Thin shell, high velocity inertial confinement fusion implosions on the national ignition facility.

Science.gov (United States)

Ma, T; Hurricane, O A; Callahan, D A; Barrios, M A; Casey, D T; Dewald, E L; Dittrich, T R; Döppner, T; Haan, S W; Hinkel, D E; Berzak Hopkins, L F; Le Pape, S; MacPhee, A G; Pak, A; Park, H-S; Patel, P K; Remington, B A; Robey, H F; Salmonson, J D; Springer, P T; Tommasini, R; Benedetti, L R; Bionta, R; Bond, E; Bradley, D K; Caggiano, J; Celliers, P; Cerjan, C J; Church, J A; Dixit, S; Dylla-Spears, R; Edgell, D; Edwards, M J; Field, J; Fittinghoff, D N; Frenje, J A; Gatu Johnson, M; Grim, G; Guler, N; Hatarik, R; Herrmann, H W; Hsing, W W; Izumi, N; Jones, O S; Khan, S F; Kilkenny, J D; Knauer, J; Kohut, T; Kozioziemski, B; Kritcher, A; Kyrala, G; Landen, O L; MacGowan, B J; Mackinnon, A J; Meezan, N B; Merrill, F E; Moody, J D; Nagel, S R; Nikroo, A; Parham, T; Ralph, J E; Rosen, M D; Rygg, J R; Sater, J; Sayre, D; Schneider, M B; Shaughnessy, D; Spears, B K; Town, R P J; Volegov, P L; Wan, A; Widmann, K; Wilde, C H; Yeamans, C

2015-04-10

Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165  μm in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot implosions have demonstrated good performance, with higher velocity and better symmetry control at lower laser powers and energies than their nominal thickness ablator counterparts. Little to no hydrodynamic mix into the DT hot spot has been observed despite the higher velocities and reduced depth for possible instability feedthrough. Early results have shown good repeatability, with up to 1/2 the neutron yield coming from α-particle self-heating.

Performance requirements for the double-shell tank system: Phase 1

International Nuclear Information System (INIS)

Claghorn, R.D.

1998-01-01

This document establishes performance requirements for the double-shell tank system. These requirements, in turn, will be incorporated in the System Specification for the Double-Shell Tank System (Grenard and Claghorn 1998). This version of the document establishes requirements that are applicable to the first phase (Phase 1) of the Tank Waste Remediation System (TWRS) mission described in the TWRS Mission Analysis Report (Acree 1998). It does not specify requirements for either the Phase 2 mission or the double-shell tank system closure period

Self-ignition Properties of Peat, Palm Shell Fibre and Woods

Directory of Open Access Journals (Sweden)

Yulianto Sulistyo Nugroho

2010-10-01

Full Text Available Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures and the kinetic oxidation parameters are used to analyze the intrinsic properties of the samples to self-ignite. Thermal runaway reactions leading to ignition are indicated for all forest fuels tested. This reaction is affected by various factors including oven temperature, moisture content, chemical and physical properties as well as basket sizes. Attempt to extrapolate the results of these laboratoryscaled experiments for real fires still require further tests and assessments.

Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

Science.gov (United States)

Stefan, V. Alexander

2013-10-01

The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

Progress in the indirect-drive National Ignition Campaign

International Nuclear Information System (INIS)

Landen, O L; Benedetti, R; Bleuel, D; Bradley, D K; Caggiano, J A; Callahan, D A; Celliers, P M; Cerjan, C J; Clark, D; Collins, G W; Dewald, E L; Dixit, S N; Doeppner, T; Eggert, J; Farley, D; Glenn, S M; Boehly, T R; Edgell, D; Glebov, V; Frenje, J A

2012-01-01

We have carried out precision optimization of inertial confinement fusion ignition scale implosions. We have achieved hohlraum temperatures in excess of the 300 eV ignition goal with hot-spot symmetry and shock timing near ignition specs. Using slower rise pulses to peak power and extended pulses resulted in lower hot-spot adiabat and higher main fuel areal density at about 80% of the ignition goal. Yields are within a factor of 5–6 of that required to initiate alpha dominated burn. It is likely we will require thicker shells (+15–20%) to reach ignition velocity without mixing of ablator material into the hot spot. (paper)

Functional Analysis for Double Shell Tank (DST) Subsystems

International Nuclear Information System (INIS)

SMITH, D.F.

2000-01-01

This functional analysis identifies the hierarchy and describes the subsystem functions that support the Double-Shell Tank (DST) System described in HNF-SD-WM-TRD-007, System Specification for the Double-Shell Tank System. Because of the uncertainty associated with the need for upgrades of the existing catch tanks supporting the Waste Feed Delivery (WFD) mission, catch tank functions are not addressed in this document. The functions identified herein are applicable to the Phase 1 WFD mission only

An Eocene orthocone from Antarctica shows convergent evolution of internally shelled cephalopods

Science.gov (United States)

Bengtson, Stefan; Reguero, Marcelo A.; Mörs, Thomas

2017-01-01

Background The Subclass Coleoidea (Class Cephalopoda) accommodates the diverse present-day internally shelled cephalopod mollusks (Spirula, Sepia and octopuses, squids, Vampyroteuthis) and also extinct internally shelled cephalopods. Recent Spirula represents a unique coleoid retaining shell structures, a narrow marginal siphuncle and globular protoconch that signify the ancestry of the subclass Coleoidea from the Paleozoic subclass Bactritoidea. This hypothesis has been recently supported by newly recorded diverse bactritoid-like coleoids from the Carboniferous of the USA, but prior to this study no fossil cephalopod indicative of an endochochleate branch with an origin independent from subclass Bactritoidea has been reported. Methodology/Principal findings Two orthoconic conchs were recovered from the Early Eocene of Seymour Island at the tip of the Antarctic Peninsula, Antarctica. They have loosely mineralized organic-rich chitin-compatible microlaminated shell walls and broadly expanded central siphuncles. The morphological, ultrustructural and chemical data were determined and characterized through comparisons with extant and extinct taxa using Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS). Conclusions/Significance Our study presents the first evidence for an evolutionary lineage of internally shelled cephalopods with independent origin from Bactritoidea/Coleoidea, indicating convergent evolution with the subclass Coleoidea. A new subclass Paracoleoidea Doguzhaeva n. subcl. is established for accommodation of orthoconic cephalopods with the internal shell associated with a broadly expanded central siphuncle. Antarcticerida Doguzhaeva n. ord., Antarcticeratidae Doguzhaeva n. fam., Antarcticeras nordenskjoeldi Doguzhaeva n. gen., n. sp. are described within the subclass Paracoleoidea. The analysis of organic-rich shell preservation of A. nordenskjoeldi by use of SEM/EDS techniques revealed fossilization of hyposeptal cameral soft tissues

Demonstrating ignition hydrodynamic equivalence in direct-drive cryogenic implosions on OMEGA

International Nuclear Information System (INIS)

Goncharov, V N; Regan, S P; Sangster, T C; Betti, R; Boehly, T R; Campbell, E M; Delettrez, J A; Edgell, D H; Epstein, R; Forrest, C J; Froula, D H; Glebov, V Yu; Harding, D R; Hu, S X; Igumenshchev, I V; Marshall, F J; McCrory, R L; Michel, D T; Myatt, J F; Radha, P B

2016-01-01

Achieving ignition in a direct-drive cryogenic implosion at the National Ignition Facility (NIF) requires reaching central stagnation pressures in excess of 100 Gbar, which is a factor of 3 to 4 less than what is required for indirect-drive designs. The OMEGA Laser System is used to study the physics of cryogenic implosions that are hydrodynamically equivalent to the spherical ignition designs of the NIF. Current cryogenic implosions on OMEGA have reached 56 Gbar, and implosions with shell convergence CR< 17 and fuel adiabat α > 3.5 proceed close to 1-D predictions. Demonstrating hydrodynamic equivalence on OMEGA will require reducing coupling losses caused by cross-beam energy transfer (CBET), minimizing long- wavelength nonuniformity seeded by power imbalance and target offset, and removing target debris occumulated during cryogenic target production. (paper)

Gain curves and hydrodynamic modeling for shock ignition

International Nuclear Information System (INIS)

Lafon, M.; Ribeyre, X.; Schurtz, G.

2010-01-01

Ignition of a precompressed thermonuclear fuel by means of a converging shock is now considered as a credible scheme to obtain high gains for inertial fusion energy. This work aims at modeling the successive stages of the fuel time history, from compression to final thermonuclear combustion, in order to provide the gain curves of shock ignition (SI). The leading physical mechanism at work in SI is pressure amplification, at first by spherical convergence, and by collision with the shock reflected at center during the stagnation process. These two effects are analyzed, and ignition conditions are provided as functions of the shock pressure and implosion velocity. Ignition conditions are obtained from a non-isobaric fuel assembly, for which we present a gain model. The corresponding gain curves exhibit a significantly lower ignition threshold and higher target gains than conventional central ignition.

On the Ideal Convergence of Double Sequences in Locally Solid Riesz Spaces

Directory of Open Access Journals (Sweden)

A. Alotaibi

2014-01-01

Full Text Available The aim of this paper is to define the notions of ideal convergence, I-bounded for double sequences in setting of locally solid Riesz spaces and study some results related to these notions. We also define the notion of I*-convergence for double sequences in locally solid Riesz spaces and establish its relationship with ideal convergence.

Double containment shell for nuclear power plants

International Nuclear Information System (INIS)

Sykora, D.

1977-01-01

A double containment shell is proposed for nuclear power plants, especially those equipped with pressurized water reactors. The shell offers increased environmental protection from primary circuit accidents. The inner shell is built of steel or concrete while the outer shell is always built of concrete. The space between the two shells is filled with water and is provided with several manholes and with stiffeners designed for compensation for load due to the water hydrostatic pressure. Water serves the airtight separation of the containment shell inside from the environment and the absorption of heat released in a primary circuit accident. In case the inner shell is made of concrete, it is provided with heat-removal tubes in-built in its walls ensuring rapid heat transfer from the inside of the containment to the water in the interwall space. (Z.M.)

Derived Requirements for Double Shell Tank (DST) High Level Waste (HLW) Auxiliary Solids Mobilization

Energy Technology Data Exchange (ETDEWEB)

TEDESCHI, A.R.

2000-02-28

The potential need for auxiliary double-shell tank waste mixing and solids mobilization requires an evaluation of optional technologies. This document formalizes those operating and design requirements needed for further engineering evaluations.

Derived Requirements for Double-Shell Tank (DST) High Level Waste (HLW) Auxiliary Solids Mobilization

International Nuclear Information System (INIS)

TEDESCHI, A.R.

2000-01-01

The potential need for auxiliary double-shell tank waste mixing and solids mobilization requires an evaluation of optional technologies. This document formalizes those operating and design requirements needed for further engineering evaluations

Three-dimensional simulations of low foot and high foot implosion experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Clark, D. S.; Weber, C. R.; Milovich, J. L.; Salmonson, J. D.; Kritcher, A. L.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Hurricane, O. A.; Jones, O. S.; Marinak, M. M.; Patel, P. K.; Robey, H. F.; Sepke, S. M.; Edwards, M. J.

2016-01-01

In order to achieve the several hundred Gbar stagnation pressures necessary for inertial confinement fusion ignition, implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] require the compression of deuterium-tritium fuel layers by a convergence ratio as high as forty. Such high convergence implosions are subject to degradation by a range of perturbations, including the growth of small-scale defects due to hydrodynamic instabilities, as well as longer scale modulations due to radiation flux asymmetries in the enclosing hohlraum. Due to the broad range of scales involved, and also the genuinely three-dimensional (3D) character of the flow, accurately modeling NIF implosions remains at the edge of current simulation capabilities. This paper describes the current state of progress of 3D capsule-only simulations of NIF implosions aimed at accurately describing the performance of specific NIF experiments. Current simulations include the effects of hohlraum radiation asymmetries, capsule surface defects, the capsule support tent and fill tube, and use a grid resolution shown to be converged in companion two-dimensional simulations. The results of detailed simulations of low foot implosions from the National Ignition Campaign are contrasted against results for more recent high foot implosions. While the simulations suggest that low foot performance was dominated by ablation front instability growth, especially the defect seeded by the capsule support tent, high foot implosions appear to be dominated by hohlraum flux asymmetries, although the support tent still plays a significant role. For both implosion types, the simulations show reasonable, though not perfect, agreement with the data and suggest that a reliable predictive capability is developing to guide future implosions toward ignition.

Three-dimensional simulations of low foot and high foot implosion experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Clark, D. S.; Weber, C. R.; Milovich, J. L.; Salmonson, J. D.; Kritcher, A. L.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Hurricane, O. A.; Jones, O. S.; Marinak, M. M.; Patel, P. K.; Robey, H. F.; Sepke, S. M.; Edwards, M. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

2016-05-15

In order to achieve the several hundred Gbar stagnation pressures necessary for inertial confinement fusion ignition, implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] require the compression of deuterium-tritium fuel layers by a convergence ratio as high as forty. Such high convergence implosions are subject to degradation by a range of perturbations, including the growth of small-scale defects due to hydrodynamic instabilities, as well as longer scale modulations due to radiation flux asymmetries in the enclosing hohlraum. Due to the broad range of scales involved, and also the genuinely three-dimensional (3D) character of the flow, accurately modeling NIF implosions remains at the edge of current simulation capabilities. This paper describes the current state of progress of 3D capsule-only simulations of NIF implosions aimed at accurately describing the performance of specific NIF experiments. Current simulations include the effects of hohlraum radiation asymmetries, capsule surface defects, the capsule support tent and fill tube, and use a grid resolution shown to be converged in companion two-dimensional simulations. The results of detailed simulations of low foot implosions from the National Ignition Campaign are contrasted against results for more recent high foot implosions. While the simulations suggest that low foot performance was dominated by ablation front instability growth, especially the defect seeded by the capsule support tent, high foot implosions appear to be dominated by hohlraum flux asymmetries, although the support tent still plays a significant role. For both implosion types, the simulations show reasonable, though not perfect, agreement with the data and suggest that a reliable predictive capability is developing to guide future implosions toward ignition.

Direct-drive–ignition designs with mid-Z ablators

Energy Technology Data Exchange (ETDEWEB)

Lafon, M.; Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Anderson, K. S.; Collins, T. J. B.; Epstein, R.; McKenty, P. W.; Myatt, J. F.; Shvydky, A.; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-03-15

Achieving thermonuclear ignition using direct laser illumination relies on the capability to accelerate spherical shells to high implosion velocities while maintaining shell integrity. Ablator materials of moderate atomic number Z reduce the detrimental effects of laser–plasma instabilities in direct-drive implosions. To validate the physics of moderate-Z ablator materials for ignition target designs on the National Ignition Facility (NIF), hydro-equivalent targets are designed using pure plastic (CH), high-density carbon, and glass (SiO{sub 2}) ablators. The hydrodynamic stability of these targets is investigated through two-dimensional (2D) single-mode and multimode simulations. The overall stability of these targets to laser-imprint perturbations and low-mode asymmetries makes it possible to design high-gain targets. Designs using polar-drive illumination are developed within the NIF laser system specifications. Mid-Z ablator targets are an attractive candidate for direct-drive ignition since they present better overall performance than plastic ablator targets through reduced laser–plasma instabilities and a similar hydrodynamic stability.

Microwave-Assisted Synthesis of NiCo2O4 Double-Shelled Hollow Spheres for High-Performance Sodium Ion Batteries

Science.gov (United States)

Zhang, Xiong; Zhou, Yanping; Luo, Bin; Zhu, Huacheng; Chu, Wei; Huang, Kama

2018-03-01

The ternary transitional metal oxide NiCo2O4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo2O4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt, and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized product was tested as an anode material in a sodium ion battery, was found to exhibit a high reversible specific capacity of 511 mAh g-1 at 100 mA g-1, and deliver high capacity retention after 100 cycles. [Figure not available: see fulltext.

Double-shell Fe2O3 hollow box-like structure for enhanced photo-Fenton degradation of malachite green dye

Science.gov (United States)

Jiang, De Bin; Liu, Xiaoying; Xu, Xuan; Zhang, Yu Xin

2018-01-01

In this work we demonstrate the synthesis of novel Fe2O3 nanosheets with double-shell hollow morphology by replica molding from diatomite framework. The nanostructures of Fe2O3 nanosheets were examined by focused-ion-beam scanning electron microscopy (FIB/SEM), X-ray diffraction spectroscopy (XRD), Brunauer-Emmett-Teller (BET) specific surface area measurements and Fourier transform infrared (FT-IR) spectroscopy. The results reveal that (1) Pure Fe2O3 nanosheets were successfully obtained; (2) The double-shell Fe2O3 hollow structure achieved via the NaOH etching silica method was observed; (3) Fe2O3 nanosheets possessed uniformly distributed porous nanosheets. Such structural features enlarged the specific surface area of Fe2O3 nanosheets and led to more catalytic active sites. In the heterogeneous photo-Fenton reaction, the double-shell Fe2O3 hollow morphology exhibited excellent catalytic capability for the degradation of malachite green (MG) at circumneutral pH condition. Under optimum condition, MG solution was almost completely decolorized in 60 min (99.9%). The Fe2O3 nanosheets also showed good stability and recyclability, demonstrating great potential as a promising photo-Fenton catalyst for the effective degradation of MG dye in wastewater.

The volume ignition for ICF ignition target

International Nuclear Information System (INIS)

Li, Y. S.; He, X. T.; Yu, M.

1997-01-01

Compared with central model, volume ignition has no hot spot, avoids the mixing at the hot-cold interface, the α-particle escaping, and the high convergence, greatly reduces the sharp demanding for uniformity. In laser indirect driving, from theoretical estimation and computational simulation, we have proved that using a tamper with good heat resistance, the DT fuel can be ignited in LTE at ∼3 KeV and then evolves to the non-LTE ignition at >5 KeV. In this case, 1 MJ radiation energy in the hohlraum could cause near 10 MJ output for a pellet with 0.2 mg DT fuel. We have compared results with and without α-particle transport, it shows that in the condition of ρR>0.5 g/cm 2 of DT fuel, both have the same results. For the system with ρR≅0.5 g/cm 2 we can use α-particle local deposition scheme. The non-uniformly doped tamper with density ρ≅1-5 g/cc can reduce mixing due to the small convergence ratio. The input energy is deposited in DT and tamper during the implosion, we try to reduce the tamper energy by changing the ratio of CH and doped Au and the thickness of the tamper

Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

International Nuclear Information System (INIS)

Clark, D. S.; Haan, S. W.; Cook, A. W.; Edwards, M. J.; Hammel, B. A.; Koning, J. M.; Marinak, M. M.

2011-01-01

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

The effects of convergence ratio on the implosion behavior of DT layered inertial confinement fusion capsules

Science.gov (United States)

Haines, Brian M.; Yi, S. A.; Olson, R. E.; Khan, S. F.; Kyrala, G. A.; Zylstra, A. B.; Bradley, P. A.; Peterson, R. R.; Kline, J. L.; Leeper, R. J.; Shah, R. C.

2017-07-01

The wetted foam capsule design for inertial confinement fusion capsules, which includes a foam layer wetted with deuterium-tritium liquid, enables layered capsule implosions with a wide range of hot-spot convergence ratios (CR) on the National Ignition Facility. We present a full-scale wetted foam capsule design that demonstrates high gain in one-dimensional simulations. In these simulations, increasing the convergence ratio leads to an improved capsule yield due to higher hot-spot temperatures and increased fuel areal density. High-resolution two-dimensional simulations of this design are presented with detailed and well resolved models for the capsule fill tube, support tent, surface roughness, and predicted asymmetries in the x-ray drive. Our modeling of these asymmetries is validated by comparisons with available experimental data. In 2D simulations of the full-scale wetted foam capsule design, jetting caused by the fill tube is prevented by the expansion of the tungsten-doped shell layer due to preheat. While the impacts of surface roughness and predicted asymmetries in the x-ray drive are enhanced by convergence effects, likely underpredicted in 2D at high CR, simulations predict that the capsule is robust to these features. Nevertheless, the design is highly susceptible to the effects of the capsule support tent, which negates all of the one-dimensional benefits of increasing the convergence ratio. Indeed, when the support tent is included in simulations, the yield decreases as the convergence ratio is increased for CR > 20. Nevertheless, the results suggest that the full-scale wetted foam design has the potential to outperform ice layer capsules given currently achievable levels of asymmetries when fielded at low convergence ratios (CR < 20).

A methodology to define the flow rate and pressure requirements for transfer of double-shell tank waste slurries

International Nuclear Information System (INIS)

Bamberger, J.A.; Liljegren, L.M.

1993-04-01

This document presents an analysis of the pressure drop and flow rate double-shell tank slurries. Experiments to requirements for transport of characterize the transport of double-shell tank slurries through piping networks and to resuspend materials that settle during pump outages are proposed. Reported values of physical properties of double-shell tank slurries were analyzed to evaluate the flow regimes that are likely to occur during transport. The results of these evaluations indicate that the slurry will be pseudohomogeneous during transport and that the slurry rheology is sufficiently non-Newtonian to affect both the pressure drop achieved during transport and the critical Reynolds number. The transport data collected in the non-Newtonian experiment will be used to determine whether a non-Newtonian correlation developed by Hanks (1978) adequately describes the experimental results

Adiabatic Quasi-Spherical Compressions Driven by Magnetic Pressure for Inertial Confinement Fusion

International Nuclear Information System (INIS)

Nash, Thomas J.

2000-01-01

The magnetic implosion of a high-Z quasi-spherical shell filled with DT fuel by the 20-MA Z accelerator can heat the fuel to near-ignition temperature. The attainable implosion velocity on Z, 13-cm/micros, is fast enough that thermal losses from the fuel to the shell are small. The high-Z shell traps radiation losses from the fuel, and the fuel reaches a high enough density to reabsorb the trapped radiation. The implosion is then nearly adiabatic. In this case the temperature of the fuel increases as the square of the convergence. The initial temperature of the fuel is set by the heating of an ion acoustic wave to be about 200-eV after a convergence of 4. To reach the ignition temperature of 5-keV an additional convergence of 5 is required. The implosion dynamics of the quasi-spherical implosion is modeled with the 2-D radiation hydrodynamic code LASNEX. LASNEX shows an 8-mm diameter quasi-spherical tungsten shell on Z driving 6-atmospheres of DT fuel nearly to ignition at 3.5-keV with a convergence of 20. The convergence is limited by mass flow along the surface of the quasi-spherical shell. With a convergence of 20 the final spot size is 400-microm in diameter

Constraints for system specifications for the double-shell and single-shell tank systems

International Nuclear Information System (INIS)

SHAW, C.P.

1999-01-01

This is a supporting document for the Level 1 Double-Shell and Single-Shell System Specifications. The rationale for selection of specific regulatory constraining documents cited in the two system specifications is provided. many of the regulations have been implemented by the Project Hanford Management Contract procedures (HNF-PROs) and as such noted and traced back to their origins in State and Federal regulations

Constraints for system specifications for the double-shell and single-shell tank systems

Energy Technology Data Exchange (ETDEWEB)

SHAW, C.P.

1999-05-18

This is a supporting document for the Level 1 Double-Shell and Single-Shell System Specifications. The rationale for selection of specific regulatory constraining documents cited in the two system specifications is provided. many of the regulations have been implemented by the Project Hanford Management Contract procedures (HNF-PROs) and as such noted and traced back to their origins in State and Federal regulations.

Progress of impact ignition

International Nuclear Information System (INIS)

Murakami, M.; Nagatomo, H.; Johzaki, T.

2010-11-01

In impact ignition scheme, a portion of the fuel (the impactor) is accelerated to a super-high velocity, compressed by convergence, and collided with a precompressed main fuel. This collision generates shock waves in both the impactor and the main fuel. Since the density of the impactor is generally much lower than that of the main fuel, the pressure balance ensures that the shock-heated temperature of the impactor is significantly higher than that of the main fuel. Hence, the impactor can reach ignition temperature and thus become an igniter. Here we report major new results on recent impact ignition research: (1) A maximum velocity ∼ 1000 km/s has been achieved under the operation of NIKE KrF laser at Naval Research Laboratory (laser wavelength=0.25μm) in the use of a planar target made of plastic and (2) We have performed two-dimensional simulation for burn and ignition to show the feasibility of the impact ignition. (author)

Pd@Pt Core–Shell Nanoparticles with Branched Dandelion-like Morphology as Highly Efficient Catalysts for Olefin Reduction

Science.gov (United States)

A facile synthesis based on the addition of ascorbic acid to a mixture of Na2PdCl4, K2PtCl6, and Pluronic P123 results in highly branched core–shell nanoparticles (NPs) with a micro–mesoporous dandelion-like morphology comprising Pd core and Pt shell. The slow reduction kinetics ...

Double-shell tank emergency pumping guide

International Nuclear Information System (INIS)

BROWN, M.H.

1999-01-01

This Double-Shell Tank Emergency Pumping Guide provides the preplanning necessary to expeditiously remove any waste that may leak from the primary tank to the secondary tank for Hanfords 28 DSTs. The strategy is described, applicable emergency procedures are referenced, and transfer routes and pumping equipment for each tank are identified

Double-shell tank emergency pumping guide

International Nuclear Information System (INIS)

BROWN, M.H.

1999-01-01

This Double-Shell Tank Emergency Pumping Guide provides the preplanning necessary to expeditiously remove any waste that may leak from the primary tank to the secondary tank for Hanford's 28 DSTS. The strategy is described, applicable emergency procedures are referenced, and transfer routes and pumping equipment for each tank are identified

Hydrodynamic modelling of the shock ignition scheme for inertial confinement fusion

International Nuclear Information System (INIS)

Vallet, Alexandra

2014-01-01

The shock ignition concept in inertial confinement fusion uses an intense power spike at the end of an assembly laser pulse. The key features of shock ignition are the generation of a high ablation pressure, the shock pressure amplification by at least a factor of a hundred in the cold fuel shell and the shock coupling to the hot-spot. In this thesis, new semi-analytical hydrodynamic models are developed to describe the ignitor shock from its generation up to the moment of fuel ignition. A model is developed to describe a spherical converging shock wave in a pre-heated hot spot. The self-similar solution developed by Guderley is perturbed over the shock Mach number Ms ≥≥1. The first order correction accounts for the effects of the shock strength. An analytical ignition criterion is defined in terms of the shock strength and the hot-spot areal density. The ignition threshold is higher when the initial Mach number of the shock is lower. A minimal shock pressure of 20 Gbar is needed when it enters the hot-spot. The shock dynamics in the imploding shell is then analyzed. The shock is propagating into a non inertial medium with a high radial pressure gradient and an overall pressure increase with time. The collision with a returning shock coming from the assembly phase enhances further the ignitor shock pressure. The analytical theory allows to describe the shock pressure and strength evolution in a typical shock ignition implosion. It is demonstrated that, in the case of the HiPER target design, a generation shock pressure near the ablation zone on the order of 300-400 Mbar is needed. An analysis of experiments on the strong shock generation performed on the OMEGA laser facility is presented. It is shown that a shock pressure close to 300 Mbar near the ablation zone has been reached with an absorbed laser intensity up to 2 * 10 15 W:cm -2 and a laser wavelength of 351 nm. This value is two times higher than the one expected from collisional laser absorption only

Progress towards ignition on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Edwards, M. J.; Patel, P. K.; Lindl, J. D.; Atherton, L. J.; Glenzer, S. H.; Haan, S. W.; Landen, O. L.; Moses, E. I.; Springer, P. T.; Benedetti, R.; Bernstein, L.; Bleuel, D. L.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C. J.; Clark, D. S.; Collins, G. W.; Dewald, E. L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); and others

2013-07-15

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory includes a precision laser system now capable of delivering 1.8 MJ at 500 TW of 0.35-μm light to a target. NIF has been operational since March 2009. A variety of experiments have been completed in support of NIF's mission areas: national security, fundamental science, and inertial fusion energy. NIF capabilities and infrastructure are in place to support its missions with nearly 60 X-ray, optical, and nuclear diagnostic systems. A primary goal of the National Ignition Campaign (NIC) on the NIF was to implode a low-Z capsule filled with ∼0.2 mg of deuterium-tritium (DT) fuel via laser indirect-drive inertial confinement fusion and demonstrate fusion ignition and propagating thermonuclear burn with a net energy gain of ∼5–10 (fusion yield/input laser energy). This requires assembling the DT fuel into a dense shell of ∼1000 g/cm{sup 3} with an areal density (ρR) of ∼1.5 g/cm{sup 2}, surrounding a lower density hot spot with a temperature of ∼10 keV and a ρR ∼0.3 g/cm{sup 2}, or approximately an α-particle range. Achieving these conditions demand precise control of laser and target parameters to allow a low adiabat, high convergence implosion with low ablator fuel mix. We have demonstrated implosion and compressed fuel conditions at ∼80–90% for most point design values independently, but not at the same time. The nuclear yield is a factor of ∼3–10× below the simulated values and a similar factor below the alpha dominated regime. This paper will discuss the experimental trends, the possible causes of the degraded performance (the off-set from the simulations), and the plan to understand and resolve the underlying physics issues.

Chemically ignited thermonuclear reactions: A near-term means for a high specific impulse - High thrust propulsion system

International Nuclear Information System (INIS)

Winterberg, F.

1982-01-01

A proposal for the fissionless ignition of small thermonuclear reactions is made which involves the combination of the magnetic booster target inertial fusion concept with the chemical implosion of metallic shells. The magnetic booster employs a very dense and magnetically confined low yield thermonuclear plasma to trigger an inertially confined high yield plasma. Fissionless ignition permits smaller yields than with fission- or fusion-induced fusion bombs, yields that are appropriate for use in a spacecraft propulsion system. Each bomb would release about 10 to the 18th erg or 100 tons of TNT, and with one explosion per second, an average thrust of 10 to the third tons and a specific impulse of about 3000 seconds can be expected

Influence of laser induced hot electrons on the threshold for shock ignition of fusion reactions

Energy Technology Data Exchange (ETDEWEB)

Colaïtis, A.; Ribeyre, X.; Le Bel, E.; Duchateau, G.; Nicolaï, Ph.; Tikhonchuk, V. [Centre Lasers Intenses et Applications, Université de Bordeaux - CNRS - CEA, UMR 5107,351 Cours de la Libération, 33400 Talence (France)

2016-07-15

The effects of Hot Electrons (HEs) generated by the nonlinear Laser-Plasma Interaction (LPI) on the dynamics of Shock Ignition Inertial Confinement Fusion targets are investigated. The coupling between the laser beam, plasma dynamics and hot electron generation and propagation is described with a radiative hydrodynamics code using an inline model based on Paraxial Complex Geometrical Optics [Colaïtis et al., Phys. Rev. E 92, 041101 (2015)]. Two targets are considered: the pure-DT HiPER target and a CH-DT design with baseline spike powers of the order of 200–300 TW. In both cases, accounting for the LPI-generated HEs leads to non-igniting targets when using the baseline spike powers. While HEs are found to increase the ignitor shock pressure, they also preheat the bulk of the imploding shell, notably causing its expansion and contamination of the hotspot with the dense shell material before the time of shock convergence. The associated increase in hotspot mass (i) increases the ignitor shock pressure required to ignite the fusion reactions and (ii) significantly increases the power losses through Bremsstrahlung X-ray radiation, thus rapidly cooling the hotspot. These effects are less prominent for the CH-DT target where the plastic ablator shields the lower energy LPI-HE spectrum. Simulations using higher laser spike powers of 500 TW suggest that the CH-DT capsule marginally ignites, with an ignition window width significantly smaller than without LPI-HEs, and with three quarters of the baseline target yield. The latter effect arises from the relation between the shock launching time and the shell areal density, which becomes relevant in presence of a LPI-HE preheating.

Analysis and characterization of double shell tank 241-AP-108

International Nuclear Information System (INIS)

Miller, G.L.

1994-01-01

This document is the first part of a three-part report describing the analysis and characterization of double shell tank 241-AP-108 which is located at the Hanford Reservation.This document is the analytical laboratory data package entitled 'Analysis and Characterization of Double Shell Tank 241-AP-108' which contains a case sampling history, the sampling protocols, the analytical procedures, sampling and analysis quality assurance and quality control measures, and chemical analysis results for samples obtained from the tank

Analytical criterion for shock ignition of fusion reaction in hot spot

International Nuclear Information System (INIS)

Ribeyre, X.; Tikhonchuk, V. T.; Breil, J.; Lafon, M.; Vallet, A.; Bel, E. L.

2013-01-01

Shock ignition of DT capsules involves two major steps. First, the fuel is assembled by means of a low velocity conventional implosion. At stagnation, the central core has a temperature lower than the one needed for ignition. Then a second, strong spherical converging shock, launched from a high intensity laser spike, arrives to the core. This shock crosses the core, rebounds at the target center and increases the central pressure to the ignition conditions. In this work we consider this latter phase by using the Guderley self-similar solution for converging flows. Our model accounts for the fusion reaction energy deposition, thermal and radiation losses thus describing the basic physics of hot spot ignition. The ignition criterion derived from the analytical model is successfully compared with full scale hydrodynamic simulations. (authors)

Hanford double shell tank corrosion monitoring instrument trees

International Nuclear Information System (INIS)

Nelson, J.L.

1995-03-01

High-level nuclear wastes at the Hanford site are stored underground in carbon steel double-shell and single-shell tanks - (DSTs and SSTS). Westinghouse Hanford Company is considering installation of a prototype corrosion monitoring instrument tree in at least one DST in the summer of 1995. The instrument tree will have the ability to detect and discriminate between uniform corrosion, stress corrosion cracking (SCC), and pitting. Additional instrument trees will follow in later years. Proof-of-technology testing is currently underway for the use of commercially available electric field pattern (EFP) analysis and electrochemical noise (EN) corrosion monitoring equipment. Creative use and combinations of other existing technologies is also being considered. Successful demonstration of these technologies will be followed by the development of a Hanford specific instrument tree. The first instrument tree will incorporate one of these technologies. Subsequent trees may include both technologies, as well as a more standard assembly of corrosion coupons. Successful development of these trees will allow their application to single shell tanks and the transfer of technology to other U.S. Department of Energy (DOE) sites

Preventing Buoyant Displacement Gas Release Events in Hanford Double-Shell Waste Tanks

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Stewart, Charles W.

2001-01-01

This report summarizes the predictive methods used to ensure that waste transfer operations in Hanford waste tanks do not create waste configurations that lead to unsafe gas release events. The gas release behavior of the waste in existing double-shell tanks has been well characterized, and the flammable gas safety issues associated with safe storage of waste in the current configuration are being formally resolved. However, waste is also being transferred between double-shell tanks and from single-shell tanks into double-shell tanks by saltwell pumping and sluicing that create new wastes and waste configurations that have not been studied as well. Additionally, planning is underway for various waste transfer scenarios to support waste feed delivery to the proposed vitrification plant. It is critical that such waste transfers do not create waste conditions with the potential for dangerous gas release events.

Corrections to the neutrinoless double-β-decay operator in the shell model

Science.gov (United States)

Engel, Jonathan; Hagen, Gaute

2009-06-01

We use diagrammatic perturbation theory to construct an effective shell-model operator for the neutrinoless double-β decay of Se82. The starting point is the same Bonn-C nucleon-nucleon interaction that is used to generate the Hamiltonian for recent shell-model calculations of double-β decay. After first summing high-energy ladder diagrams that account for short-range correlations and then adding diagrams of low order in the G matrix to account for longer-range correlations, we fold the two-body matrix elements of the resulting effective operator with transition densities from the recent shell-model calculation to obtain the overall nuclear matrix element that governs the decay. Although the high-energy ladder diagrams suppress this matrix element at very short distances as expected, they enhance it at distances between one and two fermis, so that their overall effect is small. The corrections due to longer-range physics are large, but cancel one another so that the fully corrected matrix element is comparable to that produced by the bare operator. This cancellation between large and physically distinct low-order terms indicates the importance of a reliable nonperturbative calculation.

Double-shell tank system dangerous waste permit application

International Nuclear Information System (INIS)

1991-06-01

This appendix contains the engineering design drawings for the double-shell tank system. Included are drawings of the electrical systems, structural members, piping systems, instrumentation and the many auxiliary systems. (JL)

High frequency ignition arrangement

Energy Technology Data Exchange (ETDEWEB)

Canup, R E

1977-03-03

The invention concerns an HF ignition arrangement for combustion engines with a transistor oscillator. As this oscillator requires a current of 10A, with peak currents up to about 50A, it is not sensible to take this current through the remote ignition switch for switching it on and off. According to the invention the HF high voltage transformer of the ignition is provided with a control winding, which only requires a few milliamps DC and which can therefore be switched via the ignition switch. If the ignition switch is in the 'running' position, then a premagnetising DC current flows through the control winding, which suppresses the oscillation of the oscillator which has current flowing through it, until this current is interrupted by the interruptor contacts controlled by the combustion engine, so that the oscillations of the oscillator start immediately; the oscillator only continues to oscillate during the period during which the interruptor contacts controlled by the machine are open and interrupt the premagnetisation current. The control winding is short circuited in the 'off' position of the ignition switch.

Pion-nucleus double charge exchange and the nuclear shell model

International Nuclear Information System (INIS)

Auerbach, N.; Gibbs, W.R.; Ginocchio, J.N.; Kaufmann, W.B.

1988-01-01

The pion-nucleus double charge exchange reaction is studied with special emphasis on nuclear structure. The reaction mechanism and nuclear structure aspects of the process are separated using both the plane-wave and distorted-wave impulse approximations. Predictions are made employing both the seniority model and a full shell model (with a single active orbit). Transitions to the double analog state and to the ground state of the residual nucleus are computed. The seniority model yields particularly simple relations among double charge exchange cross sections for nuclei within the same shell. Limitations of the seniority model and of the plane-wave impulse approximation are discussed as well as extensions to the generalized seniority scheme. Applications of the foregoing ideas to single charge exchange are also presented

Convergent Double Auction Mechanism for a Prosumers’ Decentralized Smart Grid

Directory of Open Access Journals (Sweden)

Tadahiro Taniguchi

2015-10-01

Full Text Available In this paper, we propose a novel automated double auction mechanism called convergent linear function submission-based double-auction (CLFS-DA for a prosumers’ decentralized smart grid. The target decentralized smart grid is a regional electricity network that consists of many prosumers that have a battery and a renewable energy-based generator, such as photovoltaic cells. In the proposed double-auction mechanism, each intelligent software agent representing each prosumer submits linear demand and supply functions to an automated regional electricity market where they are registered. It is proven that the CLFS-DA mechanism is guaranteed to obtain one of the global optimal price profiles in addition to it achieving an exact balance between demand and supply, even through the learning period. The proof of convergence is provided on the basis of the theory of LFS-DA, which gives a clear bridge between a function submission-based double auction and a dual decomposition (DD-based real-time pricing procedure. The performance of the proposed mechanism is demonstrated numerically through a simulation experiment.

ESTIMATING HIGH LEVEL WASTE MIXING PERFORMANCE IN HANFORD DOUBLE SHELL TANKS

International Nuclear Information System (INIS)

Thien, M.G.; Greer, D.A.; Townson, P.

2011-01-01

The ability to effectively mix, sample, certify, and deliver consistent batches of high level waste (HLW) feed from the Hanford double shell tanks (DSTs) to the Waste Treatment and Immobilization Plant (WTP) presents a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. The Department of Energy's (DOE's) Tank Operations Contractor (TOC), Washington River Protection Solutions (WRPS) is currently demonstrating mixing, sampling, and batch transfer performance in two different sizes of small-scale DSTs. The results of these demonstrations will be used to estimate full-scale DST mixing performance and provide the key input to a programmatic decision on the need to build a dedicated feed certification facility. This paper discusses the results from initial mixing demonstration activities and presents data evaluation techniques that allow insight into the performance relationships of the two small tanks. The next steps, sampling and batch transfers, of the small scale demonstration activities are introduced. A discussion of the integration of results from the mixing, sampling, and batch transfer tests to allow estimating full-scale DST performance is presented.

Progress in detailed modelling of low foot and high foot implosion experiments on the National Ignition Facility

Science.gov (United States)

Clark, D. S.; Weber, C. R.; Eder, D. C.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Jones, O. S.; Kritcher, A. L.; Marinak, M. M.; Milovich, J. L.; Patel, P. K.; Robey, H. F.; Salmonson, J. D.; Sepke, S. M.

2016-05-01

Several dozen high convergence inertial confinement fusion ignition experiments have now been completed on the National Ignition Facility (NIF). These include both “low foot” experiments from the National Ignition Campaign (NIC) and more recent “high foot” experiments. At the time of the NIC, there were large discrepancies between simulated implosion performance and experimental data. In particular, simulations over predicted neutron yields by up to an order of magnitude, and some experiments showed clear evidence of mixing of ablator material deep into the hot spot that could not be explained at the time. While the agreement between data and simulation improved for high foot implosion experiments, discrepancies nevertheless remain. This paper describes the state of detailed modelling of both low foot and high foot implosions using 1-D, 2-D, and 3-D radiation hydrodynamics simulations with HYDRA. The simulations include a range of effects, in particular, the impact of the plastic membrane used to support the capsule in the hohlraum, as well as low-mode radiation asymmetries tuned to match radiography measurements. The same simulation methodology is applied to low foot NIC implosion experiments and high foot implosions, and shows a qualitatively similar level of agreement for both types of implosions. While comparison with the experimental data remains imperfect, a reasonable level of agreement is emerging and shows a growing understanding of the high-convergence implosions being performed on NIF.

Progress in detailed modelling of low foot and high foot implosion experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Clark, D S; Weber, C R; Eder, D C; Haan, S W; Hammel, B A; Hinkel, D E; Jones, O S; Kritcher, A L; Marinak, M M; Milovich, J L; Patel, P K; Robey, H F; Salmonson, J D; Sepke, S M

2016-01-01

Several dozen high convergence inertial confinement fusion ignition experiments have now been completed on the National Ignition Facility (NIF). These include both “low foot” experiments from the National Ignition Campaign (NIC) and more recent “high foot” experiments. At the time of the NIC, there were large discrepancies between simulated implosion performance and experimental data. In particular, simulations over predicted neutron yields by up to an order of magnitude, and some experiments showed clear evidence of mixing of ablator material deep into the hot spot that could not be explained at the time. While the agreement between data and simulation improved for high foot implosion experiments, discrepancies nevertheless remain. This paper describes the state of detailed modelling of both low foot and high foot implosions using 1-D, 2-D, and 3-D radiation hydrodynamics simulations with HYDRA. The simulations include a range of effects, in particular, the impact of the plastic membrane used to support the capsule in the hohlraum, as well as low-mode radiation asymmetries tuned to match radiography measurements. The same simulation methodology is applied to low foot NIC implosion experiments and high foot implosions, and shows a qualitatively similar level of agreement for both types of implosions. While comparison with the experimental data remains imperfect, a reasonable level of agreement is emerging and shows a growing understanding of the high-convergence implosions being performed on NIF. (paper)

Structural qualification of the multifunctional instrument tree for installation in double-shell and 100-series single-shell tanks

International Nuclear Information System (INIS)

Strohlow, J.P.

1995-12-01

This document provides the technical basis and methodology for qualifying the multifunctional instrument tree (MIT) structure for installation in double-shell and 100-series single-shell tanks. Structural qualification for MIT installations in specific tanks are also contained in this document

Double Shell Tank (DST) Transfer Piping Subsystem Specification

International Nuclear Information System (INIS)

GRAVES, C.E.

2000-01-01

This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Piping Subsystem that supports the first phase of Waste Feed Delivery. This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Transfer Piping Subsystem that supports the first phase of waste feed delivery. This subsystem transfers waste between transfer-associated structures (pits) and to the River Protection Project (RPP) Privatization Contractor Facility where it will be processed into an immobilized waste form. This specification is intended to be the basis for new projects/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

Simulations of beam-fueled supershot-like plasmas near ignition

International Nuclear Information System (INIS)

Budny, R.V.; Grisham, L.; Jassby, D.L.

1992-01-01

In certain conditions, neutral beam injection (NBI) and low recycling result in supershot plasmas. These are characterized by peaked density profiles and high central ion temperatures. We discuss the potential advantages of NBI fueled supershot-like plasmas in tokamaks operating near ignition. The goal is to investigate the feasibility of these plasmas to aid in the design of future advanced tokamaks. NBI has been very successful in advancing tokamak plasmas close to ignition conditions. The primary benefits of NBI are heating and particle fueling, but the plasma currents generated by the beam ions are also of considerable interest. The optimal injection energy E inj for the beam ions depends on the desired role of the NBI. For central particle fueling, E inj should be low to maximize the particle current at fixed P B , but high enough to penetrate to the center. For heating and current drive, higher E inj is preferable for deepest penetration. With the standard positive ion beam technology, the neutralization efficiency becomes too low for useful power densities if E inj is significantly greater than about 120 keV. Negative ion beam sources would be useful for heating and current drive at very high E inj (500 keV or more), but the fueling rate of NBI is too low to be practical. It seems generally accepted that future tokamaks which operate closer to ignition will have to be fueled and heated by means other than NBI since it is argued that the beams with low E inj cannot penetrate deeply into the dense plasmas of interest. (author) 3 refs., 4 figs

FABRICATION AND CHARACTERIZATION OF FAST IGNITION TARGETS

International Nuclear Information System (INIS)

HILL, D.W; CASTILLO, E; CHEN, K.C; GRANT, S.E; GREENWOOD, A.L; KAAE, J.L; NIKROO, A; PAGUIO, S.P; SHEARER, C; SMITH, J.N Jr.; STEPHENS, R.B; STEINMAN, D.A; WALL, J.

2003-09-01

OAK-B135 Fast ignition is a novel scheme for achieving laser fusion. A class of these targets involves cone mounted CH shells. The authors have been fabricating such targets with shells with a wide variety of diameters and wall thicknesses for several years at General Atomics. In addition, recently such shells were needed for implosion experiments at Laboratory for Laser Energetics (LLE) that for the first time were required to be gas retentive. Fabrication of these targets requires producing appropriate cones and shells, assembling the targets, and characterization of the assembled targets. The cones are produced using micromachining and plating techniques. The shells are fabricated using the depolymerizable mandrel technique followed by micromachining a hole for the cone. The cone and the shell then need to be assembled properly for gas retention and precisely in order to position the cone tip at the desired position within the shell. Both are critical for the fast ignition experiments. The presence of the cone in the shell creates new challenges in characterization of the assembled targets. Finally, for targets requiring a gas fill, the cone-shell assembly needs to be tested for gas retention and proper strength at the glue joint. This paper presents an overview of the developmental efforts and technical issues addressed during the fabrication of fast ignition targets

Double-shell target fabrication workshop-2016 report

Energy Technology Data Exchange (ETDEWEB)

Wang, Y. Morris [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oertel, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Farrell, Michael [General Atomics, San Diego, CA (United States); Baumann, Ted [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Huang, Haibo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nikroo, Abbas [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-01-10

On June 30, 2016, over 40 representatives from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), General Atomics (GA), Laboratory for Laser Energetics (LLE), Schafer Corporation, and NNSA headquarter attended a double-shell (DS) target fabrication workshop at Livermore, California. Pushered-single-shell (PSS) and DS metalgas platforms potentially have a large impact on programmatic applications. The goal of this focused workshop is to bring together target fabrication scientists, physicists, and designers to brainstorm future PSS and DS target fabrication needs and strategies. This one-day workshop intends to give an overall view of historical information, recent approaches, and future research activities at each participating organization. Five topical areas have been discussed that are vital to the success of future DS target fabrications, including inner metal shells, foam spheres, outer ablators, fill tube assembly, and metrology.

Hanford Double-Shell Tank Extent-of-Condition Construction Review

International Nuclear Information System (INIS)

Venetz, Theodore J.; Johnson, Jeremy M.; Gunter, Jason R.; Barnes, Travis J.; Washenfelder, Dennis J.; Boomer, Kayle D.

2013-01-01

During routine visual inspections of Hanford double-shell waste tank 241-AY-102 (AY-102), anomalies were identified on the annulus floor which resulted in further evaluations. Following a formal leak assessment in October 2012, Washington River Protection Solutions, LLC (WRPS) determined that the primary tank of AY-102 was leaking. The formal leak assessment, documented in RPP-ASMT-53793,Tank 241-AY-102 Leak Assessment Report, identified first-of-a-kind construction difficulties and trial-and-error repairs as major contributing factors to tank failure. To determine if improvements in double-shell tank (DST) construction occurred after construction of tank AY-102, a detailed review and evaluation of historical construction records were performed for the first three DST tank farms constructed, which included tanks 241-AY-101, 241-AZ-101, 241-AZ-102, 241-SY-101, 241-SY-102, and 241-SY-103. The review for these six tanks involved research and review of dozens of boxes of historical project documentation. These reviews form a basis to better understand the current condition of the three oldest Hanford DST farms. They provide a basis for changes to the current tank inspection program and also provide valuable insight into future tank use decisions. If new tanks are constructed in the future, these reviews provide valuable 'lessons-learned' information about expected difficulties as well as construction practices and techniques that are likely to be successful

Diagnosing and controlling mix in National Ignition Facility implosion experiments

International Nuclear Information System (INIS)

Hammel, B. A.; Scott, H. A.; Cerjan, C.; Clark, D. S.; Edwards, M. J.; Glenzer, S. H.; Haan, S. W.; Izumi, N.; Koch, J. A.; Landen, O. L.; Langer, S. H.; Smalyuk, V. A.; Suter, L. J.; Regan, S. P.; Epstein, R.; Kyrala, G. A.; Wilson, D. C.; Peterson, K.

2011-01-01

High mode number instability growth of ''isolated defects'' on the surfaces of National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] capsules can be large enough for the perturbation to penetrate the imploding shell, and produce a jet of ablator material that enters the hot-spot. Since internal regions of the CH ablator are doped with Ge, mixing of this material into the hot-spot results in a clear signature of Ge K-shell emission. Evidence of jets entering the hot-spot has been recorded in x-ray images and spectra, consistent with simulation predictions [Hammel et al., High Energy Density Phys. 6, 171 (2010)]. Ignition targets have been designed to minimize instability growth, and capsule fabrication improvements are underway to reduce ''isolated defects.'' An experimental strategy has been developed where the final requirements for ignition targets can be adjusted through direct measurements of mix and experimental tuning.

Effect of perforation on the sound transmission through a double-walled cylindrical shell

Science.gov (United States)

Zhang, Qunlin; Mao, Yijun; Qi, Datong

2017-12-01

An analytical model is developed to study the sound transmission loss through a general double-walled cylindrical shell system with one or two walls perforated, which is excited by a plane wave in the presence of external mean flow. The shell motion is governed by the classical Donnell's thin shell theory, and the mean particle velocity model is employed to describe boundary conditions at interfaces between the shells and fluid media. In contrast to the conventional solid double-walled shell system, numerical results show that perforating the inner shell in the transmission side improves sound insulation performance over a wide frequency band, and removes fluctuation of sound transmission loss with frequency at mid-frequencies in the absence of external flow. Both the incidence and azimuthal angles have nearly negligible effect on the sound transmission loss over the low and middle frequency range when perforating the inner shell. Width of the frequency band with continuous sound transmission loss can be tuned by the perforation ratio.

Expert Panel Recommendations for Hanford Double-Shell Tank Life Extension

Energy Technology Data Exchange (ETDEWEB)

Stewart, Charles W; Bush, Spencer H; Berman, Herbert Stanton; Czajkowski, Carl J; Divine, James R; Posakony, Gerald J; Johnson, A B; Elmore, Monte R; Reynolds, D A; Anantatmula, Ramamohan P; Sindelar, Robert L; Zapp, Philip E

2001-06-29

Expert workshops were held in Richland in May 2001 to review the Hanford Double-Shell Tank Integrity Project and make recommendations to extend the life of Hanford's double-shell waste tanks. The workshop scope was limited to corrosion of the primary tank liner, and the main areas for review were waste chemistry control, tank inspection, and corrosion monitoring. Participants were corrosion experts from Hanford, Savannah River Site, Brookhaven National Lab., Pacific Northwest National Lab., and several consultants. This report describes the current state of the three areas of the program, the final recommendations of the workshop, and the rationale for their selection.

Laser imprint and implications for direct drive ignition with the National Ignition Facility

International Nuclear Information System (INIS)

Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Remington, B.A.; Rothenberg, J.E.

1996-01-01

For direct drive ICF, nonuniformities in laser illumination can seed ripples at the ablation front in a process called imprint. Such nonuniformities will grow during the capsule implosion and can penetrate the capsule shell impede ignition, or degrade burn. We have simulated imprint for a number of experiments on tile Nova laser. Results are in generally good agreement with experimental data. We leave also simulated imprint upon National Ignition Facility (NIF) direct drive ignition capsules. Imprint modulation amplitude comparable to the intrinsic surface finish of ∼40 nm is predicted for a laser bandwidth of 0.5 THz. Ablation front modulations experience growth factors up to several thousand, carrying modulation well into the nonlinear regime. Saturation modeling predicts that the shell should remain intact at the time of peak velocity, but penetration at earlier times appears more marginal

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT SUMMARY OF COMBINED THERMAL & OPERATING LOADS

Energy Technology Data Exchange (ETDEWEB)

MACKEY, T.C.

2006-03-17

This report summarizes the results of the Double-Shell Tank Thermal and Operating Loads Analysis (TOLA) combined with the Seismic Analysis. This combined analysis provides a thorough, defensible, and documented analysis that will become a part of the overall analysis of record for the Hanford double-shell tanks (DSTs).

Electron transport and shock ignition

Energy Technology Data Exchange (ETDEWEB)

Bell, A R; Tzoufras, M, E-mail: t.bell1@physics.ox.ac.uk [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)

2011-04-15

Inertial fusion energy (IFE) offers one possible route to commercial energy generation. In the proposed 'shock ignition' route to fusion, the target is compressed at a relatively low temperature and then ignited using high intensity laser irradiation which drives a strong converging shock into the centre of the fuel. With a series of idealized calculations we analyse the electron transport of energy into the target, which produces the pressure responsible for driving the shock. We show that transport in shock ignition lies near the boundary between ablative and heat front regimes. Moreover, simulations indicate that non-local effects are significant in the heat front regime and might lead to increased efficiency by driving the shock more effectively and reducing heat losses to the plasma corona.

A generic double-curvature piezoelectric shell energy harvester: Linear/nonlinear theory and applications

Science.gov (United States)

Zhang, X. F.; Hu, S. D.; Tzou, H. S.

2014-12-01

Converting vibration energy to useful electric energy has attracted much attention in recent years. Based on the electromechanical coupling of piezoelectricity, distributed piezoelectric zero-curvature type (e.g., beams and plates) energy harvesters have been proposed and evaluated. The objective of this study is to develop a generic linear and nonlinear piezoelectric shell energy harvesting theory based on a double-curvature shell. The generic piezoelectric shell energy harvester consists of an elastic double-curvature shell and piezoelectric patches laminated on its surface(s). With a current model in the closed-circuit condition, output voltages and energies across a resistive load are evaluated when the shell is subjected to harmonic excitations. Steady-state voltage and power outputs across the resistive load are calculated at resonance for each shell mode. The piezoelectric shell energy harvesting mechanism can be simplified to shell (e.g., cylindrical, conical, spherical, paraboloidal, etc.) and non-shell (beam, plate, ring, arch, etc.) distributed harvesters using two Lamé parameters and two curvature radii of the selected harvester geometry. To demonstrate the utility and simplification procedures, the generic linear/nonlinear shell energy harvester mechanism is simplified to three specific structures, i.e., a cantilever beam case, a circular ring case and a conical shell case. Results show the versatility of the generic linear/nonlinear shell energy harvesting mechanism and the validity of the simplification procedures.

Functions and Requirements for Automated Liquid Level Gauge Instruments in Single-Shell and Double-Shell Tank Farms

International Nuclear Information System (INIS)

CARPENTER, K.E.

1999-01-01

This functions and requirements document defines the baseline requirements and criteria for the design, purchase, fabrication, construction, installation, and operation of automated liquid level gauge instruments in the Tank Farms. This document is intended to become the technical baseline for current and future installation, operation and maintenance of automated liquid level gauges in single-shell and double-shell tank farms

Shock ignition of thermonuclear fuel: principles and modelling

International Nuclear Information System (INIS)

Atzeni, S.; Ribeyre, X.; Schurtz, G.; Schmitt, A.J.; Canaud, B.; Betti, R.; Perkins, L.J.

2014-01-01

Shock ignition is an approach to direct-drive inertial confinement fusion (ICF) in which the stages of compression and hot spot formation are partly separated. The fuel is first imploded at a lower velocity than in conventional ICF. Close to stagnation, an intense laser spike drives a strong converging shock, which contributes to hot spot formation. Shock ignition shows potentials for high gain at laser energies below 1 MJ, and could be tested on the National Ignition Facility or Laser MegaJoule. Shock ignition principles and modelling are reviewed in this paper. Target designs and computer-generated gain curves are presented and discussed. Limitations of present studies and research needs are outlined. (special topic)

Resolving a central ICF issue for ignition: Implosion symmertry

International Nuclear Information System (INIS)

Cray, M.; Delamater, N.D.; Fernandez, J.C.

1994-01-01

The Los Alamos National Laboratory Inertial Confinement Fusion (ICF) Program focuses on resolving key target-physics issues and developing technology needed for the National Ignition Facility (NIF). This work is being performed in collaboration with Lawrence Livermore National Laboratory (LLNL). A major requirement for the indirect-drive NIF ignition target is to achieve the irradiation uniformity on the capsule surface needed for a symmetrical high-convergence implosion. Los Alamos employed an integrated modeling technique using the Lasnex radiation-hydrodynamics code to design two different targets that achieve ignition and moderate gain. Los Alamos is performing experiments on the Nova Laser at LLNL in order to validate our NIF ignition calculations

Ignition of mercury-free high intensity discharge lamps

International Nuclear Information System (INIS)

Czichy, M; Mentel, J; Awakowicz, P; Hartmann, T

2008-01-01

To achieve a better understanding of the ignition behaviour of D4 lamps for automotive headlights the ignition of mercury-free metal iodide test lamps characterized by a high xenon pressure, a small electrode distance and small electrode-wall distances is investigated. The ignition of these lamps is dominated by a high voltage requirement. Nevertheless lamps are found that show a surprisingly low ignition voltage. Electrical measurements and simultaneous optical observations of the ultra-fast streamer processes show that the breakdown takes place in two different modes. One of the ignition modes which requires a high ignition voltage is characterized by a breakdown in the volume between the electrode tips. The other mode is characterized by streamer discharges along the wall. In this case the cathode, its base and the wall around is involved in the ignition process and the lamp breaks down at low voltages

A Convergent Solid-Phase Synthesis of Actinomycin Analogues - Towards Implementation of Double-Combinatorial Chemistry

DEFF Research Database (Denmark)

Tong, Glenn; Nielsen, John

1996-01-01

The actinomycin antibiotics bind to nucleic acids via both intercalation and hydrogen bonding. We found this 'double-action attack' mechanism very attractive in our search for a novel class of nucleic acid binders. A highly convergent, solid-phase synthetic strategy has been developed for a class...... with the requirements for combinatorial synthesis and furthermore, the final segment condensation allows, for the first time, double-combinatorial chemistry to be performed where two combinatorial libraries can be reacted with each other. Copyright (C) 1996 Elsevier Science Ltd....

Double Shell Tank AY-102 Radioactive Waste Leak Investigation

International Nuclear Information System (INIS)

Washenfelder, Dennis J.

2014-01-01

PowerPoint. The objectives of this presentation are to: Describe Effort to Determine Whether Tank AY-102 Leaked; Review Probable Causes of the Tank AY-102 Leak; and, Discuss Influence of Leak on Hanford's Double-Shell Tank Integrity Program

Self-template synthesis of double shelled ZnS-NiS1.97 hollow spheres for electrochemical energy storage

Science.gov (United States)

Wei, Chengzhen; Ru, Qinglong; Kang, Xiaoting; Hou, Haiyan; Cheng, Cheng; Zhang, Daojun

2018-03-01

In this work, double shelled ZnS-NiS1.97 hollow spheres have been achieved via a simple self-template route, which involves the synthesis of Zn-Ni solid spheres precursors as the self-template and then transformation into double shelled ZnS-NiS1.97 hollow spheres by sulfidation treatment. The as-prepared double shelled ZnS-NiS1.97 hollow spheres possess a high surface area (105.26 m2 g-1) and porous structures. Benefiting from the combined characteristics of novel structures, multi-component, high surface area and porous. When applied as electrode materials for supercapacitors, the double shelled ZnS-NiS1.97hollow spheres deliver a large specific capacitance of 696.8C g-1 at 5.0 A g-1 and a remarkable long lifespan cycling stability (less 5.5% loss after 6000 cycles). Moreover, an asymmetric supercapacitor (ASC) was assembled by utilizing ZnS-NiS1.97 (positive electrode) and activated carbon (negative electrode) as electrode materials. The as-assembled device possesses an energy density of 36 W h kg-1, which can be yet retained 25.6 W h kg-1 even at a power density of 2173.8 W Kg-1, indicating its promising applications in electrochemical energy storage. More importantly, the self-template route is a simple and versatile strategy for the preparation of metal sulfides electrode materials with desired structures, chemical compositions and electrochemical performances.

Cost analysis for final disposal of double-shell tank waste

International Nuclear Information System (INIS)

Seifert, T.W.; Markillie, K.D.

1996-01-01

The Cost Analysis For Final Disposal of Double-Shell Tank Waste provides the Department of Energy (DOE) and DOE contractors with a better understanding of costs associated with the transfer, storage, and treatment of liquid mixed wasted within the Double-Shell Tank System (DST). In order to evaluate waste minimization/pollution prevention ideas, it is necessary to have reliable cost data that can be used in cost/benefit analyses; preparation of funding requests and/or proposals; and provide a way for prioritizing and allocating limited resources. This cost per gallon rate will be used by DST waste generators to assess the feasibility of Pollution Prevention Opportunity Assessments (P20A) and to determine the cost avoidances or savings associated with the implementation of those P20As

Effects of turbulence enhancement on combustion process using a double injection strategy in direct-injection spark-ignition (DISI) gasoline engines

International Nuclear Information System (INIS)

Kim, Taehoon; Song, Jingeun; Park, Sungwook

2015-01-01

Highlights: • Using double injection strategy, turbulent kinetic energy can be improved with slight decrease in mixture homogeneity. • Retarded first injection timing reduces vapor fuel loss to intake port. • Double injection increases tumble intensity. • High turbulent intensity caused by double injection increases flame propagation speed. - Abstract: Direct-injection spark-ignition (DISI) gasoline engines have been spotlighted due to their high thermal efficiency. Increase in the compression ratio that result from the heat absorption effect of fuel vaporization induces higher thermal efficiency than found in port fuel injection (PFI) engines. Since fuel is injected at the cylinder directly, various fuel injection strategies can be used. In this study, turbulent intensity was improved by a double injection strategy while maintaining mixture homogeneity. To analyze the turbulence enhancement effects using the double injection strategy, a side fuel injected, homogeneous-charge-type DISI gasoline engine with a multi-hole-type injector was utilized. The spray model was evaluated using experimental data for various injection pressures and the combustion model was evaluated for varied ignition timing. First and second injection timing was swept by 20 degree interval. The turbulent kinetic energy and mixture inhomogeneity index were mapped. First injection at the middle of the intake stroke and second injection early in the compression stroke showed improved turbulent characteristics that did not significantly decrease with mixture homogeneity. A double injection case that showed improved turbulent intensity while maintaining an adequate level of mixture homogeneity and another double injection case that showed significantly improved turbulent intensity with a remarkable decrease in mixture homogeneity were considered for combustion simulation. We found that the improved turbulent intensity increased the flame propagation speed. Also, the mixture homogeneity

Enzyme-free hydrogen peroxide sensor based on Au@Ag@C core-double shell nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Li, Yancai, E-mail: liyancai@mnnu.edu.cn [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000 (China); Zhang, Yayun; Zhong, Yanmei [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Li, Shunxing [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000 (China)

2015-08-30

Graphical abstract: - Highlights: • A facile method was designed to synthesize Au@Ag@C core-double shell nanocomposites. • Carbon nanomaterials at the outermost layer could protect Au and Ag nanoparticles from oxidation and aggregation. • The Au@Ag@C core-double shell nanocomposites showed high sensitivity and selectivity to electrocatalytic reduction of hydrogen peroxide. • The hydrogen peroxide sensor has a wide linear range of 5.0 μM to 4.75 mM and a limit of detection as low as 0.14 μM. - Abstract: The well-designed Au@Ag@C core-double shell nanocomposites were synthesized via a facile method, and were used to fabricate an enzyme-free amperometric hydrogen peroxide (H{sub 2}O{sub 2}) sensor. The size, shape, elementary composition and structure of the nanocomposites were characterized by transmission electron microscope (TEM), energy-dispersed spectrum (EDS) and X-ray diffraction (XRD). The outermost layer of the nanocomposites was amorphous carbon, the second layer was Ag and the core was Au. The Au@Ag@C core-double shell nanocomposites exhibit attractive activity for electrocatalytic reduction of H{sub 2}O{sub 2} according to the electrochemical experiments. It also demonstrates the H{sub 2}O{sub 2} sensor possess well performance with a wide linear range of 5.0 μM to 4.75 mM and a limit of detection (LOD) as low as 0.14 μM (S/N = 3). Furthermore, the interference from the common interfering species, such as glucose, ascorbic acid, dopamine and uric acid can be effectively avoided. In a word, the Au@Ag@C nanocomposites are promising candidates for enzyme-free H{sub 2}O{sub 2} sensor.

Performance Requirements for the Double Shell Tank (DST) System

International Nuclear Information System (INIS)

SMITH, D.F.

2001-01-01

This document identifies the upper-level Double-Shell Tank (DST) System functions and bounds the associated performance requirements. The functions and requirements are provided along with supporting bases. These functions and requirements, in turn, will be incorporated into specifications for the DST System

Double-Shell Tank (DST) Utilities Specification

International Nuclear Information System (INIS)

SUSIENE, W.T.

2000-01-01

This specification establishes the performance requirements and provides the references to the requisite codes and standards to he applied during the design of the Double-Shell Tank (DST) Utilities Subsystems that support the first phase of waste feed delivery (WFD). The DST Utilities Subsystems provide electrical power, raw/potable water, and service/instrument air to the equipment and structures used to transfer low-activity waste (LAW) and high-level waste (HLW) to designated DST staging tanks. The DST Utilities Subsystems also support the equipment and structures used to deliver blended LAW and HLW feed from these staging tanks to the River Protection Project (RPP) Privatization Contractor facility where the waste will be immobilized. This specification is intended to be the basis for new projects/installations. This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

Analytical criterion for shock ignition of fusion reaction in hot spot

OpenAIRE

Ribeyre X.; Tikhonchuk V.T.; Breil J.; Lafon M.; Vallet A.; Bel E. Le

2013-01-01

Shock ignition of DT capsules involves two major steps. First, the fuel is assembled by means of a low velocity conventional implosion. At stagnation, the central core has a temperature lower than the one needed for ignition. Then a second, strong spherical converging shock, launched from a high intensity laser spike, arrives to the core. This shock crosses the core, rebounds at the target center and increases the central pressure to the ignition conditions. In this work we consider this latt...

The Remotely Operated Nondestructive Examination System for Examining the Knuckle Region of Hanford's Double Shell Waste Tanks

International Nuclear Information System (INIS)

Crawford, Susan L.; Pardini, Allan F.; Donald Thompson and Dale Chimenti

2005-01-01

The Pacific Northwest National Laboratory has developed a technology to address the examination requirements associated with the knuckle region of Hanford's double shell waste tanks. This examination poses a significant technical challenge because the area that requires examination is in a confined space, high radiation region and is not accessible using conventional measurement techniques. This paper describes the development, deployment, and modification of the remotely operated nondestructive examination (RONDE) system that utilizes a technique known as Synthetic Aperture Focusing (SAFT). The system detects stress corrosion cracking in the high stress region of the knuckle and characterizes the crack with tandem SAFT. PNNL has qualified the system to perform inspections on the entire knuckle region of Hanford's double shell waste tanks

Synthesis and electrochemical properties of porous double-shelled Mn2O3 hollow microspheres as a superior anode material for lithium ion batteries

International Nuclear Information System (INIS)

Qiao, Yu; Yu, Yan; Jin, Yi; Guan, Yi-Biao; Chen, Chun-Hua

2014-01-01

Highlights: • Double-shelled Mn 2 O 3 hollow microspheres are prepared by a multi-step. • synthesis procedure. • Solid, hollow and yolk-structured Mn 2 O 3 spheres are prepared for comparison. • The double-shelled hollow Mn 2 O 3 is superior in electrochemical properties. - Abstract: By means of a specially designed multi-step synthesis procedure involving steps of precipitation, controlled oxidation, selective etching and calcination, porous double-shelled Mn 2 O 3 hollow microspheres are synthesized. Solid, hollow and yolk-structured Mn 2 O 3 are also similarly synthesized for comparison. X-ray diffraction, scanning and transmission electron microscopies, IR spectroscopy, thermogravimetry, and Brunauer-Emmett-Teller measurements are employed to investigate their structures and compositions. Galvanostatic cell cycling and impedance spectroscopy are used to characterize the electrochemical properties of Mn 2 O 3 /Li cells. The results show that the hierarchical hollow structured (double-shelled, hollow and yolk-structured) Mn 2 O 3 anode materials deliver higher reversible capacities and excellent cycling stabilities than the solid Mn 2 O 3 . Moreover, among the three hierarchical hollow structured samples, the double shelled sample possesses the best cycling performance, especially at a high current density

High convergence, indirect drive inertial confinement fusion experiments at Nova

International Nuclear Information System (INIS)

Lerche, R.A.; Cable, M.D.; Hatchett, S.P.; Caird, J.A.; Kilkenny, J.D.; Kornblum, H.N.; Lane, S.M.; Laumann, C.; Murphy, T.J.; Murray, J.; Nelson, M.B.; Phillion, D.W.; Powell, H.; Ress, D.

1996-01-01

High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm 3 ; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction 2 H( 3 H,n) 4 He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x-ray images provide additional information about the implosion process. Computer models are in good agreement with measurement results. copyright 1996 American Institute of Physics

Multidimensional Analysis of Direct-Drive Plastic-Shell Implosions on OMEGA

Science.gov (United States)

Radha, P. B.

2004-11-01

Direct-drive implosions of plastic shells with the OMEGA laser are used as energy-scaled warm surrogates for ignition cryogenic targets designed for use on the National Ignition Facility. Plastic targets involve varying shell thickness (15 to 33 μm), fill pressures (3 to 15 atm), and shell adiabats. The multidimensional hydrodynamics code DRACO is used to evaluate the effects of capsule-surface roughness and illumination nonuniformities on target performance. These simulations indicate that shell stability during the acceleration phase plays a critical role in determining fusion yields. For shells that are thick enough to survive the Rayleigh--Taylor growth, target yields are significantly reduced by growth of the long (ℓ surrogacy between these plastic-shell implosions and the cryogenic ignition designs.

System Description for the Double Shell Tank (DST) Confinement System

International Nuclear Information System (INIS)

ROSSI, H.

2000-01-01

This document provides a description of the Double-Shell Tank (DST) Confinement System. This description will provide a basis for developing functional, performance and test requirements (i.e., subsystem specification), as necessary, for the DST Confinement System

L-shell dielectronic recombination for 0-like ions

International Nuclear Information System (INIS)

Omar, G.; Semedal, R.; Shahin, F.; El-Sherbini, T.H.

2007-01-01

In electron-Ion (e/I) collisions, a free electron may be captured by a positively charged ion having bound electrons with a simultaneous, excitation. This radiationless capture, most probably, creates resonance (d) states. These d- states may stabilize by emission of radiation (x-rays). This two-step process is known as Dielectronic recombination (D R). At high incident-electron energy, D R dominates over the radiative recombination (R R) and three- body recombination (Tbr) processes. Thus, D R is one of the most effective recombination for ionisation balance in solar corona and artificial plasma . In addition, the D R rates are needed for the development of nuclear fusion plasma. Thus, D R is still an interesting process m both experimental and theoretical research. Previously we have done the D R rates for 0-like AL 5+ , Cl 9+ Ti 14+ and Zn 22+ ions with K-shell excitation. In this work, the D R rates are calculated for the same ions, but with L-shell excitation. It is found that, the peak values of the D R rates for L-shell excitation are 1000 times larger than that for K-shell excitation. This means that, D R process is the most efficient mechanism for outer-shell excitations. It is found also that, the Dr rates for L-shell excitation peak at Kt = 6 Ry, 22 Ry for AL 5+ and Ti 14+ ions respectively. These Kt values are much smaller than that for for K-shell excitation

Specific features of the occurrence, development, and re-compaction of spall and shear fractures in spherically-convergent shells made of unalloyed iron and some steels under their spherical explosive loading

International Nuclear Information System (INIS)

Kozlov, E.A.; Brichikov, S.A.; Gorbachev, D.M.; Brodova, I.G.; Yablonskikh, T.I.

2007-01-01

Results of comparative metallographic examination of recovered shells exposed to explosive loading in two modes (with and without a heavy casing confining explosion products scatter) are presented. The shells were made of high-purity and technical-grade unalloyed iron with the initial grain size 250 and 125 μm, steel 30KhGSA in delivery state and quenched up to HR C 35...40, austenitic stainless steel 12Kh18N10T. The heavy casing used in experiments is demonstrated to ensure a rather compact convergence of shells destroyed at high radii. In the described comparative experiments, one managed to compile the 12Kh18N10T steel shell, after it was spalled at high radii and exposed to shear fracture and spallation layer fragmentation at medium radii, into a compact sphere but failed to do the same with the 30KhGSA quenched steel shell after it was fractured according to spall and shear mechanisms at high and medium radii. Polar zones of this steel shell have obvious undercompressed areas due to significant dissipative losses to overcome the shear strength. Occurrence, development, and re-compaction of spall and shear fractures in spherically-convergent shells made of materials, which were already carefully investigated in 1D- and 2D-geometry experiments, were systematically studied in order to verify and validate new physical models of dynamic fractures, as well as up-to-date used in 1D-, 2D- and 3D-numerical algorithms [ru

Increased Ocean Heat Convergence Into the High Latitudes With CO ₂ Doubling Enhances Polar-Amplified Warming: OCEAN HEAT AND POLAR WARMING

Energy Technology Data Exchange (ETDEWEB)

Singh, H. A. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, U.S. DOE Office of Science, Richland WA USA; Rasch, P. J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, U.S. DOE Office of Science, Richland WA USA; Rose, B. E. J. [Department of Atmospheric and Environmental Sciences, State University of New York at Albany, Albany NY USA

2017-10-18

We isolate the role of the ocean in polar climate change by directly evaluating how changes in ocean dynamics with quasi-equilibrium CO2-doubling impact high-latitude climate. With CO2-doubling, the ocean heat flux convergence (OHFC) shifts poleward in winter in both hemispheres. Imposing this pattern of perturbed OHFC in a global climate model results in a poleward shift in ocean-to-atmosphere turbulent heat fluxes (both sensible and latent) and sea ice retreat; the high-latitudes warm while the midlatitudes cool, thereby amplifying polar warming. Furthermore, midlatitude cooling is propagated to the polar mid-troposphere on isentropic surfaces, augmenting the (positive) lapse rate feedback at high latitudes. These results highlight the key role played by the partitioning of meridional energy transport changes between the atmosphere and ocean in high-latitude climate change.

Heat transfer analyses for grout disposal of radioactive double-shell slurry and customer wastes

International Nuclear Information System (INIS)

Robinson, S.M.; Gilliam, T.M.; McDaniel, E.W.

1987-04-01

Grout immobilization is being considered by Rockwell Hanford Operations (Rockwell Hanford) as a permanent disposal method for several radioactive waste streams. These include disposal of customer and double-shell slurry wastes in earthen trenches and in single-shell underground waste storage tanks. Heat transfer studies have previously been made to determine the maximum heat loading for grout disposal of various wastes under similar conditions, but a sensitivity analysis of temperature profiles to input parameters was needed. This document presents the results of heat transfer calculations for trenches containing grouted customer and double-shell slurry wastes and for in situ disposal of double-shell wastes in single-shell, domed concrete storage tanks. It discusses the conditions that lead to maximum grout temperatures of 250 0 F during the curing stage and 350 0 F thereafter and shows the dependence of these temperatures on input parameters such as soil and grout thermal conductivity, grout specific heat, waste loading, and disposal geometries. Transient heat transfer calculations were made using the HEATING6 computer code to predict temperature profiles in solidified low-level radioactive waste disposal scenarios at the Rockwell Hanford site. The calculations provide guidance for the development of safe, environmentally acceptable grout formulas for the Transportable Grout Facility. 11 refs

Flammable gas project expert elicitation results for Hanford Site double-shell tanks

International Nuclear Information System (INIS)

Bratzel, D.R.

1998-01-01

This report documents the results of the second phase of parameter quantification by the flammable gas expert panel. This second phase is focused on the analysis of flammable gas accidents in the Hanford Site double-shell tanks. The first phase of parameter quantification, performed in 1997 was focused on the analysis of Hanford single-shell tanks

Formation of NiCo{sub 2}V{sub 2}O{sub 8} yolk-double shell spheres with enhanced lithium storage properties

Energy Technology Data Exchange (ETDEWEB)

Lu, Yan; Nai, Jianwei; Lou, Xiong Wen David [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore (Singapore)

2018-03-05

Complex nanostructures with multi-components and intricate architectures hold great potential in developing high-performance electrode materials for lithium-ion batteries (LIBs). Herein, we demonstrate a facile self-templating strategy for the synthesis of metal vanadate nanomaterials with complex chemical composition of NiCo{sub 2}V{sub 2}O{sub 8} and a unique yolk-double shell structure. Starting with the Ni-Co glycerate spheres, NiCo{sub 2}V{sub 2}O{sub 8} yolk-double shell spheres are synthesized through an anion-exchange reaction of Ni-Co glycerate templates with VO{sub 3}{sup -} ions, followed by an annealing treatment. By virtue of compositional and structural advantages, these NiCo{sub 2}V{sub 2}O{sub 8} yolk-double shell spheres manifest outstanding lithium storage properties when evaluated as anodes for LIBs. Impressively, an extra-high reversible capacity of 1228 mAh g{sup -1} can be retained after 500 cycles at a high current density of 1.0 Ag{sup -1}. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

ZIF-67-derived hollow nanocages with layered double oxides shell as high-Efficiency catalysts for CO oxidation

Science.gov (United States)

Kong, Wenpeng; Li, Jing; Chen, Yao; Ren, Yuqing; Guo, Yonghua; Niu, Shengli; Yang, Yanzhao

2018-04-01

Constructing non-precious hybrid metal oxides with specific morphology as cost-effective and highly efficient catalysts is a promising way for the automotive exhaust purification. In this work, we report a facile strategy for the fabrication of a unique hollow Co-Ni layered double oxides (HLDO) nanocages by using zeolitic imidazole frameworks (ZIFs) as template. The synthesis of intermediate core-shell and hollow Co-Ni layered double hydroxides (HLDH) nanoflakes as well as the corresponding Co-Ni oxides products were successfully controlled, and the formation process was also explained. Among ZIF-67-derived oxides, HLDO exhibits excellent catalytic activities (complete conversion of CO into CO2 at 118 °C) and long-term stability for CO oxidation. The remarkable catalytic activities of HLDO can be attributed to high surface area (258 m2 g-1) inherited from the HLDH, which could provide more active sites for CO oxidation. In addition, active oxygen species indicated by the O 1 s XPS spectrum and improved synergistic effect between NiO and Co3O4 reflected by H2-TPR, further explain the enhanced performance of the HLDO catalysts. The presented strategy for controlled design and synthesis of hollow multicomponent metal oxides will provide prospects in developing highly effective catalysts.

Surface energy effect on free vibration of nano-sized piezoelectric double-shell structures

Science.gov (United States)

Fang, Xue-Qian; Zhu, Chang-Song; Liu, Jin-Xi; Liu, Xiang-Lin

2018-01-01

Combining Goldenveizer-Novozhilov shell theory, thin plate theory and electro-elastic surface theory, the size-dependent vibration of nano-sized piezoelectric double-shell structures under simply supported boundary condition is presented, and the surface energy effect on the natural frequencies is discussed. The displacement components of the cylindrical nano-shells and annular nano-plates are expanded as the superposition of standard Fourier series based on Hamilton's principle. The total stresses with consideration of surface energy effect are derived, and the total energy function is obtained by using Rayleigh-Ritz energy method. The free vibration equation is solved, and the natural frequency is analyzed. In numerical examples, it is found that the surface elastic constant, piezoelectric constant and surface residual stress show different effects on the natural frequencies. The effect of surface piezoelectric constant is the maximum. The effect of dimensions of the double-shell under different surface material properties is also examined.

Dropping the hammer: Examining impact ignition and combustion using pre-stressed aluminum powder

Science.gov (United States)

Hill, Kevin J.; Warzywoda, Juliusz; Pantoya, Michelle L.; Levitas, Valery I.

2017-09-01

Pre-stressing aluminum (Al) particles by annealing and quenching Al powder alters particle mechanical properties and has also been linked to an increase in particle reactivity. Specifically, energy propagation in composites consisting of aluminum mixed with copper oxide (Al + CuO) exhibits a 24% increase in flame speed when using pre-stressed aluminum (PS Al) compared to Al of the same particle size. However, no data exist for the reactivity of PS Al powders under impact loading. In this study, a drop weight impact tester with pressure cell was designed and built to examine impact ignition sensitivity and combustion of PS Al when mixed with CuO. Both micron and nanometer scale powders (i.e., μAl and nAl, respectively) were pre-stressed, then combined with CuO and analyzed. Three types of ignition and combustion events were identified: ignition with complete combustion, ignition with incomplete combustion, and no ignition or combustion. The PS nAl + CuO demonstrated a lower impact ignition energy threshold for complete combustion, differing from nAl + CuO samples by more than 3.5 J/mg. The PS nAl + CuO also demonstrated significantly more complete combustion as evidenced by pressure history data during ignition and combustion. Additional material characterization provides insight on hot spot formation in the incomplete combustion samples. The most probable reasons for higher impact-induced reactivity of pre-stressed particles include (a) delayed but more intense fracture of the pre-stressed alumina shell due to release of energy of internal stresses during fracture and (b) detachment of the shell from the core during impact due to high tensile stresses in the Al core leading to much more pronounced fracture of unsupported shells and easy access of oxygen to the Al core. The μAl + CuO composites did not ignite, even under pre-stressed conditions.

On sharp estimates of the convergence of double Fourier-Bessel series

Science.gov (United States)

Abilov, V. A.; Abilova, F. V.; Kerimov, M. K.

2017-11-01

The problem of approximation of a differentiable function of two variables by partial sums of a double Fourier-Bessel series is considered. Sharp estimates of the rate of convergence of the double Fourier-Bessel series on the class of differentiable functions of two variables characterized by a generalized modulus of continuity are obtained. The proofs of four theorems on this issue, which can be directly applied to solving particular problems of mathematical physics, approximation theory, etc., are presented.

Shell-like structures advanced theories and applications

CERN Document Server

Eremeyev, Victor

2017-01-01

The book presents mathematical and mechanical aspects of the theory of plates and shells, applications in civil, aero-space and mechanical engineering, as well in other areas. The focus relates to the following problems: • comprehensive review of the most popular theories of plates and shells, • relations between three-dimensional theories and two-dimensional ones, • presentation of recently developed new refined plates and shells theories (for example, the micropolar theory or gradient-type theories), • modeling of coupled effects in shells and plates related to electromagnetic and temperature fields, phase transitions, diffusion, etc., • applications in modeling of non-classical objects like, for example, nanostructures, • presentation of actual numerical tools based on the finite element approach.

Sound transmission through double cylindrical shells lined with porous material under turbulent boundary layer excitation

Science.gov (United States)

Zhou, Jie; Bhaskar, Atul; Zhang, Xin

2015-11-01

This paper investigates sound transmission through double-walled cylindrical shell lined with poroelastic material in the core, excited by pressure fluctuations due to the exterior turbulent boundary layer (TBL). Biot's model is used to describe the sound wave propagating in the porous material. Three types of constructions, bonded-bonded, bonded-unbonded and unbonded-unbonded, are considered in this study. The power spectral density (PSD) of the inner shell kinetic energy is predicted for two turbulent boundary layer models, different air gap depths and three types of polyimide foams, respectively. The peaks of the inner shell kinetic energy due to shell resonance, hydrodynamic coincidence and acoustic coincidence are discussed. The results show that if the frequency band over the ring frequency is of interest, an air gap, even if very thin, should exist between the two elastic shells for better sound insulation. And if small density foam has a high flow resistance, a superior sound insulation can still be maintained.

From harmful Microcystis blooms to multi-functional core-double-shell microsphere bio-hydrochar materials.

Science.gov (United States)

Bi, Lei; Pan, Gang

2017-11-13

Harmful algal blooms (HABs) induced by eutrophication is becoming a serious global environmental problem affecting public health and aquatic ecological sustainability. A novel strategy for the utilization of biomass from HABs was developed by converting the algae cells into hollow mesoporous bio-hydrochar microspheres via hydrothermal carbonization method. The hollow microspheres were used as microreactors and carriers for constructing CaO 2 core-mesoporous shell-CaO 2 shell microspheres (OCRMs). The CaO 2 shells could quickly increase dissolved oxygen to extremely anaerobic water in the initial 40 min until the CaO 2 shells were consumed. The mesoporous shells continued to act as regulators restricting the release of oxygen from CaO 2 cores. The oxygen-release time using OCRMs was 7 times longer than when directly using CaO 2 . More interestingly, OCRMs presented a high phosphate removal efficiency (95.6%) and prevented the pH of the solution from rising to high levels in comparison with directly adding CaO 2 due to the OH - controlled-release effect of OCRMs. The distinct core-double-shell micro/nanostructure endowed the OCRMs with triple functions for oxygen controlled-release, phosphorus removal and less impact on water pH. The study is to explore the possibility to prepare smarter bio-hydrochar materials by utilizing algal blooms.

The synthesis of Au@C@Pt core-double shell nanocomposite and its application in enzyme-free hydrogen peroxide sensing

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yayun; Li, Yuhui; Jiang, Yingying [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Li, Yancai, E-mail: liyancai@mnnu.edu.cn [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000 (China); Li, Shunxing [College of Chemistry & Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000 (China)

2016-08-15

Highlights: • A novel Au@C@Pt core-double shell nanocomposite was synthesized and characterized by SEM(*), TEM and EDS, etc. • The synthesized Au@C@Pt core-double shell nanocomposite showed high sensitivity and selectivity to electrocatalytic reduction of hydrogen peroxide (H{sub 2}O{sub 2}) and can be used to fabricate enzyme-free H{sub 2}O{sub 2} electrochemical sensor. • The H{sub 2}O{sub 2} sensor has two linear range of 9.0 μM–1.86 mM and 1.86 mM–7.11 mM, respectively, with a low limit of detection of 0.13 μM. • The H{sub 2}O{sub 2} sensor also displays high anti-interference ability, good stability and reproducibility. - Abstract: A novel Au@C@Pt core-double shell nanocomposite was synthesized and used to fabricate enzyme-free electrochemical sensor for rapid and sensitive detection of hydrogen peroxide (H{sub 2}O{sub 2}). The well-designed Au@C@Pt core-double shell nanocomposite was characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy-dispersed spectrum (EDS). The Au@C@Pt core-double shell nanocomposite modified glassy carbon electrode (Au@C@Pt/GCE) exhibits good electrocatalytic activity towards H{sub 2}O{sub 2} reduction at 0.0 V and can be used as H{sub 2}O{sub 2} sensor. The sensor displays two wide linear ranges towards H{sub 2}O{sub 2} detection. The one is 9.0 μM–1.86 mM with high sensitivity of 144.7 μA mM{sup −1} cm{sup −2}, and the other is 1.86 mM–7.11 mM with sensitivity of 80.1 μA mM{sup −1} cm{sup −2}. When signal to noise (S/N) is 3, the calculated detection limit (LOD) is 0.13 μM. Furthermore, the interference from the common interfering species such as glucose, ascorbic acid, dopamine and uric acid can be effectively avoided to H{sub 2}O{sub 2} detection. Additionally, the H{sub 2}O{sub 2} sensor also displays good stability and reproducibility.

Physics aspects of the Compact Ignition Tokamak

International Nuclear Information System (INIS)

Post, D.; Bateman, G.; Houlberg, W.

1986-11-01

The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ ∼ 2 x 10 20 sec m -3 required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k ∼ 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided

Double Shell Tank (DST) Monitor and Control Subsystem Definition Report

International Nuclear Information System (INIS)

BAFUS, R.R.

2000-01-01

The system description of the Double-Shell Tank (DST) Monitor and Control Subsystem establishes the system boundaries and describes the interface of the DST Monitor and Control Subsystem with new and existing systems that are required to accomplish the Waste Feed Delivery (WFD) mission

The experimental plan for cryogenic layered target implosions on the National Ignition Facility - The inertial confinement approach to fusion

International Nuclear Information System (INIS)

Edwards, M. J.; Lindl, J. D.; Spears, B. K.; Weber, S. V.; Atherton, L. J.; Bleuel, D. L.; Bradley, D. K.; Callahan, D. A.; Cerjan, C. J.; Clark, D; Collins, G. W.; Fair, J. E.; Fortner, R. J.; Glenzer, S. H.; Haan, S. W.; Hammel, B. A.; Hamza, A. V.; Hatchett, S. P.; Izumi, N.; Jacoby, B.

2011-01-01

Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with ρR>∼1 g/cm 2 surrounding a 10 keV hot spot with ρR ∼ 0.3 g/cm 2 . A working definition of ignition has been a yield of ∼1 MJ. At this yield the α-particle energy deposited in the fuel would have been ∼200 kJ, which is already ∼10 x more than the kinetic energy of a typical implosion. The National Ignition Campaign includes low yield implosions with dudded fuel layers to study and optimize the hydrodynamic assembly of the fuel in a diagnostics rich environment. The fuel is a mixture of tritium-hydrogen-deuterium (THD) with a density equivalent to DT. The fraction of D can be adjusted to control the neutron yield. Yields of ∼10 14-15 14 MeV (primary) neutrons are adequate to diagnose the hot spot as well as the dense fuel properties via down scattering of the primary neutrons. X-ray imaging diagnostics can function in this low yield environment providing additional information about the assembled fuel either by imaging the photons emitted by the hot central plasma, or by active probing of the dense shell by a separate high energy short pulse flash. The planned use of these targets and diagnostics to assess and optimize the assembly of the fuel and how this relates to the predicted performance of DT targets is described. It is found that a good predictor of DT target performance is the THD measurable parameter, Experimental Ignition Threshold Factor, ITFX ∼ Y x dsf 2.3 , where Y is the measured neutron yield between 13 and 15 MeV, and dsf is the down scattered neutron fraction defined as the ratio of neutrons between 10 and 12 MeV and those between 13 and 15 MeV.

Retrieval technology development for Hanford double-shell tanks

International Nuclear Information System (INIS)

Bamberger, J.A.; Wise, B.M.; Miller, W.C.

1992-05-01

This paper describes the combined analytical, computational, and experimental program developed for identifying operating strategies for mobilization and retrieval of radioactive waste stored in double-shell tanks at Hanford. Sludge mobilization, slurry uniformity, and slurry retrieval investigations will produce guidelines for mixer pump and retrieval pump operation based on the physical properties of the waste and the geometric properties of the system (number of operating pumps and pump design and placement)

Facile synthesis of mercaptosuccinic acid-capped CdTe/CdS/ZnS core/double shell quantum dots with improved cell viability on different cancer cells and normal cells

Energy Technology Data Exchange (ETDEWEB)

Parani, Sundararajan [University of Madras, Department of Inorganic Chemistry (India); Bupesh, Giridharan [Bharath University, Central Research Laboratory, Sree Balaji Medical College and Hospital (India); Manikandan, Elayaperumal [Thiruvalluvar University, Department of Physics, TUCAS, Thennangur-604408 (India); Pandian, Kannaiyan [University of Madras, Department of Inorganic Chemistry (India); Oluwafemi, Oluwatobi Samuel, E-mail: oluwafemi.oluwatobi@gmail.com [University of Johannesburg, Department of Applied Chemistry (South Africa)

2016-11-15

Water-soluble, mercaptosuccinic acid (MSA)-capped CdTe/CdS/ZnS core/double shell quantum dots (QDs) were prepared by successive growth of CdS and ZnS shells on the as-synthesized CdTe/CdS{sub thin} core/shell quantum dots. The formation of core/double shell structured QDs was investigated by ultraviolet-visible (UV–Vis) absorption and photoluminescence (PL) spectroscopy, PL decay studies, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The core/double shell QDs exhibited good photoluminescence quantum yield (PLQY) which is 70% higher than that of the parent core/shell QDs, and they are stable for months. The average particle size of the core/double shell QDs was ∼3 nm as calculated from the transmission electron microscope (TEM) images. The cytotoxicity of the QDs was evaluated on a variety of cancer cells such as HeLa, MCF-7, A549, and normal Vero cells by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell viability assay. The results showed that core/double shell QDs were less toxic to the cells when compared to the parent core/shell QDs. MCF-7 cells showed proliferation on incubation with QDs, and this is attributed to the metalloestrogenic activity of cadmium ions released from QDs. The core/double shell CdTe/CdS/ZnS (CSS) QDs were conjugated with transferrin and successfully employed for the biolabeling and fluorescent imaging of HeLa cells. These core/double shell QDs are highly promising fluorescent probe for cancer cell labeling and imaging applications.

Prediction of Ignition of High Explosive When Submitted To Impact

Science.gov (United States)

Picart, Didier; Delmaire-Sizes, Franck; Gruau, Cyril; Trumel, Herve

2009-06-01

High explosive structures may unintentionally ignite and transit to deflagration or detonation, when subjected to mechanical loadings, such as low velocity impact. We focus our attention on ignition. The Browning and Scammon [1] criterion has been adapted. A concrete like constitutive law is derived, with an up-to-date experimental characterization. These models have been implemented in Abaqus/Explicit [2]. Numerical simulations are used to calibrate the ignition threshold. The presentation or the poster will detail the main assumptions, the models (Browning et al, mechanical behavior) and the calibration procedure. Comparisons between numerical results and experiments [3] will show the interest of this method but also its limitations (numerical artifacts, lack of mechanical data, misinterpretation of reactive tests). [1] R. Browning and R. Scammon, Shock compression of condensed matter, pp. 987-990, (2001). [2] C. Gruau, D. Picart et al., 17^th Dymat technical meeting, Cambridge, UK, (2007). [3] F. Delmaire-Sizes et al., 3^rd International symposium on energetic materials, Tokyo, Japan, (2008).

Controlled-release and preserved bioactivity of proteins from (self-assembled core-shell double-walled microspheres

Directory of Open Access Journals (Sweden)

Yuan W

2012-01-01

Full Text Available Weien Yuan1,2, Zhenguo Liu11Department of Neurology, Xinhua Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: In order to address preserved protein bioactivities and protein sustained-release problems, a method for preparing double-walled microspheres with a core (protein-loaded nanoparticles with a polymer-suspended granule system-formed core and a second shell (a polymer-formed shell for controlled drug release and preserved protein bioactivities has been developed using (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W phases. The method, based on our previous microsphere preparation method (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W, employs different concentric poly(D,L-lactide-co-glycolide, poly(D,L-lactide, and protein-loaded nanoparticles to produce a suspended liquid which then self-assembles to form shell-core microspheres in the hydrophilic oil phase, which are then solidified in the water phase. Variations in the preparation parameters allowed complete encapsulation by the shell phase, including the efficient formation of a poly(D,L-lactide shell encapsulating a protein-loaded nanoparticle-based poly(D,L-lactide-co-glycolide core. This method produces core-shell double-walled microspheres that show controlled protein release and preserved protein bioactivities for 60 days. Based upon these results, we concluded that the core-shell double-walled microspheres might be applied for tissue engineering and therapy for chronic diseases, etc.Keywords: protein delivery, protein stability, core-shell microspheres, dextran nanoparticles

Diagnosing ignition with DT reaction history

International Nuclear Information System (INIS)

Wilson, D. C.; Bradley, P. A.; Herrmann, H. W.; Cerjan, C. J.; Salmonson, J. D.; Spears, B. K.; Hatchet, S. P. II; Glebov, V. Yu.

2008-01-01

A full range DT reaction history of an ignition capsule, from 10 9 to 10 20 neutrons/ns, offers the opportunity to diagnose fuel conditions hundreds of picoseconds before and during burn. The burn history begins with a sharp rise when the first shock reaches the center of the capsule. The level of this jump reflects the combined shock strength and the adiabat of DT fuel. Changes to the four laser pulses driving the capsule implosion which are large enough to degrade the yield make measurable changes to the reaction history. Low mode asymmetries grow during convergence but change the reaction history during the final ∼100 ps. High mode asymmetry or turbulence mixing affects only the reaction history within ∼50 ps of peak burn rate. A capsule with a tritium fuel layer containing a small amount of deuterium (∼1%) creates a reaction history similar to the ignition capsule, but without the final ignition burn. A combination of gas Cerenkov detectors and the neutron temporal diagnostic could be capable of diagnosing the full history of ignition and tritium rich capsules.

Analysis Bounding Double Shell Tank (DST) Performance for the Hanford Tank Waste Operation Simulator Case 2

International Nuclear Information System (INIS)

SMITH, D.F.

2002-01-01

The purpose of this analysis is to compare the latest Tank Farm Contractor Operation and Utilization Plan (HNF-SD-WM-SP-012, Rev. 3) ''Case 2'' operating scenarios with a previous bounding analysis for the Double-Shell Tank (DST) System in order to provide a technical assessment against the current set of DST System performance requirements. A later update to HNF-SD-WM-SP-012 (i.e., Rev. 3A), released in late December 2001, did not impact the results of this analysis. This analysis provides technical support for revising the Performance Requirements for the Double-Shell Tank System, HNF-2168, Rev. 3, used as the basis for defining performance requirements noted in System Specification for the Double-Shell Tank System, HNF-SD-WM-TRD-007. Rev. 1

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT SEISMIC ANALYSIS OF HANFORD DOUBLE SHELL TANKS

Energy Technology Data Exchange (ETDEWEB)

MACKEY, T.C.

2006-03-17

M&D Professional Services, Inc. (M&D) is under subcontract to Pacific Northwest National Laboratory (PNNL) to perform seismic analysis of the Hanford Site double-shell tanks (DSTs) in support of a project entitled ''Double-Shell Tank (DSV Integrity Project--DST Thermal and Seismic Analyses)''. The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the DST system at Hanford in support of Tri-Party Agreement Milestone M-48-14, The work described herein was performed in support of the seismic analysis of the DSTs. The thermal and operating loads analysis of the DSTs is documented in Rinker et al. (2004). The work statement provided to M&D (PNNL 2003) required that the seismic analysis of the DSTs assess the impacts of potentially non-conservative assumptions in previous analyses and account for the additional soil mass due to the as-found soil density increase, the effects of material degradation, additional thermal profiles applied to the full structure including the soil-structure response with the footings, the non-rigid (low frequency) response of the tank roof, the asymmetric seismic-induced soil loading, the structural discontinuity between the concrete tank wall and the support footing and the sloshing of the tank waste. The seismic analysis considers the interaction of the tank with the surrounding soil and the effects of the primary tank contents. The DSTs and the surrounding soil are modeled as a system of finite elements. The depth and width of the soil incorporated into the analysis model are sufficient to obtain appropriately accurate analytical results. The analyses required to support the work statement differ from previous analysis of the DSTs in that the soil-structure interaction (SSI) model includes several (nonlinear) contact surfaces in the tank structure, and the contained waste must be modeled explicitly in order to capture the fluid-structure interaction behavior between the primary

The high-foot implosion campaign on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Hurricane, O. A., E-mail: hurricane1@llnl.gov; Callahan, D. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Barrios Garcia, M. A.; Hinkel, D. E.; Berzak Hopkins, L. F.; Kervin, P.; Pape, S. Le; Ma, T.; MacPhee, A. G.; Milovich, J. L.; Moody, J.; Pak, A. E.; Patel, P. K.; Park, H.-S.; Remington, B. A.; Robey, H. F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); and others

2014-05-15

The “High-Foot” platform manipulates the laser pulse-shape coming from the National Ignition Facility laser to create an indirect drive 3-shock implosion that is significantly more robust against instability growth involving the ablator and also modestly reduces implosion convergence ratio. This strategy gives up on theoretical high-gain in an inertial confinement fusion implosion in order to obtain better control of the implosion and bring experimental performance in-line with calculated performance, yet keeps the absolute capsule performance relatively high. In this paper, we will cover the various experimental and theoretical motivations for the high-foot drive as well as cover the experimental results that have come out of the high-foot experimental campaign. At the time of this writing, the high-foot implosion has demonstrated record total deuterium-tritium yields (9.3×10{sup 15}) with low levels of inferred mix, excellent agreement with implosion simulations, fuel energy gains exceeding unity, and evidence for the “bootstrapping” associated with alpha-particle self-heating.

Horizon shells and BMS-like soldering transformations

Energy Technology Data Exchange (ETDEWEB)

Blau, Matthias [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); O’Loughlin, Martin [University of Nova Gorica,Vipavska 13, 5000 Nova Gorica (Slovenia)

2016-03-07

We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.

A new metric of the low-mode asymmetry for ignition target designs

International Nuclear Information System (INIS)

Gu, Jianfa; Dai, Zhensheng; Fan, Zhengfeng; Zou, Shiyang; Ye, Wenhua; Pei, Wenbing; Zhu, Shaoping

2014-01-01

In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the measured neutron yield and hot spot pressure are significantly lower than simulations. Understanding the underlying physics of the deficit is essential to achieving ignition. This paper investigates the low-mode areal density asymmetry in the main fuel of ignition capsule. It is shown that the areal density asymmetry breaks up the compressed shell and significantly reduces the conversion of implosion kinetic energy to hot spot internal energy, leading to the calculated hot spot pressure and neutron yield quite close to the experimental data. This indicates that the low-mode shell areal density asymmetry can explain part of the large discrepancy between simulations and experiments. Since only using the hot spot shape term could not adequately characterize the effects of the shell areal density asymmetry on implosion performance, a new metric of the low-mode asymmetry is developed to accurately measure the probability of ignition

Target Visualization at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Potter, Daniel Abraham [Univ. of California, Davis, CA (United States)

2011-01-01

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.

Double-Shell Tank (DST) Monitor and Control Subsystem Specification

International Nuclear Information System (INIS)

BAFUS, R.R.

2000-01-01

This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied during design of the Double-Shell Tank (DST) Monitor and Control Subsystem that supports the first phase of Waste Feed Delivery. This subsystem specification establishes the interface and performance requirements and provides references to the requisite codes and standards to be applied during the design of the Double-Shell Tank (DST) Monitor and Control Subsystem. The DST Monitor and Control Subsystem consists of the new and existing equipment that will be used to provide tank farm operators with integrated local monitoring and control of the DST systems to support Waste Feed Delivery (WFD). New equipment will provide automatic control and safety interlocks where required and provide operators with visibility into the status of DST subsystem operations (e.g., DST mixer pump operation and DST waste transfers) and the ability to manually control specified DST functions as necessary. This specification is intended to be the basis for new project/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

Laser-plasma interaction physics for shock ignition

Directory of Open Access Journals (Sweden)

Goyon C.

2013-11-01

Full Text Available In the shock ignition scheme, the ICF target is first compressed with a long (nanosecond pulse before creating a convergent shock with a short (∼100 ps pulse to ignite thermonuclear reactions. This short pulse is typically (∼2.1015–1016 W/cm2 above LPI (Laser Plasma Instabilities thresholds. The plasma is in a regime where the electron temperature is expected to be very high (2–4 keV and the laser coupling to the plasma is not well understood. Emulating LPI in the corona requires large and hot plasmas produced by high-energy lasers. We conducted experiments on the LIL (Ligne d'Integration Laser, 10 kJ at 3ω and the LULI2000 (0.4 kJ at 2ω facilities, to approach these conditions and study absorption and LPI produced by a high intensity beam in preformed plasmas. After introducing the main risks associated with the short pulse propagation, we present the latest experiment we conducted on LPI in relevant conditions for shock ignition.

Sandwich-like graphene/polypyrrole/layered double hydroxide nanowires for high-performance supercapacitors

Science.gov (United States)

Li, Xuejin; Zhang, Yu; Xing, Wei; Li, Li; Xue, Qingzhong; Yan, Zifeng

2016-11-01

Electrode design in nanoscale is considered to be ultra-important to construct a superb capacitor. Herein, a sandwich-like composite was made by combining graphene/polypyrrole (GPPY) with nickel-aluminum layered double hydroxide nanowires (NiAl-NWs) via a facile hydrothermal method. This sandwich-like architecture is promising in energy storage applications due to three unique features: (1) the conductive GPPY substrate not only effectively prevents the layered double hydroxides species from aggregating, but also considerably facilitates the electron transmission; (2) the ultrathin NiAl-NWs ensure a maximum exposure of active Ni2+, which can improve the efficiency of rapid redox reactions even at high current densities; (3) the sufficient space between anisotropic NiAl-NWs can accommodate a large volume change of the nanowires to avoid their collapse or distortion during the reduplicative redox reactions. Keeping all these unique features in mind, when the as-prepared composite was applied to supercapacitors, it presented an enhanced capacitive performance in terms of high specific capacitance (845 F g-1), excellent rate performance (67% retained at 30 A g-1), remarkable cyclic stability (92% maintained after 5000 cycles) and large energy density (40.1 Wh·Kg-1). This accomplishment in the present work inspires an innovative strategy of nanoscale electrode design for high-rate performance supercapacitor electrodes containing pseuducapacitive metal oxide.

Isochoric Implosions for Fast Ignition

International Nuclear Information System (INIS)

Clark, D S; Tabak, M

2007-01-01

Various gain models have shown the potentially great advantages of Fast Ignition (FI) Inertial Confinement Fusion (ICF) over its conventional hot spot ignition counterpart [e.g., S. Atzeni, Phys. Plasmas 6, 3316 (1999); M. Tabak et al., Fusion Sci. and Technology 49, 254 (2006)]. These gain models, however, all assume nearly uniform-density fuel assemblies. In contrast, conventional ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pressure hot spot. Hence, to realize fully the advantages of FI, an alternative implosion design must be found which yields nearly isochoric fuel assemblies without substantial hot spots. Here, it is shown that a self-similar spherical implosion of the type originally studied by Guderley [Luftfahrtforschung 19, 302 (1942)] may be employed to yield precisely such quasi-isochoric imploded states. The difficulty remains, however, of accessing these self-similarly imploding configurations from initial conditions representing an actual ICF target, namely a uniform, solid-density shell at rest. Furthermore, these specialized implosions must be realized for practicable drive parameters and at the scales and energies of interest in ICF. A direct-drive implosion scheme is presented which meets all of these requirements and reaches a nearly isochoric assembled density of 300 g=cm 3 and areal density of 2.4 g=cm 2 using 485 kJ of laser energy

Applications and results of X-ray spectroscopy in implosion experiments on the National Ignition Facility

Science.gov (United States)

Epstein, R.; Regan, S. P.; Hammel, B. A.; Suter, L. J.; Scott, H. A.; Barrios, M. A.; Bradley, D. K.; Callahan, D. A.; Cerjan, C.; Collins, G. W.; Dixit, S. N.; Döppner, T.; Edwards, M. J.; Farley, D. R.; Fournier, K. B.; Glenn, S.; Glenzer, S. H.; Golovkin, I. E.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Key, M. H.; Kilkenny, J. D.; Kline, J. L.; Kyrala, G. A.; Landen, O. L.; Ma, T.; MacFarlane, J. J.; Mackinnon, A. J.; Mancini, R. C.; McCrory, R. L.; Meyerhofer, D. D.; Meezan, N. B.; Nikroo, A.; Park, H.-S.; Patel, P. K.; Ralph, J. E.; Remington, B. A.; Sangster, T. C.; Smalyuk, V. A.; Springer, P. T.; Town, R. P. J.; Tucker, J. L.

2017-03-01

Current inertial confinement fusion experiments on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] are attempting to demonstrate thermonuclear ignition using x-ray drive by imploding spherical targets containing hydrogen-isotope fuel in the form of a thin cryogenic layer surrounding a central volume of fuel vapor [J. Lindl, Phys. Plasmas 2, 3933 (1995)]. The fuel is contained within a plastic ablator layer with small concentrations of one or more mid-Z elements, e.g., Ge or Cu. The capsule implodes, driven by intense x-ray emission from the inner surface of a hohlraum enclosure irradiated by the NIF laser, and fusion reactions occur in the central hot spot near the time of peak compression. Ignition will occur if the hot spot within the compressed fuel layer attains a high-enough areal density to retain enough of the reaction product energy to reach nuclear reaction temperatures within the inertial hydrodynamic disassembly time of the fuel mass [J. Lindl, Phys. Plasmas 2, 3933 (1995)]. The primary purpose of the ablator dopants is to shield the ablator surface adjacent to the DT ice from heating by the hohlraum x-ray drive [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]. Simulations predicted that these dopants would produce characteristic K-shell emission if ablator material mixed into the hot spot [B. A. Hammel et al., High Energy Density Phys. 6, 171 (2010)]. In NIF ignition experiments, emission and absorption features from these dopants appear in x-ray spectra measured with the hot-spot x-ray spectrometer in Supersnout II [S. P. Regan et al., "Hot-Spot X-Ray Spectrometer for the National Ignition Facility," to be submitted to Review of Scientific Instruments]. These include K-shell emission lines from the hot spot (driven primarily by inner-shell collisional ionization and dielectronic recombination) and photoionization edges, fluorescence, and absorption lines caused by the absorption of the

Studies on the robustness of shock-ignited laser fusion targets

International Nuclear Information System (INIS)

Atzeni, S; Schiavi, A; Marocchino, A

2011-01-01

Several aspects of the sensitivity of a shock-ignited inertial fusion target to variation of parameters and errors or imperfections are studied by means of one-dimensional and two-dimensional numerical simulations. The study refers to a simple all-DT target, initially proposed for fast ignition (Atzeni et al 2007 Phys. Plasmas 7 052702) and subsequently shown to be also suitable for shock ignition (Ribeyre et al 2009 Plasma Phys. Control. Fusion 51 015013). It is shown that the growth of both Richtmyer-Meshkov and Rayleigh-Taylor instability (RTI) at the ablation front is reduced by laser pulses with an adiabat-shaping picket. An operating window for the parameters of the ignition laser spike is described; the threshold power depends on beam focusing and synchronization with the compression pulse. The time window for spike launch widens with beam power, while the minimum spike energy is independent of spike power. A large parametric scan indicates good tolerance (at the level of a few percent) to target mass and laser power errors. 2D simulations indicate that the strong igniting shock wave plays an important role in reducing deceleration-phase RTI growth. Instead, the high hot-spot convergence ratio (ratio of initial target radius to hot-spot radius at ignition) makes ignition highly sensitive to target mispositioning.

DOUBLE-SHELL TANK WASTE TRANSFER LINE ENCASEMENT INTEGRITY ASSESSMENT TECHNOLOGY STUDY

International Nuclear Information System (INIS)

BOWER, R.R.

2006-01-01

The report provides various alternative methods of performing integrity assessment inspections of buried Hanford Double Shell Tank waste transfer line encasements, and provides method recommendations as an alternative to costly encasement pneumatic leak testing. A schedule for future encasement integrity assessments is also included

Double-shelled silicon anode nanocomposite materials: A facile approach for stabilizing electrochemical performance via interface construction

Science.gov (United States)

Du, Lulu; Wen, Zhongsheng; Wang, Guanqin; Yang, Yan-E.

2018-04-01

The rapid capacity fading induced by volumetric changes is the main issue that hinders the widespread application of silicon anode materials. Thus, double-shelled silicon composite materials where lithium silicate was located between an Nb2O5 coating layer and a silicon active core were configured to overcome the chemical compatibility issues related to silicon and oxides. The proposed composites were prepared via a facile co-precipitation method combined with calcination. Transmission electron microscopy and X-ray photoelectron spectroscopy analysis demonstrated that a transition layer of lithium silicate was constructed successfully, which effectively hindered the thermal inter-diffusion between the silicon and oxide coating layers during heat treatment. The electrochemical performance of the double-shelled silicon composites was enhanced dramatically with a retained specific capacity of 1030 mAh g-1 after 200 cycles at a current density of 200 mA g-1 compared with 598 mAh g-1 for a core-shell Si@Nb2O5 composite that lacked the interface. The lithium silicate transition layer was shown to play an important role in maintaining the high electrochemical stability.

Piezo-phototronic effect enhanced UV photodetector based on CuI/ZnO double-shell grown on flexible copper microwire.

Science.gov (United States)

Liu, Jingyu; Zhang, Yang; Liu, Caihong; Peng, Mingzeng; Yu, Aifang; Kou, Jinzong; Liu, Wei; Zhai, Junyi; Liu, Juan

2016-12-01

In this work, we present a facile, low-cost, and effective approach to fabricate the UV photodetector with a CuI/ZnO double-shell nanostructure which was grown on common copper microwire. The enhanced performances of Cu/CuI/ZnO core/double-shell microwire photodetector resulted from the formation of heterojunction. Benefiting from the piezo-phototronic effect, the presentation of piezocharges can lower the barrier height and facilitate the charge transport across heterojunction. The photosensing abilities of the Cu/CuI/ZnO core/double-shell microwire detector are investigated under different UV light densities and strain conditions. We demonstrate the I-V characteristic of the as-prepared core/double-shell device; it is quite sensitive to applied strain, which indicates that the piezo-phototronic effect plays an essential role in facilitating charge carrier transport across the CuI/ZnO heterojunction, then the performance of the device is further boosted under external strain.

Shell-like configuration in O+ ion velocity distribution at high altitudes in the dayside magnetosphere observed by Cluster/CIS

Directory of Open Access Journals (Sweden)

S. Joko

2004-07-01

Full Text Available We report shell-like configurations seen in O+ ion velocity distributions. One case was observed above 8RE in radial distance in the dayside magnetosphere, presumably in the mantle region, during the observation period of 09:30-10:00 UT on 12 April 2001 by the CIS instrument on board the Cluster satellite. This shell-like configuration was different from so-called "conics" or "beams": the lower energy (cold population and the higher energy partial shell part were seen together, but there was no obvious signature of heating process. With respect to H+ ion velocity distributions observed simultaneously, transverse heating (so-called in "pan-cake" shape or field-aligned energisation configurations were seen as the result of heating/energisation processes and the upward-going part of the distribution also formed a half spherical thick shell configuration. Concerning O+ ion heating in the case of 12 April 2001, it was obviously observed when the spacecraft passed through the mantle region close to the poleward cusp. As the spacecraft moved toward the dayside cusp shell-like (or dome shape velocity distributions appeared apparently and continued to be observed until the spacecraft reached the magnetopause according to two other different cases (13 February 2001 and 14 April 2001. Two other cases were observed in the Southern Hemisphere and the spacecraft was supposed to pass through the dayside cusp toward the mantle region at higher altitudes (9-11RE. O+ ion velocity distributions in these cases show pre-/post-structured shell-like configurations, depending on the observation sites (mantle or dayside cusp.

X-ray backlighting requirements for the double-shell target

International Nuclear Information System (INIS)

Larsen, J.T.

1980-01-01

We have analyzed one specific NOVA double-shell target design and have determined the x-ray energies required for probing the performance of the implosion. It is virtually impossible to study the compression of the fuel or the motion of the inner pusher. An x-ray energy of about 9 keV appears to be ideal for measuring the behavior of the outer TaCOH shell for the majority of its travel. However, it would be advantageous to have an x-ray source of about 25 keV to measure the contact between the two shells. Development of narrowband x-ray line sources are more desirable than broadband continuum sources since the intensity per keV is many times greater in the line. Intensities of the probes are determined by the self-emission levels of the target capsule. For the 9 keV line source, an intensity of upwards to 10 15 keV/keV/sh/cm 2 /sr is required with a source area of about 0.01 cm 2

Polar-Drive Experiments at the National Ignition Facility

Science.gov (United States)

Hohenberger, M.

2014-10-01

To support direct-drive inertial confinement fusion (ICF) experiments at the National Ignition Facility (NIF) in its indirect-drive beam configuration, the polar-drive (PD) concept has been proposed. It requires direct-drive-specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments testing the performance of ignition-relevant PD implosions at the NIF have been performed. The goal of these early experiments was to develop a stable, warm implosion platform to investigate laser deposition and laser-plasma instabilities at ignition-relevant plasma conditions, and to develop and validate ignition-relevant models of laser deposition and heat conduction. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Warm, 2.2-mm-diam plastic shells were imploded with total drive energies ranging from ~ 350 to 750 kJ with peak powers of 60 to 180 TW and peak on-target intensities from 4 ×1014 to 1 . 2 ×1015 W/cm2. Results from these initial experiments are presented, including the level of hot-electron preheat, and implosion symmetry and shell trajectory inferred via self-emission imaging and backlighting. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray trace to model oblique beams, and a model for cross-beam energy transfer (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Recent experimental results on ICF target implosions by Z-pinch radiation sources and their relevance to ICF ignition studies

International Nuclear Information System (INIS)

Mehlhorn, T A; Bailey, J E; Bennett, G; Chandler, G A; Cooper, G; Cuneo, M E; Golovkin, I; Hanson, D L; Leeper, R J; MacFarlane, J J; Mancini, R C; Matzen, M K; Nash, T J; Olson, C L; Porter, J L; Ruiz, C L; Schroen, D G; Slutz, S A; Varnum, W; Vesey, R A

2003-01-01

Inertial confinement fusion capsule implosions absorbing up to 35 kJ of x-rays from a ∼220 eV dynamic hohlraum on the Z accelerator at Sandia National Laboratories have produced thermonuclear D-D neutron yields of (2.6±1.3) x 10 10 . Argon spectra confirm a hot fuel with T e ∼ 1 keV and n e ∼ (1-2) x 10 23 cm -3 . Higher performance implosions will require radiation symmetry control improvements. Capsule implosions in a ∼70 eV double-Z-pinch-driven secondary hohlraum have been radiographed by 6.7 keV x-rays produced by the Z-beamlet laser (ZBL), demonstrating a drive symmetry of about 3% and control of P 2 radiation asymmetries to ±2%. Hemispherical capsule implosions have also been radiographed in Z in preparation for future experiments in fast ignition physics. Z-pinch-driven inertial fusion energy concepts are being developed. The refurbished Z machine (ZR) will begin providing scaling information on capsule and Z-pinch in 2006. The addition of a short pulse capability to ZBL will enable research into fast ignition physics in the combination of ZR and ZBL-petawatt. ZR could provide a test bed to study NIF-relevant double-shell ignition concepts using dynamic hohlraums and advanced symmetry control techniques in the double-pinch hohlraum backlit by ZBL

Recent experimental results on ICF target implosions by Z-pinch radiation sources and their relevance to ICF ignition studies

International Nuclear Information System (INIS)

Bailey, James E.; Chandler, Gordon Andrew; Vesey, Roger Alan; Hanson, David Lester; Olson, Craig Lee; Nash, Thomas J.; Matzen, Maurice Keith; Ruiz, Carlos L.; Porter, John Larry Jr.; Cuneo, Michael Edward; Varnum, William S.; Bennett, Guy R.; Cooper, Gary Wayne; Schroen, Diana Grace; Slutz, Stephen A.; MacFarlane, Joseph John; Leeper, Ramon Joe; Golovkin, I.E.; Mehlhorn, Thomas Alan; Mancini, Roberto Claudio

2003-01-01

Inertial confinement fusion capsule implosions absorbing up to 35 kJ of x-rays from a ∼220 eV dynamic hohlraum on the Z accelerator at Sandia National Laboratories have produced thermonuclear D-D neutron yields of (2.6 ± 1.3) x 10 10 . Argon spectra confirm a hot fuel with Te ∼ 1 keV and n e ∼ (1-2) x 10 23 cm -3 . Higher performance implosions will require radiation symmetry control improvements. Capsule implosions in a ∼70 eV double-Z-pinch-driven secondary hohlraum have been radiographed by 6.7 keV x-rays produced by the Z-beamlet laser (ZBL), demonstrating a drive symmetry of about 3% and control of P 2 radiation asymmetries to ±2%. Hemispherical capsule implosions have also been radiographed in Z in preparation for future experiments in fast ignition physics. Z-pinch-driven inertial fusion energy concepts are being developed. The refurbished Z machine (ZR) will begin providing scaling information on capsule and Z-pinch in 2006. The addition of a short pulse capability to ZBL will enable research into fast ignition physics in the combination of ZR and ZBL-petawatt. ZR could provide a test bed to study NIF-relevant double-shell ignition concepts using dynamic hohlraums and advanced symmetry control techniques in the double-pinch hohlraum backlit by ZBL.

Shock wave focusing in water inside convergent structures

Directory of Open Access Journals (Sweden)

C Wang

2016-09-01

Full Text Available Experiments on shock focusing in water-filled convergent structures have been performed. A shock wave in water is generated by means of a projectile, launched from a gas gun, which impacts a water-filled convergent structure. Two types of structures have been tested; a bulk material and a thin shell structure. The geometric shape of the convergent structures is given by a logarithmic spiral, and this particular shape is chosen because it maximizes the amount of energy reaching the focal region. High-speed schlieren photography is used to visualize the shock dynamics during the focusing event. Results show that the fluid-structure interaction between the thin shell structure and the shock wave in the water is different from that of a bulk structure; multiple reflections of the shock wave inside the thin shell are reflected back into the water, thus creating a wave train, which is not observed for shock focusing in a bulk material.

Magnetite and magnetite/silver core/shell nanoparticles with diluted magnet-like behavior

International Nuclear Information System (INIS)

Garza-Navarro, Marco; Torres-Castro, Alejandro; Gonzalez, Virgilio; Ortiz, Ubaldo; De la Rosa, Elder

2010-01-01

In the present work is reported the use of the biopolymer chitosan as template for the preparation of magnetite and magnetite/silver core/shell nanoparticles systems, following a two step procedure of magnetite nanoparticles in situ precipitation and subsequent silver ions reduction. The crystalline and morphological characteristics of both magnetite and magnetite/silver core/shell nanoparticles systems were analyzed by high resolution transmission electron microscopy (HRTEM) and nanobeam diffraction patterns (NBD). The results of these studies corroborate the core/shell morphology and the crystalline structure of the magnetite core and the silver shell. Moreover, magnetization temperature dependent, M(T), measurements show an unusual diluted magnetic behavior attributed to the dilution of the magnetic ordering in the magnetite and magnetite/silver core/shell nanoparticles systems. - Graphical abstract: Biopolymer chitosan was used as stabilization media to synthesize both magnetite and magnetite/silver core/shell nanoparticles. Results of HRTEM and NBD patterns confirm core/shell morphology of the obtained nanoparticles. It was found that the composites show diluted magnet-like behavior.

Features of a point design for Fast Ignition

International Nuclear Information System (INIS)

Tabak, M; Clark, D; Town, R P J; Key, M H; Amendt, P; Ho, D; Meeker, D J; Shay, H D; Lasinski, B F; Kemp, A; Divol, L; Mackinnon, A J; Patel, P; Strozzi, D; Grote, D P

2010-01-01

Fast Ignition is an inertial fusion scheme in which fuel is first assembled and then heated to the ignition temperature with an external heating source. In this note we consider cone and shell implosions where the energy supplied by short pulse lasers is transported to the fuel by electrons. We describe possible failure modes for this scheme and how to overcome them. In particular, we describe two sources of cone tip failure, an axis jet driven from the compressed fuel mass and hard photon preheat leaking through the implosion shell, and laser prepulse that can change the position of laser absorption and the angular distribution of the emitted electrons.

Features of a point design for fast ignition

International Nuclear Information System (INIS)

Tabak, M.; Clark, D.; Town, R.J.; Key, M.H.; Amendt, P.; Ho, D.; Meeker, D.J.; Shay, H.D.; Lasinski, B.F.; Kemp, A.; Divol, L.; Mackinnon, A.J.; Patel, P.; Strozzi, D.; Grote, D.P.

2009-01-01

Fast Ignition is an inertial fusion scheme in which fuel is first assembled and then heated to the ignition temperature with an external heating source. In this note we consider cone and shell implosions where the energy supplied by short pulse lasers is transported to the fuel by electrons. We describe possible failure modes for this scheme and how to overcome them. In particular, we describe two sources of cone tip failure, an axis jet driven from the compressed fuel mass and hard photon preheat leaking through the implosion shell, and laser prepulse that can change the position of laser absorption and the angular distribution of the emitted electrons.

On calculating double logarithmical asymptotics of vertex functions defined on the mass shell

International Nuclear Information System (INIS)

Belokurov, V.V.; Usyukina, N.I.

1981-01-01

The essence of the calculation method of double logarithmical asymptotics of vertex functions defined on the mass shell is presented. Using the method the asymptotics of the form-factor of electron is calculated. The ladder and cross-ladder diagrams are asymptotically considerable in every order of the perturbation theory. The way in which the asymptotics of the 4-order diagrams is calculated has been shown. The diagrams of this order and reduction procedures for them are given in a graphic form. The photon mass μ 2 not equal to 0 plays the role of a regulator, removing infrared divergencies. The double logarithmical asymptotics of the form-factor of electron on the mass shell is calculated rigorously in an arbitrary order of the perturbation theory [ru

Public involvement in the Hanford Double-Shell Tank waste disposal program

International Nuclear Information System (INIS)

Triplett, M.B.; Hunter, V.L.

1992-06-01

Hanford's Double-Shell Tank (DST) waste disposal program was redefined following serious challenges to the viability of the previous strategy due to increased regulatory requirements and operating expectations. Redefinition of the DST waste disposal program involved a far-reaching set of decisions and actions. A formal stakeholder involvement process was used to bring the concerns of outside groups into the definition and evaluation of altemative tank waste disposal strategies, broadening the participation and ownership of the revised pregrain. Hanford's Double-Shell Tank (DST) waste disposal strategy, calls for using B-Plant to separate the low-level and high-level portions of the DST waste. This separations step would provide feed to the Hanford Waste Vitrification Plant (HWVP), viewed by many as the cornerstone to Site cleanup. The State of Washington strongly opposed using the 47-year-old B-Plant because it was not built to comply with current environmental regulations. Because of this and other challenges to Hanford's tank waste disposal strategy, the Department of Energy (DOE) Richland Field Office (RL) initiated efforts to redefine the strategy. To support this effort, Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company (WHCP) sought input from outside stakeholder groups (stakeholders are those interest groups that are affected by the outcome of the decision and have a strong desire to ensure that their concerns are addressed) through a formal stakeholder involvement and multi-attribute utility (MAU) analysis process. This paper describes that process and its results

241-AY Double Shell Tanks (DST) Integrity Assessment Report

Energy Technology Data Exchange (ETDEWEB)

JENSEN, C.E.

1999-09-21

This report presents the results of the integrity assessment of the 241-AY double-shell tank farm facility located in the 200 East Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations. are made to ensure the continued safe operation of the tanks.

241-AN Double Shell Tanks (DST) Integrity Assessment Report

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This report presents the results of the integrity assessment of the 241-AN double-shell tank farm facility located in the 200 East Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations, are made to ensure the continued safe operation of the tanks

241-AY Double Shell Tanks (DST) Integrity Assessment Report

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This report presents the results of the integrity assessment of the 241-AY double-shell tank farm facility located in the 200 East Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations, are made to ensure the continued safe operation of the tanks

241-SY Double Shell Tanks (DST) Integrity Assessment Report

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This report presents the results of the integrity assessment of the 241-SY double-shell tank farm facility located in the 200 West Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations, are made to ensure the continued safe operation of the tanks

241-AZ Double-Shell Tanks (DST) Integrity Assessment Report

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This report presents the results of the integrity assessment of the 241-A2 double-shell tank farm facility located in the 200 East Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations, are made to ensure the continued safe operation of the tanks

241-AW Double Shell Tanks (DST) Integrity Assessment Report

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This report presents the results of the integrity assessment of the 241-AW double-shell tank farm facility located in the 200 East Area of the Hanford Site. The assessment included the design evaluation and integrity examinations of the tanks and concluded that the facility is adequately designed, is compatible with the waste, and is fit for use. Recommendations including subsequent examinations, are made to ensure the continued safe operation of the tanks

Mixer pump test plan for double shell tank AZ-101

International Nuclear Information System (INIS)

STAEHR, T.W.

1999-01-01

Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151

A 1-D Study of the Ignition Space for Magnetic Indirect (X-ray) Drive Targets

Energy Technology Data Exchange (ETDEWEB)

Cobble, James Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinars, Daniel Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-06-02

The ICF program today is investigating three approaches to achieving multi-MJ fusion yields and ignition: (1) laser indirect (x-ray) drive on the National Ignition Facility (NIF), (2) laser direct drive (primarily on the Omega laser facility at the University of Rochester), and (3) magnetic direct drive on the Z pulsed power facility. In this white paper we briefly consider a fourth approach, magnetic indirect drive, in which pulsedpower- driven x-ray sources are used in place of laser driven sources. We first look at some of the x-ray sources studied on Z prior to 2007 before the pulsed power ICF program shifted to magnetic direct drive. We then show results from a series of 1D Helios calculations of double-shell capsules that suggest that these sources, scaled to higher temperatures, could be a promising path to achieving multi-MJ fusion yields and ignition. We advocate here that more detailed design calculations with widely accepted 2D/3D ICF codes should be conducted for a better assessment of the prospects.

Shock ignition targets: gain and robustness vs ignition threshold factor

Science.gov (United States)

Atzeni, Stefano; Antonelli, Luca; Schiavi, Angelo; Picone, Silvia; Volponi, Gian Marco; Marocchino, Alberto

2017-10-01

Shock ignition is a laser direct-drive inertial confinement fusion scheme, in which the stages of compression and hot spot formation are partly separated. The hot spot is created at the end of the implosion by a converging shock driven by a final ``spike'' of the laser pulse. Several shock-ignition target concepts have been proposed and relevant gain curves computed (see, e.g.). Here, we consider both pure-DT targets and more facility-relevant targets with plastic ablator. The investigation is conducted with 1D and 2D hydrodynamic simulations. We determine ignition threshold factors ITF's (and their dependence on laser pulse parameters) by means of 1D simulations. 2D simulations indicate that robustness to long-scale perturbations increases with ITF. Gain curves (gain vs laser energy), for different ITF's, are generated using 1D simulations. Work partially supported by Sapienza Project C26A15YTMA, Sapienza 2016 (n. 257584), Eurofusion Project AWP17-ENR-IFE-CEA-01.

Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping

International Nuclear Information System (INIS)

HECHT, S.L.

2000-01-01

Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase

Double Shell Tank (DST) Transfer Pump Subsystem Specification

International Nuclear Information System (INIS)

GRAVES, C.E.

2001-01-01

This specification establishes the performance requirements and provides the references to the requisite codes and standards to be applied during the design of the Double-Shell Tank (DST) Transfer Pump Subsystem that supports the first phase of waste feed delivery (WFD). The DST Transfer Pump Subsystem consists of a pump for supernatant and/or slurry transfer for the DSTs that will be retrieved during the Phase 1 WFD operations. This system is used to transfer low-activity waste (LAW) and high-level waste (HLW) to designated DST staging tanks. It also will deliver blended LAW and HLW feed from these staging tanks to the River Protection Project (RPP) Waste Treatment Plant where it will be processed into an immobilized waste form. This specification is intended to be the basis for new projects/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

On buckling of double-shell-stiffened cylindrical steel structures

International Nuclear Information System (INIS)

Chen, S.J.; Chiu, K.D.; Odar, E.

1981-01-01

Buckling analysis methods and acceptance criteria for single shells of various configurations are well documented and adequately covered by many codes. There are, however, no guidelines or criteria for large Double-Shell-Stiffened (DSS) structures, which have been used recently in nuclear power plant applications. The existing codes for buckling analysis cannot be directly utilized because of the uniqueness of structural configuration and complexity of loading. This paper discusses a method for determining the critical buckling loads for this type of structure under a multitude load and suggests buckling criteria for the design of DSS structures. The method commonly used to determine the critical buckling loads for a single shell with or without stiffeners applies reduction factors to the theoretical results. The capacity reduction factors, which are often obtained from experimental results, include plasticity corrections and account for the difference between actual and theoretical buckling loads resulting from the effects of imperfections and nonlinearities. The interaction formulas derived from experimental results can be used to compute the interaction effects of three stress components. This paper extends these concepts and discusses their applicability to a DSS cylindrical structure. (orig./HP)

Acceptance criteria for non-destructive examination of double-shell tanks

International Nuclear Information System (INIS)

Jensen, C.E.

1995-09-01

This supporting document provides requirements for acceptance of relevant indications found during non-destructive examination of double-shell tanks (DSTs) at Hanford 200 areas. Requirements for evaluation of relevant indications are provided to determine acceptability of continued safe operation of the DSTs. Areas of the DSTs considered include the tank wall vapor space, liquid-vapor interface, wetted tank wall, sludge-liquid interface, and the knuckle region

Evaluation of Flygt Propeller Mixers for Double-Shell Tank (DST) High Level Waste Auxiliary Solids Mobilization

International Nuclear Information System (INIS)

PACQUET, E.A.

2000-01-01

The River Protection Project (RPP) is planning to retrieve radioactive waste from the single-shell tanks (SST) and double-shell tanks (DST) underground at the Hanford Site. This waste will then be transferred to a waste treatment plant to be immobilized (vitrified) in a stable glass form. Over the years, the waste solids in many of the tanks have settled to form a layer of sludge at the bottom. The thickness of the sludge layer varies from tank to tank, from no sludge or a few inches of sludge to about 15 ft of sludge. The purpose of this technology and engineering case study is to evaluate the Flygt(trademark) submersible propeller mixer as a potential technology for auxiliary mobilization of DST HLW solids. Considering the usage and development to date by other sites in the development of this technology, this study also has the objective of expanding the knowledge base of the Flygt(trademark) mixer concept with the broader perspective of Hanford Site tank waste retrieval. More specifically, the objectives of this study delineated from the work plan are described

Evaluation of Flygt Propeller Xixers for Double Shell Tank (DST) High Level Waste Auxiliary Solids Mobilization

Energy Technology Data Exchange (ETDEWEB)

PACQUET, E.A.

2000-07-20

The River Protection Project (RPP) is planning to retrieve radioactive waste from the single-shell tanks (SST) and double-shell tanks (DST) underground at the Hanford Site. This waste will then be transferred to a waste treatment plant to be immobilized (vitrified) in a stable glass form. Over the years, the waste solids in many of the tanks have settled to form a layer of sludge at the bottom. The thickness of the sludge layer varies from tank to tank, from no sludge or a few inches of sludge to about 15 ft of sludge. The purpose of this technology and engineering case study is to evaluate the Flygt{trademark} submersible propeller mixer as a potential technology for auxiliary mobilization of DST HLW solids. Considering the usage and development to date by other sites in the development of this technology, this study also has the objective of expanding the knowledge base of the Flygt{trademark} mixer concept with the broader perspective of Hanford Site tank waste retrieval. More specifically, the objectives of this study delineated from the work plan are described.

HIGH-RESOLUTION SIMULATIONS OF CONVECTION PRECEDING IGNITION IN TYPE Ia SUPERNOVAE USING ADAPTIVE MESH REFINEMENT

International Nuclear Information System (INIS)

Nonaka, A.; Aspden, A. J.; Almgren, A. S.; Bell, J. B.; Zingale, M.; Woosley, S. E.

2012-01-01

We extend our previous three-dimensional, full-star simulations of the final hours of convection preceding ignition in Type Ia supernovae to higher resolution using the adaptive mesh refinement capability of our low Mach number code, MAESTRO. We report the statistics of the ignition of the first flame at an effective 4.34 km resolution and general flow field properties at an effective 2.17 km resolution. We find that off-center ignition is likely, with radius of 50 km most favored and a likely range of 40-75 km. This is consistent with our previous coarser (8.68 km resolution) simulations, implying that we have achieved sufficient resolution in our determination of likely ignition radii. The dynamics of the last few hot spots preceding ignition suggest that a multiple ignition scenario is not likely. With improved resolution, we can more clearly see the general flow pattern in the convective region, characterized by a strong outward plume with a lower speed recirculation. We show that the convective core is turbulent with a Kolmogorov spectrum and has a lower turbulent intensity and larger integral length scale than previously thought (on the order of 16 km s –1 and 200 km, respectively), and we discuss the potential consequences for the first flames.

Ignition and combustion characteristics of metallized propellants

Science.gov (United States)

Turns, Stephen R.; Mueller, D. C.

1993-01-01

Experimental and analytical investigations focusing on secondary atomization and ignition characteristics of aluminum/liquid hydrocarbon slurry propellants were conducted. Experimental efforts included the application of a laser-based, two-color, forward-scatter technique to simultaneously measure free-flying slurry droplet diameters and velocities for droplet diameters in the range of 10-200 microns. A multi-diffusion flame burner was used to create a high-temperature environment into which a dilute stream of slurry droplets could be introduced. Narrowband measurements of radiant emission were used to determine if ignition of the aluminum in the slurry droplet had occurred. Models of slurry droplet shell formation were applied to aluminum/liquid hydrocarbon propellants and used to ascertain the effects of solids loading and ultimate particle size on the minimum droplet diameter that will permit secondary atomization. For a 60 weight-percent Al slurry, the limiting critical diameter was predicted to be 34.7 microns which is somewhat greater than the 20-25 micron limiting diameters determined in the experiments. A previously developed model of aluminum ignition in a slurry droplet was applied to the present experiments and found to predict ignition times in reasonable agreement with experimental measurements. A model was also developed that predicts the mechanical stress in the droplet shell and a parametric study was conducted. A one-dimensional model of a slurry-fueled rocket combustion chamber was developed. This model includes the processes of liquid hydrocarbon burnout, secondary atomization, aluminum ignition, and aluminum combustion. Also included is a model for radiant heat transfer from the hot aluminum oxide particles to the chamber walls. Exercising this model shows that only a modest amount of secondary atomization is required to reduce residence times for aluminum burnout, and thereby maintain relatively short chamber lengths. The model also predicts

A risk management approach to double-shell tank waste volume versus storage capacity

Energy Technology Data Exchange (ETDEWEB)

Coles, G.A. [Westinghouse Hanford Co., Richland, WA (United States); Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J. [ARES Corp. (United States)

1996-01-01

A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences.

A risk management approach to double-shell tank waste volume versus storage capacity

International Nuclear Information System (INIS)

Coles, G.A.; Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J.

1996-01-01

A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences

Double shell slurry low-temperature corrosion tests

International Nuclear Information System (INIS)

Divine, J.R.; Bowen, W.M.; McPartland, S.A.; Elmore, R.P.; Engel, D.W.

1983-09-01

A series of year-long tests have been completed on potential double shell slurry (DSS) compositions at temperatures up to 100 0 C. These tests have sought data on uniform corrosion, pitting, and stress-corrosion cracking. No indication of the latter two types of corrosion were observed within the test matrix. Corrosion rates after four months were generally below the 1 mpy (25 μm/y) design limit. By the end of twelve months all results were below this limit and, except for very concentrated mixtures, all were below 0.5 mpy. Prediction equations were generated from a model fitted to the data. The equations provide a rapid means of estimating the corrosion rate for proposed DSS compositions

Ignition during hydrogen release from high pressure into the atmosphere

Science.gov (United States)

Oleszczak, P.; Wolanski, P.

2010-12-01

The first investigations concerned with a problem of hydrogen jet ignition, during outflow from a high-pressure vessel were carried out nearly 40 years ago by Wolanski and Wojcicki. The research resulted from a dramatic accident in the Chorzow Chemical Plant Azoty, where the explosion of a synthesis gas made up of a mixture composed of three moles of hydrogen per mole of nitrogen, at 300°C and 30 MPa killed four people. Initial investigation had excluded potential external ignition sources and the main aim of the research was to determine the cause of ignition. Hydrogen is currently considered as a potential fuel for various vehicles such as cars, trucks, buses, etc. Crucial safety issues are of potential concern, associated with the storage of hydrogen at a very high pressure. Indeed, the evidence obtained nearly 40 years ago shows that sudden rupture of a high-pressure hydrogen storage tank or other component can result in ignition and potentially explosion. The aim of the present research is identification of the conditions under which hydrogen ignition occurs as a result of compression and heating of the air by the shock wave generated by discharge of high-pressure hydrogen. Experiments have been conducted using a facility constructed in the Combustion Laboratory of the Institute of Heat Engineering, Warsaw University of Technology. Tests under various configurations have been performed to determine critical conditions for occurrence of high-pressure hydrogen ignition. The results show that a critical pressure exists, leading to ignition, which depends mainly on the geometric configuration of the outflow system, such as tube diameter, and on the presence of obstacles.

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility

Science.gov (United States)

Olson, R. E.; Leeper, R. J.; Kline, J. L.; Zylstra, A. B.; Yi, S. A.; Biener, J.; Braun, T.; Kozioziemski, B. J.; Sater, J. D.; Bradley, P. A.; Peterson, R. R.; Haines, B. M.; Yin, L.; Berzak Hopkins, L. F.; Meezan, N. B.; Walters, C.; Biener, M. M.; Kong, C.; Crippen, J. W.; Kyrala, G. A.; Shah, R. C.; Herrmann, H. W.; Wilson, D. C.; Hamza, A. V.; Nikroo, A.; Batha, S. H.

2016-12-01

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D2 and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12 30 ) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

Functional Group Analysis for Diesel-like Mixing-Controlled Compression Ignition Combustion Blendstocks

Energy Technology Data Exchange (ETDEWEB)

Gaspar, Daniel J.; McCormick, Robert L.; Polikarpov, Evgueni; Fioroni, Gina; George, Anthe; Albrecht, Karl O.

2016-12-30

This report addresses the suitability of hydrocarbon and oxygenate functional groups for use as a diesel-like fuel blending component in an advanced, mixing-controlled, compression ignition combustion engine. The functional groups are chosen from those that could be derived from a biomass feedstock, and represent a full range of chemistries. This first systematic analysis of functional groups will be of value to all who are pursuing new bio-blendstocks for diesel-like fuels.

Electron Shock Ignition of Inertial Fusion Targets

International Nuclear Information System (INIS)

Shang, W. L.; Betti, R.; Hu, S. X.; Woo, K.; Hao, L.

2017-01-01

Here, it is shown that inertial fusion targets designed with low implosion velocities can be shock ignited using laser–plasma interaction generated hot electrons (hot-e) to obtain high-energy gains. These designs are robust to multimode asymmetries and are predicted to ignite even for significantly distorted implosions. Electron shock ignition requires tens of kilojoules of hot-e, which can only be produced on a large laser facility like the National Ignition Facility, with the laser to hot-e conversion efficiency greater than 10% at laser intensities ~10 16 W/cm 2 .

Ignition parameters and early flame kernel development of laser-ignited combustible gas mixtures

International Nuclear Information System (INIS)

Kopecek, H.; Wintner, E.; Ruedisser, D.; Iskra, K.; Neger, T.

2002-01-01

Full text: Laser induced breakdown of focused pulsed laser radiation, the subsequent plasma formation and thermalization offers a possibility of ignition of combustible gas mixtures free from electrode interferences, an arbitrary choice of the location within the medium and exact timing regardless of the degree of turbulence. The development and the decreasing costs of solid state laser technologies approach the pay-off for the higher complexity of such an ignition system due to several features unique to laser ignition. The feasability of laser ignition was demonstrated in an 1.5 MW(?) natural gas engine, and several investigations were performed to determine optimal ignition energies, focus shapes and laser wavelengths. The early flame kernel development was investigated by time resolved planar laser induced fluorescence of the OH-radical which occurs predominantly in the flame front. The flame front propagation showed typical features like toroidal initial flame development, flame front return and highly increased flame speed along the laser focus axis. (author)

Seaurchin-like hierarchical NiCo2O4@NiMoO4 core-shell nanomaterials for high performance supercapacitors.

Science.gov (United States)

Zhang, Qiang; Deng, Yanghua; Hu, Zhonghua; Liu, Yafei; Yao, Mingming; Liu, Peipei

2014-11-14

A novel electrode material of the three-dimensional (3D) multicomponent oxide NiCo2O4@NiMoO4 core-shell was synthesized via a facile two-step hydrothermal method using a post-annealing procedure. The uniform NiMoO4 nanosheets were grown on the seaurchin-like NiCo2O4 backbone to form a NiCo2O4@NiMoO4 core-shell material constructed by interconnected ultrathin nanosheets, so as to produce hierarchical mesopores with a large specific surface area of 100.3 m(2) g(-1). The porous feature and core-shell structure can facilitate the penetration of electrolytic ions and increases the number of electroactive sites. Hence, the NiCo2O4@NiMoO4 material exhibited a high specific capacitance of 2474 F g(-1) and 2080 F g(-1) at current densities of 1 A g(-1) and 20 A g(-1) respectively, suggesting that it has not only a very large specific capacitance, but also a good rate performance. In addition, the capacitance loss was only 5.0% after 1000 cycles of charge and discharge tests at the current density of 10 A g(-1), indicating high stability. The excellent electrochemical performance is mainly attributed to its 3D core-shell and hierarchical mesoporous structures which can provide unobstructed pathways for the fast diffusion and transportation of ions and electrons, a large number of active sites and good strain accommodation.

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SEISMIC ANALYSIS OF HANFORD DOUBLE SHELL TANKS

Energy Technology Data Exchange (ETDEWEB)

MACKEY TC; RINKER MW; CARPENTER BG; HENDRIX C; ABATT FG

2009-01-15

M&D Professional Services, Inc. (M&D) is under subcontract to Pacific Northwest National Laboratories (PNNL) to perform seismic analysis of the Hanford Site Double-Shell Tanks (DSTs) in support of a project entitled Double-Shell Tank (DST) Integrity Project - DST Thermal and Seismic Analyses. The original scope of the project was to complete an up-to-date comprehensive analysis of record of the DST System at Hanford in support of Tri-Party Agreement Milestone M-48-14. The work described herein was performed in support of the seismic analysis of the DSTs. The thermal and operating loads analysis of the DSTs is documented in Rinker et al. (2004). Although Milestone M-48-14 has been met, Revision I is being issued to address external review comments with emphasis on changes in the modeling of anchor bolts connecting the concrete dome and the steel primary tank. The work statement provided to M&D (PNNL 2003) required that a nonlinear soil structure interaction (SSI) analysis be performed on the DSTs. The analysis is required to include the effects of sliding interfaces and fluid sloshing (fluid-structure interaction). SSI analysis has traditionally been treated by frequency domain computer codes such as SHAKE (Schnabel, et al. 1972) and SASSI (Lysmer et al. 1999a). Such frequency domain programs are limited to the analysis of linear systems. Because of the contact surfaces, the response of the DSTs to a seismic event is inherently nonlinear and consequently outside the range of applicability of the linear frequency domain programs. That is, the nonlinear response of the DSTs to seismic excitation requires the use of a time domain code. The capabilities and limitations of the commercial time domain codes ANSYS{reg_sign} and MSC Dytran{reg_sign} for performing seismic SSI analysis of the DSTs and the methodology required to perform the detailed seismic analysis of the DSTs has been addressed in Rinker et al (2006a). On the basis of the results reported in Rinker et al

A double copy for N=2 supergravity: a linearised tale told on-shell

International Nuclear Information System (INIS)

Cardoso, G.L.; Nagy, S.; Nampuri, S.

2016-01-01

We construct the on-shell double copy dictionary for linearised four-dimensional N=2 supergravity coupled to one vector multiplet with a quadratic prepotential. We apply this dictionary to the weak-field approximation of dyonic BPS black holes in this theory.

A double copy for N=2 supergravity: a linearised tale told on-shell

Energy Technology Data Exchange (ETDEWEB)

Cardoso, G.L.; Nagy, S.; Nampuri, S. [Center for Mathematical Analysis, Geometry and Dynamical Systems, Department of Mathematics, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

2016-10-24

We construct the on-shell double copy dictionary for linearised four-dimensional N=2 supergravity coupled to one vector multiplet with a quadratic prepotential. We apply this dictionary to the weak-field approximation of dyonic BPS black holes in this theory.

Double-shell tank waste transfer facilities integrity assessment plan

International Nuclear Information System (INIS)

Hundal, T.S.

1998-01-01

This document presents the integrity assessment plan for the existing double-shell tank waste transfer facilities system in the 200 East and 200 West Areas of Hanford Site. This plan identifies and proposes the integrity assessment elements and techniques to be performed for each facility. The integrity assessments of existing tank systems that stores or treats dangerous waste is required to be performed to be in compliance with the Washington State Department of Ecology Dangerous Waste Regulations, Washington Administrative Code WAC-173-303-640 requirements

Evaluation of remaining life of the double-shell tank waste systems

International Nuclear Information System (INIS)

Schwenk, E.B.

1995-01-01

A remaining life assessment of the DSTs (double-shell tanks) and their associated waste transfer lines, for continued operation over the next 10 years, was favorable. The DST assessment was based on definition of significant loads, evaluation of data for possible material degradation and geometric changes and evaluation of structural analyses. The piping assessment was based primarily on service experience

Evaluation of remaining life of the double-shell tank waste systems

Energy Technology Data Exchange (ETDEWEB)

Schwenk, E.B.

1995-05-04

A remaining life assessment of the DSTs (double-shell tanks) and their associated waste transfer lines, for continued operation over the next 10 years, was favorable. The DST assessment was based on definition of significant loads, evaluation of data for possible material degradation and geometric changes and evaluation of structural analyses. The piping assessment was based primarily on service experience.

Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer

International Nuclear Information System (INIS)

Onishi, Yasuo; Wells, Beric E; Hartley, Stacey A; Enderlin, Carl W

2001-01-01

PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102

Studies of electron and proton isochoric heating for fast ignition

International Nuclear Information System (INIS)

Mackinnon, A; Key, M; Akli, K; Beg, F; Clarke, R; Clarke, D; Chen, M; Chung, H; Chen, S; Freeman, R; Green, J; Gu, P; Gregori, G; Highbarger, K; Habara, H; Hatchett, S; Hey, D; Heathcote, R; Hill, J; King, J; Kodama, R; Koch, J; Lancaster, K; Langdon, B; Murphy, C; Norreys, P; Neely, D; Nakatsutsumi, M; Nakamura, H; Patel, N; Patel, P; Pasley, J; Snavley, R; Stephens, R; Stoeckl, C; Foord, M; Tabak, M; Theobald, W; Storm, M; Tanaka, K; Tempo, M; Toley, M; Town, R; Wilks, S; VanWoerkom, L; Weber, R; Yabuuchi, T; Zhang, B

2006-01-01

Isochoric heating of inertially confined fusion plasmas by laser driven MeV electrons or protons is an area of great topical interest in the inertial confinement fusion community, particularly with respect to the fast ignition (FI) proposal to use this technique to initiate burn in a fusion capsule. Experiments designed to investigate electron isochoric heating have measured heating in two limiting cases of interest to fast ignition, small planar foils and hollow cones. Data from Cu Kα fluorescence, crystal x-ray spectroscopy of Cu K shell emission, and XUV imaging at 68eV and 256 eV are used to test PIC and Hybrid PIC modeling of the interaction. Isochoric heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside a cone have been studied with the same diagnostic methods plus imaging of proton induced Kα. Conversion efficiency to protons has also been measured and modeled. Conclusions from the proton and electron heating experiments will be presented. Recent advances in modeling electron transport and innovative target designs for reducing igniter energy and increasing gain curves will also be discussed

Fluence-compensated down-scattered neutron imaging using the neutron imaging system at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Casey, D. T., E-mail: casey21@llnl.gov; Munro, D. H.; Grim, G. P.; Landen, O. L.; Spears, B. K.; Fittinghoff, D. N.; Field, J. E.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Volegov, P. L.; Merrill, F. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2016-11-15

The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

Double-shell target designs for the Los Alamos Scientific Laboratory eight-beam laser system

International Nuclear Information System (INIS)

Kindel, J.M.; Stroscio, M.A.

1978-03-01

We investigate two double-pusher laser fusion targets, one that incorporates an outer exploding pusher shell and another that uses velocity multiplication. Specific designs are presented for the Los Alamos Scientific Laboratory Eight-Beam Laser System

Simulation study of 3–5 keV x-ray conversion efficiency from Ar K-shell vs. Ag L-shell targets on the National Ignition Facility laser

Energy Technology Data Exchange (ETDEWEB)

Kemp, G. E., E-mail: kemp10@llnl.gov; Colvin, J. D.; Fournier, K. B.; May, M. J.; Barrios, M. A.; Patel, M. V.; Scott, H. A.; Marinak, M. M. [Lawrence Livermore National Laboratory, Livermore, California 94550-9698 (United States)

2015-05-15

Tailored, high-flux, multi-keV x-ray sources are desirable for studying x-ray interactions with matter for various civilian, space and military applications. For this study, we focus on designing an efficient laser-driven non-local thermodynamic equilibrium 3–5 keV x-ray source from photon-energy-matched Ar K-shell and Ag L-shell targets at sub-critical densities (∼n{sub c}/10) to ensure supersonic, volumetric laser heating with minimal losses to kinetic energy, thermal x rays and laser-plasma instabilities. Using HYDRA, a multi-dimensional, arbitrary Lagrangian-Eulerian, radiation-hydrodynamics code, we performed a parameter study by varying initial target density and laser parameters for each material using conditions readily achievable on the National Ignition Facility (NIF) laser. We employ a model, benchmarked against Kr data collected on the NIF, that uses flux-limited Lee-More thermal conductivity and multi-group implicit Monte-Carlo photonics with non-local thermodynamic equilibrium, detailed super-configuration accounting opacities from CRETIN, an atomic-kinetics code. While the highest power laser configurations produced the largest x-ray yields, we report that the peak simulated laser to 3–5 keV x-ray conversion efficiencies of 17.7% and 36.4% for Ar and Ag, respectively, occurred at lower powers between ∼100–150 TW. For identical initial target densities and laser illumination, the Ag L-shell is observed to have ≳10× higher emissivity per ion per deposited laser energy than the Ar K-shell. Although such low-density Ag targets have not yet been demonstrated, simulations of targets fabricated using atomic layer deposition of Ag on silica aerogels (∼20% by atomic fraction) suggest similar performance to atomically pure metal foams and that either fabrication technique may be worth pursuing for an efficient 3–5 keV x-ray source on NIF.

Final results of double-shell tank 241-AZ-101 ultrasonic inspection

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AZ-101. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AZ-101 primary tank wall and welds. The inspection found one reportable indication of thinning and no reportable pitting, corrosion, or cracking

Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

Energy Technology Data Exchange (ETDEWEB)

Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

2014-11-15

In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ∼300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub β}). The detectors impulse response function was measured in situ on NIF short-pulse (∼90 ps) experiments, and in off-line tests.

Double Shell Tank (DST) Process Waste Sampling Subsystem Definition Report

International Nuclear Information System (INIS)

RASMUSSEN, J.H.

2000-01-01

This report defines the Double-Shell Tank (DST) Process Waste Sampling Subsystem (PWSS). This subsystem definition report fully describes and identifies the system boundaries of the PWSS. This definition provides a basis for developing functional, performance, and test requirements (i.e., subsystem specification), as necessary, for the PWSS. The resultant PWSS specification will include the sampling requirements to support the transfer of waste from the DSTs to the Privatization Contractor during Phase 1 of Waste Feed Delivery

Tank characterization report for double-shell tank 241-AP-102

International Nuclear Information System (INIS)

LAMBERT, S.L.

1999-01-01

In April 1993, Double-Shell Tank 241-AP-102 was sampled to determine waste feed characteristics for the Hanford Grout Disposal Program. This Tank Characterization Report presents an overview of that tank sampling and analysis effort, and contains observations regarding waste characteristics, expected bulk inventory, and concentration data for the waste contents based on this latest sampling data and information on the history of the tank. Finally, this report makes recommendations and conclusions regarding tank operational safety issues

Remote ignitability analysis of high-level radioactive waste

International Nuclear Information System (INIS)

Lundholm, C.W.; Morgan, J.M.; Shurtliff, R.M.; Trejo, L.E.

1992-09-01

The Idaho Chemical Processing Plant (ICPP), was used to reprocess nuclear fuel from government owned reactors to recover the unused uranium-235. These processes generated highly radioactive liquid wastes which are stored in large underground tanks prior to being calcined into a granular solid. The Resource Conservation and Recovery Act (RCRA) and state/federal clean air statutes require waste characterization of these high level radioactive wastes for regulatory permitting and waste treatment purposes. The determination of the characteristic of ignitability is part of the required analyses prior to calcination and waste treatment. To perform this analysis in a radiologically safe manner, a remoted instrument was needed. The remote ignitability Method and Instrument will meet the 60 deg. C. requirement as prescribed for the ignitability in method 1020 of SW-846. The method for remote use will be equivalent to method 1020 of SW-846

Reaction-in-flight neutrons as a signature for shell mixing in National Ignition Facility capsules

International Nuclear Information System (INIS)

Hayes, A. C.; Bradley, P. A.; Grim, G. P.; Jungman, Gerard; Wilhelmy, J. B.

2010-01-01

Analytic calculations and results from computational simulations are presented that suggest that reaction-in-flight (RIF) neutrons can be used to diagnose mixing of the ablator shell material into the fuel in deuterium-tritium (DT) capsules designed for the National Ignition Facility (NIF) [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. Such mixing processes in NIF capsules are of fundamental physical interest and can have important effects on capsule performance, quenching the total thermonuclear yield. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIF production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to down-scattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.

Mathematical Modeling and Kinematics Analysis of Double Spherical Shell Rotary Docking Skirt

Directory of Open Access Journals (Sweden)

Gong Haixia

2017-01-01

Full Text Available In order to solve the problem of large trim and heel angles of the wrecked submarine, the double spherical shell rotating docking skirt is studied. According to the working principle of the rotating docking skirt, and the fixed skirt, the directional skirt, the angle skirt are simplified as the connecting rod. Therefore, the posture equation and kinematics model of the docking skirt are deduced, and according to the kinematics model, the angle of rotation of the directional skirt and the angle skirt is obtained when the wrecked submarine is in different trim and heel angles. Through the directional skirt and angle skirt with the matching rotation can make docking skirt interface in the 0°~2γ range within the rotation, to complete the docking skirt and the wrecked submarine docking. The MATLAB software is used to visualize the rotation angle of fixed skirt and directional skirt, which lays a good foundation for the development of the control of the double spherical shell rotating docking skirt in future.

The high velocity, high adiabat, ``Bigfoot'' campaign and tests of indirect-drive implosion scaling

Science.gov (United States)

Casey, Daniel

2017-10-01

To achieve hotspot ignition, inertial confinement fusion (ICF) implosions must achieve high hotspot internal energy that is inertially confined by a dense shell of DT fuel. To accomplish this, implosions are designed to achieve high peak implosion velocity, good energy coupling between the hotspot and imploding shell, and high areal-density at stagnation. However, experiments have shown that achieving these simultaneously is extremely challenging, partly because of inherent tradeoffs between these three interrelated requirements. The Bigfoot approach is to intentionally trade off high convergence, and therefore areal-density, in favor of high implosion velocity and good coupling between the hotspot and shell. This is done by intentionally colliding the shocks in the DT ice layer. This results in a short laser pulse which improves hohlraum symmetry and predictability while the reduced compression improves hydrodynamic stability. The results of this campaign will be reviewed and include demonstrated low-mode symmetry control at two different hohlraum geometries (5.75 mm and 5.4 mm diameters) and at two different target scales (5.4 mm and 6.0 mm hohlraum diameters) spanning 300-430 TW in laser power and 0.8-1.7 MJ in laser energy. Results of the 10% scaling between these designs for the hohlraum and capsule will be presented. Hydrodynamic instability growth from engineering features like the capsule fill tube are currently thought to be a significant perturbation to the target performance and a major factor in reducing its performance compared to calculations. Evidence supporting this hypothesis as well as plans going forward will be presented. Ongoing experiments are attempting to measure the impact on target performance from increase in target scale, and the preliminary results will also be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Neutrinoless double-β decay matrix elements in large shell-model spaces with the generator-coordinate method

Science.gov (United States)

Jiao, C. F.; Engel, J.; Holt, J. D.

2017-11-01

We use the generator-coordinate method (GCM) with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-β decay of 48Ca, 76Ge, and 82Se. We work in one major shell for the first isotope, in the f5 /2p g9 /2 space for the second and third, and finally in two major shells for all three. Our coordinates include not only the usual axial deformation parameter β , but also the triaxiality angle γ and neutron-proton pairing amplitudes. In the smaller model spaces our matrix elements agree well with those of full shell-model diagonalization, suggesting that our Hamiltonian-based GCM captures most of the important valence-space correlations. In two major shells, where exact diagonalization is not currently possible, our matrix elements are only slightly different from those in a single shell.

Mixer pump test plan for double-shell tank AZ-101. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Symons, G.A.

1996-02-01

Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank waste. Mixer pumps were chosen as the planned method of retrieval for DSTs, based on engineering technology studies, past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site.

Mixer pump test plan for double-shell tank AZ-101. Revision 1

International Nuclear Information System (INIS)

Symons, G.A.

1996-02-01

Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank waste. Mixer pumps were chosen as the planned method of retrieval for DSTs, based on engineering technology studies, past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site

Improving a high-efficiency, gated spectrometer for x-ray Thomson scattering experiments at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Döppner, T., E-mail: doeppner1@llnl.gov; Bachmann, B.; Emig, J.; Hardy, M.; Kalantar, D. H.; Kritcher, A. L.; Landen, O. L.; Ma, T.; Wood, R. D. [Lawrence Livermore National Laboratory, Livermore, California 94720 (United States); Kraus, D.; Saunders, A. M. [University of California, Berkeley, California 94720 (United States); Neumayer, P. [Gesellschaft für Schwerionenphysik, Darmstadt (Germany); Falcone, R. W. [University of California, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fletcher, L. B. [SLAC National Accelerator Laboratory, Menlo Park, California 94720 (United States)

2016-11-15

We are developing x-ray Thomson scattering for applications in implosion experiments at the National Ignition Facility. In particular we have designed and fielded MACS, a high-efficiency, gated x-ray spectrometer at 7.5–10 keV [T. Döppner et al., Rev. Sci. Instrum. 85, 11D617 (2014)]. Here we report on two new Bragg crystals based on Highly Oriented Pyrolytic Graphite (HOPG), a flat crystal and a dual-section cylindrically curved crystal. We have performed in situ calibration measurements using a brass foil target, and we used the flat HOPG crystal to measure Mo K-shell emission at 18 keV in 2nd order diffraction. Such high photon energy line emission will be required to penetrate and probe ultra-high-density plasmas or plasmas of mid-Z elements.

Preparation of Au cone for fast ignition target

International Nuclear Information System (INIS)

Du Kai; Zhou Lan; Zhang Lin; Wan Xiaobo; Xiao Jiang

2005-01-01

Cone-shell target is typically used for the fast ignition experiments of inertial confinement fusion. In order to fabricate cone-shell target the Au cones with different angles were produced by electroplating and precise machining. The Au electroplating process was introduced in the paper, and the dependence of coating quality on the parameters, such as composition, temperature, pH of electroplating bath, current density and tip effect, were discussed. (author)

Shape evolution of new-phased lepidocrocite VOOH from single-shelled to double-shelled hollow nanospheres on the basis of programmed reaction-temperature strategy.

Science.gov (United States)

Wu, Changzheng; Zhang, Xiaodong; Ning, Bo; Yang, Jinlong; Xie, Yi

2009-07-06

Solid templates have been long regarded as one of the most promising ways to achieve single-shelled hollow nanostructures; however, few effective methods for the construction of multishelled hollow objects from their solid template counterparts have been developed. We report here, for the first time, a novel and convenient route to synthesizing double-shelled hollow spheres from the solid templates via programming the reaction-temperature procedures. The programmed temperature strategy developed in this work then provides an essential and general access to multishelled hollow nanostructures based on the designed extension of single-shelled hollow objects, independent of their outside contours, such as tubes, hollow spheres, and cubes. Starting from the V(OH)(2)NH(2) solid templates, we show that the relationship between the hollowing rate and the reaction temperature obey the Van't Hoff rule and Arrhenius activation-energy equation, revealing that it is the chemical reaction rather than the diffusion process that guided the whole hollowing process, despite the fact that the coupled reaction/diffusion process is involved in the hollowing process. Using the double-shelled hollow spheres as the PCM (CaCl(2).6H(2)O) matrix grants much better thermal-storage stability than that for the nanoparticles counterpart, revealing that the designed nanostructures can give rise to significant improvements for the energy-saving performance in future "smart house" systems.

A self-similar isochoric implosion for fast ignition

International Nuclear Information System (INIS)

Clark, D.S.; Tabak, M.

2007-01-01

Various gain models have shown the potentially great advantages of fast ignition (FI) inertial confinement fusion (ICF) over its conventional hot spot ignition counterpart (e.g. Atzeni S. 1999 Phys. Plasmas 6 3316; Tabak M. et al 2006 Fusion Sci. Technol. 49 254). These gain models, however, all assume nearly uniform density fuel assemblies. In contrast, conventional ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pressure hot spot. Hence, to realize fully the advantages of FI, an alternative implosion design must be found which yields nearly isochoric fuel assemblies without substantial hot spots. Here, it is shown that a self-similar spherical implosion of the type originally studied by Guderley (1942 Luftfahrtforschung 19 302) may be employed to yield precisely such quasi-isochoric imploded states. The difficulty remains, however, of accessing these self-similarly imploding configurations from initial conditions representing an actual ICF target, namely a uniform, solid-density shell at rest. Furthermore, these specialized implosions must be realized for practicable drive parameters and at the scales and energies of interest in ICF. A direct-drive implosion scheme is presented which meets all of these requirements and reaches a nearly isochoric assembled density of 300 g cm -3 and areal density of 2.4 g cm -2 using 485 kJ of laser energy

Two-Dimensional Simulations of Electron Shock Ignition at the Megajoule Scale

Science.gov (United States)

Shang, W.; Betti, R.

2016-10-01

Shock ignition uses a late strong shock to ignite the hot spot of an inertial confinement fusion capsule. In the standard shock-ignition scheme, an ignitor shock is launched by the ablation pressure from a spike in laser intensity. Recent experiments on OMEGA have shown that focused beams with intensity up to 6 ×1015 W /cm2 can produce copious amounts of hot electrons. The hot electrons are produced by laser-plasma instabilities (LPI's) and can carry up to 15 % of the instantaneous laser power. Megajoule-scale targets will likely produce even more hot electrons because of the large plasma scale length. We show that it is possible to design ignition targets with low implosion velocities that can be shock ignited using LPI-generated hot electrons to obtain high energy gains. These designs are robust to low-mode asymmetries and they ignite even for highly distorted implosions. Electron shock ignition requires tens of kilojoules of hot electrons, which can only be produced on a large laser facility like the National Ignition Facility. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Double-Shell Tank (DST) Maintenance and Recovery Subsystem Definition Report

International Nuclear Information System (INIS)

SMITH, E.A.

2000-01-01

The description of the Double-Shell Tank (DST) Maintenance and Recovery Subsystem presented in this document was developed to establish its boundaries. The DST Maintenance and Recovery Subsystem consists of new and existing equipment and facilities used to provide tank farm operators logistic support and problem resolution for the DST System during operations. This support will include evaluating equipment status, performing preventive and corrective maintenance, developing work packages, managing spares and consumables, supplying tooling, and training maintenance and operations personnel

Final results of double-shell tank 241-AY-102 ultrasonic inspection

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AY-102. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AY-102 primary tank wall and welds. The inspection found some indication of insignificant general and local wall thinning with no cracks detected

Final results of double-shell tank 241-AN-105 ultrasonic inspection

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AN-105. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AN-105 primary tank wall primary knuckle, and secondary tank bottom. The inspection found some indication of general and local wall thinning with no cracks detected

Maximum credibly yield for deuteriuim-filled double shell imaging targets meeting requirements for yield bin Category A

Energy Technology Data Exchange (ETDEWEB)

Wilson, Douglas Carl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Loomis, Eric Nicholas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-08-17

We are anticipating our first NIF double shell shot using an aluminum ablator and a glass inner shell filled with deuterium shown in figure 1. The expected yield is between a few 10¹⁰ to a few 10¹¹ dd neutrons. The maximum credible yield is 5e+13. This memo describes why, and what would be expected with variations on the target. This memo evaluates the maximum credible yield for deuterium filled double shell capsule targets with an aluminum ablator shell and a glass inner shell in yield Category A (< 10¹⁴ neutrons). It also pertains to fills of gas diluted with hydrogen, helium (³He or ⁴He), or any other fuel except tritium. This memo does not apply to lower z ablator dopants, such as beryllium, as this would increase the ablation efficiency. This evaluation is for 5.75 scale hohlraum targets of either gold or uranium with helium gas fills with density between 0 and 1.6 mg/cc. It could be extended to other hohlraum sizes and shapes with slight modifications. At present only laser pulse energies up to 1.5 MJ were considered with a single step laser pulse of arbitrary shape. Since yield decreases with laser energy for this target, the memo could be extended to higher laser energies if desired. These maximum laser parameters of pulses addressed here are near the edge of NIF’s capability, and constitute the operating envelope for experiments covered by this memo. We have not considered multiple step pulses, would probably create no advantages in performance, and are not planned for double shell capsules. The main target variables are summarized in Table 1 and explained in detail in the memo. Predicted neutron yields are based on 1D and 2D clean simulations.

Antiproton fast ignition for inertial confinement fusion

International Nuclear Information System (INIS)

Perkins, L.J.

1999-01-01

With 180 MJ/microg, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule and produce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam. In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, the author estimates that ∼10 12 antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver

Fabrication and Characterization of ZnS/Diamond-Like Carbon Core-Shell Nanowires

Directory of Open Access Journals (Sweden)

Jung Han Kim

2016-01-01

Full Text Available We fabricated ZnS/diamond-like carbon (DLC core-shell heterostructure nanowire using a simple two-step process: the vapor-liquid-solid method combined with radio frequency plasma enhanced chemical vapor deposition (rf PECVD. As a core nanowire, ZnS nanowires with face-centered cubic structure were synthesized with a sputtered Au thin film, which exhibit a length and a diameter of ~10 μm and ~30–120 nm . After rf PECVD for DLC coating, The length and width of the dense ZnS/DLC core-shell nanowires were a range of ~10 μm  and 50–150 nm , respectively. In addition, ZnS/DLC core-shell nanowires were characterized with scanning transmission electron microscopy. From the results, the products have flat and uniform DLC coating layer on ZnS nanowire in spite of high residual stress induced by the high sp3 fraction. To further understanding of the DLC coating layer, Raman spectroscopy was employed with ZnS/DLC core-shell nanowires, which reveals two Raman bands at 1550 cm−1 (G peak and 1330 cm−1 (D peak. Finally, we investigated the optical properties from ultraviolet to infrared wavelength region using ultraviolet-visible (UV-Vis and Fourier transform infrared (FT-IR spectrometry. Related to optical properties, ZnS/DLC core-shell nanowires exhibit relatively lower absorbance and higher IR transmittance than that of ZnS nanowires.

Double-detonation model of type Ia supernovae with a variable helium layer ignition mass

International Nuclear Information System (INIS)

Zhou Wei-Hong; Zhao Gang; Wang Bo

2014-01-01

Although Type Ia supernovae (SNe Ia) play an important role in the study of cosmology, their progenitors are still poorly understood. Thermonuclear explosions from the helium double-detonation sub-Chandrasekhar mass model have been considered as an alternative method for producing SNe Ia. By adopting the assumption that a double detonation occurs when a He layer with a critical ignition mass accumulates on the surface of a carbon—oxygen white dwarf (CO WD), we perform detailed binary evolution calculations for the He double-detonation model, in which a He layer from a He star accumulates on a CO WD. According to these calculations, we obtain the initial parameter spaces for SNe Ia in the orbital period and secondary mass plane for various initial WD masses. We implement these results into a detailed binary population synthesis approach to calculate SN Ia birthrates and delay times. From this model, the SN Ia birthrate in our Galaxy is ∼0.4 − 1.6 × 10 −3 yr −1 . This indicates that the double-detonation model only produces part of the SNe Ia. The delay times from this model are ∼ 70 – 710 Myr, which contribute to the young population of SNe Ia in the observations. We found that the CO WD + sdB star system CD–30 11223 could produce an SN Ia via the double-detonation model in its future evolution. (research papers)

Structural acceptance criteria for the evaulation of existing double-shell waste storage tanks located at the Hanford site, Richland, Washington

International Nuclear Information System (INIS)

Julyk, L.J.; Day, A.D.; Dyrness, A.D.; Moore, C.J.; Peterson, W.S.; Scott, M.A.; Shrivastava, H.P.; Sholman, J.S.; Watts, T.N.

1995-09-01

The structural acceptance criteria contained herein for the evaluation of existing underground double-shell waste storage tanks located at the Hanford Site is part of the Life Management/Aging Management Program of the Tank Waste Remediation System. The purpose of the overall life management program is to ensure that confinement of the waste is maintained over the required service life of the tanks. Characterization of the present condition of the tanks, understanding and characterization of potential degradation mechanisms, and development of tank structural acceptance criteria based on previous service and projected use are prerequisites to assessing tank integrity, to projecting the length of tank service, and to developing and applying prudent fixes or repairs. The criteria provided herein summarize the requirements for the analysis and structural qualification of the existing double-shell tanks for continued operation. Code reconciliation issues and material degradation under aging conditions are addressed. Although the criteria were developed for double-shell tanks, many of the provisions are equally applicable to single-shell tanks. However, the criteria do not apply to the evaluation of tank appurtenances and buried piping

Soil structure interaction analysis for the Hanford Site 241-SY-101 double-shell waste storage tanks

International Nuclear Information System (INIS)

Giller, R.A.; Weiner, E.O.

1991-09-01

The 241-SY-101 tank is a double-shell waste storage tank buried in the 241-SY tank farm in the 200 West Area of the Hanford Site. This analysis addresses the effects of seismic soil-structure interaction on the tank structure and includes a parametric soil-structure interaction study addressing three configurations: two-dimensional soil structure, a two-dimensional structure-soil-structure, and a three-dimensional soil-structure interaction. This study was designed to determine an optimal method for addressing seismic-soil effects on underground storage tanks. The computer programs calculate seismic-soil pressures on the double-shell tank walls and and seismic acceleration response spectra in the tank. The results of this soil-structure interaction parametric study as produced by the computer programs are given in terms of seismic soil pressures and response spectra. The conclusions of this soil-structure interaction evaluation are that dynamically calculated soil pressures in the 241-SY-101 tank are significantly reduce from those using standard hand calculation methods and that seismic evaluation of underground double-shell waste storage tanks must consider soil-structure interaction effects in order to predict conservative structural response. Appendixes supporting this study are available in Volume 2 of this report

Ray convergence in a flux-like propagation formulation.

Science.gov (United States)

Harrison, Chris H

2013-06-01

The energy flux formulation of waveguide propagation is closely related to the incoherent mode sum, and its simplicity has led to development of efficient computational algorithms for reverberation and target echo strength, but it lacks the effects of convergence or modal interference. By starting with the coherent mode sum and rejecting the most rapid interference but retaining beats on a scale of a ray cycle distance it is shown that convergence can be included in a hybrid formulation requiring minimal extra computation. Three solutions are offered by evaluating the modal intensity cross terms using Taylor expansions. In the most efficient approach the double summation of the cross terms is reduced to a single numerical sum by solving the other summation analytically. The other two solutions are a local range average and a local depth average. Favorable comparisons are made between these three solutions and the wave model Orca with, and without, spatial averaging in an upward refracting duct. As a by-product, it is shown that the running range average is very close to the mode solution excluding its fringes, given a relation between averaging window size and effective number of modes which, in turn, is related to the waveguide invariant.

Use of d-3He proton spectroscopy as a diagnostic of shell rho r in capsule implosion experiments with approximately 0.2 NIF scale high temperature Hohlraums at Omega.

Science.gov (United States)

Delamater, N D; Wilson, D C; Kyrala, G A; Seifter, A; Hoffman, N M; Dodd, E; Singleton, R; Glebov, V; Stoeckl, C; Li, C K; Petrasso, R; Frenje, J

2008-10-01

We present the calculations and preliminary results from experiments on the Omega laser facility using d-(3)He filled plastic capsule implosions in gold Hohlraums. These experiments aim to develop a technique to measure shell rho r and capsule unablated mass with proton spectroscopy and will be applied to future National Ignition Facility (NIF) experiments with ignition scale capsules. The Omega Hohlraums are 1900 microm length x 1200 microm diameter and have a 70% laser entrance hole. This is approximately a 0.2 NIF scale ignition Hohlraum and reaches temperatures of 265-275 eV similar to those during the peak of the NIF drive. These capsules can be used as a diagnostic of shell rho r, since the d-(3)He gas fill produces 14.7 MeV protons in the implosion, which escape through the shell and produce a proton spectrum that depends on the integrated rho r of the remaining shell mass. The neutron yield, proton yield, and spectra change with capsule shell thickness as the unablated mass or remaining capsule rho r changes. Proton stopping models are used to infer shell unablated mass and shell rho r from the proton spectra measured with different filter thicknesses. The experiment is well modeled with respect to Hohlraum energetics, neutron yields, and x-ray imploded core image size, but there are discrepancies between the observed and simulated proton spectra.

Resonant Electron capture for be-like ions with K- and L- shell excitations

International Nuclear Information System (INIS)

Hanafy, H.

2005-01-01

Resonant electron capture in electron-ion collisions is known as dielectronic recombination (DR). It was proved that, DR dominants usually over radiative recombination (RR) at high energy. Since 1980's, DR is considered a very important process in thermal plasma. The DR is an effective process in self-cooling and ionization balance as well as plasma modeling. Experimental works are still carried out to understand the trends of DR process. In the present work, DR cross sections are calculated for Be-like ions with K- and L- shell excitations. It is found that, DR cross sections increase as the effective charge (Zeff) increases for both types of excitations. DR rates coefficient in case of L-shell excitation is found to be five times larger than that of K-shell excitation

Point-like structure and off-shell dual strings

International Nuclear Information System (INIS)

Green, M.B.

1977-01-01

It is argued that in a consistent off-shell dual formalism the amplitude for the emission of a scalar off-shell state by a string consists of two components. One of these contains the particle poles in the off-shell leg and the other is intimately related to the insertion of a point-like energy density on the string. As a result, the amplitude for a string to emit a zero momentum scalar state into the vacuum (which may be relevant for spontaneous symmetry breaking) is described by the amplitude for a finite fraction of the energy in the string to collapse to a spatial point at some time (this fraction and its space-time position being integrated over). The off-shell amplitudes have an elegant formulation in terms of a set of 'confined modes' which can be assigned quark flavour quantum numbers to reproduce the Chan-Paton scheme. It is suggested that the dual model be modified by allowing for the coupling of scalar closed strings to the vacuum and the resulting effect on the space-time structure of dual Green functions is described. It is found that even the emission of a single zero-momentum closed string modifies the elastic amplitude in a significant manner, leading to a power-behaved fixed-angle cross section in contrast to the usual exponential decrease of the dual model. This arises from point-like scattering between energy densities accumulating in the colliding strings. The relationship between the fixed angle and Regge limits is discussed. The fixed angle behaviour is found to be the asymptotic limit in momentum transfer of a fixed pole that arises in the Regge limit. (Auth.)

ELECTROCHEMICAL STUDIES OF CARBON STEEL CORROSION IN HANFORD DOUBLE SHELL TANK (DST) WASTE

Energy Technology Data Exchange (ETDEWEB)

DUNCAN, J.B.; WINDISCH, C.F.

2006-10-13

This paper reports on the electrochemical scans for the supernatant of Hanford double-shell tank (DST) 241-SY-102 and the electrochemical scans for the bottom saltcake layer for Hanford DST 241-AZ-102. It further reports on the development of electrochemical test cells adapted to both sample volume and hot cell constraints.

Pulse heating and ignition for off-centre ignited targets

International Nuclear Information System (INIS)

Mahdy, A.I.; Takabe, H.; Mima, K.

1999-01-01

An off-centre ignition model has been used to study the ignition conditions for laser targets related to the fast ignition scheme. A 2-D hydrodynamic code has been used, including alpha particle heating. The main goal of the study is the possibility of obtaining a high gain ICF target with fast ignition. In order to determine the ignition conditions, samples with various compressed core densities having different spark density-radius product (i.e. areal density) values were selected. The study was carried out in the presence of an external heating source, with a constant heating rate. A dependence of the ignition conditions on the heating rate of the external pulse is demonstrated. For a given set of ignition conditions, our simulation showed that an 11 ps pulse with 17 kJ of injected energy into the spark area was required to achieve ignition for a compressed core with a density of 200 g/cm 3 and 0.5 g/cm 2 spark areal density. It is shown that the ignition conditions are highly dependent on the heating rate of the external pulse. (author)

Tank characterization report for double-shell tank 241-AP-105

International Nuclear Information System (INIS)

DeLorenzo, D.S.; Simpson, B.C.

1994-01-01

Double-Shell Tank 241-AP-105 is a radioactive waste tank most recently sampled in March of 1993. Sampling and characterization of the waste in Tank 241-AP-105 contributes toward the fulfillment of Milestone M-44-05 of the Hanford Federal Facility Agreement and Consent Order (Ecology, EPA, and DOE, 1993). Characterization is also needed tot evaluate the waste's fitness for safe processing through an evaporator as part of an overall waste volume reduction program. Tank 241-AP-105, located in the 200 East Area AP Tank Farm, was constructed and went into service in 1986 as a dilute waste receiver tank; Tank 241AP-1 05 was considered as a candidate tank for the Grout Treatment Facility. With the cancellation of the Grout Program, the final disposal of the waste in will be as high- and low-level glass fractions. The tank has an operational capacity of 1,140,000 gallons, and currently contains 821,000 gallons of double-shell slurry feed. The waste is heterogeneous, although distinct layers do not exist. Waste has been removed periodically for processing and concentration through the 242-A Evaporator. The tank is not classified as a Watch List tank and is considered to be sound. There are no Unreviewed Safety Questions associated with Tank 241-AP-105 at this time. The waste in Tank 241-AP-105 exists as an aqueous solution of metallic salts and radionuclides, with limited amounts of organic complexants. The most prevalent soluble analytes include aluminum, potassium, sodium, hydroxide, carbonate, nitrate, and nitrite. The calculated pH is greater than the Resource Conservation and Recovery Act established limit of 12.5 for corrosivity. In addition, cadmium, chromium, and lead concentrations were found at levels greater than their regulatory thresholds. The major radionuclide constituent is 137 Cs, while the few organic complexants present include glycolate and oxalate. Approximately 60% of the waste by weight is water

Probability of ignition - a better approach than ignition margin

International Nuclear Information System (INIS)

Ho, S.K.; Perkins, L.J.

1989-01-01

The use of a figure of merit - the probability of ignition - is proposed for the characterization of the ignition performance of projected ignition tokamaks. Monte Carlo and analytic models have been developed to compute the uncertainty distribution function for ignition of a given tokamak design, in terms of the uncertainties inherent in the tokamak physics database. A sample analysis with this method indicates that the risks of not achieving ignition may be unacceptably high unless the accepted margins for ignition are increased. (author). Letter-to-the-editor. 12 refs, 2 figs, 2 tabs

Double Shell Tank (DST) Transfer Pump Subsystem Specification

International Nuclear Information System (INIS)

LESHIKAR, G.A.

2000-01-01

This specification establishes the performance requirements and provides references to the requisite codes and standards to be applied to the Double-Shell Tank (DST) Transfer Pump Subsystem which supports the first phase of Waste Feed Delivery (WFD). This specification establishes the performance requirements and provides the references to the requisite codes and standards to be applied during the design of the DST Transfer Pump Subsystem that supports the first phase of (WFD). The DST Transfer Pump Subsystem consists of a pump for supernatant and or slurry transfer for the DSTs that will be retrieved during the Phase 1 WFD operations. This system is used to transfer low-activity waste (LAW) and high-level waste (HLW) to designated DST staging tanks. It also will deliver blended LAW and HLW feed from these staging tanks to the River Protection Project (RPP) Privatization Contractor facility where it will be processed into an immobilized waste form. This specification is intended to be the basis for new projects/installations (W-521, etc.). This specification is not intended to retroactively affect previously established project design criteria without specific direction by the program

Inertial confinement fusion: steady progress towards ignition and high gain (summary talk)

International Nuclear Information System (INIS)

Basko, M.M.

2005-01-01

Based on the results presented at the 20th IAEA Fusion Energy Conference 2004, this paper highlights the most important recent advances in inertial confinement fusion (ICF). With the construction of the National Ignition Facility (NIF) and the Laser Megajoule facility and many improvements in the target design, the conventional indirect-drive approach is advancing steadily towards the demonstration of ignition and high gain. The development of the polar direct-drive concept also made the prospects for direct-drive ignition on the NIF very favourable. Substantial progress was reported on the exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at the lowest possible cost. In heavy-ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (E i ≥ 0.5 GeV u -1 ) heavy ions, has been proposed

Inertial confinement fusion: steady progress towards ignition and high gain (summary talk)

Science.gov (United States)

Basko, M. M.

2005-10-01

Based on the results presented at the 20th IAEA Fusion Energy Conference 2004, this paper highlights the most important recent advances in inertial confinement fusion (ICF). With the construction of the National Ignition Facility (NIF) and the Laser Mégajoule facility and many improvements in the target design, the conventional indirect-drive approach is advancing steadily towards the demonstration of ignition and high gain. The development of the polar direct-drive concept also made the prospects for direct-drive ignition on the NIF very favourable. Substantial progress was reported on the exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at the lowest possible cost. In heavy-ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (Ei>~ 0.5 GeV u-1) heavy ions, has been proposed.

Ignition and burn in contaminated DT fuel at high densities

International Nuclear Information System (INIS)

Pasley, J.

2010-01-01

Complete text of publication follows. Radiation hydrodynamics simulations have been performed to quantify the effect of contamination upon the ignition threshold in DT at high densities. A detailed thermonuclear burn model, with multi-group multispecies ions, is incorporated alongside a multigroup diffusion approximation for thermal radiation transport. The code used is the research version of the HYADES 1D code. Acceptable levels of contamination are identified for a range of contaminant ion species. A range of different contaminant spatial distribution within the fuel are explored: i) in which the contamination is uniformly distributed throughout the fuel; ii) in which the impurity ions are confined to the hotspot, or iii) where contamination is restricted to a particular region of the hotspot (either centrally, near the surface, or at an intermediate location). Initially the fuel has a constant density with the hotspot located centrally. The overall radius of the fuel is chosen to be sufficiently large that it has no significant effect upon the success or failure of ignition. The evolution of the system is then simulated until ignition either establishes widespread thermonuclear burning, or a failure to ignite is observed. The critical ρr for ignition is found by iteration on the hotspot radius. We show that varying the spatial distribution of the contaminant within the ignition spot has little effect, so long as the total mass of contaminant is held the same. As expected, high-Z contamination is far more detrimental than that by low-Z ions. Discussion of the findings in the context of re-entrant cone-guided fast ignition is presented, in addition to a theoretical interpretation of the results.

Energy convergence of shock waves and its destruction mechanism in cone-roof combustion chambers

International Nuclear Information System (INIS)

Xu, Han; Yao, Anren; Yao, Chunde; Gao, Jian

2016-01-01

Highlights: • Experiments with simulations are designed to probe into engine severe knock. • Energy convergence at central and edge region is observed in closed-limited space. • Modes with different intensities and mechanism of energy convergence are revealed. • Chamber shape and equivalence ratio can affect the energy convergence. • The destruction effects of energy convergence on pistons are recognized. - Abstract: Energy convergence is considered as an important phenomenon in internal combustion engines under severe knock, in which shock waves caused by violent combustion may aggregate the energy released by fuel burning to damage engine parts like pistons and spark plugs easily. In order to reveal such convergence mechanism and its destruction effects, a novel detonation bomb experiment combined with numerical simulations are conducted. In bomb experiments, a detonation wave is forcibly introduced into a clearance-variable cone-roof combustion chamber by a high energy spark ignition. Four pressure transducers were installed in different positions to monitor the energy convergence. Combined with the experiments, numerical simulations were conducted to reveal the convergence modes and mechanisms. Finally, destruction samples were presented to validate this research. It’s found that the energy convergence of shock waves always occurs in middle and edge region, which are vulnerable to be damaged. Three modes of energy convergence are concluded for middle region while several ways of energy convergence are concluded for edge region, which are all related with the chamber shape and may result in different levels of convergence. It’s also found that though detonation strength (knock intensity) can be changed by both equivalence ratios and initial pressures, only the equivalence ratios can change the convergence modes while the initial pressures cannot.

Design of Ultra High Performance Fiber Reinforced Concrete Shells

DEFF Research Database (Denmark)

Jepsen, Michael S.; Lambertsen, Søren Heide; Damkilde, Lars

2013-01-01

Fiber Reinforced Concrete shell. The major challenge in the design phase has been securing sufficient stiffness of the structure while keeping the weight at a minimum. The weight/stiffness issue has been investigated by means of the finite element method, to optimize the structure regarding overall......The paper treats the redesign of the float structure of the Wavestar wave energy converter. Previously it was designed as a glass fiber structure, but due to cost reduction requirements a redesign has been initiated. The new float structure will be designed as a double curved Ultra High Performance...

Ignition dynamics and activation energies of metallic thermites: From nano- to micron-scale particulate composites

Science.gov (United States)

Hunt, Emily M.; Pantoya, Michelle L.

2005-08-01

Ignition behaviors associated with nano- and micron-scale particulate composite thermites were studied experimentally and modeled theoretically. The experimental analysis utilized a CO2 laser ignition apparatus to ignite the front surface of compacted nickel (Ni) and aluminum (Al) pellets at varying heating rates. Ignition delay time and ignition temperature as a function of both Ni and Al particle size were measured using high-speed imaging and microthermocouples. The apparent activation energy was determined from this data using a Kissinger isoconversion method. This study shows that the activation energy is significantly lower for nano- compared with micron-scale particulate media (i.e., as low as 17.4 compared with 162.5kJ /mol, respectively). Two separate Arrhenius-type mathematical models were developed that describe ignition in the nano- and the micron-composite thermites. The micron-composite model is based on a heat balance while the nanocomposite model incorporates the energy of phase transformation in the alumina shell theorized to be an initiating step in the solid-solid diffusion reaction and uniquely appreciable in nanoparticle media. These models were found to describe the ignition of the Ni /Al alloy for a wide range of heating rates.

Inertial Confinement Fusion: steady progress towards ignition and high gain (summary talk)

International Nuclear Information System (INIS)

Basko, M.M.

2005-01-01

Most important recent advances in inertial confinement fusion (ICF) are highlighted. With the construction of the NIF and LMJ facilities, and a number of improvements in the target design, the conventional indirect-drive approach is making a steady progress towards demonstration of ignition and high gain. The development of the polar direct-drive concept made also the prospects for direct-drive ignition on the NIF extremely favorable. A substantial progress has been reported from the Institute of Laser Engineering in Osaka on exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at a lowest possible cost. In heavy ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (E i > or ∼ 0.5 GeV/u) heavy ions, has been proposed. (author)

Evolution between self-assembled single and double ring-like nanostructures

International Nuclear Information System (INIS)

Lee, J H; Wang, Zh M; Abuwaar, Z Y; Strom, N W; Salamo, G J

2006-01-01

The evolution between lattice-matched GaAs/Al 0.3 Ga 0.7 As single and double ring-like nanostructures is studied, with an emphasis on the construction and destruction of the observed outer ring. Using droplet epitaxy, this was achieved by directly controlling the Ga surface diffusion on GaAs(100). Double ring-like nanostructures were observed at relatively low temperatures under a fixed As 4 flux (beam equivalent pressure (BEP) of 6.4 μTorr) and at a fixed temperature under a high As 4 flux. The construction of the outer ring can be controlled through surface diffusion by varying the substrate temperature or the As 4 flux. Single ring-like nanostructures were realized both at relatively high temperatures under a fixed As 4 flux, and at low temperatures under a relatively low As 4 flux

A novel durable double-conductive core-shell structure applying to the synthesis of silicon anode for lithium ion batteries

Science.gov (United States)

Xing, Yan; Shen, Tong; Guo, Ting; Wang, Xiuli; Xia, Xinhui; Gu, Changdong; Tu, Jiangping

2018-04-01

Si/C composites are currently the most commercially viable next-generation lithium-ion battery anode materials due to their high specific capacity. However, there are still many obstacles need to be overcome such as short cycle life and poor conductivity. In this work, we design and successfully synthesis an excellent durable double-conductive core-shell structure p-Si-Ag/C composites. Interestingly, this well-designed structure offers remarkable conductivity (both internal and external) due to the introduction of silver particles and carbon layer. The carbon layer acts as a protective layer to maintain the integrity of the structure as well as avoids the direct contact of silicon with electrolyte. As a result, the durable double-conductive core-shell structure p-Si-Ag/C composites exhibit outstanding cycling stability of roughly 1000 mAh g-1 after 200 cycles at a current density of 0.2 A g-1 and retain 765 mAh g-1 even at a high current density of 2 A g-1, indicating a great improvement in electrochemical performance compared with traditional silicon electrode. Our research results provide a novel pathway for production of high-performance Si-based anodes to extending the cycle life and specific capacity of commercial lithium ion batteries.

Decision analysis for mobilizing and retrieving sludge from double-shell tanks

International Nuclear Information System (INIS)

Brothers, A.J.; Williams, N.C.; Dukelow, J.S.; Hansen, R.I.

1997-09-01

This decision analysis evaluates alternative technologies for the initial mobilization and retrieval of sludges in double-shell tanks (DSTs). The analysis is from the perspective of the need to move sludges from one DST to another for interim retrieval. It supports the more general decision of which technologies to use to retreive various types of DST waste. The initial analysis is from the perspective of a typical DST with 2 ft of sludge to mobilize. During the course of the analysis, it became clear that it was important to also consider sludge mobilization in support of the high-level waste (HLW) vitrification demonstration plant, and in particular the risks associated with failing to meeting the minimum order requirements for the vendor, as well as the cost of mobilization and retrieval from the HLW vitrification source tanks

Ignition on the National Ignition Facility: a path towards inertial fusion energy

International Nuclear Information System (INIS)

Moses, Edward I.

2009-01-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Ignition on the National Ignition Facility: a path towards inertial fusion energy

Science.gov (United States)

Moses, Edward I.

2009-10-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Bird's nest-like nanographene shell encapsulated Si nanoparticles - Their structural and Li anode properties

Science.gov (United States)

Li, Beibei; Jiang, Yizhe; Jiang, Fan; Cao, Daxian; Wang, Hongkang; Niu, Chunming

2017-02-01

Bird's nest-like nanographene shell (NGS) encapsulated Si@SiO2 nanoparticles have been prepared by a simple chemical vapor deposition (CVD) method. The shell is comprised of a conformed coating with 4-10 layers of the nanographene, and nanographene spikes with the same thickness grown on the coating surface. The high crystallinity of the shell is demonstrated by XRD, HRTEM and Raman characterization. After SiO2 has been removed, distinctive void space is created between Si core and nested NGS. Statistical estimation from TEM images of 50 Si@void@NGS particles shows that the volume of void space is about 2.82 times of that of Si nanoparticle, sufficient to accommodate volume change from Si to Li15Si4. Evaluation of Si@void@NGS for Li ion anode reveals a specific capacity of 2634 mAh g-1 at a current density of 0.2 A g-1, and an excellent rate and cycling performance. The capacity decreases by 5.2%-2497 mAh g-1 after cycling at current densities of 0.5, 1, 2, 5 10, 20 A g-1. The excellent performance can be attributed to high conductivity and high stability of the shell, which remains intact after repeated cycling.

Fast ignition realization experiment with high-contrast kilo-joule peta-watt LFEX laser and strong external magnetic field

Science.gov (United States)

Fujioka, Shinsuke; Arikawa, Yasunobu; Kojima, Sadaoki; Johzaki, Tomoyuki; Nagatomo, Hideo; Sawada, Hiroshi; Lee, Seung Ho; Shiroto, Takashi; Ohnishi, Naofumi; Morace, Alessio; Vaisseau, Xavier; Sakata, Shohei; Abe, Yuki; Matsuo, Kazuki; Farley Law, King Fai; Tosaki, Shota; Yogo, Akifumi; Shigemori, Keisuke; Hironaka, Yoichiro; Zhang, Zhe; Sunahara, Atsushi; Ozaki, Tetsuo; Sakagami, Hitoshi; Mima, Kunioki; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki; Kawanaka, Junji; Jitsuno, Takahisa; Miyanaga, Noriaki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Kondo, Kotaro; Bailly-Grandvaux, Mathieu; Bellei, Claudio; Santos, João Jorge; Azechi, Hiroshi

2016-05-01

A petawatt laser for fast ignition experiments (LFEX) laser system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 laser beams, has been constructed beside the GEKKO-XII laser facility for demonstrating efficient fast heating of a dense plasma up to the ignition temperature under the auspices of the Fast Ignition Realization EXperiment (FIREX) project [H. Azechi et al., Nucl. Fusion 49, 104024 (2009)]. In the FIREX experiment, a cone is attached to a spherical target containing a fuel to prevent a corona plasma from entering the path of the intense heating LFEX laser beams. The LFEX laser beams are focused at the tip of the cone to generate a relativistic electron beam (REB), which heats a dense fuel core generated by compression of a spherical deuterized plastic target induced by the GEKKO-XII laser beams. Recent studies indicate that the current heating efficiency is only 0.4%, and three requirements to achieve higher efficiency of the fast ignition (FI) scheme with the current GEKKO and LFEX systems have been identified: (i) reduction of the high energy tail of the REB; (ii) formation of a fuel core with high areal density using a limited number (twelve) of GEKKO-XII laser beams as well as a limited energy (4 kJ of 0.53-μm light in a 1.3 ns pulse); (iii) guiding and focusing of the REB to the fuel core. Laser-plasma interactions in a long-scale plasma generate electrons that are too energetic to efficiently heat the fuel core. Three actions were taken to meet the first requirement. First, the intensity contrast of the foot pulses to the main pulses of the LFEX was improved to >109. Second, a 5.5-mm-long cone was introduced to reduce pre-heating of the inner cone wall caused by illumination of the unconverted 1.053-μm light of implosion beam (GEKKO-XII). Third, the outside of the cone wall was coated with a 40-μm plastic layer to protect it from the pressure caused by imploding

Fast ignition realization experiment with high-contrast kilo-joule peta-watt LFEX laser and strong external magnetic field

Energy Technology Data Exchange (ETDEWEB)

Fujioka, Shinsuke, E-mail: sfujioka@ile.osaka-u.ac.jp; Arikawa, Yasunobu; Kojima, Sadaoki; Nagatomo, Hideo; Lee, Seung Ho; Morace, Alessio; Vaisseau, Xavier; Sakata, Shohei; Abe, Yuki; Matsuo, Kazuki; Farley Law, King Fai; Tosaki, Shota; Yogo, Akifumi; Shigemori, Keisuke; Hironaka, Yoichiro; Fujimoto, Yasushi; Yamanoi, Kohei; Norimatsu, Takayoshi; Tokita, Shigeki; Nakata, Yoshiki [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871 Japan (Japan); and others

2016-05-15

A petawatt laser for fast ignition experiments (LFEX) laser system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 laser beams, has been constructed beside the GEKKO-XII laser facility for demonstrating efficient fast heating of a dense plasma up to the ignition temperature under the auspices of the Fast Ignition Realization EXperiment (FIREX) project [H. Azechi et al., Nucl. Fusion 49, 104024 (2009)]. In the FIREX experiment, a cone is attached to a spherical target containing a fuel to prevent a corona plasma from entering the path of the intense heating LFEX laser beams. The LFEX laser beams are focused at the tip of the cone to generate a relativistic electron beam (REB), which heats a dense fuel core generated by compression of a spherical deuterized plastic target induced by the GEKKO-XII laser beams. Recent studies indicate that the current heating efficiency is only 0.4%, and three requirements to achieve higher efficiency of the fast ignition (FI) scheme with the current GEKKO and LFEX systems have been identified: (i) reduction of the high energy tail of the REB; (ii) formation of a fuel core with high areal density using a limited number (twelve) of GEKKO-XII laser beams as well as a limited energy (4 kJ of 0.53-μm light in a 1.3 ns pulse); (iii) guiding and focusing of the REB to the fuel core. Laser–plasma interactions in a long-scale plasma generate electrons that are too energetic to efficiently heat the fuel core. Three actions were taken to meet the first requirement. First, the intensity contrast of the foot pulses to the main pulses of the LFEX was improved to >10{sup 9}. Second, a 5.5-mm-long cone was introduced to reduce pre-heating of the inner cone wall caused by illumination of the unconverted 1.053-μm light of implosion beam (GEKKO-XII). Third, the outside of the cone wall was coated with a 40-μm plastic layer to protect it from the pressure caused

Structures of $p$-shell double-$\\Lambda$ hypernuclei studied with microscopic cluster models

OpenAIRE

Kanada-En'yo, Yoshiko

2018-01-01

$0s$-orbit $\\Lambda$ states in $p$-shell double-$\\Lambda$ hypernuclei ($^{\\ \\,A}_{\\Lambda\\Lambda}Z$), $^{\\ \\,8}_{\\Lambda\\Lambda}\\textrm{Li}$, $^{\\ \\,9}_{\\Lambda\\Lambda}\\textrm{Li}$, $^{10,11,12}_{\\ \\ \\ \\ \\ \\Lambda\\Lambda}\\textrm{Be}$, $^{12,13}_{\\ \\ \\Lambda\\Lambda}\\textrm{B}$, and $^{\\,14}_{\\Lambda\\Lambda}\\textrm{C}$ are investigated. Microscopic cluster models are applied to core nuclear part and a potential model is adopted for $\\Lambda$ particles. The $\\Lambda$-core potential is a folding ...

High-Performance Cryogenic Designs for OMEGA and the National Ignition Facility

Science.gov (United States)

Goncharov, V. N.; Collins, T. J. B.; Marozas, J. A.; Regan, S. P.; Betti, R.; Boehly, T. R.; Campbell, E. M.; Froula, D. H.; Igumenshchev, I. V.; McCrory, R. L.; Myatt, J. F.; Radha, P. B.; Sangster, T. C.; Shvydky, A.

2016-10-01

The main advantage of laser symmetric direct drive (SDD) is a significantly higher coupled drive laser energy to the hot-spot internal energy at stagnation compared to that of laser indirect drive. Because of coupling losses resulting from cross-beam energy transfer (CBET), however, reaching ignition conditions on the NIF with SDD requires designs with excessively large in-flight aspect ratios ( 30). Results of cryogenic implosions performed on OMEGA show that such designs are unstable to short-scale nonuniformity growth during shell implosion. Several CBET reduction strategies have been proposed in the past. This talk will discuss high-performing designs using several CBET-mitigation techniques, including using drive laser beams smaller than the target size and wavelength detuning. Designs that are predicted to reach alpha burning regimes as well as a gain of 10 to 40 at the NIF-scale will be presented. Hydrodynamically scaled OMEGA designs with similar CBET-reduction techniques will also be discussed. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Study of ignition in a high compression ratio SI (spark ignition) methanol engine using LES (large eddy simulation) with detailed chemical kinetics

International Nuclear Information System (INIS)

Zhen, Xudong; Wang, Yang

2013-01-01

Methanol has been recently used as an alternative to conventional fuels for internal combustion engines in order to satisfy some environmental and economical concerns. In this paper, the ignition in a high compression ratio SI (spark ignition) methanol engine was studied by using LES (large eddy simulation) with detailed chemical kinetics. A 21-species, 84-reaction methanol mechanism was adopted to simulate the auto-ignition process of the methanol/air mixture. The MIT (minimum ignition temperature) and MIE (minimum ignition energy) are two important properties for designing safety standards and understanding the ignition process of combustible mixtures. The effects of the flame kernel size, flame kernel temperature and equivalence ratio were also examined on MIT, MIE and IDP (ignition delay period). The methanol mechanism was validated by experimental test. The simulated results showed that the flame kernel size, temperature and energy dramatically affected the values of the MIT, MIE and IDP for a methanol/air mixture, the value of the ignition delay period was not only related to the flame kernel energy, but also to the flame kernel temperature. - Highlights: • We used LES (large eddy simulation) coupled with detailed chemical kinetics to simulate methanol ignition. • The flame kernel size and temperature affected the minimum ignition temperature. • The flame kernel temperature and energy affected the ignition delay period. • The equivalence ratio of methanol–air mixture affected the ignition delay period

THE EFFECT OF GASOLINE-LIKE FUEL PRODUCED FROM WASTE AUTOMOBILE TIRES ON EMISSIONS IN SPARK-IGNITION ENGINES

OpenAIRE

ÖZTOP, H. F.; VAROL, Y.; ALTUN, Ş.; FIRAT, M.

2016-01-01

In the present paper, the effect of Gasoline-Like Fuel (GLF) on emissions was investigated for direct injection spark-ignited engine. The GLF was obtained from waste automobile tires by using the pyrolysis. The tires are installed to oven without any procedure such as cutting, melding etc. Obtained GLF was then used in a four-cylinder, four-stroke, water-cooled and direct injection spark-ignited engine as blended with unleaded gasoline from 0% to 60% with an increment of 10%. Engine tests res...

8. High power laser and ignition facilities

International Nuclear Information System (INIS)

Bayramian, A.J.; Beach, R.J.; Bibeau, C.

2002-01-01

This document gives a review of the various high power laser projects and ignition facilities in the world: the Mercury laser system and Electra (Usa), the krypton fluoride (KrF) laser and the HALNA (high average power laser for nuclear-fusion application) project (Japan), the Shenguang series, the Xingguang facility and the TIL (technical integration line) facility (China), the Vulcan peta-watt interaction facility (UK), the Megajoule project and its feasibility phase: the LIL (laser integration line) facility (France), the Asterix IV/PALS high power laser facility (Czech Republic), and the Phelix project (Germany). In Japan the 100 TW Petawatt Module Laser, constructed in 1997, is being upgraded to the world biggest peta-watt laser. Experiments have been performed with single-pulse large aperture e-beam-pumped Garpun (Russia) and with high-current-density El-1 KrF laser installation (Russia) to investigate Al-Be foil transmittance and stability to multiple e-beam irradiations. An article is dedicated to a comparison of debris shield impacts for 2 experiments at NIF (national ignition facility). (A.C.)

Protein-assisted synthesis of double-shelled CaCO3 microcapsules and their mineralization with heavy metal ions.

Science.gov (United States)

Li, Xuan Qi; Feng, Zhiwei; Xia, Yinyan; Zeng, Hua Chun

2012-02-13

Calcium carbonate (CaCO(3)) is one of the most abundant and important biominerals in nature. Due to its biocompatibility, biodegradability and nontoxicity, CaCO(3) has been investigated extensively in recent years for various fundamental properties and technological applications. Inspired by basic wall structures of cells, we report a protein-assisted approach to synthesize CaCO(3) into a double-shelled structural configuration. Due to varying reactivities of outer and inner shells, the CaCO(3) microcapsules exhibit different sorption capacities and various resultant structures toward different kinds of heavy metal ions, analogical to biologically controlled mineralization (BCM) processes. Surprisingly, three mineralization modes resembling those found in BCM were found with these bacterium-like "CaCO(3) cells". Our investigation of the cytotoxicity (MTT assay protocol) also indicates that the CaCO(3) microcapsules have almost no cytotoxicity against HepG2 cells, and they might be useful for future application of detoxifying heavy metal ions after further study. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A hybrid concept (segmented plus monolithic fused silica shells) for a high-throughput and high-angular resolution x-ray mission (Lynx/X-Ray Surveyor like)

Science.gov (United States)

Basso, Stefano; Civitani, Marta; Pareschi, Giovanni; Parodi, Giancarlo

2017-09-01

Lynx is a large area and high angular resolution X-ray mission being studied by NASA to be presented to the next Decadal Survey for the implementation in the next decade. It aims to realize an X-ray telescope with the effective area similar to Athena (2 m2 at 1 keV) but with the same angular resolution of Chandra and a much larger Field Of View (up 20 arcmin x 20 arcmin). The science of X-ray Surveyor requires a large-throughput mirror assembly with sub-arcsec angular resolution. These future X-ray mirrors have a set of requirements which, collectively, represents very substantial advances over any currently in operation or planned for missions other than X-ray Surveyor. Of particular importance is achieving low mass per unit collecting area, while maintaining Chandra like angular resolution. Among the possible solutions under study, the direct polishing of both thin monolithic pseudo-cylindrical shells and segments made of fused silica are being considered as viable solutions for the implementation of the mirrors. Fused silica has very good thermomechanical parameters (including a very low CTE), making the material particularly well suited for for the production of the Lynx mirrors. It should be noted that the use of close shells is also very attractive, since the operations for the integration of the shells will be greatly simplified and the area lost due to the vignetting from the interfacing structures minimized even if the management of such big (diameter of 3 m) and thin shells have to be demonstrated. In this paper we will discuss a possible basic layout for a full shell mirror and a hybrid concept (segmented plus monolithic shells made of fused silica) as a second solution, for the Lynx/XRS telescope, discussing preliminary results in terms of optical and mechanical performance.

Hollow Pd/MOF Nanosphere with Double Shells as Multifunctional Catalyst for Hydrogenation Reaction.

Science.gov (United States)

Wan, Mingming; Zhang, Xinlu; Li, Meiyan; Chen, Bo; Yin, Jie; Jin, Haichao; Lin, Lin; Chen, Chao; Zhang, Ning

2017-10-01

A new type of hollow nanostructure featured double metal-organic frameworks shells with metal nanoparticles (MNPs) is designed and fabricated by the methods of ship in a bottle and bottle around the ship. The nanostructure material, hereinafter denoted as Void@HKUST-1/Pd@ZIF-8, is confirmed by the analyses of photograph, transmission electron microscopy, scanning electron microscopy, powder X-ray diffraction, inductively coupled plasma, and N 2 sorption. It possesses various multifunctionally structural characteristics such as hollow cavity which can improve mass transfer, the adjacent of the inner HKUST-1 shell to the void which enables the matrix of the shell to host and well disperse MNPs, and an outer ZIF-8 shell which acts as protective layer against the leaching of MNPs and a sieve to guarantee molecular-size selectivity. This makes the material eligible candidates for the heterogeneous catalyst. As a proof of concept, the liquid-phase hydrogenation of olefins with different molecular sizes as a model reaction is employed. It demonstrates the efficient catalytic activity and size-selectivity of Void@HKUST-1/Pd@ZIF-8. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simulations of laser imprint for Nova experiments and for ignition capsules. Revision 1

International Nuclear Information System (INIS)

Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Key, M.H.; Remington, B.A.; Rothenberg, J.L.; Wolfrum, E.; Verdon, C.P.; Knauer, J.P.

1996-12-01

In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called ''imprint''. These nonuniformities grow during the capsule implosion and, if initially large enough, can penetrate the capsule shell, impede ignition, or degrade burn. Imprint has been simulated for recent experiments performed on the Nova laser at LLNL examining a variety of beam smoothing conditions. Most used laser intensities similar to the early part of an ignition capsule pulse shape, 1 ≅ 10 13 W/cm 2 . The simulations matched most of the measurements of imprint modulation. The effect of imprint upon National Ignition Facility (NIF) direct drive ignition capsules has also been simulated. Imprint is predicted to give modulation comparable to an intrinsic surface finish of ∼10 nm RMS. Modulation growth was examined using the Haan [Phys. Rev. A 39, 5812 (1989)] model, with linear growth factors as a function of spherical harmonic mode number obtained from an analytic dispersion relation. Ablation front amplitudes are predicted to become substantially nonlinear, so that saturation corrections are large. Direct numerical simulations of two-dimensional multimode growth were also performed. The capsule shell is predicted to remain intact, which gives a basis for believing that ignition can be achieved. 27 refs., 10 figs

Vibrations of Thin Piezoelectric Shallow Shells

Indian Academy of Sciences (India)

Abstract. In this paper we consider the eigenvalue problem for piezoelectric shallow shells and we show that, as the thickness of the shell goes to zero, the eigensolutions of the three-dimensional piezoelectric shells converge to the eigensolutions of a two-dimensional eigenvalue problem.

f ( λ , μ $f_{(\\lambda,\\mu}$ -statistical convergence of order α̃ for double sequences

Directory of Open Access Journals (Sweden)

Mahmut Işik

2017-10-01

Full Text Available Abstract New concepts of f λ , μ $f_{\\lambda,\\mu }$ -statistical convergence for double sequences of order α̃ and strong f λ , μ $f_{\\lambda,\\mu }$ -Cesàro summability for double sequences of order α̃ are introduced for sequences of (complex or real numbers. Furthermore, we give the relationship between the spaces w α ˜ , 0 2 ( f , λ , μ $w_{\\tilde{\\alpha },0}^{2} ( f,\\lambda,\\mu $ , w α ˜ 2 ( f , λ , μ $w_{\\tilde{\\alpha }}^{2} ( f,\\lambda,\\mu $ and w α ˜ , ∞ 2 ( f , λ , μ $w_{\\tilde{\\alpha},\\infty }^{2} ( f,\\lambda,\\mu $ . Then we express the properties of strong f λ , μ $f_{\\lambda,\\mu }$ -Cesàro summability of order β̃ which is related to strong f λ , μ $f_{\\lambda,\\mu }$ -Cesàro summability of order α̃. Also, some relations between f λ , μ $f_{\\lambda,\\mu }$ -statistical convergence of order α̃ and strong f λ , μ $f_{\\lambda,\\mu }$ -Cesàro summability of order α̃ are given.

Ignition tuning for the National Ignition Campaign

Directory of Open Access Journals (Sweden)

Landen O.

2013-11-01

Full Text Available The overall goal of the indirect-drive inertial confinement fusion [1] tuning campaigns [2] is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics [3] used in our radiation-hydrodynamic computational models, and by checking for and resolving unexpected shot-to-shot variability in performance [4]. This has been started successfully using a variety of surrogate capsules that set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix.

A double patella-like condition secondary to synovial osteochondromatosis

Directory of Open Access Journals (Sweden)

Kajikawa Yoshiteru

2012-09-01

Full Text Available Abstract To our knowledge, this is the first case of synovial osteochondromatosis in a patient presenting with a double patella-like condition. The true duplication of the patella, which is called double patella, is extremely rare. In our case, the operative and histopathological findings showed that the double patella-like condition was secondarily induced by synovial osteochondromatosis. Synovial osteochondromatosis should be considered as a differential diagnosis for congenital double patella.

Durability of double-shell slurry feed grouts: FY-90 results

International Nuclear Information System (INIS)

Lokken, R.O.; Martin, P.F.C.

1992-12-01

Plans for disposal of the low-level fraction of selected double-shell tank wastes at Hanford include grouting. Grout disposal is the process of mixing low-level liquid waste with cementitious powders and pumping the slurry to near-surface, underground concrete vaults; hydration results in the formation of a solid product that binds/encapsulates the radioactive/hazardous constituents. In this durability program, previous studies have indicated a strong impact from curing temperature/time on strength and leach resistance of DSSF grouts. The current studies were expanded to determine whether these impacts could be attributed to other factors, such as dry blend composition and waste concentration. Major conclusions: grouts from dry blends with 40 wt% limestone had lower strengths; compressive strengths and leach resistance decreased with increased curing temperature/time; leach resistance increased for grouts prepared with dilute DSSF; nitrate leach resistance increased with high slag/cement ratios, dilute DSSF, and low curing temperatures; amount of drainable liquids for grouts using diluted DSSF was lowest when slag content was high; the 2 most significant factors affecting grout properties were the slag/cement ratio and waste dilution (slag-waste reactions appear to dominate the properties of DSSF grouts)

HANFORD DOUBLE-SHELL TANK THERMAL AND SEISMIC PROJECT-SENSITIVITY OF DOUBLE-SHELL DYNAMIC RESPONSE TO THE WASTE ELASTIC PROPERTIES

International Nuclear Information System (INIS)

Mackey, T.C.; Abatt, F.G.; Johnson, K.I.

2009-01-01

The purpose of this study was to determine the sensitivity of the dynamic response of the Hanford double-shell tanks (DSTs) to the assumptions regarding the constitutive properties of the contained waste. In all cases, the waste was modeled as a uniform linearly elastic material. The focus of the study was on the changes in the modal response of the tank and waste system as the extensional modulus (elastic modulus in tension and compression) and shear modulus of the waste were varied through six orders of magnitude. Time-history analyses were also performed for selected cases and peak horizontal reaction forces and axial stresses at the bottom of the primary tank were evaluated. Because the analysis focused on the differences in the responses between solid-filled and liquid-filled tanks, it is a comparative analysis rather than an analysis of record for a specific tank or set of tanks. The shear modulus was varied between 4 x 10 3 Pa and 4.135 x 10 9 Pa. The lowest value of shear modulus was sufficient to simulate the modal response of a liquid-containing tank, while the higher values are several orders of magnitude greater than the upper limit of expected properties for tank contents. The range of elastic properties used was sufficient to show liquid-like response at the lower values, followed by a transition range of semi-solid-like response to a clearly identifiable solid-like response. It was assumed that the mechanical properties of the tank contents were spatially uniform. Because sludge-like materials are expected only to exist in the lower part of the tanks, this assumption leads to an exaggeration of the effects of sludge-like materials in the tanks. The results of the study show that up to a waste shear modulus of at least 40,000 Pa, the modal properties of the tank and waste system are very nearly the same as for the equivalent liquid-containing tank. This suggests that the differences in critical tank responses between liquid-containing tanks and tanks

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SENSITIVITY OF DOUBLE SHELL DYNAMIC RESPONSE TO THE WASTE ELASTIC PROPERTIES

Energy Technology Data Exchange (ETDEWEB)

MACKEY TC; ABATT FG; JOHNSON KI

2009-01-16

The purpose of this study was to determine the sensitivity of the dynamic response of the Hanford double-shell tanks (DSTs) to the assumptions regarding the constitutive properties of the contained waste. In all cases, the waste was modeled as a uniform linearly elastic material. The focus of the study was on the changes in the modal response of the tank and waste system as the extensional modulus (elastic modulus in tension and compression) and shear modulus of the waste were varied through six orders of magnitude. Time-history analyses were also performed for selected cases and peak horizontal reaction forces and axial stresses at the bottom of the primary tank were evaluated. Because the analysis focused on the differences in the responses between solid-filled and liquid-filled tanks, it is a comparative analysis rather than an analysis of record for a specific tank or set of tanks. The shear modulus was varied between 4 x 10{sup 3} Pa and 4.135 x 10{sup 9} Pa. The lowest value of shear modulus was sufficient to simulate the modal response of a liquid-containing tank, while the higher values are several orders of magnitude greater than the upper limit of expected properties for tank contents. The range of elastic properties used was sufficient to show liquid-like response at the lower values, followed by a transition range of semi-solid-like response to a clearly identifiable solid-like response. It was assumed that the mechanical properties of the tank contents were spatially uniform. Because sludge-like materials are expected only to exist in the lower part of the tanks, this assumption leads to an exaggeration of the effects of sludge-like materials in the tanks. The results of the study show that up to a waste shear modulus of at least 40,000 Pa, the modal properties of the tank and waste system are very nearly the same as for the equivalent liquid-containing tank. This suggests that the differences in critical tank responses between liquid-containing tanks

Direct drive: Simulations and results from the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Radha, P. B., E-mail: rbah@lle.rochester.edu; Hohenberger, M.; Edgell, D. H.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Rosenberg, M. J.; Seka, W.; Shvydky, A.; Boehly, T. R.; Collins, T. J. B.; Campbell, E. M.; Craxton, R. S.; Delettrez, J. A.; Froula, D. H.; Goncharov, V. N.; Hu, S. X.; Knauer, J. P.; McCrory, R. L.; McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); and others

2016-05-15

Direct-drive implosion physics is being investigated at the National Ignition Facility. The primary goal of the experiments is twofold: to validate modeling related to implosion velocity and to estimate the magnitude of hot-electron preheat. Implosion experiments indicate that the energetics is well-modeled when cross-beam energy transfer (CBET) is included in the simulation and an overall multiplier to the CBET gain factor is employed; time-resolved scattered light and scattered-light spectra display the correct trends. Trajectories from backlit images are well modeled, although those from measured self-emission images indicate increased shell thickness and reduced shell density relative to simulations. Sensitivity analyses indicate that the most likely cause for the density reduction is nonuniformity growth seeded by laser imprint and not laser-energy coupling. Hot-electron preheat is at tolerable levels in the ongoing experiments, although it is expected to increase after the mitigation of CBET. Future work will include continued model validation, imprint measurements, and mitigation of CBET and hot-electron preheat.

Engineering Task Plan for the Ultrasonic Inspection of Hanford Double-Shell Tanks - FY 2001

International Nuclear Information System (INIS)

JENSEN, C.E.

2000-01-01

This document facilitates the ultrasonic examination of Hanford double-shell tanks. Included are a plan for engineering activities, plan for performance demonstration testing, and a plan for field activities. Also included are a Statement of Work for contractor performance and a protocol to be followed should tank flaws that exceed the acceptance criteria are found

The Richtmyer-Meshkov instability of a double-layer interface in convergent geometry with magnetohydrodynamics

KAUST Repository

Li, Yuan

2018-04-13

The interaction between a converging cylindrical shock and double density interfaces in the presence of a saddle magnetic field is numerically investigated within the framework of ideal magnetohydrodynamics. Three fluids of differing densities are initially separated by the two perturbed cylindrical interfaces. The initial incident converging shock is generated from a Riemann problem upstream of the first interface. The effect of the magnetic field on the instabilities is studied through varying the field strength. It shows that the Richtmyer-Meshkov and Rayleigh-Taylor instabilities are mitigated by the field, however, the extent of the suppression varies on the interface which leads to non-axisymmetric growth of the perturbations. The degree of asymmetry of the interfacial growth rate is increased when the seed field strength is increased.

The Richtmyer-Meshkov instability of a double-layer interface in convergent geometry with magnetohydrodynamics

KAUST Repository

Li, Yuan; Samtaney, Ravi; Wheatley, Vincent

2018-01-01

The interaction between a converging cylindrical shock and double density interfaces in the presence of a saddle magnetic field is numerically investigated within the framework of ideal magnetohydrodynamics. Three fluids of differing densities are initially separated by the two perturbed cylindrical interfaces. The initial incident converging shock is generated from a Riemann problem upstream of the first interface. The effect of the magnetic field on the instabilities is studied through varying the field strength. It shows that the Richtmyer-Meshkov and Rayleigh-Taylor instabilities are mitigated by the field, however, the extent of the suppression varies on the interface which leads to non-axisymmetric growth of the perturbations. The degree of asymmetry of the interfacial growth rate is increased when the seed field strength is increased.

Stakeholder involvement in redefining Hanford's Double-Shell Tank Waste Disposal Program

International Nuclear Information System (INIS)

Triplett, M.B.; Hunter, V.L.

1992-01-01

Hanford's Double-Shell Tank (DST) waste disposal strategy, outlined in the Final Environmental Impact Statement, Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes, Hanford Site, Richland, Washington calls for using B-Plant to separate the low-level and high-level portions of the DST waste. This separations step would provide feed to the Hanford Waste Vitrification Plant (HWVP), viewed by many as the cornerstone to Site cleanup. The State of Washington strongly opposed using the 47-year old B-Plant because it was not built to comply with current environmental regulations. Because of this and other challenges to Hanford's tank waste disposal strategy, the Department of Energy (DOE) Richland Field Office (RL) initiated efforts to redefine the strategy. To support this effort, Pacific Northwest Laboratory, (PNL) and Westinghouse Hanford Company, (WHC) and sought input from outside stakeholder (stakeholders are those interest groups that are affected by the outcome of the decision and have a strong desire to ensure that their concerns are addressed) groups through a formal stakeholder involvement and multiattribute utility (MAU) analysis process

Flammable gas double shell tank expert elicitation presentations (Part A and Part B)

Energy Technology Data Exchange (ETDEWEB)

Bratzel, D.R.

1998-04-17

This document is a compilation of presentation packages and white papers for the Flammable Gas Double Shell Tank Expert Elicitation Workshop {number_sign}2. For each presentation given by the different authors, a separate section was developed. The purpose for issuing these workshop presentation packages and white papers as a supporting document is to provide traceability and a Quality Assurance record for future reference to these packages.

Flammable gas double shell tank expert elicitation presentations (Part A and Part B)

International Nuclear Information System (INIS)

Bratzel, D.R.

1998-01-01

This document is a compilation of presentation packages and white papers for the Flammable Gas Double Shell Tank Expert Elicitation Workshop number-sign 2. For each presentation given by the different authors, a separate section was developed. The purpose for issuing these workshop presentation packages and white papers as a supporting document is to provide traceability and a Quality Assurance record for future reference to these packages

Some Double Sequence Spaces of Fuzzy Real Numbers of Paranormed Type

Directory of Open Access Journals (Sweden)

Bipul Sarma

2013-01-01

Full Text Available We study different properties of convergent, null, and bounded double sequence spaces of fuzzy real numbers like completeness, solidness, sequence algebra, symmetricity, convergence-free, and so forth. We prove some inclusion results too.

Modeling of high energy laser ignition of energetic materials

International Nuclear Information System (INIS)

Lee, Kyung-cheol; Kim, Ki-hong; Yoh, Jack J.

2008-01-01

We present a model for simulating high energy laser heating and ignition of confined energetic materials. The model considers the effect of irradiating a steel plate with long laser pulses and continuous lasers of several kilowatts and the thermal response of well-characterized high explosives for ignition. Since there is enough time for the thermal wave to propagate into the target and to create a region of hot spot in the high explosives, electron thermal diffusion of ultrashort (femto- and picosecond) lasing is ignored; instead, heat diffusion of absorbed laser energy in the solid target is modeled with thermal decomposition kinetic models of high explosives. Numerically simulated pulsed-laser heating of solid target and thermal explosion of cyclotrimethylenetrinitramine, triaminotrinitrobenzene, and octahydrotetranitrotetrazine are compared to experimental results. The experimental and numerical results are in good agreement

K-shell excitation studied for H- and He-like bismuth ions in collisions with low-z target atoms

International Nuclear Information System (INIS)

Stoehlker, T.; Bosch, F.; Geissel, H.; Kozhuharov, C.; Ludziejewski, T.; Mokler, P.H.; Scheidenberger, C.; Stachura, Z.; Warczak, A.

1997-09-01

The formation of excited projectile states via Coulomb excitation is investigated for hydrogen- and helium-like bismuth projectiles (Z=83) in relativistic ion-atom collisions. The excitation process was unambiguously identified by observing the radiative decay of the excited levels to the vacant 1s shell in coincidence with ions that did not undergo charge exchange in the reaction target. In particular, owing to the large fine structure splitting of Bi, the excitation cross-sections to the various L-shell sublevels are determined separately. The results are compared with detailed relativistic calculations, showing that both the relativistic character of the bound-state wave-functions and the magnetic interaction are of considerable importance for the K-shell excitation process in high-Z ions like Bi. The experimental data confirm the result of the complete relativistic calculations, namely that the magnetic part of the Lienard-Wiechert interaction leads to a significant reduction of the K-shell excitation cross-section. (orig.)

Tank characterization report for double-shell tank 241-AN-102

International Nuclear Information System (INIS)

Jo, J.

1996-01-01

This characterization report summarizes the available information on the historical uses, current status, and sampling and analysis results of waste stored in double-shell underground storage tank 241- AN-102. This report supports the requirements of the Hanford Federal Facility Agreement and Consent Order, Milestone M-44-09 (Ecology et al. 1996). Tank 241-AN-102 is one of seven double-shell tanks located in the AN Tank Farm in the Hanford Site 200 East Area. The tank was hydrotested in 1981, and when the water was removed, a 6-inch heel was left. Tank 241-AN-102 began receiving waste from tank 241-SY-102 beginning in 1982. The tank was nearly emptied in the third quarter of 1983, leaving only 125 kL (33 kgal) of waste. Between the fourth quarter of 1983 and the first quarter of 1984, tank 241-AN-102 received waste from tanks 241-AY-102, 241-SY-102, 241-AW-105, and 241- AN-101. The tank was nearly emptied in the second quarter of 1984, leaving a heel of 129 kL (34 kgal). During the second and third quarters of 1984, the tank was filled with concentrated complexant waste from tank 241-AW-101. Since that time, only minor amounts of Plutonium-Uranium Extraction (PUREX) Plant miscellaneous waste and water have been received; there have been no waste transfer to or from the tank since 1992. Therefore, the waste currently in the tank is considered to be concentrated complexant waste. Tank 241-AN-102 is sound and is not included on any of the Watch Lists

Diesel ignition delay and lift-off length through different methodologies using a multi-hole injector

International Nuclear Information System (INIS)

Payri, Raúl; Salvador, F.J.; Manin, Julien; Viera, Alberto

2016-01-01

Highlights: • Lift-off length and ignition delay are measured through different methodologies. • Oxygen concentration, temperature and injection pressure sweeps are performed. • A multi hole injector is compared with an equivalent single hole injector. • Multi hole injector has shorter ignition delay and lift-off length than single hole. • Empirical correlations were calculated for an analytical description of the results. - Abstract: In this paper, lift-off length has been measured via both broadband luminosity and OH chemiluminescence. In addition, ignition delay has also been measured via broadband chemiluminescence and Schlieren imaging. A 3 orifice injector from the Engine Combustion Network (ECN) set, referred to as Spray B, and a single component fuel (n-dodecane) was used. Experiments were carried out in a constant flow and pressure facility, that allowed to reproduce engine-like thermodynamic conditions, and enabled the study to be performed over a wide range of test conditions with a very high repetition rate. Data obtained was also compared with results from a single orifice injector also from the Engine Combustion Network, with analog orifice characteristics (90 μm outlet diameter and convergent shape) and technology as the injector used. Results showed that there is good correlation between the ignition delay measured through both methodologies, that oxygen concentration and injection pressure plays a minor role in the ignition delay, being ambient temperature and density the parameters with the highest influence. Lift-off length measurements showed significant differences between methodologies. Minor deviation was observed between injectors with different nozzle geometry (seat inclination angle), due to temperature variations along the chamber, highlighting the importance of temperature distribution along combustion vessels. Empirical correlations for lift-off and ignition delay were calculated, underlining the effect of the conditions on

Shock Tube Ignition Delay Data Affected by Localized Ignition Phenomena

KAUST Repository

Javed, Tamour

2016-12-29

Shock tubes have conventionally been used for measuring high-temperature ignition delay times ~ O(1 ms). In the last decade or so, the operating regime of shock tubes has been extended to lower temperatures by accessing longer observation times. Such measurements may potentially be affected by some non-ideal phenomena. The purpose of this work is to measure long ignition delay times for fuels exhibiting negative temperature coefficient (NTC) and to assess the impact of shock tube non-idealities on ignition delay data. Ignition delay times of n-heptane and n-hexane were measured over the temperature range of 650 – 1250 K and pressures near 1.5 atm. Driver gas tailoring and long length of shock tube driver section were utilized to measure ignition delay times as long as 32 ms. Measured ignition delay times agree with chemical kinetic models at high (> 1100 K) and low (< 700 K) temperatures. In the intermediate temperature range (700 – 1100 K), however, significant discrepancies are observed between the measurements and homogeneous ignition delay simulations. It is postulated, based on experimental observations, that localized ignition kernels could affect the ignition delay times at the intermediate temperatures, which lead to compression (and heating) of the bulk gas and result in expediting the overall ignition event. The postulate is validated through simple representative computational fluid dynamic simulations of post-shock gas mixtures which exhibit ignition advancement via a hot spot. The results of the current work show that ignition delay times measured by shock tubes may be affected by non-ideal phenomena for certain conditions of temperature, pressure and fuel reactivity. Care must, therefore, be exercised in using such data for chemical kinetic model development and validation.

References for HNF-SD-WM-TRD-007, ''System specification for the double-shell tank system: HNF-PROs, CFRs, DOE Orders, WACs''

International Nuclear Information System (INIS)

Shaw, C.P.

1998-01-01

HNF-SD-WM-TRD-O07, System Specification for the Double-Shell Tank System, (hereafter referred to as DST Specification), defines the requirements of the double-shell tank system at the Hanford Site for Phase 1 privatization. Many of the sections in this document reference other documents for design guidance and requirements. Referenced documents include Project Hanford Management Contract (PHMC) procedures (HNF-PROS), Codes of Federal Regulation (CFRs), DOE Orders, and Washington Administrative Codes (WACs). This document provides rationale for the selection and inclusion of HNF-PROS, CFRs, DOE Orders and WACs

Tank characterization report for double-shell Tank 241-AP-107

International Nuclear Information System (INIS)

DeLorenzo, D.S.; Simpson, B.C.

1994-01-01

The purpose of this tank characterization report is to describe and characterize the waste in Double-Shell Tank 241-AP-107 based on information gathered from various sources. This report summarizes the available information regarding the waste in Tank 241-AP-107, and arranges it in a useful format for making management and technical decisions concerning this particular waste tank. In addition, conclusion and recommendations based on safety and further characterization needs are given. Specific objectives reached by the sampling and characterization of the waste in Tank 241-AP-107 are: Contribute toward the fulfillment of the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) Milestone M-44-05 concerning the characterization of Hanford Site high-level radioactive waste tanks; Complete safety screening of the contents of Tank 241-AP-107 to meet the characterization requirements of the Defense Nuclear Facilities Safety board (DNFSB) Recommendation 93-5; and Provide tank waste characterization to the Tank Waste Remediation System (TWRS) Program Elements in accordance with the TWRS Tank Waste Analysis Plan

Broadband absorption and enhanced photothermal conversion property of octopod-like Ag@Ag2S core@shell structures with gradually varying shell thickness.

Science.gov (United States)

Jiang, Qian; Zeng, Wenxia; Zhang, Canying; Meng, Zhaoguo; Wu, Jiawei; Zhu, Qunzhi; Wu, Daxiong; Zhu, Haitao

2017-12-19

Photothermal conversion materials have promising applications in many fields and therefore they have attracted tremendous attention. However, the multi-functionalization of a single nanostructure to meet the requirements of multiple photothermal applications is still a challenge. The difficulty is that most nanostructures have specific absoprtion band and are not flexible to different demands. In the current work, we reported the synthesis and multi-band photothermal conversion of Ag@Ag 2 S core@shell structures with gradually varying shell thickness. We synthesized the core@shell structures through the sulfidation of Ag nanocubes by taking the advantage of their spatially different reactivity. The resulting core@shell structures show an octopod-like mopgorlogy with a Ag 2 S bulge sitting at each corner of the Ag nanocubes. The thickness of the Ag 2 S shell gradually increases from the central surface towards the corners of the structure. The synthesized core@shell structures show a broad band absorption spectrum from 300 to 1100 nm. Enhanced photothermal conversion effect is observed under the illuminations of 635, 808, and 1064 nm lasers. The results indicate that the octopod-like Ag@Ag 2 S core@shell structures have characteristics of multi-band photothermal conversion. The current work might provide a guidance for the design and synthesis of multifunctional photothermal conversion materials.

In-situ construction of Au nanoparticles confined in double-shelled TiO2/mSiO2 hollow architecture for excellent catalytic activity and enhanced thermal stability

Science.gov (United States)

Fang, Jiasheng; Zhang, Yiwei; Zhou, Yuming; Zhang, Chao; Zhao, Shuo; Zhang, Hongxing; Sheng, Xiaoli

2017-01-01

A facile strategy has been developed for the synthesis of H-TS-Au microspheres (MCs) with double-shelled hollow architecture and sub-5 nm Au nanoparticles (Au NPs). The synthetic procedure involves the successive sol-gel template-assisted method for the preparation of uniform hierarchical hollow-in-hollow H-TS MCs with TiO2/mSiO2 as yolks/shells, and the unique deposition-precipitation method mediated with Au(en)2Cl3 precursors for the in-situ construction of extremely stable Au NPs under a low-temperature hydrogen reduction. The synthesized H-TS-Au MCs were characterized by TEM, SEM, FTIR, XRD, BET and UV-vis absorption spectra. Catalytic activity of H-TS-Au was evaluated using the reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) by NaBH4. Results established that H-TS-Au MCs possessed a large-size double-shelled architecture with high structural integrity and robustness,which can effectively confine numerous tiny Au NPs and restrict them from sintering aggregation even up to further calcination at 800 °C. Owing to the advantageous structural configuration and the synergistic effect of TiO2/mSiO2 double shells, the H-TS-Au MCs were demonstrated to exhibit a remarkable catalytic activity and stability, and preserve the intact morphology after 6 repeating reduction of 4-NP.

Double Shell Tanks (DST) and Waste Feed Delivery Project Management Quality Affecting Procedures Management Plan

International Nuclear Information System (INIS)

LUND, D.P.

2000-01-01

The purpose of the Double Shell Tanks (DST) and Waste Feed Delivery (WFD) Management Assessment Plan is to define how management assessments within DST h WFD will be conducted. The plan as written currently includes only WFD Project assessment topics. Other DST and WFD group assessment topics will be added in future revisions

Shell and Double Concentric Tube Heat Exchanger Calculations and Analysis

Directory of Open Access Journals (Sweden)

Basma Abbas Abdulmajeed

2015-01-01

Full Text Available This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations. The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m3/h and 7.63 m3/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop. A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%. The percentage errors for the pressure drop in the shell and in the concentric tubes were (17.2% and (- 39% respectively. For cold water outlet temperature, the percentage error was (- 3.3%, while it was (18% considering the pressure drop in the annulus formed. The percentage error for the total power consumed was (-10.8% A theoretical comparison was made between the new design and the conventional heat exchanger from the point of view of, length, mass, pressure drop and total power consumed.

A convergent iterative solution of the quantum double-well potential

International Nuclear Information System (INIS)

Friedberg, R.; Lee, T.D.; Zhao, W.Q.; Cimenser, A.

2001-01-01

We present a new convergent iterative solution for the two lowest quantum wave functions ψ ev and ψ od of the Hamiltonian with a quartic double-well potential V in one dimension. By starting from a trial function, which is by itself the exact lowest even or odd eigenstate of a different Hamiltonian with a modified potential V+δV, we construct the Green's function for the modified potential. The true wave functions, ψ ev or ψ od , then satisfy a linear inhomogeneous integral equation, in which the inhomogeneous term is the trial function, and the kernel is the product of the Green's function times the sum of δV, the potential difference, and the corresponding energy shift. By iterating this equation we obtain successive approximations to the true wave function; furthermore, the approximate energy shift is also adjusted at each iteration so that the approximate wave function is well behaved everywhere. We are able to prove that this iterative procedure converges for both the energy and the wave function at all x. The effectiveness of this iterative process clearly depends on how good the trial function is, or equivalently, how small the potential difference δV is. Although each iteration brings a correction smaller than the previous one by a factor proportional to the parameter that characterizes the smallness of δV, it is not a power series expansion in the parameter. The exact tunneling information of the modified potential is, of course, contained in the Green's function; by adjusting the kernel of the integral equation via the energy shift at each iteration, we bring enough of this information into the calculation so that each approximate wave function is exponentially tuned. This is the underlying reason why the present method converges, while the usual power series expansion does not

Entropy Generation of Shell and Double Concentric Tubes Heat Exchanger

Directory of Open Access Journals (Sweden)

basma abbas abdulmajeed

2016-06-01

Full Text Available Entropy generation was studied for new type of heat exchanger (shell and double concentric tubes heat exchanger. Parameters of hot oil flow rate, temperature of inlet hot oil and pressure drop were investigated with the concept of entropy generation. The results showed that the value of entropy generation increased with increasing the flow rate of hot oil and when cold water flow rate was doubled from 20 to 40 l/min, these values were larger. On the other hand, entropy generation increased with increasing the hot oil inlet temperature at a certain flow rate of hot oil. Furthermore, at a certain hot oil inlet temperature, the entropy generation increased with the pressure drop at different hot oil inlet flow rates. Finally, in order to keep up with modern technology, infrared thermography camera was used in order to measure the temperatures. The entropy generation was determined with lower values when infrared thermography camera was used to measure the temperatures, compared with the values obtained by using thermocouples.

Fast fission assisted ignition of thermonuclear microexplosions

International Nuclear Information System (INIS)

Winterberg, F.

2006-01-01

It is shown that the requirements for fast ignition of thermonuclear microexplosions can be substantially relaxed if the deuterium-tritium (DT) hot spot is placed inside a shell of U-238 (Th-232). An intense laser - or particle beam-projected into the shell leads to a large temperature gradient between the hot DT and the cold U-238 (Th-232), driving thermomagnetic currents by the Nernst effect, with magnetic fields large enough to entrap within the hot spot the α-particles of the DT fusion reaction. The fast fission reactions in the U-238 (Th-232) shell implode about 1/2 of the shell onto the DT, increasing its density and reaction rate. With the magnetic field generated by the Nernst effect, there is no need to connect the target to a large current carrying transmission line, as it is required for magnetized target fusion, solving the so-called ''stand off'' problem for thermonuclear microexplosions. (orig.)

Isogeometric shell formulation based on a classical shell model

KAUST Repository

Niemi, Antti

2012-09-04

This paper constitutes the first steps in our work concerning isogeometric shell analysis. An isogeometric shell model of the Reissner-Mindlin type is introduced and a study of its accuracy in the classical pinched cylinder benchmark problem presented. In contrast to earlier works [1,2,3,4], the formulation is based on a shell model where the displacement, strain and stress fields are defined in terms of a curvilinear coordinate system arising from the NURBS description of the shell middle surface. The isogeometric shell formulation is implemented using the PetIGA and igakit software packages developed by the authors. The igakit package is a Python package used to generate NURBS representations of geometries that can be utilised by the PetIGA finite element framework. The latter utilises data structures and routines of the portable, extensible toolkit for scientific computation (PETSc), [5,6]. The current shell implementation is valid for static, linear problems only, but the software package is well suited for future extensions to geometrically and materially nonlinear regime as well as to dynamic problems. The accuracy of the approach in the pinched cylinder benchmark problem and present comparisons against the h-version of the finite element method with bilinear elements. Quadratic, cubic and quartic NURBS discretizations are compared against the isoparametric bilinear discretization introduced in [7]. The results show that the quadratic and cubic NURBS approximations exhibit notably slower convergence under uniform mesh refinement as the thickness decreases but the quartic approximation converges relatively quickly within the standard variational framework. The authors future work is concerned with building an isogeometric finite element method for modelling nonlinear structural response of thin-walled shells undergoing large rigid-body motions. The aim is to use the model in a aeroelastic framework for the simulation of flapping wings.

Adaptative mixed methods to axisymmetric shells

International Nuclear Information System (INIS)

Malta, S.M.C.; Loula, A.F.D.; Garcia, E.L.M.

1989-09-01

The mixed Petrov-Galerkin method is applied to axisymmetric shells with uniform and non uniform meshes. Numerical experiments with a cylindrical shell showed a significant improvement in convergence and accuracy with adaptive meshes. (A.C.A.S.) [pt

Innovative ICF scheme-impact fast ignition

International Nuclear Information System (INIS)

Murakami, M.; Nagatomo, H.; Sakaiya, T.; Karasik, M.; Gardner, J.; Bates, J.

2007-01-01

A totally new ignition scheme for ICF, impact fast ignition (IFI), is proposed [1], in which the compressed DT main fuel is to be ignited by impact collision of another fraction of separately imploded DT fuel, which is accelerated in the hollow conical target. Two-dimensional hydrodynamic simulation results in full geometry are presented, in which some key physical parameters for the impact shell dynamics such as 10 8 cm/s of the implosion velocity, 200- 300 g/cm 3 of the compressed density, and the converted temperature beyond 5 keV are demonstrated. As the first step toward the proof-of-principle of IFI, we have conducted preliminary experiments under the operation of GEKKO XII/HYPER laser system to achieve a hyper-velocity of the order of 108 cm/s. As a result we have observed a highest velocity, 6.5 x 10 7 cm/s, ever achieved. Furthermore, we have also done the first integrated experiments using the target and observed substantial amount of neutron yields. Reference: [1] M. Murakami and Nagatomo, Nucl. Instrum. Meth. Phys. Res. A 544(2005) 67

Qualification of a high-efficiency, gated spectrometer for x-ray Thomson scattering on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Döppner, T.; Kritcher, A. L.; Bachmann, B.; Burns, S.; Hawreliak, J.; House, A.; Landen, O. L.; LePape, S.; Ma, T.; Pak, A.; Swift, D. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Neumayer, P. [Gesellschaft für Schwerionenphysik, 64291 Darmstadt (Germany); Kraus, D. [University of California, Berkeley, California 94720 (United States); Falcone, R. W. [University of California, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94309 (United States)

2014-11-15

We have designed, built, and successfully fielded a highly efficient and gated Bragg crystal spectrometer for x-ray Thomson scattering measurements on the National Ignition Facility (NIF). It utilizes a cylindrically curved Highly Oriented Pyrolytic Graphite crystal. Its spectral range of 7.4–10 keV is optimized for scattering experiments using a Zn He-α x-ray probe at 9.0 keV or Mo K-shell line emission around 18 keV in second diffraction order. The spectrometer has been designed as a diagnostic instrument manipulator-based instrument for the NIF target chamber at the Lawrence Livermore National Laboratory, USA. Here, we report on details of the spectrometer snout, its novel debris shield configuration and an in situ spectral calibration experiment with a Brass foil target, which demonstrated a spectral resolution of E/ΔE = 220 at 9.8 keV.

Descriptions and diagrams of the primary and annulus ventilation systems of the double-shell tank farms as of January 1988

International Nuclear Information System (INIS)

Blackman, A.E.; Waters, E.D.

1994-01-01

This document is a compilation of information describing the ventilation systems of the Double-Shell Tank farms (214-AN, -AP, -AW, -AW, -AY, -AZ, and -SY). A general description of the primary tank and annulus ventilation systems is given along with specific information on the high efficiency particulate air (HEPA) filters, condensers, preheaters, exhaust fans, and piping. This information is considered to be current as of January 1988. 38 refs, 20 figs, 30 tabs

Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

Energy Technology Data Exchange (ETDEWEB)

Korakianitis, T.; Namasivayam, A.M.; Crookes, R.J. [School of Engineering and Materials Science, Queen Mary University of London (United Kingdom)

2011-02-15

Natural gas is a fossil fuel that has been used and investigated extensively for use in spark-ignition (SI) and compression-ignition (CI) engines. Compared with conventional gasoline engines, SI engines using natural gas can run at higher compression ratios, thus producing higher thermal efficiencies but also increased nitrogen oxide (NO{sub x}) emissions, while producing lower emissions of carbon dioxide (CO{sub 2}), unburned hydrocarbons (HC) and carbon monoxide (CO). These engines also produce relatively less power than gasoline-fueled engines because of the convergence of one or more of three factors: a reduction in volumetric efficiency due to natural-gas injection in the intake manifold; the lower stoichiometric fuel/air ratio of natural gas compared to gasoline; and the lower equivalence ratio at which these engines may be run in order to reduce NO{sub x} emissions. High NO{sub x} emissions, especially at high loads, reduce with exhaust gas recirculation (EGR). However, EGR rates above a maximum value result in misfire and erratic engine operation. Hydrogen gas addition increases this EGR threshold significantly. In addition, hydrogen increases the flame speed of the natural gas-hydrogen mixture. Power levels can be increased with supercharging or turbocharging and intercooling. Natural gas is used to power CI engines via the dual-fuel mode, where a high-cetane fuel is injected along with the natural gas in order to provide a source of ignition for the charge. Thermal efficiency levels compared with normal diesel-fueled CI-engine operation are generally maintained with dual-fuel operation, and smoke levels are reduced significantly. At the same time, lower NO{sub x} and CO{sub 2} emissions, as well as higher HC and CO emissions compared with normal CI-engine operation at low and intermediate loads are recorded. These trends are caused by the low charge temperature and increased ignition delay, resulting in low combustion temperatures. Another factor is

Updated tokamak systems code and applications to high-field ignition devices

International Nuclear Information System (INIS)

Reid, R.L.; Galambos, J.D.; Peng, Y-K.M.; Strickler, D.J.; Selcow, E.C.

1985-01-01

This paper describes revisions made to the Tokamak Systems Code to more accurately model high-field copper ignition devices. The major areas of revision were in the plasma physics model, the toroidal field (TF) coil model, and the poloidal field (PF) coil/MHD model. Also included in this paper are results obtained from applying the revised code to a study for a high-field copper ignition device to determine the impact of magnetic field on axis, (at the major radius), on performance, and on cost

High-speed imaging of inhomogeneous ignition in a shock tube

Science.gov (United States)

Tulgestke, A. M.; Johnson, S. E.; Davidson, D. F.; Hanson, R. K.

2018-05-01

Homogeneous and inhomogeneous ignition of real and surrogate fuels were imaged in two Stanford shock tubes, revealing the influence of small particle fragmentation. n-Heptane, iso-octane, and Jet A were studied, each mixed in an oxidizer containing 21% oxygen and ignited at low temperatures (900-1000 K), low pressures (1-2 atm), with an equivalence ratio of 0.5. Visible images (350-1050 nm) were captured through the shock tube endwall using a high-speed camera. Particles were found to arrive near the endwalls of the shock tubes approximately 5 ms after reflection of the incident shock wave. Reflected shock wave experiments using diaphragm materials of Lexan and steel were investigated. Particles collected from the shock tubes after each experiment were found to match the material of the diaphragm burst during the experiment. Following each experiment, the shock tubes were cleaned by scrubbing with cotton cloths soaked with acetone. Particles were observed to fragment after arrival near the endwall, often leading to inhomogeneous ignition of the fuel. Distinctly more particles were observed during experiments using steel diaphragms. In experiments exhibiting inhomogeneous ignition, flames were observed to grow radially until all the fuel within the cross section of the shock tube had been consumed. The influence of diluent gas (argon or helium) was also investigated. The use of He diluent gas was found to suppress the number of particles capable of causing inhomogeneous flames. The use of He thus allowed time history studies of ignition to extend past the test times that would have been limited by inhomogeneous ignition.

The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

Energy Technology Data Exchange (ETDEWEB)

Zylstra, A. B., E-mail: zylstra@mit.edu; Frenje, J. A.; Séguin, F. H.; Rosenberg, M. J.; Rinderknecht, H. G.; Gatu Johnson, M.; Li, C. K.; Manuel, M. J.-E.; Petrasso, R. D.; Sinenian, N.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Friedrich, S.; Bionta, R.; Atherton, J.; Barrios, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-11-15

The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D{sup 3}He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D{sup 3}He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2× higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (ρR) and the shell center-of-mass radius (R{sub cm}) from the downshift of the shock-produced D{sup 3}He protons. The observed ρR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time (“short-coast”), while longer-coasting implosions have lower ρR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (∼800 ps) than in the short-coast (∼400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel ρR.

The effect of shock dynamics on compressibility of ignition-scale National Ignition Facility implosions

International Nuclear Information System (INIS)

Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Rosenberg, M. J.; Rinderknecht, H. G.; Gatu Johnson, M.; Li, C. K.; Manuel, M. J.-E.; Petrasso, R. D.; Sinenian, N.; Sio, H. W.; Hicks, D. G.; Dewald, E. L.; Robey, H. F.; Rygg, J. R.; Meezan, N. B.; Friedrich, S.; Bionta, R.; Atherton, J.; Barrios, M.

2014-01-01

The effects of shock dynamics on compressibility of indirect-drive ignition-scale surrogate implosions, CH shells filled with D 3 He gas, have been studied using charged-particle spectroscopy. Spectral measurements of D 3 He protons produced at the shock-bang time probe the shock dynamics and in-flight characteristics of an implosion. The proton shock yield is found to vary by over an order of magnitude. A simple model relates the observed yield to incipient hot-spot adiabat, suggesting that implosions with rapid radiation-power increase during the main drive pulse may have a 2× higher hot-spot adiabat, potentially reducing compressibility. A self-consistent 1-D implosion model was used to infer the areal density (ρR) and the shell center-of-mass radius (R cm ) from the downshift of the shock-produced D 3 He protons. The observed ρR at shock-bang time is substantially higher for implosions, where the laser drive is on until near the compression bang time (“short-coast”), while longer-coasting implosions have lower ρR. This corresponds to a much larger temporal difference between the shock- and compression-bang time in the long-coast implosions (∼800 ps) than in the short-coast (∼400 ps); this will be verified with a future direct bang-time diagnostic. This model-inferred differential bang time contradicts radiation-hydrodynamic simulations, which predict constant 700–800 ps differential independent of coasting time; this result is potentially explained by uncertainties in modeling late-time ablation drive on the capsule. In an ignition experiment, an earlier shock-bang time resulting in an earlier onset of shell deceleration, potentially reducing compression and, thus, fuel ρR

Progress in the shock-ignition inertial confinement fusion concept

International Nuclear Information System (INIS)

Theobald, W.; Casner, A.; Nora, R.; Ribeyre, X.; Lafon, M.; Anderson, K. S.; Betti, R.; Craxton, R. S.; Delettrez, J. A.; Frenje, J. A.; Glebov, V. Yu; Gotchev, O. V.; Hohenberger, M.; Hu, S. X.; Marshall, F. J.; McCrory, R. L.; Meyerhofer, D. D.; Perkins, L. J.; Sangster, T. C.; Schurtz, G.; Seka, W.; Smalyuk, V. A.; Stoeckl, C.; Yaakobi, B.

2013-01-01

Shock-ignition experiments with peak laser intensities of ∼8 x 10 15 W/cm 2 were performed. D 2 -filled plastic shells were compressed on a low adiabat by 40 of the 60 OMEGA beams. The remaining 20 beams were delayed and tightly focused onto the imploding shell to generate a strong shock. Up to 35% backscattering of laser energy was measured at the highest intensity. Hard x-ray measurements reveal a relatively low hot-electron temperature of ∼40 keV, independent of intensity and spike onset time. (authors)

Equilibrium ignition for ICF capsules

International Nuclear Information System (INIS)

Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

1993-01-01

There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative

Implosion dynamics measurements at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Callahan, D. A.; Doeppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-12-15

Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1-1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% {+-} 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%-70%) of its initial radius, reduced the shell thickness and improved the final fuel {rho}R on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell

Implosion dynamics measurements at the National Ignition Facility

International Nuclear Information System (INIS)

Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Callahan, D. A.; Döppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P.

2012-01-01

Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1–1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% ± 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%–70%) of its initial radius, reduced the shell thickness and improved the final fuel ρR on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell

Implosion dynamics measurements at the National Ignition Facility

Science.gov (United States)

Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Olson, R. E.; Callahan, D. A.; Döppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Frenje, J. A.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P.; Izumi, N.; Kalantar, D. H.; Khan, S. F.; Kline, J. L.; Kroll, J. J.; Kyrala, G. A.; Ma, T.; MacPhee, A. G.; McNaney, J. M.; Moody, J. D.; Moran, M. J.; Nathan, B. R.; Nikroo, A.; Opachich, Y. P.; Petrasso, R. D.; Prasad, R. R.; Ralph, J. E.; Robey, H. F.; Rinderknecht, H. G.; Rygg, J. R.; Salmonson, J. D.; Schneider, M. B.; Simanovskaia, N.; Spears, B. K.; Tommasini, R.; Widmann, K.; Zylstra, A. B.; Collins, G. W.; Landen, O. L.; Kilkenny, J. D.; Hsing, W. W.; MacGowan, B. J.; Atherton, L. J.; Edwards, M. J.

2012-12-01

Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1-1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% ± 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%-70%) of its initial radius, reduced the shell thickness and improved the final fuel ρR on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell thickness

Spark igniter having precious metal ground electrode inserts

International Nuclear Information System (INIS)

Ryan, N.A.

1988-01-01

This patent describes an igniter comprising a shell of a shell metal alloy which is resistant to spark erosion and corrosion, the shell having a firing end which terminates at its lower end in an annular ring, an insulator sealed within the metal shell and having a central bore and a surface extending inwardly toward the bore from the annular ring, a center electrode sealed within the bore of the insulator and having a firing end which is in spark gap relation with the annular ring of the shell and so positioned that a spark discharge between the firing end and the annular ring occurs along the inwardly extending surface of the insulator, and a plurality of oxidation and erosion resistant inserts, each of the inserts comprising a body of a metal selected from the group consisting of iridium, osmium, ruthenium, rhodium, platinum, and tungsten or an alloy or a ductile alloy of one of the foregoing metals, each of the bodies being embedded within a matching opening which extends from the exterior of the shell through the annular ring, being bonded to the shell

Synthesis and Growth Mechanism of Multimetallic Core-Shell and Hollow-Like Nanoparticles

Science.gov (United States)

Londono-Calderon, Alejandra

A thorough control of nanoscale systems is crucial for developing and improving their activity in a variety of application fields. These range from nanocatalysis, plasmonics, nanosensors, nanomedicine, communications, and others. Controlling and understanding the growth and spatial distribution of multi metallic systems allow us to explore the correlation between the characteristics of the nanoparticle (composition, surface chemistry, crystallinity, etc.) and their properties (mechanical, optical, structural, etc.). In this dissertation bimetallic and multi-metallic nanoparticles were obtained by a seed mediated method and galvanic replacement. Combinations of the type core shell of Au Ag, Au Pd and Au Pd-Au Au multi-metallic systems were studied. A galvanic replacement method was used to obtain hollow-like Au/Pt nanoboxes and Au AgM (M = Au, Pd or Pt) yolk-shell structures with voids in the middle shell. Characterization regarding composition, morphology, optical properties and atomic structures was performed. The mechanical properties of Au Pd nanocubes were studied in situ by the use of a TEM-AFM nanomechanical holder. The nanoparticles strengthening mechanism relies on the Au core resistance to the motion of partial dislocations. The catalytic efficiency of core-shell and nanorattles structures were tested with a model reaction for the decomposition of 4-ntp to 4-amp. Yolk-shell systems exhibit an enhancement in the catalytic decomposition rate in comparison with solid and bimetallic system. Finally, the development of an Electrospray assisted Langmuir Blodgett technique was successfully employed for the deposition of nanoparticles monolayer on a substrate. High particle density and coverage of the substrate makes this a promising technique to finely tune nanoparticles self-assembly.

The Ignition Target for the National Ignition Facility

International Nuclear Information System (INIS)

Atherton, L J; Moses, E I; Carlisle, K; Kilkenny, J

2007-01-01

The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. When completed in 2009, NIF will be able to produce 1.8 MJ, 500 TW of ultraviolet light for target experiments that will create conditions of extreme temperatures (>10 8 K), pressures (10-GBar) and matter densities (> 100 g/cm 3 ). A detailed program called the National Ignition Campaign (NIC) has been developed to enable ignition experiments in 2010, with the goal of producing fusion ignition and burn of a deuterium-tritium (DT) fuel mixture in millimeter-scale target capsules. The first of the target experiments leading up to these ignition shots will begin in 2008. Targets for the National Ignition Campaign are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. An overview of the campaign for ignition will be presented, along with technologies for target fabrication, assembly and metrology and advances in growth and x-ray imaging of DT ice layers. The sum of these efforts represents a quantum leap in target precision, characterization, manufacturing rate and flexibility over current state-of-the-art

Combustion in a High-Speed Compression-Ignition Engine

Science.gov (United States)

Rothrock, A M

1933-01-01

An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur. The results show that by increasing the air temperature during injection the start of combustion can be forced to take place during injection and so prevent detonation from occurring. It is shown that the rate of fuel injection does not in itself control the rate of combustion.

Mechanistic analysis of double-shell tank gas release

Energy Technology Data Exchange (ETDEWEB)

Allemann, R.T.; Antoniak, Z.I.; Friley, J.R.; Haines, C.E.; Liljegren, L.M.; Somasundaram, S.

1991-12-01

Pacific Northwest Laboratory (PNL) is studying possible mechanisms and fluid dynamics contributing to the periodic release of gases from the double-shell waste storage tanks at Hanford. This study is being conducted for Westinghouse Hanford Company (WHC), a contractor for the US Department of Energy (DOE). This interim report discusses the work done through November 1990. Safe management of the wastes at Hanford depends on an understanding of the chemical and physical mechanisms that take place in the waste tanks. An example of the need to understand these mechanisms is tank 101-SY. The waste in this tank is generating and periodically releasing potentially flammable gases into the tank vent system according to observations of the tank. How these gases are generated and become trapped, the causes of periodic release, and the mechanism of the release are not known in detail. In order to develop a safe mitigation strategy, possible physical mechanisms for the periodic release of flammable gases need to be understood.

Enhanced photocatalytic performance and degradation pathway of Rhodamine B over hierarchical double-shelled zinc nickel oxide hollow sphere heterojunction

Science.gov (United States)

Zhang, Ying; Zhou, Jiabin; Cai, Weiquan; Zhou, Jun; Li, Zhen

2018-02-01

In this study, hierarchical double-shelled NiO/ZnO hollow spheres heterojunction were prepared by calcination of the metallic organic frameworks (MOFs) as a sacrificial template in air via a one-step solvothermal method. Additionally, the photocatalytic activity of the as-prepared samples for the degradation of Rhodamine B (RhB) under UV-vis light irradiation were also investigated. NiO/ZnO microsphere comprised a core and a shell with unique hierarchically porous structure. The photocatalytic results showed that NiO/ZnO hollow spheres exhibited excellent catalytic activity for RhB degradation, causing complete decomposition of RhB (200 mL of 10 g/L) under UV-vis light irradiation within 3 h. Furthermore, the degradation pathway was proposed on the basis of the intermediates during the photodegradation process using liquid chromatography analysis coupled with mass spectroscopy (LC-MS). The improvement in photocatalytic performance could be attributed to the p-n heterojunction in the NiO/ZnO hollow spheres with hierarchically porous structure and the strong double-shell binding interaction, which enhances adsorption of the dye molecules on the catalyst surface and facilitates the electron/hole transfer within the framework. The degradation mechanism of pollutant is ascribed to the hydroxyl radicals (rad OH), which is the main oxidative species for the photocatalytic degradation of RhB. This work provides a facile and effective approach for the fabrication of porous metal oxides heterojunction with high photocatalytic activity and thus can be potentially used in the environmental purification.

EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEM SUPPORTING WASTE TRANSFER OPERATIONS

International Nuclear Information System (INIS)

Kelly, S.E.; Haass, C.C.; Kovach, J.L.; Turner, D.A.

2010-01-01

This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through out the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEMS SUPPORTING WASTE TRANSFER OPERATIONS

International Nuclear Information System (INIS)

Haas, C.C.; Kovach, J.L.; Kelly, S.E.; Turner, D.A.

2010-01-01

This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS (TBACT) DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEM SUPPORTING WASTE TRANSFER OPERATIONS

Energy Technology Data Exchange (ETDEWEB)

KELLY SE; HAASS CC; KOVACH JL; TURNER DA

2010-06-03

This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste throught the DST storage system to the Waste Treatment and Immobilization Plant (WTP).

EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY FOR TOXICS -TBACT- DOUBLE SHELL TANK FARMS PRIMARY VENTILATION SYSTEMS SUPPORTING WASTE TRANSFER OPERATIONS

Energy Technology Data Exchange (ETDEWEB)

HAAS CC; KOVACH JL; KELLY SE; TURNER DA

2010-06-24

This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste through the DST storage system to the Waste Treatment and Immobilizaiton Plant (WTP).

Engineering Task Plan for the Ultrasonic Inspection of Hanford Double Shell Tanks (DST) FY2000

International Nuclear Information System (INIS)

JENSEN, C.E.

2000-01-01

This document facilitates the ultrasonic examination of Hanford double-shell tanks. Included are a plan for engineering activities (individual responsibilities), plan for performance demonstration testing, and a plan for field activities (tank inspection). Also included are a Statement of Work for contractor performance of the work and a protocol to be followed should tank flaws that exceed the acceptance criteria be discovered

FABRICATION AND PROPERTIES OVERCOATED RESORCINOL-FORMALDEHYDE SHELLS FOR OMEGA EXPERIMENTS

International Nuclear Information System (INIS)

NIKROO, A; CZECHOWICZ, D; PAGUIO, R; GREENWOOD, A.L; TAKAGI, M.

2003-09-01

OAK-B135 New high gain designs for direct drive ignition on NIF require foam shells. Scaled down versions of these designs are needed for near term experiments on the OMEGA laser facility at the Laboratory Laser Energetics (LLE). These shells need to be about 1 mm in diameter and 50-100 (micro)m wall thickness and densities of 100-250 mg/cc. In addition, a full density permeation seal needs to be deposited for retention of the fill gas at room temperature or the ice at cryogenic temperatures. They have fabricated such shells using Resorcinol-formaldehyde (R/F) as the selected foam material due to its transparency in the optical region. Extensive characterization of the wall uniformity of these shells has been performed. The foam shells have ∼ 5%-6% non-concentricities on the average. A full density permeation seal has been deposited on the R/F shells using two different techniques. In the first technique R/F shells are coated directly with plasma polymer to thicknesses of 3-4 (micro)m. In the second technique, R/F shells are coated with polyvinylphenol, using a chemical interfacial polymerization technique. Data on surface finish and gas retention for R/F shells coated by both methods are provided

Project management plan double-shell tank system specification development

International Nuclear Information System (INIS)

Conrads, T.J.

1998-01-01

The Project Hanford Management Contract (PHMC) members have been tasked by the US Department of Energy (DOE) to support removal of wastes from the Hanford Site 200 Area tanks in two phases. The schedule for these phases allows focusing on requirements for the first phase of providing feed to the privatized vitrification plants. The Tank Waste Retrieval Division near-term goal is to focus on the activities to support Phase 1. These include developing an integrated (technical, schedule, and cost) baseline and, with regard to private contractors, establishing interface agreements, constructing infrastructure systems, retrieving and delivering waste feed, and accepting immobilized waste products for interim onsite storage. This document describes the process for developing an approach to designing a system for retrieving waste from double-shell tanks. It includes a schedule and cost account for the work breakdown structure task

Double-shell tank waste system assessment status and schedule

International Nuclear Information System (INIS)

Walter, E.J.

1995-01-01

The integrated program for completing the integrity assessments of the dangerous waste tank systems managed by the Tank Waste Remediation System (TWRS) Division of Westinghouse Hanford Company is presented in the Tank Waste Remediation System Tank System Integrity Assessments Program Plan, WHC-SD-AP017, Rev. 1. The program plan identified the assessment requirements and the general scope to which these requirements applied. Some of these assessment requirements have been met and others are either in process of completion or scheduled to be worked. To define the boundary of the double-shell tank (DST) system and the boundaries of the DST system components (or system parts) for the purpose of performing integrity assessment activities; To identify the planned activities to meet the assessment requirements for each component; Provide the status of the assessment activities; and Project a five year assessment activity schedule

Vibrations of thin piezoelectric shallow shells: Two-dimensional ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

In this paper we consider the eigenvalue problem for piezoelectric shallow shells and we show that, as the thickness of the shell goes to zero, the eigensolutions of the three-dimensional piezoelectric shells converge to the eigensolutions of a two- dimensional eigenvalue problem. Keywords. Vibrations; piezoelectricity ...

Wire number doubling in plasma-shell regime increases z-accelerator x-ray power

International Nuclear Information System (INIS)

Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A.

1997-11-01

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40±20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the 'plasma shell' regime, where the plasmas generated by the individual wires merge prior to the inward implosion of the entire array

Wire number doubling in plasma-shell regime increases Z-accelerator X-ray power

International Nuclear Information System (INIS)

Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A.

1997-01-01

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40 ± 20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the plasma shell regime, where the plasma generated by the individual wires merge prior to the inward implosion of the entire array

Wire number doubling in plasma-shell regime increases Z-accelerator X-ray power

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A. [and others

1997-12-01

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40 {+-} 20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the plasma shell regime, where the plasma generated by the individual wires merge prior to the inward implosion of the entire array.

Double-shell tank integrity assessments ultrasonic test equipment performance test

Energy Technology Data Exchange (ETDEWEB)

Pfluger, D.C.

1996-09-26

A double-shell tank (DST) inspection (DSTI) system was performance tested over three months until August 1995 at Pittsburgh, Pennsylvania, completing a contract initiated in February 1993 to design, fabricate, and test an ultrasonic inspection system intended to provide ultrasonic test (UT) and visual data to determine the integrity of 28 DSTs at Hanford. The DSTs are approximately one-million-gallon underground radioactive-waste storage tanks. The test was performed in accordance with a procedure (Jensen 1995) that included requirements described in the contract specification (Pfluger 1995). This report documents the results of tests conducted to evaluate the performance of the DSTI system against the requirements of the contract specification. The test of the DSTI system also reflects the performance of qualified personnel and operating procedures.

Corona ignition system for highly efficient gasoline engines; Corona-Zuendsystem fuer hocheffiziente Ottomotoren

Energy Technology Data Exchange (ETDEWEB)

Burrows, John [Federal-Mogul Limited, Manchester (United Kingdom); Lykowski, Jim; Mixell, Kristapher [Federal-Mogul, Plymouth, MI (United States)

2013-06-01

Many future gasoline engines will require higher air/fuel ratios and higher mean effective pressures to further improve fuel efficiency. Federal-Mogul has taken up this challenge and has developed the Advanced Corona Ignition System (ACIS) as a new solution to reliably ignite a mix with high AFR/EGR and high MEP. During engine tests ACIS enabled a direct fuel economy improvement of up to 10 %. (orig.)

High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

International Nuclear Information System (INIS)

Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

2015-01-01

A recent low gas-fill density (0.6 mg/cc 4 He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4 He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth

High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

Science.gov (United States)

Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

2015-04-01

A recent low gas-fill density (0.6 mg/cc 4He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

Energy Technology Data Exchange (ETDEWEB)

Amendt, Peter; Ho, Darwin D.; Jones, Ogden S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2015-04-15

A recent low gas-fill density (0.6 mg/cc {sup 4}He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc {sup 4}He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

Spherical strong-shock generation for shock-ignition inertial fusion

Energy Technology Data Exchange (ETDEWEB)

Theobald, W.; Seka, W.; Lafon, M.; Anderson, K. S.; Hohenberger, M.; Marshall, F. J.; Michel, D. T.; Solodov, A. A.; Stoeckl, C.; Edgell, D. H.; Yaakobi, B.; Shvydky, A. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Nora, R.; Betti, R. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Department of Mechanical Engineering and Department of Physics, University of Rochester, Rochester, New York 14623 (United States); Casner, A.; Reverdin, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Ribeyre, X.; Vallet, A. [Université de Bordeaux-CNRS-CEA, CELIA (Centre Lasers Intenses et Applications) UMR 5107 F-33400 Talence (France); Peebles, J.; Beg, F. N. [University of California, San Diego, La Jolla, California 92093 (United States); and others

2015-05-15

Recent experiments on the Laboratory for Laser Energetics' OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct laser illumination. The shocks are launched at pressures of several hundred Mbars and reach Gbar upon convergence. The results are relevant to the validation of the shock-ignition scheme and to the development of an OMEGA experimental platform to study material properties at Gbar pressures. The experiments investigate the strength of the ablation pressure and the hot-electron production at incident laser intensities of ∼2 to 6 × 10{sup 15 }W/cm{sup 2} and demonstrate ablation pressures exceeding 300 Mbar, which is crucial to developing a shock-ignition target design for the National Ignition Facility. The timing of the x-ray flash from shock convergence in the center of the solid plastic target is used to infer the ablation and shock pressures. Laser–plasma instabilities produce hot-electrons with a moderate temperature (<100 keV). The instantaneous conversion efficiencies of laser power into hot-electron power reached up to ∼15% in the intensity spike. The large amount of hot electrons is correlated with an earlier x-ray flash and a strong increase in its magnitude. This suggests that hot electrons contribute to the augmentation of the shock strength.

Influence of Shell Thickness on the Colloidal Stability of Magnetic Core-Shell Particle Suspensions.

Science.gov (United States)

Neville, Frances; Moreno-Atanasio, Roberto

2018-01-01

We present a Discrete Element study of the behavior of magnetic core-shell particles in which the properties of the core and the shell are explicitly defined. Particle cores were considered to be made of pure iron and thus possessed ferromagnetic properties, while particle shells were considered to be made of silica. Core sizes ranged between 0.5 and 4.0 μm with the actual particle size of the core-shell particles in the range between 0.6 and 21 μm. The magnetic cores were considered to have a magnetization of one tenth of the saturation magnetization of iron. This study aimed to understand how the thickness of the shell hinders the formation of particle chains. Chain formation was studied with different shell thicknesses and particle sizes in the presence and absence of an electrical double layer force in order to investigate the effect of surface charge density on the magnetic core-shell particle interactions. For core sizes of 0.5 and 4.0 μm the relative shell thicknesses needed to hinder the aggregation process were approximately 0.4 and 0.6 respectively, indicating that larger core sizes are detrimental to be used in applications in which no flocculation is needed. In addition, the presence of an electrical double layer, for values of surface charge density of less than 20 mC/m 2 , could stop the contact between particles without hindering their vertical alignment. Only when the shell thickness was considerably larger, was the electrical double layer able to contribute to the full disruption of the magnetic flocculation process.

Transport simulations of ohmic ignition experiment: IGNITEX

International Nuclear Information System (INIS)

Uckan, N.A.; Howe, H.C.

1987-01-01

The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large (≤2), and anomalous radiation and alpha losses and/or other enhanced transport losses (/eta//sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters (aB 0 2 /q* /approximately/ IB 0 , etc.) are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

Transport simulations of ohmic ignition experiment: IGNITEX

International Nuclear Information System (INIS)

Uckan, N.A.; Howe, H.C.

1987-12-01

The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large, and anomalous radiation and alpha losses and/or other enhanced transport losses (eta/sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

Effects of cluster-shell competition and BCS-like pairing in 12C

Science.gov (United States)

Matsuno, H.; Itagaki, N.

2017-12-01

The antisymmetrized quasi-cluster model (AQCM) was proposed to describe α-cluster and jj-coupling shell models on the same footing. In this model, the cluster-shell transition is characterized by two parameters, R representing the distance between α clusters and Λ describing the breaking of α clusters, and the contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the α-cluster model wave function. Not only the closure configurations of the major shells but also the subclosure configurations of the jj-coupling shell model can be described starting with the α-cluster model wave functions; however, the particle-hole excitations of single particles have not been fully established yet. In this study we show that the framework of AQCM can be extended even to the states with the character of single-particle excitations. For ^{12}C, two-particle-two-hole (2p2h) excitations from the subclosure configuration of 0p_{3/2} corresponding to a BCS-like pairing are described, and these shell model states are coupled with the three α-cluster model wave functions. The correlation energy from the optimal configuration can be estimated not only in the cluster part but also in the shell model part. We try to pave the way to establish a generalized description of the nuclear structure.

A new proof for the convergent iterative solution of the degenerate quantum double-well potential and its generalization

International Nuclear Information System (INIS)

Friedberg, R.; Lee, T.D.

2003-01-01

We present a new and simpler proof for the convergent iterative solution of the one-dimensional degenerate double-well potential. This new proof depends on a general theorem, called the hierarchy theorem, that shows the successive stages in the iteration to form a monotonically increasing sequence of approximations to the energy and to the wavefunction at any point x. This important property makes possible a much simpler proof of convergence than the one given before in the literature. The hierarchy theorem proven in this paper is applicable to a much wider class of potentials which includes the quartic potential

Introduction to the physics of ICF capsules

International Nuclear Information System (INIS)

Lindl, J.D.

1989-01-01

Inertial Confinement Fusion is an approach to fusion which relies on the inertia of the fuel mass to provide confinement. To achieve conditions under which this confinement is sufficient for efficient thermonuclear burn, high gain ICF targets designed to be imploded directly by laser light. These capsules are generally a spherical shell which is filled with low density DT gas. The shell is composed of an outer region which forms the ablator and an inner region of frozen or liquid DT which forms the main fuel. Energy from the driver is delivered to the ablator which heats up and expands. As the ablator expands and blows outward, the rest of the shell is forced inward to conserve momentum. In this implosion process, several features are important. We define the in-flight-aspect-ratio (IFAR) as the ratio of the shell radius R as it implodes to its thickness ΔR. Hydrodynamic instabilities during the implosion impose limits on this ratio which results in a minimum pressure requirement of about 100 Mbar. The convergence ratio is defined as the ratio of the initial outer radius of the ablator to the final compressed radius of the hot spot. This hot spot is the central region of the compressed fuel which is required to ignite the main fuel in high gain designs. Typical convergence ratios are 30--40. To maintain a nearly spherical shape during the implosion, when convergence ratios are this large, the flux delivered to the capsule must be uniform to a few percent. The remainder of this paper discusses the conditions necessary to achieve thermonuclear ignition in these ICF capsules

Multi-shelled ZnCo2O4 yolk-shell spheres for high-performance acetone gas sensor

Science.gov (United States)

Xiong, Ya; Zhu, Zongye; Ding, Degong; Lu, Wenbo; Xue, Qingzhong

2018-06-01

In the present study, multi-shelled ZnCo2O4 yolk-shell spheres have been successfully prepared by using carbonaceous microspheres as templates. It is found that the multi-shelled ZnCo2O4 yolk-shell spheres based sensor shows optimal sensing performances (response value of 38.2, response/recovery time of 19 s/71 s) toward 500 ppm acetone at 200 °C. In addition, this sensor exhibits a low detection limit of 0.5 ppm acetone (response value of 1.36) and a good selectivity toward hydrogen, methane, ethanol, ammonia and carbon dioxide. Furthermore, it is demonstrated that acetone gas response of multi-shelled ZnCo2O4 yolk-shell spheres is significantly better than that of ZnCo2O4 nanotubes and ZnCo2O4 nanosheets. High acetone response of the multi-shelled ZnCo2O4 yolk-shell spheres is attributed to the enhanced gas accessibility of the multi-shell morphology caused by the small crystalline size and high specific surface area while the short response/recovery time is mainly related to the rapid gas diffusion determined by the highly porous structure. Our work puts forward an exciting opportunity in designing various yolk-shelled structures for multipurpose applications.

Wire number doubling in plasma-shell regime increases z-accelerator x-ray power

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A. [and others

1997-11-01

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40{+-}20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the {open_quotes}plasma shell{close_quotes} regime, where the plasmas generated by the individual wires merge prior to the inward implosion of the entire array.

Symplectic no-core shell-model approach to intermediate-mass nuclei

Science.gov (United States)

Tobin, G. K.; Ferriss, M. C.; Launey, K. D.; Dytrych, T.; Draayer, J. P.; Dreyfuss, A. C.; Bahri, C.

2014-03-01

We present a microscopic description of nuclei in the intermediate-mass region, including the proximity to the proton drip line, based on a no-core shell model with a schematic many-nucleon long-range interaction with no parameter adjustments. The outcome confirms the essential role played by the symplectic symmetry to inform the interaction and the winnowing of shell-model spaces. We show that it is imperative that model spaces be expanded well beyond the current limits up through 15 major shells to accommodate particle excitations, which appear critical to highly deformed spatial structures and the convergence of associated observables.

A Chemical-Adsorption Strategy to Enhance the Reaction Kinetics of Lithium-Rich Layered Cathodes via Double-Shell Surface Modification.

Science.gov (United States)

Guo, Lichao; Li, Jiajun; Cao, Tingting; Wang, Huayu; Zhao, Naiqin; He, Fang; Shi, Chunsheng; He, Chunnian; Liu, Enzuo

2016-09-21

Sluggish surface reaction kinetics hinders the power density of Li-ion battery. Thus, various surface modification techniques have been applied to enhance the electronic/ionic transfer kinetics. However, it is challenging to obtain a continuous and uniform surface modification layer on the prime particles with structure integration at the interface. Instead of classic physical-adsorption/deposition techniques, we propose a novel chemical-adsorption strategy to synthesize double-shell modified lithium-rich layered cathodes with enhanced mass transfer kinetics. On the basis of experimental measurement and first-principles calculation, MoO2S2 ions are proved to joint the layered phase via chemical bonding. Specifically, the Mo-O or Mo-S bonds can flexibly rotate to bond with the cations in the layered phase, leading to the good compatibility between the thiomolybdate adsorption layer and layered cathode. Followed by annealing treatment, the lithium-excess-spinel inner shell forms under the thiomolybdate adsorption layer and functions as favorable pathways for lithium and electron. Meanwhile, the nanothick MoO3-x(SO4)x outer shell protects the transition metal from dissolution and restrains electrolyte decomposition. The double-shell modified sample delivers an enhanced discharge capacity almost twice as much as that of the unmodified one at 1 A g(-1) after 100 cycles, demonstrating the superiority of the surface modification based on chemical adsorption.

A Brief Study on the Ignition of the Non-Thermal Atmospheric Pressure Plasma Jet from a Double Dielectric Barrier Configured Plasma Pencil

International Nuclear Information System (INIS)

Begum, Asma; Laroussi, Mounir; Pervez, M. R.

2013-01-01

To understand the self sustained propagation of the plasma jet/bullet in air under atmospheric pressure, the ignition of the plasma jet/bullet, the plasma jet/bullet ignition point in the plasma pencil, the formation time and the formation criteria from a dielectric barrier configured plasma pencil were investigated in this study. The results were confirmed by comparing these results with the plasma jet ignition process in the plasma pencil without a dielectric barrier. Electrical, optical, and imaging techniques were used to study the formation of the plasma jet from the ignition of discharge in a double dielectric barrier configured plasma pencil. The investigation results show that the plasma jet forms at the outlet of the plasma pencil as a donut shaped discharge front because of the electric field line along the outlet's surface. It is shown that the required time for the formation of the plasma jet changes with the input voltage of the discharge. The input power calculation for the gap discharge and for the whole system shows that 56% of the average input power is used by the first gap discharge. The estimated electron density inside the gap discharge is in the order of 10 11 cm −3 . If helium is used as a feeding gas, a minimum 1.48×10 −8 C charge is required per pulse in the gap discharge to generate a plasma jet

Tank characterization report for double-shell Tank 241-AW-105

International Nuclear Information System (INIS)

DiCenso, A.T.; Amato, L.C.; Franklin, J.D.; Lambie, R.W.; Stephens, R.H.; Simpson, B.C.

1994-01-01

In May 1990, double-shell Tank 241-AW-105 was sampled to determine proper handling of the waste, to address corrosivity and compatibility issues, and to comply with requirements of the Washington Administrative Code. This Tank Characterization Report presents an overview of that tank sampling and analysis effort, and contains observations regarding waste characteristics. It also addresses expected concentration and bulk inventory data for the waste contents based on this latest sampling data and background tank information. This report summarizes the available information regarding the waste in Tank 241-AW-105, and using the historical information to place the analytical data in context, arranges this information in a useful format for making management and technical decisions concerning this waste tank. In addition, conclusions and recommendations are given based on safety issues and further characterization needs

Double-shell tank ultrasonic inspection plan. Revision 1

International Nuclear Information System (INIS)

Pfluger, D.C.

1994-01-01

The waste tank systems managed by the Tank Waste Remediation System Division of Westinghouse Hanford Company includes 28 large underground double-shell tanks (DST) used for storing hazardous radioactive waste. The ultrasonic (UT) inspection of these tanks is part of their required integrity assessment (WAC 1993) as described in the tank systems integrity assessment program plan (IAPP) (Pfluger 1994a) submitted to the Ecology Department of the State of Washington. Because these tanks hold radioactive waste and are located underground examinations and inspections must be done remotely from the tank annuli with specially designed equipment. This document describes the UT inspection system (DSTI system), the qualification of the equipment and procedures, field inspection readiness, DST inspections, and post-inspection activities. Although some of the equipment required development, the UT inspection technology itself is the commercially proven and available projection image scanning technique (P-scan). The final design verification of the DSTI system will be a performance test in the Hanford DST annulus mockup that includes the demonstration of detecting and sizing corrosion-induced flaws

Zero-point energy of N perfectly conducting concentric cylindrical shells

International Nuclear Information System (INIS)

Tatur, K.; Woods, L.M.

2008-01-01

The zero-point (Casimir) energy of N perfectly conducting, infinitely long, concentric cylindrical shells is calculated utilizing the mode summation technique. The obtained convergent expression is studied as a function of size, curvature and number of shells. Limiting cases, such as infinitely close shells or infinite radius shells are also investigated

Some double sequence spaces of interval numbers defined by Orlicz function

Directory of Open Access Journals (Sweden)

Ayhan Esi

2014-10-01

Full Text Available In this paper we introduce some interval valued double sequence spaces defined by Orlicz function and study different properties of these spaces like inclusion relations, solidity, etc. We establish some inclusion relations among them. Also we introduce the concept of double statistical convergence for interval number sequences and give an inclusion relation between interval valued double sequence spaces.

Ignition of deuterium based fuel cycles in a high beta system

International Nuclear Information System (INIS)

Hirano, K.

1987-01-01

A steady state self-consistent plasma modeling applied to a system having close to unity, such as FRC or like, is found to be quite effective in solving the problems independently of any anomalous process and proves the existence of ignited state of deuterium based fuel cycles. The temperature ranges that the plasma falls into ignited state are obtained as a function of relative feeding rates of tritium and 3 He to deuterium's. We find pure DD cycle will not ignite so that 3 He or/and tritium must be added as catalyzer to achieve ignition. Standing on the points to construct a cleaner system yielding smaller amount of 14 MeV neutrons and to burn the fuel in steady state for long periods of time, we have confirmed superiority of the complex composed of the master reactor of 3 He-Cat.D cycle (catalyzed DD cycle reinjecting only fusion produced 3 He) and the satellite reactor of 3 He enriched D 3 He cycle. In case storage of tritium for 3 He by β - decay is turned out not to be allowed environmentally, we may utilize conventional catalyzed DD cycle although 14 MeV neutron yields will be increased by 35 % over the complex. It is demonstrated that advanced fuel cycle reactors can be very simple in constructions and compact in size such that the field strength and the plasma volume of the order of JT-60's may be enough for 1000 MW power plant. (author)

Gamma Reaction History ablator areal density constraints upon correlated diagnostic modeling of National Ignition Facility implosion experiments

Energy Technology Data Exchange (ETDEWEB)

Cerjan, C., E-mail: cerjan1@llnl.gov; Sayre, D. B.; Landen, O. L.; Church, J. A.; Stoeffl, W. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Grafil, E. M. [Colorado School of Mines, Golden, Colorado 80401 (United States); Herrmann, H. W.; Hoffman, N. M.; Kim, Y. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2015-03-15

The inelastic neutron scattering induced γ-ray signal from {sup 12}C in an Inertial Confinement Fusion capsule is demonstrated to be an effective and general diagnostic for shell ablator areal density. Experimental acquisition of the time-integrated signal at 4.4 MeV using threshold detection from four gas Čerenkov cells provides a direct measurement of the {sup 12}C areal density near stagnation. Application of a three-dimensional isobaric static model of data acquired in a recent high neutron yield National Ignition Facility experimental campaign reveals two general trends: smaller remaining ablator mass at stagnation and higher shell density with increasing laser drive.

Ignition and Inertial Confinement Fusion at The National Ignition Facility

International Nuclear Information System (INIS)

Moses, E.

2009-01-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm 3 -sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

Energy Technology Data Exchange (ETDEWEB)

Addai, Emmanuel Kwasi, E-mail: emmanueladdai41@yahoo.com; Gabel, Dieter; Krause, Ulrich

2016-04-15

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

International Nuclear Information System (INIS)

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-01-01

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

The Application of High Energy Ignition and Boosting/Mixing Technology to Increase Fuel Economy in Spark Ignition Gasoline Engines by Increasing EGR Dilution Capability

Energy Technology Data Exchange (ETDEWEB)

Keating, Edward [General Motors LLC, Pontiac, MI (United States); Gough, Charles [General Motors LLC, Pontiac, MI (United States)

2015-07-07

This report summarizes activities conducted in support of the project “The Application of High Energy Ignition and Boosting/Mixing Technology to Increase Fuel Economy in Spark Ignition Gasoline Engines by Increasing EGR Dilution Capability” under COOPERATIVE AGREEMENT NUMBER DE-EE0005654, as outlined in the STATEMENT OF PROJECT OBJECTIVES (SOPO) dated May 2012.

Polar-direct-drive experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Hohenberger, M.; Radha, P. B.; Myatt, J. F.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Fiksel, G.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States); and others

2015-05-15

To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D{sub 2} gas were imploded with total drive energies ranging from ∼500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 × 10{sup 14} to 1.2 × 10{sup 15 }W/cm{sup 2}. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

Double K-vacancy production by x-ray photoionization

International Nuclear Information System (INIS)

Southworth, S. H.; Dunford, R. W.; Kanter, E. P.; Krassig, B.; Young, L.; Armen, G. B.; Levin, J. C.; Chen, M. H.; Ederer, D. L.

2002-01-01

We have studied double K-shell photoionization of Ne and Mo (Z = 10 and 42) at the Advanced Photon Source. Double K-vacancy production in Ne was observed by recording the KK-KLL Auger hypersatellite spectrum. Comparison is made with calculations using the multiconfiguration Dirac-Fock method. For Mo, double K-vacancy production was observed by recording the Kα, β fluorescence hypersatellite and satellite x rays in coincidence. From the intensities of the Auger or x-ray hypersatellites relative to diagram lines, the probabilities for double K-vacancy production relative to single K-vacancies were determined. These results, along with reported measurements on other atoms, are compared with Z-scaling calculations of the high-energy limits of the double-to-single K-shell photoionization ratio

Auto-ignitions of a methane/air mixture at high and intermediate temperatures

Science.gov (United States)

Leschevich, V. V.; Martynenko, V. V.; Penyazkov, O. G.; Sevrouk, K. L.; Shabunya, S. I.

2016-09-01

A rapid compression machine (RCM) and a shock tube (ST) have been employed to study ignition delay times of homogeneous methane/air mixtures at intermediate-to-high temperatures. Both facilities allow measurements to be made at temperatures of 900-2000 K, at pressures of 0.38-2.23 MPa, and at equivalence ratios of 0.5, 1.0, and 2.0. In ST experiments, nitrogen served as a diluent gas, whereas in RCM runs the diluent gas composition ranged from pure nitrogen to pure argon. Recording pressure, UV, and visible emissions identified the evolution of chemical reactions. Correlations of ignition delay time were generated from the data for each facility. At temperatures below 1300 K, a significant reduction of average activation energy from 53 to 15.3 kcal/mol was obtained. Moreover, the RCM data showed significant scatter that dramatically increased with decreasing temperature. An explanation for the abnormal scatter in the data was proposed based on the high-speed visualization of auto-ignition phenomena and experiments performed with oxygen-free and fuel-free mixtures. It is proposed that the main reason for such a significant reduction of average activation energy is attributable to the premature ignition of ultrafine particles in the reactive mixture.

Reactive turbulent flow CFD study in supercritical water oxidation process: application to a stirred double shell reactor

International Nuclear Information System (INIS)

Moussiere, S.

2006-12-01

Supercritical water oxidation is an innovative process to treat organic liquid waste which uses supercritical water properties to mix efficiency the oxidant and the organic compounds. The reactor is a stirred double shell reactor. In the step of adaptation to nuclear constraints, the computational fluid dynamic modeling is a good tool to know required temperature field in the reactor for safety analysis. Firstly, the CFD modeling of tubular reactor confirms the hypothesis of an incompressible fluid and the use of k-w turbulence model to represent the hydrodynamic. Moreover, the EDC model is as efficiency as the kinetic to compute the reaction rate in this reactor. Secondly, the study of turbulent flow in the double shell reactor confirms the use of 2D axisymmetric geometry instead of 3D geometry to compute heat transfer. Moreover, this study reports that water-air mixing is not in single phase. The reactive turbulent flow is well represented by EDC model after adaptation of initial conditions. The reaction rate in supercritical water oxidation reactor is mainly controlled by the mixing. (author)

The Designated Convergence Rate Problems of Consensus or Flocking of Double-Integrator Agents With General Nonequal Velocity and Position Couplings: Further Results and Patterns of Convergence Rate Contours.

Science.gov (United States)

Li, Wei

2017-05-01

This paper considers the designated convergence rate (DCR) (or the designated convergence margin) problems of consensus or flocking of coupled double-integrator agents. The DCR problems are more valuable for systems design than just convergence or stability conditions. The system setting in this paper is general, i.e., the velocity coupling and position coupling (VCPC) between agents, respectively, are set to be general and nonequal (up to rescaling), together with distinct damping and stiffness gains for the VCPC, respectively. This paper has two primary contributions on consensus: 1) further necessary and sufficient conditions are established to guarantee the DCR problems of the system, which have enriched the previous results and 2) the patterns of the convergence rate contours for the DCR are characterized, in terms of the damping and stiffness gains, which are closely related to the characteristics of the spectra of the two Laplacian matrices of the VCPC. Additionally, this paper has a contribution on matrix theory, i.e., the sufficient conditions for the simultaneous upper-triangularization of two independent Laplacian matrices, particularly from an easily verifiable topological perspective on the corresponding digraphs of these Laplacian matrices.

Semiclassical shell structure and nuclear double-humped fission barriers

Directory of Open Access Journals (Sweden)

A. G. Magner

2010-09-01

Full Text Available We derived the semiclassical trace formulas for the level density as sums over periodic-orbit families and isolated orbits within the improved stationary phase method. Averaged level-density shell corrections and shell-structure energies are continuous through all symmetry-breaking (bifurcation points with the correct asymptotics of the standard stationary phase approach accounting for continuous symmetries. We found enhancement of the nuclear shell structure near bifurcations in the superdeformed region. Our semiclassical results for the averaged level densities with the gross-shell and more thin-shell structures and the energy shell corrections for critical deformations are in good agreement with the quantum calculations for several single-particle Hamiltonians, in particular for the potentials with a sharp spheroidal shape. Enhancement of the shell structure owing to bifurcations of the shortest 3-dimensional orbits from equatorial orbits is responsible for the second well of fission barrier in a superdeformation region.

Gas retention and release behavior in Hanford single-shell waste tanks

International Nuclear Information System (INIS)

Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

1996-12-01

This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large (∼100 m 3 ) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given

Do convergent developmental mechanisms underlie convergent phenotypes?

Science.gov (United States)

Wray, Gregory A.

2002-01-01

Convergence is a pervasive evolutionary process, affecting many aspects of phenotype and even genotype. Relatively little is known about convergence in developmental processes, however, nor about the degree to which convergence in development underlies convergence in anatomy. A switch in the ecology of sea urchins from feeding to nonfeeding larvae illustrates how convergence in development can be associated with convergence in anatomy. Comparisons to more distantly related taxa, however, suggest that this association may be limited to relatively close phylogenetic comparisons. Similarities in gene expression during development provide another window into the association between convergence in developmental processes and convergence in anatomy. Several well-studied transcription factors exhibit likely cases of convergent gene expression in distantly related animal phyla. Convergence in regulatory gene expression domains is probably more common than generally acknowledged, and can arise for several different reasons. Copyright 2002 S. Karger AG, Basel.

GLOBAL GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF BLACK HOLE ACCRETION FLOWS: A CONVERGENCE STUDY

International Nuclear Information System (INIS)

Shiokawa, Hotaka; Dolence, Joshua C.; Gammie, Charles F.; Noble, Scott C.

2012-01-01

Global, general relativistic magnetohydrodynamic (GRMHD) simulations of non-radiative, magnetized disks are widely used to model accreting black holes. We have performed a convergence study of GRMHD models computed with HARM3D. The models span a factor of four in linear resolution, from 96 × 96 × 64 to 384 × 384 × 256. We consider three diagnostics of convergence: (1) dimensionless shell-averaged quantities such as plasma β; (2) the azimuthal correlation length of fluid variables; and (3) synthetic spectra of the source including synchrotron emission, absorption, and Compton scattering. Shell-averaged temperature is, except for the lowest resolution run, nearly independent of resolution; shell-averaged plasma β decreases steadily with resolution but shows signs of convergence. The azimuthal correlation lengths of density, internal energy, and temperature decrease steadily with resolution but show signs of convergence. In contrast, the azimuthal correlation length of magnetic field decreases nearly linearly with grid size. We argue by analogy with local models, however, that convergence should be achieved with another factor of two in resolution. Synthetic spectra are, except for the lowest resolution run, nearly independent of resolution. The convergence behavior is consistent with that of higher physical resolution local model ( s hearing box ) calculations and with the recent non-relativistic global convergence studies of Hawley et al.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

Energy Technology Data Exchange (ETDEWEB)

Kim, Chul Jin; Choi, Hyo Hyun [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Sohn, Chae Hoon, E-mail: chsohn@sejong.ac.kr [Department of Mechanical Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

International Nuclear Information System (INIS)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-01

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

Self-focusing and its related interactions at very high laser intensities for fast ignition at Osaka University

International Nuclear Information System (INIS)

Tanaka, K.A.; Kodama, R.; Izumi, N.; Takahashi, K.; Heya, M.; Fujita, H.; Kato, Y.; Kitagawa, Y.; Mima, K.; Miyanaga, N.; Norimatsu, T.; Sentoku, Y.; Sunahara, A.; Takabe, H.; Yamanaka, T.; Koase, T.; Iwatani, T.; Ohtani, F.; Miyakoshi, T.; Habara, H.; Tanpo, M.; Tohyama, S.; Weber, F.A.; Barbee, T.W.; Dasilva, L.B.; Dasilva, L.B.

2000-01-01

At the Institute of Laser Engineering, various type of experiments related to fast ignition were performed with the 12-beam laser system GEKKO XII and the newly added 100 TW beams line. Using both X-ray and UV laser probes, drilling via ponderomotive laser light self-focusing was studied to show drilling well into the overdense plasma over a distance of 100 μm at a self-focused laser intensity of 10 18 W/cm 2 . This type of self-focusing accelerated electrons up to 0.1 to 1 MeV and was also applied to an imploding shell. (authors)

Modelling auto ignition of hydrogen in a jet ignition pre-chamber

Energy Technology Data Exchange (ETDEWEB)

Boretti, Alberto A. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

2010-04-15

Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. (author)

Transition from equilibrium ignition to non-equilibrium burn for ICF capsules surrounded by a high-Z pusher

International Nuclear Information System (INIS)

Li, Ji W.; Chang, Lei; Li, Yun S.; Li, Jing H.

2011-01-01

For the ICF capsule surrounded by a high-Z pusher which traps the radiation and confines the hot fuel, the fuel will first be ignited in thermal equilibrium with radiation at a much lower temperature than hot-spot ignition, which is also the low temperature ignition. Because of the lower areal density for ICF capsules, the equilibrium ignition must be developed into a non-equilibrium burn to shorten the reaction time and lower the drive energy. In this paper, the transition from the equilibrium ignition to non-equilibrium burn is discussed and the energy deposited by α particles required for the equilibrium ignition and non-equilibrium burn to occur is estimated.

Effects of mode coupling between low-mode radiation flux asymmetry and intermediate-mode ablator roughness on ignition capsule implosions

Directory of Open Access Journals (Sweden)

Jianfa Gu

2017-01-01

Full Text Available The low-mode shell asymmetry and high-mode hot spot mixing appear to be the main reasons for the performance degradation of the National Ignition Facility (NIF implosion experiments. The effects of the mode coupling between low-mode P2 radiation flux asymmetry and intermediate-mode L = 24 capsule roughness on the implosion performance of ignition capsule are investigated by two-dimensional radiation hydrodynamic simulations. It is shown that the amplitudes of new modes generated by the mode coupling are in good agreement with the second-order mode coupling equation during the acceleration phase. The later flow field not only shows large areal density P2 asymmetry in the main fuel, but also generates large-amplitude spikes and bubbles. In the deceleration phase, the increasing mode coupling generates more new modes, and the perturbation spectrum on the hot spot boundary is mainly from the strong mode interactions rather than the initial perturbation conditions. The combination of the low-mode and high-mode perturbations breaks up the capsule shell, resulting in a significant reduction of the hot spot temperature and implosion performance.

Assessment of the accuracy of coupled cluster perturbation theory for open-shell systems. I. Triples expansions.

Science.gov (United States)

Eriksen, Janus J; Matthews, Devin A; Jørgensen, Poul; Gauss, Jürgen

2016-05-21

The accuracy at which total energies of open-shell atoms and organic radicals may be calculated is assessed for selected coupled cluster perturbative triples expansions, all of which augment the coupled cluster singles and doubles (CCSD) energy by a non-iterative correction for the effect of triple excitations. Namely, the second- through sixth-order models of the recently proposed CCSD(T-n) triples series [J. J. Eriksen et al., J. Chem. Phys. 140, 064108 (2014)] are compared to the acclaimed CCSD(T) model for both unrestricted as well as restricted open-shell Hartree-Fock (UHF/ROHF) reference determinants. By comparing UHF- and ROHF-based statistical results for a test set of 18 modest-sized open-shell species with comparable RHF-based results, no behavioral differences are observed for the higher-order models of the CCSD(T-n) series in their correlated descriptions of closed- and open-shell species. In particular, we find that the convergence rate throughout the series towards the coupled cluster singles, doubles, and triples (CCSDT) solution is identical for the two cases. For the CCSD(T) model, on the other hand, not only its numerical consistency, but also its established, yet fortuitous cancellation of errors breaks down in the transition from closed- to open-shell systems. The higher-order CCSD(T-n) models (orders n > 3) thus offer a consistent and significant improvement in accuracy relative to CCSDT over the CCSD(T) model, equally for RHF, UHF, and ROHF reference determinants, albeit at an increased computational cost.

Assessment of the accuracy of coupled cluster perturbation theory for open-shell systems. I. Triples expansions

Energy Technology Data Exchange (ETDEWEB)

Eriksen, Janus J., E-mail: janusje@chem.au.dk; Jørgensen, Poul [qLEAP Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, DK-8000 Aarhus C (Denmark); Matthews, Devin A. [The Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712 (United States); Gauss, Jürgen [Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, D-55128 Mainz (Germany)

2016-05-21

The accuracy at which total energies of open-shell atoms and organic radicals may be calculated is assessed for selected coupled cluster perturbative triples expansions, all of which augment the coupled cluster singles and doubles (CCSD) energy by a non-iterative correction for the effect of triple excitations. Namely, the second- through sixth-order models of the recently proposed CCSD(T–n) triples series [J. J. Eriksen et al., J. Chem. Phys. 140, 064108 (2014)] are compared to the acclaimed CCSD(T) model for both unrestricted as well as restricted open-shell Hartree-Fock (UHF/ROHF) reference determinants. By comparing UHF- and ROHF-based statistical results for a test set of 18 modest-sized open-shell species with comparable RHF-based results, no behavioral differences are observed for the higher-order models of the CCSD(T–n) series in their correlated descriptions of closed- and open-shell species. In particular, we find that the convergence rate throughout the series towards the coupled cluster singles, doubles, and triples (CCSDT) solution is identical for the two cases. For the CCSD(T) model, on the other hand, not only its numerical consistency, but also its established, yet fortuitous cancellation of errors breaks down in the transition from closed- to open-shell systems. The higher-order CCSD(T–n) models (orders n > 3) thus offer a consistent and significant improvement in accuracy relative to CCSDT over the CCSD(T) model, equally for RHF, UHF, and ROHF reference determinants, albeit at an increased computational cost.

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT BUCKLING EVALUATION METHODS & RESULTS FOR THE PRIMARY TANKS

Energy Technology Data Exchange (ETDEWEB)

MACKEY TC; JOHNSON KI; DEIBLER JE; PILLI SP; RINKER MW; KARRI NK

2007-02-14

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive I-bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads, based on detailed finite element analysis. The analysis must account for the variation in design details and operating conditions between the different DSTs. The analysis must also address the imperfection sensitivity of the primary tank to buckling. (3) Perform a detailed buckling analysis to determine the maximum allowable differential pressure for each of the DST primary tanks at the current specified limits on waste temperature, height, and specific gravity. Based on the I-bolt loads analysis and the small deformations that are predicted at the unfactored limits on vacuum and axial loads, it is very unlikely that the EH-22 scenario (i.e., progressive I-bolt failure leading to global

Effect of flow velocity and temperature on ignition characteristics in laser ignition of natural gas and air mixtures

Science.gov (United States)

Griffiths, J.; Riley, M. J. W.; Borman, A.; Dowding, C.; Kirk, A.; Bickerton, R.

2015-03-01

Laser induced spark ignition offers the potential for greater reliability and consistency in ignition of lean air/fuel mixtures. This increased reliability is essential for the application of gas turbines as primary or secondary reserve energy sources in smart grid systems, enabling the integration of renewable energy sources whose output is prone to fluctuation over time. This work details a study into the effect of flow velocity and temperature on minimum ignition energies in laser-induced spark ignition in an atmospheric combustion test rig, representative of a sub 15 MW industrial gas turbine (Siemens Industrial Turbomachinery Ltd., Lincoln, UK). Determination of minimum ignition energies required for a range of temperatures and flow velocities is essential for establishing an operating window in which laser-induced spark ignition can operate under realistic, engine-like start conditions. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 532 nm wavelength and 4 ns pulse length. Analysis of the influence of flow velocity and temperature on ignition characteristics is presented in terms of required photon flux density, a useful parameter to consider during the development laser ignition systems.

Laser induced plasma methodology for ignition control in direct injection sprays

International Nuclear Information System (INIS)

Pastor, José V.; García-Oliver, José M.; García, Antonio; Pinotti, Mattia

2016-01-01

Highlights: • Laser Induced Plasma Ignition system is designed and applied to a Diesel Spray. • A method for quantification of the system effectiveness and reliability is proposed. • The ignition system is optimized in atmospheric and engine-like conditions. • Higher system effectiveness is reached with higher ambient density. • The system is able to stabilize Diesel combustion compared to auto-ignition cases. - Abstract: New combustion modes for internal combustion engines represent one of the main fields of investigation for emissions control in transportation Industry. However, the implementation of lean fuel mixture condition and low temperature combustion in real engines is limited by different unsolved practical issues. To achieve an appropriate combustion phasing and cycle-to-cycle control of the process, the laser plasma ignition system arises as a valid alternative to the traditional electrical spark ignition system. This paper proposes a methodology to set-up and optimize a laser induced plasma ignition system that allows ensuring reliability through the quantification of the system effectiveness in the plasma generation and positional stability, in order to reach optimal ignition performance. For this purpose, experimental tests have been carried out in an optical test rig. At first the system has been optimized in an atmospheric environment, based on the statistical analysis of the plasma records taken with a high speed camera to evaluate the induction effectiveness and consequently regulate and control the system settings. The same optimization method has then been applied under engine-like conditions, analyzing the effect of thermodynamic ambient conditions on the plasma induction success and repeatability, which have shown to depend mainly on ambient density. Once optimized for selected engine conditions, the laser plasma induction system has been used to ignite a direct injection Diesel spray, and to compare the evolution of combustion

Prolonged Consumption of Sucrose in a Binge-Like Manner, Alters the Morphology of Medium Spiny Neurons in the Nucleus Accumbens Shell.

Directory of Open Access Journals (Sweden)

Paul M Klenowski

2016-03-01

Full Text Available The modern diet has become highly sweetened, resulting in unprecedented levels of sugar consumption, particularly among adolescents. While chronic long-term sugar intake is known to contribute to the development of metabolic disorders including obesity and type II diabetes, little is known regarding the direct consequences of long-term, binge-like sugar consumption on the brain. Because sugar can cause the release of dopamine in the nucleus accumbens (NAc similarly to drugs of abuse, we investigated changes in the morphology of neurons in this brain region following short- (4 weeks and long-term (12 weeks binge-like sucrose consumption using an intermittent two-bottle choice paradigm. We used Golgi-Cox staining to impregnate medium spiny neurons (MSNs from the NAc core and shell of short- and long-term sucrose consuming rats and compared these to age matched water controls. We show that prolonged binge-like sucrose consumption significantly decreased the total dendritic length of NAc shell MSNs compared to age-matched control rats. We also found that the restructuring of these neurons resulted primarily from reduced distal dendritic complexity. Conversely, we observed increased spine densities at the distal branch orders of NAc shell MSNs from long-term sucrose consuming rats. Combined, these results highlight the neuronal effects of prolonged binge-like intake of sucrose on NAc shell MSN morphology.

Discovery of the First Leaking Double-Shell Tank - Hanford Tank 241-AY-102

International Nuclear Information System (INIS)

Harrington, Stephanie J.; Sams, Terry L.

2013-01-01

A routine video inspection of the annulus space between the primary tank and secondary liner of double-shell tank 241-AY-102 was performed in August 2012. During the inspection, unexpected material was discovered. A subsequent video inspection revealed additional unexpected material on the opposite side of the tank, none of which had been observed during inspections performed in December 2006 and January 2007. A formal leak assessment team was established to review the tank's construction and operating histories, and preparations for sampling and analysis began to determine the material's origin. A new sampling device was required to collect material from locations that were inaccessible to the available sampler. Following its design and fabrication, a mock-up test was performed for the new sampling tool to ensure its functionality and capability of performing the required tasks. Within three months of the discovery of the unexpected material, sampling tools were deployed, material was collected, and analyses were performed. Results indicated that some of the unknown material was indicative of soil, whereas the remainder was consistent with tank waste. This, along with the analyses performed by the leak assessment team on the tank's construction history, lead to the conclusion that the primary tank was leaking into the annulus. Several issues were encountered during the deployment of the samplers into the annulus. As this was the first time samples had been required from the annulus of a double-shell tank, a formal lessons learned was created concerning designing equipment for unique purposes under time constraints

The Expanding Bipolar Conic Shell of the Symbiotic Star AG Peg

Science.gov (United States)

Lee, Seong-Jae; Hyung, Siek

2018-06-01

Symbiotic stars are the most interesting since some systems are believed to host the most massive white dwarf, like SN Ia progenitors. Most recently, Lee and Hyung (2018, LH18) proposed a bipolar conic shell structure for the observed high expansion Hα and Hβ line profiles and other double peak lines observed in 1998 September (phase φ = 10.24): the physical conditions for the white dwarf luminosity and the ionized HII zone, responsible for double Gaussian optical lines including Balmer and Lyman line fluxes, were taken from the P-I model with gas density, nH = 109.85 cm-3 , while the column density for the scattering neutral zone was derived from the broader line components based on the result by Monte Carlo simulations. In this investigation, we examined whether the expanding shells of the bipolar conical geometry as proposed by LH18 would be able to form the other Hα and Hβ line profiles observed in other phases, φ = 11.56 and 11.98 (in 2001 August and 2002 August). We look into the kinematical property of the bipolar conic shell structure responsible for the HII and HI zones and then we discuss the secular variation of the broad line feature and the origin of the bipolar cone, i.e., part of a common envelope formed through the mass inflows from the giant star.

Can nature's design be improved upon? High strength, transparent nacre-like nanocomposites with double network of sacrificial cross links.

Science.gov (United States)

Podsiadlo, Paul; Kaushik, Amit K; Shim, Bong Sup; Agarwal, Ashish; Tang, Zhiyong; Waas, Anthony M; Arruda, Ellen M; Kotov, Nicholas A

2008-11-20

The preparation of a high-strength and highly transparent nacre-like nanocomposite via layer-by-layer assembly technique from poly(vinyl alcohol) (PVA) and Na+-montmorillonite clay nanosheets is reported in this article. We show that a high density of weak bonding interactions between the polymer and the clay particles: hydrogen, dipole-induced dipole, and van der Waals undergoing break-reform deformations, can lead to high strength nanocomposites: sigmaUTS approximately 150 MPa and E' approximately 13 GPa. Further introduction of ionic bonds into the polymeric matrix creates a double network of sacrificial bonds which dramatically increases the mechanical properties: sigmaUTS approximately 320 MPa and E' approximately 60 GPa.

Simulation of double-seaming in a two-piece aluminum can

International Nuclear Information System (INIS)

Romanko, Anne; Berry, Dale; Fox, David

2004-01-01

The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can.To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the

Simulation of Double-Seaming in a Two-piece Aluminum Can

Science.gov (United States)

Romanko, Anne; Berry, Dale; Fox, David

2004-06-01

The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can. To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the

Hot-spot mix in ignition-scale inertial confinement fusion targets.

Science.gov (United States)

Regan, S P; Epstein, R; Hammel, B A; Suter, L J; Scott, H A; Barrios, M A; Bradley, D K; Callahan, D A; Cerjan, C; Collins, G W; Dixit, S N; Döppner, T; Edwards, M J; Farley, D R; Fournier, K B; Glenn, S; Glenzer, S H; Golovkin, I E; Haan, S W; Hamza, A; Hicks, D G; Izumi, N; Jones, O S; Kilkenny, J D; Kline, J L; Kyrala, G A; Landen, O L; Ma, T; MacFarlane, J J; MacKinnon, A J; Mancini, R C; McCrory, R L; Meezan, N B; Meyerhofer, D D; Nikroo, A; Park, H-S; Ralph, J; Remington, B A; Sangster, T C; Smalyuk, V A; Springer, P T; Town, R P J

2013-07-26

Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50)  ng and 4000(-2970,+17 160)  ng are observed.

New tuning method of the low-mode asymmetry for ignition capsule implosions

International Nuclear Information System (INIS)

Gu, Jianfa; Dai, Zhensheng; Zou, Shiyang; Song, Peng; Ye, Wenhua; Zheng, Wudi; Gu, Peijun

2015-01-01

In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the hot spot and the surrounding main fuel layer show obvious P2 asymmetries. This may be caused by the large positive P2 radiation flux asymmetry during the peak pulse resulting form the poor propagation of the inner laser beam in the gas-filled hohlraum. The symmetry evolution of ignition capsule implosions is investigated by applying P2 radiation flux asymmetries during different time intervals. A series of two-dimensional simulation results show that a positive P2 flux asymmetry during the peak pulse results in a positive P2 shell ρR asymmetry; while an early time positive P2 flux asymmetry causes a negative P2 in the fuel ρR shape. The opposite evolution behavior of shell ρR asymmetry is used to develop a new tuning method to correct the radiation flux asymmetry during the peak pulse by adding a compensating same-phased P2 drive asymmetry during the early time. The significant improvements of the shell ρR symmetry, hot spot shape, hot spot internal energy, and neutron yield indicate that the tuning method is quite effective. The similar tuning method can also be used to control the early time drive asymmetries

Criticality safety evaluation of disposing of K Basin sludge in double-shell tank AW-105

International Nuclear Information System (INIS)

ROGERS, C.A.

1999-01-01

A criticality safety evaluation is made of the disposal of K Basin sludge in double-shell tank (DST) AW-105 located in the 200 east area of Hanford Site. The technical basis is provided for limits and controls to be used in the development of a criticality prevention specification (CPS). A model of K Basin sludge is developed to account for fuel burnup. The iron/uranium mass ration required to ensure an acceptable magrin of subcriticality is determined

Advanced ignition for automotive engines

OpenAIRE

Pineda, Daniel Ivan

2017-01-01

Spark plugs have been igniting combustible mixtures like those found in automotive engines for over a century, and the principles of the associated ignition techniques using thermal plasma (inductive or capacitive sparks) have remained relatively unchanged during that time. However, internal combustion engines are increasingly operating with boosted intake pressures (i.e. turbo- or super-charged) in order to maintain power output while simultaneously reducing engine size and weight, and they ...

Ammonia in simulated Hanford double-shell tank wastes: Solubility and effects on surface tension

International Nuclear Information System (INIS)

Norton, J.D.; Pederson, L.R.

1994-09-01

Radioactive and wastes left from defense materials production activities are temporarily stored in large underground tanks at the Hanford Site in south central Washington State (Tank Waste Science Panel 1991). Some of these wastes are in the form of a thick slurry (''double-shell slurry'') containing sodium nitrate, sodium nitrite, sodium aluminate, sodium hydroxide, sodium carbonate, organic complexants and buffering agents, complexant fragments and other minor components (Herting et al. 1992a; Herting et al. 1992b; Campbell et al. 1994). As a result of thermal and radiolytic processes, a number of gases are known to be produced by some of these stored wastes, including ammonia, nitrous oxide, nitrogen, hydrogen, and methane (Babad et al. 1991; Ashby et al. 1992; Meisel et al. 1993; Ashby et al. 1993; Ashby et al. 1994; Bryan et al. 1993; US Department of Energy 1994). Before the emplacement of a mixer pump, these gases were retained in and periodically released from Tank 241-SY-101, a double-shell tank at the Hanford Site (Babad et al. 1992; US Department of Energy 1994). Gases are believed to be retained primarily in the form of bubbles attached to solid particles (Bryan, Pederson, and Scheele 1992), with very little actually dissolved in the liquid. Ammonia is an exception. The relation between the concentration of aqueous ammonia in such concentrated, caustic mixtures and the ammonia partial pressure is not well known, however

Numerical Investigation of a Gasoline-Like Fuel in a Heavy-Duty Compression Ignition Engine Using Global Sensitivity Analysis

Energy Technology Data Exchange (ETDEWEB)

Pal, Pinaki; Probst, Daniel; Pei, Yuanjiang; Zhang, Yu; Traver, Michael; Cleary, David; Som, Sibendu

2017-03-28

Fuels in the gasoline auto-ignition range (Research Octane Number (RON) > 60) have been demonstrated to be effective alternatives to diesel fuel in compression ignition engines. Such fuels allow more time for mixing with oxygen before combustion starts, owing to longer ignition delay. Moreover, by controlling fuel injection timing, it can be ensured that the in-cylinder mixture is “premixed enough” before combustion occurs to prevent soot formation while remaining “sufficiently inhomogeneous” in order to avoid excessive heat release rates. Gasoline compression ignition (GCI) has the potential to offer diesel-like efficiency at a lower cost and can be achieved with fuels such as low-octane straight run gasoline which require significantly less processing in the refinery compared to today’s fuels. To aid the design and optimization of a compression ignition (CI) combustion system using such fuels, a global sensitivity analysis (GSA) was conducted to understand the relative influence of various design parameters on efficiency, emissions and heat release rate. The design parameters included injection strategies, exhaust gas recirculation (EGR) fraction, temperature and pressure at intake valve closure and injector configuration. These were varied simultaneously to achieve various targets of ignition timing, combustion phasing, overall burn duration, emissions, fuel consumption, peak cylinder pressure and maximum pressure rise rate. The baseline case was a three-dimensional closed-cycle computational fluid dynamics (CFD) simulation with a sector mesh at medium load conditions. Eleven design parameters were considered and ranges of variation were prescribed to each of these. These input variables were perturbed in their respective ranges using the Monte Carlo (MC) method to generate a set of 256 CFD simulations and the targets were calculated from the simulation results. GSA was then applied as a screening tool to identify the input parameters having the most

Thickness, Doping Accuracy, and Roughness Control in Graded Germanium Doped Ch{sub x} Micro-shells for Lmj

Energy Technology Data Exchange (ETDEWEB)

Legay, G.; Theobald, M.; Barnouin, J.; Peche, E.; Bednarczyk, S.; Hermerel, C. [CEA Valduc, Dept Rech Mat Nucl, Serv Microcibles, 21 - Is-sur-Tille (France)

2009-05-15

In the Commissariat a l'Energie Atomique Laser Megajoule (LMJ) facility, amorphous hydrogenated carbon (a-C: H or CH{sub x}) is the nominal ablator used to achieve inertial confinement fusion experiments. These targets are filled with of fusible mixture of deuterium-tritium in order to perform ignition. The a-C: H shell is deposited on a poly-alpha-methylstyrene (PAMS) mandrel by glow discharge polymerization with trans-2-butene, hydrogen, and helium. Graded germanium doped CH{sub x} micro-shells are supposed to be more stable regarding hydrodynamic instabilities. The shells are composed of four layers for a total thickness of 180 {mu}m. The germanium gradient is obtained by doping the different a-C: H layers with the addition of tetra-methylgermanium in the gas mixture. As the achievement of ignition greatly depends on the physical properties of the shell, the thicknesses, doping concentration, and roughness must be precisely controlled. Quartz microbalances were used to perform an in situ and real-time measurement of the thickness in order to reduce the variations and so our fabrication tolerances on each layer thickness. Ex situ control of the thickness of each layer was carried out, with both optical coherent tomography and interferometry, (wall-mapper). High-quality, PAMS and a rolling system have been used to lower the low-mode roughness [root-mean-square (rms) (mode 2) {<=} 70 nm]. High modes were clearly, reduced by, coating the pan containing the shells with polyvinyl alcohol + CH{sub x} instead of polystyrene + CH{sub x} resulting in an rms ({>=}mode 10) {<=} 20 nm, which can be {<=}15 nm for the best micro-shells. The germanium concentration (0. 4 and 0. 75 at. %) in the a-CH layer is obtained by regulating the tetramethyl-germanium flow. Low range mass flow controllers have been used to improve the doping accuracy. (authors)

Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner.

Science.gov (United States)

Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

2011-01-15

Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 °C. First, its auto-ignition temperature is measured 365 °C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 °C to 255 °C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor. Copyright © 2010 Elsevier B.V. All rights reserved.

Plasma physics study and laser development for the fast ignition realization experiment (FIREX) project

International Nuclear Information System (INIS)

Azechi, H.; Mima, K.; Fujimoto, Y.

2008-10-01

Since the approval of the first phase of Fast Ignition Realization Experiment (FIREX-I), we have devoted our efforts on designing advanced targets and constructing the world highest-energy Peta Watt laser. The new target design has the following features. The coupling efficiency from the heating laser to the thermal energy of the compressed core plasma can be increased by the two ways:1) Low-Z foam layer on the inner surface of the cone for optimum absorption. 2) Double cone. Electrons generated in the inner surface of the double cone will return by sheathe potential generated between two cones. The implosion performance can be improved by three ways: 3) Low-Z plastic layer on the outer surface of the cone may suppress the expansion of the Au cone that flows into the interior of the compressed core. 4) Br doped plastic ablator may significantly moderate the Rayleigh-Taylor instability, making implosion more stable. 5) Evacuation of the target center to prevent gas jets from destroying the cone tip. For project robustness, we also explore 6) impact ignition scheme that eliminates complexity of laser-plasma interaction while keeping the compactness advantage of fast ignition. The fully integrated fast ignition experiment is scheduled on 2009. If subsequent FIREX-II will start as proposed, the ignition and burn will be demonstrated shortly after the ignition at NIF and LMJ, providing a scientific database of both central and fast ignition. (author)

Studies of Carbonization Process on the Production of Durian Peel Biobriquettes with Mixed Biomass Coconut and Palm Shells

Science.gov (United States)

Sari, Ellyta; Pasymi; Khatab, Umar; Desmiarti, Reni; Ariansyah, Rian; Hariadi; Sutra

2018-03-01

Biobriquettes as alternative energy that can replace the role of kerosene. Biobriquettes made from agricultural waste biomass. Biobriquettes durian peel has been researched and developed continuously to obtain optimal quality in terms of calorific value, compressive strength and duration of ignition. In making durian peel biobriquettes needed other biomass mix to sustain duration of Ignition for biobriquettes durian skin quickly burned out. Stages of making biobriquettes durian skin are: material of drying, carbonization of biomass, grinding, mixing with adhesives, and printing. Carbonization process is a process that is important in obtaining the biomass charcoal. Carbonization is done by means of karbonisator pyrolysis. The purpose of this research is to study the process of carbonization to obtain biobriquettes durian skin that of quality in terms of value compressive strength, calorific value, and duration of ignition. Variations that done was kind mix of biomass,coconut shells and palm shells with the massa ratio 2 : 1, type of adhesive used tapioca powder and banana peels, carbonization of temperature 200°C. 300°C and 400 °C. The results showed that the highest compressive strength of the durian skin with a mixture of coconut shell and adhesive tapioca powder and carbonization temperature of 300 °C namely 12,7 g/cm2. The calorific value of the highest on the mix of skin durian with coconut shells and adhesive banana skin with temperature of carbonization 400 °C ie 6040 cal/g, and duration of ignition highest on a mixture of skin durian with coconut shell and adhesive banana skin at a temperature of carbonization 300 °C is 73 minutes.

Thermonuclear targets for direct-drive ignition by a megajoule laser pulse

Energy Technology Data Exchange (ETDEWEB)

Bel’kov, S. A.; Bondarenko, S. V. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation); Vergunova, G. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Garanin, S. G. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation); Gus’kov, S. Yu., E-mail: guskov@sci.lebedev.ru; Demchenko, N. N.; Doskoch, I. Ya.; Kuchugov, P. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Zmitrenko, N. V. [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Rozanov, V. B.; Stepanov, R. V.; Yakhin, R. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2015-10-15

Central ignition of a thin two-layer-shell fusion target that is directly driven by a 2-MJ profiled pulse of Nd laser second-harmonic radiation has been studied. The parameters of the target were selected so as to provide effective acceleration of the shell toward the center, which was sufficient for the onset of ignition under conditions of increased hydrodynamic stability of the ablator acceleration and compression. The aspect ratio of the inner deuterium-tritium layer of the shell does not exceed 15, provided that a major part (above 75%) of the outer layer (plastic ablator) is evaporated by the instant of maximum compression. The investigation is based on two series of numerical calculations that were performed using one-dimensional (1D) hydrodynamic codes. The first 1D code was used to calculate the absorption of the profiled laser-radiation pulse (including calculation of the total absorption coefficient with allowance for the inverse bremsstrahlung and resonance mechanisms) and the spatial distribution of target heating for a real geometry of irradiation using 192 laser beams in a scheme of focusing with a cubo-octahedral symmetry. The second 1D code was used for simulating the total cycle of target evolution under the action of absorbed laser radiation and for determining the thermonuclear gain that was achieved with a given target.

Absolute Hugoniot measurements from a spherically convergent shock using x-ray radiography

Science.gov (United States)

Swift, Damian C.; Kritcher, Andrea L.; Hawreliak, James A.; Lazicki, Amy; MacPhee, Andrew; Bachmann, Benjamin; Döppner, Tilo; Nilsen, Joseph; Collins, Gilbert W.; Glenzer, Siegfried; Rothman, Stephen D.; Kraus, Dominik; Falcone, Roger W.

2018-05-01

The canonical high pressure equation of state measurement is to induce a shock wave in the sample material and measure two mechanical properties of the shocked material or shock wave. For accurate measurements, the experiment is normally designed to generate a planar shock which is as steady as possible in space and time, and a single state is measured. A converging shock strengthens as it propagates, so a range of shock pressures is induced in a single experiment. However, equation of state measurements must then account for spatial and temporal gradients. We have used x-ray radiography of spherically converging shocks to determine states along the shock Hugoniot. The radius-time history of the shock, and thus its speed, was measured by radiographing the position of the shock front as a function of time using an x-ray streak camera. The density profile of the shock was then inferred from the x-ray transmission at each instant of time. Simultaneous measurement of the density at the shock front and the shock speed determines an absolute mechanical Hugoniot state. The density profile was reconstructed using the known, unshocked density which strongly constrains the density jump at the shock front. The radiographic configuration and streak camera behavior were treated in detail to reduce systematic errors. Measurements were performed on the Omega and National Ignition Facility lasers, using a hohlraum to induce a spatially uniform drive over the outside of a solid, spherical sample and a laser-heated thermal plasma as an x-ray source for radiography. Absolute shock Hugoniot measurements were demonstrated for carbon-containing samples of different composition and initial density, up to temperatures at which K-shell ionization reduced the opacity behind the shock. Here we present the experimental method using measurements of polystyrene as an example.

High-frequency cold ignition of fluorescent lamps

International Nuclear Information System (INIS)

Haverlag, M.; Sormani, J.; Heuvelmans, J.; Geven, A.; Kaldenhoven, L.; Heijne, G.; Kraus, A.

2002-01-01

Experimental and theoretical investigations have been performed on the ignition process of low-pressure mercury-noble gas fluorescent lamps operating on a 50 kHz electronic driver circuit. In case the electrodes of the lamp are not heated prior to the ignition process, the ignition process can, under certain conditions, lead to premature fracture of the coiled-coil electrode, which means that the lamp ceases to operate before the emitter is consumed completely. Experimental studies of this process have shown that the erosion process responsible for this premature end-of-life consists of localized sputtering of the tungsten electrode by energetic ions from the glow discharge that is present during the ignition process. In order to understand the basic process that leads to localized sputtering of the electrodes in a glow discharge, a simple glow-discharge fluid model, in combination with a finite-element model of the heat transport in the electrode, has been built. The model shows that thermionic emission can supply a significant fraction of the electrons already at temperatures far below the normal operating temperature in fluorescent lamps. This thermionic emission is responsible for a contraction process. After the beginning of the discharge contraction it takes typically a few milliseconds before the glow-to-arc transition is observed in the lamp voltage and the normal electrode operating temperature is reached. During this time localized sputtering takes place, which eventually leads to coil fracture. (author)

Fusion ignition via a magnetically-assisted fast ignition approach

OpenAIRE

Wang, W. -M.; Gibbon, P.; Sheng, Z. -M.; Li, Y. T.; Zhang, J.

2016-01-01

Significant progress has been made towards laser-driven fusion ignition via different schemes, including direct and indirect central ignition, fast ignition, shock ignition, and impact ignition schemes. However, to reach ignition conditions, there are still various technical and physical challenges to be solved for all these schemes. Here, our multi-dimensional integrated simulation shows that the fast-ignition conditions could be achieved when two 2.8 petawatt heating laser pulses counter-pr...

Lacunary ideal convergence of multiple sequences

Directory of Open Access Journals (Sweden)

Bipan Hazarika

2016-01-01

Full Text Available An ideal I is a family of subsets of N×N which is closed under taking finite unions and subsets of its elements. In this article, the concept of lacunary ideal convergence of double sequences has been introduced. Also the relation between lacunary ideal convergent and lacunary Cauchy double sequences has been established. Furthermore, the notions of lacunary ideal limit point and lacunary ideal cluster points have been introduced and find the relation between these two notions. Finally, we have studied the properties such as solidity, monotonic.

Identification two novel nacrein-like proteins involved in the shell formation of the Pacific oyster Crassostrea gigas.

Science.gov (United States)

Song, Xiaorui; Wang, Xiaotong; Li, Li; Zhang, Guofan

2014-07-01

Nacrein-like proteins have carbonic anhydrase (CA)-like domains, but their coding regions are flanked by inserted repeat sequence, such as Gly-X-Asn. Reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-CA1), possess CA catalytic functions, and play a key role in shell biomineralization. In the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the Pacific oyster Crassostrea gigas. With numerous analyses, it was identified and characterized that both the nacrein-like proteins F1 and F2 were secreted and most closely related to the nacrein-like protein of California mussel Mytilus californianus via phylogenetic analysis. RT-PCR analysis showed that the nacrein-like proteins F1 and F2 were expressed in multiple tissues and the expression levels remarkably rose after entering the spat stage, which were basically consistent with the increase of calcite fractions in the total shell volume. Surprisingly, the Gly-X-Asn repeat domain, which is distinctive in most nacrein-like proteins, was absent in the two newly identified nacrein-like proteins in C. gigas and replaced with a series of acidic amino acids (D/E). Regardless, nacrein-like proteins in mollusks seem to be vital to the deposition of calcium carbonate and likely perform diverse functions.

An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hoover, D. E.; Nikroo, A. [General Atomics, San Diego, California 92121 (United States); Peterson, K. J. [Sandia National Laboratory, Albuquerque, New Mexico 87125 (United States)

2014-07-15

A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF.

An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

International Nuclear Information System (INIS)

Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J.; Hoover, D. E.; Nikroo, A.; Peterson, K. J.

2014-01-01

A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF

Discovery of a New Classical Nova Shell Around a Nova-like Cataclysmic Variable

Science.gov (United States)

Guerrero, Martín A.; Sabin, Laurence; Tovmassian, Gagik; Santamaría, Edgar; Michel, Raul; Ramos-Larios, Gerardo; Alarie, Alexandre; Morisset, Christophe; Bermúdez Bustamante, Luis C.; González, Chantal P.; Wright, Nick J.

2018-04-01

The morphology and optical spectrum of IPHASX J210204.7+471015, a nebula classified as a possible planetary nebula are, however, strikingly similar to those of AT Cnc, a classical nova shell around a dwarf nova. To investigate its true nature, we have obtained high-resolution narrowband [O III] and [N II] images and deep optical spectra. The nebula shows an arc of [N II]-bright knots notably enriched in nitrogen, while an [O III]-bright bow shock is progressing throughout the ISM. Diagnostic line ratios indicate that shocks are associated with the arc and bow shock. The central star of this nebula has been identified by its photometric variability. Time-resolved photometric and spectroscopic data of this source reveal a period of 4.26 hr, which is attributed to a binary system. The optical spectrum is notably similar to that of RW Sex, a cataclysmic variable star (CV) of the UX UMa nova-like (NL) type. Based on these results, we propose that IPHASX J210204.7 + 471015 is a classical nova shell observed around a CV-NL system in quiescence.

Static internal pressure capacity of Hanford Single-Shell Waste Tanks

Energy Technology Data Exchange (ETDEWEB)

Julyk, L.J.

1994-07-19

Underground single-shell waste storage tanks located at the Hanford Site in Richland, Washington, generate gaseous mixtures that could be ignited, challenging the structural integrity of the tanks. The structural capacity of the single-shell tanks to internal pressure is estimated through nonlinear finite-element structural analyses of the reinforced concrete tank. To determine their internal pressure capacity, designs for both the million-gallon and the half-million-gallon tank are evaluated on the basis of gross structural instability.

Static internal pressure capacity of Hanford Single-Shell Waste Tanks

International Nuclear Information System (INIS)

Julyk, L.J.

1994-01-01

Underground single-shell waste storage tanks located at the Hanford Site in Richland, Washington, generate gaseous mixtures that could be ignited, challenging the structural integrity of the tanks. The structural capacity of the single-shell tanks to internal pressure is estimated through nonlinear finite-element structural analyses of the reinforced concrete tank. To determine their internal pressure capacity, designs for both the million-gallon and the half-million-gallon tank are evaluated on the basis of gross structural instability

Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

Science.gov (United States)

Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

2016-12-01

Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

A comparative experimental study on engine operating on premixed charge compression ignition and compression ignition mode

Directory of Open Access Journals (Sweden)

Bhiogade Girish E.

2017-01-01

Full Text Available New combustion concepts have been recently developed with the purpose to tackle the problem of high emissions level of traditional direct injection Diesel engines. A good example is the premixed charge compression ignition combustion. A strategy in which early injection is used causing a burning process in which the fuel burns in the premixed condition. In compression ignition engines, soot (particulate matter and NOx emissions are an extremely unsolved issue. Premixed charge compression ignition is one of the most promising solutions that combine the advantages of both spark ignition and compression ignition combustion modes. It gives thermal efficiency close to the compression ignition engines and resolves the associated issues of high NOx and particulate matter, simultaneously. Premixing of air and fuel preparation is the challenging part to achieve premixed charge compression ignition combustion. In the present experimental study a diesel vaporizer is used to achieve premixed charge compression ignition combustion. A vaporized diesel fuel was mixed with the air to form premixed charge and inducted into the cylinder during the intake stroke. Low diesel volatility remains the main obstacle in preparing premixed air-fuel mixture. Exhaust gas re-circulation can be used to control the rate of heat release. The objective of this study is to reduce exhaust emission levels with maintaining thermal efficiency close to compression ignition engine.

Filamentation of a converging heavy ion beam

International Nuclear Information System (INIS)

Lee, E.P.; Buchanan, H.L.; Rosenbluth, M.N.

1980-01-01

A major concern in the use of heavy ion beams as igniters in pellet fusion systems is the vulnerability of the beam to the transverse flamentation instability. The undesirable consequence of this mode is the transverse heating of the beam to the extent that convergence on the pellet becomes impossible. This work considers the case of a beam injected into a gas filled reactor vessel, where finite pulse length and propagation distance play an important role in limiting growth. Two geometries are analyzed: a nonconverging case where the radius at injection is nearly equal to the desired radius at the pellet, and a converging case in which the injection radius is large and the beam is pre-focused to converge at the target. It is found that a cold beam will be severely disrupted if the product of the magnetic plasma frequency and the propagation distance is much larger than unity

Progress on precision measurements of inner shell transitions in highly charged ions at an ECR ion source

Energy Technology Data Exchange (ETDEWEB)

Szabo, Csilla I.; Indelicato, Paul; LeBigot, Eric-Olivier; Vallette, Alexandre; Amaro, Pedro; Guerra, Mauro; Gumberidze, Alex [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France); Centro de Fisica Atomica, CFA, Departamento de Fisica (Portugal); Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France)

2012-05-25

Inner shell transitions of highly charged ions produced in the plasma of an Electron Cyclotron Resonance Ion Source (ECRIS) were observed the first time by a Double Crystal Spectrometer (DCS). The DCS is a well-used tool in precision x-ray spectroscopy due to its ability of precision wavelength measurement traced back to a relative angle measurement. Because of its requirement for a bright x-ray source the DCS has not been used before in direct measurements of highly charged ions (HCI). Our new precision measurement of inner shell transitions in HCI is not just going to provide new x-ray standards for quantum metrology but can also give information about the plasma in which the ions reside. Ionic temperatures and with that the electron density can be determined by thorough examination of line widths measured with great accuracy.

Study of electron and proton isochoric heating for fast ignition

International Nuclear Information System (INIS)

Key, M.H.; Chen, M.H.; Chung, H.K.; Foord, M.E.; Gregori, G.; Hatchett, S.P.; Koch, J.A.; Lasinski, B.F.; Langdon, B.; MacKinnon, A.J.; Patel, P.; Snavely, R.A.; Tabak, M.; Town, R.; Wilks, S.C.; Akli, K.; Freeman, R.R.; Gu, P.; Hey, D.; Hill, J.M.; King, J.A.; Patel, N.; Zhang, B.; Freeman, R.R.; Stephens, R.B.; Beg, F.; Pasley, J.; Green, J.S.; Lancaster, K.; Murphy, C.D.; Norreys, P.A.; Green, J.S.; Murphy, C.D.; Habara, H.; Kodama, R.; Tanaka, K.; Yabuuchi, T.; Stoeckl, C.; Theobald, W.

2006-01-01

Isochoric heating by electrons has been measured in the two limiting cases of small area thin foils with dominant refluxing and cone-long-wire geometry with negligible refluxing in the wire. Imaging of Cu Kα cone fluorescence, crystal X-ray spectroscopy of Cu K shell emission, and X UV imaging at 68 eV and 256 eV are discussed. Laser power on target was typically 0.5 PW in 0.7 ps. Heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside 30 degrees cone has been studied with the same diagnostic methods plus imaging of proton induced Kα. Conversion efficiency to protons has been measured and modeled. Conclusions from the experiments, links to theoretical understanding and relevance to fast ignition are outlined. (authors)

Gas retention and release behavior in Hanford single-shell waste tanks

Energy Technology Data Exchange (ETDEWEB)

Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

1996-12-01

This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large ({approximately}100 m{sup 3}) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given.

Ignition and fusion burn in fast ignition scheme

International Nuclear Information System (INIS)

Takabe, Hideaki

1998-01-01

The target physics of fast ignition is briefly reviewed by focusing on the ignition and fusion burn in the off-center ignition scheme. By the use of a two dimensional hydrodynamic code with an alpha heating process, the ignition condition is studied. It is shown that the ignition condition of the off-center ignition scheme coincides with that of the the central isochoric model. After the ignition, a nuclear burning wave is seen to burn the cold main fuel with a velocity of 2 - 3 x 10 8 cm/s. The spark energy required for the off-center ignition is 2 - 3 kJ or 10 - 15 kJ for the core density of 400 g/cm 3 or 200 g/cm 3 , respectively. It is demonstrated that a core gain of more than 2,000 is possible for a core energy of 100 kJ with a hot spark energy of 13 kJ. The requirement for the ignition region's heating time is also discussed by modeling a heating source in the 2-D code. (author)

Note: Measuring breakdown characteristics during the hot re-ignition of high intensity discharge lamps using high frequency alternating current voltage.

Science.gov (United States)

van den Bos, R A J M; Sobota, A; Manders, F; Kroesen, G M W

2013-04-01

To investigate the cold and hot re-ignition properties of High Intensity Discharge (HID) lamps in more detail an automated setup was designed in such a way that HID lamps of various sizes and under different background pressures can be tested. The HID lamps are ignited with a ramped sinusoidal voltage signal with frequencies between 60 and 220 kHz and with amplitude up to 7.5 kV. Some initial results of voltage and current measurements on a commercially available HID lamp during hot and cold re-ignition are presented.

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT BUCKLING EVALUATION METHODS AND RESULTS FOR THE PRIMARY TANKS

Energy Technology Data Exchange (ETDEWEB)

MACKEY TC; JOHNSON KI; DEIBLER JE; PILLI SP; RINKER MW; KARRI NK

2009-01-14

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive anchor bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads based on detailed finite element analysis. The analysis must account for the variation in design details and operating conditions between the different DSTs. The analysis must also address the imperfection sensitivity of the primary tank to buckling. (3) Perform a detailed buckling analysis to determine the maximum allowable differential pressure for each of the DST primary tanks at the current specified limits on waste temperature, height, and specific gravity. Based on the concrete anchor bolt loads analysis and the small deformations that are predicted at the unfactored limits on vacuum and axial loads, it is very unlikely that the EH-22 scenario (i.e., progressive anchor bolt

HANFORD DOUBLE-SHELL TANK THERMAL AND SEISMIC PROJECT-BUCKLING EVALUATION METHODS AND RESULTS FOR THE PRIMARY TANKS

International Nuclear Information System (INIS)

Mackey, T.C.; Johnson, K.I.; Deibler, J.E.; Pilli, S.P.; Rinker, M.W.; Karri, N.K.

2009-01-01

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double-shell waste tanks (DSTs), which is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raised by the Office of Environment, Safety, and Health (ES and H) Oversight (EH-22) during a review of work performed on the double-shell tank farms and the operation of the aging waste facility (AWF) primary tank ventilation system. The current buckling review focuses on the following tasks: (1) Evaluate the potential for progressive anchor bolt failure and the appropriateness of the safety factors that were used for evaluating local and global buckling. The analysis will specifically answer the following questions: (a) Can the EH-22 scenario develop if the vacuum is limited to -6.6-inch water gage (w.g.) by a relief valve? (b) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario can develop? (c) What is the appropriate factor of safety required to protect against buckling if the EH-22 scenario cannot develop? (2) Develop influence functions to estimate the axial stresses in the primary tanks for all reasonable combinations of tank loads based on detailed finite element analysis. The analysis must account for the variation in design details and operating conditions between the different DSTs. The analysis must also address the imperfection sensitivity of the primary tank to buckling. (3) Perform a detailed buckling analysis to determine the maximum allowable differential pressure for each of the DST primary tanks at the current specified limits on waste temperature, height, and specific gravity. Based on the concrete anchor bolt loads analysis and the small deformations that are predicted at the unfactored limits on vacuum and axial loads, it is very unlikely that the EH-22 scenario (i.e., progressive anchor

The effect of laser spot shapes on polar-direct-drive implosions on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Weilacher, F.; Radha, P. B., E-mail: rbah@lle.rochester.edu; Collins, T. J. B.; Marozas, J. A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-03-15

Ongoing polar-direct-drive (PDD) implosions on the National Ignition Facility (NIF) [J. D. Lindl and E. I. Moses, Phys. Plasmas 18, 050901 (2011)] use existing NIF hardware, including indirect-drive phase plates. This limits the performance achievable in these implosions. Spot shapes are identified that significantly improve the uniformity of PDD NIF implosions; outer surface deviation is reduced by a factor of 7 at the end of the laser pulse and hot-spot distortion is reduced by a factor of 2 when the shell has converged by a factor of ∼10. As a result, the neutron yield increases by approximately a factor of 2. This set of laser spot shapes is a combination of circular and elliptical spots, along with elliptical spot shapes modulated by an additional higher-intensity ellipse offset from the center of the beam. This combination is motivated in this paper. It is also found that this improved implosion uniformity is obtained independent of the heat conduction model. This work indicates that significant improvement in performance can be obtained robustly with the proposed spot shapes.

The effect of laser spot shapes on polar-direct-drive implosions on the National Ignition Facility

International Nuclear Information System (INIS)

Weilacher, F.; Radha, P. B.; Collins, T. J. B.; Marozas, J. A.

2015-01-01

Ongoing polar-direct-drive (PDD) implosions on the National Ignition Facility (NIF) [J. D. Lindl and E. I. Moses, Phys. Plasmas 18, 050901 (2011)] use existing NIF hardware, including indirect-drive phase plates. This limits the performance achievable in these implosions. Spot shapes are identified that significantly improve the uniformity of PDD NIF implosions; outer surface deviation is reduced by a factor of 7 at the end of the laser pulse and hot-spot distortion is reduced by a factor of 2 when the shell has converged by a factor of ∼10. As a result, the neutron yield increases by approximately a factor of 2. This set of laser spot shapes is a combination of circular and elliptical spots, along with elliptical spot shapes modulated by an additional higher-intensity ellipse offset from the center of the beam. This combination is motivated in this paper. It is also found that this improved implosion uniformity is obtained independent of the heat conduction model. This work indicates that significant improvement in performance can be obtained robustly with the proposed spot shapes

Absence-like and tonic seizures in aspartoacylase/attractin double-mutant mice.

Science.gov (United States)

Gohma, Hiroshi; Kuramoto, Takashi; Matalon, Reuben; Surendran, Sankar; Tyring, Stephen; Kitada, Kazuhiro; Sasa, Masashi; Serikawa, Tadao

2007-04-01

The Spontaneously Epileptic Rat (SER), a double-mutant for tremor and zitter mutations, shows spontaneous occurrences of absence-like and tonic seizures. Several lines of evidence suggest that the combined effect of Aspa and Atrn mutations is the most likely cause of the epileptic phenotype of the SER. To address this issue, we produced a new double-mutant mouse line carrying both homozygous Aspa-knockout and Atrn(mg-3J) mutant alleles. The Aspa/Atrn double-mutant mice exhibited absence-like and tonic seizures that were characterized by the appearance of 5-7 Hz spike-wave-like complexes and low voltage fast waves on EEGs. These results demonstrate directly that the simultaneous loss of the Aspa and Atrn gene functions causes epileptic seizures in the mouse and suggest that both Aspa and Atrn deficiencies might be responsible for epileptic seizures in the SER.

The National Ignition Facility (NIF) and High Energy Density Science Research at LLNL (Briefing Charts)

Science.gov (United States)

2013-06-21

The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL Presentation to: IEEE Pulsed Power and Plasma Science...Conference C. J. Keane Director, NIF User Office June 21, 2013 1491978-1-4673-5168-3/13/$31.00 ©2013 IEEE Report Documentation Page Form ApprovedOMB No...4. TITLE AND SUBTITLE The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL 5a. CONTRACT NUMBER 5b. GRANT

Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

International Nuclear Information System (INIS)

Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

1998-01-01

Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots (∼100 (micro)m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with ρr ∼ 2 g/cm 2 for a small demo/pilot plant producing ∼40 MJ of fusion yield per target, and (2) a large target with ρr ∼ 10 g/cm 2 producing ∼1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q ∼ 26) ion sources for short (∼5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of ∼10 MG fields to provide steep focusing angles close-in to the target (built-in as part of each target); (4) beam space charge

Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

Energy Technology Data Exchange (ETDEWEB)

Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

1998-04-01

Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles

Gas retention and release behavior in Hanford double-shell waste tanks

Energy Technology Data Exchange (ETDEWEB)

Meyer, P.A.; Brewster, M.E.; Bryan, S.A. [and others

1997-05-01

This report describes the current understanding of flammable gas retention and release in Hanford double-shell waste tanks AN-103, AN-104, AN-105, AW-101, SY-101, and SY-103. This knowledge is based on analyses, experimental results, and observations of tank behavior. The applicable data available from the void fraction instrument, retained gas sampler, ball rheometer, tank characterization, and field monitoring are summarized. Retained gas volumes and void fractions are updated with these new data. Using the retained gas compositions from the retained gas sampler, peak dome pressures during a gas burn are calculated as a function of the fraction of retained gas hypothetically released instantaneously into the tank head space. Models and criteria are given for gas generation, initiation of buoyant displacement, and resulting gas release; and predictions are compared with observed tank behavior.

Gas retention and release behavior in Hanford double-shell waste tanks

International Nuclear Information System (INIS)

Meyer, P.A.; Brewster, M.E.; Bryan, S.A.

1997-05-01

This report describes the current understanding of flammable gas retention and release in Hanford double-shell waste tanks AN-103, AN-104, AN-105, AW-101, SY-101, and SY-103. This knowledge is based on analyses, experimental results, and observations of tank behavior. The applicable data available from the void fraction instrument, retained gas sampler, ball rheometer, tank characterization, and field monitoring are summarized. Retained gas volumes and void fractions are updated with these new data. Using the retained gas compositions from the retained gas sampler, peak dome pressures during a gas burn are calculated as a function of the fraction of retained gas hypothetically released instantaneously into the tank head space. Models and criteria are given for gas generation, initiation of buoyant displacement, and resulting gas release; and predictions are compared with observed tank behavior

Mechanical basis of morphogenesis and convergent evolution of spiny seashells