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Sample records for adiabatic explosion model

  1. Thermal explosion hazards on 18650 lithium ion batteries with a VSP2 adiabatic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jhu, Can-Yong [Doctoral Program, Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (NYUST), 123, University Rd., Sec. 3, Douliou, Yunlin 64002, Taiwan, ROC (China); Wang, Yih-Wen, E-mail: g9410825@yuntech.edu.tw [Department of Occupational Safety and Health, Jen-Teh Junior College of Medicine, Nursing and Management, 79-9, Sha-Luen-Hu, Xi-Zhou-Li, Houlong, Miaoli 35664, Taiwan, ROC (China); Shu, Chi-Min [Doctoral Program, Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology (NYUST), 123, University Rd., Sec. 3, Douliou, Yunlin 64002, Taiwan, ROC (China); Chang, Jian-Chuang; Wu, Hung-Chun [Material and Chemical Research Laboratories, Industrial Technology Research Institute (ITRI), Rm. 222, Bldg. 77, 2F, 195, Sec. 4, Chung Hsing Rd., Chutung, Hsinchu 31040, Taiwan, ROC (China)

    2011-08-15

    Thermal abuse behaviors relating to adiabatic runaway reactions in commercial 18650 lithium ion batteries (LiCoO{sub 2}) are being studied in an adiabatic calorimeter, vent sizing package 2 (VSP2). We select four worldwide battery producers, Sony, Sanyo, Samsung and LG, and tested their Li-ion batteries, which have LiCoO{sub 2} cathodes, to determine their thermal instabilities and adiabatic runaway features. The charged (4.2 V) and uncharged (3.7 V) 18650 Li-ion batteries are tested using a VSP2 with a customized stainless steel test can to evaluate their thermal hazard characteristics, such as the initial exothermic temperature (T{sub 0}), the self-heating rate (dT/dt), the pressure rise rate (dP/dt), the pressure-temperature profiles and the maximum temperature (T{sub max}) and pressure (P{sub max}). The T{sub max} and P{sub max} of the charged Li-ion battery during the runaway reaction reach 903.0 {sup o}C and 1565.9 psig (pound-force per square inch gauge), respectively. This result leads to a thermal explosion, and the heat of reaction is 26.2 kJ. The thermokinetic parameters of the reaction of LiCoO{sub 2} batteries are also determined using the Arrhenius model. The thermal reaction mechanism of the Li-ion battery (pack) proved to be an important safety concern for energy storage. Additionally, use of the VSP2 to classify the self-reactive ratings of the various Li-ion batteries demonstrates a new application of the adiabatic calorimetric methodology.

  2. Thermal explosion hazards on 18650 lithium ion batteries with a VSP2 adiabatic calorimeter

    International Nuclear Information System (INIS)

    Jhu, Can-Yong; Wang, Yih-Wen; Shu, Chi-Min; Chang, Jian-Chuang; Wu, Hung-Chun

    2011-01-01

    Thermal abuse behaviors relating to adiabatic runaway reactions in commercial 18650 lithium ion batteries (LiCoO 2 ) are being studied in an adiabatic calorimeter, vent sizing package 2 (VSP2). We select four worldwide battery producers, Sony, Sanyo, Samsung and LG, and tested their Li-ion batteries, which have LiCoO 2 cathodes, to determine their thermal instabilities and adiabatic runaway features. The charged (4.2 V) and uncharged (3.7 V) 18650 Li-ion batteries are tested using a VSP2 with a customized stainless steel test can to evaluate their thermal hazard characteristics, such as the initial exothermic temperature (T 0 ), the self-heating rate (dT/dt), the pressure rise rate (dP/dt), the pressure-temperature profiles and the maximum temperature (T max ) and pressure (P max ). The T max and P max of the charged Li-ion battery during the runaway reaction reach 903.0 o C and 1565.9 psig (pound-force per square inch gauge), respectively. This result leads to a thermal explosion, and the heat of reaction is 26.2 kJ. The thermokinetic parameters of the reaction of LiCoO 2 batteries are also determined using the Arrhenius model. The thermal reaction mechanism of the Li-ion battery (pack) proved to be an important safety concern for energy storage. Additionally, use of the VSP2 to classify the self-reactive ratings of the various Li-ion batteries demonstrates a new application of the adiabatic calorimetric methodology.

  3. Non-adiabatic perturbations in Ricci dark energy model

    International Nuclear Information System (INIS)

    Karwan, Khamphee; Thitapura, Thiti

    2012-01-01

    We show that the non-adiabatic perturbations between Ricci dark energy and matter can grow both on superhorizon and subhorizon scales, and these non-adiabatic perturbations on subhorizon scales can lead to instability in this dark energy model. The rapidly growing non-adiabatic modes on subhorizon scales always occur when the equation of state parameter of dark energy starts to drop towards -1 near the end of matter era, except that the parameter α of Ricci dark energy equals to 1/2. In the case where α = 1/2, the rapidly growing non-adiabatic modes disappear when the perturbations in dark energy and matter are adiabatic initially. However, an adiabaticity between dark energy and matter perturbations at early time implies a non-adiabaticity between matter and radiation, this can influence the ordinary Sachs-Wolfe (OSW) effect. Since the amount of Ricci dark energy is not small during matter domination, the integrated Sachs-Wolfe (ISW) effect is greatly modified by density perturbations of dark energy, leading to a wrong shape of CMB power spectrum. The instability in Ricci dark energy is difficult to be alleviated if the effects of coupling between baryon and photon on dark energy perturbations are included

  4. Dynamics of ionizing shock waves on adiabatic motions of gases

    International Nuclear Information System (INIS)

    Zorev, N.N.; Sklizkov, G.V.; Shikanov, A.S.

    1982-01-01

    Results are presented of an experimental investigation of free (adiabatic) motion of a spherical ionizing wave in deuterium produced by an expanding laser plasma. It is shown that the discrepancy between the free movement of shock waves (which lead to total ionization of the gas) and the Sedov-Taylor model of a spontaneous point explosion is not related to variations in the adiabat exponent γ and the motion occurs for a constant γ=5/3. The effect is ascribed to the influence of the shock wave front structure on the dynamics of its propagation. An analytic expression for the motion of symmetric ionizing shock waves is found which has an accuracy of better than 1%. As a result the adiabat exponent was determined experimentally. A method for determining the energy of a shock wave on the basis of its dynamics of motion is developed which has an accuracy of approximately 5% [ru

  5. Random matrix model of adiabatic quantum computing

    International Nuclear Information System (INIS)

    Mitchell, David R.; Adami, Christoph; Lue, Waynn; Williams, Colin P.

    2005-01-01

    We present an analysis of the quantum adiabatic algorithm for solving hard instances of 3-SAT (an NP-complete problem) in terms of random matrix theory (RMT). We determine the global regularity of the spectral fluctuations of the instantaneous Hamiltonians encountered during the interpolation between the starting Hamiltonians and the ones whose ground states encode the solutions to the computational problems of interest. At each interpolation point, we quantify the degree of regularity of the average spectral distribution via its Brody parameter, a measure that distinguishes regular (i.e., Poissonian) from chaotic (i.e., Wigner-type) distributions of normalized nearest-neighbor spacings. We find that for hard problem instances - i.e., those having a critical ratio of clauses to variables - the spectral fluctuations typically become irregular across a contiguous region of the interpolation parameter, while the spectrum is regular for easy instances. Within the hard region, RMT may be applied to obtain a mathematical model of the probability of avoided level crossings and concomitant failure rate of the adiabatic algorithm due to nonadiabatic Landau-Zener-type transitions. Our model predicts that if the interpolation is performed at a uniform rate, the average failure rate of the quantum adiabatic algorithm, when averaged over hard problem instances, scales exponentially with increasing problem size

  6. Quantum theory of NMR adiabatic pulses and their applications

    International Nuclear Information System (INIS)

    Ke, Y.

    1993-01-01

    Recently explosive developments of in vivo NMR spectroscopy (NMRS) and imaging (NMRI) in biological and medical sciences have resulted in the establishment of NMR as one of the most advanced major technique in life sciences. These developments have created huge demands for a variety of NMR adiabatic pulses with play a very important role in NMR experiments in vivo. In order to develop new NMR adiabatic pulses, a rigorous systematical quantum theory for this kind of pulses is greatly needed. Providing such a theory is one of the important goals of this dissertation. Quantum density matrix theory and product operator method have been used throughout this dissertation. Another goal, which is the major goal of this thesis research, is to use the quantum theory as a guide to develop new NMR adiabatic pulses and their applications. To fill this goal, a technique to construct a new type of adiabatic pulses, narrow band selective adiabatic pulses, has been invented, which is described through the example of constructing an adiabatic DANTE inversion pulse. This new adiabatic pulse is the first narrow band selective adiabatic pulses: Adiabatic homonuclear and heteronuclear spectral editing sequences. Unique to the first pulse sequence is a B 1 -field filter which is built by using two non-refocusing adiabatic full passage pulses to refocus the wanted signal and dephase unwanted signals. This extra filter greatly enhance the editing efficiency. Unlike commonly used heteronuclear spectral editing sequences which depend on the polarization transfer or spectral subtraction by phase cycling techniques, the second pulse sequences accomplishes the editing of heteronuclear J-coupled signals based on the fact that this sequence is transparent to the uncoupled spins and is equivalent a 90 degrees excitation pulse to the heteronuclear J-coupled spins. Experimental results have confirmed the ability of spectral editing with these two new sequences

  7. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R

    2012-01-19

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  8. Adiabatic analysis of collisions. III. Remarks on the spin model

    International Nuclear Information System (INIS)

    Fano, U.

    1979-01-01

    Analysis of a spin-rotation model illustrates how transitions between adiabatic channel states stem from the second, rather than from the first, rate of change of these states, provided that appropriate identification of channels and scaling of the independent variable are used. These remarks, like the earlier development of a post-adiabatic approach, aim at elucidating the surprising success of approximate separation of variables in the treatment of complex mechanical systems

  9. Development of a model for dimethyl ether non-adiabatic reactors to improve methanol conversion

    Energy Technology Data Exchange (ETDEWEB)

    Nasrollahi, Fatemeh [University of Tehran, Tehran (Iran, Islamic Republic of); Bakeri, Gholamreza; Rahimnejad, Mostafa [Babol Noshirvani University of Technology, Babol (Iran, Islamic Republic of); Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia); Imanian, Mahdi [Mohajer Technical University, Isfahan (Iran, Islamic Republic of)

    2013-10-15

    The modeling of adiabatic and non-adiabatic reactors, using three cooling mediums in the shell side of a shell and tube reactor in cocurrent and countercurrent flow regimes has been conducted. The cooling mediums used in this research are saturated water and methanol feed gas to a reactor which is preheated in the shell side and a special type of oil. The results of adiabatic reactor modeling show good compatibility with the data received from a commercial plant. The results of non-adiabatic reactor modeling showed that more methanol conversion can be achieved in a lower length of reactor, even though in some cases the maximum temperature in the tube side of the reactor is more than the deactivation temperature of the catalyst.

  10. Hot-Spot Ignition Mechanisms for Explosives and Propellants

    Science.gov (United States)

    Field, J. E.; Bourne, N. K.; Palmer, S. J. P.; Walley, S. M.

    1992-05-01

    This paper describes the response of explosives to stress and impact and in particular the mechanisms of `hot-spot' production. Samples in the form of single crystals, powder layers, pressed pellets, gels, polymer bonded explosives (PBXs) and propellants have been studied. Techniques used include a drop-weight facility with transparent anvils which allows photography at microsecond framing intervals, an instrumented drop-weight machine, a miniaturized Hopkinson bar system for high strain rate property measurement, laser speckle for studying the deformation and fracture of PBXs, an automated system for analysing speckle patterns and heat sensitive film for recording the positions and temperatures of hot spots. Polishing and staining methods have been developed to observe the microstructure of PBXs and failure during quasi-static loading. Ignition, when it occurred, took place at local hot-spot sites. Evidence is discussed for a variety of ignition mechanisms including adiabatic shear of the explosive, adiabatic heating of trapped gases during cavity collapse, viscous flow, friction, fracture and shear of added particles and triboluminescent discharge.

  11. Numerical modelling of the effect of using multi-explosives on the explosive forming of steel cones

    OpenAIRE

    De Vuyst, T; Kong, K; Djordjevic, N; Vignjevic, R; Campbell, JC; Hughes, K

    2016-01-01

    Modelling and analysis of underwater explosive forming process by using FEM and SPH formulation is presented in this work. The explosive forming of a steel cone is studied. The model setup includes a low carbon steel plate, plate holder, forming die as well as water and C4 explosive. The effect of multiple explosives on rate of targets deformation has been studied. Four different multi-explosives models have been developed and compared to the single explosive model. The formability of the ste...

  12. Calculating overpressure from BLEVE explosions

    Energy Technology Data Exchange (ETDEWEB)

    Planas-Cuchi, E.; Casal, J. [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Chemical Engineering, Centre for Technological Risk Studies; Salla, J.M. [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Heat Engines

    2004-11-01

    Although a certain number of authors have analyzed the prediction of boiling liquid expanding vapour explosion (BLEVE) and fireball effects, only very few of them have proposed methodologies for predicting the overpressure from such explosions. In this paper, the methods previously published are discussed and shown to introduce a significant overestimation due to erroneous thermodynamic assumptions - ideal gas behaviour and isentropic vapour expansion - on which they are based (in fact, they give the maximum value of overpressure which can be caused by a BLEVE). A new approach is proposed, based on the - more realistic - assumption of an adiabatic and irreversible expansion process; the real properties of the substance involved in the explosion are used. The two methods are compared through the application to a given case. (author)

  13. Modelling of an adiabatic trickle-bed reactor with phase change

    DEFF Research Database (Denmark)

    Ramirez Castelan, Carlos Eduardo; Hidalgo-Vivas, Angelica; Brix, Jacob

    2017-01-01

    This paper describes a modelling approach of the behavior of trickle-bed reactors used for catalytic hydrotreating of oil fractions. A dynamic plug-flow heterogeneous one-dimensional adiabatic model was used to describe the main reactions present in the hydrotreating process: hydrodesulfurization...

  14. Non-adiabatic perturbations in multi-component perfect fluids

    Energy Technology Data Exchange (ETDEWEB)

    Koshelev, N.A., E-mail: koshna71@inbox.ru [Ulyanovsk State University, Leo Tolstoy str 42, 432970 (Russian Federation)

    2011-04-01

    The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models.

  15. Non-adiabatic perturbations in multi-component perfect fluids

    International Nuclear Information System (INIS)

    Koshelev, N.A.

    2011-01-01

    The evolution of non-adiabatic perturbations in models with multiple coupled perfect fluids with non-adiabatic sound speed is considered. Instead of splitting the entropy perturbation into relative and intrinsic parts, we introduce a set of symmetric quantities, which also govern the non-adiabatic pressure perturbation in models with energy transfer. We write the gauge invariant equations for the variables that determine on a large scale the non-adiabatic pressure perturbation and the rate of changes of the comoving curvature perturbation. The analysis of evolution of the non-adiabatic pressure perturbation has been made for several particular models

  16. Adiabatic Quantum Transistors

    Directory of Open Access Journals (Sweden)

    Dave Bacon

    2013-06-01

    Full Text Available We describe a many-body quantum system that can be made to quantum compute by the adiabatic application of a large applied field to the system. Prior to the application of the field, quantum information is localized on one boundary of the device, and after the application of the field, this information propagates to the other side of the device, with a quantum circuit applied to the information. The applied circuit depends on the many-body Hamiltonian of the material, and the computation takes place in a degenerate ground space with symmetry-protected topological order. Such “adiabatic quantum transistors” are universal adiabatic quantum computing devices that have the added benefit of being modular. Here, we describe this model, provide arguments for why it is an efficient model of quantum computing, and examine these many-body systems in the presence of a noisy environment.

  17. Monte Carlo modeling of Lead-Cooled Fast Reactor in adiabatic equilibrium state

    Energy Technology Data Exchange (ETDEWEB)

    Stanisz, Przemysław, E-mail: pstanisz@agh.edu.pl; Oettingen, Mikołaj, E-mail: moettin@agh.edu.pl; Cetnar, Jerzy, E-mail: cetnar@mail.ftj.agh.edu.pl

    2016-05-15

    Graphical abstract: - Highlights: • We present the Monte Carlo modeling of the LFR in the adiabatic equilibrium state. • We assess the adiabatic equilibrium fuel composition using the MCB code. • We define the self-adjusting process of breeding gain by the control rod operation. • The designed LFR can work in the adiabatic cycle with zero fuel breeding. - Abstract: Nuclear power would appear to be the only energy source able to satisfy the global energy demand while also achieving a significant reduction of greenhouse gas emissions. Moreover, it can provide a stable and secure source of electricity, and plays an important role in many European countries. However, nuclear power generation from its birth has been doomed by the legacy of radioactive nuclear waste. In addition, the looming decrease in the available resources of fissile U235 may influence the future sustainability of nuclear energy. The integrated solution to both problems is not trivial, and postulates the introduction of a closed-fuel cycle strategy based on breeder reactors. The perfect choice of a novel reactor system fulfilling both requirements is the Lead-Cooled Fast Reactor operating in the adiabatic equilibrium state. In such a state, the reactor converts depleted or natural uranium into plutonium while consuming any self-generated minor actinides and transferring only fission products as waste. We present the preliminary design of a Lead-Cooled Fast Reactor operating in the adiabatic equilibrium state with the Monte Carlo Continuous Energy Burnup Code – MCB. As a reference reactor model we apply the core design developed initially under the framework of the European Lead-cooled SYstem (ELSY) project and refined in the follow-up Lead-cooled European Advanced DEmonstration Reactor (LEADER) project. The major objective of the study is to show to what extent the constraints of the adiabatic cycle are maintained and to indicate the phase space for further improvements. The analysis

  18. Assessment of total efficiency in adiabatic engines

    Science.gov (United States)

    Mitianiec, W.

    2016-09-01

    The paper presents influence of ceramic coating in all surfaces of the combustion chamber of SI four-stroke engine on working parameters mainly on heat balance and total efficiency. Three cases of engine were considered: standard without ceramic coating, fully adiabatic combustion chamber and engine with different thickness of ceramic coating. Consideration of adiabatic or semi-adiabatic engine was connected with mathematical modelling of heat transfer from the cylinder gas to the cooling medium. This model takes into account changeable convection coefficient based on the experimental formulas of Woschni, heat conductivity of multi-layer walls and also small effect of radiation in SI engines. The simulation model was elaborated with full heat transfer to the cooling medium and unsteady gas flow in the engine intake and exhaust systems. The computer program taking into account 0D model of engine processes in the cylinder and 1D model of gas flow was elaborated for determination of many basic engine thermodynamic parameters for Suzuki DR-Z400S 400 cc SI engine. The paper presents calculation results of influence of the ceramic coating thickness on indicated pressure, specific fuel consumption, cooling and exhaust heat losses. Next it were presented comparisons of effective power, heat losses in the cooling and exhaust systems, total efficiency in function of engine rotational speed and also comparison of temperature inside the cylinder for standard, semi-adiabatic and full adiabatic engine. On the basis of the achieved results it was found higher total efficiency of adiabatic engines at 2500 rpm from 27% for standard engine to 37% for full adiabatic engine.

  19. Thermal explosion models

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Tso Chin [Malaya Univ., Kuala Lumpur (Malaysia)

    1984-12-01

    The phenomenon of thermal explosion arises in several important safety problems, yet scientists are still baffled by its origin. This article reviews some of the models that have been proposed to explain the phenomenon.

  20. Adiabatic equilibrium models for direct containment heating

    International Nuclear Information System (INIS)

    Pilch, M.; Allen, M.D.

    1991-01-01

    Probabilistic risk assessment (PRA) studies are being extended to include a wider spectrum of reactor plants than was considered in NUREG-1150. There is a need for simple direct containment heating (DCH) models that can be used for screening studies aimed at identifying potentially significant contributors to overall risk in individual nuclear power plants. This paper presents two adiabatic equilibrium models suitable for the task. The first, a single-cell model, places a true upper bound on DCH loads. This upper bound, however, often far exceeds reasonable expectations of containment loads based on CONTAIN calculations and experiment observations. In this paper, a two cell model is developed that captures the major mitigating feature of containment compartmentalization, thus providing more reasonable estimates of the containment load

  1. Mathematical Model of a Lithium-Bromide/Water Absorption Refrigeration System Equipped with an Adiabatic Absorber

    Directory of Open Access Journals (Sweden)

    Salem M. Osta-Omar

    2016-11-01

    Full Text Available The objective of this paper is to develop a mathematical model for thermodynamic analysis of an absorption refrigeration system equipped with an adiabatic absorber using a lithium-bromide/water (LiBr/water pair as the working fluid. The working temperature of the generator, adiabatic absorber, condenser, evaporator, the cooling capacity of the system, and the ratio of the solution mass flow rate at the circulation pump to that at the solution pump are used as input data. The model evaluates the thermodynamic properties of all state points, the heat transfer in each component, the various mass flow rates, and the coefficient of performance (COP of the cycle. The results are used to investigate the effect of key parameters on the overall performance of the system. For instance, increasing the generator temperatures and decreasing the adiabatic absorber temperatures can increase the COP of the cycle. The results of this mathematical model can be used for designing and sizing new LiBr/water absorption refrigeration systems equipped with an adiabatic absorber or for optimizing existing aforementioned systems.

  2. Thermal explosion models

    International Nuclear Information System (INIS)

    Tso Chin Ping

    1984-01-01

    The phenomenon of thermal explosion arises in several important safety problems, yet scientists are still baffled by its origin. This article reviews some of the models that have been proposed to explain the phenomenon. (author)

  3. Phenomenological modelling of steam explosions

    International Nuclear Information System (INIS)

    Corradini, M.L.; Drumheller, D.S.

    1980-01-01

    During a hypothetical core meltdown accident, an important safety issue to be addressed is the potential for steam explosions. This paper presents analysis and modelling of experimental results. There are four observations that can be drawn from the analysis: (1) vapor explosions are suppressed by noncondensible gases generated by fuel oxidation, by high ambient pressure, and by high water temperatures; (2) these effects appear to be trigger-related in that an explosion can again be induced in some cases by increasing the trigger magnitude; (3) direct fuel liquid-coolant liquid contact can explain small scale fuel fragmentation; (4) heat transfer during the expansion phase of the explosion can reduce the work potential

  4. Modelling of vapour explosion in stratified geometrie

    International Nuclear Information System (INIS)

    Picchi, St.

    1999-01-01

    When a hot liquid comes into contact with a colder volatile liquid, one can obtain in some conditions an explosive vaporization, told vapour explosion, whose consequences can be important on neighbouring structures. This explosion needs the intimate mixing and the fine fragmentation between the two liquids. In a stratified vapour explosion, these two liquids are initially superposed and separated by a vapor film. A triggering of the explosion can induce a propagation of this along the film. A study of experimental results and existent models has allowed to retain the following main points: - the explosion propagation is due to a pressure wave propagating through the medium; - the mixing is due to the development of Kelvin-Helmholtz instabilities induced by the shear velocity between the two liquids behind the pressure wave. The presence of the vapour in the volatile liquid explains experimental propagation velocity and the velocity difference between the two fluids at the pressure wave crossing. A first model has been proposed by Brayer in 1994 in order to describe the fragmentation and the mixing of the two fluids. Results of the author do not show explosion propagation. We have therefore built a new mixing-fragmentation model based on the atomization phenomenon that develops itself during the pressure wave crossing. We have also taken into account the transient aspect of the heat transfer between fuel drops and the volatile liquid, and elaborated a model of transient heat transfer. These two models have been introduced in a multi-components, thermal, hydraulic code, MC3D. Results of calculation show a qualitative and quantitative agreement with experimental results and confirm basic options of the model. (author)

  5. Piecewise adiabatic following in non-Hermitian cycling

    Science.gov (United States)

    Gong, Jiangbin; Wang, Qing-hai

    2018-05-01

    The time evolution of periodically driven non-Hermitian systems is in general nonunitary but can be stable. It is hence of considerable interest to examine the adiabatic following dynamics in periodically driven non-Hermitian systems. We show in this work the possibility of piecewise adiabatic following interrupted by hopping between instantaneous system eigenstates. This phenomenon is first observed in a computational model and then theoretically explained, using an exactly solvable model, in terms of the Stokes phenomenon. In the latter case, the piecewise adiabatic following is shown to be a genuine critical behavior and the precise phase boundary in the parameter space is located. Interestingly, the critical boundary for piecewise adiabatic following is found to be unrelated to the domain for exceptional points. To characterize the adiabatic following dynamics, we also advocate a simple definition of the Aharonov-Anandan (AA) phase for nonunitary cyclic dynamics, which always yields real AA phases. In the slow driving limit, the AA phase reduces to the Berry phase if adiabatic following persists throughout the driving without hopping, but oscillates violently and does not approach any limit in cases of piecewise adiabatic following. This work exposes the rich features of nonunitary dynamics in cases of slow cycling and should stimulate future applications of nonunitary dynamics.

  6. Decoherence in adiabatic quantum computation

    Science.gov (United States)

    Albash, Tameem; Lidar, Daniel A.

    2015-06-01

    Recent experiments with increasingly larger numbers of qubits have sparked renewed interest in adiabatic quantum computation, and in particular quantum annealing. A central question that is repeatedly asked is whether quantum features of the evolution can survive over the long time scales used for quantum annealing relative to standard measures of the decoherence time. We reconsider the role of decoherence in adiabatic quantum computation and quantum annealing using the adiabatic quantum master-equation formalism. We restrict ourselves to the weak-coupling and singular-coupling limits, which correspond to decoherence in the energy eigenbasis and in the computational basis, respectively. We demonstrate that decoherence in the instantaneous energy eigenbasis does not necessarily detrimentally affect adiabatic quantum computation, and in particular that a short single-qubit T2 time need not imply adverse consequences for the success of the quantum adiabatic algorithm. We further demonstrate that boundary cancellation methods, designed to improve the fidelity of adiabatic quantum computing in the closed-system setting, remain beneficial in the open-system setting. To address the high computational cost of master-equation simulations, we also demonstrate that a quantum Monte Carlo algorithm that explicitly accounts for a thermal bosonic bath can be used to interpolate between classical and quantum annealing. Our study highlights and clarifies the significantly different role played by decoherence in the adiabatic and circuit models of quantum computing.

  7. Modeling non-adiabatic photoexcited reaction dynamics in condensed phases

    International Nuclear Information System (INIS)

    Coker, D.F.

    2003-01-01

    Reactions of photoexcited molecules, ions, and radicals in condensed phase environments involve non-adiabatic dynamics over coupled electronic surfaces. We focus on how local environmental symmetries can effect non-adiabatic coupling between excited electronic states and thus influence, in a possibly controllable way, the outcome of photo-excited reactions. Semi-classical and mixed quantum-classical non-adiabatic molecular dynamics methods, together with semi-empirical excited state potentials are used to probe the dynamical mixing of electronic states in different environments from molecular clusters, to simple liquids and solids, and photo-excited reactions in complex reaction environments such as zeolites

  8. Kinetic Models for Adiabatic Reversible Expansion of a Monatomic Ideal Gas.

    Science.gov (United States)

    Chang, On-Kok

    1983-01-01

    A fixed amount of an ideal gas is confined in an adiabatic cylinder and piston device. The relation between temperature and volume in initial/final phases can be derived from the first law of thermodynamics. However, the relation can also be derived based on kinetic models. Several of these models are discussed. (JN)

  9. Mathematical modelling of the decomposition of explosives

    International Nuclear Information System (INIS)

    Smirnov, Lev P

    2010-01-01

    Studies on mathematical modelling of the molecular and supramolecular structures of explosives and the elementary steps and overall processes of their decomposition are analyzed. Investigations on the modelling of combustion and detonation taking into account the decomposition of explosives are also considered. It is shown that solution of problems related to the decomposition kinetics of explosives requires the use of a complex strategy based on the methods and concepts of chemical physics, solid state physics and theoretical chemistry instead of empirical approach.

  10. Modelling and simulation of gas explosions in complex geometries

    Energy Technology Data Exchange (ETDEWEB)

    Saeter, Olav

    1998-12-31

    This thesis presents a three-dimensional Computational Fluid Dynamics (CFD) code (EXSIM94) for modelling and simulation of gas explosions in complex geometries. It gives the theory and validates the following sub-models : (1) the flow resistance and turbulence generation model for densely packed regions, (2) the flow resistance and turbulence generation model for single objects, and (3) the quasi-laminar combustion model. It is found that a simple model for flow resistance and turbulence generation in densely packed beds is able to reproduce the medium and large scale MERGE explosion experiments of the Commission of European Communities (CEC) within a band of factor 2. The model for a single representation is found to predict explosion pressure in better agreement with the experiments with a modified k-{epsilon} model. This modification also gives a slightly improved grid independence for realistic gas explosion approaches. One laminar model is found unsuitable for gas explosion modelling because of strong grid dependence. Another laminar model is found to be relatively grid independent and to work well in harmony with the turbulent combustion model. The code is validated against 40 realistic gas explosion experiments. It is relatively grid independent in predicting explosion pressure in different offshore geometries. It can predict the influence of ignition point location, vent arrangements, different geometries, scaling effects and gas reactivity. The validation study concludes with statistical and uncertainty analyses of the code performance. 98 refs., 96 figs, 12 tabs.

  11. Hierarchical theory of quantum adiabatic evolution

    International Nuclear Information System (INIS)

    Zhang, Qi; Wu, Biao; Gong, Jiangbin

    2014-01-01

    Quantum adiabatic evolution is a dynamical evolution of a quantum system under slow external driving. According to the quantum adiabatic theorem, no transitions occur between nondegenerate instantaneous energy eigenstates in such a dynamical evolution. However, this is true only when the driving rate is infinitesimally small. For a small nonzero driving rate, there are generally small transition probabilities between the energy eigenstates. We develop a classical mechanics framework to address the small deviations from the quantum adiabatic theorem order by order. A hierarchy of Hamiltonians is constructed iteratively with the zeroth-order Hamiltonian being determined by the original system Hamiltonian. The kth-order deviations are governed by a kth-order Hamiltonian, which depends on the time derivatives of the adiabatic parameters up to the kth-order. Two simple examples, the Landau–Zener model and a spin-1/2 particle in a rotating magnetic field, are used to illustrate our hierarchical theory. Our analysis also exposes a deep, previously unknown connection between classical adiabatic theory and quantum adiabatic theory. (paper)

  12. Development of Adiabatic Doppler Feedback Model in 3D space time analysis Code ARCH

    International Nuclear Information System (INIS)

    Dwivedi, D.K.; Gupta, Anurag

    2015-01-01

    Integrated 3D space-time neutron kinetics with thermal-hydraulic feedback code system is being developed for transient analysis of Compact High Temperature Reactor (CHTR) and Advanced Heavy Water Reactor (AHWR). ARCH (code for Analysis of Reactor transients in Cartesian and Hexagon geometries) has been developed with IQS module for efficient 3D space time analysis. Recently, an adiabatic Doppler (fuel temperature) feedback module has been incorporated in this ARCH-IQS version of tile code. In the adiabatic model of fuel temperature feedback, the transfer of the excess heat from the fuel to the coolant during transient is neglected. The viability of Doppler feedback in ARCH-IQS with adiabatic heating has been checked with AER benchmark (Dyn002). Analyses of anticipated transient without scram (ATWS) case in CHTR as well as in AHWR have been performed with adiabatic fuel temperature feedback. The methodology and results have been presented in this paper. (author)

  13. Adiabatic instability in coupled dark energy/dark matter models

    International Nuclear Information System (INIS)

    Bean, Rachel; Flanagan, Eanna E.; Trodden, Mark

    2008-01-01

    We consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the Universe. Such theories can possess an adiabatic regime in which the quintessence field always sits at the minimum of its effective potential, which is set by the local dark matter density. We show that if the coupling strength is much larger than gravitational, then the adiabatic regime is always subject to an instability. The instability, which can also be thought of as a type of Jeans instability, is characterized by a negative sound speed squared of an effective coupled dark matter/dark energy fluid, and results in the exponential growth of small scale modes. We discuss the role of the instability in specific coupled cold dark matter and mass varying neutrino models of dark energy and clarify for these theories the regimes in which the instability can be evaded due to nonadiabaticity or weak coupling.

  14. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K

    2005-01-01

    Hydronamics of Explosion presents the research results for the problems of underwater explosions and contains a detailed analysis of the structure and the parameters of the wave fields generated by explosions of cord and spiral charges, a description of the formation mechanisms for a wide range of cumulative flows at underwater explosions near the free surface, and the relevant mathematical models. Shock-wave transformation in bubbly liquids, shock-wave amplification due to collision and focusing, and the formation of bubble detonation waves in reactive bubbly liquids are studied in detail. Particular emphasis is placed on the investigation of wave processes in cavitating liquids, which incorporates the concepts of the strength of real liquids containing natural microinhomogeneities, the relaxation of tensile stress, and the cavitation fracture of a liquid as the inversion of its two-phase state under impulsive (explosive) loading. The problems are classed among essentially nonlinear processes that occur unde...

  15. Dissipation in adiabatic quantum computers: lessons from an exactly solvable model

    Science.gov (United States)

    Keck, Maximilian; Montangero, Simone; Santoro, Giuseppe E.; Fazio, Rosario; Rossini, Davide

    2017-11-01

    We introduce and study the adiabatic dynamics of free-fermion models subject to a local Lindblad bath and in the presence of a time-dependent Hamiltonian. The merit of these models is that they can be solved exactly, and will help us to study the interplay between nonadiabatic transitions and dissipation in many-body quantum systems. After the adiabatic evolution, we evaluate the excess energy (the average value of the Hamiltonian) as a measure of the deviation from reaching the final target ground state. We compute the excess energy in a variety of different situations, where the nature of the bath and the Hamiltonian is modified. We find robust evidence of the fact that an optimal working time for the quantum annealing protocol emerges as a result of the competition between the nonadiabatic effects and the dissipative processes. We compare these results with the matrix-product-operator simulations of an Ising system and show that the phenomenology we found also applies for this more realistic case.

  16. Quantum tunneling in the adiabatic Dicke model

    International Nuclear Information System (INIS)

    Chen Gang; Chen Zidong; Liang Jiuqing

    2007-01-01

    The Dicke model describes N two-level atoms interacting with a single-mode bosonic field and exhibits a second-order phase transition from the normal to the superradiant phase. The energy levels are not degenerate in the normal phase but have degeneracy in the superradiant phase, where quantum tunneling occurs. By means of the Born-Oppenheimer approximation and the instanton method in quantum field theory, the tunneling splitting, inversely proportional to the tunneling rate for the adiabatic Dicke model, in the superradiant phase can be evaluated explicitly. It is shown that the tunneling splitting vanishes as exp(-N) for large N, whereas for small N it disappears as √(N)/exp(N). The dependence of the tunneling splitting on the relevant parameters, especially on the atom-field coupling strength, is also discussed

  17. Energy consumption for shortcuts to adiabaticity

    Science.gov (United States)

    Torrontegui, E.; Lizuain, I.; González-Resines, S.; Tobalina, A.; Ruschhaupt, A.; Kosloff, R.; Muga, J. G.

    2017-08-01

    Shortcuts to adiabaticity let a system reach the results of a slow adiabatic process in a shorter time. We propose to quantify the "energy cost" of the shortcut by the energy consumption of the system enlarged by including the control device. A mechanical model where the dynamics of the system and control device can be explicitly described illustrates that a broad range of possible values for the consumption is possible, including zero (above the adiabatic energy increment) when friction is negligible and the energy given away as negative power is stored and reused by perfect regenerative braking.

  18. Thermal hazard assessment of AN and AN-based explosives.

    Science.gov (United States)

    Turcotte, R; Lightfoot, P D; Fouchard, R; Jones, D E G

    2003-07-04

    Ammonium nitrate (AN) is an essential ingredient in most fertilizers. It is also widely used in the commercial explosives industry. In this latter application, it is mostly mixed with fuel oil to form the most popular commercial explosive: ANFO. In both the fertilizer and the explosive industry, aqueous AN solutions (ANS) of various concentrations are processed. These solutions also form the basis of ammonium nitrate emulsion explosives (also called ammonium nitrate emulsions or ANE), which are produced either in bulk or in packaged form. For all these AN-based products, quantities of the order of 20,000kg are being manufactured, transported, stored, and processed at elevated temperatures and/or elevated pressures. Correspondingly, major accidents involving overheating of large quantities of these products have happened in several of these operations. In comparison, convenient laboratory quantities to investigate thermal decomposition properties are generally less than 1kg. As a result, in order to provide information applicable to real-life situations, any laboratory study must use techniques that minimize heat losses from the samples to their environment. In the present study, two laboratory-scale calorimeters providing an adiabatic environment were used: an accelerating rate calorimeter (ARC) and an adiabatic Dewar calorimeter (ADC). Experiments were performed on pure AN, ANFO, various ANS systems, and typical bulk and packaged ANE systems. The effects of sample mass, atmosphere, and formulation on the resulting onset temperatures were studied. A comparison of the results from the two techniques is provided and a proposed method to extrapolate these results to large-scale inventories is examined.

  19. A model of vulcanian explosions

    International Nuclear Information System (INIS)

    Woods, A.W.

    1995-01-01

    We present a model of the initial stages of the explosive eruption of magma from a volcanic conduit as occurs in Vulcanian style eruptions. We assume there is a volatile rich (1-10 wt%) mixture of magma, vaporised groundwater and exsolved volatiles, trapped at high pressure (1-100 atm) just below a plug in a volcanic conduit. If the plug disrupts, there is an explosive eruption in which a rarefaction wave propagates into the conduit allowing the volatile rich mixture to expand and discharge into the atmosphere ahead of the vent. Typically, the explosions are so rapid that coarse grained ejecta (>0.5 mm) do not remain in thermal equilibrium with the gas, and this leads to significantly lower velocities and temperatures than predicted by an equilibrium model. Material may erupt from the vent at speeds of 100-400 m s -1 with an initial mass flux of order 10 7 -10 9 kg s -1 , consistent with video observations of eruptions and measurements of the ballistic dispersal of large clasts. (orig.)

  20. Generalized shortcuts to adiabaticity and enhanced robustness against decoherence

    Science.gov (United States)

    Santos, Alan C.; Sarandy, Marcelo S.

    2018-01-01

    Shortcuts to adiabaticity provide a general approach to mimic adiabatic quantum processes via arbitrarily fast evolutions in Hilbert space. For these counter-diabatic evolutions, higher speed comes at higher energy cost. Here, the counter-diabatic theory is employed as a minimal energy demanding scheme for speeding up adiabatic tasks. As a by-product, we show that this approach can be used to obtain infinite classes of transitionless models, including time-independent Hamiltonians under certain conditions over the eigenstates of the original Hamiltonian. We apply these results to investigate shortcuts to adiabaticity in decohering environments by introducing the requirement of a fixed energy resource. In this scenario, we show that generalized transitionless evolutions can be more robust against decoherence than their adiabatic counterparts. We illustrate this enhanced robustness both for the Landau-Zener model and for quantum gate Hamiltonians.

  1. Mesoscale modeling of metal-loaded high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Bdzil, John Bohdan [Los Alamos National Laboratory; Lieberthal, Brandon [UNIV OF ILLINOIS; Srewart, Donald S [UNIV OF ILLINOIS

    2010-01-01

    We describe a 3D approach to modeling multi-phase blast explosive, which is primarily condensed explosive by volume with inert embedded particles. These embedded particles are uniform in size and placed on the array of a regular lattice. The asymptotic theory of detonation shock dynamics governs the detonation shock propagation in the explosive. Mesoscale hydrodynamic simulations are used to show how the particles are compressed, deformed, and accelerated by the high-speed detonation products flow.

  2. Early light curves for Type Ia supernova explosion models

    Science.gov (United States)

    Noebauer, U. M.; Kromer, M.; Taubenberger, S.; Baklanov, P.; Blinnikov, S.; Sorokina, E.; Hillebrandt, W.

    2017-12-01

    Upcoming high-cadence transient survey programmes will produce a wealth of observational data for Type Ia supernovae. These data sets will contain numerous events detected very early in their evolution, shortly after explosion. Here, we present synthetic light curves, calculated with the radiation hydrodynamical approach STELLA for a number of different explosion models, specifically focusing on these first few days after explosion. We show that overall the early light curve evolution is similar for most of the investigated models. Characteristic imprints are induced by radioactive material located close to the surface. However, these are very similar to the signatures expected from ejecta-CSM or ejecta-companion interaction. Apart from the pure deflagration explosion models, none of our synthetic light curves exhibit the commonly assumed power-law rise. We demonstrate that this can lead to substantial errors in the determination of the time of explosion. In summary, we illustrate with our calculations that even with very early data an identification of specific explosion scenarios is challenging, if only photometric observations are available.

  3. Glass produced by underground nuclear explosions

    International Nuclear Information System (INIS)

    Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

    1983-01-01

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10 12 calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 μm scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity

  4. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  5. Non-adiabatic pumping in an oscillating-piston model

    Science.gov (United States)

    Chuchem, Maya; Dittrich, Thomas; Cohen, Doron

    2012-05-01

    We consider the prototypical "piston pump" operating on a ring, where a circulating current is induced by means of an AC driving. This can be regarded as a generalized Fermi-Ulam model, incorporating a finite-height moving wall (piston) and non-trivial topology (ring). The amount of particles transported per cycle is determined by a layered structure of phase space. Each layer is characterized by a different drift velocity. We discuss the differences compared with the adiabatic and Boltzmann pictures, and highlight the significance of the "diabatic" contribution that might lead to a counter-stirring effect.

  6. High-temperature explosive development for geothermal well stimulation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E.W.; Mars, J.E.; Wang, C.

    1978-03-31

    A two-component, temperature-resistant liquid explosive called HITEX has been developed which is capable of withstanding 561/sup 0/K (550/sup 0/F) for 24 hours in a geothermal environment. The explosive is intended for the stimulation of nonproducing or marginally producing geothermal (hot dry rock, vapor-dominated or hydrothermal) reservoirs by fracturing the strata in the vicinity of a borehole. The explosive is inherently safe because it is mixed below ground downhole from two nondetonable liquid components. Development and safety tests included differential scanning calorimetry, thermal stability, minerals compatibility, drop-weight sensitivity, adiabatic compression, electrostatic discharge sensitivity, friction sensitivity, detonation arrest capability, cook-off tests, detonability at ambient and elevated pressure, detonation velocity and thin film propagation in a wedge.

  7. Modelling of vapour explosion in a stratified geometry

    International Nuclear Information System (INIS)

    Brayer, Claude

    1994-01-01

    A vapour explosion is the explosive vaporisation of a volatile liquid in contact with another hotter liquid. Such a violent vaporisation requires an intimate mixing and a fine fragmentation of both liquids. Based on a synthesis of published experimental results, the author of this research thesis reports the development of a new physical model which describes the explosion. In this model, the explosion propagation is due to the propagation of the pressure wave associated with this this explosion, all along the vapour film which initially separates both liquids. The author takes the presence of water in the liquid initially located over the film into account. This presence of vapour explains experimental propagation rates. Another consequence, when the pressure wave passes, is an acceleration of liquids at different rates below and above the film. The author considers that a mixture layer then forms from the point of disappearance of the film, between both liquids, and that fragmentation is due to the turbulence in this mixture layer. This fragmentation model is then introduced into an Euler thermodynamic, three-dimensional and multi-constituents code of calculation, MC3D, to study the influence of fragmentation on thermal exchanges between the various constituents on the volatile liquid vaporisation [fr

  8. Modeling the explosion-source region: An overview

    International Nuclear Information System (INIS)

    Glenn, L.A.

    1993-01-01

    The explosion-source region is defined as the region surrounding an underground explosion that cannot be described by elastic or anelastic theory. This region extends typically to ranges up to 1 km/(kt) 1/3 but for some purposes, such as yield estimation via hydrodynamic means (CORRTEX and HYDRO PLUS), the maximum range of interest is less by an order of magnitude. For the simulation or analysis of seismic signals, however, what is required is the time resolved motion and stress state at the inelastic boundary. Various analytic approximations have been made for these boundary conditions, but since they rely on near-field empirical data they cannot be expected to reliably extrapolate to different explosion sites. More important, without some knowledge of the initial energy density and the characteristics of the medium immediately surrounding the explosion, these simplified models are unable to distinguish chemical from nuclear explosions, identify cavity decoupling, or account for such phenomena as anomalous dissipation via pore collapse

  9. Adiabatic cooling processes in frustrated magnetic systems with pyrochlore structure

    Science.gov (United States)

    Jurčišinová, E.; Jurčišin, M.

    2017-11-01

    We investigate in detail the process of adiabatic cooling in the framework of the exactly solvable antiferromagnetic spin-1/2 Ising model in the presence of the external magnetic field on an approximate lattice with pyrochlore structure. The behavior of the entropy of the model is studied and exact values of the residual entropies of all ground states are found. The temperature variation of the system under adiabatic (de)magnetization is investigated and the central role of the macroscopically degenerated ground states in cooling processes is explicitly demonstrated. It is shown that the model parameter space of the studied geometrically frustrated system is divided into five disjunct regions with qualitatively different processes of the adiabatic cooling. The effectiveness of the adiabatic (de)magnetization cooling in the studied model is compared to the corresponding processes in paramagnetic salts. It is shown that the processes of the adiabatic cooling in the antiferromagnetic frustrated systems are much more effective especially in nonzero external magnetic fields. It means that the frustrated magnetic materials with pyrochlore structure can be considered as very promising refrigerants mainly in the situations with nonzero final values of the magnetic field.

  10. Five-component propagation model for steam explosion analysis

    International Nuclear Information System (INIS)

    Yang, Y.; Moriyama, Kiyofumi; Park, H.S.; Maruyama, Yu; Sugimoto, Jun

    1999-01-01

    A five-field simulation code JASMINE-pro has been developed at JAERI for the calculation of the propagation and explosion phase of steam explosions. The basic equations and the constitutive relationships specifically utilized in the propagation models in the code are introduced in this paper. Some calculations simulating the KROTOS 1D and 2D steam explosion experiments are also stated in the paper to show the present capability of the code. (author)

  11. HERMES: A Model to Describe Deformation, Burning, Explosion, and Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Reaugh, J E

    2011-11-22

    HERMES (High Explosive Response to MEchanical Stimulus) was developed to fill the need for a model to describe an explosive response of the type described as BVR (Burn to Violent Response) or HEVR (High Explosive Violent Response). Characteristically this response leaves a substantial amount of explosive unconsumed, the time to reaction is long, and the peak pressure developed is low. In contrast, detonations characteristically consume all explosive present, the time to reaction is short, and peak pressures are high. However, most of the previous models to describe explosive response were models for detonation. The earliest models to describe the response of explosives to mechanical stimulus in computer simulations were applied to intentional detonation (performance) of nearly ideal explosives. In this case, an ideal explosive is one with a vanishingly small reaction zone. A detonation is supersonic with respect to the undetonated explosive (reactant). The reactant cannot respond to the pressure of the detonation before the detonation front arrives, so the precise compressibility of the reactant does not matter. Further, the mesh sizes that were practical for the computer resources then available were large with respect to the reaction zone. As a result, methods then used to model detonations, known as {beta}-burn or program burn, were not intended to resolve the structure of the reaction zone. Instead, these methods spread the detonation front over a few finite-difference zones, in the same spirit that artificial viscosity is used to spread the shock front in inert materials over a few finite-difference zones. These methods are still widely used when the structure of the reaction zone and the build-up to detonation are unimportant. Later detonation models resolved the reaction zone. These models were applied both to performance, particularly as it is affected by the size of the charge, and to situations in which the stimulus was less than that needed for reliable

  12. Transitionless driving on adiabatic search algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sangchul, E-mail: soh@qf.org.qa [Qatar Environment and Energy Research Institute, Qatar Foundation, Doha (Qatar); Kais, Sabre, E-mail: kais@purdue.edu [Qatar Environment and Energy Research Institute, Qatar Foundation, Doha (Qatar); Department of Chemistry, Department of Physics and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-12-14

    We study quantum dynamics of the adiabatic search algorithm with the equivalent two-level system. Its adiabatic and non-adiabatic evolution is studied and visualized as trajectories of Bloch vectors on a Bloch sphere. We find the change in the non-adiabatic transition probability from exponential decay for the short running time to inverse-square decay in asymptotic running time. The scaling of the critical running time is expressed in terms of the Lambert W function. We derive the transitionless driving Hamiltonian for the adiabatic search algorithm, which makes a quantum state follow the adiabatic path. We demonstrate that a uniform transitionless driving Hamiltonian, approximate to the exact time-dependent driving Hamiltonian, can alter the non-adiabatic transition probability from the inverse square decay to the inverse fourth power decay with the running time. This may open up a new but simple way of speeding up adiabatic quantum dynamics.

  13. Mesoscale meteorological model based on radioactive explosion cloud simulation

    International Nuclear Information System (INIS)

    Zheng Yi; Zhang Yan; Ying Chuntong

    2008-01-01

    In order to simulate nuclear explosion and dirty bomb radioactive cloud movement and concentration distribution, mesoscale meteorological model RAMS was used. Particles-size, size-active distribution and gravitational fallout in the cloud were considered. The results show that the model can simulate the 'mushroom' clouds of explosion. Three-dimension fluid field and radioactive concentration field were received. (authors)

  14. Bipolar explosion models for hypernovae

    International Nuclear Information System (INIS)

    Maeda, Keiichi; Nomoto, Ken'ichi

    2003-01-01

    Bipolar explosion models for hypernovae (very energetic supernovae) are presented. These models provide a favorable situation to explain some unexpected features in observations of hypernovae, e.g., high velocity matter dominated by Fe and low velocity matter dominated by O. The overall abundance of these models gives a good fit, at least qualitatively, to abundances in extremely metal-poor stars. We suggest hypernovae be driven by bipolar jets and contribute significantly to the early Galactic chemical evolution

  15. Dynamic and Thermodynamic Properties of a CA Engine with Non-Instantaneous Adiabats

    Directory of Open Access Journals (Sweden)

    Ricardo T. Paéz-Hernández

    2017-11-01

    Full Text Available This paper presents an analysis of a Curzon and Alhborn thermal engine model where both internal irreversibilities and non-instantaneous adiabatic branches are considered, operating with maximum ecological function and maximum power output regimes. Its thermodynamic properties are shown, and an analysis of its local dynamic stability is performed. The results derived are compared throughout the work with the results obtained previously for a case in which the adiabatic branches were assumed as instantaneous. The results indicate a better performance for thermodynamic properties in the model with instantaneous adiabatic branches, whereas there is an improvement in robustness in the case where non-instantaneous adiabatic branches are considered.

  16. Theoretical model of the early phases of an underground explosion

    International Nuclear Information System (INIS)

    Cameron, I.G.; Scorgie, G.C.

    1970-01-01

    Introduction In the early phases of the intense underground explosions contemplated in peaceful applications the rock near the explosive exhibits fluid behaviour; at great distances its behaviour can usefully be investigated in terms of linear elasticity; and at intermediate distances we think of a solid exhibiting various inelastic effects including cracking and tensile fracture. The present paper outlines a mathematical model that attempts to include in some degree the main features of this range of behaviour. A more detailed treatment than is given here, and its relationship to the work of others, is given in a paper by the authors. A computer program ATHENE has been written based on this model and its use is illustrated by examining some aspects of two types of explosions. One is a chemical explosion which eventually formed a crater and the other a nuclear explosion which remained wholly contained

  17. Theoretical model of the early phases of an underground explosion

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, I G; Scorgie, G C [Atomic Weapons Research Establishment, Aldermaston, Berkshire (United Kingdom)

    1970-05-01

    Introduction In the early phases of the intense underground explosions contemplated in peaceful applications the rock near the explosive exhibits fluid behaviour; at great distances its behaviour can usefully be investigated in terms of linear elasticity; and at intermediate distances we think of a solid exhibiting various inelastic effects including cracking and tensile fracture. The present paper outlines a mathematical model that attempts to include in some degree the main features of this range of behaviour. A more detailed treatment than is given here, and its relationship to the work of others, is given in a paper by the authors. A computer program ATHENE has been written based on this model and its use is illustrated by examining some aspects of two types of explosions. One is a chemical explosion which eventually formed a crater and the other a nuclear explosion which remained wholly contained.

  18. Thermal hazard assessment of AN and AN-based explosives

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, T.; Lightfoot, P. D.; Fouchard, R.; Jones, D. E. G. [Natural Resources Canada, CANMET Canadian Explosives Research Laboratory, Ottawa, ON (Canada)

    2002-12-01

    Ammonium-based aqeous solutions of various concentrations are processed in both the fertilizer and explosives industry, and ammonium nitrate emulsions form the basis of bulk ammonium nitrate emulsion explosives. Major accidents involving overheating of large quantities of these products are not uncommon. To provide guidance to handling large bulk quantities of these materials laboratory experiments must be carried out in such a way as to minimize heat losses from the samples. In this study experiments were performed on pure ammonium, the popular commercial explosive ANFO, various aqueous ammonium solutions and typical bulk and packaged ammonium nitrate emulsions, using two laboratory-scale calorimeters (accelerating rate calorimeter and adiabatic Dewar calorimeter). The objective of the experiments was to study the effects of sample mass, atmosphere, and formulation on the resulting onset temperatures. Result from the two techniques were compared and a method for extrapolating these results to large-scale inventories was proposed. 22 refs., 4 tabs., 14 figs.

  19. Comparing droplet activation parameterisations against adiabatic parcel models using a novel inverse modelling framework

    Science.gov (United States)

    Partridge, Daniel; Morales, Ricardo; Stier, Philip

    2015-04-01

    Many previous studies have compared droplet activation parameterisations against adiabatic parcel models (e.g. Ghan et al., 2001). However, these have often involved comparisons for a limited number of parameter combinations based upon certain aerosol regimes. Recent studies (Morales et al., 2014) have used wider ranges when evaluating their parameterisations, however, no study has explored the full possible multi-dimensional parameter space that would be experienced by droplet activations within a global climate model (GCM). It is important to be able to efficiently highlight regions of the entire multi-dimensional parameter space in which we can expect the largest discrepancy between parameterisation and cloud parcel models in order to ascertain which regions simulated by a GCM can be expected to be a less accurate representation of the process of cloud droplet activation. This study provides a new, efficient, inverse modelling framework for comparing droplet activation parameterisations to more complex cloud parcel models. To achieve this we couple a Markov Chain Monte Carlo algorithm (Partridge et al., 2012) to two independent adiabatic cloud parcel models and four droplet activation parameterisations. This framework is computationally faster than employing a brute force Monte Carlo simulation, and allows us to transparently highlight which parameterisation provides the closest representation across all aerosol physiochemical and meteorological environments. The parameterisations are demonstrated to perform well for a large proportion of possible parameter combinations, however, for certain key parameters; most notably the vertical velocity and accumulation mode aerosol concentration, large discrepancies are highlighted. These discrepancies correspond for parameter combinations that result in very high/low simulated values of maximum supersaturation. By identifying parameter interactions or regimes within the multi-dimensional parameter space we hope to guide

  20. Studies in Chaotic adiabatic dynamics

    International Nuclear Information System (INIS)

    Jarzynski, C.

    1994-01-01

    Chaotic adiabatic dynamics refers to the study of systems exhibiting chaotic evolution under slowly time-dependent equations of motion. In this dissertation the author restricts his attention to Hamiltonian chaotic adiabatic systems. The results presented are organized around a central theme, namely, that the energies of such systems evolve diffusively. He begins with a general analysis, in which he motivates and derives a Fokker-Planck equation governing this process of energy diffusion. He applies this equation to study the open-quotes goodnessclose quotes of an adiabatic invariant associated with chaotic motion. This formalism is then applied to two specific examples. The first is that of a gas of noninteracting point particles inside a hard container that deforms slowly with time. Both the two- and three-dimensional cases are considered. The results are discussed in the context of the Wall Formula for one-body dissipation in nuclear physics, and it is shown that such a gas approaches, asymptotically with time, an exponential velocity distribution. The second example involves the Fermi mechanism for the acceleration of cosmic rays. Explicit evolution equations are obtained for the distribution of cosmic ray energies within this model, and the steady-state energy distribution that arises when this equation is modified to account for the injection and removal of cosmic rays is discussed. Finally, the author re-examines the multiple-time-scale approach as applied to the study of phase space evolution under a chaotic adiabatic Hamiltonian. This leads to a more rigorous derivation of the above-mentioned Fokker-Planck equation, and also to a new term which has relevance to the problem of chaotic adiabatic reaction forces (the forces acting on slow, heavy degrees of freedom due to their coupling to light, fast chaotic degrees)

  1. Simulating a topological transition in a superconducting phase qubit by fast adiabatic trajectories

    Science.gov (United States)

    Wang, Tenghui; Zhang, Zhenxing; Xiang, Liang; Gong, Zhihao; Wu, Jianlan; Yin, Yi

    2018-04-01

    The significance of topological phases has been widely recognized in the community of condensed matter physics. The well controllable quantum systems provide an artificial platform to probe and engineer various topological phases. The adiabatic trajectory of a quantum state describes the change of the bulk Bloch eigenstates with the momentum, and this adiabatic simulation method is however practically limited due to quantum dissipation. Here we apply the "shortcut to adiabaticity" (STA) protocol to realize fast adiabatic evolutions in the system of a superconducting phase qubit. The resulting fast adiabatic trajectories illustrate the change of the bulk Bloch eigenstates in the Su-Schrieffer-Heeger (SSH) model. A sharp transition is experimentally determined for the topological invariant of a winding number. Our experiment helps identify the topological Chern number of a two-dimensional toy model, suggesting the applicability of the fast adiabatic simulation method for topological systems.

  2. Dynamical constraints and adiabatic invariants in chemical reactions.

    Science.gov (United States)

    Lorquet, J C

    2007-08-23

    For long-range electrostatic potentials and, more generally, when the topography of the potential energy surface is locally simple, the reaction path coordinate is adiabatically separable from the perpendicular degrees of freedom. For the ion-permanent dipole and ion-quadrupole interactions, the Poisson bracket of the adiabatic invariant decreases with the interfragment distance more rapidly than the electrostatic potential. The smaller the translational momentum, the moment of inertia of the neutral fragment, and the dipole or quadrupole moments are, the more reliable the adiabatic approximation is, as expected from the usual argumentation. Closed-form expressions for an effective one-dimensional potential in an adiabatic Hamiltonian are given. Connection with a model where the decoupling is exact is obtained in the limit of an infinitely heavy dipole. The dynamics is also constrained by adiabatic invariance for a harmonic valley about a curved reaction path, as shown by the reaction path Hamiltonian method. The maximum entropy method reveals that, as a result of the invariance properties of the entropy, constraints whose validity has been demonstrated locally only subsist in all parts of phase space. However, their form varies continuously, and they are not necessarily expressed in simple terms as they are in the asymptotic region. Therefore, although the influence of adiabatic invariance has been demonstrated at asymptotically large values of the reaction coordinate only, it persists in more interesting ranges.

  3. Adiabatic rotation, quantum search, and preparation of superposition states

    International Nuclear Information System (INIS)

    Siu, M. Stewart

    2007-01-01

    We introduce the idea of using adiabatic rotation to generate superpositions of a large class of quantum states. For quantum computing this is an interesting alternative to the well-studied 'straight line' adiabatic evolution. In ways that complement recent results, we show how to efficiently prepare three types of states: Kitaev's toric code state, the cluster state of the measurement-based computation model, and the history state used in the adiabatic simulation of a quantum circuit. We also show that the method, when adapted for quantum search, provides quadratic speedup as other optimal methods do with the advantages that the problem Hamiltonian is time independent and that the energy gap above the ground state is strictly nondecreasing with time. Likewise the method can be used for optimization as an alternative to the standard adiabatic algorithm

  4. Non-adiabatic pressure loss boundary condition for modelling turbocharger turbine pulsating flow

    International Nuclear Information System (INIS)

    Chiong, M.S.; Rajoo, S.; Romagnoli, A.; Costall, A.W.; Martinez-Botas, R.F.

    2015-01-01

    Highlights: • Bespoke non-adiabatic pressure loss boundary for pulse flow turbine modelling. • Predictions show convincing results against experimental and literature data. • Predicted pulse pressure propagation is in good agreement with literature data. • New methodology is time efficient and requires minimal geometrical inputs. - Abstract: This paper presents a simplified methodology of pulse flow turbine modelling, as an alternative over the meanline integrated methodology outlined in previous work, in order to make its application to engine cycle simulation codes much more straight forward. This is enabled through the development of a bespoke non-adiabatic pressure loss boundary to represent the turbine rotor. In this paper, turbocharger turbine pulse flow performance predictions are presented along with a comparison of computation duration against the previously established integrated meanline method. Plots of prediction deviation indicate that the mass flow rate and actual power predictions from both methods are highly comparable and are reasonably close to experimental data. However, the new boundary condition required significantly lower computational time and rotor geometrical inputs. In addition, the pressure wave propagation in this simplified unsteady turbine model at different pulse frequencies has also been found to be in agreement with data from the literature, thereby supporting the confidence in its ability to simulate the wave action encountered in turbine pulse flow operation

  5. Topology hidden behind the breakdown of adiabaticity

    International Nuclear Information System (INIS)

    Fu, L.-B.; Chen, S.-G.

    2005-01-01

    For classical Hamiltonian systems, the adiabatic condition may fail at some critical points. However, the breakdown of the adiabatic condition does not always cause the adiabatic evolution to be destroyed. In this paper, we suggest a supplemental condition of the adiabatic evolution for the fixed points of classical Hamiltonian systems when the adiabatic condition breaks down at the critical points. As an example, we investigate the adiabatic evolution of the fixed points of a classical Hamiltonian system which has a number of applications

  6. Dzyaloshinskii-Moriya interactions and adiabatic magnetization dynamics in molecular magnets

    NARCIS (Netherlands)

    De Raedt, H; Miyashita, S; Michielsen, K; Machida, M

    A microscopic model of the molecular magnet V-15 is used to study mechanisms for the adiabatic change of the magnetization in time-dependent magnetic fields. The effects of the Dzyaloshinskii-Moriya interaction, the most plausible source for the energy-level repulsions that lead to adiabatic changes

  7. GRAPH MODELING OF THE GRAIN PROCESSING ENTERPRISE FOR SECONDARY EXPLOSION ESTIMATIONS

    Directory of Open Access Journals (Sweden)

    A. S. Popov

    2016-08-01

    Full Text Available Mathematical model for the possible development of the primary explosion at the grain processing enterprise is created. It is proved that only instability is possible for the combustion process. This model enables to estimate possibility of the secondary explosion at any object of the enterprise and forms the base for mathematical support of the decision support system for explosion-proof. Such decision support system can be included in the control system of the processing enterprise.

  8. Predicting the effect of relaxation during frequency-selective adiabatic pulses

    Science.gov (United States)

    Pfaff, Annalise R.; McKee, Cailyn E.; Woelk, Klaus

    2017-11-01

    Adiabatic half and full passages are invaluable for achieving uniform, B1-insensitive excitation or inversion of macroscopic magnetization across a well-defined range of NMR frequencies. To accomplish narrow frequency ranges with adiabatic pulses (computer-calculated data with experimental results demonstrates that, in non-viscous, small-molecule fluids, it is possible to model magnetization and relaxation by considering standard T1 and T2 relaxation in the traditional rotating frame. The proposed model is aimed at performance optimizations of applications in which these pulses are employed. It differs from previous reports which focused on short high-power adiabatic pulses and relaxation that is governed by dipole-dipole interactions, cross polarization, or chemical exchange.

  9. Sensitivity of numerical dispersion modeling to explosive source parameters

    International Nuclear Information System (INIS)

    Baskett, R.L.; Cederwall, R.T.

    1991-01-01

    The calculation of downwind concentrations from non-traditional sources, such as explosions, provides unique challenges to dispersion models. The US Department of Energy has assigned the Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) the task of estimating the impact of accidental radiological releases to the atmosphere anywhere in the world. Our experience includes responses to over 25 incidents in the past 16 years, and about 150 exercises a year. Examples of responses to explosive accidents include the 1980 Titan 2 missile fuel explosion near Damascus, Arkansas and the hydrogen gas explosion in the 1986 Chernobyl nuclear power plant accident. Based on judgment and experience, we frequently estimate the source geometry and the amount of toxic material aerosolized as well as its particle size distribution. To expedite our real-time response, we developed some automated algorithms and default assumptions about several potential sources. It is useful to know how well these algorithms perform against real-world measurements and how sensitive our dispersion model is to the potential range of input values. In this paper we present the algorithms we use to simulate explosive events, compare these methods with limited field data measurements, and analyze their sensitivity to input parameters. 14 refs., 7 figs., 2 tabs

  10. Adiabatic quantum computation

    Science.gov (United States)

    Albash, Tameem; Lidar, Daniel A.

    2018-01-01

    Adiabatic quantum computing (AQC) started as an approach to solving optimization problems and has evolved into an important universal alternative to the standard circuit model of quantum computing, with deep connections to both classical and quantum complexity theory and condensed matter physics. This review gives an account of the major theoretical developments in the field, while focusing on the closed-system setting. The review is organized around a series of topics that are essential to an understanding of the underlying principles of AQC, its algorithmic accomplishments and limitations, and its scope in the more general setting of computational complexity theory. Several variants are presented of the adiabatic theorem, the cornerstone of AQC, and examples are given of explicit AQC algorithms that exhibit a quantum speedup. An overview of several proofs of the universality of AQC and related Hamiltonian quantum complexity theory is given. Considerable space is devoted to stoquastic AQC, the setting of most AQC work to date, where obstructions to success and their possible resolutions are discussed.

  11. Mean-field dynamics of a Bose-Einstein condensate in a time-dependent triple-well trap: Nonlinear eigenstates, Landau-Zener models, and stimulated Raman adiabatic passage

    International Nuclear Information System (INIS)

    Graefe, E. M.; Korsch, H. J.; Witthaut, D.

    2006-01-01

    We investigate the dynamics of a Bose-Einstein condensate in a triple-well trap in a three-level approximation. The interatomic interactions are taken into account in a mean-field approximation (Gross-Pitaevskii equation), leading to a nonlinear three-level model. Additional eigenstates emerge due to the nonlinearity, depending on the system parameters. Adiabaticity breaks down if such a nonlinear eigenstate disappears when the parameters are varied. The dynamical implications of this loss of adiabaticity are analyzed for two important special cases: A three-level Landau-Zener model and the stimulated Raman adiabatic passage (STIRAP) scheme. We discuss the emergence of looped levels for an equal-slope Landau-Zener model. The Zener tunneling probability does not tend to zero in the adiabatic limit and shows pronounced oscillations as a function of the velocity of the parameter variation. Furthermore we generalize the STIRAP scheme for adiabatic coherent population transfer between atomic states to the nonlinear case. It is shown that STIRAP breaks down if the nonlinearity exceeds the detuning

  12. On modelling adiabatic N-soliton interactions and perturbations. Effects of external potentials

    International Nuclear Information System (INIS)

    Gerdjikov, V.; Baizakov, B.

    2005-01-01

    We analyze several perturbed versions of the complex Toda chain (CTC) in an attempt to describe the adiabatic N-soliton train interactions of the perturbed nonlinear Schrodinger equation (NLS). Particular types of perturbations, including quadratic and periodic external potentials are treated by both analytical and numerical means. We show that the perturbed CTC model provides a good description for the N-soliton interactions in the presence of a weak external potential. (authors)

  13. Adiabatic compression of elongated field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1982-01-01

    The simplest model of plasma dynamics is the adiabatic model. In this model the plasma is assumed to be in MHD equilibrium at each instant of time. The equilibria are connected by the requirement that they all have the same entropy per unit flux, i.e., the equilibria form a sequence generated by adiabatic changes. The standard way of computing such a sequence of equilibria was developed by Grad, but its practical use requires a fairly complicated code. It would be helpful if approximately the same results could be gotten either with a much simpler code or by analytical techniques. In Sec. II a one-dimensional equilibrium code is described and its results are checked against a two-dimensional equilibrium code; in Sec. III an even simpler analytic calculation is presented.

  14. Three-dimensional Modeling of Type Ia Supernova Explosions

    Science.gov (United States)

    Khokhlov, Alexei

    2001-06-01

    A deflagration explosion of a Type Ia Supernova (SNIa) is studied using three-dimensional, high-resolution, adaptive mesh refinement fluid dynamic calculations. Deflagration speed in an exploding Chandrasekhar-mass carbon-oxygen white dwarf (WD) grows exponentially, reaches approximately 30the speed of sound, and then declines due to a WD expansion. Outermost layers of the WD remain unburned. The explosion energy is comparable to that of a Type Ia supernova. The freezing of turbulent motions by expansion appears to be a crucial physical mechanism regulating the strength of a supernova explosion. In contrast to one-dimensional models, three-dimensional calculations predict the formation of Si-group elements and pockets of unburned CO in the middle and in central regions of a supernova ejecta. This, and the presence of unburned outer layer of carbon-oxygen may pose problems for SNIa spectra. Explosion sensitivity to initial conditions and its relation to a diversity of SNIa is discussed.

  15. Recent developments in trapping and manipulation of atoms with adiabatic potentials

    Science.gov (United States)

    Garraway, Barry M.; Perrin, Hélène

    2016-09-01

    A combination of static and oscillating magnetic fields can be used to ‘dress’ atoms with radio-frequency (RF), or microwave, radiation. The spatial variation of these fields can be used to create an enormous variety of traps for ultra-cold atoms and quantum gases. This article reviews the type and character of these adiabatic traps and the applications which include atom interferometry and the study of low-dimensional quantum systems. We introduce the main concepts of magnetic traps leading to adiabatic dressed traps. The concept of adiabaticity is discussed in the context of the Landau-Zener model. The first bubble trap experiment is reviewed together with the method used for loading it. Experiments based on atom chips show the production of double wells and ring traps. Dressed atom traps can be evaporatively cooled with an additional RF field, and a weak RF field can be used to probe the spectroscopy of the adiabatic potentials. Several approaches to ring traps formed from adiabatic potentials are discussed, including those based on atom chips, time-averaged adiabatic potentials and induction methods. Several proposals for adiabatic lattices with dressed atoms are also reviewed.

  16. ADIABATIC HEATING OF CONTRACTING TURBULENT FLUIDS

    International Nuclear Information System (INIS)

    Robertson, Brant; Goldreich, Peter

    2012-01-01

    Turbulence influences the behavior of many astrophysical systems, frequently by providing non-thermal pressure support through random bulk motions. Although turbulence is commonly studied in systems with constant volume and mean density, turbulent astrophysical gases often expand or contract under the influence of pressure or gravity. Here, we examine the behavior of turbulence in contracting volumes using idealized models of compressed gases. Employing numerical simulations and an analytical model, we identify a simple mechanism by which the turbulent motions of contracting gases 'adiabatically heat', experiencing an increase in their random bulk velocities until the largest eddies in the gas circulate over a Hubble time of the contraction. Adiabatic heating provides a mechanism for sustaining turbulence in gases where no large-scale driving exists. We describe this mechanism in detail and discuss some potential applications to turbulence in astrophysical settings.

  17. PERFORMANCE EVALUATION OF EMPIRICAL MODELS FOR VENTED LEAN HYDROGEN EXPLOSIONS

    OpenAIRE

    Anubhav Sinha; Vendra C. Madhav Rao; Jennifer X. Wen

    2017-01-01

    Explosion venting is a method commonly used to prevent or minimize damage to an enclosure caused by an accidental explosion. An estimate of the maximum overpressure generated though explosion is an important parameter in the design of the vents. Various engineering models (Bauwens et al., 2012, Molkov and Bragin, 2015) and European (EN 14994 ) and USA standards (NFPA 68) are available to predict such overpressure. In this study, their performance is evaluated using a number of published exper...

  18. Detonation and fragmentation modeling for the description of large scale vapor explosions

    International Nuclear Information System (INIS)

    Buerger, M.; Carachalios, C.; Unger, H.

    1985-01-01

    The thermal detonation modeling of large-scale vapor explosions is shown to be indispensable for realistic safety evaluations. A steady-state as well as transient detonation model have been developed including detailed descriptions of the dynamics as well as the fragmentation processes inside a detonation wave. Strong restrictions for large-scale vapor explosions are obtained from this modeling and they indicate that the reactor pressure vessel would even withstand explosions with unrealistically high masses of corium involved. The modeling is supported by comparisons with a detonation experiment and - concerning its key part - hydronamic fragmentation experiments. (orig.) [de

  19. Adiabatic capture and debunching

    International Nuclear Information System (INIS)

    Ng, K.Y.

    2012-01-01

    In the study of beam preparation for the g-2 experiment, adiabatic debunching and adiabatic capture are revisited. The voltage programs for these adiabbatic processes are derived and their properties discussed. Comparison is made with some other form of adiabatic capture program. The muon g-2 experiment at Fermilab calls for intense proton bunches for the creation of muons. A booster batch of 84 bunches is injected into the Recycler Ring, where it is debunched and captured into 4 intense bunches with the 2.5-MHz rf. The experiment requires short bunches with total width less than 100 ns. The transport line from the Recycler to the muon-production target has a low momentum aperture of ∼ ±22 MeV. Thus each of the 4 intense proton bunches required to have an emittance less than ∼ 3.46 eVs. The incoming booster bunches have total emittance ∼ 8.4 eVs, or each one with an emittance ∼ 0.1 eVs. However, there is always emittance increase when the 84 booster bunches are debunched. There will be even larger emittance increase during adiabatic capture into the buckets of the 2.5-MHz rf. In addition, the incoming booster bunches may have emittances larger than 0.1 eVs. In this article, we will concentrate on the analysis of the adiabatic capture process with the intention of preserving the beam emittance as much as possible. At this moment, beam preparation experiment is being performed at the Main Injector. Since the Main Injector and the Recycler Ring have roughly the same lattice properties, we are referring to adiabatic capture in the Main Injector instead in our discussions.

  20. MC3D modelling of stratified explosion

    International Nuclear Information System (INIS)

    Picchi, S.; Berthoud, G.

    1999-01-01

    It is known that a steam explosion can occur in a stratified geometry and that the observed yields are lower than in the case of explosion in a premixture configuration. However, very few models are available to quantify the amount of melt which can be involved and the pressure peak that can be developed. In the stratified application of the MC3D code, mixing and fragmentation of the melt are explained by the growth of Kelvin Helmholtz instabilities due to the shear flow of the two phase coolant above the melt. Such a model is then used to recalculate the Frost-Ciccarelli tin-water experiment. Pressure peak, speed of propagation, bubble shape and erosion height are well reproduced as well as the influence of the inertial constraint (height of the water pool). (author)

  1. MC3D modelling of stratified explosion

    Energy Technology Data Exchange (ETDEWEB)

    Picchi, S.; Berthoud, G. [DTP/SMTH/LM2, CEA, 38 - Grenoble (France)

    1999-07-01

    It is known that a steam explosion can occur in a stratified geometry and that the observed yields are lower than in the case of explosion in a premixture configuration. However, very few models are available to quantify the amount of melt which can be involved and the pressure peak that can be developed. In the stratified application of the MC3D code, mixing and fragmentation of the melt are explained by the growth of Kelvin Helmholtz instabilities due to the shear flow of the two phase coolant above the melt. Such a model is then used to recalculate the Frost-Ciccarelli tin-water experiment. Pressure peak, speed of propagation, bubble shape and erosion height are well reproduced as well as the influence of the inertial constraint (height of the water pool). (author)

  2. Wireless adiabatic power transfer

    International Nuclear Information System (INIS)

    Rangelov, A.A.; Suchowski, H.; Silberberg, Y.; Vitanov, N.V.

    2011-01-01

    Research highlights: → Efficient and robust mid-range wireless energy transfer between two coils. → The adiabatic energy transfer is analogous to adiabatic passage in quantum optics. → Wireless energy transfer is insensitive to any resonant constraints. → Wireless energy transfer is insensitive to noise in the neighborhood of the coils. - Abstract: We propose a technique for efficient mid-range wireless power transfer between two coils, by adapting the process of adiabatic passage for a coherently driven two-state quantum system to the realm of wireless energy transfer. The proposed technique is shown to be robust to noise, resonant constraints, and other interferences that exist in the neighborhood of the coils.

  3. Ground model and computer complex for designing underground explosions

    Energy Technology Data Exchange (ETDEWEB)

    Bashurov, V.V.; Vakhrameev, Yu.S.; Dem' yanovskii, S.V.; Ignatenko, V.V.; Simonova, T.V.

    1977-01-01

    A description is given of a ground model that accounts for large deformations, their irreversibility, loose rock, breakdown, resistance to internal friction, and other factors. Calculations from the American Sulky explosion and camouflage detonations of two spaced explosive charges are cited as examples illustrating the possibility of design methods and the suitability of ground state equations for describing underground detonations.

  4. A mesoscopic reaction rate model for shock initiation of multi-component PBX explosives.

    Science.gov (United States)

    Liu, Y R; Duan, Z P; Zhang, Z Y; Ou, Z C; Huang, F L

    2016-11-05

    The primary goal of this research is to develop a three-term mesoscopic reaction rate model that consists of a hot-spot ignition, a low-pressure slow burning and a high-pressure fast reaction terms for shock initiation of multi-component Plastic Bonded Explosives (PBX). Thereinto, based on the DZK hot-spot model for a single-component PBX explosive, the hot-spot ignition term as well as its reaction rate is obtained through a "mixing rule" of the explosive components; new expressions for both the low-pressure slow burning term and the high-pressure fast reaction term are also obtained by establishing the relationships between the reaction rate of the multi-component PBX explosive and that of its explosive components, based on the low-pressure slow burning term and the high-pressure fast reaction term of a mesoscopic reaction rate model. Furthermore, for verification, the new reaction rate model is incorporated into the DYNA2D code to simulate numerically the shock initiation process of the PBXC03 and the PBXC10 multi-component PBX explosives, and the numerical results of the pressure histories at different Lagrange locations in explosive are found to be in good agreements with previous experimental data. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Adiabatic quantum computing

    OpenAIRE

    Lobe, Elisabeth; Stollenwerk, Tobias; Tröltzsch, Anke

    2015-01-01

    In the recent years, the field of adiabatic quantum computing has gained importance due to the advances in the realisation of such machines, especially by the company D-Wave Systems. These machines are suited to solve discrete optimisation problems which are typically very hard to solve on a classical computer. Due to the quantum nature of the device it is assumed that there is a substantial speedup compared to classical HPC facilities. We explain the basic principles of adiabatic ...

  6. Adiabatic quantum simulators

    Directory of Open Access Journals (Sweden)

    J. D. Biamonte

    2011-06-01

    Full Text Available In his famous 1981 talk, Feynman proposed that unlike classical computers, which would presumably experience an exponential slowdown when simulating quantum phenomena, a universal quantum simulator would not. An ideal quantum simulator would be controllable, and built using existing technology. In some cases, moving away from gate-model-based implementations of quantum computing may offer a more feasible solution for particular experimental implementations. Here we consider an adiabatic quantum simulator which simulates the ground state properties of sparse Hamiltonians consisting of one- and two-local interaction terms, using sparse Hamiltonians with at most three-local interactions. Properties of such Hamiltonians can be well approximated with Hamiltonians containing only two-local terms. The register holding the simulated ground state is brought adiabatically into interaction with a probe qubit, followed by a single diabatic gate operation on the probe which then undergoes free evolution until measured. This allows one to recover e.g. the ground state energy of the Hamiltonian being simulated. Given a ground state, this scheme can be used to verify the QMA-complete problem LOCAL HAMILTONIAN, and is therefore likely more powerful than classical computing.

  7. Ion Motion in the Adiabatic Focuser

    International Nuclear Information System (INIS)

    Henestroza, E.; Sessler, A.M.; Yu, S.S.

    2006-01-01

    In this paper we numerically study the effect of ion motion in an adiabatic focuser, motivated by a recent suggestion that ion motion in an adiabatic focuser might be significant and even preclude operation of the focuser as previously envisioned. It is shown that despite ion motion the adiabatic focuser should work as well as originally envisioned

  8. The CREST reactive-burn model for explosives

    Directory of Open Access Journals (Sweden)

    Maheswaran M-A.

    2011-01-01

    Full Text Available CREST is an innovative reactive-burn model that has been developed at AWE for simulating shock initiation and detonation propagation behaviour in explosives. The model has a different basis from other reactive-burn models in that its reaction rate is independent of local flow variables behind the shock wave e.g. pressure and temperature. The foundation for CREST, based on a detailed analysis of data from particle-velocity gauge experiments, is that the reaction rate depends only on the local shock strength and the time since the shock passed. Since a measure of shock strength is the entropy of the non-reacted explosive, which remains constant behind a shock, CREST uses an entropy-dependent reaction rate. This paper will provide an overview of the CREST model and its predictive capability. In particular, it will be shown that the model can predict a wide range of experimental phenomena for both shock initiation (e.g. the effects of porosity and initial temperature on sustained-shock and thin-flyer initiation and detonation propagation (e.g. the diameter effect curve and detonation failure cones using a single set of coefficients.

  9. Gas pollutants from detonation and combustion of industrial explosives

    Energy Technology Data Exchange (ETDEWEB)

    Campos, J.; Pines, A.; Gois, J.C.; Portugal, A. (University of Coimbra, Coimbra (Portugal). Mechanical Engineering Dept.)

    1993-01-01

    The potential hazards of fumes, from blasting operations in underground mines, have long been recognised. Beyond this normal use of explosives, there are also large amounts of energy substances which cannot be used because their life time is outdated or they are not within the minimal quality requirements. There is a lack of information concerning tests, procedures and theoretical predictions of pollutant concentrations in fumes from detonation and combustion operations with industrial explosives. The most common industrial explosives in Portugal are ammonium nitrate-fuel oil compositions (anfo), and dynamite. Recently, ammonium nitrate based emulsion explosives are more and more used in industrial applications. This paper presents the structure and fundamental thermodynamic equations of THOR computer code to calculate the combustion and detonation products (CO[sub 2], CO, H[sub 2]O, N[sub 2], O[sub 2], H[sub 2], OH, NO, H, N, O, HCN, NH[sub 3], NO[sub 2], N[sub 2]O, CH[sub 4] gases and two kinds of solid carbon - graphite and diamond) for the minimum value of Gibbs free energy, using three well known equations of state - BKW, H9 and H12. Detonation experiments are described and gas analysis discussed. Measured pollutants concentrations (CO, CO[sub 2], NO and NO[sub 2]), as a function of volume of explosion chamber, prove the dependence of expansion mechanisms on CO and NO formation and recombination and validate theoretical predictions. Incineration of explosives in a fluidised bed is described. Products composition from isobare adiabatic combustion of selected explosives has been calculated and correlated with previous calculations for a detonation regime. The obtained results demonstrate the possibility of predicting gas composition of detonation and combustion products of industrial explosives. 22 refs., 14 figs., 1 tab.

  10. Adiabatic temperature change from non-adiabatic measurements

    Czech Academy of Sciences Publication Activity Database

    Carvalho, A.M.G.; Mejía, C.S.; Ponte, C.A.; Silva, L.E.L.; Kaštil, Jiří; Kamarád, Jiří; Gomes, A.M.

    2016-01-01

    Roč. 122, č. 3 (2016), s. 1-5, č. článku 246. ISSN 0947-8396 Institutional support: RVO:68378271 Keywords : magnetocaloric effect * adiabatic temperature change * calorimetric device * gadolinium Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.455, year: 2016

  11. Effects of neutrino trapping on supernova explosions

    International Nuclear Information System (INIS)

    Takahara, Mariko; Sato, Katsuhiko

    1982-01-01

    Effects of neutrino trapping on the mass ejection from the stellar cores are investigated with the aid of a simplified equation of state under the assumption of adiabatic collapse. It is found that mass ejection becomes violent only if the ratio of the trapped leptons to baryons, Y sub(L), lies in an appropriate range. If the value of Y sub(L) lies out of this range, mass ejection is difficult. It is also shown that as the thermal stiffness of the shocked matter increases, the range necessary for the violent mass ejection becomes wider. Possibilities of supernova explosion are discussed on the basis of these results. (author)

  12. Plasma parameters of the cathode spot explosive electron emission cell obtained from the model of liquid-metal jet tearing and electrical explosion

    Science.gov (United States)

    Tsventoukh, M. M.

    2018-05-01

    A model has been developed for the explosive electron emission cell pulse of a vacuum discharge cathode spot that describes the ignition and extinction of the explosive pulse. The pulse is initiated due to hydrodynamic tearing of a liquid-metal jet which propagates from the preceding cell crater boundary and draws the ion current from the plasma produced by the preceding explosion. Once the jet neck has been resistively heated to a critical temperature (˜1 eV), the plasma starts expanding and decreasing in density, which corresponds to the extinction phase. Numerical and analytical solutions have been obtained that describe both the time behavior of the pulse plasma parameters and their average values. For the cell plasma, the momentum per transferred charge has been estimated to be some tens of g cm/(s C), which is consistent with the known measurements of ion velocity, ion erosion rate, and specific recoil force. This supports the model of the pressure-gradient-driven plasma acceleration mechanism for the explosive cathode spot cells. The ohmic electric field within the explosive current-carrying plasma has been estimated to be some tens of kV/cm, which is consistent with the known experimental data on cathode potential fall and explosive cell plasma size. This supports the model that assumes the ohmic nature of the cathode potential fall in a vacuum discharge.

  13. Toward an Empirically-based Parametric Explosion Spectral Model

    Science.gov (United States)

    Ford, S. R.; Walter, W. R.; Ruppert, S.; Matzel, E.; Hauk, T. F.; Gok, R.

    2010-12-01

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases (Pn, Pg, and Lg) that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. These parameters are then correlated with near-source geology and containment conditions. There is a correlation of high gas-porosity (low strength) with increased spectral slope. However, there are trade-offs between the slope and corner-frequency, which we try to independently constrain using Mueller-Murphy relations and coda-ratio techniques. The relationship between the parametric equation and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source, and aid in the prediction of observed local and regional distance seismic amplitudes for event identification and yield determination in regions with incomplete or no prior history of underground nuclear testing.

  14. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J. F.; Ma, Q. M.; Song, T.; Yuan, S. B. [Research Department of Biomedical Engineering, Institute of Electrical Engineering, Chinese Academy of Science, Beijing 100190 (China); Qin, G., E-mail: wangjunfang@mail.iee.ac.cn, E-mail: qingang@hit.edu.cn [School of Science, Harbin Institute of Technology, Shenzhen 518055 (China)

    2017-08-20

    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  15. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing

    Science.gov (United States)

    Wang, J. F.; Qin, G.; Ma, Q. M.; Song, T.; Yuan, S. B.

    2017-08-01

    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  16. Perpendicular Diffusion Coefficient of Comic Rays: The Presence of Weak Adiabatic Focusing

    International Nuclear Information System (INIS)

    Wang, J. F.; Ma, Q. M.; Song, T.; Yuan, S. B.; Qin, G.

    2017-01-01

    The influence of adiabatic focusing on particle diffusion is an important topic in astrophysics and plasma physics. In the past, several authors have explored the influence of along-field adiabatic focusing on the parallel diffusion of charged energetic particles. In this paper, using the unified nonlinear transport theory developed by Shalchi and the method of He and Schlickeiser, we derive a new nonlinear perpendicular diffusion coefficient for a non-uniform background magnetic field. This formula demonstrates that the particle perpendicular diffusion coefficient is modified by along-field adiabatic focusing. For isotropic pitch-angle scattering and the weak adiabatic focusing limit, the derived perpendicular diffusion coefficient is independent of the sign of adiabatic focusing characteristic length. For the two-component model, we simplify the perpendicular diffusion coefficient up to the second order of the power series of the adiabatic focusing characteristic quantity. We find that the first-order modifying factor is equal to zero and that the sign of the second order is determined by the energy of the particles.

  17. Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

    Science.gov (United States)

    Bulla, Mattia

    2017-02-01

    Despite their relevance across a broad range of astrophysical research topics, Type Ia supernova explosions are still poorly understood and answers to the questions of when, why and how these events are triggered remain unclear. In this respect, polarisation offers a unique opportunity to discriminate between the variety of possible scenarios. The observational evidence that Type Ia supernovae are associated with rather low polarisation signals (smaller than a few per cent) places strong constraints for models and calls for modest asphericities in the progenitor system and/or explosion mechanism.The goal of this thesis is to assess the validity of contemporary Type Ia supernova explosion models by testing whether their predicted polarisation signatures can account for the small signals usually observed. To this end, we have implemented and tested an innovative Monte Carlo scheme in the radiative transfer code artis. Compared to previous Monte Carlo approaches, this technique produces synthetic observables (light curves, flux and polarisation spectra) with a substantial reduction in the Monte Carlo noise and therefore in the required computing time. This improvement is particularly crucial for our study as we aim to extract very weak polarisation signals, comparable to those detected in Type Ia supernovae. We have also demonstrated the applicability of this method to other classes of supernovae via a preliminary study of the first spectropolarimetry observations of superluminous supernovae.Using this scheme, we have calculated synthetic spectropolarimetry for three multi-dimensional explosion models recently proposed as promising candidates to explain Type Ia supernovae. Our findings highlight the power of spectropolarimetry in testing and discriminating between different scenarios. While all the three models predict light curves and flux spectra that are similar to each others and reproduce those observed in Type Ia supernovae comparably well, polarisation does

  18. Adiabatic density perturbations and matter generation from the minimal supersymmetric standard model.

    Science.gov (United States)

    Enqvist, Kari; Kasuya, Shinta; Mazumdar, Anupam

    2003-03-07

    We propose that the inflaton is coupled to ordinary matter only gravitationally and that it decays into a completely hidden sector. In this scenario both baryonic and dark matter originate from the decay of a flat direction of the minimal supersymmetric standard model, which is shown to generate the desired adiabatic perturbation spectrum via the curvaton mechanism. The requirement that the energy density along the flat direction dominates over the inflaton decay products fixes the flat direction almost uniquely. The present residual energy density in the hidden sector is typically shown to be small.

  19. Narrow-line laser cooling by adiabatic transfer

    Science.gov (United States)

    Norcia, Matthew A.; Cline, Julia R. K.; Bartolotta, John P.; Holland, Murray J.; Thompson, James K.

    2018-02-01

    We propose and demonstrate a novel laser cooling mechanism applicable to particles with narrow-linewidth optical transitions. By sweeping the frequency of counter-propagating laser beams in a sawtooth manner, we cause adiabatic transfer back and forth between the ground state and a long-lived optically excited state. The time-ordering of these adiabatic transfers is determined by Doppler shifts, which ensures that the associated photon recoils are in the opposite direction to the particle’s motion. This ultimately leads to a robust cooling mechanism capable of exerting large forces via a weak transition and with reduced reliance on spontaneous emission. We present a simple intuitive model for the resulting frictional force, and directly demonstrate its efficacy for increasing the total phase-space density of an atomic ensemble. We rely on both simulation and experimental studies using the 7.5 kHz linewidth 1S0 to 3P1 transition in 88Sr. The reduced reliance on spontaneous emission may allow this adiabatic sweep method to be a useful tool for cooling particles that lack closed cycling transitions, such as molecules.

  20. Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave Overpressure Impacts

    Science.gov (United States)

    2017-11-01

    Many TBIs are associated with blast from improvised explosive devices.2–4 Explosions are physical, chemical , or nuclear reactions involving a rapid...ARL-TR-8210 ● NOV 2017 US Army Research Laboratory Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave...Research Laboratory Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave Overpressure Impacts by Nicole E Zander, Thuvan

  1. Improved Overpressure Recording and Modeling for Near-Surface Explosion Forensics

    Science.gov (United States)

    Kim, K.; Schnurr, J.; Garces, M. A.; Rodgers, A. J.

    2017-12-01

    The accurate recording and analysis of air-blast acoustic waveforms is a key component of the forensic analysis of explosive events. Smartphone apps can enhance traditional technologies by providing scalable, cost-effective ubiquitous sensor solutions for monitoring blasts, undeclared activities, and inaccessible facilities. During a series of near-surface chemical high explosive tests, iPhone 6's running the RedVox infrasound recorder app were co-located with high-fidelity Hyperion overpressure sensors, allowing for direct comparison of the resolution and frequency content of the devices. Data from the traditional sensors is used to characterize blast signatures and to determine relative iPhone microphone amplitude and phase responses. A Wiener filter based source deconvolution method is applied, using a parameterized source function estimated from traditional overpressure sensor data, to estimate system responses. In addition, progress on a new parameterized air-blast model is presented. The model is based on the analysis of a large set of overpressure waveforms from several surface explosion test series. An appropriate functional form with parameters determined empirically from modern air-blast and acoustic data will allow for better parameterization of signals and the improved characterization of explosive sources.

  2. Trapped Ion Quantum Computation by Adiabatic Passage

    International Nuclear Information System (INIS)

    Feng Xuni; Wu Chunfeng; Lai, C. H.; Oh, C. H.

    2008-01-01

    We propose a new universal quantum computation scheme for trapped ions in thermal motion via the technique of adiabatic passage, which incorporates the advantages of both the adiabatic passage and the model of trapped ions in thermal motion. Our scheme is immune from the decoherence due to spontaneous emission from excited states as the system in our scheme evolves along a dark state. In our scheme the vibrational degrees of freedom are not required to be cooled to their ground states because they are only virtually excited. It is shown that the fidelity of the resultant gate operation is still high even when the magnitude of the effective Rabi frequency moderately deviates from the desired value.

  3. Explosive synchronization coexists with classical synchronization in the Kuramoto model

    Energy Technology Data Exchange (ETDEWEB)

    Danziger, Michael M., E-mail: michael.danziger@biu.ac.il; Havlin, Shlomo [Department of Physics, Bar-Ilan University, Ramat Gan (Israel); Moskalenko, Olga I.; Kurkin, Semen A. [Faculty of Nonlinear Processes, Saratov State University, Astrakhanskaya, 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politehnicheskaya, 77, Saratov 410054 (Russian Federation); Zhang, Xiyun [Department of Physics, East China Normal University, Shanghai 200062 (China); Boccaletti, Stefano [CNR-Institute of Complex Systems, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy); The Italian Embassy in Israel, 25 Hamered Street, 68125 Tel Aviv (Israel)

    2016-06-15

    Explosive synchronization has recently been reported in a system of adaptively coupled Kuramoto oscillators, without any conditions on the frequency or degree of the nodes. Here, we find that, in fact, the explosive phase coexists with the standard phase of the Kuramoto oscillators. We determine this by extending the mean-field theory of adaptively coupled oscillators with full coupling to the case with partial coupling of a fraction f. This analysis shows that a metastable region exists for all finite values of f > 0, and therefore explosive synchronization is expected for any perturbation of adaptively coupling added to the standard Kuramoto model. We verify this theory with GPU-accelerated simulations on very large networks (N ∼ 10{sup 6}) and find that, in fact, an explosive transition with hysteresis is observed for all finite couplings. By demonstrating that explosive transitions coexist with standard transitions in the limit of f → 0, we show that this behavior is far more likely to occur naturally than was previously believed.

  4. Gasdynamic Model of Turbulent Combustion in TNT Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Bell, J B; Beckner, V E

    2010-01-08

    A model is proposed to simulate turbulent combustion in confined TNT explosions. It is based on: (i) the multi-component gasdynamic conservation laws, (ii) a fast-chemistry model for TNT-air combustion, (iii) a thermodynamic model for frozen reactants and equilibrium products, (iv) a high-order Godunov scheme providing a non-diffusive solution of the governing equations, and (v) an ILES approach whereby adaptive mesh refinement is used to capture the energy bearing scales of the turbulence on the grid. Three-dimensional numerical simulations of explosion fields from 1.5-g PETN/TNT charges were performed. Explosions in six different chambers were studied: three calorimeters (volumes of 6.6-l, 21.2-l and 40.5-l with L/D = 1), and three tunnels (L/D = 3.8, 4.65 and 12.5 with volumes of 6.3-l) - to investigate the influence of chamber volume and geometry on the combustion process. Predicted pressures histories were quite similar to measured pressure histories for all cases studied. Experimentally, mass fraction of products, Y{sub p}{sup exp}, reached a peak value of 88% at an excess air ratio of twice stoichiometric, and then decayed with increasing air dilution; mass fractions Y{sub p}{sup calc} computed from the numerical simulations followed similar trends. Based on this agreement, we conclude that the dominant effect that controls the rate of TNT combustion with air is the turbulent mixing rate; the ILES approach along with the fast-chemistry model used here adequately captures this effect.

  5. Chemistry resolved kinetic flow modeling of TATB based explosives

    Science.gov (United States)

    Vitello, Peter; Fried, Laurence E.; William, Howard; Levesque, George; Souers, P. Clark

    2012-03-01

    Detonation waves in insensitive, TATB-based explosives are believed to have multiple time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. We use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. We term our model chemistry resolved kinetic flow, since CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. We present here two variants of our new rate model and comparison with hot, ambient, and cold experimental data for PBX 9502.

  6. MODELING SNR CASSIOPEIA A FROM THE SUPERNOVA EXPLOSION TO ITS CURRENT AGE: THE ROLE OF POST-EXPLOSION ANISOTROPIES OF EJECTA

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F., E-mail: orlando@astropa.inaf.it [INAF—Osservatorio Astronomico di Palermo “G.S. Vaiana,” Piazza del Parlamento 1, I-90134 Palermo (Italy)

    2016-05-01

    The remnants of core-collapse supernovae (SNe) have complex morphologies that may reflect asymmetries and structures developed during the progenitor SN explosion. Here we investigate how the morphology of the supernova remnant Cassiopeia A (Cas A) reflects the characteristics of the progenitor SN with the aim of deriving the energies and masses of the post-explosion anisotropies responsible for the observed spatial distribution of Fe and Si/S. We model the evolution of Cas A from the immediate aftermath of the progenitor SN to the three-dimensional interaction of the remnant with the surrounding medium. The post-explosion structure of the ejecta is described by small-scale clumping of material and larger-scale anisotropies. The hydrodynamic multi-species simulations consider an appropriate post-explosion isotopic composition of the ejecta. The observed average expansion rate and shock velocities can be well reproduced by models with ejecta mass M {sub ej} ≈ 4 M {sub ⊙} and explosion energy E {sub SN} ≈ 2.3 × 10{sup 51} erg. The post-explosion anisotropies (pistons) reproduce the observed distributions of Fe and Si/S if they had a total mass of ≈0.25 M {sub ⊙} and a total kinetic energy of ≈1.5 × 10{sup 50} erg. The pistons produce a spatial inversion of ejecta layers at the epoch of Cas A, leading to the Si/S-rich ejecta physically interior to the Fe-rich ejecta. The pistons are also responsible for the development of the bright rings of Si/S-rich material which form at the intersection between the reverse shock and the material accumulated around the pistons during their propagation. Our result supports the idea that the bulk of asymmetries observed in Cas A are intrinsic to the explosion.

  7. Geometry of the Adiabatic Theorem

    Science.gov (United States)

    Lobo, Augusto Cesar; Ribeiro, Rafael Antunes; Ribeiro, Clyffe de Assis; Dieguez, Pedro Ruas

    2012-01-01

    We present a simple and pedagogical derivation of the quantum adiabatic theorem for two-level systems (a single qubit) based on geometrical structures of quantum mechanics developed by Anandan and Aharonov, among others. We have chosen to use only the minimum geometric structure needed for the understanding of the adiabatic theorem for this case.…

  8. An adiabatic time-dependent Hartree-Fock theory of collective motion in finite systems

    International Nuclear Information System (INIS)

    Baranger, M.; Veneroni, M.

    1977-11-01

    It is shown how to derive the parameters of a phenomenological collective model from a microscopic theory. The microscopic theory is Hartree-Fock, and one starts from the time-dependent Hartree-Fock equation. To this, the adiabatic approximation is added, and the energy in powers of an adiabatic parameter is expanded, which results in a collective kinetic energy quadratic in the velocities, with coefficients depending on the coordinates, as in the phenomenological models. The adiabatic equations of motion are derived in different ways and their analogy with classical mechanics is stressed. The role of the adiabatic hypothesis and its range of validity, are analyzed in detail. It assumes slow motion, but not small amplitude, and is therefore suitable for large-amplitude collective motion. The RPA is obtained as the limiting case where the amplitude is also small. The translational mass is correctly given and the moment of inertia under rotation is that of Thouless and Valatin

  9. Quantum adiabatic Markovian master equations

    International Nuclear Information System (INIS)

    Albash, Tameem; Zanardi, Paolo; Boixo, Sergio; Lidar, Daniel A

    2012-01-01

    We develop from first principles Markovian master equations suited for studying the time evolution of a system evolving adiabatically while coupled weakly to a thermal bath. We derive two sets of equations in the adiabatic limit, one using the rotating wave (secular) approximation that results in a master equation in Lindblad form, the other without the rotating wave approximation but not in Lindblad form. The two equations make markedly different predictions depending on whether or not the Lamb shift is included. Our analysis keeps track of the various time and energy scales associated with the various approximations we make, and thus allows for a systematic inclusion of higher order corrections, in particular beyond the adiabatic limit. We use our formalism to study the evolution of an Ising spin chain in a transverse field and coupled to a thermal bosonic bath, for which we identify four distinct evolution phases. While we do not expect this to be a generic feature, in one of these phases dissipation acts to increase the fidelity of the system state relative to the adiabatic ground state. (paper)

  10. Physical-chemical model of nanodiamond formation at explosion

    International Nuclear Information System (INIS)

    Chernyshev, A.P.; Lukyanchikov, L.A.; Lyakhov, N.Z.; Pruuel, E.R.; Sheromov, M.A.; Ten, K.A.; Titov, V.M.; Tolochko, B.P.; Zhogin, I.L.; Zubkov, P.I.

    2007-01-01

    This article presents a principally new physical-chemical model of nanodiamond formation at explosion, which describes adequately all the existing experimental data on detonation synthesis of diamonds. According to this model, the detonation wave (DW) performs activation rapidly; then the reaction mixture composition keeps varying. In the diagram C-H-O, this process results in continual motion of the point imaging the reaction mixture composition. The ratio of the diamond phase amount to the condensed carbon (CC) quantity in the explosion products is defined by the width of the section this point passes over in the diamond formation zone. Motion of the point in the area below the line H-CO results in decrease of the CC amount. Diamonds are formed by the free-radical mechanism in the unloading wave, beyond the Chapman-Jouguet plane, in a media close to a liquid state

  11. Physical-chemical model of nanodiamond formation at explosion

    Energy Technology Data Exchange (ETDEWEB)

    Chernyshev, A.P. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, ul. Kutateladze 18, Novosibirsk 630128 (Russian Federation); Novosibirsk State Technical University, Novosibirsk 630092 (Russian Federation); Lukyanchikov, L.A. [Lavrentiev Institute of Hydrodynamics, Novosibirsk 630090 (Russian Federation); Lyakhov, N.Z. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, ul. Kutateladze 18, Novosibirsk 630128 (Russian Federation); Pruuel, E.R. [Lavrentiev Institute of Hydrodynamics, Novosibirsk 630090 (Russian Federation); Sheromov, M.A. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation); Ten, K.A. [Lavrentiev Institute of Hydrodynamics, Novosibirsk 630090 (Russian Federation); Titov, V.M. [Lavrentiev Institute of Hydrodynamics, Novosibirsk 630090 (Russian Federation); Tolochko, B.P. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, ul. Kutateladze 18, Novosibirsk 630128 (Russian Federation)]. E-mail: b.p.tolochko@inp.nsk.su; Zhogin, I.L. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, ul. Kutateladze 18, Novosibirsk 630128 (Russian Federation); Zubkov, P.I. [Lavrentiev Institute of Hydrodynamics, Novosibirsk 630090 (Russian Federation)

    2007-05-21

    This article presents a principally new physical-chemical model of nanodiamond formation at explosion, which describes adequately all the existing experimental data on detonation synthesis of diamonds. According to this model, the detonation wave (DW) performs activation rapidly; then the reaction mixture composition keeps varying. In the diagram C-H-O, this process results in continual motion of the point imaging the reaction mixture composition. The ratio of the diamond phase amount to the condensed carbon (CC) quantity in the explosion products is defined by the width of the section this point passes over in the diamond formation zone. Motion of the point in the area below the line H-CO results in decrease of the CC amount. Diamonds are formed by the free-radical mechanism in the unloading wave, beyond the Chapman-Jouguet plane, in a media close to a liquid state.

  12. Modeling a High Explosive Cylinder Experiment

    Science.gov (United States)

    Zocher, Marvin A.

    2017-06-01

    Cylindrical assemblies constructed from high explosives encased in an inert confining material are often used in experiments aimed at calibrating and validating continuum level models for the so-called equation of state (constitutive model for the spherical part of the Cauchy tensor). Such is the case in the work to be discussed here. In particular, work will be described involving the modeling of a series of experiments involving PBX-9501 encased in a copper cylinder. The objective of the work is to test and perhaps refine a set of phenomenological parameters for the Wescott-Stewart-Davis reactive burn model. The focus of this talk will be on modeling the experiments, which turned out to be non-trivial. The modeling is conducted using ALE methodology.

  13. FRW-type cosmologies with adiabatic matter creation

    International Nuclear Information System (INIS)

    Lima, J.A.; Germano, A.S.; Abramo, L.R.

    1996-01-01

    Some properties of cosmological models with matter creation are investigated in the framework of the Friedmann-Robertson-Walker line element. For adiabatic matter creation, as developed by Prigogine and co-workers, we derive a simple expression relating the particle number density n and energy density ρ which holds regardless of the matter creation rate. The conditions to generate inflation are discussed and by considering the natural phenomenological matter creation rate ψ=3βnH, where β is a pure number of the order of unity and H is the Hubble parameter, a minimally modified hot big-bang model is proposed. The dynamic properties of such models can be deduced from the standard ones simply by replacing the adiabatic index γ of the equation of state by an effective parameter γ * =γ(1-β). The thermodynamic behavior is determined and it is also shown that ages large enough to agree with observations are obtained even given the high values of H suggested by recent measurements. copyright 1996 The American Physical Society

  14. TRACER-II: a complete computational model for mixing and propagation of vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K.H. [School of Mechanical Engineering, Korea Maritime Univ., Pusan (Korea, Republic of); Park, I.G.; Park, G.C.

    1998-01-01

    A vapor explosion is a physical process in which very rapid energy transfer occurs between a hot liquid and a volatile, colder liquid when the two liquids come into a sudden contact. For the analyses of potential impacts from such explosive events, a computer program, TRACER-II, has been developed, which contains a complete description of mixing and propagation phases of vapor explosions. The model consists of fuel, fragmented fuel (debris), coolant liquid, and coolant vapor in two-dimensional Eulerian coordinates. The set of governing equations are solved numerically using finite difference method. The results of this numerical simulation of vapor explosions are discussed in comparison with the recent experimental data of FARO and KROTOS tests. When compared to some selected FARO and KROTOS data, the fuel-coolant mixing and explosion propagation behavior agree reasonably with the data, although the results are yet sensitive primarily to the melt breakup and fragmentation modeling. (author)

  15. Adiabatic perturbations in pre-big bang models: Matching conditions and scale invariance

    International Nuclear Information System (INIS)

    Durrer, Ruth; Vernizzi, Filippo

    2002-01-01

    At low energy, the four-dimensional effective action of the ekpyrotic model of the universe is equivalent to a slightly modified version of the pre-big bang model. We discuss cosmological perturbations in these models. In particular we address the issue of matching the perturbations from a collapsing to an expanding phase. We show that, under certain physically motivated and quite generic assumptions on the high energy corrections, one obtains n=0 for the spectrum of scalar perturbations in the original pre-big bang model (with a vanishing potential). With the same assumptions, when an exponential potential for the dilaton is included, a scale invariant spectrum (n=1) of adiabatic scalar perturbations is produced under very generic matching conditions, both in a modified pre-big bang and ekpyrotic scenario. We also derive the resulting spectrum for arbitrary power law scale factors matched to a radiation-dominated era

  16. Adiabatic evolution of decoherence-free subspaces and its shortcuts

    Science.gov (United States)

    Wu, S. L.; Huang, X. L.; Li, H.; Yi, X. X.

    2017-10-01

    The adiabatic theorem and shortcuts to adiabaticity for time-dependent open quantum systems are explored in this paper. Starting from the definition of dynamical stable decoherence-free subspace, we show that, under a compact adiabatic condition, the quantum state remains in the time-dependent decoherence-free subspace with an extremely high purity, even though the dynamics of the open quantum system may not be adiabatic. The adiabatic condition mentioned here in the adiabatic theorem for open systems is very similar to that for closed quantum systems, except that the operators required to change slowly are the Lindblad operators. We also show that the adiabatic evolution of decoherence-free subspaces depends on the existence of instantaneous decoherence-free subspaces, which requires that the Hamiltonian of open quantum systems be engineered according to the incoherent control protocol. In addition, shortcuts to adiabaticity for adiabatic decoherence-free subspaces are also presented based on the transitionless quantum driving method. Finally, we provide an example that consists of a two-level system coupled to a broadband squeezed vacuum field to show our theory. Our approach employs Markovian master equations and the theory can apply to finite-dimensional quantum open systems.

  17. A single sphere film boiling model for trigger ability and explosion potential

    International Nuclear Information System (INIS)

    Park, Ik Kyu; Kim, Jong Hwan; Hong, Seong Ho; Hong, Seong Wan

    2012-01-01

    using a single particle film boiling model, and this model was then adapted to various sized particles to evaluate the trigger ability and explosion potential more realistically

  18. Reflections about the modelling of unconfined explosions of air-hydrocarbon mixtures

    International Nuclear Information System (INIS)

    Hendrickx, S.; Lannoy, A.

    1983-01-01

    To design nuclear power plants structures, an evaluation of hazards which can be induced by the industrial activities is needed. These hazards namely involve explosions of flamable air-hydrocarbon gas clouds. Such clouds can drift before ignition, and, when ignited, the generated pressure wave can cause serious damage, even far from the initial accident location. When the designs an industrial plant, the designer has to predict the overpressures capable of jeopardizing the safety functions of the plant. The analysis of real accidental explosions which have actually occurred, on the basis of a total explosion yield and the TNT equivalency concept, is a first step. Indeed, it allows a total explosion yield to be calculated, an empirical TNT equivalent of hydrocarbon to be deducted. Unfortunately, this TNT equivalency concept is scientifically not satisfying. The modelling of an unconfined air-hydrocarbon detonation can be used for safety analysis, if we assume that an unconfined explosion can be a detonation, which is unlikely. (orig./WL)

  19. Adiabatic Quantum Optimization for Associative Memory Recall

    Science.gov (United States)

    Seddiqi, Hadayat; Humble, Travis

    2014-12-01

    Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO). Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are stored in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.

  20. Adiabatic Quantum Optimization for Associative Memory Recall

    Directory of Open Access Journals (Sweden)

    Hadayat eSeddiqi

    2014-12-01

    Full Text Available Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO. Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are stored in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.

  1. Adiabatic theory of ionization of atoms by intense laser pulses

    International Nuclear Information System (INIS)

    Tolstikhin, Oleg I; Morishita, Toru; Watanabe, Shinichi

    2009-01-01

    As a first step towards the adiabatic theory of ionization of atoms by intense laser pulses, here we consider the simplest one-dimensional zero-range potential model. The asymptotic solution to the time-dependent Schroedinger equation in the adiabatic regime is obtained and the photoelectron spectrum is calculated. The factorization formula for the photoelectron spectrum in the back-rescattering region, first suggested by Morishita et al. [Phys. Rev. Lett. 100, 013903 (2008)] on the basis of ab initio calculations, is derived analytically.

  2. On the adiabatic theorem when eigenvalues dive into the continuum

    DEFF Research Database (Denmark)

    Cornean, Decebal Horia; Jensen, Arne; Knörr, Hans Konrad

    2018-01-01

    We consider a reduced two-channel model of an atom consisting of a quantum dot coupled to an open scattering channel described by a three-dimensional Laplacian. We are interested in the survival probability of a bound state when the dot energy varies smoothly and adiabatically in time. The initial...... in the adiabatic limit. At the end of the paper, we present a short outlook on how our method may be extended to cover other classes of Hamiltonians; details will be given elsewhere....

  3. Symmetry of the Adiabatic Condition in the Piston Problem

    Science.gov (United States)

    Anacleto, Joaquim; Ferreira, J. M.

    2011-01-01

    This study addresses a controversial issue in the adiabatic piston problem, namely that of the piston being adiabatic when it is fixed but no longer so when it can move freely. It is shown that this apparent contradiction arises from the usual definition of adiabatic condition. The issue is addressed here by requiring the adiabatic condition to be…

  4. Steam explosion studies review

    International Nuclear Information System (INIS)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  5. Deep proton tunneling in the electronically adiabatic and non-adiabatic limits: Comparison of the quantum and classical treatment of donor-acceptor motion in a protein environment

    Energy Technology Data Exchange (ETDEWEB)

    Benabbas, Abdelkrim; Salna, Bridget; Sage, J. Timothy; Champion, Paul M., E-mail: champ@neu.edu [Department of Physics and Center for Interdisciplinary Research on Complex Systems,Northeastern University, Boston, Massachusetts 02115 (United States)

    2015-03-21

    Analytical models describing the temperature dependence of the deep tunneling rate, useful for proton, hydrogen, or hydride transfer in proteins, are developed and compared. Electronically adiabatic and non-adiabatic expressions are presented where the donor-acceptor (D-A) motion is treated either as a quantized vibration or as a classical “gating” distribution. We stress the importance of fitting experimental data on an absolute scale in the electronically adiabatic limit, which normally applies to these reactions, and find that vibrationally enhanced deep tunneling takes place on sub-ns timescales at room temperature for typical H-bonding distances. As noted previously, a small room temperature kinetic isotope effect (KIE) does not eliminate deep tunneling as a major transport channel. The quantum approach focuses on the vibrational sub-space composed of the D-A and hydrogen atom motions, where hydrogen bonding and protein restoring forces quantize the D-A vibration. A Duschinsky rotation is mandated between the normal modes of the reactant and product states and the rotation angle depends on the tunneling particle mass. This tunnel-mass dependent rotation contributes substantially to the KIE and its temperature dependence. The effect of the Duschinsky rotation is solved exactly to find the rate in the electronically non-adiabatic limit and compared to the Born-Oppenheimer (B-O) approximation approach. The B-O approximation is employed to find the rate in the electronically adiabatic limit, where we explore both harmonic and quartic double-well potentials for the hydrogen atom bound states. Both the electronically adiabatic and non-adiabatic rates are found to diverge at high temperature unless the proton coupling includes the often neglected quadratic term in the D-A displacement from equilibrium. A new expression is presented for the electronically adiabatic tunnel rate in the classical limit for D-A motion that should be useful to experimentalists working

  6. Adiabatic translation factors in slow ion-atom collisions

    International Nuclear Information System (INIS)

    Vaaben, J.; Taulbjerg, K.

    1981-01-01

    The general properties of translation factors in slow atomic collisions are discussed. It is emphasised that an acceptable form of translation factors must be conceptually consistent with the basic underlying assumption of the molecular model; i.e. translation factors must relax adiabatically at intermediate and small internuclear separations. A simple physical argument is applied to derive a general parameter-free expression for the translation factor pertinent to an electron in a two-centre Coulomb field. Within the present approach the adiabatic translation factor is considered to be a property of the two-centre field independently of the molecular state under consideration. The generalisation to many-electron systems is therefore readily made. (author)

  7. Accuracy versus run time in an adiabatic quantum search

    International Nuclear Information System (INIS)

    Rezakhani, A. T.; Pimachev, A. K.; Lidar, D. A.

    2010-01-01

    Adiabatic quantum algorithms are characterized by their run time and accuracy. The relation between the two is essential for quantifying adiabatic algorithmic performance yet is often poorly understood. We study the dynamics of a continuous time, adiabatic quantum search algorithm and find rigorous results relating the accuracy and the run time. Proceeding with estimates, we show that under fairly general circumstances the adiabatic algorithmic error exhibits a behavior with two discernible regimes: The error decreases exponentially for short times and then decreases polynomially for longer times. We show that the well-known quadratic speedup over classical search is associated only with the exponential error regime. We illustrate the results through examples of evolution paths derived by minimization of the adiabatic error. We also discuss specific strategies for controlling the adiabatic error and run time.

  8. Unconfined deflagrative explosions without turbulence: experiments and model

    International Nuclear Information System (INIS)

    Lannoy, A.

    1989-01-01

    This paper reviews laboratory, balloon and open field experiments which have been performed to study the deflagration regime in free air. In a first part, are considered different models available to estimate deflagrative unconfined explosions effects, without turbulence. Then, a description is given of the known performed tests, which indicate the effective scale of various experiments, their operating conditions and the type of measurements carried out. Results are presented and discussed. The influence on the explosion force of different parameters (fuel concentration gradients, flammable mixture shape and size, ignition energy) is estimated. The overall conclusion of this survey is that flammable mixtures drifting over open field and ignited, will burn with low flame speed and consequently will generate very weak pressure effects [fr

  9. Modelling of the processes of heat and mass transfer in adiabatic steam and drop flows

    International Nuclear Information System (INIS)

    Andrizhievskij, A.A.; Mikhalevich, A.A.; Nesterenko, V.B.; Trifonov, A.G.

    1983-01-01

    The mathematical models for investigating the local and integral characteristics of heat and mass transfer processes during simultaneous motion of adiabatic steam and drop flow and a flux of impurity particles are given. The mathematical model is constrUcted on the basis of one-dimensional stationary eqUations of conservation of mass, thermal energy and momentum of liquid and vapor phases. Dispersion composition of condensed moisture is described by the Nukiyama-Tanasava distribution function formed taking into account the Veber number critical value. Equations of motion and mass balance conservation for impurity particles are included into the mathematical model. These equations are considered as additional inactive phase

  10. Spatial non-adiabatic passage using geometric phases

    Energy Technology Data Exchange (ETDEWEB)

    Benseny, Albert; Busch, Thomas [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Kiely, Anthony; Ruschhaupt, Andreas [University College Cork, Department of Physics, Cork (Ireland); Zhang, Yongping [Okinawa Institute of Science and Technology Graduate University, Quantum Systems Unit, Okinawa (Japan); Shanghai University, Department of Physics, Shanghai (China)

    2017-12-15

    Quantum technologies based on adiabatic techniques can be highly effective, but often at the cost of being very slow. Here we introduce a set of experimentally realistic, non-adiabatic protocols for spatial state preparation, which yield the same fidelity as their adiabatic counterparts, but on fast timescales. In particular, we consider a charged particle in a system of three tunnel-coupled quantum wells, where the presence of a magnetic field can induce a geometric phase during the tunnelling processes. We show that this leads to the appearance of complex tunnelling amplitudes and allows for the implementation of spatial non-adiabatic passage. We demonstrate the ability of such a system to transport a particle between two different wells and to generate a delocalised superposition between the three traps with high fidelity in short times. (orig.)

  11. Fast-forward of quantum adiabatic dynamics in electro-magnetic field

    OpenAIRE

    Masuda, Shumpei; Nakamura, Katsuhiro

    2010-01-01

    We show a method to accelerate quantum adiabatic dynamics of wavefunctions under electro-magnetic field by developing the previous theory (Masuda & Nakamura 2008 and 2010). Firstly we investigate the orbital dynamics of a charged particle. We derive the driving field which accelerates quantum adiabatic dynamics in order to obtain the final adiabatic states except for the spatially uniform phase such as the adiabatic phase in any desired short time. Fast-forward of adiabatic squeezing and tran...

  12. Modeling and simulation of explosion effectiveness as a function of blast and crowd characteristics

    Science.gov (United States)

    Usmani, Zeeshan-Ul-Hassan

    Suicide bombing has become one of the most lethal and favorite modus operandi of terrorist organizations around the world. On average, there is a suicide bombing attack every six days somewhere in the world. While various attempts have been made to assess the impact of explosions on structures and military personnel, little has been done on modeling the impact of a blast wave on a crowd in civilian settings. The assessment of an explosion's effect on a crowd can lead to better management of disasters, triage of patients, locating blast victims under the debris, development of protective gear, and safe distance recommendations to reduce the casualties. The overall goal of this work is to predict the magnitude of injuries and lethality on humans from a blast-wave with various explosive and crowd characteristics, and to compare, contrast, and analyze the performance of explosive and injury models against the real-life data of suicide bombing incidents. This thesis introduces BlastSim---a physics based stationary multi-agent simulation platform to model and simulate a suicide bombing event. The agents are constrained by the physical characteristics and mechanics of the blast wave. The BlastSim is programmed to test, analyze, and validate the results of different model combinations under various conditions with different sets of parameters, such as the crowd and explosive characteristics, blockage and human shields, fragmentation and the bomber's position, in 2-dimensional and 3-dimensional environments. The suicide bombing event can be re-created for forensic analysis. The proposed model combinations show a significant performance---the Harold Brode explosive model with Catherine Lee injury model using the blockage stands out consistently to be the best with an overall cumulative accuracy of 87.6%. When comparing against actual data, overall, prediction accuracy can be increased by 71% using this model combination. The J. Clutter with Reflection explosive model using

  13. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

    1997-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  14. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R [VTT Energy, Espoo (Finland). Energy Systems

    1998-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  15. Escalation scenarios initiated by gas explosions on offshore installations. Probabilistic cause and consequence modelling

    Energy Technology Data Exchange (ETDEWEB)

    Eknes, Monika Loeland

    1996-12-31

    This Dr. ing. thesis deals with escalation scenarios initiated by gas explosions on offshore installations. Gas explosions is one of the major hazards to such installations. The objectives were to estimate the probability of ignition and frequency of gas explosions for gas leaks on top sides of offshore installations, and to estimate the response and resistance of components that could result in escalation if they failed. Main fields considered cover risk analysis methodology, gas explosions, simplified escalation models, evaluation of structural consequences, case studies, and guidelines. 107 refs., 33 figs., 33 tabs.

  16. A Phase Matching, Adiabatic Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lemery, Francois [Hamburg U.; Flöttmann, Klaus [DESY; Kärtner, Franz [CFEL, Hamburg; Piot, Philippe [Northern Illinois U.

    2017-05-01

    Tabletop accelerators are a thing of the future. Reducing their size will require scaling down electromagnetic wavelengths; however, without correspondingly high field gradients, particles will be more susceptible to phase-slippage – especially at low energy. We investigate how an adiabatically-tapered dielectric-lined waveguide could maintain phase-matching between the accelerating mode and electron bunch. We benchmark our simple model with CST and implement it into ASTRA; finally we provide a first glimpse into the beam dynamics in a phase-matching accelerator.

  17. Adiabatic process reversibility: microscopic and macroscopic views

    International Nuclear Information System (INIS)

    Anacleto, Joaquim; Pereira, Mario G

    2009-01-01

    The reversibility of adiabatic processes was recently addressed by two publications. In the first (Miranda 2008 Eur. J. Phys. 29 937-43), an equation was derived relating the initial and final volumes and temperatures for adiabatic expansions of an ideal gas, using a microscopic approach. In that relation the parameter r accounts for the process reversibility, ranging between 0 and 1, which corresponds to the free and reversible expansion, respectively. In the second (Anacleto and Pereira 2009 Eur. J. Phys. 30 177-83), the authors have shown that thermodynamics can effectively and efficiently be used to obtain the general law for adiabatic processes carried out by an ideal gas, including compressions, for which r≥1. The present work integrates and extends the aforementioned studies, providing thus further insights into the analysis of the adiabatic process. It is shown that Miranda's work is wholly valid for compressions. In addition, it is demonstrated that the adiabatic reversibility coefficient given in terms of the piston velocity and the root mean square velocity of the gas particles is equivalent to the macroscopic description, given just by the quotient between surroundings and system pressure values. (letters and comments)

  18. Specific absorption rate determination of magnetic nanoparticles through hyperthermia measurements in non-adiabatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Coïsson, M. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Barrera, G. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); University of Torino, Chemistry Department, via P. Giuria 7, 10125 Torino (Italy); Celegato, F.; Martino, L.; Vinai, F. [INRIM, strada delle Cacce 91, 10135 Torino (Italy); Martino, P. [Politronica srl, via Livorno 60, 10144 Torino (Italy); Ferraro, G. [Center for Space Human Robotics, Istituto Italiano di Tecnologia - IIT, corso Trento 21, 10129 Torino (Italy); Tiberto, P. [INRIM, strada delle Cacce 91, 10135 Torino (Italy)

    2016-10-01

    An experimental setup for magnetic hyperthermia operating in non-adiabatic conditions is described. A thermodynamic model that takes into account the heat exchanged by the sample with the surrounding environment is developed. A suitable calibration procedure is proposed that allows the experimental validation of the model. Specific absorption rate can then be accurately determined just from the measurement of the sample temperature at the equilibrium steady state. The setup and the measurement procedure represent a simplification with respect to other systems requiring calorimeters or crucial corrections for heat flow. Two families of magnetic nanoparticles, one superparamagnetic and one characterised by larger sizes and static hysteresis, have been characterised as a function of field intensity, and specific absorption rate and intrinsic loss power have been obtained. - Highlights: • Development and thermodynamic modelling of a hyperthermia setup operating in non-adiabatic conditions. • Calibration of the experimental setup and validation of the model. • Accurate measurement of specific absorption rate and intrinsic loss power in non-adiabatic conditions.

  19. Optimization using quantum mechanics: quantum annealing through adiabatic evolution

    International Nuclear Information System (INIS)

    Santoro, Giuseppe E; Tosatti, Erio

    2006-01-01

    We review here some recent work in the field of quantum annealing, alias adiabatic quantum computation. The idea of quantum annealing is to perform optimization by a quantum adiabatic evolution which tracks the ground state of a suitable time-dependent Hamiltonian, where 'ℎ' is slowly switched off. We illustrate several applications of quantum annealing strategies, starting from textbook toy-models-double-well potentials and other one-dimensional examples, with and without disorder. These examples display in a clear way the crucial differences between classical and quantum annealing. We then discuss applications of quantum annealing to challenging hard optimization problems, such as the random Ising model, the travelling salesman problem and Boolean satisfiability problems. The techniques used to implement quantum annealing are either deterministic Schroedinger's evolutions, for the toy models, or path-integral Monte Carlo and Green's function Monte Carlo approaches, for the hard optimization problems. The crucial role played by disorder and the associated non-trivial Landau-Zener tunnelling phenomena is discussed and emphasized. (topical review)

  20. On the recirculation of ammonia-lithium nitrate in adiabatic absorbers for chillers

    International Nuclear Information System (INIS)

    Ventas, R.; Lecuona, A.; Legrand, M.; Rodriguez-Hidalgo, M.C.

    2010-01-01

    This paper presents a numerical model of single-effect absorption cycles with ammonia-lithium nitrate solution as the working pair and incorporating an adiabatic absorber. It is based on UA-ΔT lm models for separate regions of plate-type heat exchangers and it assumes an approach factor to adiabatic equilibrium. The results are offered as a function of external temperatures. A loop circuit with a heat exchanger upstream the absorber produces subcooling for facilitating absorption process. The effect of the mass flow rate recirculated through the absorber is studied. Results show a diminishing return effect. The value at which the recirculation mass flow yields a reasonable performance is between 4 and 6 times the solution mass flow. With a heat transfer area 6 times smaller than with a conventional diabatic shell-and-tube type absorber, the adiabatic absorber configured with a plate heat exchanger yields a 2% smaller maximum COP and a 15-20% smaller cooling power.

  1. Quantum entangling power of adiabatically connected Hamiltonians

    International Nuclear Information System (INIS)

    Hamma, Alioscia; Zanardi, Paolo

    2004-01-01

    The space of quantum Hamiltonians has a natural partition in classes of operators that can be adiabatically deformed into each other. We consider parametric families of Hamiltonians acting on a bipartite quantum state space. When the different Hamiltonians in the family fall in the same adiabatic class, one can manipulate entanglement by moving through energy eigenstates corresponding to different values of the control parameters. We introduce an associated notion of adiabatic entangling power. This novel measure is analyzed for general dxd quantum systems, and specific two-qubit examples are studied

  2. Adiabatic logic future trend and system level perspective

    CERN Document Server

    Teichmann, Philip

    2012-01-01

    Adiabatic logic is a potential successor for static CMOS circuit design when it comes to ultra-low-power energy consumption. Future development like the evolutionary shrinking of the minimum feature size as well as revolutionary novel transistor concepts will change the gate level savings gained by adiabatic logic. In addition, the impact of worsening degradation effects has to be considered in the design of adiabatic circuits. The impact of the technology trends on the figures of merit of adiabatic logic, energy saving potential and optimum operating frequency, are investigated, as well as degradation related issues. Adiabatic logic benefits from future devices, is not susceptible to Hot Carrier Injection, and shows less impact of Bias Temperature Instability than static CMOS circuits. Major interest also lies on the efficient generation of the applied power-clock signal. This oscillating power supply can be used to save energy in short idle times by disconnecting circuits. An efficient way to generate the p...

  3. Perturbation to Unified Symmetry and Adiabatic Invariants for Relativistic Hamilton Systems

    International Nuclear Information System (INIS)

    Zhang Mingjiang; Fang Jianhui; Lu Kai; Pang Ting; Lin Peng

    2009-01-01

    Based on the concept of adiabatic invariant, the perturbation to unified symmetry and adiabatic invariants for relativistic Hamilton systems are studied. The definition of the perturbation to unified symmetry for the system is presented, and the criterion of the perturbation to unified symmetry is given. Meanwhile, the Noether adiabatic invariants, the generalized Hojman adiabatic invariants, and the Mei adiabatic invariants for the perturbed system are obtained. (general)

  4. Modeling of tamped and decoupled explosions in salt (simulation is easy. Prediction is difficult exclamation point)

    International Nuclear Information System (INIS)

    Goldstein, P.; Glenn, L.A.

    1993-01-01

    We compare predictions of the strain hardening model of Glenn (1990), with and without damage, to free field and seismic observations of SALMON, STERLING, and 64 kt (tamped) and 8 kt (decoupled) explosions in an Azgir salt dome in the former Soviet Union (FSU). We find good agreement between the model (without damage) and observations of both SALMON and STERLING. In contrast, the average spectral ratio of the tamped to decoupled Azgir explosions is systematically smaller than predicted by the strain hardening model without damage. Much better agreement is obtained when damage is included in the model of the decoupled Azgir explosion

  5. Modeling of tamped and decoupled explosions in salt (Simulation is easy. Prediction is difficult exclamation point)

    International Nuclear Information System (INIS)

    Goldstein, P.; Glenn, L.A.

    1993-05-01

    We compare predictions of the strain hardening model of Glenn (1990), with and without damage, to free field and seismic observations of SALMON, STERLING, and 64 kt (tamped) and 8 kt (decoupled) explosions in an Azgir salt dome in the former Soviet Union (FSU). We find good agreement between the model (without damage) and observations of both SALMON and STERLING. In contrast, the average spectral ratio of the tamped to decoupled Azgir explosions is systematically smaller than predicted by the strain hardening model without damage. Much better agreement is obtained when damage is included in the model of the decoupled Azgir explosion

  6. Non-adiabatic Excited State Molecule Dynamics Modeling of Photochemistry and Photophysics of Materials

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Tammie Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tretiak, Sergei [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-06

    Understanding and controlling excited state dynamics lies at the heart of all our efforts to design photoactive materials with desired functionality. This tailor-design approach has become the standard for many technological applications (e.g., solar energy harvesting) including the design of organic conjugated electronic materials with applications in photovoltaic and light-emitting devices. Over the years, our team has developed efficient LANL-based codes to model the relevant photophysical processes following photoexcitation (spatial energy transfer, excitation localization/delocalization, and/or charge separation). The developed approach allows the non-radiative relaxation to be followed on up to ~10 ps timescales for large realistic molecules (hundreds of atoms in size) in the realistic solvent dielectric environment. The Collective Electronic Oscillator (CEO) code is used to compute electronic excited states, and the Non-adiabatic Excited State Molecular Dynamics (NA-ESMD) code is used to follow the non-adiabatic dynamics on multiple coupled Born-Oppenheimer potential energy surfaces. Our preliminary NA-ESMD simulations have revealed key photoinduced mechanisms controlling competing interactions and relaxation pathways in complex materials, including organic conjugated polymer materials, and have provided a detailed understanding of photochemical products and intermediates and the internal conversion process during the initiation of energetic materials. This project will be using LANL-based CEO and NA-ESMD codes to model nonradiative relaxation in organic and energetic materials. The NA-ESMD and CEO codes belong to a class of electronic structure/quantum chemistry codes that require large memory, “long-queue-few-core” distribution of resources in order to make useful progress. The NA-ESMD simulations are trivially parallelizable requiring ~300 processors for up to one week runtime to reach a meaningful restart point.

  7. Regional Seismic Amplitude Modeling and Tomography for Earthquake-Explosion Discrimination

    Science.gov (United States)

    Walter, W. R.; Pasyanos, M. E.; Matzel, E.; Gok, R.; Sweeney, J.; Ford, S. R.; Rodgers, A. J.

    2008-12-01

    Empirically explosions have been discriminated from natural earthquakes using regional amplitude ratio techniques such as P/S in a variety of frequency bands. We demonstrate that such ratios discriminate nuclear tests from earthquakes using closely located pairs of earthquakes and explosions recorded on common, publicly available stations at test sites around the world (e.g. Nevada, Novaya Zemlya, Semipalatinsk, Lop Nor, India, Pakistan, and North Korea). We are examining if there is any relationship between the observed P/S and the point source variability revealed by longer period full waveform modeling. For example, regional waveform modeling shows strong tectonic release from the May 1998 India test, in contrast with very little tectonic release in the October 2006 North Korea test, but the P/S discrimination behavior appears similar in both events using the limited regional data available. While regional amplitude ratios such as P/S can separate events in close proximity, it is also empirically well known that path effects can greatly distort observed amplitudes and make earthquakes appear very explosion-like. Previously we have shown that the MDAC (Magnitude Distance Amplitude Correction, Walter and Taylor, 2001) technique can account for simple 1-D attenuation and geometrical spreading corrections, as well as magnitude and site effects. However in some regions 1-D path corrections are a poor approximation and we need to develop 2-D path corrections. Here we demonstrate a new 2-D attenuation tomography technique using the MDAC earthquake source model applied to a set of events and stations in both the Middle East and the Yellow Sea Korean Peninsula regions. We believe this new 2-D MDAC tomography has the potential to greatly improve earthquake-explosion discrimination, particularly in tectonically complex regions such as the Middle East.

  8. Modeling solid thermal explosion containment on reactor HNIW and HMX

    International Nuclear Information System (INIS)

    Lin, Chun-Ping; Chang, Chang-Ping; Chou, Yu-Chuan; Chu, Yung-Chuan; Shu, Chi-Min

    2010-01-01

    2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane (HNIW), also known as CL-20 and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), are highly energetic materials which have been popular in national defense industries for years. This study established the models of thermal decomposition and thermal explosion hazard for HNIW and HMX. Differential scanning calorimetry (DSC) data were used for parameters determination of the thermokinetic models, and then these models were employed for simulation of thermal explosion in a 437 L barrel reactor and a 24 kg cubic box package. Experimental results indicating the best storage conditions to avoid any violent runaway reaction of HNIW and HMX were also discovered. This study also developed an efficient procedure regarding creation of thermokinetics and assessment of thermal hazards of HNIW and HMX that could be applied to ensure safe storage conditions.

  9. Explosive coalescence of magnetic islands and explosive particle acceleration

    International Nuclear Information System (INIS)

    Tajima, T.; Sakai, J.I.

    1985-07-01

    An explosive reconnection process associated with the nonlinear evolution of the coalescence instability is found through studies of the electromagnetic particle simulation and the magnetohydrodynamic particle simulation. The explosive coalescence is a process of magnetic collapse, in which we find the magnetic and electrostatic field energies and temperatures (ion temperature in the coalescing direction, in particular) explode toward the explosion time t 0 as (t 0 - t)/sup -8/3/, (t 0 - t) -4 , and (t 0 - t)/sup -8/3/, respectively for a canonical case. Single-peak, double-peak, and triple-peak structures of magnetic energy, temperature, and electrostatic energy, respectively, are observed on the simulation as overshoot amplitude oscillations and are theoretically explained. The heuristic model of Brunel and Tajima is extended to this explosive coalescence in order to extract the basic process. Since the explosive coalescence exhibits self-similarity, a temporal universality, we theoretically search for a self-similar solution to the two-fluid plasma equations

  10. Modelling of nuclear explosions in hard rock sites

    International Nuclear Information System (INIS)

    Brunish, W.M.; App, F.N.

    1993-01-01

    This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock

  11. Design of ternary clocked adiabatic static random access memory

    International Nuclear Information System (INIS)

    Wang Pengjun; Mei Fengna

    2011-01-01

    Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions. (semiconductor integrated circuits)

  12. Design of ternary clocked adiabatic static random access memory

    Science.gov (United States)

    Pengjun, Wang; Fengna, Mei

    2011-10-01

    Based on multi-valued logic, adiabatic circuits and the structure of ternary static random access memory (SRAM), a design scheme of a novel ternary clocked adiabatic SRAM is presented. The scheme adopts bootstrapped NMOS transistors, and an address decoder, a storage cell and a sense amplifier are charged and discharged in the adiabatic way, so the charges stored in the large switch capacitance of word lines, bit lines and the address decoder can be effectively restored to achieve energy recovery during reading and writing of ternary signals. The PSPICE simulation results indicate that the ternary clocked adiabatic SRAM has a correct logic function and low power consumption. Compared with ternary conventional SRAM, the average power consumption of the ternary adiabatic SRAM saves up to 68% in the same conditions.

  13. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation

    Directory of Open Access Journals (Sweden)

    Barban C.

    2013-03-01

    Full Text Available CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensity-velocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star.

  14. Generation of a scale-invariant spectrum of adiabatic fluctuations in cosmological models with a contracting phase

    International Nuclear Information System (INIS)

    Finelli, Fabio; Brandenberger, Robert

    2002-01-01

    In pre-big-bang and in ekpyrotic cosmology, perturbations on cosmological scales today are generated from quantum vacuum fluctuations during a phase when the Universe is contracting (viewed in the Einstein frame). The backgrounds studied to date do not yield a scale-invariant spectrum of adiabatic fluctuations. Here, we present a new contracting background model (neither of pre-big-bang nor of the ekpyrotic form) involving a single scalar field coupled to gravity in which a scale-invariant spectrum of curvature fluctuations and gravitational waves results. The equation of state of this scalar field corresponds to cold matter. We demonstrate that if this contracting phase can be matched via a nonsingular bounce to an expanding Friedmann cosmology, the scale-invariance of the curvature fluctuations is maintained. We also find new background solutions for pre-big-bang and for ekpyrotic cosmology, which involve two scalar fields with exponential potentials with background values which are evolving in time. We comment on the difficulty of obtaining a scale-invariant spectrum of adiabatic fluctuations with background solutions which have been studied in the past

  15. Modification of optical properties by adiabatic shifting of resonances in a four-level atom

    Science.gov (United States)

    Dutta, Bibhas Kumar; Panchadhyayee, Pradipta

    2018-04-01

    We describe the linear and nonlinear optical properties of a four-level atomic system, after reducing it to an effective two-level atomic model under the condition of adiabatic shifting of resonances driven by two coherent off-resonant fields. The reduced form of the Hamiltonian corresponding to the two-level system is obtained by employing an adiabatic elimination procedure in the rate equations of the probability amplitudes for the proposed four-level model. For a weak probe field operating in the system, the nonlinear dependence of complex susceptibility on the Rabi frequencies and the detuning parameters of the off-resonant driving fields makes it possible to exhibit coherent control of single-photon and two-photon absorption and transparency, the evolution of enhanced Self-Kerr nonlinearity and noticeable dispersive switching. We have shown how the quantum interference results in the generic four-level model at the adiabatic limit. The present scheme describes the appearance of single-photon transparency without invoking any exact two-photon resonance.

  16. REGIONAL SEISMIC AMPLITUDE MODELING AND TOMOGRAPHY FOR EARTHQUAKE-EXPLOSION DISCRIMINATION

    Energy Technology Data Exchange (ETDEWEB)

    Walter, W R; Pasyanos, M E; Matzel, E; Gok, R; Sweeney, J; Ford, S R; Rodgers, A J

    2008-07-08

    We continue exploring methodologies to improve earthquake-explosion discrimination using regional amplitude ratios such as P/S in a variety of frequency bands. Empirically we demonstrate that such ratios separate explosions from earthquakes using closely located pairs of earthquakes and explosions recorded on common, publicly available stations at test sites around the world (e.g. Nevada, Novaya Zemlya, Semipalatinsk, Lop Nor, India, Pakistan, and North Korea). We are also examining if there is any relationship between the observed P/S and the point source variability revealed by longer period full waveform modeling (e. g. Ford et al 2008). For example, regional waveform modeling shows strong tectonic release from the May 1998 India test, in contrast with very little tectonic release in the October 2006 North Korea test, but the P/S discrimination behavior appears similar in both events using the limited regional data available. While regional amplitude ratios such as P/S can separate events in close proximity, it is also empirically well known that path effects can greatly distort observed amplitudes and make earthquakes appear very explosion-like. Previously we have shown that the MDAC (Magnitude Distance Amplitude Correction, Walter and Taylor, 2001) technique can account for simple 1-D attenuation and geometrical spreading corrections, as well as magnitude and site effects. However in some regions 1-D path corrections are a poor approximation and we need to develop 2-D path corrections. Here we demonstrate a new 2-D attenuation tomography technique using the MDAC earthquake source model applied to a set of events and stations in both the Middle East and the Yellow Sea Korean Peninsula regions. We believe this new 2-D MDAC tomography has the potential to greatly improve earthquake-explosion discrimination, particularly in tectonically complex regions such as the Middle East. Monitoring the world for potential nuclear explosions requires characterizing seismic

  17. Correlated adiabatic and isocurvature cosmic microwave background fluctuations in the wake of the results from the wilkinson microwave anisotropy probe.

    Science.gov (United States)

    Väliviita, Jussi; Muhonen, Vesa

    2003-09-26

    In general correlated models, in addition to the usual adiabatic component with a spectral index n(ad1) there is another adiabatic component with a spectral index n(ad2) generated by entropy perturbation during inflation. We extend the analysis of a correlated mixture of adiabatic and isocurvature cosmic microwave background fluctuations of the Wilkinson Microwave Anisotropy Probe (WMAP) group, who set the two adiabatic spectral indices equal. Allowing n(ad1) and n(ad2) to vary independently we find that the WMAP data favor models where the two adiabatic components have opposite spectral tilts. Using the WMAP data only, the 2sigma upper bound for the isocurvature fraction f(iso) of the initial power spectrum at k(0)=0.05 Mpc(-1) increases somewhat, e.g., from 0.76 of n(ad2)=n(ad1) models to 0.84 with a prior n(iso)<1.84 for the isocurvature spectral index.

  18. TOWARD END-TO-END MODELING FOR NUCLEAR EXPLOSION MONITORING: SIMULATION OF UNDERGROUND NUCLEAR EXPLOSIONS AND EARTHQUAKES USING HYDRODYNAMIC AND ANELASTIC SIMULATIONS, HIGH-PERFORMANCE COMPUTING AND THREE-DIMENSIONAL EARTH MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A; Vorobiev, O; Petersson, A; Sjogreen, B

    2009-07-06

    This paper describes new research being performed to improve understanding of seismic waves generated by underground nuclear explosions (UNE) by using full waveform simulation, high-performance computing and three-dimensional (3D) earth models. The goal of this effort is to develop an end-to-end modeling capability to cover the range of wave propagation required for nuclear explosion monitoring (NEM) from the buried nuclear device to the seismic sensor. The goal of this work is to improve understanding of the physical basis and prediction capabilities of seismic observables for NEM including source and path-propagation effects. We are pursuing research along three main thrusts. Firstly, we are modeling the non-linear hydrodynamic response of geologic materials to underground explosions in order to better understand how source emplacement conditions impact the seismic waves that emerge from the source region and are ultimately observed hundreds or thousands of kilometers away. Empirical evidence shows that the amplitudes and frequency content of seismic waves at all distances are strongly impacted by the physical properties of the source region (e.g. density, strength, porosity). To model the near-source shock-wave motions of an UNE, we use GEODYN, an Eulerian Godunov (finite volume) code incorporating thermodynamically consistent non-linear constitutive relations, including cavity formation, yielding, porous compaction, tensile failure, bulking and damage. In order to propagate motions to seismic distances we are developing a one-way coupling method to pass motions to WPP (a Cartesian anelastic finite difference code). Preliminary investigations of UNE's in canonical materials (granite, tuff and alluvium) confirm that emplacement conditions have a strong effect on seismic amplitudes and the generation of shear waves. Specifically, we find that motions from an explosion in high-strength, low-porosity granite have high compressional wave amplitudes and weak

  19. Quantum tunneling, adiabatic invariance and black hole spectroscopy

    Science.gov (United States)

    Li, Guo-Ping; Pu, Jin; Jiang, Qing-Quan; Zu, Xiao-Tao

    2017-05-01

    In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painlevé) of coordinates as well as in different gravity frames, the adiabatic invariant I_adia = \\oint p_i dq_i introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area.

  20. Shortcuts to adiabaticity in cutting a spin chain

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Feng-Hua [Department of Physics, Ocean University of China, Qingdao 266100 (China); School of Computer Engineering, Qingdao Technological University, Qingdao 266033 (China); Wang, Zhao-Ming, E-mail: mingmoon78@126.com [Department of Physics, Ocean University of China, Qingdao 266100 (China); Gu, Yong-Jian, E-mail: yjgu@ouc.edu.cn [Department of Physics, Ocean University of China, Qingdao 266100 (China)

    2017-01-15

    “Shortcuts to adiabaticity” represents a strategy for accelerating a quantum adiabatic process, is useful for preparing or manipulating a quantum state. In this paper, we investigate the adiabaticity in the dynamics of an XY spin chain. During the process of cutting one long chain into two short chains, a “shortcut” can be obtained by applying a sequence of external pulses. The fidelity which measures the adiabaticity can be dramatically enhanced by increasing the pulse strength or pulse duration time. This reliability can be kept for different types of pulses, such as random pulse time interval or random strength. The free choice of the pulse can be explained by the adiabatic representation of the Hamiltonian, and it shows that the control effects are determined by the integral of the control function in the time domain. - Highlights: • “Shortcuts to adiabaticity” is proposed by applying external pulses. • The adiabaticity can be accelerated by increasing pulse strength or duration time. • Control effects are determined by the integral of the control function with respect to time.

  1. Moment distributions of clusters and molecules in the adiabatic rotor model

    Science.gov (United States)

    Ballentine, G. E.; Bertsch, G. F.; Onishi, N.; Yabana, K.

    2008-01-01

    We present a Fortran program to compute the distribution of dipole moments of free particles for use in analyzing molecular beams experiments that measure moments by deflection in an inhomogeneous field. The theory is the same for magnetic and electric dipole moments, and is based on a thermal ensemble of classical particles that are free to rotate and that have moment vectors aligned along a principal axis of rotation. The theory has two parameters, the ratio of the magnetic (or electric) dipole energy to the thermal energy, and the ratio of moments of inertia of the rotor. Program summaryProgram title:AdiabaticRotor Catalogue identifier:ADZO_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZO_v1_0.html Program obtainable from:CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:479 No. of bytes in distributed program, including test data, etc.:4853 Distribution format:tar.gz Programming language:Fortran 90 Computer:Pentium-IV, Macintosh Power PC G4 Operating system:Linux, Mac OS X RAM:600 Kbytes Word size:64 bits Classification:2.3 Nature of problem:The system considered is a thermal ensemble of rotors having a magnetic or electric moment aligned along one of the principal axes. The ensemble is placed in an external field which is turned on adiabatically. The problem is to find the distribution of moments in the presence of the external field. Solution method:There are three adiabatic invariants. The only nontrivial one is the action associated with the polar angle of the rotor axis with respect to external field. It is found by Newton's method. Running time:3 min on a 3 GHz Pentium IV processor.

  2. The Pore Collapse “Hot-Spots” Model Coupled with Brittle Damage for Solid Explosives

    Directory of Open Access Journals (Sweden)

    L. R. Cheng

    2014-01-01

    Full Text Available This paper is devoted to the building of a numerical pore collapse model with “hot-spots” formation for the impacted damage explosives. According to damage mechanical evolution of brittle material, the one-dimensional elastic-viscoplastic collapse model was improved to incorporate the impact damage during the dynamic collapse of pores. The damage of explosives was studied using the statistical crack mechanics (SCRAM. The effects of the heat conduction and the chemical reaction were taken into account in the formation of “hot-spots.” To verify the improved model, numerical simulations were carried out for different pressure states and used to model a multiple-impact experiment. The results show that repeated weak impacts can lead to the collapse of pores and the “hot-spots” may occur due to the accumulation of internal defects accompanied by the softening of explosives.

  3. Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2016-09-01

    Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH 4 )-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with metal oxide lithium-ion cells extracted from intrinsically safe evaluated equipment were mixed, with one cell model igniting the chamber atmosphere while another cell model did not. The two cells models exhibited different internal short circuit behaviors. A lithium iron phosphate (LiFePO 4 ) cell model was tolerant to crush-induced internal short circuits within CH 4 -air, tested under manufacturer recommended charging conditions. Accelerating rate calorimetry tests with similar cells within a nitrogen purged 353-mL chamber produced ignitions that exceeded explosion proof and flameproof enclosure minimum internal pressure design criteria. Ignition pressures within a 20-L chamber with 6.5% CH 4 -air were relatively low, with much larger head space volume and less adiabatic test conditions. The literature indicates that sizeable lithium thionyl chloride (LiSOCl 2 ) primary (non rechargeable) cell ignitions can be especially violent and toxic. Because ignition of an explosive atmosphere is expected within explosion proof or flameproof enclosures, there is a need to consider the potential for an internal explosive atmosphere ignition in combination with a lithium or lithium-ion battery thermal runaway process, and the resulting effects on the enclosure.

  4. Quantum adiabatic approximation and the geometric phase

    International Nuclear Information System (INIS)

    Mostafazadeh, A.

    1997-01-01

    A precise definition of an adiabaticity parameter ν of a time-dependent Hamiltonian is proposed. A variation of the time-dependent perturbation theory is presented which yields a series expansion of the evolution operator U(τ)=summation scr(l) U (scr(l)) (τ) with U (scr(l)) (τ) being at least of the order ν scr(l) . In particular, U (0) (τ) corresponds to the adiabatic approximation and yields Berry close-quote s adiabatic phase. It is shown that this series expansion has nothing to do with the 1/τ expansion of U(τ). It is also shown that the nonadiabatic part of the evolution operator is generated by a transformed Hamiltonian which is off-diagonal in the eigenbasis of the initial Hamiltonian. This suggests the introduction of an adiabatic product expansion for U(τ) which turns out to yield exact expressions for U(τ) for a large number of quantum systems. In particular, a simple application of the adiabatic product expansion is used to show that for the Hamiltonian describing the dynamics of a magnetic dipole in an arbitrarily changing magnetic field, there exists another Hamiltonian with the same eigenvectors for which the Schroedinger equation is exactly solvable. Some related issues concerning geometric phases and their physical significance are also discussed. copyright 1997 The American Physical Society

  5. Experimental simulation of lightning, interacting explosions and astrophysical jets with pulsed lasers

    International Nuclear Information System (INIS)

    Villagran-Muniz, M; Sobral, H; Navarro-Gonzalez, R; Velazquez, P F; Raga, A C

    2003-01-01

    Tabletop laboratory experiments have been used to simulate natural lightning, interacting explosions and astrophysical jets. When a high-energy laser pulse is focused in air, a laser-induced plasma (LIP) is produced, that generates a shock wave and an adiabatic expansion of the gas. In our work we have used LIPs in order to simulate lightning, for the study of chemical reactions relevant to atmospheric science. Several diagnostics have been applied to our LIPs, such as deflectometry, shadowgraphy and interferometry, which yield full spatial information of the process (electron density and temperature, the position of the shock wave fronts and the expansion of the hot gas), with a time resolution that ranges from nanoseconds to milliseconds. A new diagnostic alternative was implemented for shadowgraphy, which uses either continuous lasers or conventional light sources. The experimental results have been reproduced by hydrodynamic codes that we have developed. With astrophysical applications in mind, we have simulated and diagnosed the interaction of two explosions, with the aforementioned techniques. For this purpose, two LIPs are synchronized and diagnosed spatially and temporarily. Also, by producing the LIP in a glass sphere with a nozzle that ejects a shock wave and hot gas, we are able to simulate astrophysical jets. With such experiments, astrophysical models developed by us have been validated, showing excellent agreement between experiments and numerical simulations

  6. Adiabatic graph-state quantum computation

    International Nuclear Information System (INIS)

    Antonio, B; Anders, J; Markham, D

    2014-01-01

    Measurement-based quantum computation (MBQC) and holonomic quantum computation (HQC) are two very different computational methods. The computation in MBQC is driven by adaptive measurements executed in a particular order on a large entangled state. In contrast in HQC the system starts in the ground subspace of a Hamiltonian which is slowly changed such that a transformation occurs within the subspace. Following the approach of Bacon and Flammia, we show that any MBQC on a graph state with generalized flow (gflow) can be converted into an adiabatically driven holonomic computation, which we call adiabatic graph-state quantum computation (AGQC). We then investigate how properties of AGQC relate to the properties of MBQC, such as computational depth. We identify a trade-off that can be made between the number of adiabatic steps in AGQC and the norm of H-dot as well as the degree of H, in analogy to the trade-off between the number of measurements and classical post-processing seen in MBQC. Finally the effects of performing AGQC with orderings that differ from standard MBQC are investigated. (paper)

  7. Plasma heating by adiabatic compression

    International Nuclear Information System (INIS)

    Ellis, R.A. Jr.

    1972-01-01

    These two lectures will cover the following three topics: (i) The application of adiabatic compression to toroidal devices is reviewed. The special case of adiabatic compression in tokamaks is considered in more detail, including a discussion of the equilibrium, scaling laws, and heating effects. (ii) The ATC (Adiabatic Toroidal Compressor) device which was completed in May 1972, is described in detail. Compression of a tokamak plasma across a static toroidal field is studied in this device. The device is designed to produce a pre-compression plasma with a major radius of 17 cm, toroidal field of 20 kG, and current of 90 kA. The compression leads to a plasma with major radius of 38 cm and minor radius of 10 cm. Scaling laws imply a density increase of a factor 6, temperature increase of a factor 3, and current increase of a factor 2.4. An additional feature of ATC is that it is a large tokamak which operates without a copper shell. (iii) Data which show that the expected MHD behavior is largely observed is presented and discussed. (U.S.)

  8. Path integral density matrix dynamics: a method for calculating time-dependent properties in thermal adiabatic and non-adiabatic systems.

    Science.gov (United States)

    Habershon, Scott

    2013-09-14

    We introduce a new approach for calculating quantum time-correlation functions and time-dependent expectation values in many-body thermal systems; both electronically adiabatic and non-adiabatic cases can be treated. Our approach uses a path integral simulation to sample an initial thermal density matrix; subsequent evolution of this density matrix is equivalent to solution of the time-dependent Schrödinger equation, which we perform using a linear expansion of Gaussian wavepacket basis functions which evolve according to simple classical-like trajectories. Overall, this methodology represents a formally exact approach for calculating time-dependent quantum properties; by introducing approximations into both the imaginary-time and real-time propagations, this approach can be adapted for complex many-particle systems interacting through arbitrary potentials. We demonstrate this method for the spin Boson model, where we find good agreement with numerically exact calculations. We also discuss future directions of improvement for our approach with a view to improving accuracy and efficiency.

  9. Path integral density matrix dynamics: A method for calculating time-dependent properties in thermal adiabatic and non-adiabatic systems

    International Nuclear Information System (INIS)

    Habershon, Scott

    2013-01-01

    We introduce a new approach for calculating quantum time-correlation functions and time-dependent expectation values in many-body thermal systems; both electronically adiabatic and non-adiabatic cases can be treated. Our approach uses a path integral simulation to sample an initial thermal density matrix; subsequent evolution of this density matrix is equivalent to solution of the time-dependent Schrödinger equation, which we perform using a linear expansion of Gaussian wavepacket basis functions which evolve according to simple classical-like trajectories. Overall, this methodology represents a formally exact approach for calculating time-dependent quantum properties; by introducing approximations into both the imaginary-time and real-time propagations, this approach can be adapted for complex many-particle systems interacting through arbitrary potentials. We demonstrate this method for the spin Boson model, where we find good agreement with numerically exact calculations. We also discuss future directions of improvement for our approach with a view to improving accuracy and efficiency

  10. A two-phase model for aluminized explosives on the ballistic and brisance performance

    Science.gov (United States)

    Kim, Wuhyun; Gwak, Min-cheol; Lee, Young-hun; Yoh, Jack J.

    2018-02-01

    The performance of aluminized high explosives is considered by varying the aluminum (Al) mass fraction in a heterogeneous mixture model. Since the time scales of the characteristic induction and combustion of high explosives and Al particles differ, the process of energy release behind the leading detonation wave front occurs over an extended period of time. For simulating the performance of aluminized explosives with varying Al mass fraction, HMX (1,3,5,7-tetrahexmine-1,3,5,7-tetrazocane) is considered as a base explosive when formulating the multiphase conservation laws of mass, momentum, and energy exchanges between the HMX product gases and Al particles. In the current study, a two-phase model is utilized in order to determine the effects of the Al mass fraction in a condensed phase explosive. First, two types of confined rate stick tests are considered to investigate the detonation velocity and the acceleration ability, which refers to the radial expansion velocity of the confinement shell. The simulation results of the confined rate stick test are compared with the experimental data for the Al mass fraction range of 0%-25%, and the optimal Al mass fraction is provided, which is consistent with the experimental observations. Additionally, a series of plate dent test simulations are conducted, the results of which show the same tendency as those of the experimental tests with varying Al mass fractions.

  11. Magnus approximation in the adiabatic picture

    International Nuclear Information System (INIS)

    Klarsfeld, S.; Oteo, J.A.

    1991-01-01

    A simple approximate nonperturbative method is described for treating time-dependent problems that works well in the intermediate regime far from both the sudden and the adiabatic limits. The method consists of applying the Magnus expansion after transforming to the adiabatic basis defined by the eigenstates of the instantaneous Hamiltonian. A few exactly soluble examples are considered in order to assess the domain of validity of the approximation. (author) 32 refs., 4 figs

  12. Progress in model development to quantify High Explosive Violent Response (HEVR) to mechanical insult

    International Nuclear Information System (INIS)

    Reaugh, J.E.

    2008-01-01

    The rapid release of chemical energy has found application for industrial and military purposes since the invention of gunpowder. Black powder, smokeless powder of various compositions, and pyrotechnics all exhibit the rapid release of energy without detonation when they are being used as designed. The rapidity of energy release for these materials is controlled by adjustments to the particle surface area (propellant grain configuration or powder particle size) in conjunction with the measured pressure-dependent burning rate, which is very subsonic. In this way a manufacturing process can be used to engineer the desired violence of the explosion. Detonations in molecular explosives, in contrast, propagate with a supersonic velocity that depends on the loading density, but is independent of the surface area. In ideal detonations, the reaction is complete within a small distance of the propagating shock front. Non-ideal detonations in molecular and composite explosives proceed with a slower velocity, and the reaction may continue well behind the shock front. We are developing models to describe the circumstances when molecular and composite explosives undergo a rapid release of energy without detonating. The models also apply to the behavior of rocket propellants subject to mechanical insult, whether for accidents (Hazards) or the suite of standardized tests used to assess whether the system can be designated an Insensitive Munition (IM). In the application described here, we are studying an HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) explosive developed in the UK, which is 91% by weight HMX and 9% binder-plasticizer. Most explosives and propellants, when subjected to a mechanical insult, drop or impact that is well below the threshold for detonation have been observed to react violently. This behavior is known as High Explosive Violent Reaction (HEVR). The basis of our model is the observation that the mechanical insult produces damage in a volume of the

  13. Fast fracture: an adiabatic restriction on thermally activated crack propagation

    Energy Technology Data Exchange (ETDEWEB)

    Burns, S.J.

    1978-01-01

    Slow, isothermal, crack propagation is widely suspected to be rate controlled by thermally activated plastic deformation in the crack tip region. Adiabatic conditions are generally established in the fracture modified material at the tip of a crack during fast fracture. The temperature of this material is not the temperature of the specimen and is generally not measured during fast fracture. Thus, a complete thermodynamic description of adiabatic crack propagation data can not be made. When the slow, isothermal, crack propagation mechanisms are assumed to be operative during adiabatic crack propagation then certain predictions can be made. For example: the changes in the driving force due to temperature and rate are always in the opposite sense; there is no minimum in the driving force versus crack velocity without a change in mechanism; the temperature rise in the crack tip fracture modified material is determined mainly by the activation enthalpy for crack propagation; the interpretation of fast fracture structural steel data from simple plastic models is suspect since these materials have dissimilar isothermal temperature dependencies.

  14. Semi adiabatic theory of seasonal Markov processes

    Energy Technology Data Exchange (ETDEWEB)

    Talkner, P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The dynamics of many natural and technical systems are essentially influenced by a periodic forcing. Analytic solutions of the equations of motion for periodically driven systems are generally not known. Simulations, numerical solutions or in some limiting cases approximate analytic solutions represent the known approaches to study the dynamics of such systems. Besides the regime of weak periodic forces where linear response theory works, the limit of a slow driving force can often be treated analytically using an adiabatic approximation. For this approximation to hold all intrinsic processes must be fast on the time-scale of a period of the external driving force. We developed a perturbation theory for periodically driven Markovian systems that covers the adiabatic regime but also works if the system has a single slow mode that may even be slower than the driving force. We call it the semi adiabatic approximation. Some results of this approximation for a system exhibiting stochastic resonance which usually takes place within the semi adiabatic regime are indicated. (author) 1 fig., 8 refs.

  15. Quantum tunneling, adiabatic invariance and black hole spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guo-Ping; Zu, Xiao-Tao [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); Pu, Jin [University of Electronic Science and Technology of China, School of Physical Electronics, Chengdu (China); China West Normal University, College of Physics and Space Science, Nanchong (China); Jiang, Qing-Quan [China West Normal University, College of Physics and Space Science, Nanchong (China)

    2017-05-15

    In the tunneling framework, one of us, Jiang, together with Han has studied the black hole spectroscopy via adiabatic invariance, where the adiabatic invariant quantity has been intriguingly obtained by investigating the oscillating velocity of the black hole horizon. In this paper, we attempt to improve Jiang-Han's proposal in two ways. Firstly, we once again examine the fact that, in different types (Schwarzschild and Painleve) of coordinates as well as in different gravity frames, the adiabatic invariant I{sub adia} = circular integral p{sub i}dq{sub i} introduced by Jiang and Han is canonically invariant. Secondly, we attempt to confirm Jiang-Han's proposal reasonably in more general gravity frames (including Einstein's gravity, EGB gravity and HL gravity). Concurrently, for improving this proposal, we interestingly find in more general gravity theories that the entropy of the black hole is an adiabatic invariant action variable, but the horizon area is only an adiabatic invariant. In this sense, we emphasize the concept that the quantum of the black hole entropy is more natural than that of the horizon area. (orig.)

  16. Adiabatic quantum search algorithm for structured problems

    International Nuclear Information System (INIS)

    Roland, Jeremie; Cerf, Nicolas J.

    2003-01-01

    The study of quantum computation has been motivated by the hope of finding efficient quantum algorithms for solving classically hard problems. In this context, quantum algorithms by local adiabatic evolution have been shown to solve an unstructured search problem with a quadratic speedup over a classical search, just as Grover's algorithm. In this paper, we study how the structure of the search problem may be exploited to further improve the efficiency of these quantum adiabatic algorithms. We show that by nesting a partial search over a reduced set of variables into a global search, it is possible to devise quantum adiabatic algorithms with a complexity that, although still exponential, grows with a reduced order in the problem size

  17. Simulation and analysis of different adiabatic Compressed Air Energy Storage plant configurations

    International Nuclear Information System (INIS)

    Hartmann, Niklas; Vöhringer, O.; Kruck, C.; Eltrop, L.

    2012-01-01

    Highlights: ► We modeled several configurations of an adiabatic Compressed Air Energy Storage (CAES) plant. ► We analyzed changes in efficiency of these configurations under varying operating conditions. ► The efficiency of the adiabatic CAES plant can reach about 70% for the isentropic configuration. ► In the polytropic case, the efficiency is about 10% lower (at about 60%) than in the isentropic configuration. ► The efficiency is highest for a two-stage CAES configuration and highly dependent on the cooling and heating demand. - Abstract: In this paper, the efficiency of one full charging and discharging cycle of several adiabatic Compressed Air Energy Storage (CAES) configurations are analyzed with the help of an energy balance. In the second step main driving factors for the efficiency of the CAES configurations are examined with the help of sensitivity analysis. The results show that the efficiency of the polytropic configuration is about 60%, which is considerable lower than literature values of an adiabatic CAES of about 70%. The high value of 70% is only reached for the isentropic (ideal) configuration. Key element to improve the efficiency is to develop high temperature thermal storages (>600 °C) and temperature resistant materials for compressors. The highest efficiency is delivered by the two-stage adiabatic CAES configuration. In this case the efficiency varies between 52% and 62%, depending on the cooling and heating demand. If the cooling is achieved by natural sources (such as a river), a realistic estimation of the efficiency of adiabatic Compressed Air Energy Storages (without any greenhouse gas emissions due to fuel consumption) is about 60%.

  18. Approximability of optimization problems through adiabatic quantum computation

    CERN Document Server

    Cruz-Santos, William

    2014-01-01

    The adiabatic quantum computation (AQC) is based on the adiabatic theorem to approximate solutions of the Schrödinger equation. The design of an AQC algorithm involves the construction of a Hamiltonian that describes the behavior of the quantum system. This Hamiltonian is expressed as a linear interpolation of an initial Hamiltonian whose ground state is easy to compute, and a final Hamiltonian whose ground state corresponds to the solution of a given combinatorial optimization problem. The adiabatic theorem asserts that if the time evolution of a quantum system described by a Hamiltonian is l

  19. Application of the adiabatic self-consistent collective coordinate method to a solvable model of prolate-oblate shape coexistence

    International Nuclear Information System (INIS)

    Kobayasi, Masato; Matsuyanagi, Kenichi; Nakatsukasa, Takashi; Matsuo, Masayuki

    2003-01-01

    The adiabatic self-consistent collective coordinate method is applied to an exactly solvable multi-O(4) model that is designed to describe nuclear shape coexistence phenomena. The collective mass and dynamics of large amplitude collective motion in this model system are analyzed, and it is shown that the method yields a faithful description of tunneling motion through a barrier between the prolate and oblate local minima in the collective potential. The emergence of the doublet pattern is clearly described. (author)

  20. Development of a surrogate model for analysis of ex-vessel steam explosion in Nordic type BWRs

    Energy Technology Data Exchange (ETDEWEB)

    Grishchenko, Dmitry, E-mail: dmitry@safety.sci.kth.se; Basso, Simone, E-mail: simoneb@kth.se; Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se

    2016-12-15

    Highlights: • Severe accident. • Steam explosion. • Surrogate model. • Sensitivity study. • Artificial neural networks. - Abstract: Severe accident mitigation strategy adopted in Nordic type Boiling Water Reactors (BWRs) employs ex-vessel core melt cooling in a deep pool of water below reactor vessel. Energetic fuel–coolant interaction (steam explosion) can occur during molten core release into water. Dynamic loads can threaten containment integrity increasing the risk of fission products release to the environment. Comprehensive uncertainty analysis is necessary in order to assess the risks. Computational costs of the existing fuel–coolant interaction (FCI) codes is often prohibitive for addressing the uncertainties, including the effect of stochastic triggering time. This paper discusses development of a computationally efficient surrogate model (SM) for prediction of statistical characteristics of steam explosion impulses in Nordic BWRs. The TEXAS-V code was used as the Full Model (FM) for the calculation of explosion impulses. The surrogate model was developed using artificial neural networks (ANNs) and the database of FM solutions. Statistical analysis was employed in order to treat chaotic response of steam explosion impulse to variations in the triggering time. Details of the FM and SM implementation and their verification are discussed in the paper.

  1. Thermal Radiation Effects on Thermal Explosion in Polydisperse Fuel Spray-Probabilistic Model

    Directory of Open Access Journals (Sweden)

    Ophir Navea

    2011-06-01

    Full Text Available We investigate the effect of thermal radiation on the dynamics of a thermal explosion of polydisperse fuel spray with a complete description of the chemistry via a single-step two-reactant model of general order. The polydisperse spray is modeled using a Probability Density Function (PDF. The thermal radiation energy exchange between the evaporation surface of the fuel droplets and the burning gas is described using the Marshak boundary conditions. An explicit expression of the critical condition for thermal explosion limit is derived analytically and represents a generalization of the critical parameter of the classical Semenov theory. Because we investigated the model in the range where the temperature is very high, the effect of the thermal radiation is significant.

  2. Explosion-evaporation model for fragment production in intermediate-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.; Randrup, J.

    1981-01-01

    Nuclear collisions at intermediate energies may create transient systems of hot nuclear matter that decay into many nuclear fragments. The disassembly of such a nuclear fireball is described as a two-stage process. In the primary explosion stage the system quickly fragments into nucleons and composite nuclei according to the available phase space. The explosion produces excited nuclei with half-lives longer than the time associated with the breakup. In the secondary evaporation stage, these nuclei decay, first by sequential emission of light particles (neutrons, protons, alphas), later by electromagnetic radiation. The secondary stage in general changes the relative abundancies of the various fragment species. This general feature makes it essential to take account of the composite fragments before using d/p as a measure of the entropy of the initial source. The formation of unbound nuclei at the explosion stage also has the desirable effect of enhancing the final abundancies of particularly stable nuclei, e.g., 4 He. For neutron-excessive sources the presence of composite nuclei amplifies the ratio of observed neutrons and protons; this effect persists for heavier mirror systems. Predictions of the model are qualitatively compared to available experimental data. The model offers a convenient way to augment existing dynamical models, such as intra-nuclear cascade and nuclear fluid dynamics, to yield actual nuclear fragments rather than merely matter distributions

  3. Explicit Modeling of Solid Ocean Floor in Shallow Underwater Explosions

    Directory of Open Access Journals (Sweden)

    A.P. Walters

    2013-01-01

    Full Text Available Current practices for modeling the ocean floor in underwater explosion simulations call for application of an inviscid fluid with soil properties. A method for modeling the ocean floor as a Lagrangian solid, vice an Eulerian fluid, was developed in order to determine its effects on underwater explosions in shallow water using the DYSMAS solver. The Lagrangian solid bottom model utilized transmitting boundary segments, exterior nodal forces acting as constraints, and the application of prestress to minimize any distortions into the fluid domain. For simplicity, elastic materials were used in this current effort, though multiple constitutive soil models can be applied to improve the overall accuracy of the model. Even though this method is unable to account for soil cratering effects, it does however provide the distinct advantage of modeling contoured ocean floors such as dredged channels and sloped bottoms absent in Eulerian formulations. The study conducted here showed significant differences among the initial bottom reflections for the different solid bottom contours that were modeled. The most important bottom contour effect was the distortion to the gas bubble and its associated first pulse timing. In addition to its utility in bottom modeling, implementation of the non-reflecting boundary along with realistic material models can be used to drastically reduce the size of current fluid domains.

  4. Are the reactions of quinones on graphite adiabatic?

    International Nuclear Information System (INIS)

    Luque, N.B.; Schmickler, W.

    2013-01-01

    Outer sphere electron transfer reactions on pure metal electrodes are often adiabatic and hence independent of the electrode material. Since it is not clear, whether adiabatic electron transfer can also occur on a semi-metal like graphite, we have re-investigated experimental data presented in a recent communication by Nissim et al. [Chemical Communications 48 (2012) 3294] on the reactions of quinones on graphite. We have supplemented their work by DFT calculations and conclude, that these reactions are indeed adiabatic. This contradicts the assertion of Nissim et al. that the rates are proportional to the density of states at the Fermi level

  5. Improving the positive feedback adiabatic logic familiy

    Directory of Open Access Journals (Sweden)

    J. Fischer

    2004-01-01

    Full Text Available Positive Feedback Adiabatic Logic (PFAL shows the lowest energy dissipation among adiabatic logic families based on cross-coupled transistors, due to the reduction of both adiabatic and non-adiabatic losses. The dissipation primarily depends on the resistance of the charging path, which consists of a single p-channel MOSFET during the recovery phase. In this paper, a new logic family called Improved PFAL (IPFAL is proposed, where all n- and pchannel devices are swapped so that the charge can be recovered through an n-channel MOSFET. This allows to decrease the resistance of the charging path up to a factor of 2, and it enables a significant reduction of the energy dissipation. Simulations based on a 0.13µm CMOS process confirm the improvements in terms of power consumption over a large frequency range. However, the same simple design rule, which enables in PFAL an additional reduction of the dissipation by optimal transistor sizing, does not apply to IPFAL. Therefore, the influence of several sources of dissipation for a generic IPFAL gate is illustrated and discussed, in order to lower the power consumption and achieve better performance.

  6. An Explosion Aftershock Model with Application to On-Site Inspection

    Science.gov (United States)

    Ford, Sean R.; Labak, Peter

    2016-01-01

    An estimate of aftershock activity due to a theoretical underground nuclear explosion is produced using an aftershock rate model. The model is developed with data from the Nevada National Security Site, formerly known as the Nevada Test Site, and the Semipalatinsk Test Site, which we take to represent soft-rock and hard-rock testing environments, respectively. Estimates of expected magnitude and number of aftershocks are calculated using the models for different testing and inspection scenarios. These estimates can help inform the Seismic Aftershock Monitoring System (SAMS) deployment in a potential Comprehensive Test Ban Treaty On-Site Inspection (OSI), by giving the OSI team a probabilistic assessment of potential aftershocks in the Inspection Area (IA). The aftershock assessment, combined with an estimate of the background seismicity in the IA and an empirically derived map of threshold magnitude for the SAMS network, could aid the OSI team in reporting. We apply the hard-rock model to a M5 event and combine it with the very sensitive detection threshold for OSI sensors to show that tens of events per day are expected up to a month after an explosion measured several kilometers away.

  7. Adiabatic invariants of the extended KdV equation

    Energy Technology Data Exchange (ETDEWEB)

    Karczewska, Anna [Faculty of Mathematics, Computer Science and Econometrics, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Rozmej, Piotr, E-mail: p.rozmej@if.uz.zgora.pl [Institute of Physics, Faculty of Physics and Astronomy, University of Zielona Góra, Szafrana 4a, 65-246 Zielona Góra (Poland); Infeld, Eryk [National Centre for Nuclear Research, Hoża 69, 00-681 Warszawa (Poland); Rowlands, George [Department of Physics, University of Warwick, Coventry, CV4 7A (United Kingdom)

    2017-01-30

    When the Euler equations for shallow water are taken to the next order, beyond KdV, momentum and energy are no longer exact invariants. (The only one is mass.) However, adiabatic invariants (AI) can be found. When the KdV expansion parameters are zero, exact invariants are recovered. Existence of adiabatic invariants results from general theory of near-identity transformations (NIT) which allow us to transform higher order nonintegrable equations to asymptotically equivalent (when small parameters tend to zero) integrable form. Here we present a direct method of calculations of adiabatic invariants. It does not need a transformation to a moving reference frame nor performing a near-identity transformation. Numerical tests show that deviations of AI from constant values are indeed small. - Highlights: • We suggest a new and simple method for calculating adiabatic invariants of second order wave equations. • It is easy to use and we hope that it will be useful if published. • Interesting numerics included.

  8. Adiabatic burst evaporation from bicontinuous nanoporous membranes

    Science.gov (United States)

    Ichilmann, Sachar; Rücker, Kerstin; Haase, Markus; Enke, Dirk

    2015-01-01

    Evaporation of volatile liquids from nanoporous media with bicontinuous morphology and pore diameters of a few 10 nm is an ubiquitous process. For example, such drying processes occur during syntheses of nanoporous materials by sol–gel chemistry or by spinodal decomposition in the presence of solvents as well as during solution impregnation of nanoporous hosts with functional guests. It is commonly assumed that drying is endothermic and driven by non-equilibrium partial pressures of the evaporating species in the gas phase. We show that nearly half of the liquid evaporates in an adiabatic mode involving burst-like liquid-to-gas conversions. During single adiabatic burst evaporation events liquid volumes of up to 107 μm3 are converted to gas. The adiabatic liquid-to-gas conversions occur if air invasion fronts get unstable because of the built-up of high capillary pressures. Adiabatic evaporation bursts propagate avalanche-like through the nanopore systems until the air invasion fronts have reached new stable configurations. Adiabatic cavitation bursts thus compete with Haines jumps involving air invasion front relaxation by local liquid flow without enhanced mass transport out of the nanoporous medium and prevail if the mean pore diameter is in the range of a few 10 nm. The results reported here may help optimize membrane preparation via solvent-based approaches, solution-loading of nanopore systems with guest materials as well as routine use of nanoporous membranes with bicontinuous morphology and may contribute to better understanding of adsorption/desorption processes in nanoporous media. PMID:25926406

  9. Adiabatically steered open quantum systems: Master equation and optimal phase

    International Nuclear Information System (INIS)

    Salmilehto, J.; Solinas, P.; Ankerhold, J.; Moettoenen, M.

    2010-01-01

    We introduce an alternative way to derive the generalized form of the master equation recently presented by J. P. Pekola et al. [Phys. Rev. Lett. 105, 030401 (2010)] for an adiabatically steered two-level quantum system interacting with a Markovian environment. The original derivation employed the effective Hamiltonian in the adiabatic basis with the standard interaction picture approach but without the usual secular approximation. Our approach is based on utilizing a master equation for a nonsteered system in the first superadiabatic basis. It is potentially efficient in obtaining higher-order equations. Furthermore, we show how to select the phases of the adiabatic eigenstates to minimize the local adiabatic parameter and how this selection leads to states which are invariant under a local gauge change. We also discuss the effects of the adiabatic noncyclic geometric phase on the master equation.

  10. A numerical model for adiabatic shear bands with application to a thick-walled cylinder in 304 stainless steel

    International Nuclear Information System (INIS)

    Liu, Mingtao; Li, Yongchi; Hu, Xiuzhang; Hu, Haibo

    2014-01-01

    The formation of an adiabatic shear band (ASB) experiences three stages: stable plastic flow, nucleation and a fluid-like stage. For different stages, the microstructures of the material undergo great changes. The mechanical behavior of the material in each stage has its own unique characteristics. To describe these characteristics, a multi-stage model for the shear band is proposed. For the stable plastic flow stage, a modified adiabatic J–C constitutive relationship is used. For the nucleation stage, the effects of work hardening and temperature softening are described by a power function of plastic strain. A Newtonian fluid model is used for the fluid-like stage. The formation of a shear band is an instability process. Various defects in the material are perturbation sources, which change the local yield stress. To describe the disturbances, a probability factor is introduced into the macroscopic constitutive relationship. The yield stress in the material is assumed to obey a Gaussian distribution. The multi-stage model combined with a probability factor is applied to simulate the rupture of thick-walled cylinder in 304 Stainless Steel (304SS). A close agreement is found between the simulation and experimental results, such as the failure mechanism, shear band spacing and propagating velocity of the shear band. By combining the experimental results with the simulation results, the importance of the nucleation stage is emphasized. (paper)

  11. Adiabatic compression of elongated field-reversed configurations

    International Nuclear Information System (INIS)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1983-01-01

    The adiabatic compression of an elongated field-reversed configuration (FRC) is computed by using a one-dimensional approximation. The one-dimensional results are checked against a two-dimensional equilibrium code. For ratios of FRC separatrix length to separatrix radius greater than about ten, the one-dimensional results are accurate within 10%. To this accuracy, the adiabatic compression of FRC's can be described by simple analytic formulas

  12. Superconducting system for adiabatic quantum computing

    Energy Technology Data Exchange (ETDEWEB)

    Corato, V [Dipartimento di Ingegneria dell' Informazione, Second University of Naples, 81031 Aversa (Italy); Roscilde, T [Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484 (Canada); Ruggiero, B [Istituto di Cibernetica ' E.Caianiello' del CNR, I-80078, Pozzuoli (Italy); Granata, C [Istituto di Cibernetica ' E.Caianiello' del CNR, I-80078, Pozzuoli (Italy); Silvestrini, P [Dipartimento di Ingegneria dell' Informazione, Second University of Naples, 81031 Aversa (Italy)

    2006-06-01

    We study the Hamiltonian of a system of inductively coupled flux qubits, which has been theoretically proposed for adiabatic quantum computation to handle NP problems. We study the evolution of a basic structure consisting of three coupled rf-SQUIDs upon tuning the external flux bias, and we show that the adiabatic nature of the evolution is guaranteed by the presence of the single-SQUID gap. We further propose a scheme and the first realization of an experimental device suitable for verifying the theoretical results.

  13. Observational tests of non-adiabatic Chaplygin gas

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, S.; Pigozzo, C., E-mail: saulo.carneiro@pq.cnpq.br, E-mail: cpigozzo@ufba.br [Instituto de Física, Universidade Federal da Bahia, Campus de Ondina, Salvador, BA 40210-340 (Brazil)

    2014-10-01

    In a previous paper [1] it was shown that any dark sector model can be mapped into a non-adiabatic fluid formed by two interacting components, one with zero pressure and the other with equation-of-state parameter ω = -1. It was also shown that the latter does not cluster and, hence, the former is identified as the observed clustering matter. This guarantees that the dark matter power spectrum does not suffer from oscillations or instabilities. It applies in particular to the generalised Chaplygin gas, which was shown to be equivalent to interacting models at both background and perturbation levels. In the present paper we test the non-adiabatic Chaplygin gas against the Hubble diagram of type Ia supernovae, the position of the first acoustic peak in the anisotropy spectrum of the cosmic microwave background and the linear power spectrum of large scale structures. We consider two different compilations of SNe Ia, namely the Constitution and SDSS samples, both calibrated with the MLCS2k2 fitter, and for the power spectrum we use the 2dFGRS catalogue. The model parameters to be adjusted are the present Hubble parameter, the present matter density and the Chaplygin gas parameter α. The joint analysis best fit gives α ≈ - 0.5, which corresponds to a constant-rate energy flux from dark energy to dark matter, with the dark energy density decaying linearly with the Hubble parameter. The ΛCDM model, equivalent to α = 0, stands outside the 3σ confidence interval.

  14. Perturbative treatment of possible failures in the adiabatic theorem

    International Nuclear Information System (INIS)

    Vertesi, T.; Englman, R.

    2005-01-01

    Complete text of publication follows. The adiabatic theorem (AT) is one of the oldest and basic results in quantum physics, and has been in widespread use ever since. The theorem concerns the evolution of systems subject to slowly varying Hamiltonians. Roughly, its content is that a system prepared in an instantaneous eigenstate of a time-dependent Hamiltonian H(t) will remain close to an instantaneous eigenstate at later times, provided the Hamiltonian changes sufficiently slowly. The role of the AT in the study of slowly varying quantum mechanical systems spans a vast array of fields and applications. In a recent application the adiabatic geometric phases have been proposed to perform various quantum computational tasks on a naturally fault-tolerant way. Additional interest has arisen in adiabatic processes in connection with the concept of adiabatic quantum computing, where the solution to a problem is encoded in the (unknown) ground state of a (known) Hamiltonian. The evolution of the quantum state is governed by a time-dependent Hamiltonian H(t), starting with an initial Hamiltonian H i with a known ground state and slowly (adiabatically) evolving to the final Hamiltonian H f with the unknown ground state, e.g., H(t) = (1 - t/T )H i + (t/T )H f , (1) where 0 ≤ t/T ≤ 1 and T controls the rate at which H(t) varies. Since the ground state of the system is very robust against external perturbations and decoherence, this scheme offers many advantages compared to the conventional quantum circuit model of quantum computation. The achievable speed-up of adiabatic quantum algorithms (compared to classical methods) depends on the value of the run-time T. The standard AT yields a general criterion to estimate the necessary run-time T, however recently Marzlin and Sanders have claimed that an inconsistency does exist for a particular class of Hamiltonians, so that the condition for the estimate of T may do not hold. Marzlin and Sanders start with a time

  15. Dependence of adiabatic population transfer on pulse profile

    Indian Academy of Sciences (India)

    Control of population transfer by rapid adiabatic passage has been an established technique wherein the exact amplitude profile of the shaped pulse is considered to be insignificant. We study the effect of ultrafast shaped pulses for two-level systems, by density-matrix approach. However, we find that adiabaticity depends ...

  16. Adiabatic, chaotic and quasi-adiabatic charged particle motion in two-dimensional magnetic field reversals

    International Nuclear Information System (INIS)

    Buechner, J.M.

    1989-01-01

    For a number of problems in the Plasma Astrophysics it is necessary to know the laws, which govern the non adiabatic charged particle dynamics in strongly curves magnetic field reversals. These are, e.q., the kinetic theory of the microscopic and macroscopicstability of current sheets in collionless plasma, of microturbulence, causing anomalous resistivity and dissipating currents, the problem of spontaneous reconnection, the formation of non Maxwellian distribution functions, particle acceleration and the use of particles as a diagnostic tool ('tracers'). To find such laws we derived from the differential equations of motion discrete mappings. These mappings allow an investigation of the motion after the break down of the adiabaticity of the magnetic moment. (author). 32 refs.; 5 figs.; 1 tab

  17. Muonic molecules as three-body Coulomb problem in adiabatic approximation

    International Nuclear Information System (INIS)

    Decker, M.

    1994-04-01

    The three-body Coulomb problem is treated within the framework of the hyperspherical adiabatic approach. The surface functions are expanded into Faddeev-type components in order to ensure the equivalent representation of all possible two-body contributions. It is shown that this decomposition reduces the numerical effort considerably. The remaining radial equations are solved both in the extreme and the uncoupled adiabatic approximation to determine the binding energies of the systems (dtμ) and (d 3 Heμ). Whereas the ground state is described very well in the uncoupled adiabatic approximation, the excited states should be treated within the coupled adiabatic approximation to obtain good agreement with variational calculations. (orig.)

  18. Upgraded Analytical Model of the Cylinder Test

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P. Clark [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Lauderbach, Lisa [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Garza, Raul [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Ferranti, Louis [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Vitello, Peter [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2013-03-15

    A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. Finally, the total detonation energy density was locked to the v = 7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

  19. Upgraded Analytical Model of the Cylinder Test

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P. Clark; Lauderbach, Lisa; Garza, Raul; Ferranti, Louis; Vitello, Peter

    2013-03-15

    A Gurney-type equation was previously corrected for wall thinning and angle of tilt, and now we have added shock wave attenuation in the copper wall and air gap energy loss. Extensive calculations were undertaken to calibrate the two new energy loss mechanisms across all explosives. The corrected Gurney equation is recommended for cylinder use over the original 1943 form. The effect of these corrections is to add more energy to the adiabat values from a relative volume of 2 to 7, with low energy explosives having the largest correction. The data was pushed up to a relative volume of about 15 and the JWL parameter ω was obtained directly. The total detonation energy density was locked to the v=7 adiabat energy density, so that the Cylinder test gives all necessary values needed to make a JWL.

  20. Adiabatic compression of elongated field-reversed configurations

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.L.; Tuszewski, M.; Linford, R.K.

    1983-06-01

    The adiabatic compression of an elongated field-reversed configuration (FRC) is computed by using a one-dimensional approximation. The one-dimensional results are checked against a two-dimensional equilibrium code. For ratios of FRC separatrix length to separatrix radius greater than about ten, the one-dimensional results are accurate within 10%. To this accuracy, the adiabatic compression of FRC's can be described by simple analytic formulas.

  1. Modelling of nuclear explosions in hard rock sites

    International Nuclear Information System (INIS)

    Brunish, W.M.; App, F.N.

    1993-01-01

    This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock. In order to learn more about the response of hard rock to underground nuclear explosions, we have attempted to model the PILEDRIVER event. PILEDRIVER was fired on June 2, 1966 in the granite stock of Area 15 at the Nevada Test Site. The working point was at a depth of 462.7 m and the yield was determined to be 61 kt. Numerous surface, sub-surface and free-field measurements were made and analyzed by SRI. An attempt was made to determine the contribution of spall to the teleseismic signal, but proved unsuccessful because most of the data from below-shot-level gauges was lost. Nonetheless, there is quite a bit of good quality data from a variety of locations. We have been able to obtain relatively good agreement with the experimental PILEDRIVER waveforms. In order to do so, we had to model the granodiorite as being considerably weaker than ''good quality'' granite, and it had to undergo considerable weakening due to shock damage as well. In addition, the near-surface layers had to be modeled as being weak and compressible and as have a much lower sound speed than the material at depth. The is consistent with a fractured and jointed material at depth, and a weathered material near the surface

  2. An Influence of Gas Explosions on Dynamic Responses of a Single Degree of Freedom Model

    Directory of Open Access Journals (Sweden)

    Ki-Yeob Kang

    2016-01-01

    Full Text Available Explosion risk analysis (ERA is widely used to derive the dimensioning of accidental loads for design purposes. Computational fluid dynamics (CFD simulations contribute a key part of an ERA and predict possible blast consequences in a hazardous area. Explosion pressures can vary based on the model geometry, the explosion intensity, and explosion scenarios. Dynamic responses of structures under these explosion loads are dependent on a blast wave profile with respect to the magnitude of pressure, duration, and impulse in both positive and negative phases. Understanding the relationship between explosion load profiles and dynamic responses of the target area is important to mitigate the risk of explosion and perform structural design optimization. In the present study, the results of more than 3,000 CFD simulations were considered, and 1.6 million output files were analyzed using a visual basic for applications (VBA tool developed to characterize representative loading shapes. Dynamic response of a structure was investigated in both time and frequency domains using the Fast Fourier Transform (FFT algorithm. In addition, the effects of the residual wave and loading velocity were studied in this paper.

  3. Adiabatic Compression Sensitivity of AF-M315E

    Science.gov (United States)

    2015-07-01

    Brand for their technical expertise and guidance. He also wishes to thank Mr. Stephen McKim from NASA Goddard Space Flight Center for his assistance...Wilson, D. B., and Stoltzfus, J. M. "Adiabatic Compression of Oxygen: Real Fluid Temperatures," 2000. 10Ismail, I. M. K., and Hawkins , T. W. "Adiabatic

  4. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available A temperature state of the solid body may depend both on the conditions of heat exchange with external environment surrounding its surface and on the energy release within the body volume, caused, for example, by the processes in nuclear reactor elements or exothermic chemical reactions, absorption of penetrating radiation energy or transformation of a part of the electrical power into heat with flowing electric current (so-called Joule heat.If with growing temperature the intensity of bulk power density increases, a limited steady temperature state can emerge at which heat extracted to the body surface and released within its volume reaches maximum. Thus, small increments of temperature lead to an increase of heat release, which can not be extracted to the body surface by conduction without further temperature increase. As a result, the steady temperature distribution in the body becomes impossible that determines the state of the thermal explosion, so named due to the fact that in this case the appropriate mathematical model predicts an unlimited temperature increase.A lot of published papers and monographs concerning the study of the combustion and explosion processes in a stationary medium analyse the thermal explosion state. The most famous papers consider a mathematical model to describe a temperature distribution in the case when heat release is because of exothermic chemical reactions the rate of which increases with temperature growth. The dependence of the chemical reaction rate on temperature is usually described by the exponential Arrhenius law, which makes it necessary to consider an essentially nonlinear mathematical model containing differential equation, which includes the term, nonlinearly rising with increasing temperature. Even with simplifying assumptions, this model allows an exact closed form solution only in the case of one-dimensional temperature distributions in the two areas of the canonical form: in the plate, infinite

  5. A Parametric Study to Improve Steam Explosion Models by Using a TROI Test

    International Nuclear Information System (INIS)

    Park, I. K.; Kim, J. H.; Min, B. T.; Hong, S. W.

    2009-01-01

    The overall objective of the OECD programme SERENA (Steam Explosion Resolution for Nuclear Applications) is to consolidate the understanding on FCI phenomenology and assess a method for reliable estimation of the magnitude of loadings for realistic reactor conditions, in order to bring about an understanding and predictability of FCI energetic to desirable levels for a risk management. Main conclusion of phase 1 is that in the absence of pre-existing loads, an in-vessel steam explosion would not challenge the integrity of the vessel, and damage to the cavity is to be expected for an ex-vessel explosion because the level of the loads cannot be predicted due to a large scattering of the results. One major uncertainty that does not allow for a convergence towards consistent predictions is that there is no data on the component distribution in a premixture at the time of the explosion, especially the level of a void. Global void fraction is only available from level-swell measurements. The other major uncertainty is the explosion behavior of corium melts. SERENA phase 2 project which has been conducted since 1st Oct. 2007 is aimed a resolution of the uncertainties on the void fraction and the melt composition effect by performing a limited number of well-designed tests with advanced instrumentations to clarify the nature of a prototypic material with mild steam explosion characteristics and to provide innovative experimental data for a computer code validation. An analytical working group (AWG) is established with the aim of increasing the capabilities the FCI models/codes for use in reactor analyses by complementing the work performed in Phase-1. The main tasks of the group are: performing pre-, posttest calculations, improving the common understanding of those key phenomena such as breakup, void fraction, and fragmentation, addressing the scaling effect and application to the reactor case, In this paper, the pre- and post-test calculation for the first TROI test

  6. Adiabatic and non-adiabatic electron oscillations in a static electric field

    International Nuclear Information System (INIS)

    Wahlberg, C.

    1977-03-01

    The influence of a static electric field on the oscillations of a one-dimensional stream of electrons is investigated. In the weak field limit the oscillations are adiabatic and mode coupling negligible, but becomes significant if the field is tronger. The latter effect is believed to be of importance for the stability of e.g. potential double layers

  7. Quasi-adiabatic Switching for Metal-Island Quantum-dot Cellular Automata

    OpenAIRE

    Toth, Geza; Lent, Craig S.

    2000-01-01

    Recent experiments have demonstrated a working cell suitable for implementing the Quantum-dot Cellular Automata (QCA) paradigm. These experiments have been performed using metal island clusters. The most promising approach to QCA operation involves quasi-adiabatically switching the cells. This has been analyzed extensively in gated semiconductor cells. Here we present a metal island cell structure that makes quasi-adiabatic switching possible. We show how this permits quasi-adiabatic clocking...

  8. Explosive simulants for testing explosive detection systems

    Science.gov (United States)

    Kury, John W.; Anderson, Brian L.

    1999-09-28

    Explosives simulants that include non-explosive components are disclosed that facilitate testing of equipment designed to remotely detect explosives. The simulants are non-explosive, non-hazardous materials that can be safely handled without any significant precautions. The simulants imitate real explosives in terms of mass density, effective atomic number, x-ray transmission properties, and physical form, including moldable plastics and emulsions/gels.

  9. Non-adiabatic effect on Laughlin's argument of the quantum Hall effect

    International Nuclear Information System (INIS)

    Maruyama, I; Hatsugai, Y

    2009-01-01

    We have numerically studied a non-adiabatic charge transport in the quantum Hall system pumped by a magnetic flux, as one of the simplest theoretical realizations of non-adiabatic Thouless pumping. In the adiabatic limit, a pumped charge is quantized, known as Laughlin's argument in a cylindrical lattice. In a uniform electric field, we obtained a formula connecting quantized pumping in the adiabatic limit and no-pumping in the sudden limit. The intermediate region between the two limits is determined by the Landau gap. A randomness or impurity effect is also discussed.

  10. Constraints on the Adiabatic Temperature Change in Magnetocaloric Materials

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

    The thermodynamics of the magnetocaloric effect implies constraints on the allowed variation in the adiabatic temperature change for a magnetocaloric material. An inequality for the derivative of the adiabatic temperature change with respect to temperature is derived for both first- and second...

  11. Analysis and modeling of flow blockage-induced steam explosion events in the High-Flux Isotope Reactor

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.; Georgevich, V.; Lestor, C.W.; Gat, U.; Lepard, B.L.; Cook, D.H.; Freels, J.; Chang, S.J.; Luttrell, C.; Gwaltney, R.C.; Kirkpatrick, J.

    1993-01-01

    This paper provides a perspective overview of the analysis and modeling work done to evaluate the threat from steam explosion loads in the High-Flux Isotope Reactor during flow blockage events. The overall workscope included modeling and analysis of core melt initiation, melt propagation, bounding and best-estimate steam explosion energetics, vessel failure from fracture, bolts failure from exceedance of elastic limits, and finally, missile evolution and transport. Aluminum ignition was neglected. Evaluations indicated that a thermally driven steam explosion with more than 65 MJ of energy insertion in the core region over several miliseconds would be needed to cause a sufficiently energetic missile with a capacity to cause early confinement failure. This amounts to about 65% of the HFIR core mass melting and participating in a steam explosion. Conservative melt propagation analyses have indicated that at most only 24% of the HFIR core mass could melt during flow blockage events under full-power conditions. Therefore, it is judged that the HFIR vessel and top head structure will be able to withstand loads generated from thermally driven steam explosions initiated by any credible flow blockage event. A substantial margin to safety was demonstrated

  12. Progress in the development of explosives materials detectors

    International Nuclear Information System (INIS)

    Williams, W.D.; Conrad, F.J.; Sandlin, L.L.; Burrows, T.A.

    1978-01-01

    Five hand-held explosives vapor detectors (Elscint Model EXD-2, ITI Model 70, Leigh-Marsland Model S-201, Pye Dynamics Model PD.2.A, and Xonics Model GC-710) were evaluated for sensitivity to a variety of explosives, identification of false alarm agents, and general performance and maintenance characteristics. The results of this evaluation, as presented, indicate that there is no single explosives detector which is best-suited for use at all nuclear facilities. Rather, there are several site-specific elements which must be considered when choosing an explosives detector. There are several new explosives detector technologies being developed which will out-perform existing commercial equipment. Some of these new detectors may be commercially available by the end of fiscal year 1980 and will be cost-effective to purchase and operate. The following areas of explosives detection research are discussed: nitrogen-phosphorous detectors, plasma chromatography, mass spectroscopy, small animal olfactory, vapor preconcentration, nuclear quadrupole resonance, far infrared radiation imaging, nuclear magnetic resonance, thermal neutron activation, and computerized tomography

  13. Experimental study on the adiabatic shear bands

    International Nuclear Information System (INIS)

    Affouard, J.

    1984-07-01

    Four martensitic steels (Z50CDV5 steel, 28CND8 steel, 35NCDV16 steel and 4340 steel) with different hardness between 190 and 600 Hsub(B) (Brinell hardness), have been studied by means of dynamic compressive tests on split Hopkinson pressure bar. Microscopic observations show that the fracture are associated to the development of adiabatic shear bands (except 4340 steel with 190 Hsub(B) hardness). By means of tests for which the deformation is stopped at predetermined levels, the measurement of shear and hardness inside the band and the matrix indicates the chronology of this phenomenon: first the localization of shear, followed by the formation of adiabatic shear band and ultimatly crack initiation and propagation. These results correlated with few simulations by finite elements have permitted to suggest two mecanisms of deformation leading to the formation of adiabatic shear bands in this specific test [fr

  14. Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

    Science.gov (United States)

    Adame, J.; Warzel, S.

    2015-11-01

    In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM.

  15. Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

    International Nuclear Information System (INIS)

    Adame, J.; Warzel, S.

    2015-01-01

    In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM

  16. Analysis and modeling of flow-blockage-induced steam explosion events in the high-flux isotope reactor

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.; Georgevich, V.; Nestor, C.W.; Gat, U.; Lepard, B.L.; Cook, D.H.; Freels, J.; Chang, S.J.; Luttrell, C.; Gwaltney, R.C.

    1994-01-01

    This article provides a perspective overview of the analysis and modeling work done to evaluate the threat from steam explosion loads in the High-Flux Isotope Reactor (HFIR) during flow blockage events. The overall work scope included modeling and analysis of core-melt initiation, melt propagation, bounding and best-estimate steam explosion energetics, vessel failure from fracture, bolts failure from exceedance of elastic limits, and, finally, missile evolution and transport. Aluminum ignition was neglected. Evaluations indicated that a thermally driven steam explosion with more than 65 MJ of energy insertion in the core region over several milliseconds would be needed to cause a sufficiently energetic missile with a capacity to cause early confinement failure. This amounts to about 65% of the HFIR core mass melting and participating in a steam explosion. Conservative melt propagation analyses have indicated that at most only 24% of the HFIR core mass could melt during flow blockage events under full-power conditions. 19 refs., 11 figs

  17. A design study of non-adiabatic electron guns

    International Nuclear Information System (INIS)

    Barroso, J.J.; Stellati, C.

    1994-01-01

    The design of a non-adiabatic gun capable of producing a 10 A, 50 KeV high-quality laminar electron beam is reported. In contrast to the magnetron injection gun with a conical cathode, where the beam is generated initially with a transverse velocity component, in the non-adiabatic gun electrons are extracted in a direction parallel to the axial guide magnetic field. The beam electrons acquire cyclotron motion as result of non-adiabatic processes in a strong non uniform electric field across the modulation anode. Such an extraction method gives rise to favourable features that are explored throughout the work. An extensive numerical simulation study has also been done to minimize velocity and energy spreads. (author). 3 refs, 5 figs, 1 tab

  18. Adiabatic and isothermal resistivities

    International Nuclear Information System (INIS)

    Fishman, R.S.

    1989-01-01

    The force-balance method is used to calculate the isothermal resistivity to first order in the electric field. To lowest order in the impurity potential, the isothermal resistivity disagrees with the adiabatic results of the Kubo formula and the Boltzmann equation. However, an expansion of the isothermal resistivity in powers of the impurity potential is divergent, with two sets of divergent terms. The first set arises from the density matrix of the relative electron-phonon system. The second set arises from the explicit dependence of the density matrix on the electric field, which was ignored by force-balance calculations. These divergent contributions are calculated inductively, by applying a recursion relation for the Green's functions. Using the λ 2 t→∞ limit of van Hove, I show that the resummation of these divergent terms yields the same result for the resistivity as the adiabatic calculations, in direct analogy with the work of Argyres and Sigel, and Huberman and Chester

  19. Adiabatic quantum computation and quantum annealing theory and practice

    CERN Document Server

    McGeoch, Catherine C

    2014-01-01

    Adiabatic quantum computation (AQC) is an alternative to the better-known gate model of quantum computation. The two models are polynomially equivalent, but otherwise quite dissimilar: one property that distinguishes AQC from the gate model is its analog nature. Quantum annealing (QA) describes a type of heuristic search algorithm that can be implemented to run in the ``native instruction set'''' of an AQC platform. D-Wave Systems Inc. manufactures {quantum annealing processor chips} that exploit quantum properties to realize QA computations in hardware. The chips form the centerpiece of a nov

  20. Teleportation of an Unknown Atomic State via Adiabatic Passage

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We propose a scheme for teleporting an unknown atomic state via adiabatic passage. Taking advantage of adiabatic passage, the atom has no probability of being excited and thus the atomic spontaneous emission is suppressed.We also show that the fidelity can reach 1 under certain condition.

  1. Two ways to model voltage-current curves of adiabatic MgB2 wires

    International Nuclear Information System (INIS)

    Stenvall, A; Korpela, A; Lehtonen, J; Mikkonen, R

    2007-01-01

    Usually overheating of the sample destroys attempts to measure voltage-current curves of conduction cooled high critical current MgB 2 wires at low temperatures. Typically, when a quench occurs a wire burns out due to massive heat generation and negligible cooling. It has also been suggested that high n values measured with MgB 2 wires and coils are not an intrinsic property of the material but arise due to heating during the voltage-current measurement. In addition, quite recently low n values for MgB 2 wires have been reported. In order to find out the real properties of MgB 2 an efficient computational model is required to simulate the voltage-current measurement. In this paper we go back to basics and consider two models to couple electromagnetic and thermal phenomena. In the first model the magnetization losses are computed according to the critical state model and the flux creep losses are considered separately. In the second model the superconductor resistivity is described by the widely used power law. Then the coupled current diffusion and heat conduction equations are solved with the finite element method. In order to compare the models, example runs are carried out with an adiabatic slab. Both models produce a similar significant temperature rise near the critical current which leads to fictitiously high n values

  2. Research topics in explosives - a look at explosives behaviors

    International Nuclear Information System (INIS)

    Maienschein, J L

    2014-01-01

    The behaviors of explosives under many conditions - e.g., sensitivity to inadvertent reactions, explosion, detonation - are controlled by the chemical and physical properties of the explosive materials. Several properties are considered for a range of improvised and conventional explosives. Here I compare these properties across a wide range of explosives to develop an understanding of explosive behaviors. For improvised explosives, which are generally heterogeneous mixtures of ingredients, a range of studies is identified as needed to more fully understand their behavior and properties. For conventional explosives, which are generally comprised of crystalline explosive molecules held together with a binder, I identify key material properties that determine overall sensitivity, including the extremely safe behavior of Insensitive High Explosives, and discuss an approach to predicting the sensitivity or insensitivity of an explosive.

  3. Upon the reconstruction of accidents triggered by tire explosion. Analytical model and case study

    Science.gov (United States)

    Gaiginschi, L.; Agape, I.; Talif, S.

    2017-10-01

    Accident Reconstruction is important in the general context of increasing road traffic safety. In the casuistry of traffic accidents, those caused by tire explosions are critical under the severity of consequences, because they are usually happening at high speeds. Consequently, the knowledge of the running speed of the vehicle involved at the time of the tire explosion is essential to elucidate the circumstances of the accident. The paper presents an analytical model for the kinematics of a vehicle which, after the explosion of one of its tires, begins to skid, overturns and rolls. The model consists of two concurent approaches built as applications of the momentum conservation and energy conservation principles, and allows determination of the initial speed of the vehicle involved, by running backwards the sequences of the road event. The authors also aimed to both validate the two distinct analytical approaches by calibrating the calculation algorithms on a case study

  4. Nonadiabatic exchange dynamics during adiabatic frequency sweeps.

    Science.gov (United States)

    Barbara, Thomas M

    2016-04-01

    A Bloch equation analysis that includes relaxation and exchange effects during an adiabatic frequency swept pulse is presented. For a large class of sweeps, relaxation can be incorporated using simple first order perturbation theory. For anisochronous exchange, new expressions are derived for exchange augmented rotating frame relaxation. For isochronous exchange between sites with distinct relaxation rate constants outside the extreme narrowing limit, simple criteria for adiabatic exchange are derived and demonstrate that frequency sweeps commonly in use may not be adiabatic with regard to exchange unless the exchange rates are much larger than the relaxation rates. Otherwise, accurate assessment of the sensitivity to exchange dynamics will require numerical integration of the rate equations. Examples of this situation are given for experimentally relevant parameters believed to hold for in-vivo tissue. These results are of significance in the study of exchange induced contrast in magnetic resonance imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

    Understanding the causes and effects of explosions is important to experts in a broad range of disciplines, including the military, industrial and environmental research, aeronautic engineering, and applied mathematics. Offering an introductory review of historic research, Shock Waves and Explosions brings analytic and computational methods to a wide audience in a clear and thorough way. Beginning with an overview of the research on combustion and gas dynamics in the 1970s and 1980s, the author brings you up to date by covering modeling techniques and asymptotic and perturbative methods and ending with a chapter on computational methods.Most of the book deals with the mathematical analysis of explosions, but computational results are also included wherever they are available. Historical perspectives are provided on the advent of nonlinear science, as well as on the mathematical study of the blast wave phenomenon, both when visualized as a point explosion and when simulated as the expansion of a high-pressure ...

  6. The challenge of modeling fuel–coolant interaction: Part II – Steam explosion

    Energy Technology Data Exchange (ETDEWEB)

    Meignen, Renaud, E-mail: renaud.meignen@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Raverdy, Bruno [Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PSN-RES/SAG, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Picchi, Stephane; Lamome, Julien [Communication and Systèmes, 22 avenue Galilée, 92350 Le Plessis Robinson (France)

    2014-12-15

    Highlights: • We present the status modeling of steam explosion in the computer code MC3D (a first paper is devoted to premixing stage of FCI). • We also propose a general state of the art, highlighting recent improvements in understanding and modeling, remaining difficulties, controversies and needs. • We highlight the need for improving the understanding of the melt fragmentation and oxidation. • The verification basis is presented. - Abstract: In the course of a severe accident in a nuclear power plant cooled or moderated by water, the core might melt and flow down into the water. Under certain circumstances, a steam explosion might develop during the mixing of the melt and the water. Such an explosion, if occurring in the reactor pit of a PWR or BWR, might challenge the containment integrity and is thus an important issue for nuclear safety. This paper aims at presenting both a status of research and understanding of the phenomenon and the main characteristics of the models developed in the 3-dimensional computer code MC3D. We make a particular emphasis on the underlying difficulties, uncertainties and needs for further improvements. We discuss more particularly the two major phenomena that are the fine fragmentation and the pressurization process. We also give insights on the impact of melt solidification on the fragmentation and on the issue of oxidation. The verification basis of the models is discussed and finally, an example of 3D calculation is presented to highlight the current code capabilities.

  7. Estimation of the adiabatic energy limit versus beta in Baseball II

    International Nuclear Information System (INIS)

    Foote, J.H.

    1976-01-01

    Several estimates of the adiabatic energy limit versus beta in Baseball II are summarized, and the calculational methods used to obtain them are described. Some estimates are based on analytic expressions; for others, particle orbits are calculated, magnetic-moment jumps are inspected, and adiabatic limits then derived. The results are sensitive to the assumed variation of the combined vacuum-plus-plasma magnetic field. The calculated adiabatic energy limit falls rapidly with beta, even for a gradual magnetic-field variation. If we assume a sharp depression in the axial profile of the combined magnetic field for a finite-beta plasma, the adiabatic limit can be further markedly reduced

  8. Thermal chemical-mechanical reactive flow model of shock initiation in solid explosives

    International Nuclear Information System (INIS)

    Nicholls, A.L. III; Tarver, C.M.

    1998-01-01

    The three dimensional Arbitrary Lagrange Eulerian hydrodynamic computer code ALE3D with fully coupled thermal-chemical-mechanical material models provides the framework for the development of a physically realistic model of shock initiation and detonation of solid explosives. The processes of hot spot formation during shock compression, subsequent ignition of reaction or failure to react, growth of reaction in individual hot spots, and coalescence of reacting hot spots during the transition to detonation can now be modeled using Arrhenius chemical kinetic rate laws and heat transfer to propagate the reactive flow. This paper discusses the growth rates of reacting hot spots in HMX and TATB and their coalescence during shock to detonation transition. Hot spot deflagration rates are found to be fast enough to consume explosive particles less than 10 mm in diameter during typical shock duration times, but larger particles must fragment and create more reactive surface area in order to be rapidly consumed

  9. Adiabatic passage and ensemble control of quantum systems

    International Nuclear Information System (INIS)

    Leghtas, Z; Sarlette, A; Rouchon, P

    2011-01-01

    This paper considers population transfer between eigenstates of a finite quantum ladder controlled by a classical electric field. Using an appropriate change of variables, we show that this setting can be set in the framework of adiabatic passage, which is known to facilitate ensemble control of quantum systems. Building on this insight, we present a mathematical proof of robustness for a control protocol-chirped pulse-practised by experimentalists to drive an ensemble of quantum systems from the ground state to the most excited state. We then propose new adiabatic control protocols using a single chirped and amplitude-shaped pulse, to robustly perform any permutation of eigenstate populations, on an ensemble of systems with unknown coupling strengths. These adiabatic control protocols are illustrated by simulations on a four-level ladder.

  10. Evaluation of the Thermochemical Code - CHEETAH 2.0 for Modelling Explosives Performance

    National Research Council Canada - National Science Library

    Lu, Jing

    2001-01-01

    The Lawrence Livermore National Laboratory CHEETAH 2.0 program has been used to analyse a number of conventional ideal explosive ingredients, ideal explosive compositions, non-ideal explosive compositions, and new and proposed explosives...

  11. PULSATING REVERSE DETONATION MODELS OF TYPE Ia SUPERNOVAE. II. EXPLOSION

    International Nuclear Information System (INIS)

    Bravo, Eduardo; Garcia-Senz, Domingo; Cabezon, Ruben M.; DomInguez, Inmaculada

    2009-01-01

    Observational evidences point to a common explosion mechanism of Type Ia supernovae based on a delayed detonation of a white dwarf (WD). However, all attempts to find a convincing ignition mechanism based on a delayed detonation in a destabilized, expanding, white dwarf have been elusive so far. One of the possibilities that has been invoked is that an inefficient deflagration leads to pulsation of a Chandrasekhar-mass WD, followed by formation of an accretion shock that confines a carbon-oxygen rich core, while transforming the kinetic energy of the collapsing halo into thermal energy of the core, until an inward moving detonation is formed. This chain of events has been termed Pulsating Reverse Detonation (PRD). In this work, we present three-dimensional numerical simulations of PRD models from the time of detonation initiation up to homologous expansion. Different models characterized by the amount of mass burned during the deflagration phase, M defl , give explosions spanning a range of kinetic energies, K ∼ (1.0-1.2) x 10 51 erg, and 56 Ni masses, M( 56 Ni) ∼ 0.6-0.8 M sun , which are compatible with what is expected for typical Type Ia supernovae. Spectra and light curves of angle-averaged spherically symmetric versions of the PRD models are discussed. Type Ia supernova spectra pose the most stringent requirements on PRD models.

  12. Explosion Source Model Development in Support of Seismic Monitoring Technologies: New Models Accounting for Shock-Induced Tensile Failure

    Science.gov (United States)

    2008-09-01

    values for nuclear explosions at the Semipalatinsk Test Site (STS) will be inferred in the same way they were for NTS. Comparisons between K values...K > ~3 in Poisson media. Most Nevada Test Site (NTS) observations support ~1 < K < 3, and as such the new model predicts lower Ms compared to the...explosions at the two test sites and for two different containment rules are summarized in Table 1 below. F1 is found to be positive for NTS, as we

  13. Topological structures of adiabatic phase for multi-level quantum systems

    International Nuclear Information System (INIS)

    Liu Zhengxin; Zhou Xiaoting; Liu Xin; Liu Xiongjun; Chen Jingling

    2007-01-01

    The topological properties of adiabatic gauge fields for multi-level (three-level in particular) quantum systems are studied in detail. Similar to the result that the adiabatic gauge field for SU(2) systems (e.g. two-level quantum system or angular momentum systems, etc) has a monopole structure, the curvature 2-forms of the adiabatic holonomies for SU(3) three-level and SU(3) eight-level quantum systems are shown to have monopole-like (for all levels) or instanton-like (for the degenerate levels) structures

  14. An integral model of plume rise from high explosive detonations

    International Nuclear Information System (INIS)

    Boughton, B.A.; De Laurentis, J.M.

    1987-01-01

    A numerical model has been developed which provides a complete description of the time evolution of both the physical and thermodynamic properties of the cloud formed when a high explosive is detonated. This simulation employs the integral technique. The model equations are derived by integrating the three-dimensional conservation equations of mass, momentum and energy over the plume cross section. Assumptions are made regarding (a) plume symmetry; (b) the shape of profiles of velocity, temperature, etc. across the plume; and (c) the methodology for simulating entrainment and the effects of the crossflow induced pressure drag force on the plume. With these assumptions, the integral equations can be reduced to a set of ordinary differential equations on the plume centerline variables. Only the macroscopic plume characteristics, e.g., plume radius, centerline height, temperature and density, are predicted; details of the plume intrastructure are ignored. The model explicitly takes into account existing meteorology and has been expanded to consider the alterations in plume behavior which occur when aqueous foam is used as a dispersal mitigating material. The simulation was tested by comparison with field measurements of cloud top height and diameter. Predictions were within 25% of field observations over a wide range of explosive yield and atmospheric stability

  15. Expediency of application of explosion-relief constructions to ensure explosion resistance of production buildings

    Directory of Open Access Journals (Sweden)

    Lyapin Anton

    2016-01-01

    Full Text Available The article presents a model of economic evaluation and selection of explosion-relief constructions (ERC, as well as determination of explosion protection efficiency of buildings and structures provided on a stage of construction. It has been shown that definition of economic efficiency of ERС is the evaluation of its application for buildings with remote or automatically controlled production. It has been determined that an important role in design of explosive industrial facilities is played by selection of the economically feasible and effective materials for ERC. When selecting materials it is necessary to consider probability and yield of explosions. Necessity to create the methods allow considering such probability has been revealed.

  16. A single cell model for pretreatment of wood by microwave explosion

    Science.gov (United States)

    Xianjun Li; Yongdong Zhou; Yonglin Yan; Zhiyong Cai; Fu Feng

    2010-01-01

    A theoretical model was developed to better understand the process of microwave explosion treatment of wood cells. The cell expansion and critical conditions concerning pressure and temperature of ray parenchyma cells in Eucalyptus urophylla were simulated during microwave pretreatment. The results indicate that longitudinal and circumferential stresses were generated...

  17. On Adiabatic Processes at the Elementary Particle Level

    OpenAIRE

    A, Michaud

    2016-01-01

    Analysis of adiabatic processes at the elementary particle level and of the manner in which they correlate with the principle of conservation of energy, the principle of least action and entropy. Analysis of the initial and irreversible adiabatic acceleration sequence of newly created elementary particles and its relation to these principles. Exploration of the consequences if this first initial acceleration sequence is not subject to the principle of conservation.

  18. Interplay between electric and magnetic effect in adiabatic polaritonic systems

    KAUST Repository

    Alabastri, Alessandro; Toma, Andrea; Liberale, Carlo; Chirumamilla, Manohar; Giugni, Andrea; De Angelis, Francesco De; Das, Gobind; Di Fabrizio, Enzo M.; Proietti Zaccaria, Remo

    2013-01-01

    We report on the possibility of realizing adiabatic compression of polaritonic wave on a metallic conical nano-structure through an oscillating electric potential (quasi dynamic regime). By comparing this result with an electromagnetic wave excitation, we were able to relate the classical lighting-rod effect to adiabatic compression. Furthermore, we show that while the magnetic contribution plays a marginal role in the formation of adiabatic compression, it provides a blue shift in the spectral region. In particular, magnetic permeability can be used as a free parameter for tuning the polaritonic resonances. The peculiar form of adiabatic compression is instead dictated by both the source and the metal permittivity. The analysis is performed by starting from a simple electrostatic system to end with the complete electromagnetic one through intermediate situations such as the quasi-electrostatic and quasi-dynamic regimes. Each configuration is defined by a particular set of equations which allows to clearly determine the individual role played by the electric and magnetic contribution in the generation of adiabatic compression. We notice that these findings can be applied for the realization of a THz nano-metric generator. © 2013 Optical Society of America.

  19. Adiabatic condition and the quantum hitting time of Markov chains

    International Nuclear Information System (INIS)

    Krovi, Hari; Ozols, Maris; Roland, Jeremie

    2010-01-01

    We present an adiabatic quantum algorithm for the abstract problem of searching marked vertices in a graph, or spatial search. Given a random walk (or Markov chain) P on a graph with a set of unknown marked vertices, one can define a related absorbing walk P ' where outgoing transitions from marked vertices are replaced by self-loops. We build a Hamiltonian H(s) from the interpolated Markov chain P(s)=(1-s)P+sP ' and use it in an adiabatic quantum algorithm to drive an initial superposition over all vertices to a superposition over marked vertices. The adiabatic condition implies that, for any reversible Markov chain and any set of marked vertices, the running time of the adiabatic algorithm is given by the square root of the classical hitting time. This algorithm therefore demonstrates a novel connection between the adiabatic condition and the classical notion of hitting time of a random walk. It also significantly extends the scope of previous quantum algorithms for this problem, which could only obtain a full quadratic speedup for state-transitive reversible Markov chains with a unique marked vertex.

  20. Numerical simulation of transient, adiabatic, two-dimensional two-phase flow using the two-fluid model

    International Nuclear Information System (INIS)

    Neves Conti, T. das.

    1983-01-01

    A numerical method is developed to simulate adiabatic, transient, two-dimensional two-phase flow. The two-fluid model is used to obtain the mass and momentum conservation equations. These are solved by an iterative algorithm emphoying a time-marching scheme. Based on the corrective procedure of Hirt and Harlow a poisson equation is derived for the pressure field. This equation is finite-differenced and solved by a suitable matrix inversion technique. In the absence of experiment results several numerical tests were made in order to chec accuracy, convergence and stability of the proposed method. Several tests were also performed to check whether the behavior of void fraction and phasic velocities conforms with previous observations. (Author) [pt

  1. Plutonium explosive dispersal modeling using the MACCS2 computer code

    International Nuclear Information System (INIS)

    Steele, C.M.; Wald, T.L.; Chanin, D.I.

    1998-01-01

    The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ''Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants''. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology

  2. Plutonium explosive dispersal modeling using the MACCS2 computer code

    Energy Technology Data Exchange (ETDEWEB)

    Steele, C.M.; Wald, T.L.; Chanin, D.I.

    1998-11-01

    The purpose of this paper is to derive the necessary parameters to be used to establish a defensible methodology to perform explosive dispersal modeling of respirable plutonium using Gaussian methods. A particular code, MACCS2, has been chosen for this modeling effort due to its application of sophisticated meteorological statistical sampling in accordance with the philosophy of Nuclear Regulatory Commission (NRC) Regulatory Guide 1.145, ``Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants``. A second advantage supporting the selection of the MACCS2 code for modeling purposes is that meteorological data sets are readily available at most Department of Energy (DOE) and NRC sites. This particular MACCS2 modeling effort focuses on the calculation of respirable doses and not ground deposition. Once the necessary parameters for the MACCS2 modeling are developed and presented, the model is benchmarked against empirical test data from the Double Tracks shot of project Roller Coaster (Shreve 1965) and applied to a hypothetical plutonium explosive dispersal scenario. Further modeling with the MACCS2 code is performed to determine a defensible method of treating the effects of building structure interaction on the respirable fraction distribution as a function of height. These results are related to the Clean Slate 2 and Clean Slate 3 bunkered shots of Project Roller Coaster. Lastly a method is presented to determine the peak 99.5% sector doses on an irregular site boundary in the manner specified in NRC Regulatory Guide 1.145 (1983). Parametric analyses are performed on the major analytic assumptions in the MACCS2 model to define the potential errors that are possible in using this methodology.

  3. Interacting adiabatic quantum motor

    Science.gov (United States)

    Bruch, Anton; Kusminskiy, Silvia Viola; Refael, Gil; von Oppen, Felix

    2018-05-01

    We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

  4. Collapse and equilibrium of rotating, adiabatic clouds

    International Nuclear Information System (INIS)

    Boss, A.P.

    1980-01-01

    A numerical hydrodynamics computer code has been used to follow the collapse and establishment of equilibrium of adiabatic gas clouds restricted to axial symmetry. The clouds are initially uniform in density and rotation, with adiabatic exponents γ=5/3 and 7/5. The numerical technique allows, for the first time, a direct comparison to be made between the dynamic collapse and approach to equilibrium of unconstrained clouds on the one hand, and the results for incompressible, uniformly rotating equilibrium clouds, and the equilibrium structures of differentially rotating polytropes, on the other hand

  5. Simplified scaling model for the THETA-pinch

    Science.gov (United States)

    Ewing, K. J.; Thomson, D. B.

    1982-02-01

    A simple ID scaing model for the fast Theta pinch was developed and written as a code that would be flexible, inexpensive in computer time, and readily available for use with the Los Alamos explosive-driven high magnetic field program. The simplified model uses three successive separate stages: (1) a snowplow-like radial implosion, (2) an idealized resistive annihilation of reverse bias field, and (3) an adiabatic compression stage of a Beta = 1 plasma for which ideal pressure balance is assumed to hold. The code uses one adjustable fitting constant whose value was first determined by comparison with results from the Los Alamos Scylla III, Scyllacita, and Scylla IA Theta pinches.

  6. Acoustic solitary waves in dusty and/or multi-ion plasmas with cold, adiabatic, and hot constituents

    International Nuclear Information System (INIS)

    Verheest, Frank; Hellberg, Manfred A.; Kourakis, Ioannis

    2008-01-01

    Large nonlinear acoustic waves are discussed in a four-component plasma, made up of two superhot isothermal species, and two species with lower thermal velocities, being, respectively, adiabatic and cold. First a model is considered in which the isothermal species are electrons and ions, while the cooler species are positive and/or negative dust. Using a Sagdeev pseudopotential formalism, large dust-acoustic structures have been studied in a systematic way, to delimit the compositional parameter space in which they can be found, without restrictions on the charges and masses of the dust species and their charge signs. Solitary waves can only occur for nonlinear structure velocities smaller than the adiabatic dust thermal velocity, leading to a novel dust-acoustic-like mode based on the interplay between the two dust species. If the cold and adiabatic dust are oppositely charged, only solitary waves exist, having the polarity of the cold dust, their parameter range being limited by infinite compression of the cold dust. However, when the charges of the cold and adiabatic species have the same sign, solitary structures are limited for increasing Mach numbers successively by infinite cold dust compression, by encountering the adiabatic dust sonic point, and by the occurrence of double layers. The latter have, for smaller Mach numbers, the same polarity as the charged dust, but switch at the high Mach number end to the opposite polarity. Typical Sagdeev pseudopotentials and solitary wave profiles have been presented. Finally, the analysis has nowhere used the assumption that the dust would be much more massive than the ions and hence, one or both dust species can easily be replaced by positive and/or negative ions and the conclusions will apply to that plasma model equally well. This would cover a number of different scenarios, such as, for example, very hot electrons and ions, together with a mix of adiabatic ions and dust (of either polarity) or a very hot electron

  7. Application of static fuel management codes for determination of the neutron noise using the adiabatic approximation

    International Nuclear Information System (INIS)

    Garis, N.S.; Karlsson, J.K.H.; Pazsit, I.

    2000-01-01

    The neutron noise, induced by a rod manoeuvring experiment in a pressurized water reactor, has been calculated by the incore fuel management code SIMULATE. The space- and frequency-dependent noise in the thermal group was calculated through the adiabatic approximation in three dimensions and two-group theory, with the spatial resolution of the nodal model underlying the SIMULATE algorithm. The calculated spatial noise profiles were interpreted on physical terms. They were also compared with model calculations in a 2-D one-group model, where various approximations as well as the full space-dependent response could be calculated. The adiabatic results obtained with SIMULATE can be regarded as reliable for sub-plateau frequencies (below 0.1 Hz). (orig.) [de

  8. Calculation of a hydrogen molecule in the adiabatic approximation

    International Nuclear Information System (INIS)

    Vukajlovich, F.R.; Mogilevskij, O.A.; Ponomarev, L.I.

    1979-01-01

    The adiabatic approximation js used for calculating the energy levels of a hydrogen molecule, i.e. of the simplest four-body system with a Coulomb interaction. The aim of this paper is the investigation of the possible use of the adiabatic method in the molecular problems. The most effective regions of its application are discussed. An infinite system of integro-differential equations is constructed, which describes the hydrogen molecule in the adiabatic approximation with the effective potentials taking into account the corrections to the nuclear motion. The energy of the first three vibrational states of the hydrogen molecule is calculated and compared with the experimental data. The convergence of the method is discussed

  9. CFD analysis of gas explosions vented through relief pipes.

    Science.gov (United States)

    Ferrara, G; Di Benedetto, A; Salzano, E; Russo, G

    2006-09-21

    Vent devices for gas and dust explosions are often ducted to safe locations by means of relief pipes. However, the presence of the duct increases the severity of explosion if compared to simply vented vessels (i.e. compared to cases where no duct is present). Besides, the identification of the key phenomena controlling the violence of explosion has not yet been gained. Multidimensional models coupling, mass, momentum and energy conservation equations can be valuable tools for the analysis of such complex explosion phenomena. In this work, gas explosions vented through ducts have been modelled by a two-dimensional (2D) axi-symmetric computational fluid dynamic (CFD) model based on the unsteady Reynolds Averaged Navier Stokes (RANS) approach in which the laminar, flamelet and distributed combustion models have been implemented. Numerical test have been carried out by varying ignition position, duct diameter and length. Results have evidenced that the severity of ducted explosions is mainly driven by the vigorous secondary explosion occurring in the duct (burn-up) rather than by the duct flow resistance or acoustic enhancement. Moreover, it has been found out that the burn-up affects explosion severity due to the reduction of venting rate rather than to the burning rate enhancement through turbulization.

  10. Magnetization Transfer Effects on the Efficiency of Flow-driven Adiabatic Fast Passage Inversion of Arterial Blood

    OpenAIRE

    Hernandez-Garcia, Luis; Lewis, David P.; Moffat, Bradford; Branch, Craig A.

    2007-01-01

    Continuous arterial spin labeling experiments typically use flow-driven adiabatic fast passage (AFP) inversion of the arterial blood water protons. In this article, we measure the effect of magnetization transfer in blood and how it affects the inversion label. We use modified Bloch equations to model flow-driven adiabatic inversion in the presence of magnetization transfer in blood flowing at velocities from 1 to 30 cm/s in order to explain our findings. Magnetization transfer results in a r...

  11. New Mix Explosives for Explosive Welding

    Science.gov (United States)

    Andreevskikh, Leonid

    2011-06-01

    Suggested and tested were some mix explosives--powder mixtures of a brisant high explosive (HE = RDX, PETN) and an inert diluent (baking soda)--for use in explosive welding. RDX and PETN were selected in view of their high throwing ability and low critical diameter. Since the decomposition of baking soda yields a huge amount of gaseous products, its presence ensures (even at a low HE percentage) a throwing speed that is sufficient for realization of explosive welding, at a reduced brisant action of charge. Mix chargers containing 30-70 wt % HE (the rest baking soda) have been tested experimentally and optimized. For study of possibility to reduce critical diameter of HE mixture, the mixture was prepared where HE crystal sizes did not exceed 10 μm. The tests, which were performed with this HE, revealed that the mixture detonated stably with the velocity D ~ 2 km/s, if the layer thickness was d = 2 mm. The above explosives afford to markedly diminish deformations within the oblique impact zone and thus to carry out explosive welding of hollow items and thin metallic foils.

  12. The effect of explosive percentage on underwater explosion energy release of hexanitrohexaazaisowurtzitane and octogen based aluminized explosives

    Directory of Open Access Journals (Sweden)

    Qingjie Jiao

    2018-03-01

    Full Text Available To control the explosion energy output by optimizing explosive components is a key requirement in a number of different application areas. The effect of different Al/O Ratio on underwater explosion of aluminized explosives has been studied detailedly. However, the effect of explosive percentage in the same Al/O Ratio is rarely researched, especially for Hexanitrohexaazaisowurtzitane (CL-20 based aluminized explosives. In this study, we performed the underwater explosion experiments with 1.2-kilogram explosives in order to investigate the explosion energy released from CL-20 and Octogen (HMX based aluminized explosives. The percentage of the explosive varied from 5% to 30% and it is shown that: the shockwave peak pressure (pm grows gradually; shock wave energy (Es continues increasing, bubble energy (Eb increases then decreases peaking at 15% for both formulas, and the total energy (E and energy release rate (η peak at 20% for CL-20 and 15% for HMX. This paper outlines the physical mechanism of Eb change under the influence of an aluminium initial reaction temperature and reaction active detonation product percentage coupling. The result shows that CL-20 is superior as a new high explosive and has promising application prospects in the regulation of explosive energy output for underwater explosives.

  13. The effect of explosive percentage on underwater explosion energy release of hexanitrohexaazaisowurtzitane and octogen based aluminized explosives

    Science.gov (United States)

    Jiao, Qingjie; Wang, Qiushi; Nie, Jianxin; Guo, Xueyong; Zhang, Wei; Fan, Wenqi

    2018-03-01

    To control the explosion energy output by optimizing explosive components is a key requirement in a number of different application areas. The effect of different Al/O Ratio on underwater explosion of aluminized explosives has been studied detailedly. However, the effect of explosive percentage in the same Al/O Ratio is rarely researched, especially for Hexanitrohexaazaisowurtzitane (CL-20) based aluminized explosives. In this study, we performed the underwater explosion experiments with 1.2-kilogram explosives in order to investigate the explosion energy released from CL-20 and Octogen (HMX) based aluminized explosives. The percentage of the explosive varied from 5% to 30% and it is shown that: the shockwave peak pressure (pm) grows gradually; shock wave energy (Es) continues increasing, bubble energy (Eb) increases then decreases peaking at 15% for both formulas, and the total energy (E) and energy release rate (η) peak at 20% for CL-20 and 15% for HMX. This paper outlines the physical mechanism of Eb change under the influence of an aluminium initial reaction temperature and reaction active detonation product percentage coupling. The result shows that CL-20 is superior as a new high explosive and has promising application prospects in the regulation of explosive energy output for underwater explosives.

  14. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Science.gov (United States)

    2013-10-28

    ..., including non-cap sensitive slurry and water gel explosives. Blasting caps. Blasting gelatin. Blasting.... Explosive conitrates. Explosive gelatins. Explosive liquids. Explosive mixtures containing oxygen-releasing... powder. [[Page 64247

  15. Adiabatic approximation with exponential accuracy for many-body systems and quantum computation

    International Nuclear Information System (INIS)

    Lidar, Daniel A.; Rezakhani, Ali T.; Hamma, Alioscia

    2009-01-01

    We derive a version of the adiabatic theorem that is especially suited for applications in adiabatic quantum computation, where it is reasonable to assume that the adiabatic interpolation between the initial and final Hamiltonians is controllable. Assuming that the Hamiltonian is analytic in a finite strip around the real-time axis, that some number of its time derivatives vanish at the initial and final times, and that the target adiabatic eigenstate is nondegenerate and separated by a gap from the rest of the spectrum, we show that one can obtain an error between the final adiabatic eigenstate and the actual time-evolved state which is exponentially small in the evolution time, where this time itself scales as the square of the norm of the time derivative of the Hamiltonian divided by the cube of the minimal gap.

  16. The effect of explosive percentage on underwater explosion energy release of hexanitrohexaazaisowurtzitane and octogen based aluminized explosives

    OpenAIRE

    Qingjie Jiao; Qiushi Wang; Jianxin Nie; Xueyong Guo; Wei Zhang; Wenqi Fan

    2018-01-01

    To control the explosion energy output by optimizing explosive components is a key requirement in a number of different application areas. The effect of different Al/O Ratio on underwater explosion of aluminized explosives has been studied detailedly. However, the effect of explosive percentage in the same Al/O Ratio is rarely researched, especially for Hexanitrohexaazaisowurtzitane (CL-20) based aluminized explosives. In this study, we performed the underwater explosion experiments with 1.2-...

  17. Adiabatic Quantum Computing

    Science.gov (United States)

    Landahl, Andrew

    2012-10-01

    Quantum computers promise to exploit counterintuitive quantum physics principles like superposition, entanglement, and uncertainty to solve problems using fundamentally fewer steps than any conventional computer ever could. The mere possibility of such a device has sharpened our understanding of quantum coherent information, just as lasers did for our understanding of coherent light. The chief obstacle to developing quantum computer technology is decoherence--one of the fastest phenomena in all of physics. In principle, decoherence can be overcome by using clever entangled redundancies in a process called fault-tolerant quantum error correction. However, the quality and scale of technology required to realize this solution appears distant. An exciting alternative is a proposal called ``adiabatic'' quantum computing (AQC), in which adiabatic quantum physics keeps the computer in its lowest-energy configuration throughout its operation, rendering it immune to many decoherence sources. The Adiabatic Quantum Architectures In Ultracold Systems (AQUARIUS) Grand Challenge Project at Sandia seeks to demonstrate this robustness in the laboratory and point a path forward for future hardware development. We are building devices in AQUARIUS that realize the AQC architecture on up to three quantum bits (``qubits'') in two platforms: Cs atoms laser-cooled to below 5 microkelvin and Si quantum dots cryo-cooled to below 100 millikelvin. We are also expanding theoretical frontiers by developing methods for scalable universal AQC in these platforms. We have successfully demonstrated operational qubits in both platforms and have even run modest one-qubit calculations using our Cs device. In the course of reaching our primary proof-of-principle demonstrations, we have developed multiple spinoff technologies including nanofabricated diffractive optical elements that define optical-tweezer trap arrays and atomic-scale Si lithography commensurate with placing individual donor atoms with

  18. Pulsed adiabatic structure and complete population transfer

    International Nuclear Information System (INIS)

    Shore, B.W.

    1992-10-01

    Population can be transferred between atomic or molecular energy states in a variety of ways. The basic idea of adiabatic transfer, discussed in many textbooks, is as follows. One begins with an atom that is in some single energy state (an eigenstate of an initial Hamiltonian). This energy state is one of many possible states, known variously as the unperturbed states or basis states or diabatic states. Next one begins to change the Hamiltonian very slowly. The changes may occur in either the diagonal elements (the basis state energies) or in the off-diagonal elements (interactions between basis states). If there are off-diagonal elements then the Hamiltonian will no longer commute with the original one. Because the Hamiltonian is no longer the one that was used to define the original basis states, it will cause these states to become mixed. However, if the change is sufficiently slow, the system can remain in a single eigenstate of the changing Hamiltonian -- an adiabatic state, composed of a combination of basis states. Finally, at some later time, one examines the system once again in the original basis. One finds that the population has undergone a change, and now resides in a different unperturbed state. One has produced population transfer. There are many illustrative examples of adiabatic passage, both theory and experiment. The author mentions briefly two common examples, inelastic collisions between atoms, and the static Stark effect in Rydberg atoms, before continuing with the main objective, a discussion of adiabatic passage induced by laser pulses

  19. Interpolation approach to Hamiltonian-varying quantum systems and the adiabatic theorem

    International Nuclear Information System (INIS)

    Pan, Yu; James, Matthew R.; Miao, Zibo; Amini, Nina H.; Ugrinovskii, Valery

    2015-01-01

    Quantum control could be implemented by varying the system Hamiltonian. According to adiabatic theorem, a slowly changing Hamiltonian can approximately keep the system at the ground state during the evolution if the initial state is a ground state. In this paper we consider this process as an interpolation between the initial and final Hamiltonians. We use the mean value of a single operator to measure the distance between the final state and the ideal ground state. This measure resembles the excitation energy or excess work performed in thermodynamics, which can be taken as the error of adiabatic approximation. We prove that under certain conditions, this error can be estimated for an arbitrarily given interpolating function. This error estimation could be used as guideline to induce adiabatic evolution. According to our calculation, the adiabatic approximation error is not linearly proportional to the average speed of the variation of the system Hamiltonian and the inverse of the energy gaps in many cases. In particular, we apply this analysis to an example in which the applicability of the adiabatic theorem is questionable. (orig.)

  20. Maritime improvised explosive devices, modelling and large scale trials

    NARCIS (Netherlands)

    Heuvel, W. van den; Trouwborst, W.; Vader, J.A.A.

    2013-01-01

    Maritime Improvised Explosive Devices (MIEDs) such as small boats filled with explosives are likely to be a threat in future combat scenarios. For example the suicide attack against the USS Cole in Yemen (October 2000) has shown how disastrous MIEDs can be. With relatively simple means a complete

  1. Non-adiabatic generator-coordinate calculation of H2+

    International Nuclear Information System (INIS)

    Tostes, J.G.R.; Para Univ., Belem; Toledo Piza, A.F.R. de

    1982-10-01

    A non-adiabatic calculation of the few lowest J=O states in the H 2+ molecule done within the framework of the Generator Coordinate Method is reported. Substantial accuracy is achivied with the diagonalization of matrices of very modest dimensions. The resulting wavefunctions are strongly dominated by just a few basis states. The computational scheme is set up so as to take the best advantage of good analytical approximations to existing adiabatic molecular wavefunctions. (Author) [pt

  2. Adiabatic supernova expansion into the circumstellar medium

    International Nuclear Information System (INIS)

    Band, D.L.; Liang, E.P.

    1987-01-01

    We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs

  3. A model for the interfacial shear in vertical, adiabatic, annular-mist flow

    International Nuclear Information System (INIS)

    Cappiello, M.W.

    1992-01-01

    A model is developed for the interfacial shear in upward, vertical, adiabatic, annular-mist flow. The model accounts for the momentum of both the droplet and film components and is applicable to the two-fluid approximation. Three computer programs are developed to evaluate the sensitivity of the droplet drag coefficient on the droplet velocity calculation, to solve the two-fluid set of equations by iteration, and to evaluate the required film friction factor from the data. The results of the sensitivity calculation show that a constant drag coefficient of 0.44 for the droplet is sufficient for estimating the droplet velocity over a typical range of gas velocities. Several film friction factor correlations from the literature were tested against the existing data of Hossfeld and Barathan. It was found that a modified effective roughness correlation proposed by Wallis performs the best overall in predicting the data for both small- and large-diameter pipes. The Electrical Power Research Institute drift-flux correlation and the Barathan correlation consistently underpredict the data. The use of the Henstock and Hanratty correlation predicts an incorrect trend. A new correlation is developed that better predicts the data over the entire range of gas injection rates. 17 refs

  4. Semiclassical modelling of finite-pulse effects on non-adiabatic photodynamics via initial condition filtering: The predissociation of NaI as a test case

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Mesa, Aliezer [Departmento de Física Teórica, Universidad de la Habana, San Lázaro y L, La Habana 10400 (Cuba); Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm (Germany); Saalfrank, Peter [Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm (Germany)

    2015-05-21

    Femtosecond-laser pulse driven non-adiabatic spectroscopy and dynamics in molecular and condensed phase systems continue to be a challenge for theoretical modelling. One of the main obstacles is the “curse of dimensionality” encountered in non-adiabatic, exact wavepacket propagation. A possible route towards treating complex molecular systems is via semiclassical surface-hopping schemes, in particular if they account not only for non-adiabatic post-excitation dynamics but also for the initial optical excitation. One such approach, based on initial condition filtering, will be put forward in what follows. As a simple test case which can be compared with exact wavepacket dynamics, we investigate the influence of the different parameters determining the shape of a laser pulse (e.g., its finite width and a possible chirp) on the predissociation dynamics of a NaI molecule, upon photoexcitation of the A(0{sup +}) state. The finite-pulse effects are mapped into the initial conditions for semiclassical surface-hopping simulations. The simulated surface-hopping diabatic populations are in qualitative agreement with the quantum mechanical results, especially concerning the subpicosend photoinduced dynamics, the main deviations being the relative delay of the non-adiabatic transitions in the semiclassical picture. Likewise, these differences in the time-dependent electronic populations calculated via the semiclassical and the quantum methods are found to have a mild influence on the overall probability density distribution. As a result, the branching ratios between the bound and the dissociative reaction channels and the time-evolution of the molecular wavepacket predicted by the semiclassical method agree with those computed using quantum wavepacket propagation. Implications for more challenging molecular systems are given.

  5. Diffusion Monte Carlo approach versus adiabatic computation for local Hamiltonians

    Science.gov (United States)

    Bringewatt, Jacob; Dorland, William; Jordan, Stephen P.; Mink, Alan

    2018-02-01

    Most research regarding quantum adiabatic optimization has focused on stoquastic Hamiltonians, whose ground states can be expressed with only real non-negative amplitudes and thus for whom destructive interference is not manifest. This raises the question of whether classical Monte Carlo algorithms can efficiently simulate quantum adiabatic optimization with stoquastic Hamiltonians. Recent results have given counterexamples in which path-integral and diffusion Monte Carlo fail to do so. However, most adiabatic optimization algorithms, such as for solving MAX-k -SAT problems, use k -local Hamiltonians, whereas our previous counterexample for diffusion Monte Carlo involved n -body interactions. Here we present a 6-local counterexample which demonstrates that even for these local Hamiltonians there are cases where diffusion Monte Carlo cannot efficiently simulate quantum adiabatic optimization. Furthermore, we perform empirical testing of diffusion Monte Carlo on a standard well-studied class of permutation-symmetric tunneling problems and similarly find large advantages for quantum optimization over diffusion Monte Carlo.

  6. Silicon Burning. II. Quasi-Equilibrium and Explosive Burning

    International Nuclear Information System (INIS)

    Hix, W.R.; Thielemann, F.

    1999-01-01

    Having examined the application of quasi-equilibrium to hydrostatic silicon burning in Paper I of this series, we now turn our attention to explosive silicon burning. Previous authors have shown that for material that is heated to high temperature by a passing shock and then cooled by adiabatic expansion, the results can be divided into three broad categories, incomplete burning, normal freezeout, and α-rich freezeout, with the outcome depending on the temperature, density, and cooling timescale. In all three cases, we find that the important abundances obey quasi-equilibrium for temperatures greater than approximately 3x10 9 K, with relatively little nucleosynthesis occurring following the breakdown of quasi-equilibrium. We will show that quasi-equilibrium provides better abundance estimates than global nuclear statistical equilibrium, even for normal freezeout, and particularly for α-rich freezeout. We will also examine the accuracy with which the final nuclear abundances can be estimated from quasi-equilibrium. copyright copyright 1999. The American Astronomical Society

  7. Hydrodynamic modeling and explosive compaction of ceramics

    International Nuclear Information System (INIS)

    Hoenig, C.; Holt, A.; Finger, M.; Kuhl, W.

    1977-01-01

    High-density ceramics with high-strength microstructure were achieved by explosive compaction. Well-characterized Al 2 O 3 , AlN, and boron powders were explosively compacted in both cylindrical and flat plate geometries. In cylindrical geometries compacted densities between 91 and 98 percent of theoretical were achieved. Microhardness measurements indicated that the strength and integrity of the microstructure were comparable to conventionally fabricated ceramics, even though all samples with densities greater than 90 percent theoretical contained macrocracks. Fractured surfaces evaluated by SEM showed evidence of boundary melting. Equation of state data for porous Al 2 O 3 were used to calculate the irreversible work done on the sample as a function of pressure. This was expressed as a percentage of the total sample which could be melted. Calculations show that very little melting can be expected in samples shocked to less than 3 GPa. Significant melting and grain boundary fusion can be expected in samples shocked to pressures greater than 8 GPa. Hydrodynamic modeling of right cylinder compaction with detonation at one end was attempted by using a two-dimensional computer code. The complications of this analysis led to experiments using plane shock waves. Flat-plate compaction assemblies were designed and analyzed by 2-D hydrodynamic codes. The use of porous shock attenuators was evaluated. Experiments were performed on aluminum oxide powders in plane wave geometry. Microstructure evaluations were made as a function of location in the flat plate samples. 11 figures, 1 table

  8. Alignment, orientation, and Coulomb explosion of difluoroiodobenzene studied with the pixel imaging mass spectrometry (PImMS) camera.

    Science.gov (United States)

    Amini, Kasra; Boll, Rebecca; Lauer, Alexandra; Burt, Michael; Lee, Jason W L; Christensen, Lauge; Brauβe, Felix; Mullins, Terence; Savelyev, Evgeny; Ablikim, Utuq; Berrah, Nora; Bomme, Cédric; Düsterer, Stefan; Erk, Benjamin; Höppner, Hauke; Johnsson, Per; Kierspel, Thomas; Krecinic, Faruk; Küpper, Jochen; Müller, Maria; Müller, Erland; Redlin, Harald; Rouzée, Arnaud; Schirmel, Nora; Thøgersen, Jan; Techert, Simone; Toleikis, Sven; Treusch, Rolf; Trippel, Sebastian; Ulmer, Anatoli; Wiese, Joss; Vallance, Claire; Rudenko, Artem; Stapelfeldt, Henrik; Brouard, Mark; Rolles, Daniel

    2017-07-07

    Laser-induced adiabatic alignment and mixed-field orientation of 2,6-difluoroiodobenzene (C 6 H 3 F 2 I) molecules are probed by Coulomb explosion imaging following either near-infrared strong-field ionization or extreme-ultraviolet multi-photon inner-shell ionization using free-electron laser pulses. The resulting photoelectrons and fragment ions are captured by a double-sided velocity map imaging spectrometer and projected onto two position-sensitive detectors. The ion side of the spectrometer is equipped with a pixel imaging mass spectrometry camera, a time-stamping pixelated detector that can record the hit positions and arrival times of up to four ions per pixel per acquisition cycle. Thus, the time-of-flight trace and ion momentum distributions for all fragments can be recorded simultaneously. We show that we can obtain a high degree of one-and three-dimensional alignment and mixed-field orientation and compare the Coulomb explosion process induced at both wavelengths.

  9. Estimating the size of the cavity and surrounding failed region for underground nuclear explosions from scaling rules

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Leo A [El Paso Natural Gas Company (United States)

    1970-05-01

    The fundamental physical principles involved in the formation of an underground cavity by a nuclear explosion and breakage of the rock surrounding the cavity are examined from the point of view of making preliminary estimates of their sizes where there is a limited understanding of the rock characteristics. Scaling equations for cavity formation based on adiabatic expansion are reviewed and further developed to include the strength of the material surrounding the shot point as well as the overburden above the shot point. The region of rock breakage or permanent distortion surround ing the explosion generated cavity is estimated using both the Von Mises and Coulomb-Mohr failure criteria. It is found that the ratio of the rock failure radius to the cavity radius for these two criteria becomes independent of yield and dependent only on the failure mechanics of the rock. The analytical solutions developed for the Coulomb-Mohr and Von Mises criteria are presented in graphical form. (author)

  10. Ramsey numbers and adiabatic quantum computing.

    Science.gov (United States)

    Gaitan, Frank; Clark, Lane

    2012-01-06

    The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n) with m, n≥3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n). We show how the computation of R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5≤s≤7. We then discuss the algorithm's experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class quantum Merlin Arthur.

  11. Probing Entanglement in Adiabatic Quantum Optimization with Trapped Ions

    Directory of Open Access Journals (Sweden)

    Philipp eHauke

    2015-04-01

    Full Text Available Adiabatic quantum optimization has been proposed as a route to solve NP-complete problems, with a possible quantum speedup compared to classical algorithms. However, the precise role of quantum effects, such as entanglement, in these optimization protocols is still unclear. We propose a setup of cold trapped ions that allows one to quantitatively characterize, in a controlled experiment, the interplay of entanglement, decoherence, and non-adiabaticity in adiabatic quantum optimization. We show that, in this way, a broad class of NP-complete problems becomes accessible for quantum simulations, including the knapsack problem, number partitioning, and instances of the max-cut problem. Moreover, a general theoretical study reveals correlations of the success probability with entanglement at the end of the protocol. From exact numerical simulations for small systems and linear ramps, however, we find no substantial correlations with the entanglement during the optimization. For the final state, we derive analytically a universal upper bound for the success probability as a function of entanglement, which can be measured in experiment. The proposed trapped-ion setups and the presented study of entanglement address pertinent questions of adiabatic quantum optimization, which may be of general interest across experimental platforms.

  12. Vulcanian explosions at Volcán de Colima, Mexico: modelling the conduit processes

    Science.gov (United States)

    Varley, N. R.; Stevenson, J.; Johnson, J.; Reyes, G.; Weber, K.; Sanderson, R.

    2006-12-01

    Activity at Volcán de Colima has increased over the past 8 years, and is possibly building towards a significant eruption. Monitoring its current activity is therefore critical, with recent expansion of the network providing new types of data which need to be understood. Recent activity has consisted of 3 effusive episodes lasting up to 22 months, separated by periods characterised by daily Vulcanian eruptions of small to moderate size; the largest producing pyroclastic flows reaching over 5 km, representing the most significant since the last Plinian event (1913). A model has been proposed to explain the mechanism of the Vulcanian explosions, derived through integrating different data including seismicity, SO2 flux and the ascent velocity and thermal emission of the eruption column. Infrasound measurements have helped to demonstrate the variability in the distribution of energy produced by the events. Swarms of low frequency seismic events were associated with the largest magnitude explosions and have been examined statistically with variations observed in the magnitude-frequency relationship of each swarm and their distribution. Seismic evidence of migration of the source has been identified, maybe explained by brittle fracturing associated with an increasing pressure differential within the conduit system. Volcán de Colima has a complex edifice structure with explosions switching between multiple vents and showing pulsing. Variation in remotely monitored fumarole temperatures has also been related to the explosive activity. It is clear that small variations of certain critical factors within the conduit system can lead to a transition between effusive and explosive activity. Frequent transitions at Volcán de Colima provide an ideal opportunity to analyse variations in the observable signals and deduce relationships with changes within the conduit that influence magma ascent and degassing, such as its volatile contents or ascent velocity. One goal of this

  13. Use of Kazakh nuclear explosions for testing dilatancy diffusion model of earthquake prediction

    International Nuclear Information System (INIS)

    Srivastava, H.N.

    1979-01-01

    P wave travel time anomalies from Kazakh explosions during the years 1965-1972 were studied with reference to Jeffreys Bullen (1952) and Herrin Travel time tables (1968) and discussed using F ratio test at seven stations in Himachal Pradesh. For these events, the temporal and spatial variations of travel time residuals were examined from the point of view of long term changes in velocity known to precede earthquakes and local geology. The results show perference for Herrin Travel time tables at these epicentral distances from Kazakh explosions. F ratio test indicated that variation between sample means of different stations in the network showed more variation than can be attributed to the sampling error. Although the spatial variation of mean residuals (1965-1972) could generally be explained on the basis of the local geology, the temporal variations of such residuals from Kazakh explosions offer limited application in the testing of dilatancy model of earthquake prediction. (auth.)

  14. Calorimetric studies and lessons on fires and explosions of a chemical plant producing CHP and DCPO

    International Nuclear Information System (INIS)

    Hsu, Jing-Ming; Su, Mao-Sheng; Huang, Chiao-Ying; Duh, Yih-Shing

    2012-01-01

    Highlights: ► We analyzed fire and explosion incidents in a plant producing CHP and DCPO. ► Data from calorimeters reveal causes and phenomena associated with the incidents. ► The credible worst scenario was thermal explosion. ► Incidents may be avoided by implementing DIERS methodology. - Abstract: Cumene hydroperoxide (CHP) has been used in producing phenol, dicumyl peroxide (DCPO) and as an initiator for synthesizing acrylonitrile–butadiene–styrene (ABS) resin by copolymerization in Taiwan. Four incidents of fire and explosion induced by thermal runaway reactions were occurred in a same plant producing CHP, DCPO and bis-(tert-butylperoxy isopropyl) benzene peroxide (BIBP). The fourth fire and explosion occurred in the CHP reactor that resulted in a catastrophic damage in reaction region and even spread throughout storage area. Descriptions on the occurrences of these incidents were assessed by the features of processes, reaction schemes and unexpected side reactions. Calorimetric data on thermokinetics and pressure were used for explaining the practical consequences or which the worst cases encountered in this kind of plant. Acceptable risk associated with emergency relief system design is vital for a plant producing organic peroxide. These basic data for designing an inherently safer plant can be conducted from adiabatic calorimetry. An encouraging deduction has been drawn here, these incidents may be avoided by the implementation of API RP 520, API RP 521, DIERS technology, OSHA 1910.119 and AIChE's CCPS recommended PSM elements.

  15. Description and validation of ERAD: An atmospheric dispersion model for high explosive detonations

    Energy Technology Data Exchange (ETDEWEB)

    Boughton, B.A.; DeLaurentis, J.M.

    1992-10-01

    The Explosive Release Atmospheric Dispersion (ERAD) model is a three-dimensional numerical simulation of turbulent atmospheric transport and diffusion. An integral plume rise technique is used to provide a description of the physical and thermodynamic properties of the cloud of warm gases formed when the explosive detonates. Particle dispersion is treated as a stochastic process which is simulated using a discrete time Lagrangian Monte Carlo method. The stochastic process approach permits a more fundamental treatment of buoyancy effects, calm winds and spatial variations in meteorological conditions. Computational requirements of the three-dimensional simulation are substantially reduced by using a conceptualization in which each Monte Carlo particle represents a small puff that spreads according to a Gaussian law in the horizontal directions. ERAD was evaluated against dosage and deposition measurements obtained during Operation Roller Coaster. The predicted contour areas average within about 50% of the observations. The validation results confirm the model`s representation of the physical processes.

  16. Chaotic jumps in the generalized first adiabatic invariant in current sheets

    International Nuclear Information System (INIS)

    Brittnacher, M.J.; Whipple, E.C.

    1991-01-01

    In attempting to develop a fluidlike model of plasma dynamics in a current sheet, kinetic effects due to chaotic non-adiabatic particle motion must be included in any realistic description. Using drift variables, derived by the Kruskal averaging procedure, to construct distribution functions may provide an approach in which to develop the fluid description. However, the drift motion is influenced by abrupt changes in the value of the generalized first adiabatic invariant J. In this letter, the authors indicate how the changes in J derived from separatrix crossing theory can be incorporated into the drift variable approach to generating distribution functions. In particular, the authors propose a method to determine distribution functions for an ensemble of particles following interactions with the tail current sheet by treating the interaction as a scattering problem characterized by changes in the invariant

  17. A note on the geometric phase in adiabatic approximation

    International Nuclear Information System (INIS)

    Tong, D.M.; Singh, K.; Kwek, L.C.; Fan, X.J.; Oh, C.H.

    2005-01-01

    The adiabatic theorem shows that the instantaneous eigenstate is a good approximation of the exact solution for a quantum system in adiabatic evolution. One may therefore expect that the geometric phase calculated by using the eigenstate should be also a good approximation of exact geometric phase. However, we find that the former phase may differ appreciably from the latter if the evolution time is large enough

  18. Explosions and light curves of supernovae

    International Nuclear Information System (INIS)

    Gaffet, B.

    1975-01-01

    The models developed to explain supernovae explosions are reviewed. The first one is thermonuclear explosion (simple or preceded by an implosion phase); the neutrino emission which results of such an explosion can have an important dynamical effect, according as the star is opaque or transparent to them; another theory involves the radiation pressure of the pulsar which is formed in the center of the star. The origin of the supernovae brightness is also uncertain: the initial heat due to the explosion does not seem to be sufficient; the brightness can result from the diffusion of the heat through the ejected matter or can be transported more rapidly by a shock wave. A model in which the heat is produced by the pulsar seems compatible with most observations (shapes of the brightness curves and the continuum spectra, expansion velocities, temperature and luminosity at the peak, total kinetic energy) [fr

  19. The effects of the Boussinesq model to the rising of the explosion clouds

    International Nuclear Information System (INIS)

    Li Xiaoli; Zheng Yi

    2010-01-01

    It is to study the rising of the explosion clouds in the normal atmosphere using Boussinesq model and the Incompressible model, the numerical model is based on the assumption that effects the clouds are gravity and buoyancy. By comparing the evolvement of different density cloud, and gives the conclusion-the Boussinesq model and the Incompressible model is accord when the cloud's density is larger compared to the density of the environment. (authors)

  20. An introduction to the adiabatic time-dependent Hartree-Fock method

    International Nuclear Information System (INIS)

    Giannoni, M.J.

    1984-05-01

    The aim of the adiabatic time-dependent Hartree-Fock method is to investigate the microscopic foundations of the phenomenological collective models. We briefly review the general formulation, which consists in deriving a Bohr-like Hamiltonian from a mean field theory, and discuss the limiting case where only a few collective variables participate to the motion. Some applications to soft nuclei and heavy ion collisions are presented

  1. Non-adiabatic study of the Kepler subgiant KIC 6442183

    Directory of Open Access Journals (Sweden)

    Grosjean M.

    2015-01-01

    Full Text Available Thanks to the precision of Kepler observations, [3] were able to measure the linewidth and amplitude of individual modes (including mixed modes in several subgiant power spectra. We perform a forward modelling of a Kepler subgiant based on surface properties and observed frequencies. Non-adiabatic computations including a time- dependent treatment of convection give the lifetimes of radial and non-radial modes. Next, combining the lifetimes and inertias with a stochastic excitation model gives the amplitudes of the modes. We can now directly compare theoretical and observed linewidths and amplitudes of mixed-modes to obtain new constraints on our theoretical models.

  2. Primary explosives

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Robert; Pachman, Jiri [Pardubice Univ. (Czech Republic). Faculty of Chemical Technology

    2013-06-01

    The first chapter provides background such as the basics of initiation and differences between requirements on primary explosives used in detonators and igniters. The authors then clarify the influence of physical characteristics on explosive properties, focusing on those properties required for primary explosives. Furthermore, the issue of sensitivity is discussed. All the chapters on particular groups of primary explosives are structured in the same way, including introduction, physical and chemical properties, explosive properties, preparation and documented use.

  3. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Anderson, R.P.; Armstrong, D.R.

    1977-01-01

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  4. An Adiabatic Phase-Matching Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lemery, Francois [DESY; Floettmann, Klaus [DESY; Piot, Philippe [Northern Illinois U.; Kaertner, Franz X. [Hamburg U.; Assmann, Ralph [DESY

    2017-12-22

    We present a general concept to accelerate non-relativistic charged particles. Our concept employs an adiabatically-tapered dielectric-lined waveguide which supports accelerating phase velocities for synchronous acceleration. We propose an ansatz for the transient field equations, show it satisfies Maxwell's equations under an adiabatic approximation and find excellent agreement with a finite-difference time-domain computer simulation. The fields were implemented into the particle-tracking program {\\sc astra} and we present beam dynamics results for an accelerating field with a 1-mm-wavelength and peak electric field of 100~MV/m. The numerical simulations indicate that a $\\sim 200$-keV electron beam can be accelerated to an energy of $\\sim10$~MeV over $\\sim 10$~cm. The novel scheme is also found to form electron beams with parameters of interest to a wide range of applications including, e.g., future advanced accelerators, and ultra-fast electron diffraction.

  5. Adiabatic quantum pumping and charge quantization

    International Nuclear Information System (INIS)

    Kashcheyevs, V; Aharony, A.; Entin-Wohlmanl, O.

    2004-01-01

    Full Text:Modern techniques for coherent manipulation of electrons at the nano scale (electrostatic gating, surface acoustic waves) allow for studies of the adiabatic quantum pumping effect - a directed current induced by a slowly varying external perturbation. Scattering theory of pumping predicts transfer of an almost integer number of electrons per cycle if instantaneous transmission is determined by a sequence of resonances. We show that this quantization can be explained in terms of loading/unloading quasi-bound virtual states, and derive a tool for analyzing quantized pumping induced by a general potential. This theory is applied to a simple model of pumping due to surface acoustic waves. The results reproduce all the qualitative features observed in actual experiments

  6. Calculation of the energy of explosives with a partial reaction model. Comparison with cylinder test data

    Energy Technology Data Exchange (ETDEWEB)

    Sanchidrian, Jose A.; Lopez, Lina M. [Universidad Politecnica de Madrid - E.T.S.I. Minas, Rios Rosas 21, E-28003 Madrid (Spain)

    2006-02-15

    The energy delivered by explosives is described by means of the useful expansion work along the isentrope of the detonation products. A thermodynamic code (W-DETCOM) is used, in which a partial reaction model has been implemented. In this model, the reacted fraction of the explosive in the detonation state is used as a fitting factor so that the calculated detonation velocity meets the experimental value. Calculations based on such a model have been carried out for a number of commercial explosives of ANFO and emulsion types. The BKW (Becker-Kistiakowsky-Wilson) equation of state is used for the detonation gases with the Sandia parameter set (BKWS). The energy delivered in the expansion (useful work) is calculated, and the values obtained are compared with the Gurney energies from cylinder test data at various expansion ratios. The expansion work values obtained are much more realistic than those from an ideal detonation calculation and, in most cases, the values predicted by the calculation are in good agreement with the experimental ones. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  7. Adiabatic transfer of energy fluctuations between membranes inside an optical cavity

    Science.gov (United States)

    Garg, Devender; Chauhan, Anil K.; Biswas, Asoka

    2017-08-01

    A scheme is presented for the adiabatic transfer of average fluctuations in the phonon number between two membranes in an optical cavity. We show that by driving the cavity modes with external time-delayed pulses, one can obtain an effect analogous to stimulated Raman adiabatic passage in the atomic systems. The adiabatic transfer of fluctuations from one membrane to the other is attained through a "dark" mode, which is robust against decay of the mediating cavity mode. The results are supported with analytical and numerical calculations with experimentally feasible parameters.

  8. Adiabatic time-dependent Hartree-Fock theory of collective motion in finite systems

    International Nuclear Information System (INIS)

    Baranger, M.; Veneroni, M.

    1978-01-01

    We show how to derive the parameters of a phenomenological collective model from a microscopic theory. The microscopic theory is Hartree-Fock, and we start from the time-dependent Hartree-Fock equation. To this we add the adiabatic approximation, which results in a collective kinetic energy quadratic in the velocities, with coefficients depending on the coordinates, as in the phenomenological models. The crucial step is the decomposition of the single-particle density matrix p in the form exp(i/sub chi/) rho/sub omicron/exp(-i/sub chi/), where rho/sub omicron/ represents a time-even Slater determinant and plays the role of coordinate. Then chi plays the role of momentum, and the adiabatic assumption is that chi is small. The energy is expanded in powers of chi, the zeroth-order being the collective potential energy. The analogy with classical mechanics is stressed and studied. The same adiabatic equations of motion are derived in three different ways (directly, from the Lagrangian, from the Hamiltonian), thus proving the consistency of the theory. The dynamical equation is not necessary for writing the energy or for the subsequent quantization which leads to a Schroedinger equation, but it must be used to check the validity of various approximation schemes, particularly to reduce the problem to a few degrees of freedom. The role of the adiabatic hypothesis, its definition, and range of validity, are analyzed in great detail. It assumes slow motion, but not small amplitude, and is therefore suitable for large-amplitude collective motion. The RPA is obtained as the limiting case where the amplitude is also small. The translational mass is correctly given, and the moment of inertia under rotation is that of Thouless and Valatin. For a quadrupole two-body force, the Baranger-Kumar formalism is recovered. The self-consistency brings additional terms to the Inglis cranking formula. Comparison is also made with generator coordinate methods

  9. Convergence of hyperspherical adiabatic expansion for helium-like systems

    International Nuclear Information System (INIS)

    Abrashkevich, A.G.; Abrashkevich, D.G.; Pojda, V.Yu.; Vinitskij, S.I.; Kaschiev, M.S.; Puzynin, I.V.

    1988-01-01

    The convergence of hyperspherical adiabatic expansion has been studied numerically. The spectral problems arising after separation of variables are solved by the finite-difference and finite element methods. The energies of the ground and some doubly excited staes of a hydrogen ion are calculated in the six-channel approximation within the 10 -4 a.u. accuracy. Obtained results demonstrate a rapid convergence of the hyperspherical adiabatic expansion. 14 refs.; 5 tabs

  10. Workshop on explosions, BLEVEs, fires, etc.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The purpose of this workshop will be to provide a bridge between engineering practices, modeling, and measurement of fires and explosions, and use this information in a practical manner to improve the fire safety of the process facility. New techniques and information are available on the means to prevent, predict and mitigate fires and explosions. A review of BLEVEs and methods for preventing and protecting against the effects of BLEVES in large petrochemical facilities. Observations and the use of models that have been successful in predicting the effects of vapor explosions for the prevention of collapse of structures and mitigation of the effects of vapor explosions in process facilities are presented. Recent work involving the measurement of radiation from large jet fires at the Kuwaiti oil fields and fire tests of crude oil spills on the sea is discussed. Fire radiation measurement can be used to predict effects on structures, facilities, and the complexity of fire fighting operations required for control of spill and pool fires. Practical applications of techniques for prevention and control of explosions within building, resulting from failures of autoclaves or release of flammable gas to the atmosphere of the building are discussed.

  11. Kinetic Theory Derivation of the Adiabatic Law for Ideal Gases.

    Science.gov (United States)

    Sobel, Michael I.

    1980-01-01

    Discusses how the adiabatic law for ideal gases can be derived from the assumption of a Maxwell-Boltzmann (or any other) distribution of velocities--in contrast to the usual derivations from thermodynamics alone, and the higher-order effect that leads to one-body viscosity. An elementary derivation of the adiabatic law is given. (Author/DS)

  12. Digitized adiabatic quantum computing with a superconducting circuit.

    Science.gov (United States)

    Barends, R; Shabani, A; Lamata, L; Kelly, J; Mezzacapo, A; Las Heras, U; Babbush, R; Fowler, A G; Campbell, B; Chen, Yu; Chen, Z; Chiaro, B; Dunsworth, A; Jeffrey, E; Lucero, E; Megrant, A; Mutus, J Y; Neeley, M; Neill, C; O'Malley, P J J; Quintana, C; Roushan, P; Sank, D; Vainsencher, A; Wenner, J; White, T C; Solano, E; Neven, H; Martinis, John M

    2016-06-09

    Quantum mechanics can help to solve complex problems in physics and chemistry, provided they can be programmed in a physical device. In adiabatic quantum computing, a system is slowly evolved from the ground state of a simple initial Hamiltonian to a final Hamiltonian that encodes a computational problem. The appeal of this approach lies in the combination of simplicity and generality; in principle, any problem can be encoded. In practice, applications are restricted by limited connectivity, available interactions and noise. A complementary approach is digital quantum computing, which enables the construction of arbitrary interactions and is compatible with error correction, but uses quantum circuit algorithms that are problem-specific. Here we combine the advantages of both approaches by implementing digitized adiabatic quantum computing in a superconducting system. We tomographically probe the system during the digitized evolution and explore the scaling of errors with system size. We then let the full system find the solution to random instances of the one-dimensional Ising problem as well as problem Hamiltonians that involve more complex interactions. This digital quantum simulation of the adiabatic algorithm consists of up to nine qubits and up to 1,000 quantum logic gates. The demonstration of digitized adiabatic quantum computing in the solid state opens a path to synthesizing long-range correlations and solving complex computational problems. When combined with fault-tolerance, our approach becomes a general-purpose algorithm that is scalable.

  13. Toward Improved Fidelity of Thermal Explosion Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, A L; Becker, R; Howard, W M; Wemhoff, A

    2009-07-17

    We will present results of an effort to improve the thermal/chemical/mechanical modeling of HMX based explosive like LX04 and LX10 for thermal cook-off. The original HMX model and analysis scheme were developed by Yoh et.al. for use in the ALE3D modeling framework. The current results were built to remedy the deficiencies of that original model. We concentrated our efforts in four areas. The first area was addition of porosity to the chemical material model framework in ALE3D that is used to model the HMX explosive formulation. This is needed to handle the roughly 2% porosity in solid explosives. The second area was the improvement of the HMX reaction network, which included the inclusion of a reactive phase change model base on work by Henson et.al. The third area required adding early decomposition gas species to the CHEETAH material database to develop more accurate equations of state for gaseous intermediates and products. Finally, it was necessary to improve the implicit mechanics module in ALE3D to more naturally handle the long time scales associated with thermal cook-off. The application of the resulting framework to the analysis of the Scaled Thermal Explosion (STEX) experiments will be discussed.

  14. Assessment of Safety Parameters for Radiological Explosion Based on Gaussian Dispersion Model

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Alok [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yu, Hyungjoon; Kim, Hong Suk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-10-15

    These sources if used with explosive (called RDD - radiological dispersion device), can cause dispersion of radioactive material resulting in public exposure and contamination of the environment. Radiological explosion devices are not weapons for the mass destruction like atom bombs, but can cause the death of few persons and contamination of large areas. The reduction of the threat of radiological weapon attack by terrorist groups causing dispersion of radioactive material is one of the priority tasks of the IAEA Nuclear Safety and Security Program.Emergency preparedness is an essential part for reducing and mitigating radiological weapon threat. Preliminary assessment of dispersion study followed by radiological explosion and its quantitative effect will be helpful for the emergency preparedness team for an early response. The effect of the radiological dispersion depends on various factors like radioisotope, its activity, physical form, amount of explosive used and meteorological factors at the time of an explosion. This study aim to determine the area affected by the radiological explosion as pre assessment to provide feedback to emergency management teams for handling and mitigation the situation after an explosion. Most practical scenarios of radiological explosion are considered with conservative approach for the assessment of the area under a threat for emergency handling and management purpose. Radioisotopes under weak security controls can be used for a radiological explosion to create terror and socioeconomic threat for the public. Prior assessment of radiological threats is helpful for emergency management teams to take prompt decision about evacuation of the affected area and other emergency handling actions. Comparable activities of Co-60 source used in radiotherapy and Sr-90 source of disused and orphaned RTGs with two different quantities of TNT were used for the scenario development of radiological explosion. In the Basic Safety Standard (BSS

  15. Assessment of Safety Parameters for Radiological Explosion Based on Gaussian Dispersion Model

    International Nuclear Information System (INIS)

    Pandey, Alok; Yu, Hyungjoon; Kim, Hong Suk

    2014-01-01

    These sources if used with explosive (called RDD - radiological dispersion device), can cause dispersion of radioactive material resulting in public exposure and contamination of the environment. Radiological explosion devices are not weapons for the mass destruction like atom bombs, but can cause the death of few persons and contamination of large areas. The reduction of the threat of radiological weapon attack by terrorist groups causing dispersion of radioactive material is one of the priority tasks of the IAEA Nuclear Safety and Security Program.Emergency preparedness is an essential part for reducing and mitigating radiological weapon threat. Preliminary assessment of dispersion study followed by radiological explosion and its quantitative effect will be helpful for the emergency preparedness team for an early response. The effect of the radiological dispersion depends on various factors like radioisotope, its activity, physical form, amount of explosive used and meteorological factors at the time of an explosion. This study aim to determine the area affected by the radiological explosion as pre assessment to provide feedback to emergency management teams for handling and mitigation the situation after an explosion. Most practical scenarios of radiological explosion are considered with conservative approach for the assessment of the area under a threat for emergency handling and management purpose. Radioisotopes under weak security controls can be used for a radiological explosion to create terror and socioeconomic threat for the public. Prior assessment of radiological threats is helpful for emergency management teams to take prompt decision about evacuation of the affected area and other emergency handling actions. Comparable activities of Co-60 source used in radiotherapy and Sr-90 source of disused and orphaned RTGs with two different quantities of TNT were used for the scenario development of radiological explosion. In the Basic Safety Standard (BSS

  16. High Resolution Digital Elevation Models of Pristine Explosion Craters

    Science.gov (United States)

    Farr, T. G.; Krabill, W.; Garvin, J. B.

    2004-01-01

    In order to effectively capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained high resolution digital elevation models of several pristine explosion craters at the Nevada Test Site. We used the Airborne Terrain Mapper (ATM), operated by NASA's Wallops Flight Facility to obtain DEMs with 1 m spacing and 10 cm vertical errors of 4 main craters and many other craters and collapse pits. The main craters that were mapped are Sedan, Scooter, Schooner, and Danny Boy. The 370 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of a controlled detonation of a 100 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a simple crater. Sedan was formed in alluvium of mixed lithology and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also mapped by ATM. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m) craters were also important targets for ATM as they were excavated in hard basalt and therefore have much rougher ejecta. This will allow study of ejecta patterns in hard rock as well as engineering tests of crater and rock avoidance and rover trafficability. In addition to the high resolution DEMs, crater geometric characteristics, RMS roughness maps, and other higher-order derived data products will be generated using these data. These will provide constraints for models of landing hazards on Mars and for rover trafficability. Other planned studies will include ejecta size-frequency distribution at the resolution of the DEM and at finer resolution through air photography and field measurements

  17. Explosion-Induced Implosions of Cylindrical Shell Structures

    Science.gov (United States)

    Ikeda, C. M.; Duncan, J. H.

    2010-11-01

    An experimental study of the explosion-induced implosion of cylindrical shell structures in a high-pressure water environment was performed. The shell structures are filled with air at atmospheric pressure and are placed in a large water-filled pressure vessel. The vessel is then pressurized to various levels P∞=αPc, where Pc is the natural implosion pressure of the model and α is a factor that ranges from 0.1 to 0.9. An explosive is then set off at various standoff distances, d, from the model center line, where d varies from R to 10R and R is the maximum radius of the explosion bubble. High-speed photography (27,000 fps) was used to observe the explosion and resulting shell structure implosion. High-frequency underwater blast sensors recorded dynamic pressure waves at 6 positions. The cylindrical models were made from aluminum (diameter D = 39.1 mm, wall thickness t = 0.89 mm, length L = 240 mm) and brass (D = 16.7 mm, t = 0.36 mm, L=152 mm) tubes. The pressure records are interpreted in light of the high-speed movies. It is found that the implosion is induced by two mechanisms: the shockwave generated by the explosion and the jet formed during the explosion-bubble collapse. Whether an implosion is caused by the shockwave or the jet depends on the maximum bubble diameter and the standoff distance.

  18. The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Soker, Noam, E-mail: soker@physics.technion.ac.il [Department of Physics, Technion—Israel Institute of Technology, Haifa 32000 (Israel)

    2017-04-10

    Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is ( E {sub NS-spin}/ E {sub exp}) ≈ E {sub exp}/10{sup 52} erg; It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.

  19. Adiabatic perturbation theory in quantum dynamics

    CERN Document Server

    Teufel, Stefan

    2003-01-01

    Separation of scales plays a fundamental role in the understanding of the dynamical behaviour of complex systems in physics and other natural sciences. A prominent example is the Born-Oppenheimer approximation in molecular dynamics. This book focuses on a recent approach to adiabatic perturbation theory, which emphasizes the role of effective equations of motion and the separation of the adiabatic limit from the semiclassical limit. A detailed introduction gives an overview of the subject and makes the later chapters accessible also to readers less familiar with the material. Although the general mathematical theory based on pseudodifferential calculus is presented in detail, there is an emphasis on concrete and relevant examples from physics. Applications range from molecular dynamics to the dynamics of electrons in a crystal and from the quantum mechanics of partially confined systems to Dirac particles and nonrelativistic QED.

  20. A MEASUREMENT OF THE ADIABATIC COOLING INDEX FOR INTERSTELLAR HELIUM PICKUP IONS IN THE INNER HELIOSPHERE

    International Nuclear Information System (INIS)

    Saul, Lukas; Wurz, Peter; Kallenbach, Reinald

    2009-01-01

    Interstellar neutral gas enters the inner heliosphere where it is ionized and becomes the pickup ion population of the solar wind. It is often assumed that this population will subsequently cool adiabatically, like an expanding ideal gas due, to the divergent flow of the solar wind. Here, we report the first independent measure of the effective adiabatic cooling index in the inner heliosphere from SOHO CELIAS measurements of singly charged helium taken during times of perpendicular interplanetary magnetic field. We use a simple adiabatic transport model of interstellar pickup helium ions, valid for the upwind region of the inner heliosphere. The time averaged velocity spectrum of helium pickup ions measured by CELIAS/CTOF is fit to this model with a single free parameter which indicates an effective cooling rate with a power-law index of γ = 1.35 ± 0.2. While this average is consistent with the 'ideal-gas' assumption of γ = 1.5, the analysis indicates that such an assumption will not apply in general, and that due to observational constraints further measurements are necessary to constrain the cooling process. Implications are discussed for understanding the transport processes in the inner heliosphere and improving this measurement technique.

  1. Compact beam splitters in coupled waveguides using shortcuts to adiabaticity

    Science.gov (United States)

    Chen, Xi; Wen, Rui-Dan; Shi, Jie-Long; Tseng, Shuo-Yen

    2018-04-01

    There are various works on adiabatic (three) waveguide coupler devices but most are focused on the quantum optical analogies and the physics itself. We successfully apply shortcuts to adiabaticity techniques to the coupled waveguide system with a suitable length for integrated optics devices. Especially, the counter-diabatic driving protocol followed by unitary transformation overcomes the previously unrealistic implemention, and is used to design feasible and robust 1 × 2 and 1 × 3 beam splitters for symmetric and asymmetric three waveguide couplers. Numerical simulations with the beam propagation method demonstrate that these shortcut designs for beam splitters are shorter than the adiabatic ones, and also have a better tolerance than parallel waveguides resonant beam splitters with respect to spacing errors and wavelength variation.

  2. Adiabatic Expansion of Electron Gas in a Magnetic Nozzle

    Science.gov (United States)

    Takahashi, Kazunori; Charles, Christine; Boswell, Rod; Ando, Akira

    2018-01-01

    A specially constructed experiment shows the near perfect adiabatic expansion of an ideal electron gas resulting in a polytropic index greater than 1.4, approaching the adiabatic value of 5 /3 , when removing electric fields from the system, while the polytropic index close to unity is observed when the electrons are trapped by the electric fields. The measurements were made on collisionless electrons in an argon plasma expanding in a magnetic nozzle. The collision lengths of all electron collision processes are greater than the scale length of the expansion, meaning the system cannot be in thermodynamic equilibrium, yet thermodynamic concepts can be used, with caution, in explaining the results. In particular, a Lorentz force, created by inhomogeneities in the radial plasma density, does work on the expanding magnetic field, reducing the internal energy of the electron gas that behaves as an adiabatically expanding ideal gas.

  3. The adiabatic approximation in multichannel scattering

    International Nuclear Information System (INIS)

    Schulte, A.M.

    1978-01-01

    Using two-dimensional models, an attempt has been made to get an impression of the conditions of validity of the adiabatic approximation. For a nucleon bound to a rotating nucleus the Coriolis coupling is neglected and the relation between this nuclear Coriolis coupling and the classical Coriolis force has been examined. The approximation for particle scattering from an axially symmetric rotating nucleus based on a short duration of the collision, has been combined with an approximation based on the limitation of angular momentum transfer between particle and nucleus. Numerical calculations demonstrate the validity of the new combined method. The concept of time duration for quantum mechanical collisions has also been studied, as has the collective description of permanently deformed nuclei. (C.F.)

  4. Non-adiabatic molecular dynamics with complex quantum trajectories. I. The diabatic representation.

    Science.gov (United States)

    Zamstein, Noa; Tannor, David J

    2012-12-14

    We extend a recently developed quantum trajectory method [Y. Goldfarb, I. Degani, and D. J. Tannor, J. Chem. Phys. 125, 231103 (2006)] to treat non-adiabatic transitions. Each trajectory evolves on a single surface according to Newton's laws with complex positions and momenta. The transfer of amplitude between surfaces stems naturally from the equations of motion, without the need for surface hopping. In this paper we derive the equations of motion and show results in the diabatic representation, which is rarely used in trajectory methods for calculating non-adiabatic dynamics. We apply our method to the first two benchmark models introduced by Tully [J. Chem. Phys. 93, 1061 (1990)]. Besides giving the probability branching ratios between the surfaces, the method also allows the reconstruction of the time-dependent wavepacket. Our results are in quantitative agreement with converged quantum mechanical calculations.

  5. Study and modelling of the escalation phase of a steam explosion

    International Nuclear Information System (INIS)

    Leclerc, Eric

    2000-01-01

    In Severe Accident studies for PWR, large amount of molten corium may be poured into water. There is then a risk of Steam Explosion. After the premixing sequence in which the melt is more or less dispersed into water, a fine fragmentation process may start which can lead to an escalation. Such an event is generally triggered by the destabilization of the vapour film surrounding the hot melt droplets. In this thesis, an attempt to describe all the successive processes leading to this fine fragmentation is presented. First a critical analysis of previous models is performed, allowing to propose a new sequence of events. As in the previous models, the film destabilization leads to the growth of cold liquids peaks induced by Rayleigh Taylor instability. As these peaks have a smaller density than the drop, they do not penetrate into the hot drop. At the cold liquid-hot liquid contacts, transient heat transfer leads to the explosive boiling of a small amount of coolant. The generated local pressurization deform the hot melt interface. This can produce fine fragments from the filaments issued from the melt. Some of them may reach the vapour-coolant interface where intense and rapid vaporization occurs. A large bubble then develops and a new fragmentation sequence may again appear at the bubble collapse. The present model is support by experimental results. (author) [fr

  6. Failure of geometric electromagnetism in the adiabatic vector Kepler problem

    International Nuclear Information System (INIS)

    Anglin, J.R.; Schmiedmayer, J.

    2004-01-01

    The magnetic moment of a particle orbiting a straight current-carrying wire may precess rapidly enough in the wire's magnetic field to justify an adiabatic approximation, eliminating the rapid time dependence of the magnetic moment and leaving only the particle position as a slow degree of freedom. To zeroth order in the adiabatic expansion, the orbits of the particle in the plane perpendicular to the wire are Keplerian ellipses. Higher-order postadiabatic corrections make the orbits precess, but recent analysis of this 'vector Kepler problem' has shown that the effective Hamiltonian incorporating a postadiabatic scalar potential ('geometric electromagnetism') fails to predict the precession correctly, while a heuristic alternative succeeds. In this paper we resolve the apparent failure of the postadiabatic approximation, by pointing out that the correct second-order analysis produces a third Hamiltonian, in which geometric electromagnetism is supplemented by a tensor potential. The heuristic Hamiltonian of Schmiedmayer and Scrinzi is then shown to be a canonical transformation of the correct adiabatic Hamiltonian, to second order. The transformation has the important advantage of removing a 1/r 3 singularity which is an artifact of the adiabatic approximation

  7. Calorimetric studies and lessons on fires and explosions of a chemical plant producing CHP and DCPO

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Jing-Ming; Su, Mao-Sheng; Huang, Chiao-Ying [Department of Occupational Safety and Health, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, ROC (China); Duh, Yih-Shing, E-mail: yihshingduh@yahoo.com.tw [Department of Safety, Health and Environmental Engineering, National United University, No. 1 Lien-Da, Miaoli, Taiwan, ROC (China)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer We analyzed fire and explosion incidents in a plant producing CHP and DCPO. Black-Right-Pointing-Pointer Data from calorimeters reveal causes and phenomena associated with the incidents. Black-Right-Pointing-Pointer The credible worst scenario was thermal explosion. Black-Right-Pointing-Pointer Incidents may be avoided by implementing DIERS methodology. - Abstract: Cumene hydroperoxide (CHP) has been used in producing phenol, dicumyl peroxide (DCPO) and as an initiator for synthesizing acrylonitrile-butadiene-styrene (ABS) resin by copolymerization in Taiwan. Four incidents of fire and explosion induced by thermal runaway reactions were occurred in a same plant producing CHP, DCPO and bis-(tert-butylperoxy isopropyl) benzene peroxide (BIBP). The fourth fire and explosion occurred in the CHP reactor that resulted in a catastrophic damage in reaction region and even spread throughout storage area. Descriptions on the occurrences of these incidents were assessed by the features of processes, reaction schemes and unexpected side reactions. Calorimetric data on thermokinetics and pressure were used for explaining the practical consequences or which the worst cases encountered in this kind of plant. Acceptable risk associated with emergency relief system design is vital for a plant producing organic peroxide. These basic data for designing an inherently safer plant can be conducted from adiabatic calorimetry. An encouraging deduction has been drawn here, these incidents may be avoided by the implementation of API RP 520, API RP 521, DIERS technology, OSHA 1910.119 and AIChE's CCPS recommended PSM elements.

  8. Quantification of the effect of hysteresis on the adiabatic temperature change in magnetocaloric materials

    DEFF Research Database (Denmark)

    von Moos, Lars; Bahl, Christian R.H.; Nielsen, Kaspar Kirstein

    2014-01-01

    description of the phase transition at varying magnetic fields and temperatures. Using detailed experimental property data, a Preisach type model is used to describe the thermal hysteresis effects and simulate the material under realistic working conditions. We find that the adiabatic temperature change...

  9. Gas explosion in domestic buildings. The vented gas explosion[sub][/sub

    Directory of Open Access Journals (Sweden)

    Tadeusz Chyży

    2014-08-01

    Full Text Available In this paper, the basic information, related to the so-called vented gas explosion, has been presented. The vented explosion it is an explosion, during which the destruction of the weakest elements of the structure occurs. Through the resulting holes (decompressing surfaces can flow both combustion products and non-burned gas mixture. In consequence, reduction of the maximum explosion pressure[i] P[sub]red [/sub][/i] may be significant. Often, a gas explosion occurs inside residential buildings. In this case, natural vents are window and door openings.[b]Keywords[/b]: gas, explosion, combustion, explosion vents

  10. Sensitivity of inertial confinement fusion hot spot properties to the deuterium-tritium fuel adiabat

    Energy Technology Data Exchange (ETDEWEB)

    Melvin, J.; Lim, H.; Rana, V.; Glimm, J. [Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794-3600 (United States); Cheng, B.; Sharp, D. H.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2015-02-15

    We determine the dependence of key Inertial Confinement Fusion (ICF) hot spot simulation properties on the deuterium-tritium fuel adiabat, here modified by addition of energy to the cold shell. Variation of this parameter reduces the simulation to experiment discrepancy in some, but not all, experimentally inferred quantities. Using simulations with radiation drives tuned to match experimental shots N120321 and N120405 from the National Ignition Campaign (NIC), we carry out sets of simulations with varying amounts of added entropy and examine the sensitivities of important experimental quantities. Neutron yields, burn widths, hot spot densities, and pressures follow a trend approaching their experimentally inferred quantities. Ion temperatures and areal densities are sensitive to the adiabat changes, but do not necessarily converge to their experimental quantities with the added entropy. This suggests that a modification to the simulation adiabat is one of, but not the only explanation of the observed simulation to experiment discrepancies. In addition, we use a theoretical model to predict 3D mix and observe a slight trend toward less mixing as the entropy is enhanced. Instantaneous quantities are assessed at the time of maximum neutron production, determined dynamically within each simulation. These trends contribute to ICF science, as an effort to understand the NIC simulation to experiment discrepancy, and in their relation to the high foot experiments, which features a higher adiabat in the experimental design and an improved neutron yield in the experimental results.

  11. Sensitivity of inertial confinement fusion hot spot properties to the deuterium-tritium fuel adiabat

    International Nuclear Information System (INIS)

    Melvin, J.; Lim, H.; Rana, V.; Glimm, J.; Cheng, B.; Sharp, D. H.; Wilson, D. C.

    2015-01-01

    We determine the dependence of key Inertial Confinement Fusion (ICF) hot spot simulation properties on the deuterium-tritium fuel adiabat, here modified by addition of energy to the cold shell. Variation of this parameter reduces the simulation to experiment discrepancy in some, but not all, experimentally inferred quantities. Using simulations with radiation drives tuned to match experimental shots N120321 and N120405 from the National Ignition Campaign (NIC), we carry out sets of simulations with varying amounts of added entropy and examine the sensitivities of important experimental quantities. Neutron yields, burn widths, hot spot densities, and pressures follow a trend approaching their experimentally inferred quantities. Ion temperatures and areal densities are sensitive to the adiabat changes, but do not necessarily converge to their experimental quantities with the added entropy. This suggests that a modification to the simulation adiabat is one of, but not the only explanation of the observed simulation to experiment discrepancies. In addition, we use a theoretical model to predict 3D mix and observe a slight trend toward less mixing as the entropy is enhanced. Instantaneous quantities are assessed at the time of maximum neutron production, determined dynamically within each simulation. These trends contribute to ICF science, as an effort to understand the NIC simulation to experiment discrepancy, and in their relation to the high foot experiments, which features a higher adiabat in the experimental design and an improved neutron yield in the experimental results

  12. Sensitivity of inertial confinement fusion hot spot properties to the deuterium-tritium fuel adiabat

    Science.gov (United States)

    Melvin, J.; Lim, H.; Rana, V.; Cheng, B.; Glimm, J.; Sharp, D. H.; Wilson, D. C.

    2015-02-01

    We determine the dependence of key Inertial Confinement Fusion (ICF) hot spot simulation properties on the deuterium-tritium fuel adiabat, here modified by addition of energy to the cold shell. Variation of this parameter reduces the simulation to experiment discrepancy in some, but not all, experimentally inferred quantities. Using simulations with radiation drives tuned to match experimental shots N120321 and N120405 from the National Ignition Campaign (NIC), we carry out sets of simulations with varying amounts of added entropy and examine the sensitivities of important experimental quantities. Neutron yields, burn widths, hot spot densities, and pressures follow a trend approaching their experimentally inferred quantities. Ion temperatures and areal densities are sensitive to the adiabat changes, but do not necessarily converge to their experimental quantities with the added entropy. This suggests that a modification to the simulation adiabat is one of, but not the only explanation of the observed simulation to experiment discrepancies. In addition, we use a theoretical model to predict 3D mix and observe a slight trend toward less mixing as the entropy is enhanced. Instantaneous quantities are assessed at the time of maximum neutron production, determined dynamically within each simulation. These trends contribute to ICF science, as an effort to understand the NIC simulation to experiment discrepancy, and in their relation to the high foot experiments, which features a higher adiabat in the experimental design and an improved neutron yield in the experimental results.

  13. 2D and 3D numerical modeling of seismic waves from explosion sources

    International Nuclear Information System (INIS)

    McLaughlin, K.L.; Stevens, J.L.; Barker, T.G.; Shkoller, B.; Day, S.M.

    1993-01-01

    Over the last decade, nonlinear and linear 2D axisymmetric finite difference codes have been used in conjunction with far-field seismic Green's functions to simulate seismic waves from a variety of sources. In this paper we briefly review some of the results and conclusions that have resulted from numerical simulations and explosion modeling in support of treaty verification research at S-CUBED in the last decade. We then describe in more detail the results from two recent projects. Our goal is to provide a flavor for the kinds of problems that can be examined with numerical methods for modeling excitation of seismic waves from explosions. Two classes of problems have been addressed; nonlinear and linear near-source interactions. In both classes of problems displacements and tractions are saved on a closed surface in the linear region and the representation theorem is used to propagate the seismic waves to the far-field

  14. Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field

    Directory of Open Access Journals (Sweden)

    T. J. Barton

    2012-12-01

    Full Text Available Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [K. R. Samokhvalova, J. Zhou, and C. Chen, Phys. Plasmas 14, 103102 (2007PHPAEN1070-664X10.1063/1.2779281; J. Zhou, K. R. Samokhvalova, and C. Chen, Phys. Plasmas 15, 023102 (2008PHPAEN1070-664X10.1063/1.2837891]. In particular, results are obtained for adiabatic thermal beams that do not rotate in the Larmor frame. For such beams, the theoretical predictions of the rms beam envelope, the conservations of the rms thermal emittances, the adiabatic equation of state, and the Debye length are verified in the simulations. Furthermore, the adiabatic thermal beam is found be stable in the parameter regime where the simulations are performed.

  15. Shallow magma diversions during explosive diatreme-forming eruptions.

    Science.gov (United States)

    Le Corvec, Nicolas; Muirhead, James D; White, James D L

    2018-04-13

    The diversion of magma is an important mechanism that may lead to the relocation of a volcanic vent. Magma diversion is known to occur during explosive volcanic eruptions generating subterranean excavation and remobilization of country and volcanic rocks. However, feedbacks between explosive crater formation and intrusion processes have not been considered previously, despite their importance for understanding evolving hazards during volcanic eruptions. Here, we apply numerical modeling to test the impacts of excavation and subsequent infilling of diatreme structures on stress states and intrusion geometries during the formation of maar-diatreme complexes. Explosive excavation and infilling of diatremes affects local stress states which inhibits magma ascent and drives lateral diversion at various depths, which are expected to promote intra-diatreme explosions, host rock mixing, and vent migration. Our models demonstrate novel mechanisms explaining the generation of saucer-shaped sills, linked with magma diversion and enhanced intra-diatreme explosive fragmentation during maar-diatreme volcanism. Similar mechanisms will occur at other volcanic vents producing crater-forming eruptions.

  16. Connection between optimal control theory and adiabatic-passage techniques in quantum systems

    Science.gov (United States)

    Assémat, E.; Sugny, D.

    2012-08-01

    This work explores the relationship between optimal control theory and adiabatic passage techniques in quantum systems. The study is based on a geometric analysis of the Hamiltonian dynamics constructed from Pontryagin's maximum principle. In a three-level quantum system, we show that the stimulated Raman adiabatic passage technique can be associated to a peculiar Hamiltonian singularity. One deduces that the adiabatic pulse is solution of the optimal control problem only for a specific cost functional. This analysis is extended to the case of a four-level quantum system.

  17. Change of adiabatic invariant near the separatrix

    International Nuclear Information System (INIS)

    Bulanov, S.V.

    1995-10-01

    The properties of particle motion in the vicinity of the separatrix in a phase plane are investigated. The change of adiabatic invariant value due to the separatrix crossing is evaluated as a function of a perturbation parameter magnitude and a phase of a particle for time dependent Hamiltonians. It is demonstrated that the change of adiabatic invariant value near the separatrix birth is much larger than that in the case of the separatrix crossing near the saddle point in a phase plane. The conditions of a stochastic regime to appear around the separatrix are found. The results are applied to study the longitudinal invariant behaviour of charged particles near singular lines of the magnetic field. (author). 22 refs, 9 figs

  18. Simulations and measurements of adiabatic annular flows in triangular, tight lattice nuclear fuel bundle model

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Abhishek, E-mail: asaxena@lke.mavt.ethz.ch [ETH Zurich, Laboratory for Nuclear Energy Systems, Department of Mechanical and Process Engineering, Sonneggstrasse 3, 8092 Zürich (Switzerland); Zboray, Robert [Laboratory for Thermal-hydraulics, Nuclear Energy and Safety Department, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Prasser, Horst-Michael [ETH Zurich, Laboratory for Nuclear Energy Systems, Department of Mechanical and Process Engineering, Sonneggstrasse 3, 8092 Zürich (Switzerland); Laboratory for Thermal-hydraulics, Nuclear Energy and Safety Department, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2016-04-01

    High conversion light water reactors (HCLWR) having triangular, tight-lattice fuels bundles could enable improved fuel utilization compared to present day LWRs. However, the efficient cooling of a tight lattice bundle has to be still proven. Major concern is the avoidance of high-quality boiling crisis (film dry-out) by the use of efficient functional spacers. For this reason, we have carried out experiments on adiabatic, air-water annular two-phase flows in a tight-lattice, triangular fuel bundle model using generic spacers. A high-spatial-resolution, non-intrusive measurement technology, cold neutron tomography, has been utilized to resolve the distribution of the liquid film thickness on the virtual fuel pin surfaces. Unsteady CFD simulations have also been performed to replicate and compare with the experiments using the commercial code STAR-CCM+. Large eddies have been resolved on the grid level to capture the dominant unsteady flow features expected to drive the liquid film thickness distribution downstream of a spacer while the subgrid scales have been modeled using the Wall Adapting Local Eddy (WALE) subgrid model. A Volume of Fluid (VOF) method, which directly tracks the interface and does away with closure relationship models for interfacial exchange terms, has also been employed. The present paper shows first comparison of the measurement with the simulation results.

  19. Regional moment: Magnitude relations for earthquakes and explosions

    Energy Technology Data Exchange (ETDEWEB)

    Patton, H.J.; Walter, W.R. (Lawrence Livermore National Lab., CA (United States))

    1993-02-19

    The authors present M[sub o]:m[sub b] relations using m[sub b](P[sub n]) and m[sub b](L[sub g]) for earthquakes and explosions occurring in tectonic and stable areas. The observations for m[sub b](P[sub n]) range from about 3 to 6 and show excellent separation between earthquakes and explosions on M[sub o]:m[sub b] plots, independent of the magnitude. The scatter in M[sub o]:M[sub b] observations for NTS explosions is small compared to the earthquake data. The M[sub o]:m[sub b](L[sub g]) data for Soviet explosions overlay the observations for US explosions. These results, and the small scatter for NTS explosions, suggest weak dependence of M[sub o]:m[sub b] relations on emplacement media. A simple theoretical model is developed which matches all these observations. The model uses scaling similarity and conservation of energy to provide a physical link between seismic moment and a broadband seismic magnitude. Three factors, radiation pattern, material property, and apparent stress, contribute to the separation between earthquakes and explosions. This theoretical separation is independent of broadband magnitude. For US explosions in different media, the material property and apparent stress contributions are shown to compensate for one another, supporting the observations that M[sub o]:M[sub b] is nearly independent of source geology. 19 refs., 2 figs., 1 tab.

  20. Surface-wave generation by underground nuclear explosions releasing tectonic strain

    International Nuclear Information System (INIS)

    Patton, H.J.

    1980-01-01

    Seismic surface-wave generation by underground nuclear explosions releasing tectonic strain is studied through a series of synthetic radiation-pattern calculations based on the earthquake-trigger model. From amplitude and phase radiation patterns for 20-s Rayleigh waves, inferences are made about effects on surface-wave magnitude, M/sub s/, and waveform character. The focus of this study is a comparison between two mechanisms of tectonic strain release: strike-slip motion on vertical faults and thrust motion on 45 0 dipping faults. The results of our calculations show that Rayleigh-wave amplitudes of the dip-slip model at F values between 0.75 and 1.5 are significantly lower than amplitudes of the strike-slip model or of the explosion source alone. This effect translates into M/sub s/ values about 0.5 units lower than M/sub s/ of the explosion alone. Waveform polarity reversals occur in two of four azimuthal quadrants for the strike-slip model and in all azimuths of the dip-slip-thrust model for F values above about 3. A cursory examination of waveforms from presumed explosions in eastern Kazakhstan suggests that releases of tectonic strain are accompanying the detonation of many of these explosions. Qualitatively, the observations seem to favor the dip-slip-thrust model, which, in the case of a few explosions, must have F values above 3

  1. Near-surface velocity modeling at Yucca Mountain using borehole and surface records from underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Durrani, B.A. [Texas Univ., El Paso, TX (United States). Dept. of Geological Sciences; Walck, M.C. [Sandia National Labs., Albuquerque, NM (United States)

    1996-09-01

    The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity model for the uppermost 350m of the mountain. This model is useful for prediction of repository-level ground motions for potential large nearby earthquakes.

  2. Near-surface velocity modeling at Yucca Mountain using borehole and surface records from underground nuclear explosions

    International Nuclear Information System (INIS)

    Durrani, B.A.

    1996-09-01

    The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity model for the uppermost 350m of the mountain. This model is useful for prediction of repository-level ground motions for potential large nearby earthquakes

  3. Mathematical modeling of seismic explosion waves impact on rock mass with a working

    Directory of Open Access Journals (Sweden)

    А. П. Господариков

    2017-08-01

    Full Text Available In the article, within the framework of the dynamic theory of elasticity, a mathematical model of the impact of seismic blast waves on rock mass is presented, including a working. The increase in the volume of mining operations in complex mining and geological conditions, taking into account the influence of the explosion energy, is closely connected with the analysis of the main parameters of the stress-strain state of the rock massif including a working. The latter leads to the need to determine the safe parameters of drilling and blasting operations that ensure the operational state of mining. The main danger in detonation of an explosive charge near an active working is a seismic explosive wave which characteristics are determined by the properties of soil and parameters of drilling and blasting operations. The determination of stress fields and displacement velocities in rock mass requires the use of a modern mathematical apparatus for its solution. For numerical solution of the given boundary value problem by the method of finite differences, an original calculation-difference scheme is constructed. The application of the splitting method for solving a two-dimensional boundary value problem is reduced to the solution of spatially one-dimensional differential equations. For the obtained numerical algorithm, an effective computational software has been developed. Numerical solutions of the model problem are given for the case when the shape of the working has a form of an ellipse.

  4. Non-Adiabatic Molecular Dynamics Methods for Materials Discovery

    Energy Technology Data Exchange (ETDEWEB)

    Furche, Filipp [Univ. of California, Irvine, CA (United States); Parker, Shane M. [Univ. of California, Irvine, CA (United States); Muuronen, Mikko J. [Univ. of California, Irvine, CA (United States); Roy, Saswata [Univ. of California, Irvine, CA (United States)

    2017-04-04

    The flow of radiative energy in light-driven materials such as photosensitizer dyes or photocatalysts is governed by non-adiabatic transitions between electronic states and cannot be described within the Born-Oppenheimer approximation commonly used in electronic structure theory. The non-adiabatic molecular dynamics (NAMD) methods based on Tully surface hopping and time-dependent density functional theory developed in this project have greatly extended the range of molecular materials that can be tackled by NAMD simulations. New algorithms to compute molecular excited state and response properties efficiently were developed. Fundamental limitations of common non-linear response methods were discovered and characterized. Methods for accurate computations of vibronic spectra of materials such as black absorbers were developed and applied. It was shown that open-shell TDDFT methods capture bond breaking in NAMD simulations, a longstanding challenge for single-reference molecular dynamics simulations. The methods developed in this project were applied to study the photodissociation of acetaldehyde and revealed that non-adiabatic effects are experimentally observable in fragment kinetic energy distributions. Finally, the project enabled the first detailed NAMD simulations of photocatalytic water oxidation by titania nanoclusters, uncovering the mechanism of this fundamentally important reaction for fuel generation and storage.

  5. Dimensional analysis of small-scale steam explosion experiments

    International Nuclear Information System (INIS)

    Huh, K.; Corradini, M.L.

    1986-01-01

    Dimensional analysis applied to Nelson's small-scale steam explosion experiments to determine the qualitative effect of each relevant parameter for triggering a steam explosion. According to experimental results, the liquid entrapment model seems to be a consistent explanation for the steam explosion triggering mechanism. The three-dimensional oscillatory wave motion of the vapor/liquid interface is analyzed to determine the necessary conditions for local condensation and production of a coolant microjet to be entrapped in fuel. It is proposed that different contact modes between fuel and coolant may involve different initiation mechanisms of steam explosions

  6. Geometry of quantal adiabatic evolution driven by a non-Hermitian Hamiltonian

    International Nuclear Information System (INIS)

    Wu Zhaoyan; Yu Ting; Zhou Hongwei

    1994-01-01

    It is shown by using a counter example, which is exactly solvable, that the quantal adiabatic theorem does not generally hold for a non-Hermitian driving Hamiltonian, even if it varies extremely slowly. The condition for the quantal adiabatic theorem to hold for non-Hermitian driving Hamiltonians is given. The adiabatic evolutions driven by a non-Hermitian Hamiltonian provide examples of a new geometric structure, that is the vector bundle in which the inner product of two parallelly transported vectors generally changes. A new geometric concept, the attenuation tensor, is naturally introduced to describe the decay or flourish of the open quantum system. It is constructed in terms of the spectral projector of the Hamiltonian. (orig.)

  7. Statistical estimation of loads from gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiset, Stian

    1998-12-31

    In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. The main uncertainties in computerized simulation of gas explosions are the assumptions of the gas cloud, the location of the ignition point and the properties of the simulator itself. This thesis quantifies the levels of these uncertainties by performing a large number of simulations on three offshore modules and one onshore plant. It is found that (1) there is an approximate linear relation between pressure and gas volume, (2) it may be possible to find a linear relation between pressure and impulse, (3) there is an inverse relation between pressure and duration, (4) the response of offshore structures exposed to gas explosions are rarely in the impulsive regime, (5) loading rates vary widely in magnitude, (6) an assumption of a triangular explosion pulse is often correct, (7) louvres increase pressure, impulse and duration of an explosion. The effect of ignition point location is studied in detail. It is possible to derive an ignition point uncertainty load factor that shows predictable behaviour by generalizing the non-parametric properties of the explosion pressure. A model for taking into account the uncertainties regarding gas volume, ignition point location and simulator imperfectness is proposed. The model is intended to produce a characteristic load for structural design. 68 refs., 51 figs., 36 tabs.

  8. The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism

    International Nuclear Information System (INIS)

    Soker, Noam

    2017-01-01

    Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is ( E _N_S_-_s_p_i_n/ E _e_x_p) ≈ E _e_x_p/10"5"2 erg; It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.

  9. Experimental and numerical studies of choked flow through adiabatic and diabatic capillary tubes

    International Nuclear Information System (INIS)

    Deodhar, Subodh D.; Kothadia, Hardik B.; Iyer, K.N.; Prabhu, S.V.

    2015-01-01

    Capillary tubes are extensively used in several cooling applications like refrigeration, electronic cooling etc. Local pressure variation in adiabatic straight capillary tube (mini channel) is studied experimentally and numerically with R134a as the working fluid. Experiments are performed on two straight capillary tubes. It is found that the diameter is the most sensitive design parameter of the capillary tube. Experiments are performed on five helically coiled capillary tubes to quantify the effect of pitch and curvature of helically coiled capillary tube on the pressure drop. Non dimensionalized factor to account coiling of capillary tube is derived to calculate mass flow rate in helically coiled capillary tubes. Flow visualization in adiabatic capillary tube confirms the bubbly nature of two phase flow. Numerical and experimental investigations in diabatic capillary tube suggest that the use of positive displacement pump and choking at the exit of the channel ensures flow stability. - Highlights: • Model is developed to design capillary tube in adiabatic and diabatic condition. • Effect of coil curvature on pressure drop is studied experimentally. • Correlation is developed to predict mass flow rate in helical capillary tubes. • Flow visualization is carried out to check the type of two phase flow. • Effect of choked flow on diabatic capillary tubes is studied experimentally.

  10. Source effects on surface waves from Nevada Test Site explosions

    International Nuclear Information System (INIS)

    Patton, H.J.; Vergino, E.S.

    1981-11-01

    Surface waves recorded on the Lawrence Livermore National Laboratory (LLNL) digital network have been used to study five underground nuclear explosions detonated in Yucca Valley at the Nevada Test Site. The purpose of this study is to characterize the reduced displacement potential (RDP) at low frequencies and to test secondary source models of underground explosions. The observations consist of Rayleigh- and Love-wave amplitude and phase spectra in the frequency range 0.03 to 0.16 Hz. We have found that Rayleigh-wave spectral amplitudes are modeled well by a RDP with little or no overshoot for explosions detonated in alluvium and tuff. On the basis of comparisons between observed and predicted source phase, the spall closure source proposed by Viecelli does not appear to be a significant source of Rayleigh waves that reach the far field. We tested two other secondary source models, the strike-slip, tectonic strain release model proposed by Toksoez and Kehrer and the dip-slip thrust model of Masse. The surface-wave observations do not provide sufficient information to discriminate between these models at the low F-values (0.2 to 0.8) obtained for these explosions. In the case of the strike-slip model, the principal stress axes inferred from the fault slip angle and strike angle are in good agreement with the regional tectonic stress field for all but one explosion, Nessel. The results of the Nessel explosion suggest a mechanism other than tectonic strain release

  11. Adiabatic flame temperature of sodium combustion and sodium-water reaction

    International Nuclear Information System (INIS)

    Okano, Y.; Yamaguchi, A.

    2001-01-01

    In this paper, background information of sodium fire and sodium-water reaction accidents of LMFBR (liquid metal fast breeder reactor) is mentioned at first. Next, numerical analysis method of GENESYS is described in detail. Next, adiabatic flame temperature and composition of sodium combustion are analyzed, and affect of reactant composition, such oxygen and moisture, is discussed. Finally, adiabatic reaction zone temperature and composition of sodium-water reaction are calculated, and affects of reactant composition, sodium vaporization, and pressure are stated. Chemical equilibrium calculation program for generic chemical system (GENESYS) is developed in this study for the research on adiabatic flame temperature of sodium combustion and adiabatic reaction zone temperature of sodium-water reaction. The maximum flame temperature of the sodium combustion is 1,950 K at the standard atmospheric condition, and is not affected by the existence of moisture. The main reaction product is Na 2 O (l) , and in combustion in moist air, with NaOH (g) . The maximum reaction zone temperature of the sodium-water reaction is 1,600 K, and increases with the system pressure. The main products are NaOH (g) , NaOH (l) and H2 (g) . Sodium evaporation should be considered in the cases of sodium-rich and high pressure above 10 bar

  12. General phenomenology of underground nuclear explosions; Phenomenologie generale des explosions nucleaires souterraines

    Energy Technology Data Exchange (ETDEWEB)

    Derlich, S; Supiot, F [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    An essentially qualitatively description is given of the phenomena related to underground nuclear explosions (explosion of a single unit, of several units in line, and simultaneous explosions). In the first chapter are described the phenomena which are common to contained explosions and to explosions forming craters (formation and propagation of a shock-wave causing the vaporization, the fusion and the fracturing of the medium). The second chapter describes the phenomena related to contained explosions (formation of a cavity with a chimney). The third chapter is devoted to the phenomenology of test explosions which form a crater; it describes in particular the mechanism of formation and the different types of craters as a function of the depth of the explosion and of the nature of the ground. The aerial phenomena connected with explosions which form a crater: shock wave in the air and focussing at a large distance, and dust clouds, are also dealt with. (authors) [French] On donne une description essentiellement qualitative des phenomenes lies aux explosions nucleaires souterraines (explosion d'un seul engin, d'engins en ligne et explosions simultanees). Dans un premier chapitre sont decrits les phenomenes communs aux explosions contenues et aux explosions formant un cratere (formation et propagation d'une onde de choc provoquant la vaporisation, la fusion et la fracturation du milieu). Le deuxieme chapitre decrit les phenomenes lies aux tirs contenus (formation d'une cavite et d'une cheminee). Le troisieme chapitre est consacre a la phenomenologie des tirs formant un cratere et decrit notamment le mecanisme de formation et les differents types de crateres en fonction de la profondeur d'explosion et de la nature du terrain. Les phenomenes aeriens lies aux explosions formant un cratere: onde de pression aerienne et focalisation a grande distance, nuages de poussieres, sont egalement abordes. (auteurs)

  13. Confronting Models of Massive Star Evolution and Explosions with Remnant Mass Measurements

    Science.gov (United States)

    Raithel, Carolyn A.; Sukhbold, Tuguldur; Özel, Feryal

    2018-03-01

    The mass distribution of compact objects provides a fossil record that can be studied to uncover information on the late stages of massive star evolution, the supernova explosion mechanism, and the dense matter equation of state. Observations of neutron star masses indicate a bimodal Gaussian distribution, while the observed black hole mass distribution decays exponentially for stellar-mass black holes. We use these observed distributions to directly confront the predictions of stellar evolution models and the neutrino-driven supernova simulations of Sukhbold et al. We find strong agreement between the black hole and low-mass neutron star distributions created by these simulations and the observations. We show that a large fraction of the stellar envelope must be ejected, either during the formation of stellar-mass black holes or prior to the implosion through tidal stripping due to a binary companion, in order to reproduce the observed black hole mass distribution. We also determine the origins of the bimodal peaks of the neutron star mass distribution, finding that the low-mass peak (centered at ∼1.4 M ⊙) originates from progenitors with M ZAMS ≈ 9–18 M ⊙. The simulations fail to reproduce the observed peak of high-mass neutron stars (centered at ∼1.8 M ⊙) and we explore several possible explanations. We argue that the close agreement between the observed and predicted black hole and low-mass neutron star mass distributions provides new, promising evidence that these stellar evolution and explosion models capture the majority of relevant stellar, nuclear, and explosion physics involved in the formation of compact objects.

  14. Asymmetric explosion of core-collapse supernovae

    International Nuclear Information System (INIS)

    Kazeroni, Remi

    2016-01-01

    A core-collapse supernova represents the ultimate stage of the evolution of massive stars.The iron core contraction may be followed by a gigantic explosion which gives birth to a neutron star.The multidimensional dynamics of the innermost region, during the first hundreds milliseconds, plays a decisive role on the explosion success because hydrodynamical instabilities are able to break the spherical symmetry of the collapse. Large scale transverse motions generated by two instabilities, the neutrino-driven convection and the Standing Accretion Shock Instability (SASI),increase the heating efficiency up to the point of launching an asymmetric explosion and influencing the birth properties of the neutron star. In this thesis, hydrodynamical instabilities are studied using numerical simulations of simplified models. These models enable a wide exploration of the parameter space and a better physical understanding of the instabilities, generally inaccessible to realistic models.The non-linear regime of SASI is analysed to characterize the conditions under which a spiral mode prevails and to assess its ability to redistribute angular momentum radially.The influence of rotation on the shock dynamics is also addressed. For fast enough rotation rates, a corotation instability overlaps with SASI and greatly impacts the dynamics. The simulations enable to better constrain the effect of non-axisymmetric modes on the angular momentum budget of the iron core collapsing into a neutron star. SASI may under specific conditions spin up or down the pulsar born during the explosion. Finally, an idealised model of the heating region is studied to characterize the non-linear onset of convection by perturbations such as those produced by SASI or pre-collapse combustion inhomogeneities. The dimensionality issue is examined to stress the beneficial consequences of the three-dimensional dynamics on the onset of the explosion. (author) [fr

  15. Adiabatic Theorem for Quantum Spin Systems

    Science.gov (United States)

    Bachmann, S.; De Roeck, W.; Fraas, M.

    2017-08-01

    The first proof of the quantum adiabatic theorem was given as early as 1928. Today, this theorem is increasingly applied in a many-body context, e.g., in quantum annealing and in studies of topological properties of matter. In this setup, the rate of variation ɛ of local terms is indeed small compared to the gap, but the rate of variation of the total, extensive Hamiltonian, is not. Therefore, applications to many-body systems are not covered by the proofs and arguments in the literature. In this Letter, we prove a version of the adiabatic theorem for gapped ground states of interacting quantum spin systems, under assumptions that remain valid in the thermodynamic limit. As an application, we give a mathematical proof of Kubo's linear response formula for a broad class of gapped interacting systems. We predict that the density of nonadiabatic excitations is exponentially small in the driving rate and the scaling of the exponent depends on the dimension.

  16. Microstructural Characteristics and Mechanical Properties of 2205/AZ31B Laminates Fabricated by Explosive Welding

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-04-01

    Full Text Available A bimetal composite of 2205 duplex stainless steel and AZ31B magnesium alloy was cladded successfully through the method of explosive welding. The microstructural characteristics and mechanical properties of 2205/AZ31B bimetal composite are discussed. The interface of 2205/AZ31B bimetallic composite was a less regular wavy morphology with locally melted pockets. Adiabatic shear bands occurred only in the AZ31B side near explosive welding interface. The microstructure observed with EBSD showed a strong refinement near the interface zones. Line scan confirmed that the interface had a short element diffusion zone which would contribute to the metallurgical bonding between 2205 duplex stainless steel and AZ31B magnesium alloy. The value of micro-hardness near the bonding interface of composite plate increased because of work hardening and grain refinement. The tensile shear strength of bonding interface of 2205/AZ31B composite was 105.63 MPa. Tensile strength of 2205/AZ31B composite material was higher than the base AZ31B. There were two abrupt drops in stress in the stress–strain curves of the 2205/AZ31B composite materials.

  17. Adiabatic invariance with first integrals of motion

    Science.gov (United States)

    Adib, Artur B.

    2002-10-01

    The construction of a microthermodynamic formalism for isolated systems based on the concept of adiabatic invariance is an old but seldom appreciated effort in the literature, dating back at least to P. Hertz [Ann. Phys. (Leipzig) 33, 225 (1910)]. An apparently independent extension of such formalism for systems bearing additional first integrals of motion was recently proposed by Hans H. Rugh [Phys. Rev. E 64, 055101 (2001)], establishing the concept of adiabatic invariance even in such singular cases. After some remarks in connection with the formalism pioneered by Hertz, it will be suggested that such an extension can incidentally explain the success of a dynamical method for computing the entropy of classical interacting fluids, at least in some potential applications where the presence of additional first integrals cannot be ignored.

  18. RFDR with Adiabatic Inversion Pulses: Application to Internuclear Distance Measurements

    International Nuclear Information System (INIS)

    Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

    2004-01-01

    In the context of the structural characterisation of biomolecular systems via MAS solid state NMR, the potential utility of homonuclear dipolar recoupling with adiabatic inversion pulses has been assessed via numerical simulations and experimental measurements. The results obtained suggest that it is possible to obtain reliable estimates of internuclear distances via an analysis of the initial cross-peak intensity buildup curves generated from two-dimensional adiabatic inversion pulse driven longitudinal magnetisation exchange experiments

  19. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

    Full Text Available The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.

  20. Explosive Leidenfrost droplets

    Science.gov (United States)

    Colinet, Pierre; Moreau, Florian; Dorbolo, Stéphane

    2017-11-01

    We show that Leidenfrost droplets made of an aqueous solution of surfactant undergo a violent explosion in a wide range of initial volumes and concentrations. This unexpected behavior turns out to be triggered by the formation of a gel-like shell, followed by a sharp temperature increase. Comparing a simple model of the radial surfactant distribution inside a spherical droplet with experiments allows highlighting the existence of a critical surface concentration for the shell to form. The temperature rise (attributed to boiling point elevation with surface concentration) is a key feature leading to the explosion, instead of the implosion (buckling) scenario reported by other authors. Indeed, under some conditions, this temperature increase is shown to be sufficient to trigger nucleation and growth of vapor bubbles in the highly superheated liquid bulk, stretching the surrounding elastic shell up to its rupture limit. The successive timescales characterizing this explosion sequence are also discussed. Funding sources: F.R.S. - FNRS (ODILE and DITRASOL projects, RD and SRA positions of P. Colinet and S. Dorbolo), BELSPO (IAP 7/38 MicroMAST project).

  1. Computer simulation of explosion crater in dams with different buried depths of explosive

    Science.gov (United States)

    Zhang, Zhichao; Ye, Longzhen

    2018-04-01

    Based on multi-material ALE method, this paper conducted a computer simulation on the explosion crater in dams with different buried depths of explosive using LS-DYNA program. The results turn out that the crater size increases with the increase of buried depth of explosive at first, but closed explosion cavity rather than a visible crater is formed when the buried depth of explosive increases to some extent. The soil in the explosion cavity is taken away by the explosion products and the soil under the explosion cavity is compressed with its density increased. The research can provide some reference for the anti-explosion design of dams in the future.

  2. ASYMPT - a program to calculate asymptotics of hyperspherical potential curves and adiabatic potentials

    International Nuclear Information System (INIS)

    Abrashkevich, A.G.; Puzynin, I.V.; Vinitskij, S.I.

    1997-01-01

    A FORTRAN 77 program is presented which calculates asymptotics of potential curves and adiabatic potentials with an accuracy of O(ρ -2 ) in the framework of the hyperspherical adiabatic (HSA) approach. It is shown that matrix elements of the equivalent operator corresponding to the perturbation ρ -2 have a simple form in the basis of the Coulomb parabolic functions in the body-fixed frame and can be easily computed for high values of total orbital momentum and threshold number. The second-order corrections to the adiabatic curves are obtained as the solutions of the corresponding secular equation. The asymptotic potentials obtained can be used for the calculation of the energy levels and radial wave functions of two-electron systems in the adiabatic and coupled-channel approximations of the HSA approach

  3. Thermal decomposition and reaction of confined explosives

    International Nuclear Information System (INIS)

    Catalano, E.; McGuire, R.; Lee, E.; Wrenn, E.; Ornellas, D.; Walton, J.

    1976-01-01

    Some new experiments designed to accurately determine the time interval required to produce a reactive event in confined explosives subjected to temperatures which will cause decomposition are described. Geometry and boundary conditions were both well defined so that these experiments on the rapid thermal decomposition of HE are amenable to predictive modelling. Experiments have been carried out on TNT, TATB and on two plastic-bonded HMX-based high explosives, LX-04 and LX-10. When the results of these experiments are plotted as the logarithm of the time to explosion versus 1/T K (Arrhenius plot), the curves produced are remarkably linear. This is in contradiction to the results obtained by an iterative solution of the Laplace equation for a system with a first order rate heat source. Such calculations produce plots which display considerable curvature. The experiments have also shown that the time to explosion is strongly influenced by the void volume in the containment vessel. Results of the experiments with calculations based on the heat flow equations coupled with first-order models of chemical decomposition are compared. The comparisons demonstrate the need for a more realistic reaction model

  4. Class and Home Problems. Modeling an Explosion: The Devil Is in the Details

    Science.gov (United States)

    Hart, Peter W.; Rudie, Alan W.

    2011-01-01

    Within the past 15 years, three North American pulp mills experienced catastrophic equipment failures while using 50 wt% hydrogen peroxide. In two cases, explosions occurred when normal pulp flow was interrupted due to other process problems. To understand the accidents, a kinetic model of alkali-catalyzed decomposition of peroxide was developed.…

  5. Adiabatic out-of-equilibrium solutions to the Boltzmann equation in warm inflation

    Science.gov (United States)

    Bastero-Gil, Mar; Berera, Arjun; Ramos, Rudnei O.; Rosa, João G.

    2018-02-01

    We show that, in warm inflation, the nearly constant Hubble rate and temperature lead to an adiabatic evolution of the number density of particles interacting with the thermal bath, even if thermal equilibrium cannot be maintained. In this case, the number density is suppressed compared to the equilibrium value but the associated phase-space distribution retains approximately an equilibrium form, with a smaller amplitude and a slightly smaller effective temperature. As an application, we explicitly construct a baryogenesis mechanism during warm inflation based on the out-of-equilibrium decay of particles in such an adiabatically evolving state. We show that this generically leads to small baryon isocurvature perturbations, within the bounds set by the Planck satellite. These are correlated with the main adiabatic curvature perturbations but exhibit a distinct spectral index, which may constitute a smoking gun for baryogenesis during warm inflation. Finally, we discuss the prospects for other applications of adiabatically evolving out-of-equilibrium states.

  6. Post-adiabatic analysis of atomic collisions

    International Nuclear Information System (INIS)

    Klar, H.; Fano, U.

    1976-01-01

    The coupling between adiabatic channels can be partially transformed away. The transformation need not induce any transition between channnels; but it correlates the radial wave functions and their gradients with the channel functions and it depresses the lower effective potentials, as the energy increases, in accordance with empirical evidence

  7. Effects of different aging statuses and strain rate on the adiabatic shear susceptibility of 2195 aluminum–lithium alloy

    International Nuclear Information System (INIS)

    Yang, Y.; Tan, G.Y.; Chen, P.X.; Zhang, Q.M.

    2012-01-01

    The adiabatic shear susceptibility of 2195 aluminum–lithium alloy was investigated by means of split Hopkinson pressure bar. The stress collapse in true stress–true strain curves and true stress–time curves was observed. The adiabatic shear susceptibility of different aging statuses and strain rate were discussed by means of metallography observation. The critical strain, stress collapse time and formation energy of adiabatic shear bands were compared. The results show that different aging statuses and strain rate have significant influences on adiabatic shear behaviors of 2195 aluminum–lithium alloy. The peak-aged specimen has the highest adiabatic shearing susceptibility, while the under-aged specimen has the least adiabatic shear susceptibility. The susceptibility of adiabatic shearing increases with the increases of strain rate.

  8. Effects of different aging statuses and strain rate on the adiabatic shear susceptibility of 2195 aluminum-lithium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); State Key Laboratory of Explosion Science and Technology, Beijing 100081 (China); Tan, G.Y., E-mail: yangyanggroup@163.com [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); Chen, P.X. [School of Materials Science and Engineering, Central South University, Changsha 410083, Hunan (China); Zhang, Q.M. [State Key Laboratory of Explosion Science and Technology, Beijing 100081 (China)

    2012-06-01

    The adiabatic shear susceptibility of 2195 aluminum-lithium alloy was investigated by means of split Hopkinson pressure bar. The stress collapse in true stress-true strain curves and true stress-time curves was observed. The adiabatic shear susceptibility of different aging statuses and strain rate were discussed by means of metallography observation. The critical strain, stress collapse time and formation energy of adiabatic shear bands were compared. The results show that different aging statuses and strain rate have significant influences on adiabatic shear behaviors of 2195 aluminum-lithium alloy. The peak-aged specimen has the highest adiabatic shearing susceptibility, while the under-aged specimen has the least adiabatic shear susceptibility. The susceptibility of adiabatic shearing increases with the increases of strain rate.

  9. Effects of Containment on Radionuclide Releases from Underground Nuclear Explosions

    Science.gov (United States)

    Carrigan, C. R.; Sun, Y.

    2016-12-01

    Confirming the occurrence of an underground nuclear explosion can require capturing short-lived noble gas radioisotopes produced by the explosion, sometimes referred to as the "smoking gun" for nuclear explosion detection. It is well known that the radioisotopic distribution resulting from the detonation evolves with time in the explosion cavity. In effect, the explosion cavity or chimney behaves as a chemical reactor. As long as the parent and daughter radionuclides remain in a closed and well-mixed cavity, parameters, such as radioxenon isotopic ratios, can be calculated analytically from a decay-chain network model. When gases from the cavity migrate into the containment regime, consideration of a "leaky reactor" model is more appropriate. We consider several implications of such a leaky reactor model relevant to interpretations of gas samples from the subsurface during an on-site inspection that could potentially be carried out under the Comprehensive Nuclear Test Ban Treaty. Additionally, we have attempted to validate our leaky reactor model against atmospheric observations of radioactive xenon isotopes detected by radionuclide monitoring stations in Japan and Russia following the February 2013 DPRK underground nuclear explosion (Carrigan et al., 2016). While both model uncertainty and observational error are significant, our model of isotopic evolution appears to be in broad agreement with radionuclide observations, and for the first time links atmospheric measurements of radioxenon isotopic ratios to estimates of seismic yield. Carrigan et al., Scientific Reports 6, Article number: 23032 (2016) doi:10.1038/srep23032

  10. Performance analysis of a complete adiabatic logic system driven by the proposed power clock generator

    International Nuclear Information System (INIS)

    Kanungo, Jitendra; Dasgupta, S.

    2014-01-01

    We analyze the energy performance of a complete adiabatic circuit/system including the Power Clock Generator (PCG) at the 90 nm CMOS technology node. The energy performance in terms of the conversion efficiency of the PCG is extensively carried out under the variations of supply voltage, process corner and the driver transistor's width. We propose an energy-efficient singe cycle control circuit based on the two-stage comparator for the synchronous charge recovery sinusoidal power clock generator (PCG). The proposed PCG is used to drive the 4-bit adiabatic Ripple Carry Adder (RCA) and their simulation results are compared with the adiabatic RCA driven by the reported PCG. We have also simulated the logically equivalent static CMOS RCA circuit to compare the energy saving of adiabatic and non-adiabatic logic circuits. In the clock frequency range from 25 MHz to 1GHz, the proposed PCG gives a maximum conversion efficiency of 56.48%. This research work shows how the design of an efficient PCG increases the energy saving of adiabatic logic. (semiconductor integrated circuits)

  11. Nucleation Characteristics in Physical Experiments/explosions

    International Nuclear Information System (INIS)

    Henry, R.E.; Fauske, Hans K.

    1976-01-01

    Large-scale vapor explosion experiments have shown that intimate contact between hot and cold liquids, and a temperature upon contact that is greater than the spontaneous nucleation temperature of the system, are two necessary conditions for the onset of large scale vapor explosions. A model, based on spontaneous nucleation of the homogeneous type, has been proposed to describe the relevant processes and the resulting energetics for explosive boiling systems. The model considers that spontaneous nucleation cannot occur either during the relief time for constant volume heating or until the thermal boundary layer is sufficiently thick to support a vapor cavity of the critical size. After nucleation, bubble growth does not occur until an acoustic wave establishes a pressure gradient in the cold liquid. These considerations lead to the prediction that, for a given temperature, drops greater than a critical size will remain in film boiling due to coalescence of vapor nuclei and drops smaller than this value will wet and be captured by the hot liquid surface. These results are compared to small drop data for well-wetted systems and excellent agreement is obtained between the observed behavior and the model predictions. In conclusion: A model, based on spontaneous nucleation, has been proposed to describe vaporization potential and behavior upon contact in a liquid/liquid system. This behavior is determined by the size of the liquid mass, single-phase pressurization and acoustic relief, nucleation frequency due to random density fluctuations, the initiation of unstable growth and acoustic relief, and the development of the thermal boundary layer in the cold liquid. The proposed model predicts that the stability of a given size drop upon intimate contact with another liquid is extremely dependent upon the interface temperature. For low interface temperatures, large masses will be captured by the hot liquid and the resulting vaporization rates will be extremely low because

  12. Thermal reservoir sizing for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)

    2012-07-01

    Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

  13. Bias-corrected estimation in potentially mildly explosive autoregressive models

    DEFF Research Database (Denmark)

    Haufmann, Hendrik; Kruse, Robinson

    This paper provides a comprehensive Monte Carlo comparison of different finite-sample bias-correction methods for autoregressive processes. We consider classic situations where the process is either stationary or exhibits a unit root. Importantly, the case of mildly explosive behaviour is studied...... that the indirect inference approach oers a valuable alternative to other existing techniques. Its performance (measured by its bias and root mean squared error) is balanced and highly competitive across many different settings. A clear advantage is its applicability for mildly explosive processes. In an empirical...

  14. Optimal control of the power adiabatic stroke of an optomechanical heat engine.

    Science.gov (United States)

    Bathaee, M; Bahrampour, A R

    2016-08-01

    We consider the power adiabatic stroke of the Otto optomechanical heat engine introduced in Phys. Rev. Lett. 112, 150602 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.150602. We derive the maximum extractable work of both optomechanical normal modes in the minimum time while the system experiences quantum friction effects. We show that the total work done by the system in the power adiabatic stroke is optimized by a bang-bang control. The time duration of the power adiabatic stroke is of the order of the inverse of the effective optomechanical-coupling coefficient. The optimal phase-space trajectory of the Otto cycle for both optomechanical normal modes is also obtained.

  15. K-FIX(GT): A computer program for modeling the expansion phase of steam explosions within complex three dimensional cavities

    International Nuclear Information System (INIS)

    Hyder, M.L.; Farawila, Y.M.; Abdel-Khalik, S.I.; Halvorson, P.J.

    1992-05-01

    In the development of the Severe Accident Analysis Program for the Savannah River production reactors, it was recognized that certain accidents have the potential for causing damaging steam explosions. The massive SRS reactor buildings are likely to withstand any imaginable steam explosion. However, reactor components and building structures including hatches, ventilation ducts, etc., could be at risk if such an explosion occurred. No tools were available to estimate the effects of such explosions on actual structures. To meet this need, the Savannah River Laboratory contracted with the Georgia Institute of Technology Research Institute for development of a computer-based calculational tool for estimating the effects of steam explosions. The goal for this study was to develop a computer code that could be used parametrically to predict the effects of various steam explosions on their surroundings. This would be able to predict whether a steam explosion of a given magnitude would be likely to fail a particular structure. This would require, of course, that the magnitude of the explosion be specified through some combination of judgment and calculation. The requested code, identified as the K-FIX(GT) code, was developed and delivered by the contractor, along with extensive documentation. The several individual reports that constitute the documentation are each being issued as a separate WSRC report. Documentation includes several model calculations, and representation of these in graphic form. This report gives detailed instructions for the use of the code, including identification of all input parameters required

  16. Quantum trajectories for time-dependent adiabatic master equations

    Science.gov (United States)

    Yip, Ka Wa; Albash, Tameem; Lidar, Daniel A.

    2018-02-01

    We describe a quantum trajectories technique for the unraveling of the quantum adiabatic master equation in Lindblad form. By evolving a complex state vector of dimension N instead of a complex density matrix of dimension N2, simulations of larger system sizes become feasible. The cost of running many trajectories, which is required to recover the master equation evolution, can be minimized by running the trajectories in parallel, making this method suitable for high performance computing clusters. In general, the trajectories method can provide up to a factor N advantage over directly solving the master equation. In special cases where only the expectation values of certain observables are desired, an advantage of up to a factor N2 is possible. We test the method by demonstrating agreement with direct solution of the quantum adiabatic master equation for 8-qubit quantum annealing examples. We also apply the quantum trajectories method to a 16-qubit example originally introduced to demonstrate the role of tunneling in quantum annealing, which is significantly more time consuming to solve directly using the master equation. The quantum trajectories method provides insight into individual quantum jump trajectories and their statistics, thus shedding light on open system quantum adiabatic evolution beyond the master equation.

  17. Smooth transition from sudden to adiabatic states in heavy-ion fusion reactions at deep-subbarrier incident energies

    International Nuclear Information System (INIS)

    Takatoshi, Ichikawa; Kouichi, Hagino; Akira, Iwamoto

    2011-01-01

    We propose a novel extension of the standard coupled-channel (CC) model in order to account for the steep falloff of fusion cross sections at deep-subbarrier incident energies. We introduce a damping factor in the coupling potential in the CC model, simulating smooth transitions from sudden to adiabatic states in deep- subbarrier fusion reactions. The CC model extended with the damping factor can reproduce well not only the steep falloff of the fusion cross section but also the saturation of the logarithmic derivatives for the fusion cross sections at deep-subbarrier energies for the 16 O+ 208 Pb, 64 Ni+ 64 Ni, and 58 Ni+ 58 Ni reactions at the deep-subbarrier energies. The important point in our model is that the transition takes place at different places for each Eigen channel. We conclude that the smooth transition from the two-body to the adiabatic one-body potential is responsible for the steep falloff of the fusion cross section

  18. A strategy for the application of steam explosion codes to reactor analysis

    International Nuclear Information System (INIS)

    Moriyama, Kiyofumi; Nakamura, Hideo

    2006-01-01

    A technical view on the strategy for the application of steam explosion codes for plant scale analysis is described. It includes assumption of triggering at the time of peak premixed melt mass, tuning of the explosion model on typical alumina steam explosion data, consideration of void and solidification effects as primary mechanism to limit the premixed mass and explosion energetics, choice of simple heat partition models affecting evaporation. The view was developed through experiences in development, verification and application of a steam explosion simulation code, JASMINE, at Japan Atomic Energy Agency (JAEA), as well as participation in OECD SERENA Phase-1 program. (author)

  19. Semiclassical Monte Carlo: A first principles approach to non-adiabatic molecular dynamics

    International Nuclear Information System (INIS)

    White, Alexander J.; Gorshkov, Vyacheslav N.; Wang, Ruixi; Tretiak, Sergei; Mozyrsky, Dmitry

    2014-01-01

    Modeling the dynamics of photophysical and (photo)chemical reactions in extended molecular systems is a new frontier for quantum chemistry. Many dynamical phenomena, such as intersystem crossing, non-radiative relaxation, and charge and energy transfer, require a non-adiabatic description which incorporate transitions between electronic states. Additionally, these dynamics are often highly sensitive to quantum coherences and interference effects. Several methods exist to simulate non-adiabatic dynamics; however, they are typically either too expensive to be applied to large molecular systems (10's-100's of atoms), or they are based on ad hoc schemes which may include severe approximations due to inconsistencies in classical and quantum mechanics. We present, in detail, an algorithm based on Monte Carlo sampling of the semiclassical time-dependent wavefunction that involves running simple surface hopping dynamics, followed by a post-processing step which adds little cost. The method requires only a few quantities from quantum chemistry calculations, can systematically be improved, and provides excellent agreement with exact quantum mechanical results. Here we show excellent agreement with exact solutions for scattering results of standard test problems. Additionally, we find that convergence of the wavefunction is controlled by complex valued phase factors, the size of the non-adiabatic coupling region, and the choice of sampling function. These results help in determining the range of applicability of the method, and provide a starting point for further improvement

  20. Explosive material treatment in particular the explosive compaction of powders

    International Nuclear Information System (INIS)

    Pruemmer, R.

    1985-01-01

    The constructive use of explosives in the last decades has led to new procedures in manufacturing techniques. The most important of these are explosive forming and cladding, the latter especially for the production of compound materials. The method of explosive compaction has the highest potential for further innovation. Almost theoretical densities are achievable in the green compacts as the pressure released by detonating explosives are very high. Also, the production of new conditions of materials (metastable high pressure phases) is possible. (orig.) [de

  1. Evaluation of blast wave damage from very large unconfined vapour cloud explosions

    International Nuclear Information System (INIS)

    Munday, G.

    1975-01-01

    A mathematical model is described for estimating the damage potential from unconfined vapour cloud explosions. An attempt has been made to cover the salient details of the explosive phenomenon including finite flame accelerations and finite vapour cloud sizes. The model has been evaluated against two industrial incidents and the results extrapolated to large-volume vapour clouds. The authors conclude, on the evidence of this model, that great care must be taken in the evaluation of the explosion hazard from the probable occurrence of very large unconfined explosions even at distances in excess of 1 km from the centre of initiation. (author)

  2. Analysis, comparison, and modeling of radar interferometry, date of surface deformation signals associated with underground explosions, mine collapses and earthquakes. Phase I: underground explosions, Nevada Test Site

    International Nuclear Information System (INIS)

    Foxall, W; Vincent, P; Walter, W

    1999-01-01

    We have previously presented simple elastic deformation modeling results for three classes of seismic events of concern in monitoring the CTBT-underground explosions, mine collapses and earthquakes. Those results explored the theoretical detectability of each event type using synthetic aperture radar interferometry (InSAR) based on commercially available satellite data. In those studies we identified and compared the characteristics of synthetic interferograms that distinguish each event type, as well the ability of the interferograms to constrain source parameters. These idealized modeling results, together with preliminary analysis of InSAR data for the 1995 mb 5.2 Solvay mine collapse in southwestern Wyoming, suggested that InSAR data used in conjunction with regional seismic monitoring holds great potential for CTBT discrimination and seismic source analysis, as well as providing accurate ground truth parameters for regional calibration events. In this paper we further examine the detectability and ''discriminating'' power of InSAR by presenting results from InSAR data processing, analysis and modeling of the surface deformation signals associated with underground explosions. Specifically, we present results of a detailed study of coseismic and postseismic surface deformation signals associated with underground nuclear and chemical explosion tests at the Nevada Test Site (NTS). Several interferograms were formed from raw ERS-1/2 radar data covering different time spans and epochs beginning just prior to the last U.S. nuclear tests in 1992 and ending in 1996. These interferograms have yielded information about the nature and duration of the source processes that produced the surface deformations associated with these events. A critical result of this study is that significant post-event surface deformation associated with underground nuclear explosions detonated at depths in excess of 600 meters can be detected using differential radar interferometry. An

  3. One-Dimensional Time to Explosion (Thermal Sensitivity) of ANPZ

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hust, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McClelland, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gresshoff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-11-12

    Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 C) and the violence from thermal explosion may cause a significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. This report summarizes the recent ODTX experimental data and modeling results for 2,6-diamino-3,5-dintropyrazine (ANPZ).

  4. Supernova neutrinos and explosive nucleosynthesis

    Science.gov (United States)

    Kajino, T.; Aoki, W.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Mathews, G. J.; Nakamura, K.; Shibagaki, S.; Suzuki, T.

    2014-05-01

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes 7Li, 11B, 92Nb, 138La and 180Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ13, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements 11B and 7Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ13, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  5. Supernova neutrinos and explosive nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Aoki, W. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Cheoun, M.-K. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Hayakawa, T. [Japan Atomic Energy Agency, Shirakara-Shirane 2-4, Tokai-mura, Ibaraki 319-1195 (Japan); Hidaka, J.; Hirai, Y.; Shibagaki, S. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Nakamura, K. [Faculty of Science and Engineering, Waseda University, Ohkubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Suzuki, T. [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-05-09

    Core-collapse supernovae eject huge amount of flux of energetic neutrinos. We studied the explosive nucleosyn-thesis in supernovae and found that several isotopes {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta as well as r-process nuclei are affected by the neutrino interactions. The abundance of these isotopes therefore depends strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. We discuss first how to determine the neutrino temperatures in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. We then study the effects of neutrino oscillation on their abundances, and propose a novel method to determine the still unknown neutrino oscillation parameters, mass hierarchy and θ{sub 13}, simultaneously. There is recent evidence that SiC X grains from the Murchison meteorite may contain supernova-produced light elements {sup 11}B and {sup 7}Li encapsulated in the presolar grains. Combining the recent experimental constraints on θ{sub 13}, we show that our method sug-gests at a marginal preference for an inverted neutrino mass hierarchy. Finally, we discuss supernova relic neutrinos that may indicate the softness of the equation of state (EoS) of nuclear matter as well as adiabatic conditions of the neutrino oscillation.

  6. Mid-range adiabatic wireless energy transfer via a mediator coil

    International Nuclear Information System (INIS)

    Rangelov, A.A.; Vitanov, N.V.

    2012-01-01

    A technique for efficient mid-range wireless energy transfer between two coils via a mediator coil is proposed. By varying the coil frequencies, three resonances are created: emitter–mediator (EM), mediator–receiver (MR) and emitter–receiver (ER). If the frequency sweeps are adiabatic and such that the EM resonance precedes the MR resonance, the energy flows sequentially along the chain emitter–mediator–receiver. If the MR resonance precedes the EM resonance, then the energy flows directly from the emitter to the receiver via the ER resonance; then the losses from the mediator are suppressed. This technique is robust against noise, resonant constraints and external interferences. - Highlights: ► Efficient and robust mid-range wireless energy transfer via a mediator coil. ► The adiabatic energy transfer is analogous to adiabatic passage in quantum optics. ► Wireless energy transfer is insensitive to any resonant constraints. ► Wireless energy transfer is insensitive to noise in the neighborhood of the coils.

  7. Waking the undead: Implications of a soft explosive model for the timing of placental mammal diversification.

    Science.gov (United States)

    Springer, Mark S; Emerling, Christopher A; Meredith, Robert W; Janečka, Jan E; Eizirik, Eduardo; Murphy, William J

    2017-01-01

    The explosive, long fuse, and short fuse models represent competing hypotheses for the timing of placental mammal diversification. Support for the explosive model, which posits both interordinal and intraordinal diversification after the KPg mass extinction, derives from morphological cladistic studies that place Cretaceous eutherians outside of crown Placentalia. By contrast, most molecular studies favor the long fuse model wherein interordinal cladogenesis occurred in the Cretaceous followed by intraordinal cladogenesis after the KPg boundary. Phillips (2016) proposed a soft explosive model that allows for the emergence of a few lineages (Xenarthra, Afrotheria, Euarchontoglires, Laurasiatheria) in the Cretaceous, but otherwise agrees with the explosive model in positing the majority of interordinal diversification after the KPg mass extinction. Phillips (2016) argues that rate transference errors associated with large body size and long lifespan have inflated previous estimates of interordinal divergence times, and further suggests that most interordinal divergences are positioned after the KPg boundary when rate transference errors are avoided through the elimination of calibrations in large-bodied and/or long lifespan clades. Here, we show that rate transference errors can also occur in the opposite direction and drag forward estimated divergence dates when calibrations in large-bodied/long lifespan clades are omitted. This dragging forward effect results in the occurrence of more than half a billion years of 'zombie lineages' on Phillips' preferred timetree. By contrast with ghost lineages, which are a logical byproduct of an incomplete fossil record, zombie lineages occur when estimated divergence dates are younger than the minimum age of the oldest crown fossils. We also present the results of new timetree analyses that address the rate transference problem highlighted by Phillips (2016) by deleting taxa that exceed thresholds for body size and lifespan

  8. η Condensate of Fermionic Atom Pairs via Adiabatic State Preparation

    International Nuclear Information System (INIS)

    Kantian, A.; Daley, A. J.; Zoller, P.

    2010-01-01

    We discuss how an η condensate, corresponding to an exact excited eigenstate of the Fermi-Hubbard model, can be produced with cold atoms in an optical lattice. Using time-dependent density matrix renormalization group methods, we analyze a state preparation scheme beginning from a band insulator state in an optical superlattice. This state can act as an important test case, both for adiabatic preparation methods and the implementation of the many-body Hamiltonian, and measurements on the final state can be used to help detect associated errors.

  9. Source characterization of underground explosions from hydrodynamic-to-elastic coupling simulations

    Science.gov (United States)

    Chiang, A.; Pitarka, A.; Ford, S. R.; Ezzedine, S. M.; Vorobiev, O.

    2017-12-01

    A major improvement in ground motion simulation capabilities for underground explosion monitoring during the first phase of the Source Physics Experiment (SPE) is the development of a wave propagation solver that can propagate explosion generated non-linear near field ground motions to the far-field. The calculation is done using a hybrid modeling approach with a one-way hydrodynamic-to-elastic coupling in three dimensions where near-field motions are computed using GEODYN-L, a Lagrangian hydrodynamics code, and then passed to WPP, an elastic finite-difference code for seismic waveform modeling. The advancement in ground motion simulation capabilities gives us the opportunity to assess moment tensor inversion of a realistic volumetric source with near-field effects in a controlled setting, where we can evaluate the recovered source properties as a function of modeling parameters (i.e. velocity model) and can provide insights into previous source studies on SPE Phase I chemical shots and other historical nuclear explosions. For example the moment tensor inversion of far-field SPE seismic data demonstrated while vertical motions are well-modeled using existing velocity models large misfits still persist in predicting tangential shear wave motions from explosions. One possible explanation we can explore is errors and uncertainties from the underlying Earth model. Here we investigate the recovered moment tensor solution, particularly on the non-volumetric component, by inverting far-field ground motions simulated from physics-based explosion source models in fractured material, where the physics-based source models are based on the modeling of SPE-4P, SPE-5 and SPE-6 near-field data. The hybrid modeling approach provides new prospects in modeling explosion source and understanding the uncertainties associated with it.

  10. Correlated mixture between adiabatic and isocurvature fluctuations and recent CMB observations

    International Nuclear Information System (INIS)

    Andrade, Ana Paula A.; Wuensche, Carlos Alexandre; Ribeiro, Andre Luis Batista

    2005-01-01

    This work presents a reduced χ ν 2 test to search for non-Gaussian signals in the cosmic microwave background radiation (CMBR) TT power spectrum of recent CMBR data, Wilkinson Anisotropy Microwave Probe, Arcminute Cosmology Bolometer Array Receiver, and Cosmic Background Imager data sets, assuming a mixed density field including adiabatic and isocurvature fluctuations. We assume a skew positive mixed model with adiabatic inflation perturbations plus additional isocurvature perturbations possibly produced by topological defects. The joint probability distribution used in this context is a weighted combination of Gaussian and non-Gaussian random fields. Results from simulations of CMBR temperature for the mixed field show a distinct signature in CMB power spectrum for very small deviations (∼0.1%) from a pure Gaussian field, and can be used as a direct test for the nature of primordial fluctuations. A reduced χ ν 2 test applied on the most recent CMBR observations reveals that an isocurvature fluctuations field is not ruled out and indeed permits a very good description for a flat geometry Λ-CDM Universe, χ 930 2 ∼1.5, rather than the simple inflationary standard model with χ 930 2 ∼2.3. This result may looks is particular discrepant with the reduced χ 2 of 1.07 obtained with the same model in Spergel et al. [Astrophys. J. 148, 175 (2003)] for temperature only, however, our work is restricted to a region of the parameter space that does not include the best fit model for TT only of Spergel et al.

  11. Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells

    NARCIS (Netherlands)

    Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla Varas, J.

    2012-01-01

    The Klotz Group (KG), an international group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced

  12. Modelling loading and break-up of RC structure due to internal explosion of fragmenting shells

    NARCIS (Netherlands)

    Weerheijm, J.; Stolz, A.; Riedel, W.; Mediavilla, J.

    2012-01-01

    The Klotz Group (KG), an mtemational group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced

  13. Distributed capillary adiabatic tissue homogeneity model in parametric multi-channel blind AIF estimation using DCE-MRI.

    Science.gov (United States)

    Kratochvíla, Jiří; Jiřík, Radovan; Bartoš, Michal; Standara, Michal; Starčuk, Zenon; Taxt, Torfinn

    2016-03-01

    One of the main challenges in quantitative dynamic contrast-enhanced (DCE) MRI is estimation of the arterial input function (AIF). Usually, the signal from a single artery (ignoring contrast dispersion, partial volume effects and flow artifacts) or a population average of such signals (also ignoring variability between patients) is used. Multi-channel blind deconvolution is an alternative approach avoiding most of these problems. The AIF is estimated directly from the measured tracer concentration curves in several tissues. This contribution extends the published methods of multi-channel blind deconvolution by applying a more realistic model of the impulse residue function, the distributed capillary adiabatic tissue homogeneity model (DCATH). In addition, an alternative AIF model is used and several AIF-scaling methods are tested. The proposed method is evaluated on synthetic data with respect to the number of tissue regions and to the signal-to-noise ratio. Evaluation on clinical data (renal cell carcinoma patients before and after the beginning of the treatment) gave consistent results. An initial evaluation on clinical data indicates more reliable and less noise sensitive perfusion parameter estimates. Blind multi-channel deconvolution using the DCATH model might be a method of choice for AIF estimation in a clinical setup. © 2015 Wiley Periodicals, Inc.

  14. Off-center point explosion in a spheroid

    International Nuclear Information System (INIS)

    Morita, Kazuhiko; Sakashita, Shiro

    1978-01-01

    An off-center point explosion in a spheroid with exponential or Gaussian density distribution is investigated by applying the generalized Laumbach and Probstein method. For a typical example, we calculate the explosion in a spheroid with the eccentricity e = 0.7. If the separation distance between the center of the spheroid and the explosion point is larger than three times of the density scale height, the shock wave may almost propagate toward the direction of the minor axis of symmetry, within the polar angle of 30 0 . The shock envelope elongates toward the same direction and may form a polar jet and/or a tilted jet. But, in the case of an explosion in the equatorial plane (perpendicular to the minor axis of symmetry), two plasmas with the same form may be ejected into two different directions with the angle smaller than 180 0 . Explosion models of double radio sources and related objects are suggested. (author)

  15. Accuracy of the adiabatic-impulse approximation for closed and open quantum systems

    Science.gov (United States)

    Tomka, Michael; Campos Venuti, Lorenzo; Zanardi, Paolo

    2018-03-01

    We study the adiabatic-impulse approximation (AIA) as a tool to approximate the time evolution of quantum states when driven through a region of small gap. Such small-gap regions are a common situation in adiabatic quantum computing and having reliable approximations is important in this context. The AIA originates from the Kibble-Zurek theory applied to continuous quantum phase transitions. The Kibble-Zurek mechanism was developed to predict the power-law scaling of the defect density across a continuous quantum phase transition. Instead, here we quantify the accuracy of the AIA via the trace norm distance with respect to the exact evolved state. As expected, we find that for short times or fast protocols, the AIA outperforms the simple adiabatic approximation. However, for large times or slow protocols, the situation is actually reversed and the AIA provides a worse approximation. Nevertheless, we found a variation of the AIA that can perform better than the adiabatic one. This counterintuitive modification consists in crossing the region of small gap twice. Our findings are illustrated by several examples of driven closed and open quantum systems.

  16. Simulation of explosive welding with ANFO mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, A.A. Akbari; Burley, Stephen J.; Al-Hassani, S.T.S. [Department of Mechanical, Aerospace and Manufacturing Engineering, UMIST, PO Box 88, Manchester M60 1QD (United Kingdom); Byers Brown, W. [Mass Action Research Consultancy, Devonshire House, 14 Corbar Road, Buxton, SK17 6RQ (United Kingdom)

    2004-06-01

    The work described here arose from a study into explosive welding. As part of that study, the impact velocity of stainless steel and titanium plates to grazing detonation of ANFO/perlite, the velocity of detonation were measured. Computer simulation required a new model which copes with an equation of state of low explosives. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  17. Adiabatic resonant oscillations of solar neutrinos in three generations

    International Nuclear Information System (INIS)

    Kim, C.W.; Sze, W.K.

    1987-01-01

    The Mikheyev-Smirnov-Wolfenstein model of resonant solar-neutrino oscillations is discussed for three generations of leptons. Assuming adiabatic transitions, bounds for the μ- and e-neutrinos mass-squared difference Δ/sub 21,0/ are obtained as a function of the e-μ mixing angle theta 1 . The allowed region in the Δ/sub 21,0/-theta 1 plot that would solve the solar-neutrino problem is shown to be substantially larger than that of the two-generation case. In particular, the difference between the two- and three-generation cases becomes significant for theta 1 larger than --20 0

  18. Electronic energy transfer through non-adiabatic vibrational-electronic resonance. I. Theory for a dimer

    Science.gov (United States)

    Tiwari, Vivek; Peters, William K.; Jonas, David M.

    2017-10-01

    Non-adiabatic vibrational-electronic resonance in the excited electronic states of natural photosynthetic antennas drastically alters the adiabatic framework, in which electronic energy transfer has been conventionally studied, and suggests the possibility of exploiting non-adiabatic dynamics for directed energy transfer. Here, a generalized dimer model incorporates asymmetries between pigments, coupling to the environment, and the doubly excited state relevant for nonlinear spectroscopy. For this generalized dimer model, the vibrational tuning vector that drives energy transfer is derived and connected to decoherence between singly excited states. A correlation vector is connected to decoherence between the ground state and the doubly excited state. Optical decoherence between the ground and singly excited states involves linear combinations of the correlation and tuning vectors. Excitonic coupling modifies the tuning vector. The correlation and tuning vectors are not always orthogonal, and both can be asymmetric under pigment exchange, which affects energy transfer. For equal pigment vibrational frequencies, the nonadiabatic tuning vector becomes an anti-correlated delocalized linear combination of intramolecular vibrations of the two pigments, and the nonadiabatic energy transfer dynamics become separable. With exchange symmetry, the correlation and tuning vectors become delocalized intramolecular vibrations that are symmetric and antisymmetric under pigment exchange. Diabatic criteria for vibrational-excitonic resonance demonstrate that anti-correlated vibrations increase the range and speed of vibronically resonant energy transfer (the Golden Rule rate is a factor of 2 faster). A partial trace analysis shows that vibronic decoherence for a vibrational-excitonic resonance between two excitons is slower than their purely excitonic decoherence.

  19. Adiabatic theory of nonlinear electron cyclotron resonance heating

    International Nuclear Information System (INIS)

    Kotel'nikov, I.A.; Stupakov, G.V.

    1989-01-01

    Plasma heating at electron frequency by an ordinary wave propagating at right angle to unidirectional magnetic field is treated. Injected microwave power is assumed to be so large that relativistic change of electron gyrofrequency during one flight thorugh the wave beam is much greater than inverse time of flight. The electron motion in the wave field is described using Hamiltonian formalism in adiabatic approximation. It is shown that energy coupling from the wave to electrons is due to a bifurcation of electron trajectory which results in a jumpm of the adiabatic invariant. The probability of bifurcational transition from one trajectory to another is calculated analytically and is used for the estimation of the beam power absorbed in plasma. 6 refs.; 2 figs

  20. Diagnosis and Modeling of the Explosive Development of Winter Storms: Sensitivity to PBL Schemes

    Science.gov (United States)

    Liberato, Margarida L. R.; Pradhan, Prabodha K.

    2014-05-01

    The correct representation of extreme windstorms in regional models is of great importance for impact studies of climate change. The Iberian Peninsula has recently witnessed major damage from winter extratropical intense cyclones like Klaus (January 2009), Xynthia (February 2010) and Gong (January 2013) which formed over the mid-Atlantic, experienced explosive intensification while travelling eastwards at lower latitudes than usual [Liberato et al. 2011; 2013]. In this paper the explosive development of these storms is simulated by the advanced mesoscale Weather Research and Forecasting Model (WRF v 3.4.1), initialized with NCEP Final Analysis (FNL) data as initial and lateral boundary conditions (boundary conditions updated in every 3 hours intervals). The simulation experiments are conducted with two domains, a coarser (25km) and nested (8.333km), covering the entire North Atlantic and Iberian Peninsula region. The characteristics of these storms (e.g. wind speed, precipitation) are studied from WRF model and compared with multiple observations. In this context simulations with different Planetary Boundary Layer (PBL) schemes are performed. This approach aims at understanding which mechanisms favor the explosive intensification of these storms at a lower than usual latitudes, thus improving the knowledge of atmospheric dynamics (including small-scale processes) on controlling the life cycle of midlatitude extreme storms and contributing to the improvement in predictability and in our ability to forecast storms' impacts over Iberian Peninsula. Acknowledgments: This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project STORMEx FCOMP-01-0124-FEDER- 019524 (PTDC/AAC-CLI/121339/2010). References: Liberato M.L.R., J.G. Pinto, I.F. Trigo, R.M. Trigo (2011) Klaus - an

  1. On the adiabatic theorem in quantum statistical mechanics

    International Nuclear Information System (INIS)

    Narnhofer, H.; Thirring, W.

    1982-01-01

    We show that with suitable assumptions the equilibrium states are exactly the states invariant under adiabatic local perturbations. The relevance of this fact to the problem of ergodicity is discussed. (Author)

  2. Adiabatic photo-steering theory in topological insulators

    Science.gov (United States)

    Inoue, Jun-ichi

    2014-12-01

    Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane-Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed.

  3. Adiabatic photo-steering theory in topological insulators

    International Nuclear Information System (INIS)

    Inoue, Jun-ichi

    2014-01-01

    Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane–Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed. (focus issue review)

  4. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)

    Science.gov (United States)

    2010-01-08

    ... sensitive slurry and water gel explosives. Blasting caps. Blasting gelatin. Blasting powder. BTNEC [bis.... Explosive conitrates. Explosive gelatins. Explosive liquids. Explosive mixtures containing oxygen-releasing... powder. Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating...

  5. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Science.gov (United States)

    2010-11-17

    ..., including non-cap sensitive slurry and water gel explosives. Blasting caps. Blasting gelatin. Blasting.... Explosive conitrates. Explosive gelatins. Explosive liquids. Explosive mixtures containing oxygen-releasing... powder. Fulminate of mercury. Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating...

  6. Modeling of thermal explosion under pressure in metal ceramic systems

    International Nuclear Information System (INIS)

    Shapiro, M.; Dudko, V.; Skachek, B.; Matvienko, A.; Gotman, I.; Gutmanas, E.Y.

    1998-01-01

    The process of reactive in situ synthesis of dense ceramic matrix composites in Ti-B-C, Ti-B-N, Ti-Si-N systems is modeled. These ceramics are fabricated on the basis of compacted blends of ceramic powders, namely Ti-B 4 C and/or Ti-BN. The objectives of the project are to identify and investigate the optimal thermal conditions preferable for production of fully dense ceramic matrix composites. Towards this goal heat transfer and combustion in dense and porous ceramic blends are investigated during monotonous heating at a constant rate. This process is modeled using a heat transfer-combustion model with kinetic parameters determined from the differential thermal analysis of the experimental data. The kinetic burning parameters and the model developed are further used to describe the thermal explosion synthesis in a restrained die under pressure. It is shown that heat removal from the reaction zone affects the combustion process and the final phase composition

  7. What factors control superficial lava dome explosivity?

    Science.gov (United States)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J

    2015-09-30

    Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management.

  8. Aspects of hyperspherical adiabaticity in an atomic-gas Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Kushibe, Daisuke; Mutou, Masaki; Morishita, Toru; Watanabe, Shinichi; Matsuzawa, Michio

    2004-01-01

    Excitation of an atomic-gas Bose-Einstein condensate (BEC) in the zeroth-order ground-state channel is studied with the hyperspherical adiabatic method of Bohn et al. [Bohn et al., Phys. Rev. A 58, 584 (1998)] suitably generalized to accommodate the anisotropic trapping potential. The method exploits the system's size as an adiabatic parameter so that the explicit size dependence is immediately conducive to the virial theorem. The oscillation frequencies associated with the monopole (breathing) and quadrupole modes thus emerge naturally and converge to the well-known Thomas-Fermi limits. Analysis of the single-particle density and the projected excitation wave function shows that the excitation in the single hyperspherical ground-state channel merely represents a progressive increase in occupancy of the first excited single-particle state. The work paves the way for applying the adiabatic picture to other BEC phenomena

  9. Bond selective chemistry beyond the adiabatic approximation

    Energy Technology Data Exchange (ETDEWEB)

    Butler, L.J. [Univ. of Chicago, IL (United States)

    1993-12-01

    One of the most important challenges in chemistry is to develop predictive ability for the branching between energetically allowed chemical reaction pathways. Such predictive capability, coupled with a fundamental understanding of the important molecular interactions, is essential to the development and utilization of new fuels and the design of efficient combustion processes. Existing transition state and exact quantum theories successfully predict the branching between available product channels for systems in which each reaction coordinate can be adequately described by different paths along a single adiabatic potential energy surface. In particular, unimolecular dissociation following thermal, infrared multiphoton, or overtone excitation in the ground state yields a branching between energetically allowed product channels which can be successfully predicted by the application of statistical theories, i.e. the weakest bond breaks. (The predictions are particularly good for competing reactions in which when there is no saddle point along the reaction coordinates, as in simple bond fission reactions.) The predicted lack of bond selectivity results from the assumption of rapid internal vibrational energy redistribution and the implicit use of a single adiabatic Born-Oppenheimer potential energy surface for the reaction. However, the adiabatic approximation is not valid for the reaction of a wide variety of energetic materials and organic fuels; coupling between the electronic states of the reacting species play a a key role in determining the selectivity of the chemical reactions induced. The work described below investigated the central role played by coupling between electronic states in polyatomic molecules in determining the selective branching between energetically allowed fragmentation pathways in two key systems.

  10. Adiabatic theorem and spectral concentration

    International Nuclear Information System (INIS)

    Nenciu, G.

    1981-01-01

    The spectral concentration of arbitrary order, for the Stark effect is proved to exist for a large class of Hamiltonians appearing in nonrelativistic and relativistic quantum mechanics. The results are consequences of an abstract theorem about the spectral concentration for self-ad oint operators. A general form of the adiabatic theorem of quantum mechanics, generalizing an earlier result of the author as well as some results of Lenard, is also proved [ru

  11. Evolution of fNL to the adiabatic limit

    Science.gov (United States)

    Elliston, Joseph; Mulryne, David J.; Seery, David; Tavakol, Reza

    2011-11-01

    We study inflationary perturbations in multiple-field models, for which ζ typically evolves until all isocurvature modes decay — the "adiabatic limit". We use numerical methods to explore the sensitivity of the local-shape bispectrum to the process by which this limit is achieved, finding an appreciable dependence on model-specific data such as the time at which slow-roll breaks down or the timescale of reheating. In models with a sum-separable potential where the isocurvature modes decay before the end of the slow-roll phase we give an analytic criterion for the asymptotic value of fNL to be large. Other examples can be constructed using a waterfall field to terminate inflation while fNL is transiently large, caused by descent from a ridge or convergence into a valley. We show that these two types of evolution are distinguished by the sign of the bispectrum, and give approximate expressions for the peak fNL.

  12. Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy

    Science.gov (United States)

    Kittell, Aaron W.; Hyde, James S.

    2015-01-01

    Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has been used to improve sensitivity relative to sinusoidal magnetic field modulation, increase the range of inter-spin distances that can be measured under near physiological conditions, and enhance spectral resolution in copper (II) spectra. In the present work, the method is extended to CW microwave power saturation of spin-labeled T4 Lysozyme (T4L). As in the cited papers, rapid triangular sweep of the polarizing magnetic field was superimposed on slow sweep across the spectrum. Adiabatic rapid passage (ARP) effects were encountered in samples undergoing very slow rotational diffusion as the triangular magnetic field sweep rate was increased. The paper reports results of variation of experimental parameters at the interface of adiabatic and non-adiabatic rapid sweep conditions. Comparison of the forward (up) and reverse (down) triangular sweeps is shown to be a good indicator of the presence of rapid passage effects. Spectral turning points can be distinguished from spectral regions between turning points in two ways: differential microwave power saturation and differential passage effects. Oxygen accessibility data are shown under NARS conditions that appear similar to conventional field modulation data. However, the sensitivity is much higher, permitting, in principle, experiments at substantially lower protein concentrations. Spectral displays were obtained that appear sensitive to rotational diffusion in the range of rotational correlation times of 10−3 to 10−7 s in a manner that is analogous to saturation transfer spectroscopy. PMID:25917132

  13. A Second-Order Turbulence Model Based on a Reynolds Stress Approach for Two-Phase Flow—Part I: Adiabatic Cases

    Directory of Open Access Journals (Sweden)

    S. Mimouni

    2009-01-01

    Full Text Available In our work in 2008, we evaluated the aptitude of the code Neptune_CFD to reproduce the incidence of a structure topped by vanes on a boiling layer, within the framework of the Neptune project. The objective was to reproduce the main effects of the spacer grids. The turbulence of the liquid phase was modeled by a first-order K-ε model. We show in this paper that this model is unable to describe the turbulence of rotating flows, in accordance with the theory. The objective of this paper is to improve the turbulence modeling of the liquid phase by a second turbulence model based on a Rij-ε approach. Results obtained on typical single-phase cases highlight the improvement of the prediction for all computed values. We tested the turbulence model Rij-ε implemented in the code versus typical adiabatic two-phase flow experiments. We check that the simulations with the Reynolds stress transport model (RSTM give satisfactory results in a simple geometry as compared to a K-ε model: this point is crucial before calculating rod bundle geometries where the K-ε model may fail.

  14. Comment on ''Semiclassical treatment of vibrational--translational energy transfer in the near-adiabatic approximation''

    International Nuclear Information System (INIS)

    Cady, W.A.; Clark, A.P.; Dickinson, A.S.

    1975-01-01

    Recently a near-adiabatic (perturbed stationary states) approximation was used in an investigation the collinear vibrational excitation of a harmonic oscillator. This approximation reduced the problem to that of obtaining transition probabilities for a harmonic oscillator with time-dependent forcing function. Cady derived an apparently exact solution for this problem. It is shown that this solution is not exact but that the solution results from making a further adiabatic approximation and a derivation is given that clearly shows the adiabatic character of this further approximation

  15. Adiabatic energization in the ring current and its relation to other source and loss terms

    Science.gov (United States)

    Liemohn, M. W.; Kozyra, J. U.; Clauer, C. R.; Khazanov, G. V.; Thomsen, M. F.

    2002-04-01

    The influence of adiabatic energization and deenergization effects, caused by particle drift in radial distance, on ring current growth rates and loss lifetimes is investigated. Growth and loss rates from simulation results of four storms (5 June 1991, 15 May 1997, 19 October 1998, and 25 September 1998) are examined and compared against the y component of the solar wind electric field (Ey,sw). Energy change rates with and without the inclusion of adiabatic energy changes are considered to isolate the influence of this mechanism in governing changes of ring current strength. It is found that the influence of adiabatic drift effects on the energy change rates is very large when energization and deenergization are considered separately as gain and loss mechanisms, often about an order of magnitude larger than all other source or loss terms combined. This is true not only during storm times, when the open drift path configuration of the hot ions dominates the physics of the ring current, but also during quiet times, when the small oscillation in L of the closed trajectories creates a large source and loss of energy each drift orbit. However, the net energy change from adiabatic drift is often smaller than other source and loss processes, especially during quiet times. Energization from adiabatic drift dominates ring current growth only during portions of the main phase of storms. Furthermore, the net-adiabatic energization is often positive, because some particles are lost in the inner magnetosphere before they can adiabatically deenergize. It is shown that the inclusion of only this net-adiabatic drift effect in the total source rate or loss lifetime (depending on the sign of the net-adiabatic energization) best matches the observed source and loss values from empirical Dst predictor methods (that is, for consistency, these values should be compared between the calculation methods). While adiabatic deenergization dominates the loss timescales for all Ey,sw values

  16. EVENT, Explosive Transients in Flow Networks

    International Nuclear Information System (INIS)

    Andrae, R.W.; Tang, P.K.; Bolstad, J.W.; Gregory, W.S.

    1985-01-01

    1 - Description of problem or function: A major concern of the chemical, nuclear, and mining industries is the occurrence of an explosion in one part of a facility and subsequent transmission of explosive effects through the ventilation system. An explosive event can cause performance degradation of the ventilation system or even structural failures. A more serious consequence is the release of hazardous materials to the environment if vital protective devices such as air filters, are damaged. EVENT was developed to investigate the effects of explosive transients through fluid-flow networks. Using the principles of fluid mechanics and thermodynamics, governing equations for the conservation of mass, energy, and momentum are formulated. These equations are applied to the complete network subdivided into two general components: nodes and branches. The nodes represent boundaries and internal junctions where the conservation of mass and energy applies. The branches can be ducts, valves, blowers, or filters. Since in EVENT the effect of the explosion, not the characteristics of the explosion itself, is of interest, the transient is simulated in the simplest possible way. A rapid addition of mass and energy to the system at certain locations is used. This representation is adequate for all of the network except the region where the explosion actually occurs. EVENT84 is a modification of EVENT which includes a new explosion chamber model subroutine based on the NOL BLAST program developed at the Naval Ordnance Laboratory, Silver Spring, Maryland. This subroutine calculates the confined explosion near-field parameters and supplies the time functions of energy and mass injection. Solid-phase or TNT-equivalent explosions (which simulate 'point source' explosions in nuclear facilities) as well as explosions in gas-air mixtures can be simulated. The four types of explosions EVENT84 simulates are TNT, hydrogen in air, acetylene in air, and tributyl phosphate (TBP or 'red oil

  17. Pyroshock Prediction of Ridge-Cut Explosive Bolts Using Hydrocodes

    Directory of Open Access Journals (Sweden)

    Juho Lee

    2016-01-01

    Full Text Available Pyrotechnic release devices such as explosive bolts are prevalent for many applications due to their merits: high reliability, high power-to-weight ratio, reasonable cost, and more. However, pyroshock generated by an explosive event can cause failures in electric components. Although pyroshock propagations are relatively well understood through many numerical and experimental studies, the prediction of pyroshock generation is still a very difficult problem. This study proposes a numerical method for predicting the pyroshock of a ridge-cut explosive bolt using a commercial hydrocode (ANSYS AUTODYN. A numerical model is established by integrating fluid-structure interaction and complex material models for high explosives and metals, including high explosive detonation, shock wave transmission and propagation, and stress wave propagation. To verify the proposed numerical scheme, pyroshock measurement experiments of the ridge-cut explosive bolts with two types of surrounding structures are performed using laser Doppler vibrometers (LDVs. The numerical analysis results provide accurate prediction in both the time (acceleration and frequency domains (maximax shock response spectra. In maximax shock response spectra, the peaks due to vibration modes of the structures are observed in both the experimental and numerical results. The numerical analysis also helps to identify the pyroshock generation source and the propagation routes.

  18. Liquid explosives

    CERN Document Server

    Liu, Jiping

    2015-01-01

    The book drawing on the author's nearly half a century of energetic materials research experience intends to systematically review the global researches on liquid explosives. The book focuses on the study of the conception, explosion mechanism, properties and preparation of liquid explosives. It provides a combination of theoretical knowledge and practical examples in a reader-friendly style. The book is likely to be interest of university researchers and graduate students in the fields of energetic materials, blasting engineering and mining.

  19. Path-integral isomorphic Hamiltonian for including nuclear quantum effects in non-adiabatic dynamics

    Science.gov (United States)

    Tao, Xuecheng; Shushkov, Philip; Miller, Thomas F.

    2018-03-01

    We describe a path-integral approach for including nuclear quantum effects in non-adiabatic chemical dynamics simulations. For a general physical system with multiple electronic energy levels, a corresponding isomorphic Hamiltonian is introduced such that Boltzmann sampling of the isomorphic Hamiltonian with classical nuclear degrees of freedom yields the exact quantum Boltzmann distribution for the original physical system. In the limit of a single electronic energy level, the isomorphic Hamiltonian reduces to the familiar cases of either ring polymer molecular dynamics (RPMD) or centroid molecular dynamics Hamiltonians, depending on the implementation. An advantage of the isomorphic Hamiltonian is that it can easily be combined with existing mixed quantum-classical dynamics methods, such as surface hopping or Ehrenfest dynamics, to enable the simulation of electronically non-adiabatic processes with nuclear quantum effects. We present numerical applications of the isomorphic Hamiltonian to model two- and three-level systems, with encouraging results that include improvement upon a previously reported combination of RPMD with surface hopping in the deep-tunneling regime.

  20. Steam explosion pretreatment of softwood: the effect of the explosive decompression on enzymatic digestibility.

    Science.gov (United States)

    Pielhop, Thomas; Amgarten, Janick; von Rohr, Philipp Rudolf; Studer, Michael H

    2016-01-01

    Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. The information available about the effect of the explosive decompression on the biochemical conversion is, however, very limited, and no studies prove that the latter is actually enhanced by the explosion. Hence, it is of great value to discern between the effect of the explosion on the one hand and the steaming on the other hand, to identify their particular influences on enzymatic digestibility. The effect of the explosive decompression in the steam explosion pretreatment of spruce wood chips on their enzymatic cellulose digestibility was studied systematically. The explosion had a high influence on digestibility, improving it by up to 90 % compared to a steam pretreatment without explosion. Two factors were identified to be essentially responsible for the effect of the explosion on enzymatic digestibility: pretreatment severity and pressure difference of the explosion. A higher pretreatment severity can soften up and weaken the lignocellulose structure more, so that the explosion can better break up the biomass and decrease its particle size, which enhances its digestibility. In particular, increasing the pressure difference of the explosion leads to more defibration, a smaller particle size and a better digestibility. Though differences were found in the micro- and nanostructure of exploded and non-exploded biomass, the only influence of the explosion on digestibility was found to be the macroscopic particle size reduction. Steam explosion treatments with a high severity and a high pressure difference of the explosion lead to a comparatively high cellulose digestibility of the-typically very recalcitrant-softwood biomass. This is the first study to show that explosion can enhance the enzymatic digestibility of lignocellulosic biomass. If the

  1. Adiabatic theory of Wannier threshold laws and ionization cross sections

    International Nuclear Information System (INIS)

    Macek, J.H.; Ovchinnikov, S.Y.

    1994-01-01

    Adiabatic energy eigenvalues of H 2 + are computed for complex values of the internuclear distance R. The infinite number of bound-state eigenenergies are represented by a function ε(R) that is single valued on a multisheeted Riemann surface. A region is found where ε(R) and the corresponding eigenfunctions exhibit harmonic-oscillator structure characteristic of electron motion on a potential saddle. The Schroedinger equation is solved in the adiabatic approximation along a path in the complex R plane to compute ionization cross sections. The cross section thus obtained joins the Wannier threshold region with the keV energy region, but the exponent near the ionization threshold disagrees with well-accepted values. Accepted values are obtained when a lowest-order diabatic correction is employed, indicating that adiabatic approximations do not give the correct zero velocity limit for ionization cross sections. Semiclassical eigenvalues for general top-of-barrier motion are given and the theory is applied to the ionization of atomic hydrogen by electron impact. The theory with a first diabatic correction gives the Wannier threshold law even for this case

  2. Scaling-Up Quantum Heat Engines Efficiently via Shortcuts to Adiabaticity

    Directory of Open Access Journals (Sweden)

    Mathieu Beau

    2016-04-01

    Full Text Available The finite-time operation of a quantum heat engine that uses a single particle as a working medium generally increases the output power at the expense of inducing friction that lowers the cycle efficiency. We propose to scale up a quantum heat engine utilizing a many-particle working medium in combination with the use of shortcuts to adiabaticity to boost the nonadiabatic performance by eliminating quantum friction and reducing the cycle time. To this end, we first analyze the finite-time thermodynamics of a quantum Otto cycle implemented with a quantum fluid confined in a time-dependent harmonic trap. We show that nonadiabatic effects can be controlled and tailored to match the adiabatic performance using a variety of shortcuts to adiabaticity. As a result, the nonadiabatic dynamics of the scaled-up many-particle quantum heat engine exhibits no friction, and the cycle can be run at maximum efficiency with a tunable output power. We demonstrate our results with a working medium consisting of particles with inverse-square pairwise interactions that includes non-interacting and hard-core bosons as limiting cases.

  3. Physical explosion analysis in heat exchanger network design

    Science.gov (United States)

    Pasha, M.; Zaini, D.; Shariff, A. M.

    2016-06-01

    The failure of shell and tube heat exchangers is being extensively experienced by the chemical process industries. This failure can create a loss of production for long time duration. Moreover, loss of containment through heat exchanger could potentially lead to a credible event such as fire, explosion and toxic release. There is a need to analyse the possible worst case effect originated from the loss of containment of the heat exchanger at the early design stage. Physical explosion analysis during the heat exchanger network design is presented in this work. Baker and Prugh explosion models are deployed for assessing the explosion effect. Microsoft Excel integrated with process design simulator through object linking and embedded (OLE) automation for this analysis. Aspen HYSYS V (8.0) used as a simulation platform in this work. A typical heat exchanger network of steam reforming and shift conversion process was presented as a case study. It is investigated from this analysis that overpressure generated from the physical explosion of each heat exchanger can be estimated in a more precise manner by using Prugh model. The present work could potentially assist the design engineer to identify the critical heat exchanger in the network at the preliminary design stage.

  4. A simple dynamic rising nuclear cloud based model of ground radioactive fallout for atmospheric nuclear explosion

    International Nuclear Information System (INIS)

    Zheng Yi

    2008-01-01

    A simple dynamic rising nuclear cloud based model for atmospheric nuclear explosion radioactive prediction was presented. The deposition of particles and initial cloud radius changing with time before the cloud stabilization was considered. Large-scale relative diffusion theory was used after cloud stabilization. The model was considered reasonable and dependable in comparison with four U.S. nuclear test cases and DELFIC model results. (authors)

  5. Inelastic processes in seismic wave generation by underground explosions

    Energy Technology Data Exchange (ETDEWEB)

    Rodean, H.C.

    1980-08-01

    Theories, computer calculations, and measurements of spherical stress waves from explosions are described and compared, with emphasis on the transition from inelastic to almost-elastic relations between stress and strain. Two aspects of nonspherical explosion geometry are considered: tectonic strain release and surface spall. Tectonic strain release affects the generation of surface waves; spall closure may also. The reduced-displacement potential is a common solution (the equivalent elastic source) of the forward and inverse problems, assuming a spherical source. Measured reduced-displacement potentials are compared with potentials calculated as solutions of the direct and inverse problems; there are significant differences between the results of the two types of calculations and between calculations and measurements. The simple spherical model of an explosion is not sufficient to account for observations of explosions over wide ranges of depth and yield. The explosion environment can have a large effect on explosion detection and yield estimation. The best sets of seismic observations for use in developing discrimination techniques are for high-magnitude high-yield explosions; the identification problem is most difficult for low-magnitude low-yield explosions. Most of the presently available explosion data (time, medium, depth, yield, etc.) are for explosions in a few media at the Nevada Test Site; some key questions concerning magnitude vs yield and m/sub b/ vs M/sub s/ relations can be answered only by data for explosions in other media at other locations.

  6. Inelastic processes in seismic wave generation by underground explosions

    International Nuclear Information System (INIS)

    Rodean, H.C.

    1980-01-01

    Theories, computer calculations, and measurements of spherical stress waves from explosions are described and compared, with emphasis on the transition from inelastic to almost-elastic relations between stress and strain. Two aspects of nonspherical explosion geometry are considered: tectonic strain release and surface spall. Tectonic strain release affects the generation of surface waves; spall closure may also. The reduced-displacement potential is a common solution (the equivalent elastic source) of the forward and inverse problems, assuming a spherical source. Measured reduced-displacement potentials are compared with potentials calculated as solutions of the direct and inverse problems; there are significant differences between the results of the two types of calculations and between calculations and measurements. The simple spherical model of an explosion is not sufficient to account for observations of explosions over wide ranges of depth and yield. The explosion environment can have a large effect on explosion detection and yield estimation. The best sets of seismic observations for use in developing discrimination techniques are for high-magnitude high-yield explosions; the identification problem is most difficult for low-magnitude low-yield explosions. Most of the presently available explosion data (time, medium, depth, yield, etc.) are for explosions in a few media at the Nevada Test Site; some key questions concerning magnitude vs yield and m/sub b/ vs M/sub s/ relations can be answered only by data for explosions in other media at other locations

  7. Incorporating damage mechanics into explosion simulation models

    International Nuclear Information System (INIS)

    Sammis, C.G.

    1993-01-01

    The source region of an underground explosion is commonly modeled as a nested series of shells. In the innermost open-quotes hydrodynamic regimeclose quotes pressures and temperatures are sufficiently high that the rock deforms as a fluid and may be described using a PVT equation of state. Just beyond the hydrodynamic regime, is the open-quotes non-linear regimeclose quotes in which the rock has shear strength but the deformation is nonlinear. This regime extends out to the open-quotes elastic radiusclose quotes beyond which the deformation is linear. In this paper, we develop a model for the non-linear regime in crystalline source rock where the nonlinearity is mostly due to fractures. We divide the non-linear regime into a open-quotes damage regimeclose quotes in which the stresses are sufficiently high to nucleate new fractures from preexisting ones and a open-quotes crack-slidingclose quotes regime where motion on preexisting cracks produces amplitude dependent attenuation and other non-linear effects, but no new cracks are nucleated. The boundary between these two regimes is called the open-quotes damage radius.close quotes The micromechanical damage mechanics recently developed by Ashby and Sammis (1990) is used to write an analytic expression for the damage radius in terms of the initial fracture spectrum of the source rock, and to develop an algorithm which may be used to incorporate damage mechanics into computer source models for the damage regime. Effects of water saturation and loading rate are also discussed

  8. A many-particle adiabatic invariant of strongly magnetized pure electron plasmas

    International Nuclear Information System (INIS)

    Hjorth, P.G.

    1988-01-01

    A pure electron plasma is said to be strongly magnetized if the cyclotron radius of the electrons is much smaller than the classical distance of closest approach. In this parameter regime a many-particle adiabatic invariant constrains the collisional dynamics. For the case of a uniform magnetic field, the adiabatic invariant is the total kinetic energy associated with the electron velocity components that are perpendicular to the magnetic field (i.e., Σ j mv 2 j perpendicular/2). Were the adiabatic invariant an exact constant of the motion, no exchange of energy would be possible between the parallel and the perpendicular degrees of freedom, and the plasma could develop and maintain two different temperatures T parallel and T perpendicular. An adiabatic invariant, however, is not strictly conserved. In the present case, each collision produces an exponentially small exchange of energy between the parallel and the perpendicular degrees of freedom, and these act cumulatively in such a way that T parallel and T perpendicular eventually relax to a common value. The rate of equilibrium is calculated, both in the case where the collisions are described by classical mechanics and in the case where the collisions are described by quantum mechanics, the two calculations giving essentially the same result. A molecular dynamics simulation has been carried out, verifying the existence of this unusual invariant, and verifying the theoretically predicted rate equation

  9. Seismic coupling of nuclear explosions

    International Nuclear Information System (INIS)

    Larson, D.B.

    1989-01-01

    The new Giant Magnet Experimental Facility employing digital recording of explosion induced motion has been constructed and successfully tested. Particle velocity and piezoresistance gage responses can be measured simultaneously thus providing the capability for determining the multi-component stress-strain history in the test material. This capability provides the information necessary for validation of computer models used in simulation of nuclear underground testing, chemical explosion testing, dynamic structural response, earth penetration response, and etc. This report discusses fully coupled and cavity decoupled explosions of the same energy (0.622 kJ) were carried out as experiments to study wave propagation and attenuation in polymethylmethacrylate (PMMA). These experiments produced particle velocity time histories at strains from 2 x 10 -3 to as low as 5.8 x 10 -6 . Other experiments in PMMA, reported recently by Stout and Larson 8 provide additional particle velocity data to strains of 10 -1

  10. Adiabatic pipelining: a key to ternary computing with quantum dots

    Science.gov (United States)

    Pečar, P.; Ramšak, A.; Zimic, N.; Mraz, M.; Lebar Bajec, I.

    2008-12-01

    The quantum-dot cellular automaton (QCA), a processing platform based on interacting quantum dots, was introduced by Lent in the mid-1990s. What followed was an exhilarating period with the development of the line, the functionally complete set of logic functions, as well as more complex processing structures, however all in the realm of binary logic. Regardless of these achievements, it has to be acknowledged that the use of binary logic is in computing systems mainly the end result of the technological limitations, which the designers had to cope with in the early days of their design. The first advancement of QCAs to multi-valued (ternary) processing was performed by Lebar Bajec et al, with the argument that processing platforms of the future should not disregard the clear advantages of multi-valued logic. Some of the elementary ternary QCAs, necessary for the construction of more complex processing entities, however, lead to a remarkable increase in size when compared to their binary counterparts. This somewhat negates the advantages gained by entering the ternary computing domain. As it turned out, even the binary QCA had its initial hiccups, which have been solved by the introduction of adiabatic switching and the application of adiabatic pipeline approaches. We present here a study that introduces adiabatic switching into the ternary QCA and employs the adiabatic pipeline approach to successfully solve the issues of elementary ternary QCAs. What is more, the ternary QCAs presented here are sizewise comparable to binary QCAs. This in our view might serve towards their faster adoption.

  11. Adiabatic pipelining: a key to ternary computing with quantum dots

    International Nuclear Information System (INIS)

    Pecar, P; Zimic, N; Mraz, M; Lebar Bajec, I; Ramsak, A

    2008-01-01

    The quantum-dot cellular automaton (QCA), a processing platform based on interacting quantum dots, was introduced by Lent in the mid-1990s. What followed was an exhilarating period with the development of the line, the functionally complete set of logic functions, as well as more complex processing structures, however all in the realm of binary logic. Regardless of these achievements, it has to be acknowledged that the use of binary logic is in computing systems mainly the end result of the technological limitations, which the designers had to cope with in the early days of their design. The first advancement of QCAs to multi-valued (ternary) processing was performed by Lebar Bajec et al, with the argument that processing platforms of the future should not disregard the clear advantages of multi-valued logic. Some of the elementary ternary QCAs, necessary for the construction of more complex processing entities, however, lead to a remarkable increase in size when compared to their binary counterparts. This somewhat negates the advantages gained by entering the ternary computing domain. As it turned out, even the binary QCA had its initial hiccups, which have been solved by the introduction of adiabatic switching and the application of adiabatic pipeline approaches. We present here a study that introduces adiabatic switching into the ternary QCA and employs the adiabatic pipeline approach to successfully solve the issues of elementary ternary QCAs. What is more, the ternary QCAs presented here are sizewise comparable to binary QCAs. This in our view might serve towards their faster adoption.

  12. Adiabatic pipelining: a key to ternary computing with quantum dots.

    Science.gov (United States)

    Pečar, P; Ramšak, A; Zimic, N; Mraz, M; Lebar Bajec, I

    2008-12-10

    The quantum-dot cellular automaton (QCA), a processing platform based on interacting quantum dots, was introduced by Lent in the mid-1990s. What followed was an exhilarating period with the development of the line, the functionally complete set of logic functions, as well as more complex processing structures, however all in the realm of binary logic. Regardless of these achievements, it has to be acknowledged that the use of binary logic is in computing systems mainly the end result of the technological limitations, which the designers had to cope with in the early days of their design. The first advancement of QCAs to multi-valued (ternary) processing was performed by Lebar Bajec et al, with the argument that processing platforms of the future should not disregard the clear advantages of multi-valued logic. Some of the elementary ternary QCAs, necessary for the construction of more complex processing entities, however, lead to a remarkable increase in size when compared to their binary counterparts. This somewhat negates the advantages gained by entering the ternary computing domain. As it turned out, even the binary QCA had its initial hiccups, which have been solved by the introduction of adiabatic switching and the application of adiabatic pipeline approaches. We present here a study that introduces adiabatic switching into the ternary QCA and employs the adiabatic pipeline approach to successfully solve the issues of elementary ternary QCAs. What is more, the ternary QCAs presented here are sizewise comparable to binary QCAs. This in our view might serve towards their faster adoption.

  13. High-order shock-fitted detonation propagation in high explosives

    Science.gov (United States)

    Romick, Christopher M.; Aslam, Tariq D.

    2017-03-01

    A highly accurate numerical shock and material interface fitting scheme composed of fifth-order spatial and third- or fifth-order temporal discretizations is applied to the two-dimensional reactive Euler equations in both slab and axisymmetric geometries. High rates of convergence are not typically possible with shock-capturing methods as the Taylor series analysis breaks down in the vicinity of discontinuities. Furthermore, for typical high explosive (HE) simulations, the effects of material interfaces at the charge boundary can also cause significant computational errors. Fitting a computational boundary to both the shock front and material interface (i.e. streamline) alleviates the computational errors associated with captured shocks and thus opens up the possibility of high rates of convergence for multi-dimensional shock and detonation flows. Several verification tests, including a Sedov blast wave, a Zel'dovich-von Neumann-Döring (ZND) detonation wave, and Taylor-Maccoll supersonic flow over a cone, are utilized to demonstrate high rates of convergence to nontrivial shock and reaction flows. Comparisons to previously published shock-capturing multi-dimensional detonations in a polytropic fluid with a constant adiabatic exponent (PF-CAE) are made, demonstrating significantly lower computational error for the present shock and material interface fitting method. For an error on the order of 10 m /s, which is similar to that observed in experiments, shock-fitting offers a computational savings on the order of 1000. In addition, the behavior of the detonation phase speed is examined for several slab widths to evaluate the detonation performance of PBX 9501 while utilizing the Wescott-Stewart-Davis (WSD) model, which is commonly used in HE modeling. It is found that the thickness effect curve resulting from this equation of state and reaction model using published values is dramatically more steep than observed in recent experiments. Utilizing the present fitting

  14. Multi-objective optimization of Stirling engine using non-ideal adiabatic method

    International Nuclear Information System (INIS)

    Toghyani, Somayeh; Kasaeian, Alibakhsh; Ahmadi, Mohammad H.

    2014-01-01

    Highlights: • A multi-objective optimization is carried out for a Stirling engine. • The methods of TOPSIS, Fuzzy, and LINMAP are compared with each other in aspect of optimization. • The results are compared with the previous works for checking the model improvement. • A proper improvement is observed using TOPSIS when comparing with the others. - Abstract: In the recent years, remarkable attention is drawn to Stirling engine due to noticeable advantages, for instance a lot of resources such as biomass, fossil fuels and solar energy can be applied as heat source. Great numbers of studies are conducted on Stirling engines and non-ideal adiabatic method is one of them. In the present study, the efficiency and the power loss due to pressure drop into the heat exchangers are optimized for a Stirling system using non-ideal adiabatic analysis and the second-version Non-dominated Sorting Genetic Algorithm. The optimized answers are chosen from the results using three decision-making methods. The applied methods were compared at last and the best results were obtained for the technique for order preference by similarity to ideal solution decision making method

  15. Studies of the laser-induced fluorescence of explosives and explosive compositions.

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Philip Joseph, Jr. (,; .); Thorne, Lawrence R.; Phifer, Carol Celeste; Parmeter, John Ethan; Schmitt, Randal L.

    2006-10-01

    Continuing use of explosives by terrorists throughout the world has led to great interest in explosives detection technology, especially in technologies that have potential for standoff detection. This LDRD was undertaken in order to investigate the possible detection of explosive particulates at safe standoff distances in an attempt to identify vehicles that might contain large vehicle bombs (LVBs). The explosives investigated have included the common homogeneous or molecular explosives, 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclonite or hexogen (RDX), octogen (HMX), and the heterogeneous explosive, ammonium nitrate/fuel oil (ANFO), and its components. We have investigated standard excited/dispersed fluorescence, laser-excited prompt and delayed dispersed fluorescence using excitation wavelengths of 266 and 355 nm, the effects of polarization of the laser excitation light, and fluorescence imaging microscopy using 365- and 470-nm excitation. The four nitro-based, homogeneous explosives (TNT, PETN, RDX, and HMX) exhibit virtually no native fluorescence, but do exhibit quenching effects of varying magnitude when adsorbed on fluorescing surfaces. Ammonium nitrate and fuel oil mixtures fluoresce primarily due to the fuel oil, and, in some cases, due to the presence of hydrophobic coatings on ammonium nitrate prill or impurities in the ammonium nitrate itself. Pure ammonium nitrate shows no detectable fluorescence. These results are of scientific interest, but they provide little hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability.

  16. The digital radiographic and computed tomography imaging of two types of explosive devices

    International Nuclear Information System (INIS)

    Galiano Riveros, Eduardo

    2002-01-01

    Two well-established medical imaging methods, digital radiography (DR) and computed tomography (CT), were employed to obtain images of two types of explosive devices, model rocket engines and shotgun shells. The images were evaluated from an airport security perspective. In terms of geometrical shape, the detection probability of the explosive devices appears to be higher with DR imaging, but in terms of the actual explosive compounds in the devices, CT appears to offer a higher detection probability. DR imaging offers a low detection probability for the explosive powder in the shotgun shells, but a rather significant detection probability for the explosive propellant in the model rocket engines

  17. Modelling of turbulence and combustion for simulation of gas explosions in complex geometries

    Energy Technology Data Exchange (ETDEWEB)

    Arntzen, Bjoern Johan

    1998-12-31

    This thesis analyses and presents new models for turbulent reactive flows for CFD (Computational Fluid Dynamics) simulation of gas explosions in complex geometries like offshore modules. The course of a gas explosion in a complex geometry is largely determined by the development of turbulence and the accompanying increased combustion rate. To be able to model the process it is necessary to use a CFD code as a starting point, provided with a suitable turbulence and combustion model. The modelling and calculations are done in a three-dimensional finite volume CFD code, where complex geometries are represented by a porosity concept, which gives porosity on the grid cell faces, depending on what is inside the cell. The turbulent flow field is modelled with a k-{epsilon} turbulence model. Subgrid models are used for production of turbulence from geometry not fully resolved on the grid. Results from laser doppler anemometry measurements around obstructions in steady and transient flows have been analysed and the turbulence models have been improved to handle transient, subgrid and reactive flows. The combustion is modelled with a burning velocity model and a flame model which incorporates the burning velocity into the code. Two different flame models have been developed: SIF (Simple Interface Flame model), which treats the flame as an interface between reactants and products, and the {beta}-model where the reaction zone is resolved with about three grid cells. The flame normally starts with a quasi laminar burning velocity, due to flame instabilities, modelled as a function of flame radius and laminar burning velocity. As the flow field becomes turbulent, the flame uses a turbulent burning velocity model based on experimental data and dependent on turbulence parameters and laminar burning velocity. The laminar burning velocity is modelled as a function of gas mixture, equivalence ratio, pressure and temperature in reactant. Simulations agree well with experiments. 139

  18. High beta lasing in micropillar cavities with adiabatic layer design

    DEFF Research Database (Denmark)

    Lermer, M.; Gregersen, Niels; Lorke, M.

    2013-01-01

    We report on lasing in optically pumped adiabatic micropillar cavities, based on the AlAs/GaAs material system. A detailed study of the threshold pump power and the spontaneous emission β factor in the lasing regime for different diameters dc is presented. We demonstrate a reduction of the thresh...... of the threshold pump power by over 2 orders of magnitude from dc = 2.25 μm down to 0.95 μm. Lasing with β factors exceeding 0.5 shows that adiabatic micropillars are operating deeply in the cavity quantum electrodynamics regime....

  19. A Parameter Study of Large Fast Reactor Nuclear Explosion Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Wiesel, J R

    1969-02-15

    An IBM-code EEM (Explosive Excursion Model) has been developed for calculating the energy releases associated with the explosive disassembly of a large fast reactor following a superprompt critical condition. The assumed failure chain of events and the possible core collapse following a fuel meltdown give the input data and initial conditions, the most important of which is the reactivity insertion rate at the moment of the explosive core disassembly. The dependence of the energy releases on the reactivity insertion rate, the Doppler reactivity feedback, the power form factor and the core size have been studied. The model enables a quick estimation of conservative values of the destructive mechanical energy releases following a nuclear explosion and gives suggestions as to how to reduce or even avoid such excursions.

  20. A Parameter Study of Large Fast Reactor Nuclear Explosion Accidents

    International Nuclear Information System (INIS)

    Wiesel, J.R.

    1969-02-01

    An IBM-code EEM (Explosive Excursion Model) has been developed for calculating the energy releases associated with the explosive disassembly of a large fast reactor following a superprompt critical condition. The assumed failure chain of events and the possible core collapse following a fuel meltdown give the input data and initial conditions, the most important of which is the reactivity insertion rate at the moment of the explosive core disassembly. The dependence of the energy releases on the reactivity insertion rate, the Doppler reactivity feedback, the power form factor and the core size have been studied. The model enables a quick estimation of conservative values of the destructive mechanical energy releases following a nuclear explosion and gives suggestions as to how to reduce or even avoid such excursions

  1. Error suppression and error correction in adiabatic quantum computation: non-equilibrium dynamics

    International Nuclear Information System (INIS)

    Sarovar, Mohan; Young, Kevin C

    2013-01-01

    While adiabatic quantum computing (AQC) has some robustness to noise and decoherence, it is widely believed that encoding, error suppression and error correction will be required to scale AQC to large problem sizes. Previous works have established at least two different techniques for error suppression in AQC. In this paper we derive a model for describing the dynamics of encoded AQC and show that previous constructions for error suppression can be unified with this dynamical model. In addition, the model clarifies the mechanisms of error suppression and allows the identification of its weaknesses. In the second half of the paper, we utilize our description of non-equilibrium dynamics in encoded AQC to construct methods for error correction in AQC by cooling local degrees of freedom (qubits). While this is shown to be possible in principle, we also identify the key challenge to this approach: the requirement of high-weight Hamiltonians. Finally, we use our dynamical model to perform a simplified thermal stability analysis of concatenated-stabilizer-code encoded many-body systems for AQC or quantum memories. This work is a companion paper to ‘Error suppression and error correction in adiabatic quantum computation: techniques and challenges (2013 Phys. Rev. X 3 041013)’, which provides a quantum information perspective on the techniques and limitations of error suppression and correction in AQC. In this paper we couch the same results within a dynamical framework, which allows for a detailed analysis of the non-equilibrium dynamics of error suppression and correction in encoded AQC. (paper)

  2. Analysis of supercritical vapor explosions using thermal detonation wave theory

    Energy Technology Data Exchange (ETDEWEB)

    Shamoun, B.I.; Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    The interaction of certain materials such as Al{sub 2}O{sub 3} with water results in vapor explosions with very high (supercritical) pressures and propagation velocities. A quasi-steady state analysis of supercritical detonation in one-dimensional multiphase flow was applied to analyze experimental data of the KROTOS (26-30) set of experiments conducted at the Joint Research Center at Ispra, Italy. In this work we have applied a new method of solution which allows for partial fragmentation of the fuel in the shock adiabatic thermodynamic model. This method uses known experiment values of the shock pressure and propagation velocity to estimate the initial mixing conditions of the experiment. The fuel and coolant were both considered compressible in this analysis. In KROTOS 26, 28, 29, and 30 the measured values of the shock pressure by the experiment were found to be higher than 25, 50, 100, and 100 Mpa respectively. Using the above data for the wave velocity and our best estimate for the values of the pressure, the predicted minimum values of the fragmented mass of the fuel were found to be 0.026. 0.04, 0.057, and 0.068 kg respectively. The predicted values of the work output corresponding to the above fragmented masses of the fuel were found to be 40, 84, 126, and 150 kJ respectively, with predicted initial void fractions of 112%, 12.5%, 8%, and 6% respectively.

  3. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Science.gov (United States)

    2011-10-19

    ... slurry and water gel explosives. Blasting caps. Blasting gelatin. Blasting powder. BTNEC [bis.... Esters of nitro-substituted alcohols. Ethyl-tetryl. Explosive conitrates. Explosive gelatins. Explosive... silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G Gelatinized...

  4. Research on Initiation Sensitivity of Solid Explosive and Planer Initiation System

    Directory of Open Access Journals (Sweden)

    N Matsuo

    2016-09-01

    Full Text Available Firstly, recently, there are a lot of techniques being demanded for complex process, various explosive initiation method and highly accurate control of detonation are needed. In this research, the metal foil explosion using high current is focused attention on the method to obtain linear or planate initiation easily, and the main evaluation of metal foil explosion to initiate explosive was conducted. The explosion power was evaluated by observing optically the underwater shock wave generated from the metal foil explosion. Secondly, in high energy explosive processing, there are several applications, such as shock compaction, explosive welding, food processing and explosive forming. In these explosive applications, a high sensitive explosive has been mainly used. The high sensitive explosive is so dangerous, since it can lead to explosion suddenly. So, for developing explosives, the safety is the most important thing as well as low manufacturing cost and explosive characteristics. In this work, we have focused on the initiation sensitivity of a solid explosive and performed numerical analysis of sympathetic detonation. The numerical analysis is calculated by LS-DYNA 3D (commercial code. To understand the initiation reaction of an explosive, Lee-Tarver equation was used and impact detonation process was analyzed by ALE code. Configuration of simulation model is a quarter of circular cylinder. The donor type of explosive (SEP was used as initiation explosive. When the donor explosive is exploded, a shock wave is generated and it propagates into PMMA, air and metallic layers in order. During passing through the layers, the shock wave is attenuated and finally, it has influence on the acceptor explosive, Comp. B. Here, we evaluate the initiation of acceptor explosive and discuss about detonation pressure, reactive rate of acceptor explosive and attenuation of impact pressure.

  5. Shock-induced explosive chemistry in a deterministic sample configuration.

    Energy Technology Data Exchange (ETDEWEB)

    Stuecker, John Nicholas; Castaneda, Jaime N.; Cesarano, Joseph, III (,; ); Trott, Wayne Merle; Baer, Melvin R.; Tappan, Alexander Smith

    2005-10-01

    Explosive initiation and energy release have been studied in two sample geometries designed to minimize stochastic behavior in shock-loading experiments. These sample concepts include a design with explosive material occupying the hole locations of a close-packed bed of inert spheres and a design that utilizes infiltration of a liquid explosive into a well-defined inert matrix. Wave profiles transmitted by these samples in gas-gun impact experiments have been characterized by both velocity interferometry diagnostics and three-dimensional numerical simulations. Highly organized wave structures associated with the characteristic length scales of the deterministic samples have been observed. Initiation and reaction growth in an inert matrix filled with sensitized nitromethane (a homogeneous explosive material) result in wave profiles similar to those observed with heterogeneous explosives. Comparison of experimental and numerical results indicates that energetic material studies in deterministic sample geometries can provide an important new tool for validation of models of energy release in numerical simulations of explosive initiation and performance.

  6. Modelling the dynamics and hazards of explosive eruptions: Where we are now, and confronting the next challenges (Sergey Soloviev Medal Lecture)

    Science.gov (United States)

    Neri, Augusto

    2017-04-01

    Understanding of explosive eruption dynamics and assessment of their hazards continue to represent challenging issues to the present-day volcanology community. This is largely due to the complex and diverse nature of the phenomena, and the variability and unpredictability of volcanic processes. Nevertheless, important and continuing progress has been made in the last few decades in understanding fundamental processes and in forecasting the occurrences of these phenomena, thanks to significant advances in field, experimental and theoretical modeling investigations. For over four decades, for example, volcanologists have made major progress in the description of the nature of explosive eruptions, considerably aided by the development, improvement, and application of physical-mathematical models. Integral steady-state homogeneous flow models were first used to investigate the different controlling mechanisms and to infer the genesis and evolution of the phenomena. Through continuous improvements and quantum-leap developments, a variety of transient, 3D, multiphase flow models of volcanic phenomena now can implement state-of-the-art formulations of the underlying physics, new-generation analytical and experimental data, as well as high-performance computational techniques. These numerical models have proved to be able to provide key insights in the understanding of the dynamics of explosive eruptions (e.g. convective plumes, collapsing columns, pyroclastic density currents, short-lived explosions, etc.), as well as to represent a valuable tool in the quantification of potential eruptive scenarios and associated hazards. Simplified models based on a reduction of the system complexity have been also proved useful, combined with Monte Carlo and statistical methods, to generate quantitative probabilistic hazard maps at different space and time scales, some including the quantification of important sources of uncertainty. Nevertheless, the development of physical models

  7. Adiabatic theorem for the time-dependent wave operator

    International Nuclear Information System (INIS)

    Viennot, David; Jolicard, Georges; Killingbeck, John P.; Perrin, Marie-Yvonne

    2005-01-01

    The application of time-dependent wave operator theory to the development of a quantum adiabatic perturbation theory is treated both theoretically and numerically, with emphasis on the description of field-matter interactions which involve short laser pulses. It is first shown that the adiabatic limit of the time-dependent wave operator corresponds to a succession of instantaneous static Bloch wave operators. Wave operator theory is then shown to be compatible with the two-time Floquet theory of light-matter interaction, thus allowing the application of Floquet theory to cases which require the use of a degenerate active space. A numerical study of some problems shows that the perturbation strength associated with nonadiabatic processes can be reduced by using multidimensional active spaces and illustrates the capacity of the wave operator approach to produce a quasiadiabatic treatment of a nominally nonadiabatic Floquet dynamical system

  8. Modeling of composite synthesis in conditions of controlled thermal explosion

    Science.gov (United States)

    Kukta, Yaroslav; Knyazeva, Anna

    2017-12-01

    The paper proposes the model for the titanium-based composite synthesis from powders of titanium and carbon of non-stoichiometric composition. The model takes into account the mixture heating from chamber walls, the dependence of liquidus and solidus temperatures on the composition of reacting mixture and the formation of possible irreversible phases. The reaction retardation by the reaction product is taken into consideration in kinetic laws. As an example, the results of temperature and conversion level calculation are presented for the system Ti-C with the summary reaction for different temperatures of chamber walls heating. It was revealed that the reaction retardation being the reaction product can be the cause of incomplete conversion in the thermal explosion conditions. Non-stoichiometric composition leads to the conditions of degenerated mode when some additional heating is necessary to complete the reaction.

  9. Nanosecond laser ablation of target Al in a gaseous medium: explosive boiling

    Science.gov (United States)

    Mazhukin, V. I.; Mazhukin, A. V.; Demin, M. M.; Shapranov, A. V.

    2018-03-01

    An approximate mathematical description of the processes of homogeneous nucleation and homogeneous evaporation (explosive boiling) of a metal target (Al) under the influence of ns laser radiation is proposed in the framework of the hydrodynamic model. Within the continuum approach, a multi-phase, multi-front hydrodynamic model and a computational algorithm are designed to simulate nanosecond laser ablation of the metal targets immersed in gaseous media. The proposed approach is intended for modeling and detailed analysis of the mechanisms of heterogeneous and homogeneous evaporation and their interaction with each other. It is shown that the proposed model and computational algorithm allow modeling of interrelated mechanisms of heterogeneous and homogeneous evaporation of metals, manifested in the form of pulsating explosive boiling. Modeling has shown that explosive evaporation in metals is due to the presence of a near-surface temperature maximum. It has been established that in nanosecond pulsed laser ablation, such exposure regimes can be implemented in which phase explosion is the main mechanism of material removal.

  10. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Science.gov (United States)

    2012-09-20

    ... sensitive slurry and water gel explosives. Blasting caps. Blasting gelatin. Blasting powder. BTNEC [bis.... Esters of nitro-substituted alcohols. Ethyl-tetryl. Explosive conitrates. Explosive gelatins. Explosive.... Fulminate of silver. Fulminating gold. Fulminating mercury. Fulminating platinum. Fulminating silver. G...

  11. Analysis of ventilation systems subjected to explosive transients: far-field analysis

    International Nuclear Information System (INIS)

    Tang, P.K.; Andrae, R.W.; Bolstad, J.W.; Duerre, K.H.; Gregory, W.S.

    1981-11-01

    Progress in developing a far-field explosion simulation computer code is outlined. The term far-field implies that this computer code is suitable for modeling explosive transients in ventilation systems that are far removed from the explosive event and are rather insensitive to the particular characteristics of the explosive event. This type of analysis is useful when little detailed information is available and the explosive event is described parametrically. The code retains all the features of the TVENT code and allows completely compressible flow with inertia and choking effects. Problems that illustrate the capabilities and limitations of the code are described

  12. Nondestructive test for assembly relationship of initiating explosive device

    International Nuclear Information System (INIS)

    Wang Xiangang; Zhang Chaozong; Guo Zhiping

    2009-01-01

    A 3D computed tomography (CT) method to inspect assembly relationship of initiating explosive device and to nondestructively evaluate assembly relationship by building geometric model from CT images was described. The experiment result proves that this method accurately inspects assembly relationship of initiating explosive device. (authors)

  13. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed......Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...

  14. Model testing of a 10-kg high explosive blast attenuation maze

    International Nuclear Information System (INIS)

    Bacigalupi, C.M.; Burton, W.A.

    1981-01-01

    The basement area of the proposed High Explosive Applications Facility (HEAF) at the Lawrence Livermore National Laboratory includes 10-kg HE assembly and process cells, and a 10-kg corridor for the transport of up to 10 kg of HE from the receiving dock to the cells and to the experimental firing tanks. Previous model experiments developed a process cell-maze configuration that attenuated the effects of an accidental 10-kg detonation to acceptable levels (maximum of 10 to 11 psi reflected). This document reports 1/8-scale model tests conducted to confirm the maze design and to determine the blast pressures in adjacent areas in the final HEAF building configuration. In addition, pressure/time information was obtained at selected points in the model expansion chamber to provide the architect-engineer with information for structural design

  15. The Effect of Specimen Size on the Results of Concrete Adiabatic Temperature Rise Test with Commercially Available Equipment

    Directory of Open Access Journals (Sweden)

    Byung Jae Lee

    2014-12-01

    Full Text Available In this study, adiabatic temperature rise tests depending on binder type and adiabatic specimen volume were performed, and the maximum adiabatic temperature rises and the reaction factors for each mix proportion were analyzed and suggested. The results indicated that the early strength low heat blended cement mixture had the lowest maximum adiabatic temperature rise (Q∞ and the ternary blended cement mixture had the lowest reaction factor (r. Also, Q and r varied depending on the adiabatic specimen volume even when the tests were conducted with a calorimeter, which satisfies the recommendations for adiabatic conditions. Test results show a correlation: the measurements from the 50 L specimens were consistently higher than those from the 6 L specimens. However, the Q∞ and r values of the 30 L specimen were similar to those of the 50 L specimen. Based on the above correlation, the adiabatic temperature rise of the 50 L specimen could be predicted using the results of the 6 L and 30 L specimens. Therefore, it is thought that this correlation can be used for on-site concrete quality control and basic research.

  16. The Effect of Specimen Size on the Results of Concrete Adiabatic Temperature Rise Test with Commercially Available Equipment.

    Science.gov (United States)

    Lee, Byung Jae; Bang, Jin Wook; Shin, Kyung Joon; Kim, Yun Yong

    2014-12-08

    In this study, adiabatic temperature rise tests depending on binder type and adiabatic specimen volume were performed, and the maximum adiabatic temperature rises and the reaction factors for each mix proportion were analyzed and suggested. The results indicated that the early strength low heat blended cement mixture had the lowest maximum adiabatic temperature rise ( Q ∞ ) and the ternary blended cement mixture had the lowest reaction factor ( r ). Also, Q and r varied depending on the adiabatic specimen volume even when the tests were conducted with a calorimeter, which satisfies the recommendations for adiabatic conditions. Test results show a correlation: the measurements from the 50 L specimens were consistently higher than those from the 6 L specimens. However, the Q ∞ and r values of the 30 L specimen were similar to those of the 50 L specimen. Based on the above correlation, the adiabatic temperature rise of the 50 L specimen could be predicted using the results of the 6 L and 30 L specimens. Therefore, it is thought that this correlation can be used for on-site concrete quality control and basic research.

  17. Analysis of adiabatic transfer in cavity quantum electrodynamics

    Indian Academy of Sciences (India)

    adiabatic transfer process through the 'dark state' by a slow variation of the control laser intensity. ... control field of Rabi frequency C(t) transfers one photon in the cavity mode to a long- .... It gives an approximate statistical description of the.

  18. Explosion localization and characterization via infrasound using numerical modeling

    Science.gov (United States)

    Fee, D.; Kim, K.; Iezzi, A. M.; Matoza, R. S.; Jolly, A. D.; De Angelis, S.; Diaz Moreno, A.; Szuberla, C.

    2017-12-01

    Numerous methods have been applied to locate, detect, and characterize volcanic and anthropogenic explosions using infrasound. Far-field localization techniques typically use back-azimuths from multiple arrays (triangulation) or Reverse Time Migration (RTM, or back-projection). At closer ranges, networks surrounding a source may use Time Difference of Arrival (TDOA), semblance, station-pair double difference, etc. However, at volcanoes and regions with topography or obstructions that block the direct path of sound, recent studies have shown that numerical modeling is necessary to provide an accurate source location. A heterogeneous and moving atmosphere (winds) may also affect the location. The time reversal mirror (TRM) application of Kim et al. (2015) back-propagates the wavefield using a Finite Difference Time Domain (FDTD) algorithm, with the source corresponding to the location of peak convergence. Although it provides high-resolution source localization and can account for complex wave propagation, TRM is computationally expensive and limited to individual events. Here we present a new technique, termed RTM-FDTD, which integrates TRM and FDTD. Travel time and transmission loss information is computed from each station to the entire potential source grid from 3-D Green's functions derived via FDTD. The wave energy is then back-projected and stacked at each grid point, with the maximum corresponding to the likely source. We apply our method to detect and characterize thousands of explosions from Yasur Volcano, Vanuatu and Etna Volcano, Italy, which both provide complex wave propagation and multiple source locations. We compare our results with those from more traditional methods (e.g. semblance), and suggest our method is preferred as it is computationally less expensive than TRM but still integrates numerical modeling. RTM-FDTD could be applied to volcanic other anthropogenic sources at a wide variety of ranges and scenarios. Kim, K., Lees, J.M., 2015. Imaging

  19. Underground nuclear explosions

    International Nuclear Information System (INIS)

    Higgins, Gary H.

    1970-01-01

    In the Third Plowshare Symposium, held in 1964, data from a number of nuclear explosions were presented. At that time the basic elements of the nuclear explosion appeared to be well understood and relationships for predicting the gross nuclear effects were presented. Since that time, additional work has been done and many of the concepts have been extended. For example, nuclear explosions have been conducted at greater depths and with much greater yields. The physical and chemical properties of the material in which the explosions occur have been more accurately measured and related to explosion effects. Interpretation of the new information seems to indicate that the earlier relationships are valid over the ranges of energy and depths for which data is available but that effects relating to cavity and chimney sizes or fracturing had been overestimated at great depths of burst and higher yields. (author)

  20. Underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, Gary H [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    In the Third Plowshare Symposium, held in 1964, data from a number of nuclear explosions were presented. At that time the basic elements of the nuclear explosion appeared to be well understood and relationships for predicting the gross nuclear effects were presented. Since that time, additional work has been done and many of the concepts have been extended. For example, nuclear explosions have been conducted at greater depths and with much greater yields. The physical and chemical properties of the material in which the explosions occur have been more accurately measured and related to explosion effects. Interpretation of the new information seems to indicate that the earlier relationships are valid over the ranges of energy and depths for which data is available but that effects relating to cavity and chimney sizes or fracturing had been overestimated at great depths of burst and higher yields. (author)

  1. Numerical computation of underwater explosions due to fuel-coolant interactions

    International Nuclear Information System (INIS)

    Lee, J.H.S.; Frost, D.L.; Knystautas, R.; Teodorczyk, A.; Ciccarelli, G.; Thibault, P.; Penrose, J.

    1989-03-01

    If coarse molten material is released into a coolant the possibility exists for a violent steam explosion. A detailed quantitative description of the processes involved in steam explosions is currently beyond the capabilities of the scientific community. However, a conservative estimate of the pressure transients resulting from a steam explosion can be obtained by studying the dynamics of the shock associated with the expansion of a high-pressure vapour bubble. In this study, the hydrodynamic equations governing the shock propagation of an expanding bubble were integrated numerically using the Flux Corrected Transport code. Simpler acoustic models based on experience with underwater explosions were also developed and used to estimate pressure transients and to calculate the peak pressures for benchmark cases. The results were found to be an order of magnitude higher than the corresponding pressures obtained using a complex model developed by Henry. A simplified version of the Henry model was developed by neglecting the complex description of the two-phase flow inside the ruptured tube and the arbitrarily assumed heat transfer and condensation rates. Results from the simplified model were found to be generally similar to, but had higher peak pressures than those obtained using the Henry model. It is concluded that the results produced by simple acoustic models, or by a simplified Henry model, are more conservative than the corresponding results obtained with the original Henry model

  2. Adiabatic tapered optical fiber fabrication in two step etching

    Science.gov (United States)

    Chenari, Z.; Latifi, H.; Ghamari, S.; Hashemi, R. S.; Doroodmand, F.

    2016-01-01

    A two-step etching method using HF acid and Buffered HF is proposed to fabricate adiabatic biconical optical fiber tapers. Due to the fact that the etching rate in second step is almost 3 times slower than the previous droplet etching method, terminating the fabrication process is controllable enough to achieve a desirable fiber diameter. By monitoring transmitted spectrum, final diameter and adiabaticity of tapers are deduced. Tapers with losses about 0.3 dB in air and 4.2 dB in water are produced. The biconical fiber taper fabricated using this method is used to excite whispering gallery modes (WGMs) on a microsphere surface in an aquatic environment. So that they are suitable to be used in applications like WGM biosensors.

  3. Assignment of Side-Chain Conformation Using Adiabatic Energy Mapping, Free Energy Perturbation, and Molecular Dynamic Simulations

    DEFF Research Database (Denmark)

    Frimurer, Thomas M.; Günther, Peter H.; Sørensen, Morten Dahl

    1999-01-01

    adiabatic mapping, conformational change, essentialdynamics, free energy simulations, Kunitz type inhibitor *ga3(VI)......adiabatic mapping, conformational change, essentialdynamics, free energy simulations, Kunitz type inhibitor *ga3(VI)...

  4. Steam explosion simulation code JASMINE v.3 user's guide

    International Nuclear Information System (INIS)

    Moriyama, Kiyofumi; Maruyama, Yu; Nakamura, Hideo

    2008-07-01

    A steam explosion occurs when hot liquid contacts with cold volatile liquid. In this phenomenon, fine fragmentation of the hot liquid causes extremely rapid heat transfer from the hot liquid to the cold volatile liquid, and explosive vaporization, bringing shock waves and destructive forces. The steam explosion due to the contact of the molten core material and coolant water during severe accidents of light water reactors has been regarded as a potential threat to the integrity of the containment vessel. We developed a mechanistic steam explosion simulation code, JASMINE, that is applicable to plant scale assessment of the steam explosion loads. This document, as a manual for users of JASMINE code, describes the models, numerical solution methods, and also some verification and example calculations, as well as practical instructions for input preparation and usage of the code. (author)

  5. High explosive programmed burn in the FLAG code

    Energy Technology Data Exchange (ETDEWEB)

    Mandell, D.; Burton, D.; Lund, C.

    1998-02-01

    The models used to calculate the programmed burn high-explosive lighting times for two- and three-dimensions in the FLAG code are described. FLAG uses an unstructured polyhedra grid. The calculations were compared to exact solutions for a square in two dimensions and for a cube in three dimensions. The maximum error was 3.95 percent in two dimensions and 4.84 percent in three dimensions. The high explosive lighting time model described has the advantage that only one cell at a time needs to be considered.

  6. Core-Collapse Supernovae: Explosion dynamics, neutrinos and gravitational waves

    OpenAIRE

    Müller, Bernhard; Janka, Hans-Thomas; Marek, Andreas; Hanke, Florian; Wongwathanarat, Annop; Müller, Ewald

    2011-01-01

    The quest for the supernova explosion mechanism has been one of the outstanding challenges in computational astrophysics for several decades. Simulations have now progressed to a stage at which the solution appears close and neutrino and gravitational wave signals from self-consistent explosion models are becoming available. Here we focus one of the recent advances in supernova modeling, the inclusion of general relativity in multi-dimensional neutrino hydrodynamics simulations, and present t...

  7. Inhomogeneous quasi-adiabatic driving of quantum critical dynamics in weakly disordered spin chains

    International Nuclear Information System (INIS)

    Rams, Marek M; Mohseni, Masoud; Campo, Adolfo del

    2016-01-01

    We introduce an inhomogeneous protocol to drive a weakly disordered quantum spin chain quasi-adiabatically across a quantum phase transition and minimize the residual energy of the final state. The number of spins that simultaneously reach the critical point is controlled by the length scale in which the magnetic field is modulated, introducing an effective size that favors adiabatic dynamics. The dependence of the residual energy on this length scale and the velocity at which the magnetic field sweeps out the chain is shown to be nonmonotonic. We determine the conditions for an optimal suppression of the residual energy of the final state and show that inhomogeneous driving can outperform conventional adiabatic schemes based on homogeneous control fields by several orders of magnitude. (paper)

  8. UTEX modeling of xenon signature sensitivity to geology and explosion cavity characteristics following an underground nuclear explosion

    Science.gov (United States)

    Lowrey, J. D.; Haas, D.

    2013-12-01

    Underground nuclear explosions (UNEs) produce anthropogenic isotopes that can potentially be used in the verification component of the Comprehensive Nuclear-Test-Ban Treaty. Several isotopes of radioactive xenon gas have been identified as radionuclides of interest within the International Monitoring System (IMS) and in an On-Site Inspection (OSI). Substantial research has been previously undertaken to characterize the geologic and atmospheric mechanisms that can drive the movement of radionuclide gas from a well-contained UNE, considering both sensitivities on gas arrival time and signature variability of xenon due to the nature of subsurface transport. This work further considers sensitivities of radioxenon gas arrival time and signatures to large variability in geologic stratification and generalized explosion cavity characteristics, as well as compares this influence to variability in the shallow surface.

  9. The adiabatic versus the diabatic approximation in the decoupling of electron and nuclear motion

    International Nuclear Information System (INIS)

    Every, A.G.

    1975-01-01

    There are two limiting approximations that are used as starting points for the analysis of a system of interacting electrons and nuclei. The more widely used is the adiabatic approximation in which one assumes that the electrons adjust adiabatically to the instantaneous configuration of the nuclei. This yields an effective internuclear potential. In treating the nuclear motion, this potential can legitimately be expanded to fourth order in nuclear displacements from equilibrium. The difficulties of extending this expansion further are discussed. In situations where two adiabatic potentials approach each other the so-called diabatic approximation has to be used. A novel application to non-radioactive processes in solids is discussed. (author)

  10. Seismic Methods of Identifying Explosions and Estimating Their Yield

    Science.gov (United States)

    Walter, W. R.; Ford, S. R.; Pasyanos, M.; Pyle, M. L.; Myers, S. C.; Mellors, R. J.; Pitarka, A.; Rodgers, A. J.; Hauk, T. F.

    2014-12-01

    Seismology plays a key national security role in detecting, locating, identifying and determining the yield of explosions from a variety of causes, including accidents, terrorist attacks and nuclear testing treaty violations (e.g. Koper et al., 2003, 1999; Walter et al. 1995). A collection of mainly empirical forensic techniques has been successfully developed over many years to obtain source information on explosions from their seismic signatures (e.g. Bowers and Selby, 2009). However a lesson from the three DPRK declared nuclear explosions since 2006, is that our historic collection of data may not be representative of future nuclear test signatures (e.g. Selby et al., 2012). To have confidence in identifying future explosions amongst the background of other seismic signals, and accurately estimate their yield, we need to put our empirical methods on a firmer physical footing. Goals of current research are to improve our physical understanding of the mechanisms of explosion generation of S- and surface-waves, and to advance our ability to numerically model and predict them. As part of that process we are re-examining regional seismic data from a variety of nuclear test sites including the DPRK and the former Nevada Test Site (now the Nevada National Security Site (NNSS)). Newer relative location and amplitude techniques can be employed to better quantify differences between explosions and used to understand those differences in term of depth, media and other properties. We are also making use of the Source Physics Experiments (SPE) at NNSS. The SPE chemical explosions are explicitly designed to improve our understanding of emplacement and source material effects on the generation of shear and surface waves (e.g. Snelson et al., 2013). Finally we are also exploring the value of combining seismic information with other technologies including acoustic and InSAR techniques to better understand the source characteristics. Our goal is to improve our explosion models

  11. Molecular wave function and effective adiabatic potentials calculated by extended multi-configuration time-dependent Hartree-Fock method

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Tsuyoshi; Ide, Yoshihiro; Yamanouchi, Kaoru [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo Bunkyo-ku, Tokyo, 113-0033 (Japan)

    2015-12-31

    We first calculate the ground-state molecular wave function of 1D model H{sub 2} molecule by solving the coupled equations of motion formulated in the extended multi-configuration time-dependent Hartree-Fock (MCTDHF) method by the imaginary time propagation. From the comparisons with the results obtained by the Born-Huang (BH) expansion method as well as with the exact wave function, we observe that the memory size required in the extended MCTDHF method is about two orders of magnitude smaller than in the BH expansion method to achieve the same accuracy for the total energy. Second, in order to provide a theoretical means to understand dynamical behavior of the wave function, we propose to define effective adiabatic potential functions and compare them with the conventional adiabatic electronic potentials, although the notion of the adiabatic potentials is not used in the extended MCTDHF approach. From the comparison, we conclude that by calculating the effective potentials we may be able to predict the energy differences among electronic states even for a time-dependent system, e.g., time-dependent excitation energies, which would be difficult to be estimated within the BH expansion approach.

  12. Asteroseismology of white dwarf stars. I - Adiabatic results

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, P.A.; Winget, D.E. (Texas, University (USA) McDonald Observatory, Austin (USA))

    1991-02-01

    A preliminary investigation of the asteroseismological properties of chemically stratified evolutionary DA and DB white dwarf models is reported. The period and kinetic energy distributions for nonradial g-modes of spherical harmonic indices l = 1-3 are computed in the adiabatic approximation, and the effects of varying the total stellar masss and the surface layer masses on the pulsation properties are studied using an extensive grid of models. Significant resonant mode trapping due to chemical stratification is found. Modes trapped in the outer layers have much lower kinetic energies; these minima also show up as minima in the period spacing between modes of consecutive radial overtone k. Mode trapping occurs at the same or nearly the same value of k for different l-values. Thus, l-values of trapped modes may be identified on the basis of their period ratios. It is shown that observational identification of these period ratios can be used to constrain the mass of the star and its surface layer. 68 refs.

  13. Stellar explosion

    International Nuclear Information System (INIS)

    Suraud, E.

    1987-01-01

    What is the energy source and which physical processes are powerful enough to generate this explosion which scatters the star. The knowledge progress of very dense matter allows the scenario reconstitution. An instability in the star core which is developing during milliseconds is the cause of this explosion [fr

  14. Adiabatic passage for a lossy two-level quantum system by a complex time method

    International Nuclear Information System (INIS)

    Dridi, G; Guérin, S

    2012-01-01

    Using a complex time method with the formalism of Stokes lines, we establish a generalization of the Davis–Dykhne–Pechukas formula which gives in the adiabatic limit the transition probability of a lossy two-state system driven by an external frequency-chirped pulse-shaped field. The conditions that allow this generalization are derived. We illustrate the result with the dissipative Allen–Eberly and Rosen–Zener models. (paper)

  15. Seismic waveform modeling of explosions at distances of 10-100 km

    International Nuclear Information System (INIS)

    Herrmann, R.B.; Al-Eqabi, G.; Hutchensen, K.

    1993-01-01

    The classification of shallow seismic sources in terms of size and mechanism is not trivial when the sources are small in size and recorded at distances less than 1000 km. Current operational techniques serve to distinguish between spatially distributed industrial chemical explosions with inter-shot delays and point sources on the basis on spectral scalloping. Data sets used for algorithm validation are not robust enough to contain both shallow ( 2 km) crustal earthquakes, large point chemical explosions, as well as arealy distributed chemical explosions. Wave propagation theory may make up for these knowledge gaps. Perfect event discrimination is not presently possible. The suite of all recorded seismic events can be, and is being, culled on the basis of depth, spectral characteristics indicative of delayed shots and spectral ratios between different phases in different frequency bands, leaving a subset of events requiring further examination, if possible

  16. Evolution of f{sub NL} to the adiabatic limit

    Energy Technology Data Exchange (ETDEWEB)

    Elliston, Joseph; Mulryne, David J.; Tavakol, Reza [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Seery, David, E-mail: J.Elliston@qmul.ac.uk, E-mail: D.Mulryne@qmul.ac.uk, E-mail: D.Seery@sussex.ac.uk, E-mail: R.Tavakol@qmul.ac.uk [Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom)

    2011-11-01

    We study inflationary perturbations in multiple-field models, for which ζ typically evolves until all isocurvature modes decay — the {sup a}diabatic limit{sup .} We use numerical methods to explore the sensitivity of the local-shape bispectrum to the process by which this limit is achieved, finding an appreciable dependence on model-specific data such as the time at which slow-roll breaks down or the timescale of reheating. In models with a sum-separable potential where the isocurvature modes decay before the end of the slow-roll phase we give an analytic criterion for the asymptotic value of f{sub NL} to be large. Other examples can be constructed using a waterfall field to terminate inflation while f{sub NL} is transiently large, caused by descent from a ridge or convergence into a valley. We show that these two types of evolution are distinguished by the sign of the bispectrum, and give approximate expressions for the peak f{sub NL}.

  17. The explosion-proof container, satisfying the IAEA norms on safety

    International Nuclear Information System (INIS)

    Syrunin, M.A.; Fedorenko, A.G.; Ivanov, A.G.; Abakumov, A.I.; Nizovtsev, P.N.; Loginov, P.G.; Smolyakov, A.A.; Solov'ev, V.P.

    1998-01-01

    Safety of radioactive materials (RM) transportation is under strict control of the international norms of IAEA, aimed to ensure non-proliferation of hazardous materials in the environments. At the same time the nuclear countries use much more dangerous transportations of two types of hazardous materials. Probability of emergency explosion of high explosives (HE) during transportation and storage of such constructions is not equal to zero. HE explosion can be caused by: 1)excess of mechanical effects, allowable by the norms, on an explosive 2)lightening or fire 3)terrorist attack 4)radio controlled or time controlled mechanism in case of the terrorist device. It is obvious that an accident with explosion HE element of the nuclear weapon in an usual container, which meets the IAEA norms, but is not explosion-proof, will result in its destruction, RM dispersal, and inadmissible pollution of the environments. Therefore, it is urgent need for development of the container, which is able to withstand explosion of HE, placed in it, and to confine released RM inside of it. The experimental prototype of the load-bearing shell of the explosion-proof container (EC) can be the successfully tested spherical steel - glass plastic shell, having high-strength throats and lids. Having weight of 45-50 kg it is able to withstand internal explosion with energy more than 1.4 kg of the TNT equivalent. To preserve the explosion-proofness property in the abnormal environments during transportation, the explosion-proof container should be placed in the protective supporting transport device or the transport container (TC), consisting of the external thin-walled steel shell and the damping heat-proof layer from heat-resistant foam plastic. To justify the design parameters of such container, the tests for development and revision of the numerical model parameters were carried out. With use of this model the calculations were performed to calculate loads and the container response to 1

  18. Saline Cavern Adiabatic Compressed Air Energy Storage Using Sand as Heat Storage Material

    Directory of Open Access Journals (Sweden)

    Martin Haemmerle

    2017-03-01

    Full Text Available Adiabatic compressed air energy storage systems offer large energy storage capacities and power outputs beyond 100MWel. Salt production in Austria produces large caverns which are able to hold pressure up to 100 bar, thus providing low cost pressurized air storage reservoirs for adiabatic compressed air energy storage plants. In this paper the results of a feasibility study is presented, which was financed by the Austrian Research Promotion Agency, with the objective to determine the adiabatic compressed air energy storage potential of Austria’s salt caverns. The study contains designs of realisable plants with capacities between 10 and 50 MWel, applying a high temperature energy storage system currently developed at the Institute for Energy Systems and Thermodynamics in Vienna. It could be shown that the overall storage potential of Austria’s salt caverns exceeds a total of 4GWhel in the year 2030 and, assuming an adequate performance of the heat exchanger, that a 10MWel adiabatic compressed air energy storage plant in Upper Austria is currently feasible using state of the art thermal turbomachinery which is able to provide a compressor discharge temperature of 400 °C.

  19. Risk assessment and consequence modeling of BLEVE explosion wave phenomenon of LPG spherical tank in a refinery

    Directory of Open Access Journals (Sweden)

    Mohammad Kamaei

    2016-06-01

    Full Text Available Introduction: Although human industrial activities are as a part of efforts to achieve greater prosperity, the risks related to these activities are also expanding. Hazard identification and risk assessment in the oil and gas industries are essential to reduce the frequency and severity of accidents and minimize damage to people and property before their occurrence. The aim of this study was to evaluate the liquefied and pressurized petroleum gas spherical tanks in a refinery and assessing the risks of Boiling Liquid Expanding Vapor Explosion (BLEVE phenomenon. Material and Method: In this study, the risks of BLEVE phenomenon were assessed, using the Bowtie method. The consequences of explosion wave phenomenon and the resulting wave quantity and its impacts on the neighboring machineries and equipment were analyzed. PHAST software version 6.54 has been used for modeling the BLEVE phenomenon. Result: In this evaluation, generally five causes and two consequences were identified for BLEVE phenomenon. In order to reduce its consequences, forty-three controlling measures were introduced to prevent the BLEVE phenomenon and the impacts of 31 control measures were identified. According to the conducted analysis, it was found that the spherical tank blast wave caused by LPG can lead to explosion of close located tanks which can create a chain of explosions. Conclusion: The results of modeling and risk assessment can be used to identify the BLEVE phenomenon causes and its effects on nearby people and equipment. Based on these results, preventive controlling measures can be implemented and also be determined by adopting proper design and layout, margin of safety for personnel, equipment and accessories.

  20. Explosions in Landau Vlasov dynamics

    International Nuclear Information System (INIS)

    Suraud, E.; Cussol, D.; Gregoire, C.; Boilley, D.; Pi, M.; Schuck, P.; Remaud, B.; Sebille, F.

    1988-01-01

    A microscopic study of the quasi-fusion/explosion transition is presented in the framework of Landau-Vlasov simulations of intermediate energy heavy-ion collisions (bombarding energies between 10 and 100 MeV/A). A detailed analysis in terms of the Equation of State of the system is performed. In agreement with schematic models we find that the composite nuclear system formed in the collision does explode when it stays long enough in the mechanically unstable region (spinodal region). Quantitative estimates of the explosion threshold are given for central symmetric reactions (Ca+Ca and Ar+Ti). The effect of the nuclear matter compressibility modulus is discussed

  1. Numerical Simulation of Explosive Forming Using Detonating Fuse

    Directory of Open Access Journals (Sweden)

    H Iyama

    2017-09-01

    Full Text Available The explosive forming is a characteristic method. An underwater shock wave is generated by underwater explosion of an explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming shape is depend on the shock pressure distribution act on the metal plate. This pressure distribution is able to change by the shape of explosive, a mass of explosive and a shape of pressure vessel. On the other hand, we need the pressure vessel for food processing by the underwater shock wave. Therefore, we propose making the pressure vessel by this explosive forming. One design suggestion of pressure vessel made of stainless steel was considered. However, we cannot decide suitable conditions, the mass of the explosive and the distance between the explosive and the metal plate to make the pressure vessel. In order to decide these conditions, we have tried the numerical simulation on this explosive forming. The basic simulation method was ALE (Arbitrary Laglangian Eulerian method including with Mie-Grümeisen EOS (equation of state, JWL EOS, Johnson-Cook constitutive equation for a material model. In this paper, the underwater pressure contours to clear the propagations of the underwater shock wave, forming processes and deformation velocity of the metal plate is shown and it will be discussed about those results.

  2. Adiabatic Gasification and Pyrolysis of Coffee Husk Using Air-Steam for Partial Oxidation

    OpenAIRE

    Catalina Rodriguez; Gerardo Gordillo

    2011-01-01

    Colombian coffee industry produces about 0.6 million tons of husk (CH) per year which could serve as feedstock for thermal gasification to produce gaseous and liquid fuels. The current paper deals with: (i) CH adiabatic gasification modeling using air-steam blends for partial oxidation and (ii) experimental thermogravimetric analysis to determine the CH activation energy (E). The Chemical Equilibrium with Applications Program (CEA), developed by NASA, was used to estimate the effect of equiva...

  3. Fire and explosion hazards to flora and fauna from explosives.

    Science.gov (United States)

    Merrifield, R

    2000-06-30

    Deliberate or accidental initiation of explosives can produce a range of potentially damaging fire and explosion effects. Quantification of the consequences of such effects upon the surroundings, particularly on people and structures, has always been of paramount importance. Information on the effects on flora and fauna, however, is limited, with probably the weakest area lying with fragmentation of buildings and their effects on different small mammals. Information has been used here to gain an appreciation of the likely magnitude of the potential fire and explosion effects on flora and fauna. This is based on a number of broad assumptions and a variety of data sources including World War II bomb damage, experiments performed with animals 30-40 years ago, and more recent field trials on building break-up under explosive loading.

  4. Connection between adiabaticity and the mirror mode

    International Nuclear Information System (INIS)

    Cohen, R.H.

    1976-01-01

    The size of magnetic moment jumps of a particle in a long, thin equilibrium magnetic mirror field is shown to be related to the complex zeroes of the mirror mode parameter B + 4πdP/sub perpendicular//dB. A consequence is that adiabaticity places a lower limit on β than does the mirror mode

  5. Polaronic and bipolaronic structures in the adiabatic Hubbard-Holstein model involving 2 electrons and its extensions

    International Nuclear Information System (INIS)

    Proville, L.

    1998-01-01

    This thesis brings its contribution to the bipolaronic theory which might explain the origin of superconductivity at high temperature. A polaron is a quasiparticle made up of a localized electron and a deformation in the crystal structure. 2 electrons in singlet states localized on the same site form a bipolaron. Whenever the Coulomb repulsion between the 2 electrons is too strong bipolaron turns into 2 no bound polarons. We study the existence and the mobility of bipolarons. We describe the electron-phonon interaction by the Holstein term and the Coulomb repulsion by the Hubbard term. 2 assumptions are made: - the local electron-phonon interaction is strong and opposes the Coulomb repulsion between Hubbard type electrons - the system is close to the adiabatic limit. The system is reduced to 2 electrons in order to allow an exact treatment and the investigation of some bipolaronic bound states. At 2-dimensions the existence of bipolarons requires a very strong coupling which forbids any classical mobility. In some cases an important tunneling effect appears and we show that mobile bipolarons exist in a particular parameter range. Near the adiabatic limit we prove that polaronic and bipolaronic structures exist for a great number of electrons. (A.C.)

  6. Optical detection of explosives: spectral signatures for the explosive bouquet

    Science.gov (United States)

    Osborn, Tabetha; Kaimal, Sindhu; Causey, Jason; Burns, William; Reeve, Scott

    2009-05-01

    Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint regions. Here we will describe some of these high resolution measurements and discuss strategies for selecting useful spectral signature regions for individual molecular markers of interest.

  7. Pre-History Of The Concepts Underlying Stimulated Raman Adiabatic Passage (STIRAP)

    International Nuclear Information System (INIS)

    Shore, B.W.

    2013-01-01

    This tutorial review discusses some of the work that preceded development, twenty-five years ago, of the stimulated Raman adiabatic passage (STIRAP) technique, now widely used in the controlled coherent dynamics of three-state systems, noting how the use of time-dependent adiabatically-evolving population-trapping dark states made possible the robust and highly-efficient population transfer between quantum states that first popularized STIRAP. Preceding the history discussion is a tutorial definition of STIRAP and its necessary and sufficient ingredients — understanding that has led to applications well beyond those of the original quantum systems. This review also discusses the relationship between STIRAP and two related procedures: chirped Raman adiabatic passage (RCAP or CHIRAP) and electromagnetically induced transparency (EIT) with slow and captured light. It concludes with a brief discussion of ways in which contemporary STIRAP has extended the original concept and enlarged the definition, beyond that of simple quantum systems to classical macroscopic devices. Appendices offer further details. The presentation emphasizes theory but with illustrations of experimental results. (author)

  8. Adiabatic pair creation in heavy-ion and laser fields

    International Nuclear Information System (INIS)

    Pickl, P.; Durr, D.

    2008-01-01

    The planned generation of lasers and heavy-ion colliders renews the hope to see electron-positron pair creation in strong classical fields. This old prediction is usually referred to as spontaneous pair creation. We observe that both heavy-ion collisions and pair creation in strong laser fields, are instances of the theory of adiabatic pair creation. We shall present the theory, thereby correcting earlier results. We give the momentum distribution of created pairs in overcritical fields. We discuss carefully the proposed experimental verifications and conclude that pure laser-based experiments are highly questionable. We propose a new experiment, joining laser fields and heavy ions, which may be feasible with present-day technology and which may indeed verify the theoretical prediction of adiabatic pair creation. Our presentation relies on recent rigorous works in mathematical physics. (authors)

  9. The control and prevention of dust explosions

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    Papers presented discussed: explosion characteristics and hybrid mixtures explosion characteristics and influencing factors, propagation of dust explosions in ducts, prevention of dust explosions, desensitization, explosion-proof type of construction, explosion pressure relief, optical flame barriers, slide-valves for explosion protection, Ventex explosion barrier valves, grinding and mixing plants, spray driers, dust explosions in silos, and explosion-proof bucket elevators. One paper has been abstracted separately.

  10. Adiabatic approximation in the ultrastrong-coupling regime of an oscillator and two qubits

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ping; Zou, Ping [Laboratory of Nanophotonic Functional Materials and Devices, SIPSE and LQIT, South China Normal University, Guangzhou 510006 (China); Zhang, Zhi-Ming, E-mail: zmzhang@scnu.edu.cn [Laboratory of Nanophotonic Functional Materials and Devices, SIPSE and LQIT, South China Normal University, Guangzhou 510006 (China)

    2012-10-01

    We present a system composed of two flux qubits and a transmission-line resonator. Instead of using the rotating wave approximation (RWA), we analyze the system by the adiabatic approximation methods under two opposite extreme conditions. Basic properties of the system are calculated and compared under these two different conditions. Relative energy-level spectrum of the system in the adiabatic displaced oscillator basis is shown, and the theoretical result is compared with the numerical solution. -- Highlights: ► Our work shows that the adiabatic approximations may work also in the ultrastrong coupling limit. ► Both of the approximation methods are valid in a large range of coupling strength, including the ultrastrong coupling regime. ► The results of the approximate formula meet well the exact numerical solution.

  11. On the adiabatic walking of plasma waves in a pulsar magnetosphere

    International Nuclear Information System (INIS)

    Melikidze, George I.; Gil, Janusz; Mitra, Dipanjan

    2014-01-01

    The pulsar radio emission is generated in the near magnetosphere of the neutron star, and it must propagate through the rest of it to emerge into the interstellar medium. An important issue is whether this propagation affects the planes of polarization of the generated radiation. Observationally, there is sufficient evidence that the emerging radiation is polarized parallel or perpendicular to the magnetic field line planes that should be associated with the ordinary (O) and extraordinary (X) plasma modes, respectively, excited by some radiative process. This strongly suggests that the excited X and O modes are not affected by the so-called adiabatic walking that causes a slow rotation of polarization vectors. In this paper, we demonstrate that the conditions for adiabatic walking are not fulfilled within the soliton model of pulsar radio emission, in which the coherent curvature radiation occurs at frequencies much lower than the characteristic plasma frequency, The X mode propagates freely and observationally represents the primary polarization mode. The O mode has difficulty escaping from the pulsar plasma; however, it is sporadically observed as a weaker secondary polarization mode. We discuss a possible scenario under which the O mode can also escape from the plasma and reach an observer.

  12. Effects of explosion-generated shock waves in ducts

    International Nuclear Information System (INIS)

    Busby, M.R.; Kahn, J.E.; Belk, J.P.

    1976-01-01

    An explosion in a space causes an increase in temperature and pressure. To quantify the challenge that will be presented to essential components in a ventilation system, it is necessary to analyze the dynamics of a shock wave generated by an explosion, with attention directed to the propagation of such a wave in a duct. Using the equations of unsteady flow and shock tube theory, a theoretical model has been formulated to provide flow properties behind moving shock waves that have interacted with various changes in duct geometry. Empirical equations have been derived to calculate air pressure, temperature, Mach number, and velocity in a duct following an explosion

  13. Adiabaticity and gravity theory independent conservation laws for cosmological perturbations

    Science.gov (United States)

    Romano, Antonio Enea; Mooij, Sander; Sasaki, Misao

    2016-04-01

    We carefully study the implications of adiabaticity for the behavior of cosmological perturbations. There are essentially three similar but different definitions of non-adiabaticity: one is appropriate for a thermodynamic fluid δPnad, another is for a general matter field δPc,nad, and the last one is valid only on superhorizon scales. The first two definitions coincide if cs2 = cw2 where cs is the propagation speed of the perturbation, while cw2 = P ˙ / ρ ˙ . Assuming the adiabaticity in the general sense, δPc,nad = 0, we derive a relation between the lapse function in the comoving slicing Ac and δPnad valid for arbitrary matter field in any theory of gravity, by using only momentum conservation. The relation implies that as long as cs ≠cw, the uniform density, comoving and the proper-time slicings coincide approximately for any gravity theory and for any matter field if δPnad = 0 approximately. In the case of general relativity this gives the equivalence between the comoving curvature perturbation Rc and the uniform density curvature perturbation ζ on superhorizon scales, and their conservation. This is realized on superhorizon scales in standard slow-roll inflation. We then consider an example in which cw =cs, where δPnad = δPc,nad = 0 exactly, but the equivalence between Rc and ζ no longer holds. Namely we consider the so-called ultra slow-roll inflation. In this case both Rc and ζ are not conserved. In particular, as for ζ, we find that it is crucial to take into account the next-to-leading order term in ζ's spatial gradient expansion to show its non-conservation, even on superhorizon scales. This is an example of the fact that adiabaticity (in the thermodynamic sense) is not always enough to ensure the conservation of Rc or ζ.

  14. Asymmetric Explosion of Type Ia Supernovae and Their Observational Signatures

    International Nuclear Information System (INIS)

    Maeda, Keiichi

    2010-01-01

    The nature of Type Ia supernova (SN Ia) explosions has not yet been clarified, despite their importance in astrophysics and cosmology. Recent theoretical investigations suggest that asymmetric distribution of initial thermonuclear sparks may be a key in the SN Ia explosion mechanism. In this paper, the first observational evidence of the asymmetry in SN Ia explosions is presented: We have found that late-time nebular spectra of various SNe Ia show a diversity in wavelengths of emission lines. This feature is inconsistent with any spherically symmetric explosion models, and indicates that the innermost region, a likely product of the deflagration wave propagation, shows an off-set with respect to the explosion center. The diversity in the emission-line wavelengths could naturally be explained by a combination of different viewing angles.

  15. Experimental demonstration of efficient and robust second harmonic generation using the adiabatic temperature gradient method

    Science.gov (United States)

    Dimova, E.; Steflekova, V.; Karatodorov, S.; Kyoseva, E.

    2018-03-01

    We propose a way of achieving efficient and robust second-harmonic generation. The technique proposed is similar to the adiabatic population transfer in a two-state quantum system with crossing energies. If the phase mismatching changes slowly, e.g., due to a temperature gradient along the crystal, and makes the phase match for second-harmonic generation to occur, then the energy would be converted adiabatically to the second harmonic. As an adiabatic technique, the second-harmonic generation scheme presented is stable to variations in the crystal parameters, as well as in the input light, crystal length, input intensity, wavelength and angle of incidence.

  16. Low-energy P-wave phaseshifts for positron-hydrogen elastic scattering using an adiabatic approximation

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Beker, C.A.; Farina, J.E.G.

    1981-01-01

    P-wave phaseshifts for positron-hydrogen elastic scattering are calculated using a new adiabatic approximation in which the length of the radius vector from the proton to the positron is fixed but its direction is allowed to vary. This adiabatic approximation makes possible the full inclusion in the calculation of virtual states in which angular momentum is transferred to the target H atom. The results obtained agree qualitatively with the highly accurate results of Bhatia and co-workers (Phys. Rev.; A9:219 (1974)) and are much closer to them than the results obtained using the usual adiabatic approximation in which the radius vector from the proton to the positron is fixed. (author)

  17. Adiabatic compression and radiative compression of magnetic fields

    International Nuclear Information System (INIS)

    Woods, C.H.

    1980-01-01

    Flux is conserved during mechanical compression of magnetic fields for both nonrelativistic and relativistic compressors. However, the relativistic compressor generates radiation, which can carry up to twice the energy content of the magnetic field compressed adiabatically. The radiation may be either confined or allowed to escape

  18. Deflagration explosion of an unconfined fuel vapor cloud

    International Nuclear Information System (INIS)

    Taki, S.; Ogawa, Y.

    1981-01-01

    In the reported study, explosions are produced by injecting a small amount of liquefied petroleum gas (LPG) into air. The ignition and subsequent evolution of the explosion of the unconfined vapor cloud are observed by the simultaneous use of direct photographs and pressure recording. The intensity of the compression waves generated by unconfined combustion are modeled on the basis of the solution of the conservation equations for the flow associated with a spherically symmetric expanding piston. The obtained results are compared with the measurements. It is pointed out that the development of unconfined fuel vapor cloud explosions can be divided into two stages, including a deflagration propagating in premixed gases, which is followed by a diffusion flame promoted by buoyancy and convection. The experimental result from the pressure measurement is found to be quantitatively consistent with the result obtained from the spherical piston model

  19. Chernobyl explosion bombshell

    International Nuclear Information System (INIS)

    Martin, S.; Arnott, D.

    1988-01-01

    It is suggested that the explosion at the Chernobyl-4 reactor in April 1986 was a nuclear explosion. The evidence for this is examined. The sequence of events at Chernobyl is looked at to see if the effects were like those from a nuclear explosion. The question of whether a United Kingdom reactor could go prompt critical is discussed. It is concluded that prompt criticality excursions are possible, but the specific Chernobyl sequence is impossible. (UK)

  20. Multi-scale fracture damage associated with underground chemical explosions

    Science.gov (United States)

    Swanson, E. M.; Sussman, A. J.; Wilson, J. E.; Townsend, M. J.; Prothro, L. B.; Gang, H. E.

    2018-05-01

    Understanding rock damage induced by explosions is critical for a number of applications including the monitoring and verification of underground nuclear explosions, mine safety issues, and modeling fluid flow through fractured rock. We use core observations, televiewer logs, and thin section observations to investigate fracture damage associated with two successive underground chemical explosions (SPE2 and SPE3) in granitic rock at both the mesoscale and microscale. We compare the frequency and orientations of core-scale fractures, and the frequency of microfractures, between a pre-experiment core and three post-experiment cores. Natural fault zones and explosion-induced fractures in the vicinity of the explosive source are readily apparent in recovered core and in thin sections. Damage from faults and explosions is not always apparent in fracture frequency plots from televiewer logs, although orientation data from these logs suggests explosion-induced fracturing may not align with the pre-existing fracture sets. Core-scale observations indicate the extent of explosion-induced damage is 10.0 m after SPE2 and 6.8 m after SPE3, despite both a similar size and location for both explosions. At the microscale, damage is observed to a range distance of 10.2 ± 0.9 m after SPE2, and 16.6 ± 0.9 and 11.2 ± 0.6 in two different cores collected after SPE3. Additional explosion-induced damage, interpreted to be the result of spalling, is readily apparent near the surface, but only in the microfracture data. This depth extent and intensity of damage in the near-surface region also increased after an additional explosion. This study highlights the importance of evaluating structural damage at multiple scales for a more complete characterization of the damage, and particularly shows the importance of microscale observations for identifying spallation-induced damage.

  1. The numerical study the rising of the explosion clouds in the uniform atmosphere

    International Nuclear Information System (INIS)

    Li Xiaoli; Zheng Yi; Chao Ying

    2010-01-01

    This paper is to study the rising of the explosion clouds in the uniform atmosphere, the numerical model is based on the assumption that effects the clouds are gravity and buoyancy. The model is testified by Rayleigh-Taylor unsteady problem. The evolution of the density and the velocity during the rising of the explosion clouds are provided, and the computational results are reasonable compared to the rising of the real nuclear explosion cloud. (authors)

  2. Adiabatic partial Siberian snake turn-on with no beam depolarization

    International Nuclear Information System (INIS)

    Phelps, R.A.; Anferov, V.A.; Chu, C.M.; Courant, E.D.; Crandell, D.A.; Derbenev, Y.S.; Kaufman, W.A.; Koulsha, A.V.; Krisch, A.D.; Nurushev, T.S.; Raczkowksi, D.B.; Sund, S.E.; Wong, V.K.; Caussyn, D.D.; Ellison, T.J.P.; Lee, S.Y.; Sperisen, F.; Stephenson, E.J.; von Przewoski, B.; Baiod, R.; Khiari, F.Z.; Ratner, L.G.; Sato, H.

    1994-01-01

    A recent experiment in the IUCF cooler ring studied the adiabatic turn-on of a partial Siberian snake at 370 MeV, where the spin tune, ν s is 21/2 for all snake strengths. The snake consisted of two rampable warm solenoid magnets in series with a superconducting solenoid; this combination allowed varying the snake strength between about 0 and 25% at 370 MeV. We measured the beam polaraization after varying the snake either 1, 2, or 10 times; we found with good precision that no polarization was lost. This supports the conjecture that a Siberian snake can be ramped adiabatically at an energy where the spin tune is a half integer

  3. Recall Performance for Content-Addressable Memory Using Adiabatic Quantum Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Imam, Neena [ORNL; Humble, Travis S. [ORNL; McCaskey, Alex [ORNL; Schrock, Jonathan [ORNL; Hamilton, Kathleen E. [ORNL

    2017-09-01

    A content-addressable memory (CAM) stores key-value associations such that the key is recalled by providing its associated value. While CAM recall is traditionally performed using recurrent neural network models, we show how to solve this problem using adiabatic quantum optimization. Our approach maps the recurrent neural network to a commercially available quantum processing unit by taking advantage of the common underlying Ising spin model. We then assess the accuracy of the quantum processor to store key-value associations by quantifying recall performance against an ensemble of problem sets. We observe that different learning rules from the neural network community influence recall accuracy but performance appears to be limited by potential noise in the processor. The strong connection established between quantum processors and neural network problems supports the growing intersection of these two ideas.

  4. Adiabat_1ph 3.0 and the MAGMA website: educational and research tools for studying the petrology and geochemistry of plate margins

    Science.gov (United States)

    Antoshechkina, P. M.; Asimow, P. D.

    2010-12-01

    Adiabat_1ph is a menu-driven front-end to the MELTS, pMELTS and pHMELTS models of thermodynamic equilibrium in silicate systems. Its public release in late 2004 was described in a software brief in G3 (doi:10.1029/2004GC000816). The software package is available for Windows, MacOS X, and Linux and includes Perl scripts that, if desired, will allow almost complete automation of the calculation process. Adiabat_1ph 3.0 is scheduled for release in October 2010 and includes, for the first time, an option to double-click the run_adiabat.command script and to drag and drop file names from a browser (e.g. Explorer on Windows, Finder on Mac). This alternative mode of operation is particularly suited for teaching at undergraduate and graduate levels, as well as for quick, ad hoc, calculations for research purposes. The original method of invoking the program from the command line is retained for more intensive applications. Version 3.0 is the first to specifically target the Windows 7 and Snow Leopard platforms. The release also includes new features that are relevant to the study of plate margins. The Marianas Trough forms the southern part of the Izu-Bonin-Marianas (IBM) arc system, one of the chosen areas of focus for the MARGINS Subduction Factory initiative. Attempts to model the complicated hydrous fractionation trends observed in this region were the motivation for adding modified versions of the ‘reverse-fractionation’ and ‘amoeba’ routines (see doi:10.1016/S0012-821X(04)00058-5) into adiabat_1ph. The ‘amoeba’ scheme, which varies a trial parental melt composition until forward fractionation yields a specified target composition, has been extended so the best-fit liquid line of descent of a group of samples can be found. We have tested the adiabat_1ph versions using glass compositions from the 9N area of the East Pacific Rise and melt inclusions from the Siqueiros Fracture Zone (see Antoshechkina et al., this meeting). One of the first user requested

  5. A study on vapor explosions

    International Nuclear Information System (INIS)

    Takagi, N.; Shoji, M.

    1979-01-01

    An experimental study was carried out for vapor explosions of molten tin falling in water. For various initial metal temperatures and subcooling of water, transient pressure of the explosions, relative frequency of the explosions and the position where the explosions occur were measured in detail. The influence of ambient pressure was also investigated. From the results, it was concluded that the vapor explosion is closely related to the collapse of a vapor film around the molten metal. (author)

  6. Recent Advances in Understanding Large Scale Vapour Explosions

    International Nuclear Information System (INIS)

    Board, S.J.; Hall, R.W.

    1976-01-01

    In foundries, violent explosions occur occasionally when molten metal comes into contact with water. If similar explosions can occur with other materials, hazardous situations may arise for example in LNG marine transportation accidents, or in liquid cooled reactor incidents when molten UO 2 contacts water or sodium coolant. Over the last 10 years a large body of experimental data has been obtained on the behaviour of small quantities of hot material in contact with a vaporisable coolant. Such experiments generally give low energy yields, despite producing fine fragmentation of the molten material. These events have been interpreted in terms of a wide range of phenomena such as violent boiling, liquid entrainment, bubble collapse, superheat, surface cracking and many others. Many of these studies have been aimed at understanding the small scale behaviour of the particular materials of interest. However, understanding the nature of the energetic events which were the original cause for concern may also be necessary to give confidence that violent events cannot occur for these materials in large scale situations. More recently, there has been a trend towards larger experiments and some of these have produced explosions of moderately high efficiency. Although occurrence of such large scale explosions can depend rather critically on initial conditions in a way which is not fully understood, there are signs that the interpretation of these events may be more straightforward than that of the single drop experiments. In the last two years several theoretical models for large scale explosions have appeared which attempt a self contained explanation of at least some stages of such high yield events: these have as their common feature a description of how a propagating breakdown of an initially quasi-stable distribution of materials is induced by the pressure and flow field caused by the energy release in adjacent regions. These models have led to the idea that for a full

  7. Low-Power Adiabatic Computing with Improved Quasistatic Energy Recovery Logic

    Directory of Open Access Journals (Sweden)

    Shipra Upadhyay

    2013-01-01

    Full Text Available Efficiency of adiabatic logic circuits is determined by the adiabatic and non-adiabatic losses incurred by them during the charging and recovery operations. The lesser will be these losses circuit will be more energy efficient. In this paper, a new approach is presented for minimizing power consumption in quasistatic energy recovery logic (QSERL circuit which involves optimization by removing the nonadiabatic losses completely by replacing the diodes with MOSFETs whose gates are controlled by power clocks. Proposed circuit inherits the advantages of quasistatic ERL (QSERL family but is with improved power efficiency and driving ability. In order to demonstrate workability of the newly developed circuit, a 4 × 4 bit array multiplier circuit has been designed. A mathematical expression to calculate energy dissipation in proposed inverter is developed. Performance of the proposed logic (improved quasistatic energy recovery logic (IQSERL is analyzed and compared with CMOS and reported QSERL in their representative inverters and multipliers in VIRTUOSO SPECTRE simulator of Cadence in 0.18 μm UMC technology. In our proposed (IQSERL inverter the power efficiency has been improved to almost 20% up to 50 MHz and 300 fF external load capacitance in comparison to CMOS and QSERL circuits.

  8. Hydroxylamine nitrate self-catalytic kinetics study with adiabatic calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lijun [Mary Kay O' Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University System, College Station, TX 77843-3122 (United States); Wei Chunyang [BASF Corporation, Wyandotte, MI 48192 (United States); Guo Yuyan; Rogers, William J. [Mary Kay O' Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University System, College Station, TX 77843-3122 (United States); Sam Mannan, M. [Mary Kay O' Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A and M University System, College Station, TX 77843-3122 (United States)], E-mail: mannan@tamu.edu

    2009-03-15

    Hydroxylamine nitrate (HAN) is an important member of the hydroxylamine compound family with applications that include equipment decontamination in the nuclear industry and aqueous or solid propellants. Due to its instability and autocatalytic behavior, HAN has been involved in several incidents at the Hanford and Savannah River Site (SRS) [Technical Report on Hydroxylamine Nitrate, US Department of Energy, 1998]. Much research has been conducted on HAN in different areas, such as combustion mechanism, decomposition mechanism, and runaway behavior. However, the autocatalytic decomposition behavior of HAN at runaway stage has not been fully addressed due to its highly exothermic and rapid decomposition behavior. This work is focused on extracting HAN autocatalytic kinetics and analyzing HAN critical behavior from adiabatic calorimetry measurements. A lumped autocatalytic kinetic model for HAN and associated model parameters are determined. Also the storage and handling critical conditions of diluted HAN solution without metal presence are quantified.

  9. Hydroxylamine nitrate self-catalytic kinetics study with adiabatic calorimetry

    International Nuclear Information System (INIS)

    Liu Lijun; Wei Chunyang; Guo Yuyan; Rogers, William J.; Sam Mannan, M.

    2009-01-01

    Hydroxylamine nitrate (HAN) is an important member of the hydroxylamine compound family with applications that include equipment decontamination in the nuclear industry and aqueous or solid propellants. Due to its instability and autocatalytic behavior, HAN has been involved in several incidents at the Hanford and Savannah River Site (SRS) [Technical Report on Hydroxylamine Nitrate, US Department of Energy, 1998]. Much research has been conducted on HAN in different areas, such as combustion mechanism, decomposition mechanism, and runaway behavior. However, the autocatalytic decomposition behavior of HAN at runaway stage has not been fully addressed due to its highly exothermic and rapid decomposition behavior. This work is focused on extracting HAN autocatalytic kinetics and analyzing HAN critical behavior from adiabatic calorimetry measurements. A lumped autocatalytic kinetic model for HAN and associated model parameters are determined. Also the storage and handling critical conditions of diluted HAN solution without metal presence are quantified

  10. Aspects regarding explosion risk assessment

    Directory of Open Access Journals (Sweden)

    Părăian Mihaela

    2017-01-01

    Full Text Available Explosive risk occurs in all activities involving flammable substances in the form of gases, vapors, mists or dusts which, in mixture with air, can generate an explosive atmosphere. As explosions can cause human losses and huge material damage, the assessment of the explosion risk and the establishment of appropriate measures to reduce it to acceptable levels according to the standards and standards in force is of particular importance for the safety and health of people and goods.There is no yet a recognized method of assessing the explosion risk, but regardless of the applied method, the likelihood of an explosive atmosphere occurrence has to be determined, together with the occurrence of an efficient ignition source and the magnitude of foreseeable consequences. In assessment processes, consequences analysis has a secondary importance since it’s likely that explosions would always involve considerable damage, starting from important material damages and up to human damages that could lead to death.The purpose of the work is to highlight the important principles and elements to be taken into account for a specific risk assessment. An essential element in assessing the risk of explosion in workplaces where explosive atmospheres may occur is technical installations and personal protective equipment (PPE that must be designed, manufactured, installed and maintained so that they cannot generate a source of ignition. Explosion prevention and protection requirements are governed by specific norms and standards, and a main part of the explosion risk assessment is related to the assessment of the compliance of the equipment / installation with these requirements.

  11. Experimental evaluation of ammonia adiabatic absorption into ammonia–lithium nitrate solution using a fog jet nozzle

    International Nuclear Information System (INIS)

    Zacarías, Alejandro; Venegas, María; Lecuona, Antonio; Ventas, Rubén

    2013-01-01

    This paper presents the experimental assessment of the adiabatic absorption of ammonia vapour into an ammonia–lithium nitrate solution using a fog jet nozzle. The ammonia mass fraction was kept constant at 46.08% and the absorber pressure was varied in the range 355–411 kPa. The nozzle was located at the top of the absorption chamber, at a height of 205 mm measured from the bottom surface. The diluted solution flow rate was modified between 0.04 and 0.08 kg s −1 and the solution inlet temperature in the range 25.9–30.2 °C. The influence of these variables on the approach to adiabatic equilibrium factor, outlet subcooling, absorption ratio and mass transfer coefficient is analysed. The approach to adiabatic equilibrium factor for the conditions essayed is always between 0.82 and 0.93. Pressure drop of the solution entering the absorption chamber is also evaluated. Correlations for the approach to adiabatic equilibrium factor and the Sherwood number are given. - Highlights: ► Adiabatic absorption of NH 3 vapour into NH 3 –LiNO 3 using fog jet nozzle created spray. ► Pressure drop of the solution entering to the absorption chamber is evaluated. ► Approach to adiabatic equilibrium factor (F) is between 0.82 and 0.93 at 205 mm height. ► Experimental values of mass transfer coefficient and outlet subcooling are presented. ► Correlations for F and Sherwood number are given.

  12. Quantum gas in the fast forward scheme of adiabatically expanding cavities: Force and equation of state

    Science.gov (United States)

    Babajanova, Gulmira; Matrasulov, Jasur; Nakamura, Katsuhiro

    2018-04-01

    With use of the scheme of fast forward which realizes quasistatic or adiabatic dynamics in shortened timescale, we investigate a thermally isolated ideal quantum gas confined in a rapidly dilating one-dimensional (1D) cavity with the time-dependent size L =L (t ) . In the fast-forward variants of equation of states, i.e., Bernoulli's formula and Poisson's adiabatic equation, the force or 1D analog of pressure can be expressed as a function of the velocity (L ˙) and acceleration (L ̈) of L besides rapidly changing state variables like effective temperature (T ) and L itself. The force is now a sum of nonadiabatic (NAD) and adiabatic contributions with the former caused by particles moving synchronously with kinetics of L and the latter by ideal bulk particles insensitive to such a kinetics. The ratio of NAD and adiabatic contributions does not depend on the particle number (N ) in the case of the soft-wall confinement, whereas such a ratio is controllable in the case of hard-wall confinement. We also reveal the condition when the NAD contribution overwhelms the adiabatic one and thoroughly changes the standard form of the equilibrium equation of states.

  13. The role of fragmentation mechanism in large-scale vapor explosions

    International Nuclear Information System (INIS)

    Liu, Jie

    2003-01-01

    A non-equilibrium, multi-phase, multi-component code PROVER-I is developed for propagation phase of vapor explosion. Two fragmentation models are used. The hydrodynamic fragmentation model is the same as Fletcher's one. A new thermal fragmentation model is proposed with three kinds of time scale for modeling instant fragmentation, spontaneous nucleation fragmentation and normal boiling fragmentation. The role of fragmentation mechanisms is investigated by the simulations of the pressure wave propagation and energy conversion ratio of ex-vessel vapor explosion. The spontaneous nucleation fragmentation results in a much higher pressure peak and a larger energy conversion ratio than hydrodynamic fragmentation. The instant fragmentation gives a slightly larger energy conversion ratio than spontaneous nucleation fragmentation, and the normal boiling fragmentation results in a smaller energy conversion ratio. The detailed analysis of the structure of pressure wave makes it clear that thermal detonation exists only under the thermal fragmentation circumstance. The high energy conversion ratio is obtained in a small vapor volume fraction. However, in larger vapor volume fraction conditions, the vapor explosion is weak. In a large-scale vapor explosion, the hydrodynamic fragmentation is essential when the pressure wave becomes strong, so a small energy conversion ratio is expected. (author)

  14. Storm-associated variations of equatorially mirroring ring current protons, 1--800 keV, at constant first adiabatic invariant

    International Nuclear Information System (INIS)

    Lyons, L.R.; Williams, D.J.

    1976-01-01

    Explorer 45 observations of ring current protons mirroring near the equator, 1--800 keV, are presented at constant first adiabatic invariant μ throughout the period of the December 17, 1971, geomagnetic storm. To obtain μ, simultaneous magnetic field and particle observations are used. Particle deceleration in response to the storm time magnetic field decrease causes ring current measurements viewed at constant energy to underestimate the storm time increase in proton intensities at energies approximately-less-than200 keV. This adiabatic deceleration also accounts for the large flux decreases observed at energies approximately-greater-than200 keV during the storm, in contradiction with previous results (Soraas and Davis, 1968) obtained using a model for the storm time magnetic field

  15. Combinatorial explosion in model gene networks

    Science.gov (United States)

    Edwards, R.; Glass, L.

    2000-09-01

    The explosive growth in knowledge of the genome of humans and other organisms leaves open the question of how the functioning of genes in interacting networks is coordinated for orderly activity. One approach to this problem is to study mathematical properties of abstract network models that capture the logical structures of gene networks. The principal issue is to understand how particular patterns of activity can result from particular network structures, and what types of behavior are possible. We study idealized models in which the logical structure of the network is explicitly represented by Boolean functions that can be represented by directed graphs on n-cubes, but which are continuous in time and described by differential equations, rather than being updated synchronously via a discrete clock. The equations are piecewise linear, which allows significant analysis and facilitates rapid integration along trajectories. We first give a combinatorial solution to the question of how many distinct logical structures exist for n-dimensional networks, showing that the number increases very rapidly with n. We then outline analytic methods that can be used to establish the existence, stability and periods of periodic orbits corresponding to particular cycles on the n-cube. We use these methods to confirm the existence of limit cycles discovered in a sample of a million randomly generated structures of networks of 4 genes. Even with only 4 genes, at least several hundred different patterns of stable periodic behavior are possible, many of them surprisingly complex. We discuss ways of further classifying these periodic behaviors, showing that small mutations (reversal of one or a few edges on the n-cube) need not destroy the stability of a limit cycle. Although these networks are very simple as models of gene networks, their mathematical transparency reveals relationships between structure and behavior, they suggest that the possibilities for orderly dynamics in such

  16. Technology of Rock Destruction by Combined Explosion-Mechanical Load

    Directory of Open Access Journals (Sweden)

    Oleg M. Terentiev

    2017-10-01

    Full Text Available Background. Rock drilling is characterized by an energy capacity of more than 120 kWh/m3. This is due to the fact that about 90 % of the energy is expended on the “preparation” of rocks for destruction. This study proposes to combine explosive and mechanical loads to reduce specific energy consumption of rock destruction. Objective. The aim of the paper is energy effective technology development for rock destruction by combined explosive-mechanical loads. Methods. Analytical studies; regression analysis; math modeling; experimental research; technical and economic analysis. Results. Specific energy decreasing for explosive-mechanical rock drilling by 4–16 % was experimentally proved. Conclusions. As a result of the implementation of explosive-mechanical rock drilling on the created full-sized experimental device, the efficiency coefficient increased from 77 to 80 %.

  17. Second Law Violation By Magneto-Caloric Effect Adiabatic Phase Transition of Type I Superconductive Particles

    Directory of Open Access Journals (Sweden)

    Peter Keefe

    2004-03-01

    Full Text Available Abstract: The nature of the thermodynamic behavior of Type I superconductor particles, having a cross section less than the Ginzburg-Landau temperature dependent coherence length is discussed for magnetic field induced adiabatic phase transitions from the superconductive state to the normal state. Argument is advanced supporting the view that when the adiabatic magneto-caloric process is applied to particles, the phase transition is characterized by a decrease in entropy in violation of traditional formulations of the Second Law, evidenced by attainment of a final process temperature below that which would result from an adiabatic magneto-caloric process applied to bulk dimensioned specimens.

  18. Energy-Saving Benefits of Adiabatic Humidification in the Air Conditioning Systems of Semiconductor Cleanrooms

    Directory of Open Access Journals (Sweden)

    Min-Suk Jo

    2017-11-01

    Full Text Available This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1 CASE 1: a make-up air unit (MAU with a steam humidifier, a dry cooling coil (DCC, and a fan filter unit (FFU; (2 CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3 CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU.

  19. High temperature and dynamic testing of AHSS for an analytical description of the adiabatic cutting process

    Science.gov (United States)

    Winter, S.; Schmitz, F.; Clausmeyer, T.; Tekkaya, A. E.; F-X Wagner, M.

    2017-03-01

    In the automotive industry, advanced high strength steels (AHSS) are widely used as sheet part components to reduce weight, even though this leads to several challenges. The demand for high-quality shear cutting surfaces that do not require reworking can be fulfilled by adiabatic shear cutting: High strain rates and local temperatures lead to the formation of adiabatic shear bands (ASB). While this process is well suited to produce AHSS parts with excellent cutting surface quality, a fundamental understanding of the process is still missing today. In this study, compression tests in a Split-Hopkinson Pressure Bar with an initial strain rate of 1000 s-1 were performed in a temperature range between 200 °C and 1000 °C. The experimental results show that high strength steels with nearly the same mechanical properties at RT may possess a considerably different behavior at higher temperatures. The resulting microstructures after testing at different temperatures were analyzed by optical microscopy. The thermo-mechanical material behavior was then considered in an analytical model. To predict the local temperature increase that occurs during the adiabatic blanking process, experimentally determined flow curves were used. Furthermore, the influence of temperature evolution with respect to phase transformation is discussed. This study contributes to a more complete understanding of the relevant microstructural and thermo-mechanical mechanisms leading to the evolution of ASB during cutting of AHSS.

  20. Simulation of first SERENA KROTOS steam explosion experiment

    International Nuclear Information System (INIS)

    Leskovar, Matjaz; Ursic, Mitja

    2009-01-01

    A steam explosion may occur when, during a severe reactor accident, the molten core comes into contact with the coolant water. A strong enough steam explosion in a nuclear power plant could jeopardize the containment integrity and so lead to a direct release of radioactive material to the environment. To resolve the open issues in steam explosion understanding and modeling, the OECD program SERENA Phase 2 was launched at the end of year 2007, focusing on nuclear applications. SERENA comprises an experimental program, which is being carried out in the complementary KROTOS and TROI corium facilities, accompanied by a comprehensive analytical program, where also pre- and post-test calculations are foreseen. In the paper the sensitivity post-test calculations of the first SERENA KROTOS experiment KS-1, which were performed with the code MC3D, are presented and discussed. Since the results of the SERENA tests are restricted to SERENA members, only the various calculation results are given, not comparing them to experimental measurements. Various premixing and explosion simulations were performed on a coarse and a fine numerical mesh, applying two different jet breakup models (global, local) and varying the minimum bubble diameter in the explosion simulations (0.5 mm, 5 mm). The simulations revealed that all varied parameters have a significant influence on the calculation results, as was expected since the fuel coolant interaction process is a highly complex phenomenon. The results of the various calculations are presented in comparison and the observed differences are discussed and explained. (author)