Relaxation and self-organization in two-dimensional plasma and neutral fluid flow systems
International Nuclear Information System (INIS)
Das, Amita
2008-01-01
Extensive numerical studies in the framework of a simplified two-dimensional model for neutral and plasma fluid for a variety of initial configurations and for both decaying and driven cases are carried out to illustrate relaxation toward a self-organized state. The dynamical model equation constitutes a simple choice for this purpose, e.g., the vorticity equation of the Navier-Stokes dynamics for the incompressible neutral fluids and the Hasegawa-Mima equation for plasma fluid flow system. Scatter plots are employed to observe a development of functional relationship, if any, amidst the generalized vorticity and its Laplacian. It is seen that they do not satisfy a linear relationship as the well known variational approach of enstrophy minimization subject to constancy of the energy integral for the two-dimensional (2D) system suggests. The observed nonlinear functional relationship is understood by separating the contribution to the scatter plot from spatial regions with intense vorticity patches and those of the background flow region where the background vorticity is weak or absent altogether. It is shown that such a separation has close connection with the known exact analytical solutions of the system. The analytical solutions are typically obtained by assuming a finite source of vorticity for the inner core of the localized structure, which is then matched with the solution in the outer region where vorticity is chosen to be zero. The work also demonstrates that the seemingly ad hoc choice of the linear vorticity source function for the inner region is in fact consistent with the self-organization paradigm of the 2D systems
The Fundamental Solution and Its Role in the Optimal Control of Infinite Dimensional Neutral Systems
International Nuclear Information System (INIS)
Liu Kai
2009-01-01
In this work, we shall consider standard optimal control problems for a class of neutral functional differential equations in Banach spaces. As the basis of a systematic theory of neutral models, the fundamental solution is constructed and a variation of constants formula of mild solutions is established. We introduce a class of neutral resolvents and show that the Laplace transform of the fundamental solution is its neutral resolvent operator. Necessary conditions in terms of the solutions of neutral adjoint systems are established to deal with the fixed time integral convex cost problem of optimality. Based on optimality conditions, the maximum principle for time varying control domain is presented. Finally, the time optimal control problem to a target set is investigated
International Nuclear Information System (INIS)
Liu, Wei; Ai, Zhihui; Zhang, Lizhi
2012-01-01
Highlights: ► Remove RhB by a novel 3D-E-Fenton system using foam nickel as particle electrodes. ► The 3D-E-Fenton system exhibit much higher RhB removal efficiency than the counterpart 3D-E and E-Fenton system. ► Foam nickel as a particle electrode displays good oxygen reduction activity. ► The performance of RhB removal was optimized by some operating parameters and the optimization pH was the neutral. - Abstract: In this work, we demonstrate a novel three-dimensional electro-Fenton system (3D-E-Fenton) for wastewater treatment with foam nickel, activated carbon fiber and Ti/RuO 2 –IrO 2 as the particle electrodes, the cathode, and the anode respectively. This 3D-E-Fenton system could exhibit much higher rhodamine B removal efficiency (99%) than the counterpart three-dimensional electrochemical system (33%) and E-Fenton system (19%) at neutral pH in 30 min. The degradation efficiency enhancement was attributed to much more hydroxyl radicals generated in the 3D-E-Fenton system because foam nickel particle electrodes could activate molecular oxygen to produce ·O 2 − via a single-electron transfer pathway to subsequently generate more H 2 O 2 and hydroxyl radicals. This is the first observation of molecular oxygen activation over the particle electrodes in the three-dimensional electrochemical system. These interesting findings could provide some new insight on the development of high efficient E-Fenton system for wastewater treatment at neutral pH.
International Nuclear Information System (INIS)
Mondino, P.L.; Di Pietro, E.; Bayetti, P.
1999-01-01
The Neutral Beam (NB) system for the International Thermonuclear Experimental Reactor (ITER) has reached a high degree of integration with the tokamak and with the rest of the plant. Operational requirements and maintainability have been considered in the design. The paper considers the integration with the tokamak, discusses design improvements which appear necessary and finally notes R and D progress in key areas. (author)
Three-dimensional calculations of charge neutralization by neutral gas release
International Nuclear Information System (INIS)
Mandell, M.J.; Jongeward, G.A.; Katz, I.
1993-01-01
There have been numerous observations of high rocket or spacecraft potentials, both positive and negative, and both naturally and artificially induced, being neutralized during thruster firings. Two current studies, CHARGE-2B (positive polarity) and SPEAR3 (negative polarity), attempt a more systematic exploration of this phenomenon. The authors present here calculations performed in support of the SPEAR-3 program. (1) Conventional phenomenology of breakdown is applied to the three-dimensional system formed by the electrostatic potential and plume density fields. Using real cross sections, they calculate the paths along which the nozzle plume can support breakdown. This leads to a recommendation that the higher flow rate on SPEAR-3 be 2 g/s of argon, equal to the CHARGE-2B flow rate. (2) In a laboratory chamber, conditions (pressure of ∼ 2 x 10 - 5 torr) favor breakdown of the positive (electron-collecting) sheath for SPEAR-3 geometry. Three-dimensional calculations illustrate the evolution of the space charge and potential structure during the breakdown process. These calculations demonstrate the ability to apply accepted phenomenology to real systems with three dimensional electrostatic potential fields, space charge fields, and neutral density fields, including magnetic field effects and real cross-section data
Controllability Problem of Fractional Neutral Systems: A Survey
Directory of Open Access Journals (Sweden)
Artur Babiarz
2017-01-01
Full Text Available The following article presents recent results of controllability problem of dynamical systems in infinite-dimensional space. Generally speaking, we describe selected controllability problems of fractional order systems, including approximate controllability of fractional impulsive partial neutral integrodifferential inclusions with infinite delay in Hilbert spaces, controllability of nonlinear neutral fractional impulsive differential inclusions in Banach space, controllability for a class of fractional neutral integrodifferential equations with unbounded delay, controllability of neutral fractional functional equations with impulses and infinite delay, and controllability for a class of fractional order neutral evolution control systems.
PLT neutral beam injection systems
International Nuclear Information System (INIS)
Menon, M.M.; Barber, G.C.; Blue, C.W.
1979-01-01
A brief description of the Princeton Large Torus (PLT) neutral beam injection system is given and its performance characteristics are outlined. A detailed operational procedure is included, as are some tips on troubleshooting. Proper operation of the source is shown to be a crucial factor in system performance
ITER Neutral Beam Injection System
International Nuclear Information System (INIS)
Ohara, Yoshihiro; Tanaka, Shigeru; Akiba, Masato
1991-03-01
A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)
Two dimensional neutral transport analysis in tokamak plasma
International Nuclear Information System (INIS)
Shimizu, Katsuhiro; Azumi, Masafumi
1987-02-01
Neutral particle influences the particle and energy balance, and play an important role on sputtering impurity and the charge exchange loss of neutral beam injection. In order to study neutral particle behaviour including the effects of asymmetric source and divertor configuration, the two dimensional neutral transport code has been developed using the Monte-Carlo techniques. This code includes the calculation of the H α radiation intensity based on the collisional-radiation model. The particle confinement time of the joule heated plasma in JT-60 tokamak is evaluated by comparing the calculated H α radiation intensity with the experimental data. The effect of the equilibrium on the neutral density profile in high-β plasma is also investigated. (author)
TFTR neutral beam power system
International Nuclear Information System (INIS)
Deitz, A.; Murray, H.; Winje, R.
1977-01-01
The TFTR NB System will be composed of four beam lines, each containing three ion sources presently being developed for TFTR by the Lawrence Berkeley Laboratories (LBL). The Neutral Beam Power System (NBPS) will provide the necessary power required to operate these Ion Sources in both an experimental or operational mode as well as test mode. This paper describes the technical as well as the administrative/management aspects involved in the development and building of this system. The NBPS will combine the aspects of HV pulse (120 kV) and long pulse width (0.5 sec) together to produce a high power system that is unique in the Electrical Engineering field
The three-dimensional, discrete ordinates neutral particle transport code TORT: An overview
International Nuclear Information System (INIS)
Azmy, Y.Y.
1996-01-01
The centerpiece of the Discrete Ordinates Oak Ridge System (DOORS), the three-dimensional neutral particle transport code TORT is reviewed. Its most prominent features pertaining to large applications, such as adjustable problem parameters, memory management, and coarse mesh methods, are described. Advanced, state-of-the-art capabilities including acceleration and multiprocessing are summarized here. Future enhancement of existing graphics and visualization tools is briefly presented
TFTR neutral beam injection system conceptual design
International Nuclear Information System (INIS)
1975-01-01
Three subsystems are described in the following chapters: (1) Neutral Beam Injection Line; (2) Power Supplies; and (3) Controls. Each chapter contains two sections: (1) Functions and Design Requirements; this is a brief listing of the requirements of components of the subsystem. (2) Design Description; this section describes the design and cost estimates. The overall performance requirements of the neutral beam injection system are summarized. (MOW)
ITER neutral beam system US conceptual design
International Nuclear Information System (INIS)
Purgalis, P.
1990-09-01
In this document we present the US conceptual design of a neutral beam system for International Thermonuclear Experimental Reactor (ITER). The design incorporates a barium surface conversion D - source feeding a linear array of accelerator channels. The system uses a dc accelerator with electrostatic quadrupoles for strong focusing. A high voltage power supply that is integrated with the accelerator is presented as an attractive option. A gas neutralizer is used and residual ions exiting the neutralizer are deflected to water-cooled dumps. Cryopanels are located at the accelerator exit to pump excess gas from the source and the neutralizer, and in the ion dump cavity to pump re-neutralized ions and neutralizer gas. All the above components are packaged in compact identical, independent modules which can be removed for remote maintenance. The neutral beam system delivers 75 MW of DO at 1.3 MeV, into three ports with a total of 9 modules arranged in stacks of three modules per port . To increase reliability each module is designed to deliver up to 10 MW; this allows eight modules operating at partial capacity to deliver the required power in the event one module is out of service, and provides 20% excess capacity to improve availability. Radiation protection is provided by shielding and by locating critical components in the source and accelerator 46.5 m from the torus centerline. Neutron shielding in the drift duct and neutralizer provides the added feature of limiting conductance and thus reducing gas flow to and from the torus
Neutral beam data systems at ORNL
International Nuclear Information System (INIS)
Stewart, C.R.
1982-01-01
A control system for neutral injection beam lines has been designed, implemented, and used with much success. Despite the problems with very high power levels this system is very successful in relieving the operators burdens of slow conditioning, data recording, and mode switching. The use of computer control with multiple beam lines now appears very promising
Simplified Stability Criteria for Delayed Neutral Systems
Directory of Open Access Journals (Sweden)
Xinghua Zhang
2014-01-01
Full Text Available For a class of linear time-invariant neutral systems with neutral and discrete constant delays, several existing asymptotic stability criteria in the form of linear matrix inequalities (LMIs are simplified by using matrix analysis techniques. Compared with the original stability criteria, the simplified ones include fewer LMI variables, which can obviously reduce computational complexity. Simultaneously, it is theoretically shown that the simplified stability criteria and original ones are equivalent; that is, they have the same conservativeness. Finally, a numerical example is employed to verify the theoretic results investigated in this paper.
Neutral particle beam distributed data acquisition system
International Nuclear Information System (INIS)
Daly, R.T.; Kraimer, M.R.; Novick, A.H.
1987-01-01
A distributed data acquisition system has been designed to support experiments at the Argonne Neutral Particle Beam Accelerator. The system uses a host VAXstation II/GPX computer acting as an experimenter's station linked via Ethernet with multiple MicroVAX IIs and rtVAXs dedicated to acquiring data and controlling hardware at remote sites. This paper describes the hardware design of the system, the applications support software on the host and target computers, and the real-time performance
Development of KSTAR Neutral Beam Heating System
Energy Technology Data Exchange (ETDEWEB)
Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)
2007-10-15
The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.
Oscillations of neutral B mesons systems
Boucrot, J.
1999-01-01
The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is
Neutral Beam Power System for TPX
International Nuclear Information System (INIS)
Ramakrishnan, S.; Bowen, O.N.; O'Conner, T.; Edwards, J.; Fromm, N.; Hatcher, R.; Newman, R.; Rossi, G.; Stevenson, T.; von Halle, A.
1993-01-01
The Tokamak Physics Experiment (TPX) will utilize to the maximum extent the existing Tokamak Fusion Test Reactor (TFTR) equipment and facilities. This is particularly true for the TFTR Neutral Beam (NB) system. Most of the NB hardware, plant facilities, auxiliary sub-systems, power systems, service infrastructure, and control systems can be used as is. The major changes in the NB hardware are driven by the new operating duty cycle. The TFTR Neutral Beam was designed for operation of the Sources for 2 seconds every 150 seconds. The TPX requires operation for 1000 seconds every 4500 seconds. During the Conceptual Design Phase of TPX every component of the TFTR NB Electrical Power System was analyzed to verify whether the equipment can meet the new operational requirements with our without modifications. The Power System converts 13.8 kV prime power to controlled pulsed power required at the NB sources. The major equipment involved are circuit breakers, auto and rectifier transformers surge suppression components, power tetrodes, HV Decks, and HVDC power transmission to sources. Thermal models were developed for the power transformers to simulate the new operational requirements. Heat runs were conducted for the power tetrodes to verify capability. Other components were analyzed to verify their thermal limitations. This paper describes the details of the evaluation and redesign of the electrical power system components to meet the TPX operational requirements
Neutral beam system for an ignition tokamak
International Nuclear Information System (INIS)
Fasolo, J.; Fuja, R.; Jung, J.; Moenich, J.; Norem, J.; Praeg, W.; Stevens, H.
1978-01-01
We have attempted to make detailed designs of several neutral beam systems which would be applicable to a large machine, e.g. an ITR (Ignition Test Reactor), EPR (Experimental Power Reactor), or reactor. Detailed studies of beam transport to the reactor and neutron transport from the reactor have been made. We have also considered constraints imposed by the neutron radiation environment in the injectors, and the resulting shielding, radiation-damage, and maintenance problems. The effects of neutron heat loads on cryopanels and ZrAl getter panels have been considered. Design studies of power supplies, vacuum systems, bending magnets, and injector layouts are in progress and will be discussed
TFTR neutral-beam power system
International Nuclear Information System (INIS)
Winje, R.A.
1982-10-01
The TFTR Neutral Beam Power System (NBPS) consists of the accelerator grid power supply and the auxiliary power supplies required to operate the TFTR 120-keV ion sources. The current configuration of the NBPS including the 11-MVA accelerator grid power supply and the Arc and Filament power supplies isolated for operation at accelerator grid voltages up to 120 kV, is described. The prototype NBPS has been assembled at the Princeton Plasma Physics Laboratory and has been operated. The results of the initial operation and the description and resolution of some of the technical problems encountered during the commissioning tests are presented
Three dimensional system integration
Papanikolaou, Antonis; Radojcic, Riko
2010-01-01
Three-dimensional (3D) integrated circuit (IC) stacking is the next big step in electronic system integration. It enables packing more functionality, as well as integration of heterogeneous materials, devices, and signals, in the same space (volume). This results in consumer electronics (e.g., mobile, handheld devices) which can run more powerful applications, such as full-length movies and 3D games, with longer battery life. This technology is so promising that it is expected to be a mainstream technology a few years from now, less than 10-15 years from its original conception. To achieve thi
Additional neutral vector boson in the 7-dimensional theory of gravy-electro-weak interactions
International Nuclear Information System (INIS)
Gavrilov, V.R.
1988-01-01
Possibilities of manifestation of an additional neutron vector boson, the existence of which is predicted by the 7-dimensional theory of gravy-electro-weak interactions, are analyzed. A particular case of muon neutrino scattering on a muon is considered. In this case additional neutral current manifests both at high and at relatively low energies of particle collisions
The Bohr-Sommerfeld quantization of n-dimensional neutral and charged pulsons
International Nuclear Information System (INIS)
Bogolubsky, I.L.
1978-01-01
The spectrum of masses of 1) neutral and 2) having elementary charge Q=1 of n-dimensional pulsons (i.e., localized oscillating extended solutions) is found by numerical integration using a computer in the framework of the Klein-Gordon equation with the logarithmic nonlinearity. Computer experiments point out that the pulsons under consideration are apparently stable at any n
46 CFR 183.376 - Grounded distribution systems (neutral grounded).
2010-10-01
....376 Section 183.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency power...
46 CFR 120.376 - Grounded distribution systems (Neutral grounded).
2010-10-01
....376 Section 120.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each...
International Nuclear Information System (INIS)
Voloschenko, A.M.; Gukov, S.V.; Kryuchkov, V.P.; Dubinin, A.A.; Sumaneev, O.V.
2005-01-01
The CNCSN package is composed of the following codes: -) KATRIN-2.0: a three-dimensional neutral and charged particle transport code; -) KASKAD-S-2.5: a two-dimensional neutral and charged particle transport code; -) ROZ-6.6: a one-dimensional neutral and charged particle transport code; -) ARVES-2.5: a preprocessor for the working macroscopic cross-section format FMAC-M for transport calculations; -) MIXERM: a utility code for preparing mixtures on the base of multigroup cross-section libraries in ANISN format; -) CEPXS-BFP: a version of the Sandia National Lab. multigroup coupled electron-photon cross-section generating code CEPXS, adapted for solving the charged particles transport in the Boltzmann-Fokker-Planck formulation with the use of discrete ordinate method; -) SADCO-2.4: Institute for High-Energy Physics modular system for generating coupled nuclear data libraries to provide high-energy particles transport calculations by multigroup method; -) KATRIF: the post-processor for the KATRIN code; -) KASF: the post-processor for the KASKAD-S code; and ROZ6F: the post-processor for the ROZ-6 code. The coding language is Fortran-90
Design of a negative ion neutral beam system for TNS
International Nuclear Information System (INIS)
Easoz, J.R.
1978-05-01
A conceptual design of a neutral beam line based on the neutralization of negative deuterium ions is presented. This work is a detailed design of a complete neutral beam line based on using negative ions from a direct extraction source. Anticipating major technological advancements, beam line components have been scaled including the negative ion sources and components for the direct energy recovery of charged beams and high speed cryogenic pumping. With application to the next step in experimental fusion reactors (TNS), the neutral beam injector system that has been designed provides 10 MW of 200 keV neutral deuterium atoms. Several arms are required for plasma ignition
DANTSYS: a system for deterministic, neutral particle transport calculations
Energy Technology Data Exchange (ETDEWEB)
Alcouffe, R.E.; Baker, R.S.
1996-12-31
The THREEDANT code is the latest addition to our system of codes, DANTSYS, which perform neutral particle transport computations on a given system of interest. The system of codes is distinguished by geometrical or symmetry considerations. For example, ONEDANT and TWODANT are designed for one and two dimensional geometries respectively. We have TWOHEX for hexagonal geometries, TWODANT/GQ for arbitrary quadrilaterals in XY and RZ geometry, and THREEDANT for three-dimensional geometries. The design of this system of codes is such that they share the same input and edit module and hence the input and output is uniform for all the codes (with the obvious additions needed to specify each type of geometry). The codes in this system are also designed to be general purpose solving both eigenvalue and source driven problems. In this paper we concentrate on the THREEDANT module since there are special considerations that need to be taken into account when designing such a module. The main issues that need to be addressed in a three-dimensional transport solver are those of the computational time needed to solve a problem and the amount of storage needed to accomplish that solution. Of course both these issues are directly related to the number of spatial mesh cells required to obtain a solution to a specified accuracy, but is also related to the spatial discretization method chosen and the requirements of the iteration acceleration scheme employed as will be noted below. Another related consideration is the robustness of the resulting algorithms as implemented; because insistence on complete robustness has a significant impact upon the computation time. We address each of these issues in the following through which we give reasons for the choices we have made in our approach to this code. And this is useful in outlining how the code is evolving to better address the shortcomings that presently exist.
Three-Dimensional Neutral Transport Simulations of Gas Puff Imaging Experiments
International Nuclear Information System (INIS)
Stotler, D.P.; DIppolito, D.A.; LeBlanc, B.; Maqueda, R.J.; Myra, J.R.; Sabbagh, S.A.; Zweben, S.J.
2003-01-01
Gas Puff Imaging (GPI) experiments are designed to isolate the structure of plasma turbulence in the plane perpendicular to the magnetic field. Three-dimensional aspects of this diagnostic technique as used on the National Spherical Torus eXperiment (NSTX) are examined via Monte Carlo neutral transport simulations. The radial width of the simulated GPI images are in rough agreement with observations. However, the simulated emission clouds are angled approximately 15 degrees with respect to the experimental images. The simulations indicate that the finite extent of the gas puff along the viewing direction does not significantly degrade the radial resolution of the diagnostic. These simulations also yield effective neutral density data that can be used in an approximate attempt to infer two-dimensional electron density and temperature profiles from the experimental images
New stability and stabilization for switched neutral control systems
International Nuclear Information System (INIS)
Xiong Lianglin; Zhong Shouming; Ye Mao; Wu Shiliang
2009-01-01
This paper concerns stability and stabilization issues for switched neutral systems and presents new classes of piecewise Lyapunov functionals and multiple Lyapunov functionals, based on which, two new switching rules are introduced to stabilize the neutral systems. One switching rule is designed from the solution of the so-called Lyapunov-Metzler linear matrix inequalities. The other is based on the determination of average dwell time computed from a new class of linear matrix inequalities (LMIs). And then, state-feedback control is derived for the switched neutral control system mainly based on the state switching rules. Finally, three examples are given to demonstrate the effectiveness of the proposed method.
Neutral beam systems for the magnetic fusion program
International Nuclear Information System (INIS)
Beal, J.W.; Staten, H.S.
1977-01-01
The attainment of economic, safe fusion power has been described as the most sophisticated scientific problem ever attacked by mankind. The presently established goal of the magnetic fusion program is to develop and demonstrate pure fusion central electric power stations for commercial applications. Neutral beam heating systems are a basic component of the tokamak and mirror experimental fusion plasma confinement devices. The requirements placed upon neutral beam heating systems are reviewed. The neutral beam systems in use or being developed are presented. Finally, the needs of the future are discussed
Testing general relativity with the neutral kaon system
International Nuclear Information System (INIS)
Chardin, G.
1992-01-01
The arguments favouring gravitation as the 'Master Arrow of Time' are briefly reviewed and the possibility that CP violation observed in the neutral kaon system may be explained by a violation of the Equivalence Principle is discussed. It was attempted to demonstrate that the arguments against antigravity should be reconsidered and that the neutral kaon system, the most sensitive interferometric system at the disposal, is ideal to test the existence of antigravity. (R.P.) 33 refs
A new method of solution for one-dimensional quasi-neutral bounded plasmas
Kamran, M.; Kuhn, S.
2010-08-01
A new method is proposed for calculating the potential distribution Φ(z) in a one-dimensional quasi-neutral bounded plasma; Φ(z) is assumed to satisfy a quasi-neutrality condition (plasma equation) of the form ni{Φ(z)} = ne(Φ), where the electron density ne is a given function of Φ and the ion density ni is expressed in terms of trajectory integrals of the ion kinetic equation. While previous methods relied on formally solving a global integral equation (Riemann, Phys. Plasmas, vol. 13, 2006, paper no. 013503; Kos et al., Phys. Plasmas, vol. 16, 2009, paper no. 093503), the present method is characterized by piecewise analytic solution of the plasma equation in reasonably small intervals of z. As a first concrete application, Φ(z) is found analytically through order z4 near the center of a collisionless Tonks-Langmuir discharge with a cold-ion source.
Direct evidence for T violation in the neutral kaon system
Adler, R; Angelopoulos, Angelos; Aspostolakis, A; Aslanides, Elie; Backenstoss, Gerhard; Bee, C P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Bula, C; Carlson, P J; Carroll, M; Carvalho, J; Cawley, E; Charalambous, S; Chardalas, M; Chardin, G; Chertok, M B; Cody, A; Danielsson, M; Dedoussis, S; Dejardin, M; Derré, J; Duclos, J; Ealet, A; Eckart, B; Eleftheriadis, C; Evangelou, I; Faravel, L; Fassnacht, P; Faure, J L; Felder, C; Ferreira-Marques, R; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Garreta, D; Gerber, H J; Go, A; Guyot, C; Haselden, A; Hayman, P J; Henry-Coüannier, F; Hollander, R W; Hubert, E; Jon-And, K; Kettle, P R; Kochowski, Claude; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Liolios, A; Machado, E; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Nakada, Tatsuya; Onofre, A; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Pinto da Cunha, J; Policarpo, Armando; Polivka, G; Rickenbach, R; Roberts, B L; Rozaki, E; Ruf, T; Sakelliou, L; Sanders, P; Santoni, C; Sarigiannis, K; Schäfer, M; Schaller, L A; Schopper, A; Schune, P; Soares, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; Triantis, F A; Van Beveren, E; van Eijk, C W E; Varner, G S; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Yéche, C; Zavrtanik, D; Zimmerman, D
1995-01-01
We present the first direct observation of T violation in the neutral kaon system, showing a positive signal with a significance of more than two standard deviations. The result does not rely on the validity of the CPT theorem.
Direct evidence for T violation in the neutral kaon system
International Nuclear Information System (INIS)
Dejardin, M.; Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Bertin, V.; Behnke, O.; Benelli, A.
1995-01-01
The first direct observation of T violation in the neutral kaon system, is presented showing a positive signal with a significance of more than two standard deviations. The results does not rely on the validity of the CPT theorem. (author)
Neutral-beam systems for magnetic-fusion reactors
International Nuclear Information System (INIS)
Fink, J.H.
1981-01-01
Neutral beams for magnetic fusion reactors are at an early stage of development, and require considerable effort to make them into the large, reliable, and efficient systems needed for future power plants. To optimize their performance to establish specific goals for component development, systematic analysis of the beamlines is essential. Three ion source characteristics are discussed: arc-cathode life, gas efficiency, and beam divergence, and their significance in a high-energy neutral-beam system is evaluated
Optics of ion beams for the neutral beam injection system on HL-2A Tokamak
Energy Technology Data Exchange (ETDEWEB)
Zou, G. Q.; Lei, G. J.; Cao, J. Y.; Duan, X. R. [Southwestern Institute of Physics, Chengdu, 610041 (China)
2012-07-15
The ion beam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ion beam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ion beam optics, the application of a small pre-acceleration voltage ({approx}100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ion beam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.
Optics of ion beams for the neutral beam injection system on HL-2A Tokamak.
Zou, G Q; Lei, G J; Cao, J Y; Duan, X R
2012-07-01
The ion beam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ion beam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ion beam optics, the application of a small pre-acceleration voltage (∼100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ion beam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.
TFTR neutral beam systems conceptual design
International Nuclear Information System (INIS)
1976-03-01
The functions, design requirements, and design descriptions of the injection system are described. Cost summaries are given for each system and subsystem. The costs presented are for: materials procurement; and shipping, assembly, and installation at the Princeton site
Doublet III neutral beam multi-stream command language system
International Nuclear Information System (INIS)
Campbell, L.; Garcia, J.R.
1983-01-01
A multi-stream command language system was developed to provide control of the dual source neutral beam injectors on the Doublet III experiment at GA Technologies Inc. The Neutral Beam command language system consists of three parts: compiler, sequencer, and interactive task. The command language, which was derived from the Doublet III tokamak command language, POPS, is compiled, using a recursive descent compiler, into reverse polish notation instructions which then can be executed by the sequencer task. The interactive task accepts operator commands via a keyboard. The interactive task directs the operation of three input streams, creating commands which are then executed by the sequencer. The streams correspond to the two sources within a Doublet III neutral beam, plus an interactive stream. The sequencer multiplexes the execution of instructions from these three streams. The instructions include reads and writes to an operator terminal, arithmetic computations, intrinsic functions such as CAMAC input and output, and logical instructions. The neutral beam command language system was implemented using Modular Computer Systems (ModComp) Pascal and consists of two tasks running on a ModComp Classic IV computer. The two tasks, the interactive and the sequencer, run independently and communicate using shared memory regions. The compiler runs as an overlay to the interactive task when so directed by operator commands. The system is succesfully being used to operate the three neutral beams on Doublet III
Stability and delay sensitivity of neutral fractional-delay systems.
Xu, Qi; Shi, Min; Wang, Zaihua
2016-08-01
This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.
Performing three-dimensional neutral particle transport calculations on tera scale computers
International Nuclear Information System (INIS)
Woodward, C.S.; Brown, P.N.; Chang, B.; Dorr, M.R.; Hanebutte, U.R.
1999-01-01
A scalable, parallel code system to perform neutral particle transport calculations in three dimensions is presented. To utilize the hyper-cluster architecture of emerging tera scale computers, the parallel code successfully combines the MPI message passing and paradigms. The code's capabilities are demonstrated by a shielding calculation containing over 14 billion unknowns. This calculation was accomplished on the IBM SP ''ASCI-Blue-Pacific computer located at Lawrence Livermore National Laboratory (LLNL)
THREEDANT: A code to perform three-dimensional, neutral particle transport calculations
International Nuclear Information System (INIS)
Alcouffe, R.E.
1994-01-01
The THREEDANT code solves the three-dimensional neutral particle transport equation in its first order, multigroup, discrate ordinate form. The code allows an unlimited number of groups (depending upon the cross section set), angular quadrature up to S-100, and unlimited Pn order again depending upon the cross section set. The code has three options for spatial differencing, diamond with set-to-zero fixup, adaptive weighted diamond, and linear modal. The geometry options are XYZ and RZΘ with a special XYZ option based upon a volume fraction method. This allows objects or bodies of any shape to be modelled as input which gives the code as much geometric description flexibility as the Monte Carlo code MCNP. The transport equation is solved by source iteration accelerated by the DSA method. Both inner and outer iterations are so accelerated. Some results are presented which demonstrate the effectiveness of these techniques. The code is available on several types of computing platforms
CP violation in the neutral kaon system
International Nuclear Information System (INIS)
Aslanides, E.
1994-01-01
A short description of the K 0 system is given in order to review the known and to identify the missing observables. The review of the most recent results and of the experiments in preparation illustrates the complementarity between the classical, regenerator type, studies and the new approach using initially pure K 0 and K-bar 0 beams. (author)
Data acquisition system for medium power neutral beam test facility
International Nuclear Information System (INIS)
Stewart, C.R. Jr.; Francis, J.E. Jr.; Hammons, C.E.; Dagenhart, W.K.
1978-06-01
The Medium Power Neutral Beam Test Facility at Oak Ridge National Laboratory was constructed in order to develop, test, and condition powerful neutral beam lines for the Princeton Large Torus experiment at Princeton Plasma Physics Laboratory. The data acquisition system for the test stand monitors source performance, beam characteristics, and power deposition profiles to determine if the beam line is operating up to its design specifications. The speed of the computer system is utilized to provide near-real-time analysis of experimental data. Analysis of the data is presented as numerical tabulation and graphic display
Data acquisition system for PLT Neutral Beam Test Stand
International Nuclear Information System (INIS)
Francis, J.E. Jr.; Hammons, C.E.
1977-01-01
The PLT Neutral Beam Test Stand at Oak Ridge National Laboratory was constructed to test and condition powerful neutral beam sources for the Princeton Large Torus experiment at Princeton Plasma Physics Laboratory. The data acquisition system for the test stand monitors the beam characteristics and power output to determine if the beam is operating at its design specifications. The high speed of the computer system is utilized to provide near-real-time analysis of experimental data. The analysis of the data is presented as numerical tabulation and graphic display
International Nuclear Information System (INIS)
Barrado, J.M.; Blazquez, J.B.; Perez-Navarro, A.; Zurro, B.
1977-01-01
An one-dimensional model to analyze the neutral atoms penetration into a hot plasma has been introduced in order to get the ionic temperature from the energy distribution of the charge exchange neutrals, which is obtained following a Montecarlo procedure. The model enhances the influence of the non homogeneous charge-exchange and temperature profiles over the energy distribution. It also shows haw the inner neutrals are screened by the plasma external layers and the dependence of the effective temperature on the charge-exchange cross section. Results agree with experimental data and with obtained through some others more elaborated models. (author) [es
Instrumentation system for long-pulse MFTF neutral beams
International Nuclear Information System (INIS)
Risch, D.M.
1981-01-01
The instrumentation system for long pulse neutral beams for MFTFS consists of monitoring and protective circuitry. Global synchronization of high speed monitoring data across twenty-four neutral beams is achieved via an experiment wide fiber optic timing system. Fiber optics are also used as a means of isolating signals at elevated voltages. An excess current monitor, interrupt monitor, sparkdown detector, spot detector and gradient grid ratio detector form the primary protection for the neutral beam source. A unique hierarchical interlocking scheme allows other protective devices to be factored into the shutdown circuitry of the power supply so that the initiating cause of a shutdown can be isolated and even allows some non-critical devices to be safely ignored for a period of time
Manstetten, Paul; Filipovic, Lado; Hössinger, Andreas; Weinbub, Josef; Selberherr, Siegfried
2017-02-01
We present a computationally efficient framework to compute the neutral flux in high aspect ratio structures during three-dimensional plasma etching simulations. The framework is based on a one-dimensional radiosity approach and is applicable to simulations of convex rotationally symmetric holes and convex symmetric trenches with a constant cross-section. The framework is intended to replace the full three-dimensional simulation step required to calculate the neutral flux during plasma etching simulations. Especially for high aspect ratio structures, the computational effort, required to perform the full three-dimensional simulation of the neutral flux at the desired spatial resolution, conflicts with practical simulation time constraints. Our results are in agreement with those obtained by three-dimensional Monte Carlo based ray tracing simulations for various aspect ratios and convex geometries. With this framework we present a comprehensive analysis of the influence of the geometrical properties of high aspect ratio structures as well as of the particle sticking probability on the neutral particle flux.
Very-high-level neutral-beam control system
International Nuclear Information System (INIS)
Elischer, V.; Jacobson, V.; Theil, E.
1981-10-01
As increasing numbers of neutral beams are added to fusion machines, their operation can consume a significant fraction of a facility's total resources. LBL has developed a very high level control system that allows a neutral beam injector to be treated as a black box with just 2 controls: one to set the beam power and one to set the pulse duration. This 2 knob view allows simple operation and provides a natural base for implementing even higher level controls such as automatic source conditioning
Doublet III neutral beam multi-stream command language system
International Nuclear Information System (INIS)
Campbell, L.; Garcia, J.R.
1983-12-01
A multi-stream command language system was developed to provide control of the dual source neutral beam injectors on the Doublet III experiment at GA Technologies Inc. The Neutral Beam command language system consists of three parts: compiler, sequencer, and interactive task. The command language, which was derived from the Doublet III tokamak command language, POPS, is compiled, using a recursive descent compiler, into reverse polish notation instructions which then can be executed by the sequencer task. The interactive task accepts operator commands via a keyboard. The interactive task directs the operation of three input streams, creating commands which are then executed by the sequencer. The streams correspond to the two sources within a Doublet III neutral beam, plus an interactive stream. The sequencer multiplexes the execution of instructions from these three streams. The instructions include reads and writes to an operator terminal, arithmetic computations, intrinsic functions such as CAMAC input and output, and logical instructions. The neutral beam command language system was implemented using Modular Computer Systems (ModComp) Pascal and consists of two tasks running on a ModComp Classic IV computer
Periodic Solutions of a Neutral Diﬀerence System
Directory of Open Access Journals (Sweden)
Sui Sun Cheng
2004-11-01
Full Text Available Suﬃcient conditions in terms of the matrix measure for the periodicsolutions of a neutral type delay diﬀerence system Delta[x(n + c x (n- tau] = A(n,x (n x(n + f (n,x (,n-sigmaare given.
Relative controllability of nonlinear neutral systems with distributed ...
African Journals Online (AJOL)
In this paper we study the relative controllability of nonlinear neutral system with distributed and multiple lumped time varying delays in control. Using Schauder's fixed point theorem sufficient conditions for relative controllability in a given time interval are formulated and proved. Journal of the Nigerian Association of ...
Mechanical engineering problems in the TFTR neutral beam system
International Nuclear Information System (INIS)
Cannon, D.D.; Bryant, E.H.; Johnson, R.L.; Kim, J.; Queen, C.C.; Schilling, G.
1975-01-01
A conceptual design of a prototype beam line for the TFTR Neutral Beam System has been developed. The basic components have been defined, cost estimates prepared, and the necessary development programs identified. Four major mechanical engineering problems, potential solutions and the required development programs are discussed
Violation of Bell's inequality in neutral kaons system
Indian Academy of Sciences (India)
We show by general considerations that it is not possible to test violation of the existing versions of Bell's inequality in entangled neutral kaons system using experimentally accessible thin regenerators. We point out the loophole in the recent argument (A Bramon and M Nowakowski, Phys. Rev. Lett. 83, 1 (1999)) that ...
Violation of Bell's inequality in neutral kaons system
Indian Academy of Sciences (India)
Abstract. We show by general considerations that it is not possible to test violation of the existing versions of Bell's inequality in entangled neutral kaons system using experimentally accessible thin regenerators. We point out the loophole in the recent argument (A Bramon and M Nowakowski,. Phys. Rev. Lett. 83, 1 (1999)) ...
Neutral beam control systems for the Tandem Mirror Experiment
International Nuclear Information System (INIS)
Ross, R.I.
1979-01-01
The Tandem Mirror Experiment (TMX) is presently developing the technology and approaches which will be used in larger fusion systems. This paper describes some of the designs which were used in creating the control system for the TMX neutral beams. To create a system of controls that would work near these large, rapid switching current sources required a mixture of different technologies: fiberoptic data transmission, printed circuit and wirewrap techniques, etc
DEFF Research Database (Denmark)
Choi, Uimin; Lee, June-Seok; Lee, Kyo-Beum
2014-01-01
This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect the neutral-point voltage. The zero...... and medium switching states are employed to help the neutral-point voltage balancing. This method little bit increases the switching events and output total harmonic distortion. However, this method has a strong balancing ability at all regions. Further, it is very simple to implement in both space vector...
Performance of the DIII-D neutral beam injection system
International Nuclear Information System (INIS)
Kim, J.; Callis, R.W.; Colleraine, A.P.; Cummings, J.; Glad, A.S.; Gootgeld, A.M.; Haskovec, J.S.; Hong, R.; Kellman, D.H.; Langhorn, A.R.
1987-01-01
During the upgrade of the Doublet III tokamak, the neutral beam injection system as also modified to accommodate long pulse sources and to utilize the larger entrance apertures to the torus vessel. All four beamlines on DIII-D are now in operation with a total of eight common long pulse sources. These have exhibited easier conditioning and good reproducibility. Performance results of the beamlines and supporting systems are presented, and the observed beam properties are discussed
Long pulse neutral beam system for the Tokamak Physics Experiment
International Nuclear Information System (INIS)
Grisham, L.R.; Bowen, O.N.; Dahlgren, F.; Edwards, J.W.; Kamperschroer, J.; Newman, R.; O'Connor, T.; Ramakrishnan, S.; Rossi, G.; Stevenson, T.; Halle, A. von; Wright, K.E.
1995-01-01
The Tokamak Physics Experiment (TPX) is planned as a long-pulse or steady-state machine to serve as a successor to the Tokamak Fusion Test Reactor (TFTR). The neutral beam component of the heating and current drive systems will be provided by a TFTR beamline modified to allow operation for pulse lengths of 1000s. This paper presents a brief overview of the conceptual design which has been carried out to determine the changes to the beamline and power supply components that will be required to extend the pulse length from its present limitation of 1s at full power. The modified system, like the present one, will be capable of injecting about 8MW of power as neutral deuterium. The initial operation will be with a single beamline oriented co-directional to the plasma current, but the TPX system design is capable of accommodating an additional co-directional beamline and a counter-directional beamline. ((orig.))
International Nuclear Information System (INIS)
Sano, Fumimichi; Obiki, Tokuhiro; Sasaki, Akihiko; Iiyoshi, Atsuo; Uo, Koji
1982-01-01
The hydrogen ion species in a Heliotron E neutral beam injection system of maximum electric power 6.3 MW were analyzed in order to assess the neutral beam power injected into the torus. The masimum p roton ratio of the cylindrical bucket type ion source used was observed to be more than 90 percent assuming that the angular divergences for the respective species in the beam are the same. The experimental data are compared with calculations using a particle balance model. The analysis indicates that the net injection power reaches nearly 2.7 MW at the optimal conditions of the system considering the geometrical limitation of the neutral beam path. (author)
Three-dimensional modeling of the neutral gas depletion effect in a helicon discharge plasma
Kollasch, Jeffrey; Schmitz, Oliver; Norval, Ryan; Reiter, Detlev; Sovinec, Carl
2016-10-01
Helicon discharges provide an attractive radio-frequency driven regime for plasma, but neutral-particle dynamics present a challenge to extending performance. A neutral gas depletion effect occurs when neutrals in the plasma core are not replenished at a sufficient rate to sustain a higher plasma density. The Monte Carlo neutral particle tracking code EIRENE was setup for the MARIA helicon experiment at UW Madison to study its neutral particle dynamics. Prescribed plasma temperature and density profiles similar to those in the MARIA device are used in EIRENE to investigate the main causes of the neutral gas depletion effect. The most dominant plasma-neutral interactions are included so far, namely electron impact ionization of neutrals, charge exchange interactions of neutrals with plasma ions, and recycling at the wall. Parameter scans show how the neutral depletion effect depends on parameters such as Knudsen number, plasma density and temperature, and gas-surface interaction accommodation coefficients. Results are compared to similar analytic studies in the low Knudsen number limit. Plans to incorporate a similar Monte Carlo neutral model into a larger helicon modeling framework are discussed. This work is funded by the NSF CAREER Award PHY-1455210.
Controlling uncertain neutral dynamic systems with delay in control input
International Nuclear Information System (INIS)
Park, Ju H.; Kwon, O.
2005-01-01
This article gives a novel criterion for the asymptotic stabilization of the zero solutions of a class of neutral systems with delays in control input. By constructing Lyapunov functionals, we have obtained the criterion which is expressed in terms of matrix inequalities. The solutions of the inequalities can be easily solved by efficient convex optimization algorithms. A numerical example is included to illustrate the design procedure of the proposed method
Conceptual design for the ZEPHYR neutral-beam injection system
International Nuclear Information System (INIS)
Cooper, W.S.; Elischer, V.P.; Goldberg, D.A.; Hopkins, D.B.; Jacobson, V.L.; Lou, K.H.; Tanabe, J.T.
1981-03-01
In June 1980, the Lawrence Berkeley Laboratory began a conceptual design study for a neutral beam injection system for the ZEPHYR ignition tokamak proposed by the Max-Planck-Institut fur Plasmaphysik in Garching, Germany. The ZEPHYR project was cancelled, and the LBL design effort concluded prematurely in January 1981. This report describes the conceptual design as it existed at that time, and gives brief consideration to a schedule, but does not deal with costs
Stability of neutral type descriptor system with mixed delays
International Nuclear Information System (INIS)
Li Hong; Li Houbiao; Zhong Shouming
2007-01-01
In this paper, the stability problems of general neutral type descriptor system with mixed delays are considered. Some new delay-independent stability and robust stability criteria, which are simpler and less conservative than existing results, are derived in terms of the stability of a new operator I and linear matrix inequalities (LMIs). Therefore, criteria can be easily checked by utilizing the Matlab LMI toolbox
Design of a negative ion neutral beam system for TNS
International Nuclear Information System (INIS)
Easoz, J.R.; Sink, D.A.
1979-01-01
A design is presented that suggests that a negative ion neutral beam based on direct extraction is applicable to TNS, assuming technological advancements in several areas. Improvements in negative ion sources, direct energy conversion of charged beams, and high speed cryogenic pumping are needed. The increase in efficiency over a positive ion system and the encouraging results of the first attempt at a total design justify increased effort in the development of the above mentioned areas
H- beam neutralization measurements in a solenoidal beam transport system
International Nuclear Information System (INIS)
Sherman, J.; Pitcher, E.; Stevens, R.; Allison, P.
1992-01-01
H minus beam space-charge neutralization is measured for 65-mA, 35-keV beams extracted from a circular-aperture Penning surface-plasma source, the small-angle source. The H minus beam is transported to a RFQ matchpoint by a two-solenoid magnet system. Beam noise is typically ±4%. A four-grid analyzer is located in a magnetic-field-free region between the two solenoid magnets. H minus potentials are deduced from kinetic energy measurements of particles (electrons and positive ions) ejected radially from the beam channel by using a griddled energy analyzer. Background neutral gas density is increased by the introduction of additional Xe and Ar gases, enabling the H minus beam to become overneutralized
Development of the TFTR neutral beam injection system
International Nuclear Information System (INIS)
Prichard, B.A. Jr.
1978-01-01
The TFTR Neutral Beam Lines are designed to inject 20 MW of 120 keV neutral deuterium atoms into the plasma. This is accomplished using 12 sources, 65 amperes each, mounted in 4 beam lines. The 120 kV sources are being developed by LBL and a prototype beam line which will be tested at Berkeley is being developed as a cooperative effort by LLL and LBL. The implementation of these beam lines has required the development of several associated pieces of hardware. The control and monitoring of the 12 sources will be done via the TFTR computer control system (CICADA) as will other parts of the machine, and software is being developed to condition and operate the sources automatically. The prototype beam line is scheduled to begin operation in the fall of 1978 and all four production beam lines on TFTR in 1982
TMX-U neutral pressure measurement diagnostic systems
International Nuclear Information System (INIS)
Pickles, W.L.; Allen, S.L.; Hill, D.N.; Hunt, A.L.; Simonen, T.C.
1984-01-01
The Tandem Mirror Experiment-Upgrade (TMX-U) has a large and complex system of Baird Alpert, magnetron, and Penning gauges, in addition to mass spectrometers (RGA), all of which measure neutral pressures in the many internal regions of TMX-U. These pressure measurements are used as part of the confinement physics data base as well as for management of the TMX-U vacuum system. Dynamic pressures are modeled by a coupled-volumes simulation code, which includes wall reflus, getter pumping, and plasma pumping
Non-locality versus entanglement in the neutral kaon system
International Nuclear Information System (INIS)
Ableitinger, A.; Bertlmann, R.A.; Durstberger, K.; Hiesmayr, B.C.; Krammer, P.
2006-01-01
Full text: Particle physics has become an interesting testing ground for fundamental questions of quantum mechanics (QM). The entangled massive meson-antimeson systems are specially suitable as they offer a unique laboratory to test various aspects of particle physics (CP violation, CPT violation, . . . ) as well to test foundations of QM (local realistic theories versus QM, Bell inequalities, decoherence effects, quantum marking and erasure concepts, . . . ). For the neutral kaon system we show that nonlocality detected by the violation of a Bell inequality and entanglement are indeed different concepts. (author)
International Nuclear Information System (INIS)
deVries, G.J.; Chesley, K.L.; Owren, H.M.
1983-12-01
Neutral beam sources, their power supplies and instrumentation can be damaged from high voltage sparkdown or from overheating due to excessive currents. The Neutral Beam Engineering Test Facility (NBETF) in Berkeley has protective electronic hardware that senses a condition outside a safe operating range and generates a response to terminate such a fault condition. A description of this system is presented in this paper. 8 references, 2 figures, 2 tables
4+ Dimensional nuclear systems engineering
International Nuclear Information System (INIS)
Suh, Kune Y.
2009-01-01
Nuclear power plants (NPPs) require massive quantity of data during the design, construction, operation, maintenance and decommissioning stages because of their special features like size, cost, radioactivity, and so forth. The system engineering thus calls for a fully integrated way of managing the information flow spanning their life cycle. This paper proposes digital systems engineering anchored in three dimensional (3D) computer aided design (CAD) models. The signature in the proposal lies with the four plus dimensional (4 + D) Technology TM , a critical know how for digital management. ESSE (Engineering Super Simulation Emulation) features a 4 + D Technology TM for nuclear energy systems engineering. The technology proposed in the 3D space and time plus cost coordinates, i.e. 4 + D, is the backbone of digital engineering in the nuclear systems design and management. Dased on an integrated 3D configuration management system, ESSE consists of solutions JANUS (Junctional Analysis Neodynamic Unit SoftPower), EURUS (Engineering Utilities Research Unit SoftPower), NOTUS (Neosystemic Optimization Technical Unit SoftPower), VENUS (Virtual Engineering Neocybernetic Unit SoftPower) and INUUS (Informative Neographic Utilities Unit SoftPower). NOTUS contributes to reducing the construction cost of the NPPs by optimizing the component manufacturing procedure and the plant construction process. Planning and scheduling construction projects can thus benefit greatly by integrating traditional management techniques with digital process simulation visualization. The 3D visualization of construction processes and the resulting products intrinsically afford most of the advantages realized by incorporating a purely schedule level detail based the 4 + D system. Problems with equipment positioning and manpower congestion in certain areas can be visualized prior to the actual operation, thus preventing accidents and safety problems such as collision between two machines and losses in
Inclusive neutral current ep cross sections with HERA II and two-dimensional unfolding
International Nuclear Information System (INIS)
Fischer, David-Johannes
2011-06-01
In this thesis, the inclusive neutral current ep → eX cross section at small e - scattering angles has been measured using the electromagnetic SpaCal calorimeter in the backward region of the H1 detector. This calorimeter constructed of lead and scintillating fiber was designed to measure the scattered electron with high resolution in both energy and polar angle. The analysis comprises the kinematic range of 0.06 e 2 e 2 2 for the squared momentum exchange. The data sample consists of positron proton collisions of the years 2006 and 2007, adding up to an integrated luminosity of ∝141 pb -1 . Due to the high luminosity of the HERA II run phase the accuracy is no longer limited by the data statistics but rather by the detector resolution and systematics. The migration becomes increasingly influential; an effect which leads to distortions of the measured distribution as well as to statistical correlations between adjacent data points. At this stage, the correction of detector effects as well as the precise determination of statistical correlations become important features of a rigorous error treatment. In this analysis two-dimensional unfolding has been applied. This is a novel approach to H1 inclusive cross section measurements, which are usually based on a bin-by-bin efficiency correction (bin-by-bin method). With unfolding, the detector effect to the measurements is modelled by a linear transformation (''response matrix'') which is used to correct any distortion of the data. The inclusion of off-diagonal elements results in a coherent assessment of the statistical uncertainties and correlations. The model dependence can be optimally evaluated. In this context, the bin-by-bin method can be viewed as an approximation based on a diagonal response matrix. In a scenario of limited detector resolution, the unfolded data distributions will typically exhibit strong fluctuations and correlations between the data points. This issue can be addressed by smoothing
Inclusive neutral current ep cross sections with HERA II and two-dimensional unfolding
Energy Technology Data Exchange (ETDEWEB)
Fischer, David-Johannes
2011-06-15
In this thesis, the inclusive neutral current ep {yields} eX cross section at small e{sup -} scattering angles has been measured using the electromagnetic SpaCal calorimeter in the backward region of the H1 detector. This calorimeter constructed of lead and scintillating fiber was designed to measure the scattered electron with high resolution in both energy and polar angle. The analysis comprises the kinematic range of 0.06 < y{sub e} < 0.6 for the inelasticity and 14 GeV{sup 2} < Q{sub e}{sup 2} < 110 GeV{sup 2} for the squared momentum exchange. The data sample consists of positron proton collisions of the years 2006 and 2007, adding up to an integrated luminosity of {proportional_to}141 pb{sup -1}. Due to the high luminosity of the HERA II run phase the accuracy is no longer limited by the data statistics but rather by the detector resolution and systematics. The migration becomes increasingly influential; an effect which leads to distortions of the measured distribution as well as to statistical correlations between adjacent data points. At this stage, the correction of detector effects as well as the precise determination of statistical correlations become important features of a rigorous error treatment. In this analysis two-dimensional unfolding has been applied. This is a novel approach to H1 inclusive cross section measurements, which are usually based on a bin-by-bin efficiency correction (bin-by-bin method). With unfolding, the detector effect to the measurements is modelled by a linear transformation (''response matrix'') which is used to correct any distortion of the data. The inclusion of off-diagonal elements results in a coherent assessment of the statistical uncertainties and correlations. The model dependence can be optimally evaluated. In this context, the bin-by-bin method can be viewed as an approximation based on a diagonal response matrix. In a scenario of limited detector resolution, the unfolded data distributions will
Expansion of the TFTR neutral beam computer system
International Nuclear Information System (INIS)
McEnerney, J.; Chu, J.; Davis, S.; Fitzwater, J.; Fleming, G.; Funk, P.; Hirsch, J.; Lagin, L.; Locasak, V.; Randerson, L.; Schechtman, N.; Silber, K.; Skelly, G.; Stark, W.
1992-01-01
Previous TFTR Neutral Beam computing support was based primarily on an Encore Concept 32/8750 computer within the TFTR Central Instrumentation, Control and Data Acquisition System (CICADA). The resources of this machine were 90% utilized during a 2.5 minute duty cycle. Both interactive and automatic processes were supported, with interactive response suffering at lower priority. Further, there were additional computing requirements and no cost effective path for expansion within the Encore framework. Two elements provided a solution to these problems: improved price performance for computing and a high speed bus link to the SELBUS. The purchase of a Sun SPARCstation and a VME/SELBUS bus link, allowed offloading the automatic processing to the workstation. This paper describes the details of the system including the performance of the bus link and Sun SPARCstation, raw data acquisition and data server functions, application software conversion issues, and experiences with the UNIX operating system in the mixed platform environment
Development of the TFTR neutral beam injection system
International Nuclear Information System (INIS)
Prichard, B.A. Jr.
1977-01-01
The TFTR Neutral Beam Lines are designed to inject 20 MW of 120 keV neutral deuterium atoms into the plasma. This is accomplished using 12 sources, 65 amperes each, mounted in 4 beam lines. The 120 kV sources and a prototype beam line are being developed. The implementation of these beam lines has required the development of several associated pieces of hardware. 200 kV switch tubes for the power supplies are being developed for modulation and regulation of the accelerating supplies. A 90 cm metallic seal gate valve capable of sealing against atmosphere in either direction is being developed for separating the torus and beam line vacuum systems. A 70 x 80 cm fast shutter valve is also being developed to limit tritium migration from the torus into the beam line. Internal to the beam line a calorimeter, ion dump and deflection magnet have been designed to handle three beams, and optical diagnostics utilizing the doppler broadening and doppler shift of light emitted from the accelerated beam are being developed. The control and monitoring of the 12 sources will be done via the TFTR computer control system (CICADA) as will other parts of the machine, and software is being developed to condition and operate the sources automatically. The prototype beam line is scheduled to begin operation in the fall of 1978 and all four production beam lines on TFTR in 1982
Modified Mathematical Model For Neutralization System In Stirred Tank Reactor
Directory of Open Access Journals (Sweden)
Ahmmed Saadi Ibrehem
2011-05-01
Full Text Available A modified model for the neutralization process of Stirred Tank Reactors (CSTR reactor is presented in this study. The model accounts for the effect of strong acid [HCL] flowrate and strong base [NaOH] flowrate with the ionic concentrations of [Cl-] and [Na+] on the Ph of the system. In this work, the effect of important reactor parameters such as ionic concentrations and acid and base flowrates on the dynamic behavior of the CSTR is investigated and the behavior of mathematical model is compared with the reported models for the McAvoy model and Jutila model. Moreover, the results of the model are compared with the experimental data in terms of pH dynamic study. A good agreement is observed between our model prediction and the actual plant data. © 2011 BCREC UNDIP. All rights reserved(Received: 1st March 2011, Revised: 28th March 2011; Accepted: 7th April 2011[How to Cite: A.S. Ibrehem. (2011. Modified Mathematical Model For Neutralization System In Stirred Tank Reactor. Bulletin of Chemical Reaction Engineering & Catalysis, 6(1: 47-52. doi:10.9767/bcrec.6.1.825.47-52][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.825.47-52 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/825 ] | View in
Adam, Frédérick; Bertoncini, Fabrice; Brodusch, Nicolas; Durand, Emmanuelle; Thiébaut, Didier; Espinat, Didier; Hennion, Marie-Claire
2007-04-27
This paper reports an analytical method for the comprehensive two-dimensional gas chromatography (GC x GC) separation and identification of nitrogen compounds (N-compounds) in middle distillates according to their types (basicity). For the evaluation of the best chromatographic conditions, a non-polar x polar approach was chosen. The impact of the second dimension (stationary phase and column length) on the separation of basic and neutral N-compounds was evaluated by mean of two-dimensional resolution. This study revealed that the implementation of polar secondary column having free electron pairs improves drastically the separation of N-compounds. Indeed, the presence of permanent dipole-permanent dipole interactions between neutral N-compounds and the stationary phase was enlightened. The comparison of two different nitrogen chemiluminescence detectors (NCD) was also evaluated for GC x GC selective monitoring of N-compounds. Owing to higher resolution power and enhanced sensitivity achieved using developed chromatographic and detection conditions, it was possible to identify univocally and to quantitate N-compounds (i) by class of compounds and (ii), within a class, by carbon number. Finally, quantitative comparison of GC x GC-NCD with conventional gas chromatography illustrates the benefits of GC x GC leading to an excellent correlation with results obtained by American Society for Testing Materials (ASTM) methods for the determination of basic/neutral nitrogen ratio in diesel samples.
Neutral beam injection system design for KSTAR tokamak
Energy Technology Data Exchange (ETDEWEB)
Choi, B.H.; Lee, K.W.; Chung, K.S.; Oh, B.H.; Cho, Y.S.; Bae, Y.D.; Han, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea)
1998-06-01
The NBI system for KSTAR (Korean Superconducting Tokamak Advanced Research) has been designed based on conventional positive ion beam technology. One beam line consists of three ion sources, three neutralizers, one bending magnet, and one drift tube. This system will deliver 8 MW deuterium beam to KSTAR plasma in normal operation to support the advanced experiments on heating, current drive and profile control. The key technical issues in this design were high power ion source(120 kV, 65 A), long pulse operation (300 seconds; world record is 30 sec), and beam rotation from vertical to horizontal direction. The suggested important R and D points on ion source and beam line components are also included. (author). 7 refs., 27 figs., 1 tab.
Neutral sodium/bicarbonate/sulfate hot waters in geothermal systems
Energy Technology Data Exchange (ETDEWEB)
Mahon, W.A.J. (Dept. of Industrial and Scientific Research, Wairakei, New Zealand); Klyen, L.E.; Rhode, M.
1980-03-01
The least understood thermal water is a near neutral water which contains varying amounts of bicarbonate and sulfate as the major anions, low concentrations of chloride (< 30 ppM) and sodium as the major cation. In the past this water has been referred to as a sodium bicarbonate water but present studies suggest that the quantities of bicarbonate and sulfate in this water type are frequently of the same order. Of particular interest is the distribution and position of the sodium/bicarbonate/sulfate water in the same and different systems. Many hot springs in Indonesia, for example, discharge water of this composition. Present studies indicate that this water type can originate from high temperature reservoirs which form the secondary steam heated part of a normal high temperature geothermal system. The hydrological conditions producing these waters in geothermal systems are investigated and the relationship between the water type and vapor dominated systems is discussed. It is suggested that the major water type occurring in the so called vapor dominated parts of geothermal systems is this water. The water does not simply represent steam condensate, rather it consists essentially of meteoric water which has been steam heated. The water composition results from the interaction of carbon dioxide and hydrogen sulfide with meteoric water and the rocks confining this water in the aquifer.
Li, Bing; Li, Yongkun; Zhang, Xuemei
2016-01-01
In this paper, by using the existence of the exponential dichotomy of linear dynamic equations on time scales and the theory of calculus on time scales, we study the existence and global exponential stability of periodic solutions for a class of n-dimensional neutral dynamic equations on time scales. We also present an example to illustrate the feasibility of our results. The results of this paper are completely new and complementary to the previously known results even in both the case of differential equations (time scale [Formula: see text]) and the case of difference equations (time scale [Formula: see text]).
Factorizations of one-dimensional classical systems
International Nuclear Information System (INIS)
Kuru, Senguel; Negro, Javier
2008-01-01
A class of one-dimensional classical systems is characterized from an algebraic point of view. The Hamiltonians of these systems are factorized in terms of two functions that together with the Hamiltonian itself close a Poisson algebra. These two functions lead directly to two time-dependent integrals of motion from which the phase motions are derived algebraically. The systems so obtained constitute the classical analogues of the well known factorizable one-dimensional quantum mechanical systems
DIII-D Neutral Beam control system operator interface
International Nuclear Information System (INIS)
Harris, J.J.; Campbell, G.L.
1993-10-01
A centralized graphical user interface has been added to the DIII-D Neutral Beam (NB) control systems for status monitoring and remote control applications. This user interface provides for automatic data acquisition, alarm detection and supervisory control of the four NB programmable logic controllers (PLC) as well as the Mode Control PLC. These PLCs are used for interlocking, control and status of the NB vacuum pumping, gas delivery, and water cooling systems as well as beam mode status and control. The system allows for both a friendly user interface as well as a safe and convenient method of communicating with remote hardware that formerly required interns to access. In the future, to enable high level of control of PLC subsystems, complete procedures is written and executed at the touch of a screen control panel button. The system consists of an IBM compatible 486 computer running the FIX DMACS trademark for Windows trademark data acquisition and control interface software, a Texas Instruments/Siemens communication card and Phoenix Digital optical communications modules. Communication is achieved via the TIWAY (Texas Instruments protocol link utilizing both fiber optic communications and a copper local area network (LAN). Hardware and software capabilities will be reviewed. Data and alarm reporting, extended monitoring and control capabilities will also be discussed
Tokamak Fusion Test Reactor neutral beam injection system vacuum chamber
International Nuclear Information System (INIS)
Pedrotti, L.R.
1977-01-01
Most of the components of the Neutral Beam Lines of the Tokamak Fusion Test Reactor (TFTR) will be enclosed in a 50 cubic meter box-shaped vacuum chamber. The chamber will have a number of unorthodox features to accomodate both neutral beam and TFTR requirements. The design constraints, and the resulting chamber design, are presented
Performance of Doublet III neutral beam injector cryopumping system
International Nuclear Information System (INIS)
Langhorn, A.R.; Kim, J.; Tupper, M.L.; Williams, J.P.; Fasolo, J.
1984-01-01
The Doublet III neutral beam injector system is based on three beamlines; each beamline employs two 80 kV/80 A hydrogen ion sources. Two liquid helium (LHe) cooled cryopanel arrays were designed as an integral part of the beamline in order to provide high differential pumping of hydrogen gas along the beamline. The cryopanel arrays consist of a front (nearer to the torus) disk panel (3 m 2 each side) with liquid nitrogen (LN 2 ) cooled chevrons and a rear cylindrical panel of modified Santeler panels (8 m 2 ) which also employs LN 2 cooled surfaces shielding LHe cooled surfaces. These cryopanels are piped in series. The LHe delivery is based on a closed-loop, forced-flow scheme intended for variable panel temperatures (3.7 to 4.3 K). It uses small tubes for mechanical flexibility and thermal resiliency providing ease of economic defrosting. The cryogenic system consists of a liquefier (100 l/h), a large Dewar, a heat exchanger, and a liquid ring pump. Three beamlines are serviced simultaneously by the system. Pumping speeds measured locally at ionization gauges, were well in excess of the 1.4 x 10 6 l/s design goal
Lyapunov exponents for infinite dimensional dynamical systems
Mhuiris, Nessan Mac Giolla
1987-01-01
Classically it was held that solutions to deterministic partial differential equations (i.e., ones with smooth coefficients and boundary data) could become random only through one mechanism, namely by the activation of more and more of the infinite number of degrees of freedom that are available to such a system. It is only recently that researchers have come to suspect that many infinite dimensional nonlinear systems may in fact possess finite dimensional chaotic attractors. Lyapunov exponents provide a tool for probing the nature of these attractors. This paper examines how these exponents might be measured for infinite dimensional systems.
Physics of low-dimensional systems
International Nuclear Information System (INIS)
Anon.
1989-01-01
The physics of low-dimensional systems has developed in a remarkable way over the last decade and has accelerated over the last few years, in particular because of the discovery of the new high temperature superconductors. The new developments started more than fifteen years ago with the discovery of the unexpected quasi-one-dimensional character of the TTF-TCNQ. Since then the field of conducting quasi-one-dimensional organic system have been rapidly growing. Parallel to the experimental work there has been an important theoretical development of great conceptual importance, such as charge density waves, soliton-like excitations, fractional charges, new symmetry properties etc. A new field of fundamental importance was the discovery of the Quantum Hall Effect in 1980. This field is still expanding with new experimental and theoretical discoveries. In 1986, then, came the totally unexpected discovery of high temperature superconductivity which started an explosive development. The three areas just mentioned formed the main themes of the Symposium. They do not in any way exhaust the progress in low-dimensional physics. We should mention the recent important development with both two-dimensional and one-dimensional and even zero-dimensional structures (quantum dots). The physics of mesoscopic systems is another important area where the low dimensionality is a key feature. Because of the small format of this Symposium we could unfortunately not cover these areas
Study on three dimensional seismic isolation system
International Nuclear Information System (INIS)
Morishita, Masaki; Kitamura, Seiji
2003-01-01
Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Power Company (JAPC) launched joint research programs on structural design and three-dimensional seismic isolation technologies, as part of the supporting R and D activities for the feasibility studies on commercialized fast breeder reactor cycle systems. A research project by JAPC under the auspices of the Ministry of Economy, Trade, and Industry (METI) with technical support by JNC is included in this joint study. This report contains the results of the research on the three-dimensional seismic isolation technologies, and the results of this year's study are summarized in the following five aspects. (1) Study on Earthquake Condition for Developing 3-dimensional Base Isolation System. The case study S2 is one of the maximum ground motions, of which the records were investigated up to this time. But a few observed near the fault exceed the case study S2 in the long period domain, depending on the fault length and conditions. Generally it is appropriate that the response spectra ratio (vertical/horizontal) is 0.6. (2) Performance Requirement for 3-dimensional Base Isolation System and Devices. Although the integrity map of main equipment/piping dominate the design criteria for the 3-dimensional base isolation system, the combined integrity map is the same as those of FY 2000, which are under fv=1Hz and over hv=20%. (3) Developing Targets and Schedule for 3-dimensional Isolation Technology. The target items for 3-dimensional base isolation system were rearranged into a table, and developing items to be examined concerning the device were also adjusted. A development plan until FY 2009 was made from the viewpoint of realization and establishment of a design guideline on 3-dimensional base isolation system. (4) Study on 3-dimensional Entire Building Base Isolation System. Three ideas among six ideas that had been proposed in FY2001, i.e., '3-dimensional base isolation system incorporating hydraulic
Power supply system for KSTAR neutral beam injector
Energy Technology Data Exchange (ETDEWEB)
Cho, W., E-mail: franciscocho@nfri.re.kr; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.
2015-10-15
Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to
Power supply system for KSTAR neutral beam injector
International Nuclear Information System (INIS)
Cho, W.; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.
2015-01-01
Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to
Quantum Phenomena in Low-Dimensional Systems
Geller, Michael R.
2001-01-01
A brief summary of the physics of low-dimensional quantum systems is given. The material should be accessible to advanced physics undergraduate students. References to recent review articles and books are provided when possible.
Phase transitions in two-dimensional systems
International Nuclear Information System (INIS)
Salinas, S.R.A.
1983-01-01
Some experiences are related using synchrotron radiation beams, to characterize solid-liquid (fusion) and commensurate solid-uncommensurate solid transitions in two-dimensional systems. Some ideas involved in the modern theories of two-dimensional fusion are shortly exposed. The systems treated consist of noble gases (Kr,Ar,Xe) adsorbed in the basal plane of graphite and thin films formed by some liquid crystal shells. (L.C.) [pt
Radiation Safety System for SPIDER Neutral Beam Accelerator
International Nuclear Information System (INIS)
Sandri, S.; Poggi, C.; Coniglio, A.; D'Arienzo, M.
2011-01-01
SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma only) and MITICA (Megavolt ITER Injector Concept Advanced) are the ITER neutral beam injector (NBI) testing facilities of the PRIMA (Padova Research Injector Megavolt Accelerated) Center. Both injectors accelerate negative deuterium ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER with a maximum beam current of 40 A for both experiments. The SPIDER facility is classified in Italy as a particle accelerator. At present, the design of the radiation safety system for the facility has been completed and the relevant reports have been presented to the Italian regulatory authorities. Before SPIDER can operate, approval must be obtained from the Italian Regulatory Authority Board (IRAB) following a detailed licensing process. In the present work, the main project information and criteria for the SPIDER injector source are reported together with the analysis of hypothetical accidental situations and safety issues considerations. Neutron and photon nuclear analysis is presented, along with special shielding solutions designed to meet Italian regulatory dose limits. The contribution of activated corrosion products (ACP) to external exposure of workers has also been assessed. Nuclear analysis indicates that the photon contribution to worker external exposure is negligible, and the neutron dose can be considered by far the main radiation protection issue. Our results confirm that the injector has no important radiological impact on the population living around the facility.
Outgassing measurements and results used in designing the Doublet III Neutral Beam Injector System
International Nuclear Information System (INIS)
Yamamoto, R.M.; Harvey, J.
1979-11-01
Material vacuum properties played an important part in designing the Neutral Beam Injector System for General Atomic's Doublet III Tokamak. Low operating vacuum tank pressures were desired to keep re-ionization of the Neutral Beam to a minimum. Plasma contamination was also a major concern, hence stringent material impurity constraints were imposed. Outgassing Rate Measurement and Residual Gas Analyses were performed on different types of materials to determine if their vacuum properties were compatible with the Neutral Beam Injector System requirements
Initial operation and performance of the PDX neutral-beam injection system
International Nuclear Information System (INIS)
Kugel, H.W.; Eubank, H.P.; Kozub, T.A.; Rossmassler, J.E.; Schilling, G.; van Halle, A.; Williams, M.D.
1982-01-01
In 1981, the joint ORNL/PPPL PDX neutral beam heating project succeeded in reliably injecting 7.2 MW of D 0 into the PDX plasma, at nearly perpendicular angles, and achieved ion temperatures up to 6.5 keV. The expeditious achievement of this result was due to the thorough conditioning and qualification of the PDX neutral beam ion sources at ORNL prior to delivery coupled with several field design changes and improvements in the injection system made at PPPL as a result of neutral beam operating experience with the PLT tokamak. It has been found that the operation of high power neutral beam injection systems in a tokamak-neutral beam environment requires procedures and performance different from those required for development operation on test stands. In this paper, we review the installatin of the PDX neutral beam injection system, and its operation and performance during the initial high power plasma heating experiments with the PDX tokamak
Three-Dimensional Printing with Biomass-Derived PEF for Carbon-Neutral Manufacturing.
Kucherov, Fedor A; Gordeev, Evgeny G; Kashin, Alexey S; Ananikov, Valentine P
2017-12-11
Biomass-derived poly(ethylene-2,5-furandicarboxylate) (PEF) has been used for fused deposition modeling (FDM) 3D printing. A complete cycle from cellulose to the printed object has been performed. The printed PEF objects created in the present study show higher chemical resistance than objects printed with commonly available materials (acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), glycol-modified poly(ethylene terephthalate) (PETG)). The studied PEF polymer has shown key advantages for 3D printing: optimal adhesion, thermoplasticity, lack of delamination and low heat shrinkage. The high thermal stability of PEF and relatively low temperature that is necessary for extrusion are optimal for recycling printed objects and minimizing waste. Several successive cycles of 3D printing and recycling were successfully shown. The suggested approach for extending additive manufacturing to carbon-neutral materials opens a new direction in the field of sustainable development. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Considerations involved in the design of negative-ion-based neutral beam systems
International Nuclear Information System (INIS)
Cooper, W.S.
1983-11-01
We consider the requirements and constraints for negative-ion-based neutral beam injection systems, and show how these are reflected in design considerations. We will attempt to develop a set of guidelines for users and developers to use to see how well (in a qualitative sense, at least) a particular neutral beam system fits a particular proposed need
Status of CP and CPT violation in the neutral kaon system
Ruf, T
1996-01-01
A phenomenological description of the neutral-kaon system is presented without assuming \\CPT\\ conservation. The experimental methods and the underlying assumptions used to determine parameters of the neutral-kaon system (\\CP-violating and non \\CP-violating ones) are discussed. The experimental results are combined to test \\CPT\\ conservation with as little prejudice as possible.
Biofuels and climate neutrality - system analysis of production and utilisation
International Nuclear Information System (INIS)
Holmgren, Kristina; Eriksson, Erik; Olsson, Olle; Olsson, Mats; Hillring, Bengt; Parikka, Matti
2007-06-01
The objectives of this study were to investigate to what extent biofuels can be said to be climate neutral. An assessment of greenhouse gas emissions from the production and utilisation chains of a number of solid biofuels were made based on data available in the literature. The data has been used for making radiative forcing calculations. The study also includes a comparison between imported and domestic solid biofuels. We conclude that none of the investigated biofuel chains are 'climate neutral', since all of them result in net emissions of greenhouse gases. However, all of the chains result in lower emissions than corresponding emissions from the use of fossil fuels. The emission estimates for the fuel chains varies depending on fuels and on how system boundaries have been set in the different studies. The following factors can contribute significantly to the total emissions of greenhouse gases of the production and utilisation chain of a biofuel: impact of production system on soil carbon storage, land use methods (especially use of drained peatlands), the use of fertilisers (both direct and indirect), combustion technology, refining of the fuel (i.e. pelletisation) and storage (especially of comminuted fuels). Other sources that also contribute to the emissions during a production and utilisation chain are; harvesting machines, transportation and waste handling. The climate impacts of the greenhouse gas emissions from one of the biofuels, i.e. forest residues, were compared to the impacts of fossil fuels by the concept of radiative forcing. In the radiative forcing calculations the CO 2 emissions from combustion of biofuels and the CO 2 emissions that would have occurred if the residues had been left in the forest to decompose were included, and their different dynamics taken into consideration. The decomposition results in CO 2 emissions during a long time period and in an amount equalling those that are emitted during combustion. Only a minor part is due to
Two-dimensional quasi-neutral description of particles and fields above discrete auroral arcs
Newman, A. L.; Chiu, Y. T.; Cornwall, J. M.
1986-01-01
Models are presented for particle distributions, electric fields and currents in an adiabatic treatment of auroral electrostatic potential distributions in order to describe the quiet-time evening auroral arcs featuring both upward and return currents. The models are consistent with current continuity and charge balance requirements for particle populations controlled by adiabatic invariants and quasi-neutrality in the magnetosphere. The effective energy of the cool electron population is demonstrated to have a significant effect on the latitudinal breadth of the auroral electrostatic potential structure and the extent of the penetration of the accelerating potential into the ionosphere. Another finding is that the energy of any parallel potential drop in the lowest few thousand kilometers of the field line is of the same order of magnitude as the thermal energy of the cool electrons. Additional predictions include density cavities along field lines that support large potential drops, and density enhancements along field lines at the edge of an inverted V with a small potential drop.
Policies and initiatives for carbon neutrality in nordic heating and transport systems
DEFF Research Database (Denmark)
Muller, Jakob Glarbo; Wu, Qiuwei; Ostergaard, Jacob
2012-01-01
Policies and initiatives promoting carbon neutrality in the Nordic heating and transport systems are presented. The focus within heating systems is the propagation of heat pumps while the focus within transport systems is initiatives regarding electric vehicles (EVs). It is found that conversion...... to heat pumps in the Nordic region rely on both private economic and national economic incentives. Initiatives toward carbon neutrality in the transport system are mostly concentrated on research, development and demonstration for deployment of a large number of EVs. All Nordic countries have plans...... for the future heating and transport systems with the ambition of realizing carbon neutrality....
The discrete cones methods for two-dimensional neutral particle transport problems with voids
International Nuclear Information System (INIS)
Watanabe, Y.; Maynard, C.W.
1983-01-01
One of the most widely applied deterministic methods for time-independent, two-dimensional neutron transport calculations is the discrete ordinates method (DSN). The DSN solution, however, fails to be accurate in a void due to the ray effect. In order to circumvent this drawback, the authors have been developing a novel approximation: the discrete cones method (DCN), where a group of particles in a cone are simultaneously traced instead of particles in discrete directions for the DSN method. Programs, which apply to the DSN method in a non-vacuum region and the DCN method in a void, have been written for transport calculations in X-Y coordinates. The solutions for test problems demonstrate mitigation of the ray effect in voids without loosing the computational efficiency of the DSN method
International Nuclear Information System (INIS)
O'Dell, R.D.; Brinkley, F.W. Jr.; Marr, D.R.
1982-02-01
ONEDANT is designed for the CDC-7600, but the program has been implemented and run on the IBM-370/190 and CRAY-I computers. ONEDANT solves the one-dimensional multigroup transport equation in plane, cylindrical, spherical, and two-angle plane geometries. Both regular and adjoint, inhomogeneous and homogeneous (k/sub eff/ and eigenvalue search) problems subject to vacuum, reflective, periodic, white, albedo, or inhomogeneous boundary flux conditions are solved. General anisotropic scattering is allowed and anisotropic inhomogeneous sources are permitted. ONEDANT numerically solves the one-dimensional, multigroup form of the neutral-particle, steady-state form of the Boltzmann transport equation. The discrete-ordinates approximation is used for treating the angular variation of the particle distribution and the diamond-difference scheme is used for phase space discretization. Negative fluxes are eliminated by a local set-to-zero-and-correct algorithm. A standard inner (within-group) iteration, outer (energy-group-dependent source) iteration technique is used. Both inner and outer iterations are accelerated using the diffusion synthetic acceleration method
Simultaneous Hydrogen Generation and Waste Acid Neutralization in a Reverse Electrodialysis System
Hatzell, Marta C.; Zhu, Xiuping; Logan, Bruce E.
2014-01-01
power and hydrogen gas using waste heat-derived solutions, but high electrode overpotentials limit system performance. We show here that an ammonium bicarbonate (AmB) RED system can achieve simultaneous waste acid neutralization and in situ hydrogen
Joya, Khurram Saleem; Ahmad, Zahoor; Joya, Yasir Faheem; Garcia Esparza, Angel T.; de Groot, Huub
2016-01-01
In electrocatalytic water splitting systems pursuing for renewable energy using sun light, developing robust, stable and easy accessible materials operating under mild chemical conditions is pivotal. We present here unique nano-particulate type silver-oxide (AgOx-NP) based robust and highly stable electrocatalyst for efficient water oxidation. The AgOx-NP is generated in situ in a HCO3–/CO2 system under benign conditions. Mircographs show that they exhibit nanoscale box type squared nano-bipyramidal configuration. The oxygen generation is initiated at low overpotential, and a sustained O2 evolution current density of > 1.1 mA cm–2 is achieved during prolonged-period water electrolysis. The AgOx-NP electrocatalyst performs exceptionally well in metal-ions free neutral or near-neutral carbonate, phosphate and borate buffers relative to recently reported Co-oxide and Ni-oxide based heterogeneous electrocatalysts, which are unstable in metal-ions free electrolyte and tend to degrade with time and lose catalytic performance during long-term experimental tests.
Joya, Khurram Saleem
2016-07-19
In electrocatalytic water splitting systems pursuing for renewable energy using sun light, developing robust, stable and easy accessible materials operating under mild chemical conditions is pivotal. We present here unique nano-particulate type silver-oxide (AgOx-NP) based robust and highly stable electrocatalyst for efficient water oxidation. The AgOx-NP is generated in situ in a HCO3–/CO2 system under benign conditions. Mircographs show that they exhibit nanoscale box type squared nano-bipyramidal configuration. The oxygen generation is initiated at low overpotential, and a sustained O2 evolution current density of > 1.1 mA cm–2 is achieved during prolonged-period water electrolysis. The AgOx-NP electrocatalyst performs exceptionally well in metal-ions free neutral or near-neutral carbonate, phosphate and borate buffers relative to recently reported Co-oxide and Ni-oxide based heterogeneous electrocatalysts, which are unstable in metal-ions free electrolyte and tend to degrade with time and lose catalytic performance during long-term experimental tests.
Three dimensional electrochemical system for neurobiological studies
DEFF Research Database (Denmark)
Vazquez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith
2009-01-01
In this work we report a novel three dimensional electrode array for electrochemical measurements in neuronal studies. The main advantage of working with these out-of-plane structures is the enhanced sensitivity of the system in terms of measuring electrochemical changes in the environment...
Observation of CP Violation in the Neutral B Meson System
Energy Technology Data Exchange (ETDEWEB)
Levy, S
2004-06-16
This dissertation presents a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of about 88 million {Upsilon}(4S) {yields} B{bar B} decays collected between 1999 and 2002. We study events in which one neutral B meson decay to the CP-eigenstates J/{psi} K{sub S}{sup 0}, {psi}(2S)K{sub S}{sup 0}, {chi}{sub c1}K{sub S}{sup 0}, and {eta}{sub c}K{sub S}{sup 0}, or to flavor-eigenstates involving D{sup (*)}{pi}/{rho}/a{sub 1} and J/{psi}K*{sup 0}(K*{sup 0} {yields} K{sup +} {pi}{sup -}), is fully reconstructed. The flavor of the other neutral B meson is tagged at the time of its decay, mainly using the charge of identified leptons and kaons. The proper time elapsed between the meson decays is determined by measuring the distance between the decay vertices. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2{beta}, is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor- and CP-eigenstate samples. We measure sin2{beta} = 0.755 {+-} 0.074 (stat) {+-} 0.030 (syst).
Plasma and neutral gas jet interactions in the exhaust of a magnetic confinement system
International Nuclear Information System (INIS)
Krueger, W.A.
1990-06-01
A general purpose 2-1/2 dimensional, multifluid, time dependent computer code has been developed. This flexible tool models the dynamic behavior of plasma/neutral gas interactions in the presence of a magnetic field. The simulation has been used to examine the formation of smoke ring structure in the plasma rocket exhaust by injection of an axial jet of neutral gas. Specifically, the code was applied to the special case of attempting to couple the neutral gas momentum to the plasma in such a manner that plasma smoke rings would form, disconnecting the plasma from the magnetic field. For this scenario several cases where run scanning a wide range of neutral gas input parameters. In all the cases it was found that after an initial transient phase, the plasma eroded the neutral gas and after that followed the original magnetic field. From these findings it is concluded that smoke rings do not form with axial injection of neutral gas. Several suggestions for alternative injection schemes are presented
Observational Aspects of Symmetries of the Neutral B Meson System
Fidecaro, Maria; Ruf, Thomas
2015-01-01
We revisit various results, which have been obtained by the BABAR and Belle Collaborations over the last twelve years, concerning symmetry properties of the Hamiltonian, which governs the time evolution and the decay of neutral B mesons. We find that those measurements, which established CP violation in B meson decay, 13 years ago, had as well established T (time-reversal) symmetry violation. They also confirmed CPT symmetry in the decay (T$_{CPT}$ = 0) and symmetry with respect to time-reversal ( $\\epsilon$ = 0) and to CPT ($\\delta$ = 0) in the $B^0 \\bar{B}^0$ oscillation.
Modeling and experimental studies of the DIII-D neutral beam system
Energy Technology Data Exchange (ETDEWEB)
Crowley, B., E-mail: crowleyb@fusion.gat.com; Rauch, J.; Scoville, J.T.
2015-10-15
Highlights: • The issues surrounding proposals to increase neutral beam power are evaluated. • A tetrode version of the DIII-D ion source is modeled. • A neutralization efficiency of the DIII-D neutral beam is measured. • A power loading model of the neutral beam line is presented. - Abstract: In this paper, we present the results of beam physics experimental and modeling efforts aimed at learning from and building on the experience of the DIII-D off-axis neutral beam upgrade and other neutral beam system upgrades such as those at JET. The modeling effort includes electrostatic accelerator modeling (using a Poisson solver), gas dynamics modeling for the neutralizer and beam transport models for the beamline. Experimentally, spectroscopic and calorimetric techniques are used to evaluate the system performance. We seek to understand and ameliorate problems such as anomalous power deposition, originating from misdirected or excessively divergent beam particles, on a number of beamline components. We qualitatively and quantitatively evaluate possible project risks such as neutralization efficiency deficit and high voltage hold off associated with increasing the beam energy up to 105 keV.
Computer-controlled data acquisition system for the ISX-B neutral injection system
International Nuclear Information System (INIS)
Edmonds, P.H.; Sherrill, B.; Pearce, J.W.
1980-05-01
A data acquisition system for the Impurity Study Experiment (ISX-B) neutral injection system at the Oak Ridge National Laboratory is presented. The system is based on CAMAC standards and is controlled by a MIK-11/2 microcomputer. The system operates at the ion source high voltage on the source table, transmitting the analyzed data to a terminal at ground potential. This reduces the complexity of the communications link and also allows much flexibility in the diagnostics and eventual control of the beam line
Sustaining neutral beam power supply system for the Mirror Fusion Test Facility
International Nuclear Information System (INIS)
Eckard, R.D.; Van Ness, H.W.
1979-01-01
A fixed-price procurement contract for $24.9 million was awarded to Aydin Energy Division, Palo Alto, CA, for the design, manufacture, installation, and acceptance testing of the sustaining neutral beam power supply system (SNBPSS). This system is scheduled for completion in early 1981 and will provide the conditioned power for the 24 neutral beam source modules. Each of the 24 power supply sets will provide the accel potential of 80 kV at 88 A, the arc power, the filament power, and the suppressor power for its associated neutral beam source module
Energy Technology Data Exchange (ETDEWEB)
Nicolaescu, Dan, E-mail: Dan.Nicolaescu@kt2.ecs.kyoto-u.ac.jp [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Sakai, Shigeki [Nissin Ion Equipment Co., Ltd., 575 Kuze Tonoshiro-cho, Minami-ku, Kyoto 601-8205 (Japan); Gotoh, Yasuhito [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Ishikawa, Junzo [Department of Electronics and Information Engineering, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501 (Japan)
2011-07-21
Advanced implantation systems used for semiconductor processing require transportation of quasi-parallel ion beams, which have low energy ({sup 11}B{sup +}, {sup 31}P{sup +},{sup 75}As{sup +}, E{sub ion}=200-1000 eV). Divergence of the ion beam due to space charge effects can be compensated through injection of electrons into different regions of the ion beam. The present study shows that electron confinement takes place in regions of strong magnetic field such as collimator magnet provided with surface mirror magnetic fields and that divergence of the ion beam passing through such regions is largely reduced. Modeling results have been obtained using Opera3D/Tosca/Scala. Electrons may be provided by collision between ions and residual gas molecules or may be injected by field emitter arrays. The size of surface magnets is chosen such as not to disturb ion beam collimation, making the approach compatible with ion beam systems. Surface magnets may form thin magnetic layers with thickness h=0.5 mm or less. Conditions for spacing of surface magnet arrays for optimal electron confinement are outlined.
Ion-neutral transport through quadrupole interfaces of mass-spectrometer systems
International Nuclear Information System (INIS)
Jugroot, M.; Groth, C.P.T.; Thomson, B.A.; Baranov, V.; Collings, B.A.; French, J.B.
2004-01-01
The transport of free ions through highly under-expanded jet flows of neutral gases and in the presence of applied electric fields is investigated by continuum-based numerical simulations. In particular, numerical results are described which are relevant to ion flows occurring in quadrupole interfaces of mass spectrometer systems. A five-moment mathematical model and parallel multi-block numerical solution procedure is developed for predicting the ion transport. The model incorporates the effects of ion-neutral collision processes and is used in conjunction with a Navier-Stokes model and flow solver for the neutral gas to examine the key influences controlling the ion motion. The effects of the neutral gas flow, electric fields (both dc and rf), and flow field geometry on ion mobility are carefully assessed. The capability of controlling the charged particle motions through a combination of directed neutral flow and applied electric field is demonstrated for these high-speed, hypersonic, jet flows. (author)
Edge plasma diagnostics in the compact helical system (CHS) device using fast neutral lithium beam
Energy Technology Data Exchange (ETDEWEB)
Ueda, Mario
1992-05-01
This paper reports the research activities of the author on using fast neutral lithium beam edge plasma diagnostic, at the Japanese National Institute for Fusion Science compact helical system (CHS). (author). 20 figs.
Conceptual design of a neutral-beam injection system for the TFTR
International Nuclear Information System (INIS)
Ehlers, K.W.; Berkner, K.H.; Cooper, W.S.; Hooper, E.B.; Pyle, R.V.; Stearns, J.W.
1975-11-01
The neutral-beam injection requirements for heating and fueling the next generation of fusion reactor experiments far exceed those of present devices; the neutral-beam systems needed to meet these requirements will be large and complex. A conceptual design of a TFTR tokamak injection system to produce 120 keV deuterium-ion beams with a total power of about 80 MW is given
DANTSYS: A diffusion accelerated neutral particle transport code system
International Nuclear Information System (INIS)
Alcouffe, R.E.; Baker, R.S.; Brinkley, F.W.; Marr, D.R.; O'Dell, R.D.; Walters, W.F.
1995-06-01
The DANTSYS code package includes the following transport codes: ONEDANT, TWODANT, TWODANT/GQ, TWOHEX, and THREEDANT. The DANTSYS code package is a modular computer program package designed to solve the time-independent, multigroup discrete ordinates form of the boltzmann transport equation in several different geometries. The modular construction of the package separates the input processing, the transport equation solving, and the post processing (or edit) functions into distinct code modules: the Input Module, one or more Solver Modules, and the Edit Module, respectively. The Input and Edit Modules are very general in nature and are common to all the Solver Modules. The ONEDANT Solver Module contains a one-dimensional (slab, cylinder, and sphere), time-independent transport equation solver using the standard diamond-differencing method for space/angle discretization. Also included in the package are solver Modules named TWODANT, TWODANT/GQ, THREEDANT, and TWOHEX. The TWODANT Solver Module solves the time-independent two-dimensional transport equation using the diamond-differencing method for space/angle discretization. The authors have also introduced an adaptive weighted diamond differencing (AWDD) method for the spatial and angular discretization into TWODANT as an option. The TWOHEX Solver Module solves the time-independent two-dimensional transport equation on an equilateral triangle spatial mesh. The THREEDANT Solver Module solves the time independent, three-dimensional transport equation for XYZ and RZΘ symmetries using both diamond differencing with set-to-zero fixup and the AWDD method. The TWODANT/GQ Solver Module solves the 2-D transport equation in XY and RZ symmetries using a spatial mesh of arbitrary quadrilaterals. The spatial differencing method is based upon the diamond differencing method with set-to-zero fixup with changes to accommodate the generalized spatial meshing
DANTSYS: A diffusion accelerated neutral particle transport code system
Energy Technology Data Exchange (ETDEWEB)
Alcouffe, R.E.; Baker, R.S.; Brinkley, F.W.; Marr, D.R.; O`Dell, R.D.; Walters, W.F.
1995-06-01
The DANTSYS code package includes the following transport codes: ONEDANT, TWODANT, TWODANT/GQ, TWOHEX, and THREEDANT. The DANTSYS code package is a modular computer program package designed to solve the time-independent, multigroup discrete ordinates form of the boltzmann transport equation in several different geometries. The modular construction of the package separates the input processing, the transport equation solving, and the post processing (or edit) functions into distinct code modules: the Input Module, one or more Solver Modules, and the Edit Module, respectively. The Input and Edit Modules are very general in nature and are common to all the Solver Modules. The ONEDANT Solver Module contains a one-dimensional (slab, cylinder, and sphere), time-independent transport equation solver using the standard diamond-differencing method for space/angle discretization. Also included in the package are solver Modules named TWODANT, TWODANT/GQ, THREEDANT, and TWOHEX. The TWODANT Solver Module solves the time-independent two-dimensional transport equation using the diamond-differencing method for space/angle discretization. The authors have also introduced an adaptive weighted diamond differencing (AWDD) method for the spatial and angular discretization into TWODANT as an option. The TWOHEX Solver Module solves the time-independent two-dimensional transport equation on an equilateral triangle spatial mesh. The THREEDANT Solver Module solves the time independent, three-dimensional transport equation for XYZ and RZ{Theta} symmetries using both diamond differencing with set-to-zero fixup and the AWDD method. The TWODANT/GQ Solver Module solves the 2-D transport equation in XY and RZ symmetries using a spatial mesh of arbitrary quadrilaterals. The spatial differencing method is based upon the diamond differencing method with set-to-zero fixup with changes to accommodate the generalized spatial meshing.
Shielding considerations for neutral-beam injection systems
International Nuclear Information System (INIS)
de Seynes, X.
1983-03-01
Results of a study on the geometry of an FED-A Neutral Beam Injector beamline duct shield are presented. Also included is a calculation of dose rates, as a function of time, from an activated NBI. The shielding investigations consisted of varying the parameters of the geometry and transporting particles through it using the MCNP Monte-Carlo code. The dose rates were calculated by the ACDOS3 code using realistic MCNP results. A final-to-incident flux ratio of 6.5 x 10 -7 can be achieved through the use of a 65.5 cm reentry duct. This is for a realistic source and pure water shielding material. The activated NBI produced a dose rate of 15.9 mrem/hr two and a half days after shutdown of the reactor
Tian, Di; Winter, Stephen M; Mailman, Aaron; Wong, Joanne W L; Yong, Wenjun; Yamaguchi, Hiroshi; Jia, Yating; Tse, John S; Desgreniers, Serge; Secco, Richard A; Julian, Stephen R; Jin, Changqing; Mito, Masaki; Ohishi, Yasuo; Oakley, Richard T
2015-11-11
Pressure-induced changes in the solid-state structures and transport properties of three oxobenzene-bridged bisdithiazolyl radicals 2 (R = H, F, Ph) over the range 0-15 GPa are described. All three materials experience compression of their π-stacked architecture, be it (i) 1D ABABAB π-stack (R = Ph), (ii) quasi-1D slipped π-stack (R = H), or (iii) 2D brick-wall π-stack (R = F). While R = H undergoes two structural phase transitions, neither of R = F, Ph display any phase change. All three radicals order as spin-canted antiferromagnets, but spin-canted ordering is lost at pressures pressure, and the thermal activation energy for conduction Eact is eliminated at pressures ranging from ∼3 GPa for R = F to ∼12 GPa for R = Ph, heralding formation of a highly correlated (or bad) metallic state. For R = F, H the pressure-induced Mott insulator to metal conversion has been tracked by measurements of optical conductivity at ambient temperature and electrical resistivity at low temperature. For R = F compression to 6.2 GPa leads to a quasiquadratic temperature dependence of the resistivity over the range 5-300 K, consistent with formation of a 2D Fermi liquid state. DFT band structure calculations suggest that the ease of metallization of these radicals can be ascribed to their multiorbital character. Mixing and overlap of SOMO- and LUMO-based bands affords an increased kinetic energy stabilization of the metallic state relative to a single SOMO-based band system.
Design of cryo-vacuum system for MW neutral beam injector
International Nuclear Information System (INIS)
Hu Chundong; Xie Yuanlai
2010-01-01
Neutral beam injector is an equipment that is used to produce and then to neutralize high energetic particle beam. A neutral beam injector (EAST-NBI) with MW magnitude neutral beam power is considered to be developed to support the EAST physical research. The requirements for vacuum system were analyzed after introducing the principle of EAST-NBI. A differential vacuum system structure was chosen after analyzing the performance of different vacuum pumping system structure. The gas sources and their characteristics were analyzed, and two inserted type cryocondensation pumps were chosen as main vacuum pump. The schematic structure of the two cryocondensation pump with pumping area 8 m 2 and 6 m 2 were given and their cooling method and temperature control mode were determined. (authors)
International Nuclear Information System (INIS)
Purgalis, P.; Anderson, O.A.; Cooper, W.S.; DeVries, G.E.; Lietzke, A.F.; Kunkel, W.B.; Kwan, J.W.; Matuk, C.A.; Nakai, T.; Stearns, J.W.; Soroka, L.; Wells, R.P.; Lindquist, W.B.; Neef, W.S.; Reginato, L.L.; Sedgley, D.W.; Brook, J.W.; Luzzi, T.E.; Myers, T.J.
1989-01-01
Design of a neutral beamline for ITER (International Thermonuclear Experimental Reactor) is described. The design incorporates a barium surface conversion D - source feeding a linear array of accelerator channels. The system uses a dc accelerator with electrostatic quadrupoles for strong focusing. A high voltage power supply that is integrated with the accelerator is presented as an attractive option. A gas neutralizer is used and residual ions exiting the neutralizer are deflected to watercooled dumps. Cryopanels are located at the accelerator exit to pump excess gas from the source and the neutralizer, and in the ion dump cavity to pump re-neutralized ions and neutralizer gas. All the above components are packaged in compact identical, independent modules that can be removed for remote maintenance. The neutral beam system delivers 75 MW of D degree into three ports with a total of nine modules arranged in stacks of three modules per port. To increase reliability each module is designed to deliver up to 10 MW at 1.3 MeV; this allows eight modules operating at partial capacity to deliver the required power in the event one module is removed from service. Radiation protection is provided by shielding and by locating critical components in the source and accelerator 35 m from the port into the torus. Neutron shielding in the drift duct provides the added feature of limiting conductance and thus reducing gas flow to and from the torus. Alternative component choices are also discussed for the evolving design. 8 refs., 4 figs., 1 tab
International Nuclear Information System (INIS)
Bakke, K.; Furtado, C.
2012-01-01
We study the quantum dynamics of a neutral particle in the Aharonov-Casher system and in the Landau-Aharonov-Casher system confined to a two-dimensional quantum ring, a quantum dot, and a quantum anti-dot potentials described by the Tan-Inkson model [W.-C. Tan and J. C. Inkson, Semicond. Sci. Technol. 11, 1635 (1996)]. We show, in the Aharonov-Casher system, that bound states can be achieved when the neutral particle is confined to the two-dimensional quantum ring and the quantum dot and discuss the appearance of persistent currents. In the Landau-Aharonov-Casher system, we show that bound states can be achieved when the neutral particle is confined to the quantum anti-dot, quantum dot, and the two-dimensional quantum ring, but there are no persistent currents.
Two-dimensional topological photonic systems
Sun, Xiao-Chen; He, Cheng; Liu, Xiao-Ping; Lu, Ming-Hui; Zhu, Shi-Ning; Chen, Yan-Feng
2017-09-01
The topological phase of matter, originally proposed and first demonstrated in fermionic electronic systems, has drawn considerable research attention in the past decades due to its robust transport of edge states and its potential with respect to future quantum information, communication, and computation. Recently, searching for such a unique material phase in bosonic systems has become a hot research topic worldwide. So far, many bosonic topological models and methods for realizing them have been discovered in photonic systems, acoustic systems, mechanical systems, etc. These discoveries have certainly yielded vast opportunities in designing material phases and related properties in the topological domain. In this review, we first focus on some of the representative photonic topological models and employ the underlying Dirac model to analyze the edge states and geometric phase. On the basis of these models, three common types of two-dimensional topological photonic systems are discussed: 1) photonic quantum Hall effect with broken time-reversal symmetry; 2) photonic topological insulator and the associated pseudo-time-reversal symmetry-protected mechanism; 3) time/space periodically modulated photonic Floquet topological insulator. Finally, we provide a summary and extension of this emerging field, including a brief introduction to the Weyl point in three-dimensional systems.
Lawrence Berkeley laboratory neutral-beam engineering test facility power-supply system
International Nuclear Information System (INIS)
Lutz, I.C.; Arthur, C.A.; deVries, G.J.; Owren, H.M.
1981-10-01
The Lawrence Berkeley Laboratory is upgrading the neutral beam source test facility (NBSTF) into a neutral beam engineering test facility (NBETF) with increased capabilities for the development of neutral beam systems. The NBETF will have an accel power supply capable of 170 kV, 70 A, 30 sec pulse length, 10% duty cycle; and the auxiliary power supplies required for the sources. This paper describes the major components, their ratings and capabilities, and the flexibility designed to accomodate the needs of source development
71: Three dimensional radiation treatment planning system
International Nuclear Information System (INIS)
Purdy, J.A.; Wong, J.W.; Harms, W.B.; Drzymala, R.E.; Emami, B.
1987-01-01
A prototype 3-dimensional (3-D) radiation treatment planning (RTP) system has been developed and is in use. The system features a real-time display device and an array processor for computer intensive computations. The dose distribution can be displayed as 2-D isodose distributions superimposed on 2-D gray scale images of the patient's anatomy for any arbitrary plane and as a display of isodose surfaces in 3-D. In addition, dose-volume histograms can be generated. 7 refs.; 2 figs
International Nuclear Information System (INIS)
White, R.C.
1988-01-01
A prototype energy conversion system is presently in operation at Cadarache, France. Such a device is planned for installation on each six neutral beam injectors for use in the Tore Supra experiment in 1989. We present calculations of beam performance that may influence design considerations. The calculations are performed with the DART charged particle beam code. We investigate the effects of cold plasma, direct energy conversion and neutral beam production. 4 refs., 6 figs., 4 tabs
Power supply system on HT-7 tokamak for diagnostic neutral beam based on PLC
International Nuclear Information System (INIS)
Zhang Jian; Liu Baohua; Ding Tonghai; Du Shaowu
2006-01-01
A power supply system for diagnostic neutral beam on the HT-7 Tokamak was developed. Its logic control system based on S7-300 PLC was described. The experimental results show that the system is easy to operate and its performance is reliable. (authors)
One-dimensional autonomous systems and dissipative systems
International Nuclear Information System (INIS)
Lopez, G.
1996-01-01
The Lagrangian and the Generalized Linear Momentum are given in terms of a constant of motion for a one-dimensional autonomous system. The possibility of having an explicit Hamiltonian expression is also analyzed. The approach is applied to some dissipative systems. Copyright copyright 1996 Academic Press, Inc
Alternatives for blocking direct current in AC system neutrals at the Radisson/LG2 complex
International Nuclear Information System (INIS)
Eitzmann, M.A.; Walling, R.A.; Sublich, M.; Kah, A.; Huynh, H.; Granger, M.; Dutil, A.
1992-01-01
Severe offset saturation results from the passage of direct current through power transformers. Such direct current can arise from geomagnetic disturbances, or resistive coupling of the substation ground to HVDC earth electrodes. This paper documents the development of alternative approaches for the design and application of blocking devices placed between transformer neutrals and the substation ground. System constraints on the impedance and overvoltage limitation of the neutral blocking device (NBD) are covered. Three alternative NBD schemes are developed and optimized. System performance of the NBD is discussed, as are the practical implementation considerations for this unconventional equipment application. Although the paper focuses on the NBD requirements of Hydro-Quebec's Radisson/LG2 complex, the fundamental information is applicable to any situation where dc must be clocked from a power transformer neutral in a system designed for effectively-grounded operation
Evolution of a neutral-ion 2 fluid system using thermal lattice Boltzmann model
International Nuclear Information System (INIS)
Vahala, L.; Vahala, G.; Carter, J.; Pavlo, P.
2000-01-01
The 2D evolution of a 2-species system is examined using the thermal lattice Boltzmann model (TLBM). The effects of velocity shear layers on sharp heat fronts are considered for a neutral-ion system in the case where both species are turbulent. The rate at which the species velocities and temperatures equilibrate no longer follow the Morse estimate. (author)
International Nuclear Information System (INIS)
Hamilton, G.W.
1977-01-01
The practical effects of blistering and flaking in neutral injection systems are studied. These effects will soon be more important because of energy increases in systems now under development and because of their operation with fast helium ions as well as hydrogen and deuterium ions. Two main effects were studied: enhanced erosion rate and possible voltage breakdown from sharp flakes and gas emission
Three-dimensional hologram display system
Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)
2009-01-01
The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.
Remote handling concept for the neutral beam system
International Nuclear Information System (INIS)
Choi, Chang-Hwan; Palmer, Jim; Conesa, Carles; Friconneau, Jean-Pierre; Martins, Jean-Pierre; Subramanian, Rajendran; Jeannoutot, Thomas; Graceffa, Joseph; Schunke, Beatrix; Uffelen, MarcoVan; Damiani, Carlo; Tesini, Alessandro
2011-01-01
The NB ITER Remote Maintenance System (NB IRMS) provides the means for the remote maintenance within the NB Cell by removal and replacement of the plant equipment. The NB IRMS will be installed and removed with the assistance of human workers during the preparation, and post-operation phase. During the maintenance operation after opening the Passive Magnetic Shield (PMS) and vessels, the maintenance activity and recovery from failure should be conducted remotely. This paper describes the concept design of the NB IRMS operating inside the NB cell for maintenance of the plant equipment such as NB components, and Upper Port Plugs (UPP). The main tasks of the IRMS, the description of the sub-systems and their specification, and deployment/operation principles are presented. The transportation concept of the NB IRMS to the hot cell facility for storage and maintenance is presented, which is to avoid unnecessary exposure on the equipment inside the NB cell during the machine operation.
PLT and Doublet III neutral beam injection systems
International Nuclear Information System (INIS)
Haselton, H.H.; Dagenhart, W.K.; Schechter, D.E.; Stewart, L.D.; Stirling, W.L.
1976-01-01
The design program is being supported by experimental work with all beam line components: gas cells, bending magnets, beam stops, magnetic shielding, and high speed-high throughput cryopumping systems. Stray toroidal fields and fields produced by external transmission or mirror magnets are under study to determine the optimum means of removing the unneutralized component from the beam. Concepts utilizing materials with high permeability are adequate to provide the source with the necessary magnetic shielding. Beam stops capable of dissipating a power density of 10 to 40 kW/cm 2 are required for ion dumps, diagnostics, and on line ion source conditioning
Some problems of dynamical systems on three dimensional manifolds
International Nuclear Information System (INIS)
Dong Zhenxie.
1985-08-01
It is important to study the dynamical systems on 3-dimensional manifolds, its importance is showing up in its close relation with our life. Because of the complication of topological structure of Dynamical systems on 3-dimensional manifolds, generally speaking, the search for 3-dynamical systems is not easier than 2-dynamical systems. This paper is a summary of the partial result of dynamical systems on 3-dimensional manifolds. (author)
Electrical control of truly two-dimensional neutral and charged excitons in monolayer MoSe2
Ross, Jason; Wu, Sanfeng; Yu, Hongyi; Ghimire, Nirmal; Jones, Aaron; Aivazian, Grant; Yan, Jiaqiang; Mandrus, David; Xiao, Di; Xiao, Di; Xu, Xiaodong
2013-03-01
Monolayer transition metal dichalcogenides (TMDs) have emerged as ideal 2D semiconductors with valley and spin polarized excitations expected to enable true valley-tronics. Here we investigate MoSe2, a TMD which has yet to be characterized in the monolayer limit. Specifically, we examine excitons and trions (their singly charged counterparts) in the ultimate 2D limit. Utilizing high quality exfoliated MoSe2 monolayers, we report the observation and electrostatic tunability of positively charged (X +) , neutral (Xo), and negatively charged (X-) excitons via photoluminescence in FETs. The trion charging energy is large (30 meV), enhanced by strong confinement and heavy effective masses, while the linewidth is narrow (5 meV) at temperatures below 55 K. This is greater spectral contrast than in any known quasi-2D system. Further, the charging energies for X + and X- to are nearly identical implying the same effective mass for electrons and holes, which supports their recent description as massive Dirac fermions. This work demonstrates that monolayer MoSe2 is an ultimate 2D semiconductor opening the door for the investigation of truly 2D exciton physics while laying the ground work necessary to begin valley-spin polarization studies. Support: US DoE, BES, Division of MSE. HY and WY supported by Research Grant Council of Hong Kong
Measurements of Discrete Symmetries in the Neutral Kaon System with the CPLEAR (PS195) Experiment
Ruf, Thomas
2015-01-01
The antiproton storage ring LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of T, CPT and CP symmetries in the neutral kaon system. It measured with high precision the time evolution of initially strangeness-tagged $K^0$ and $\\bar{K}^0$ states to determine the size of violations with respect to these symmetries in the context of a systematic study. In parallel, limits concerning quantum-mechanical predictions (EPR paradox, coherence of the wave function) or the equivalence principle of general relativity have been obtained. This article will first discuss briefly the unique low energy antiproton storage ring LEAR followed by a description of the CPLEAR experiment, including the basic formalism necessary to understand the time evolution of a neutral kaon state and the main results related to measurements of discrete symmetries in the neutral kaon system. An exce...
Sustaining neutral beam power supply system for the Mirror Fusion Test Facility
International Nuclear Information System (INIS)
Eckard, R.D.; Wilson, J.H.; Van Ness, H.W.
1980-01-01
In late August 1978, a fixed price procurement contract for $25,000,000 was awarded to Aydin Energy Division, Palo Alto, California, for the design, manufacture, installation and acceptance testing of the Lawrence Livermore National Laboratory Mirror Fusion Test Facility (MFTF) Sustaining Neutral Beam Power Supply System (SNBPSS). This system of 24 power supply sets will provide the conditioned power for the 24 neutral beam source modules. Each set will provide the accel potential the arc power, the filament power, and the suppressor power for its associated neutral beam source module. The design and development of the SNBPSS has progressed through the final design phase and is now in production. Testing of the major sub-assembly power supply is proceeding at Aydin and the final acceptance testing of the first two power supplies at LLNL is expected to be completed this year
Bifurcation analysis of a three dimensional system
Directory of Open Access Journals (Sweden)
Yongwen WANG
2018-04-01
Full Text Available In order to enrich the stability and bifurcation theory of the three dimensional chaotic systems, taking a quadratic truncate unfolding system with the triple singularity equilibrium as the research subject, the existence of the equilibrium, the stability and the bifurcation of the system near the equilibrium under different parametric conditions are studied. Using the method of mathematical analysis, the existence of the real roots of the corresponding characteristic equation under the different parametric conditions is analyzed, and the local manifolds of the equilibrium are gotten, then the possible bifurcations are guessed. The parametric conditions under which the equilibrium is saddle-focus are analyzed carefully by the Cardan formula. Moreover, the conditions of codimension-one Hopf bifucation and the prerequisites of the supercritical and subcritical Hopf bifurcation are found by computation. The results show that the system has abundant stability and bifurcation, and can also supply theorical support for the proof of the existence of the homoclinic or heteroclinic loop connecting saddle-focus and the Silnikov's chaos. This method can be extended to study the other higher nonlinear systems.
Instrumentation and control of the Doublet III Neutral Beam Injector System
Energy Technology Data Exchange (ETDEWEB)
Kohli, J.C.; Moore, C.D.; Drobnis, D.D.; Elischer, V.P.; Kilgore, R.; Uber, D.
1980-03-01
The hardware and software required for the operation of the Doublet III Neutral Beam Injector System (NBIS) are described. Development and implementation of this Instrumentation and Control System was divided between the major participants - General Atomic Company and Lawrence Berkeley Laboratory. The subdivision of responsibilities and the coordination of the participants' activities are described with reference to hardware and software requirements in support of the entire system. Included are a description of the operators' consoles, the interlock system and the CAMAC system. One feature of the control software is source modeling. This feature includes feedback on a shot to shot basis and adaptive control. Adaptive control permits the computer system to automatically adjust parameters after a shot, and to control the system to automatically compensate for time varying NBIS components. The Neutral Beam Power Supply features power supply modeling, fiber optic transmission of analog signals and digital control of power supply power-up/interlocks.
Instrumentation and control of the Doublet III Neutral Beam Injector System
International Nuclear Information System (INIS)
Kohli, J.C.; Moore, C.D.; Drobnis, D.D.; Elischer, V.P.; Kilgore, R.; Uber, D.
1980-03-01
The hardware and software required for the operation of the Doublet III Neutral Beam Injector System (NBIS) are described. Development and implementation of this Instrumentation and Control System was divided between the major participants - General Atomic Company and Lawrence Berkeley Laboratory. The subdivision of responsibilities and the coordination of the participants' activities are described with reference to hardware and software requirements in support of the entire system. Included are a description of the operators' consoles, the interlock system and the CAMAC system. One feature of the control software is source modeling. This feature includes feedback on a shot to shot basis and adaptive control. Adaptive control permits the computer system to automatically adjust parameters after a shot, and to control the system to automatically compensate for time varying NBIS components. The Neutral Beam Power Supply features power supply modeling, fiber optic transmission of analog signals and digital control of power supply power-up/interlocks
Transport in low-dimensional mesoscopic systems
Energy Technology Data Exchange (ETDEWEB)
Syzranov, Sergey
2011-05-05
The work is devoted to the physics of graphene-based optoelectronics and arrays of Josephson junctions. The first part deals with transport in a graphene p-n junction irradiated by an electromagnetic field. The photocurrent in such device is calculated analytically and compared to those observed in the recent experiments on graphene photodetectors. It is shown that in a clean effectively one-dimensional junction the photocurrent oscillates as a function of gate voltages due to the interference between electron paths accompanied by the resonant photon absorption. The second part of the thesis is devoted to the construction of a Drude-like theory for the transport of Cooper pairs in weakly disordered Josephson networks and to finding the conductivity and the characteristic temperature of the commencement of strong localization. Also, it is shown that the low-temperature superconductor-insulator transition is necessarily of the first order in all 3D and in most 2D systems.
Three dimensional characterization and archiving system
International Nuclear Information System (INIS)
Sebastian, R.L.; Clark, R.; Gallman, P.
1996-01-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate
Space vector modulation strategy for neutral-point voltage balancing in three-level inverter systems
DEFF Research Database (Denmark)
Choi, Uimin; Lee, Kyo Beum
2013-01-01
This study proposes a space vector modulation (SVM) strategy to balance the neutral-point voltage of three-level inverter systems. The proposed method is implemented by combining conventional symmetric SVM with nearest three-vector (NTV) modulation. The conventional SVM is converted to NTV...... modulation by properly adding or subtracting a minimum gate-on time. In addition, using this method, the switching frequency is reduced and a decrease of switching loss would be yielded. The neutral-point voltage is balanced by the proposed SVM strategy without additional hardware or complex calculations....... Simulation and experimental results are shown to verify the validity and feasibility of the proposed SVM strategy....
DIII-D tokamak control and neutral beam computer system upgrades
International Nuclear Information System (INIS)
Penaflor, B.G.; McHarg, B.B.; Piglowski, D.A.; Pham, D.; Phillips, J.C.
2004-01-01
This paper covers recent computer system upgrades made to the DIII-D tokamak control and neutral beam computer systems. The systems responsible for monitoring and controlling the DIII-D tokamak and injecting neutral beam power have recently come online with new computing hardware and software. The new hardware and software have provided a number of significant improvements over the previous Modcomp AEG VME and accessware based systems. These improvements include the incorporation of faster, less expensive, and more readily available computing hardware which have provided performance increases of up to a factor 20 over the prior systems. A more modern graphical user interface with advanced plotting capabilities has improved feedback to users on the operating status of the tokamak and neutral beam systems. The elimination of aging and non supportable hardware and software has increased overall maintainability. The distinguishing characteristics of the new system include: (1) a PC based computer platform running the Redhat version of the Linux operating system; (2) a custom PCI CAMAC software driver developed by general atomics for the kinetic systems 2115 serial highway card; and (3) a custom developed supervisory control and data acquisition (SCADA) software package based on Kylix, an inexpensive interactive development environment (IDE) tool from borland corporation. This paper provides specific details of the upgraded computer systems
A novel reporter system for neutralizing and enhancing antibody assay against dengue virus.
Song, Ke-Yu; Zhao, Hui; Jiang, Zhen-You; Li, Xiao-Feng; Deng, Yong-Qiang; Jiang, Tao; Zhu, Shun-Ya; Shi, Pei-Yong; Zhang, Bo; Zhang, Fu-Chun; Qin, E-De; Qin, Cheng-Feng
2014-02-18
Dengue virus (DENV) still poses a global public health threat, and no vaccine or antiviral therapy is currently available. Antibody plays distinct roles in controlling DENV infections. Neutralizing antibody is protective against DENV infection, whereas sub-neutralizing concentration of antibody can increase DENV infection, termed antibody-dependent enhancement (ADE). Plaque-based assay represents the most widely accepted method measuring neutralizing or enhancing antibodies. In this study, a novel reporter virus-based system was developed for measuring neutralization and ADE activity. A stable Renilla luciferase reporter DENV (Luc-DENV) that can produce robust luciferase signals in BHK-21 and K562 cells were used to establish the assay and validated against traditional plaque-based assay. Luciferase value analysis using various known DENV-specific monoclonal antibodies showed good repeatability and a well linear correlation with conventional plaque-based assays. The newly developed assay was finally validated with clinical samples from infected animals and individuals. This reporter virus-based assay for neutralizing and enhancing antibody evaluation is rapid, lower cost, and high throughput, and will be helpful for laboratory detection and epidemiological investigation for DENV antibodies.
The TFTR 40 MW neutral beam injection system and DT operations
International Nuclear Information System (INIS)
Stevenson, T.; O'Connor, T.; Garzotto, V.
1995-01-01
Since December 1993, TFTR has performed DT experiments using tritium fuel provided mainly by neutral beam injection. Significant alpha particle populations and reactor-like conditions have been achieved at the plasma core, and fusion output power has risen to a record 10.7 MW using a record 40 MW NB heating. Tritium neutral beams have injected into over 480 DT plasmas and greater than 500 kCi have been processed through the neutral beam gas, cryo, and vacuum systems. Beam tritium injections, as well as tritium feedstock delivery and disposal, have now become part of routine operations. Shot reliability with tritium is about 90% and is comparable to deuterium shot reliability. This paper describes the neutral beam DT experience including the preparations, modifications, and operating techniques that led to this high level of success, as well as the critical differences in beam operations encountered during DT operations. Also, the neutral beam maintenance and repair history during DT operations, the corrective actions taken, and procedures developed for handling tritium contaminated components are discussed in the context of supporting a continuous DT program
Input-to-State Stabilizing MPC for Neutrally Stable Linear Systems subject to Input Constraints
Kim, Jung-Su; Yoon, Tae-Woong; Jadbabaie, Ali; Persis, Claudio De
2004-01-01
MPC(Model Predictive Control) is representative of control methods which are able to handle physical constraints. Closed-loop stability can therefore be ensured only locally in the presence of constraints of this type. However, if the system is neutrally stable, and if the constraints are imposed
Advances in the operation of the DIII-D neutral beam computer systems
International Nuclear Information System (INIS)
Phillips, J.C.; Busath, J.L.; Penaflor, B.G.; Piglowski, D.; Kellman, D.H.; Chiu, H.K.; Hong, R.M.
1998-02-01
The DIII-D neutral beam system routinely provides up to 20 MW of deuterium neutral beam heating in support of experiments on the DIII-D tokamak, and is a critical part of the DIII-D physics experimental program. The four computer systems previously used to control neutral beam operation and data acquisition were designed and implemented in the late 1970's and used on DIII and DIII-D from 1981--1996. By comparison to modern standards, they had become expensive to maintain, slow and cumbersome, making it difficult to implement improvements. Most critical of all, they were not networked computers. During the 1997 experimental campaign, these systems were replaced with new Unix compliant hardware and, for the most part, commercially available software. This paper describes operational experience with the new neutral beam computer systems, and new advances made possible by using features not previously available. These include retention and access to historical data, an asynchronously fired ''rules'' base, and a relatively straightforward programming interface. Methods and principles for extending the availability of data beyond the scope of the operator consoles will be discussed
Boublík, Milan; Riesová, Martina; Dubský, Pavel; Gaš, Bohuslav
2018-06-01
Conductivity detection is a universal detection technique often encountered in electrophoretic separation systems, especially in modern chip-electrophoresis based devices. On the other hand, it is sparsely combined with another contemporary trend of enhancing limits of detection by means of various preconcentration strategies. This can be attributed to the fact that a preconcentration experimental setup usually brings about disturbances in a conductivity baseline. Sweeping with a neutral sweeping agent seems a good candidate for overcoming this problem. A neutral sweeping agent does not hinder the conductivity detection while a charged analyte may preconcentrate on its boundary due to a decrease in its effective mobility. This study investigates such sweeping systems theoretically, by means of computer simulations, and experimentally. A formula is provided for the reliable estimation of the preconcentration factor. Additionally, it is demonstrated that the conductivity signal can significantly benefit from slowing down the analyte and thus the overall signal enhancement can easily overweight amplification caused solely by the sweeping process. The overall enhancement factor can be deduced a priori from the linearized theory of electrophoresis implemented in the PeakMaster freeware. Sweeping by neutral cyclodextrin is demonstrated on an amplification of a conductivity signal of flurbiprofen in a real drug sample. Finally, a possible formation of unexpected system peaks in systems with a neutral sweeping agent is revealed by the computer simulation and confirmed experimentally. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Start-up neutral-beam power supply system for MFTF
International Nuclear Information System (INIS)
Mooney, L.J.
1979-01-01
This paper describes some of the design features and considerations of the MFTF start-up neutral-beam power supplies. In particular, we emphasize features of the system that will ensure MFTF compatibility and achieve the required reliability/availability for the MFTF to be successful
Semiclassical neutral atom as a reference system in density functional theory.
Constantin, Lucian A; Fabiano, E; Laricchia, S; Della Sala, F
2011-05-06
We use the asymptotic expansions of the semiclassical neutral atom as a reference system in density functional theory to construct accurate generalized gradient approximations (GGAs) for the exchange-correlation and kinetic energies without any empiricism. These asymptotic functionals are among the most accurate GGAs for molecular systems, perform well for solid state, and overcome current GGA state of the art in frozen density embedding calculations. Our results also provide evidence for the conjointness conjecture between exchange and kinetic energies of atomic systems.
The Supervisory Control System for the HL-2A Neutral Beam Injector
Li, Bo; Li, Li; Feng, Kun; Wang, Xueyun; Yang, Jiaxing; Huang, Zhihui; Kang, Zihua; Wang, Mingwei; Zhang, Guoqing; Lei, Guangjiu; Rao, Jun
2009-06-01
Supervisory control and protection system of the neutral beam injector (NBI) in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based on computer networks with its transmission medium of optical fiber, its advantages in high operational stability, reliability, security and flexible functional expandability are clearly shown during the NBI commissioning and heating experiment in HL-2A.
Characteristics of earth faults in power systems with a compensated or an unearthed neutral
Energy Technology Data Exchange (ETDEWEB)
Haenninen, S; Lehtonen, M [VTT Energy, Espoo (Finland); Antila, E [ABB Transmit Oy (Finland); Stroem, J [Espoo Electricity Co (Finland); Ingman, S [Vaasa Electricity Co (Finland)
1998-08-01
The most common fault type in the electrical distribution networks is the single phase to earth fault. For instance in the Nordic countries, about 80 % of all faults are of this type. To develop the protection and fault location systems, it is important to obtain real case data of disturbances and faults which occurred in the networks. Therefore, data of fault occurrences have been recorded and analyzed in the medium voltage distribution networks (20 kV) at two substations, of which one has an isolated and the other a compensated neutral. In the occurring disturbances, the traces of phase currents and neutral currents in the beginning of two feeder and the traces of phase voltages and neutral voltage from the voltage measuring bay were recorded. In addition to the measured data, other information of the fault occurrences was also collected (data of the line, cause and location of permanent faults and so on)
Three dimensional characterization and archiving system
Energy Technology Data Exchange (ETDEWEB)
Sebastian, R.L.; Clark, R.; Gallman, P. [Coleman Research Corp., Springfield, VA (United States)] [and others
1995-10-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.
Robust H∞ Control of Neutral System with Time-Delay for Dynamic Positioning Ships
Directory of Open Access Journals (Sweden)
Dawei Zhao
2015-01-01
Full Text Available Due to the input time-delay existing in most thrust systems of the ships, the robust H∞ controller is designed for the ship dynamic positioning (DP system with time-delay. The input delay system is turned to a neutral time-delay system by a state-derivative control law. The less conservative result is derived for the neutral system with state-derivative feedback by the delay-decomposition approach and linear matrix inequality (LMI. Finally, the numerical simulations demonstrate the asymptotic stability and robustness of the controller and verify that the designed DP controller is effective in the varying environment disturbances of wind, waves, and ocean currents.
Coupled two-dimensional edge-plasma and neutral gas modelling of the DIII-D scrape-off-layer
International Nuclear Information System (INIS)
Maingi, R.; Gilligan, J.; Hankins, O.; Rensink, M.; Owen, L.; Klepper, C.; Mioduszewski, P.
1992-01-01
This paper reports that in order to do consistent scrape-off-layer plasma and neutral transport calculations, the 2-D fluid code, B2 has been externally coupled to the neutral transport code, DEGAS, for Dlll-D. The coupling procedure is similar to recent simulations done for TFTR, Tore Supra, and ClT. An averaged source approach is utilized to allow convergence between the two codes. Initial comparison of plasma quantities between the coupled code set and the B2 code alone shows that a colder, denser plasma may exist at the divertor targets than predicted by the B2 code with its internal recycling model
Design study of a neutral beam injection system for the JAERI Experimental Fusion Reactor (JXFR)
International Nuclear Information System (INIS)
1977-10-01
Design study has been made of a 200 kV, 45 MW D 0 neutral beam injection system for the JAERI Experimental Fusion Reactor (JXFR) covering the following: determination of the ion source specifications, design of components such as ion source with extraction electrodes, energy converter, cryopump and cooling system, and estimations of the energy conversion efficiency, overall power efficiency and total power required for operation of the NBI system, and also a hydrogen isotope separation method using cryo-sorption pumps. Optimizations and parameter studies of the neutralizing cell length, gas flow rate, operating pressure of ion sources, total pumping speed and pressure of energy converters are made in the design study based on reactor plasma requirements. Hollow cathode ion sources are proposed because of the extended operation time at low gas pressure (about 4.5 x 10 -3 Torr) and the high gas efficiency (40%). Life of the extraction electrodes is determined by blistering due to deuterium ions. Fast neutron radiation damage is relatively small. In-line direct converters with grounded recovery electrodes and neutralizing cells floated at negative potential -190 kV are used to recover residual deuterium ion energy without interrupting the neutral beam trajectories. Energy conversion efficiency of 80% and overall power efficiency of about 40% are obtained. (auth.)
Magnetic analysis of the magnetic field reduction system of the ITER neutral beam injector
Energy Technology Data Exchange (ETDEWEB)
Barrera, Germán, E-mail: german.barrera@ciemat.es [CIEMAT, Laboratorio Nacional de Fusión, Avda. Complutense 22, 28040 Madrid (Spain); Ahedo, Begoña; Alonso, Javier; Ríos, Luis [CIEMAT, Laboratorio Nacional de Fusión, Avda. Complutense 22, 28040 Madrid (Spain); Chareyre, Julien; El-Ouazzani, Anass [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Agarici, Gilbert [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 07/08, 08019 Barcelona (Spain)
2015-10-15
The neutral beam system for ITER consists of two heating and current drive neutral beam injectors (HNB) and a diagnostic neutral beam (DNB) injector. The proposed physical plant layout allows a possible third HNB injector to be installed later. For the correct operation of the beam, the ion source and the ion path until it is neutralized must operate under a very low magnetic field environment. To prevent the stray ITER field from penetrating inside those mentioned critical areas, a magnetic field reduction system (MFRS) will envelop the beam vessels and the high voltage transmission lines to ion source. This system comprises the passive magnetic shield (PMS), a box like assembly of thick low carbon steel plates, and the Active Correction and Compensation Coils (ACCC), a set of coils carrying a current which depends on the tokamak stray field. This paper describes the magnetic model and analysis results presented at the PMS and ACCC preliminary design review held in ITER organization in April 2013. The paper focuses on the magnetic model description and on the description of the analysis results. The iterative process for obtaining optimized currents in the coils is presented. The set of coils currents chosen among the many possible solutions, the magnetic field results in the interest regions and the fulfillment of the magnetic field requirements are described.
Three dimensional characterization and archiving system
International Nuclear Information System (INIS)
Sebastian, R.L.; Clark, R.; Gallman, P.
1995-01-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D ampersand D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D ampersand D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations
Recent improvements to the DIII-D neutral beam instrumentation and control system
International Nuclear Information System (INIS)
Kellman, D.H.; Hong, R.
1997-11-01
The DIII-D neutral beam (NB) instrumentation and control (I and C) system provides for operational control and synchronization of the eight DIII-D neutral beam injection systems, as well as for pertinent data acquisition and safety interlocking. Recently, improvements were made to the I and C system. With the replacement of the NB control computers, new signal interfacing was required to accommodate the elimination of physical operator panels, in favor of graphical user interface control pages on computer terminal screens. The program in the mode control (MC) programmable logic controller (PLC), which serves as a logic-processing interface between the NB control computers and system hardware, was modified to improve the availability of NB heating of DIII-D plasmas in the event that one or more individual beam systems suddenly become unavailable while preparing for a tokamak experimental shot sequences. An upgraded computer platform was adopted for the NB control system operator interface and new graphical user interface pages were developed to more efficiently display system status data. A failure mode of the armor tile infrared thermometers (pyrometers), which serve to terminate beam pulsing if beam shine-through overheats wall thermal shielding inside the DIII-D tokamak, was characterized such that impending failures can be detected and repairs effected to mitigate beam system down-time. The hardware that controls gas flow to the beamline neutralizer cells was upgraded to reduce susceptibility to electromagnetic interference (EMI), and interlocking was provided to terminate beam pulsing in the event of insufficient neutralizer gas flow. Motivation, implementation, and results of these improvements are presented
Progress in the design of the ITER Neutral Beam cell Remote Handling System
Energy Technology Data Exchange (ETDEWEB)
Shuff, R., E-mail: robin.shuff@f4e.europa.eu [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Van Uffelen, M.; Damiani, C. [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Tesini, A.; Choi, C.-H. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul-lez-Durance (France); Meek, R. [Oxford Technologies Limited, 7 Nuffield Way, Abingdon OX14 1RL (United Kingdom)
2014-10-15
The ITER Neutral Beam cell will include a suite of Remote Handling equipment for maintenance tasks. This paper summarises the current status and recent developments in the design of the ITER Neutral Beam Remote Handling System. Its concept design was successfully completed in July 2012 by CCFE in the frame of a grant agreement with F4E, in collaboration with the ITER Organisation, including major systems like monorail crane, Beam Line Transporter, beam source equipment, upper port and neutron shield equipment and associated tooling. Research and development activities are now underway on the monorail crane radiation hardened on-board control system and first of a kind remote pipe and lip seal maintenance tooling for the beam line vessel, reported in this paper.
A rule-based computer control system for PBX-M neutral beams
International Nuclear Information System (INIS)
Frank, K.T.; Kozub, T.A.; Kugel, H.W.
1987-01-01
The Princeton Beta Experiment (PBX) neutral beams have been routinely operated under automatic computer control. A major upgrade of the computer configuration was undertaken to coincide with the PBX machine modification. The primary tasks included in the computer control system are data acquisition, waveform reduction, automatic control and data storage. The portion of the system which will remain intact is the rule-based approach to automatic control. Increased computational and storage capability will allow the expansion of the knowledge base previously used. The hardware configuration supported by the PBX Neutral Beam (XNB) software includes a dedicated Microvax with five CAMAC crates and four process controllers. The control algorithms are rule-based and goal-driven. The automatic control system raises ion source electrical parameters to selected energy goals and maintains these levels until new goals are requested or faults are detected
Progress in the design of the ITER Neutral Beam cell Remote Handling System
International Nuclear Information System (INIS)
Shuff, R.; Van Uffelen, M.; Damiani, C.; Tesini, A.; Choi, C.-H.; Meek, R.
2014-01-01
The ITER Neutral Beam cell will include a suite of Remote Handling equipment for maintenance tasks. This paper summarises the current status and recent developments in the design of the ITER Neutral Beam Remote Handling System. Its concept design was successfully completed in July 2012 by CCFE in the frame of a grant agreement with F4E, in collaboration with the ITER Organisation, including major systems like monorail crane, Beam Line Transporter, beam source equipment, upper port and neutron shield equipment and associated tooling. Research and development activities are now underway on the monorail crane radiation hardened on-board control system and first of a kind remote pipe and lip seal maintenance tooling for the beam line vessel, reported in this paper
Structures of two-dimensional three-body systems
International Nuclear Information System (INIS)
Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.
1996-01-01
Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)
Systems approach for condition management design: JET neutral beam system-A fusion case study
Energy Technology Data Exchange (ETDEWEB)
Khella, M., E-mail: M.Khella@lboro.ac.uk [Systems Engineering Innovation Centre (SEIC) - BAE Systems, Loughborough University, Holywell Park, Leicestershire LE11 3TU (United Kingdom); Pearson, J. [Systems Engineering Innovation Centre (SEIC) - BAE Systems, Loughborough University, Holywell Park, Leicestershire LE11 3TU (United Kingdom); Dixon, R. [Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Ciric, D.; Day, I.; King, R.; Milnes, J.; Stafford-Allen, R. [EURATOM/CCFE Fusion Association, Culham Science Centre, Oxfordshire OX14 3DB (United Kingdom)
2011-10-15
The maturation of any new technology can be coarsely divided into three stages of a development lifecycle: (1) fundamental research, (2) experimental rig development and testing through to (3) commercialization. With the enhancement of machines like JET, the building of ITER and the initiation of DEMO design activities, the fusion community is moving from stages 1 and 2 towards stage 3. One of the consequences of this transition will be a shift in emphasis from scientific achievement to maximizing machine reliability and availability. The fusion community should therefore be preparing itself for this shift by examining all methods and tools utilized in established engineering sectors that might help to improve these fundamental performance parameters. To this end, the Culham Centre for Fusion Energy (CCFE) has proactively engaged with UK industry to examine whether the development of condition management (CM) systems could help improve such performance parameters. This paper describes an initial CM design case study on the JET neutral beam system. The primary output of this study was the development of a CM design methodology that captures existing experience in fault detection, and classification as well as new methods for fault diagnosis. A summary of the methods used and the potential benefits of data fusion are presented here.
Smooth controllability of infinite-dimensional quantum-mechanical systems
International Nuclear Information System (INIS)
Wu, Re-Bing; Tarn, Tzyh-Jong; Li, Chun-Wen
2006-01-01
Manipulation of infinite-dimensional quantum systems is important to controlling complex quantum dynamics with many practical physical and chemical backgrounds. In this paper, a general investigation is casted to the controllability problem of quantum systems evolving on infinite-dimensional manifolds. Recognizing that such problems are related with infinite-dimensional controllability algebras, we introduce an algebraic mathematical framework to describe quantum control systems possessing such controllability algebras. Then we present the concept of smooth controllability on infinite-dimensional manifolds, and draw the main result on approximate strong smooth controllability. This is a nontrivial extension of the existing controllability results based on the analysis over finite-dimensional vector spaces to analysis over infinite-dimensional manifolds. It also opens up many interesting problems for future studies
DISSOLVED OXYGEN REDUCTION IN THE DIII-D NEUTRAL BEAM ION SOURCE COOLING SYSTEM
International Nuclear Information System (INIS)
YIP, H.; BUSATH, J.; HARRISON, S.
2004-03-01
OAK-B135 Neutral beam ion sources (NBIS) are critical components for the neutral beam injection system supporting the DIII-D tokamak. The NBIS must be cooled with 3028 (ell)/m (800 gpm) of de-ionized and de-oxygenated water to protect the sources from overheating and failure. These ions sources are currently irreplaceable. Since the water cooled molybdenum components will oxidize in water almost instantaneously in the presence of dissolved oxygen (DO), de-oxygenation is extremely important in the NBIS water system. Under normal beam operation the DO level is kept below 5 ppb. However, during weeknights and weekends when neutral beam is not in operation, the average DO level is maintained below 10 ppb by periodic circulation with a 74.6 kW (100 hp) pump, which consumes significant power. Experimental data indicated evidence of continuous oxygen diffusion through non-metallic hoses in the proximity of the NBIS. Because of the intermittent flow of the cooling water, the DO concentration at the ion source(s) could be even higher than measured downstream, and hence the concern of significant localized oxidation/corrosion. A new 3.73 kW (5 hp) auxiliary system, installed in the summer of 2003, is designed to significantly reduce the peak and the time-average DO levels in the water system and to consume only a fraction of the power
Multiple track Doppler-shift spectroscopy system for TFTR neutral beam injectors
International Nuclear Information System (INIS)
Kamperschroer, J.H.; Kugel, H.W.; Reale, M.A.
1986-09-01
A Doppler-shift spectroscopy system has been installed on the TFTR neutral beam injection system to measure species composition during both conditioning and injection pulses. Two intensified vidicon detectors and two spectrometers are utilized in a system capable of resolving data from up to twelve ion sources simultaneously. By imaging the light from six ion sources onto one detector, a cost-effective system has been achieved. Fiber optics are used to locate the diagnostic in an area remote from the hazards of the tokamak test cell allowing continuous access, and eliminating the need for radiation shielding of electronic components. Automatic hardware arming and interactive data analysis allow beam composition to be computed between tokamak shots for use in analyzing plasma heating experiments. Measurements have been made using lines of sight into both the neutralizer and the drift duct. Analysis of the data from the drift duct is both simpler and more accurate since only neutral particles are present in the beam at this location. Comparison of the data taken at these two locations reveals the presence of partially accelerated particles possessing an estimated 1/e half-angle divergence of 15 0 and accounting for up to 30% of the extracted power
Unmanned Aerial System Four-Dimensional Gunnery Training Device Development
2017-10-01
Aerial System (UAS) Four-Dimensional Gunnery Training Device: Training Effectiveness Assessment (James & Miller, in press). 31 Technical ...Research Product 2018-05 Unmanned Aerial System Four-Dimensional Gunnery Training Device Development David R. James...for the Department of the Army by Northrop Grumman Corporation. Technical review by Thomas Rhett Graves, Ph.D., U.S. Army Research Institute
CP, T, and CPT violation in the neutral kaon system at the CPLEAR experiment
Adler, R; Angelopoulos, Angelos; Aslanides, Elie; Backenstoss, Gerhard; Bee, C P; Behnke, O; Bennet, J; Bertin, V; Blanc, F; Bloch, P; Bula, C; Carlson, P J; Carroll, M; Carvalho, J; Cawley, E; Charalambous, S; Chardalas, M; Chardin, G; Chertok, M B; Cody, A; Danielsson, M; Dedoussis, S; Dejardin, M; Derré, J; Dodgson, M; Duclos, J; Ealet, A; Eckart, B; Eleftheriadis, C; Evangelou, I; Faravel, L; Fassnacht, P; Faure, J L; Felder, C; Ferreira-Marques, R; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Garreta, D; Geralis, T; Gerber, H J; Gumplinger, P; Go, A; Guyot, C; Haselden, A; Hayman, P J; Henry-Coüannier, F; Hollander, R W; Hubert, E; Jansson, K; Johner, H U; Jon-And, K; Kettle, P R; Kochowski, Claude; Kokkas, P; Kreuger, R; Lawry, T; Le Gac, R; Leimgruber, F; Liolios, A; Machado, E; Maley, P; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Nakada, Tatsuya; Onofre, A; Pagels, B; Pavlopoulos, P; Pelucchi, F; Pinto da Cunha, J; Policarpo, Armando; Polivka, G; Postma, H; Rickenbach, R; Roberts, B L; Rozaki, E; Ruf, T; Sacks, L; Sakelliou, L; Sanders, P; Santoni, C; Sarigiannis, K; Schäfer, M; Schaller, L A; Schopper, A; Schune, P; Soares, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; Triantis, F A; Tröster, D A; Van Beveren, E; van Eijk, C W E; Vlachos, S; Weber, P; Wigger, O; Witzig, C; Wolter, M; Yéche, C; Zavrtanik, D; Zimmerman, D
1996-01-01
The essential characteristics of the neutral kaon system and the way CP, T, and possible CPT violations may be observed in it are recalled. The principle of the CPLEAH experiment is presented CPLEAH experimental results in the semi-leptonic decay channels are given and discussed. It is shown, in particular, that direct. time reversal invariance violation will be experimentally observed for the first time.
Efficient, radiation-hardened, 400- and 800-keV neutral-beam injection systems
International Nuclear Information System (INIS)
Anderson, O.A.; Cooper, W.S.; Fink, J.A.; Goldberg, D.A.; Ruby, L.; Soroka, L.; Tanabe, J.
1983-04-01
We present designs for two negative-ion based neutral beam lines with reactor-level power output. Both beam lines make use of such technologically advanced features as high-current-density surface-conversion ion sources, transverse-field-focussing (TFF) acceleration and transport, and laser photodetachment. For the second of these designs, we also presented detailed beam and vacuum calculations, as well as a brief description of a proof-of-principle test system currently under development
Simultaneous Hydrogen Generation and Waste Acid Neutralization in a Reverse Electrodialysis System
Hatzell, Marta C.
2014-09-02
Waste acid streams produced at industrial sites are often co-located with large sources of waste heat (e.g., industrial exhaust gases, cooling water, and heated equipment). Reverse electrodialysis (RED) systems can be used to generate electrical power and hydrogen gas using waste heat-derived solutions, but high electrode overpotentials limit system performance. We show here that an ammonium bicarbonate (AmB) RED system can achieve simultaneous waste acid neutralization and in situ hydrogen production, while capturing energy from excess waste heat. The rate of acid neutralization was dependent on stack flow rate and increased 50× (from 0.06 ± 0.04 to 3.0 ± 0.32 pH units min -1 m-2 membrane), as the flow rate increased 6× (from 100 to 600 mL min-1). Acid neutralization primarily took place due to ammonium electromigration (37 ± 4%) and proton diffusion (60 ± 5%). The use of a synthetic waste acid stream as a catholyte (pH ≈ 2) also increased hydrogen production rates by 65% (from 5.3 ± 0.5 to 8.7 ± 0.1 m3 H2 m-3 catholyte day -1) compared to an AmB electrolyte (pH ≈ 8.5). These findings highlight the potential use of dissimilar electrolytes (e.g., basic anolyte and acidic catholyte) for enhanced power and hydrogen production in RED stacks. © 2014 American Chemical Society.
Local and global Hopf bifurcation analysis in a neutral-type neuron system with two delays
Lv, Qiuyu; Liao, Xiaofeng
2018-03-01
In recent years, neutral-type differential-difference equations have been applied extensively in the field of engineering, and their dynamical behaviors are more complex than that of the delay differential-difference equations. In this paper, the equations used to describe a neutral-type neural network system of differential difference equation with two delays are studied (i.e. neutral-type differential equations). Firstly, by selecting τ1, τ2 respectively as a parameter, we provide an analysis about the local stability of the zero equilibrium point of the equations, and sufficient conditions of asymptotic stability for the system are derived. Secondly, by using the theory of normal form and applying the theorem of center manifold introduced by Hassard et al., the Hopf bifurcation is found and some formulas for deciding the stability of periodic solutions and the direction of Hopf bifurcation are given. Moreover, by applying the theorem of global Hopf bifurcation, the existence of global periodic solution of the system is studied. Finally, an example is given, and some computer numerical simulations are taken to demonstrate and certify the correctness of the presented results.
Software upgrade for the DIII-D neutral beam control systems
International Nuclear Information System (INIS)
Cummings, J.W.; Thurgood, P.A.
1991-11-01
The neutral beams are used to heat the plasma in the DIII-D tokamak, a fusion energy research experiment operated by General Atomics (GA) and funded by the Department of Energy (DOE). The experiment is dedicated to demonstrating noninductive current drive of high beta high temperature divertor plasma with good confinement. The neutral beam heating system for the DIII-D tokamak uses four MODCOMP Classic computers for data acquisition and control of the four beamlines. The Neutral Beam Software Upgrade project was launched in early 1990. The major goals were to upgrade the MAX IV operating system to the latest revision (K.1), use standard MODCOMP software (as much as possible), and to develop a very ''user friendly,'' versatile system. Accomplishing these goals required new software to be developed and modifications to existing applications software to make it compatible with the latest operating system. The custom operating system modules to handle the message service and interrupt handling were replaced by the standard MODCOMP Inter Task Communication (ITC) and interrupt routines that are part of the MAX IV operating system. The message service provides the mechanism for doing shot task sequencing (task scheduling). The interrupt routines are used to connect external interrupts to the system. The new software developed consists of a task dispatcher, screen manager, and interrupt tasks. The existing applications software had to be modified to be compatible with the MODCOMP ITC services and consists of the Modcomp Infinity Data Base Manager, a multi-user system, and menu-driven operating system interface routines using the Infinity Data Base Manager
Test facility for the development of 150-keV, multi-megawatt neutral beam systems
International Nuclear Information System (INIS)
Haughian, W.; Baker, W.R.; Biagi, L.A.; Hopkins, D.B.
1975-11-01
The next generation of CTR experiments, such as the Tokamak Fusion Test Reactor (TFTR), will require neutral-beam injection systems that produce multi-megawatt, 120-keV deuterium-beam pulses of 0.5-second duration. Since present injection systems are operating in the 10- to 40-keV range, an intensive development effort is in progress to meet a 150-keV requirement. The vacuum system and power supplies that make up a test facility to be used in the development of these injectors are described
Measurements of Discrete Symmetries in the Neutral Kaon System with the CPLEAR (PS195) Experiment
Ruf, Thomas
2015-07-01
The antiproton storage ring LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of T, \\{CPT} and \\{CP} symmetries in the neutral kaon system. It measured with high precision the time evolution of initially strangeness-tagged K0 and overline K ^0 states to determine the size of violations with respect to these symmetries in the context of a systematic study. In parallel, limits concerning quantum-mechanical predictions (EPR paradox, coherence of the wave function) or the equivalence principle of general relativity have been obtained. This article will first discuss briefly the unique low energy antiproton storage ring LEAR followed by a description of the CPLEAR experiment, including the basic formalism necessary to understand the time evolution of a neutral kaon state and the main results related to measurements of discrete symmetries in the neutral kaon system. An excellent and exhaustive review of the CPLEAR experiment and all its measurements is given in Ref. 1.
Operating characteristics of a new ion source for KSTAR neutral beam injection system.
Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul
2014-02-01
A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.
System catalytic neutralization control of combustion engines waste gases in mining technologies
Korshunov, G. I.; Solnitsev, R. I.
2017-10-01
The paper presents the problems solution of the atmospheric air pollution with the exhaust gases of the internal combustion engines, used in mining technologies. Such engines are used in excavators, bulldozers, dump trucks, diesel locomotives in loading and unloading processes and during transportation of minerals. NOx, CO, CH emissions as the waste gases occur during engine operation, the concentration of which must be reduced to the standard limits. The various methods and means are used for the problem solution, one of which is neutralization based on platinum catalysts. A mathematical model of a controlled catalytic neutralization system is proposed. The simulation results confirm the increase in efficiency at start-up and low engine load and the increase in the catalyst lifetime.
Efficient, radiation-hardened, 800-keV neutral beam injection system
International Nuclear Information System (INIS)
Anderson, O.A.; Cooper, W.S.; Goldberg, D.A.; Ruby, L.; Soroka, L.; Fink, J.H.
1982-10-01
Recent advances and new concepts in negative ion generation, transport, acceleration, and neutrailzation make it appear likely that an efficient, radiation-hardened neutral beam injection system could be developed in time for the proposed FED-A tokamak. These new developments include the operation of steady-state H - ion sources at over 5 A per meter of source length, the concept of using strong-focussing electrostatic structures for low-gradient dc acceleration of high-current sheet beams of negative ions and the transport of these beams around corners, and the development of powerful oxygen-iodine chemical lasers which will make possible the efficient conversion of the negative ions to neutrals using a photodetachment scheme in which the ion beam passes through the laser cavity
Contribution of CPLEAR to the physics of the neutral-kaon system
International Nuclear Information System (INIS)
Angelopoulos, A.; Apostolakis, A.; Aslanides, E.; Backenstoss, G.; Bargassa, P.; Behnke, O.; Benelli, A.; Bertin, V.; Blanc, F.; Bloch, P.; Carlson, P.; Carroll, M.; Cawley, E.; Chertok, M.B.; Danielsson, M.; Dejardin, M.; Derre, J.; Ealet, A.; Eleftheriadis, C.A.; Faravel, L.; Fetscher, W.; Fidecaro, M.; Filipcic, A.; Francis, D.; Fry, J.; Gabathuler, E.; Gamet, R.; Gerber, H.-J.; Go, A.; Haselden, A.; Hayman, P.J.; Henry-Couannier, F.; Hollander, R.W.; Jon-And, K.; Kettle, P.-R.; Kokkas, P.; Kreuger, R.; Le Gac, R.; Leimgruber, F.; Mandic, I.; Manthos, N.; Marel, G.; Mikuz, M.; Miller, J.; Montanet, F.; Muller, A.; Nakada, T.; Pagels, B.; Papadopoulos, I.; Pavlopoulos, P.; Polivka, G.; Rickenbach, R.; Roberts, B.L.; Ruf, T.; Schaefer, M.; Schaller, L.A.; Schietinger, T.; Schopper, A.; Schune, P.; Tauscher, L.; Thibault, C.; Touchard, F.; Touramanis, C.; Van Eijk, C.W.E.; Vlachos, S.; Weber, P.; Wigger, O.; Wolter, M.; Zavrtanik, D.; Zimmerman, D.
1999-01-01
We report the results of the CPLEAR experiment on CP-, T- and CPT-symmetries in the neutral kaon system. CP-violation parameters are given for different decay channels. For the first time T-violation is measured by a direct method using semileptonic decays. The CPT symmetry in the kaons decays is tested through the parameters Im(δ), from the Bell-Steinberger relation, with a precision of 10 -5 and Re(δ) with a precision of a few 10 -4 (two order of magnitude better than the previous measurement). These two measurements allow us to bound the difference in mass and width of K 0 and K-bar 0 to be equal within 10 -18 GeV. In the limit of CPT invariance in the neutral kaon decays, the K 0 and K-bar 0 masses are equal within 10 -19 GeV
An alpha particle measurement system using an energetic neutral helium beam in ITER (invited)
Energy Technology Data Exchange (ETDEWEB)
Sasao, M.; Tanaka, N.; Terai, K.; Kaneko, O. [Graduate school of Engineering, Tohoku University, Sendai 980-8579 (Japan); Kisaki, M.; Kobuchi, T.; Tsumori, K.; Okamoto, A.; Kitajima, S. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Shinto, K. [IFMIF R and D Center, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Wada, M. [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)
2012-02-15
An energetic helium neutral beam is involved in the beam neutralization measurement system of alpha particles confined in a DT fusion plasma. A full size strong-focusing He{sup +} ion source (2 A, the beam radius of 11.3 mm, the beam energy less than 20 keV). Present strong-focusing He{sup +} ion source shows an emittance diagram separated for each beamlet of multiple apertures without phase space mixing, despite the space charge of a beamlet is asymmetric and the beam flow is non-laminar. The emittance of beamlets in the peripheral region was larger than that of center. The heat load to the plasma electrode was studied to estimate the duty factor for the ITER application.
International Nuclear Information System (INIS)
Roberds, R.M.
1975-01-01
A space-angle synthesis (SAS) method has been developed for treating the steady-state, two-dimensional transport of neutrons and gamma rays from a point source of simulated nuclear weapon radiation in air. The method was validated by applying it to the problem of neutron transport from a point source in air over a ground interface, and then comparing the results to those obtained by DOT, a state-of-the-art, discrete-ordinates code. In the SAS method, the energy dependence of the Boltzmann transport equation was treated in the standard multigroup manner. The angular dependence was treated by expanding the flux in specially tailored trial functions and applying the method of weighted residuals which analytically integrated the transport equation over all angles. The weighted-residual approach was analogous to the conventional spherical-harmonics (P/sub N/) method with the exception that the tailored expansion allowed for more rapid convergence than a spherical-harmonics P 1 expansion and resulted in a greater degree of accuracy. The trial functions used in the expansion were odd and even combinations of selected trial solutions, the trial solutions being shaped ellipsoids which approximated the angular distribution of the neutron flux in one-dimensional space. The parameters which described the shape of the ellipsoid varied with energy group and the spatial medium, only, and were obtained from a one-dimensional discrete-ordinates calculation. Thus, approximate transport solutions were made available for all two-dimensional problems of a certain class by using tabulated parameters obtained from a single, one-dimensional calculation
Quantum confinement effects in low-dimensional systems
Indian Academy of Sciences (India)
2015-06-03
Jun 3, 2015 ... Quantum confinement effects in low-dimensional systems. Figure 5. (a) Various cuts of the three-dimensional data showing energy vs. momen- tum dispersion relations for Ag film of 17 ML thickness on Ge(111). (b) Photo- emission intensity maps along ¯M– ¯ – ¯K direction. (c) Substrate bands replotted ...
Study of one dimensional magnetic system via field theory
International Nuclear Information System (INIS)
Talim, S.L.
1988-04-01
We present a study of one-dimensional magnetic system using field theory methods. We studied the discreteness effects in a classical anisotropic one dimensional antiferromagnet in an external magnetic field. It is shown that for TMMC, at the temperatures and magnetic fields where most experiments have been done, the corrections are small and can be neglected. (author)
Tandem-Mirror Experiment-Upgrade neutral pressure measurement diagnostic systems
International Nuclear Information System (INIS)
Pickles, W.L.; Allen, S.L.; Hill, D.N.; Hunt, A.L.; Simonen, T.C.
1985-01-01
The Tandem-Mirror Experiment-Upgrade (TMX-U) has a large and complex system of Bayard--Alpert, magnetron, and Penning gauges, in addition to mass spectrometers (RGA), all of which measure neutral pressures in the many internal regions of TMX-U. These pressure measurements are used as part of the confinement physics data base as well as for management of the TMX-U vacuum system. Dynamic pressures are modeled by a coupled-volumes simulation code, which includes wall reflux, getter pumping, and plasma pumping
Directory of Open Access Journals (Sweden)
Yajun Li
2015-01-01
Full Text Available This paper deals with the robust H∞ filter design problem for a class of uncertain neutral stochastic systems with Markovian jumping parameters and time delay. Based on the Lyapunov-Krasovskii theory and generalized Finsler Lemma, a delay-dependent stability condition is proposed to ensure not only that the filter error system is robustly stochastically stable but also that a prescribed H∞ performance level is satisfied for all admissible uncertainties. All obtained results are expressed in terms of linear matrix inequalities which can be easily solved by MATLAB LMI toolbox. Numerical examples are given to show that the results obtained are both less conservative and less complicated in computation.
Design of Filter for a Class of Switched Linear Neutral Systems
Directory of Open Access Journals (Sweden)
Caiyun Wu
2013-01-01
Full Text Available This paper is concerned with the filtering problem for a class of switched linear neutral systems with time-varying delays. The time-varying delays appear not only in the state but also in the state derivatives. Based on the average dwell time approach and the piecewise Lyapunov functional technique, sufficient conditions are proposed for the exponential stability of the filtering error dynamic system. Then, the corresponding solvability condition for a desired filter satisfying a weighted performance is established. All the conditions obtained are delay-dependent. Finally, two numerical examples are given to illustrate the effectiveness of the proposed theory.
Integrable finite-dimensional systems related to Lie algebras
International Nuclear Information System (INIS)
Olshanetsky, M.A.; Perelomov, A.M.
1979-01-01
Some solvable finite-dimensional classical and quantum systems related to the Lie algebras are considered. The dynamics of these systems is closely related to free motion on symmetric spaces. In specific cases the systems considered describe the one-dimensional n-body problem recently considered by many authors. The review represents from general and universal point of view the results obtained during the last few years. Besides, it contains some results both of physical and mathematical type
Software upgrade for the DIII-D neutral beam control systems
International Nuclear Information System (INIS)
Cummings, J.W.; Thurgood, P.A.
1992-01-01
This paper reports on the Neutral Beam Software Upgrade project which was launched in early 1990. The major goals were to upgrade the MAC IV operating system to the latest revision (K.1), use standard MODCOMP software (as much as possible), and to develop a very user friendly, versatile system. Accomplishing these goals required new software to be developed and modifications to existing applications software to make it compatible with the latest operating system. The custom operating system modules to handle the message service and interrupt handling were replaced by the standard MODCOMP Inter Task Communication (ITC) and interrupt routines that are part of the MAX IV operating system. The message service provides the mechanism for doing shot task sequencing (task scheduling). The interrupt routines are used to connect external irterrupts to the system
Energy Technology Data Exchange (ETDEWEB)
Kim, Myungsu; Lim, Heoksoon; Na, Janghwan; Chi, Moongoo [Korea Hydro and Nuclear Power Co. Ltd. Central Research Institute, Daejeon (Korea, Republic of)
2015-05-15
It is focusing on development of a new designing process which can be compatible to international standards such as IAEA1 and NRC2 suggest. Evaluation for the design effectiveness was found as one of the areas to improve. If a design doesn't meet a certain level of effectiveness, it should be re-designed accordingly. The effectiveness can be calculated with combination of probability of Interruption and probability of neutralization. System Analysis of Vulnerability to Intrusion (SAVI) has been developed by Sandia National Laboratories for that purpose. With SNL's timely detection methodology, SAVI has been used by U.S. nuclear utilities to meet the NRC requirements for PPS design effectiveness evaluation. For the SAVI calculation, probability of neutralization is a vital input element that must be supplied. This paper describes the elements to consider for neutralization, probability estimation methodology, and the estimation for APR1400 PPS design effectiveness evaluation process. Markov chain and Monte Carlo simulation are often used for simple numerical calculation to estimate P{sub N}. The results from both methods are not always identical even for the same situation. P{sub N} values for APR1400 evaluation were calculated based on Markov chain method and modified to be applicable for guards/adversaries ratio based analysis.
Mayer coefficients in two-dimensional Coulomb systems
International Nuclear Information System (INIS)
Speer, E.R.
1986-01-01
It is shown that, for neutral systems of particles of arbitrary charges in two dimensions, with hard cores, coefficients of the Mayer series for the pressure exist in the thermodynamic limit below certain thresholds in the temperature. The methods used here apply also to correlation functions and yield bounds on the asymptotic behavior of their Mayer coefficients
International Nuclear Information System (INIS)
Kaneko, Yuta; Yoshida, Zensho
2014-01-01
Introducing a Clebsch-like parameterization, we have formulated a canonical Hamiltonian system on a symplectic leaf of reduced magnetohydrodynamics. An interesting structure of the equations is in that the Lorentz-force, which is a quadratic nonlinear term in the conventional formulation, appears as a linear term −ΔQ, just representing the current density (Q is a Clebsch variable, and Δ is the two-dimensional Laplacian); omitting this term reduces the system into the two-dimensional Euler vorticity equation of a neutral fluid. A heuristic estimate shows that current sheets grow exponentially (even in a fully nonlinear regime) together with the action variable P that is conjugate to Q. By numerical simulation, the predicted behavior of the canonical variables, yielding exponential growth of current sheets, has been demonstrated
International Nuclear Information System (INIS)
Walters, W.F.; Brinkley, F.W.; Marr, D.R.
1984-10-01
TWOHEX solves the two-dimensional multigroup transport equation on an equilateral triangular mesh in the x,y plane. Both regular and adjoint, inhomogeneous (fixed source) and homogeneous problems are solved. Three problem domains are treated by TWOHEX. The whole core domain is a 60 0 parallelogram with vacuum boundary conditions on each face. The third core domain is a 120 0 parallelogram with two vacuum and two rotational boundary conditions. The sixth core domain is a 60 0 parallelogram with two vacuum and two rotational boundary conditions. General anisotropic scattering is allowed and an anisotropic inhomogeneous source may be input as cell averages
Energy Technology Data Exchange (ETDEWEB)
Prinja, A.K.
1998-09-01
In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton`s method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria {epsilon} is set to be 10{sup {minus}9} based on the fact that lower value of {epsilon} does not alter the solution significantly. Correspondingly, the number of Newton`s iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton`s method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are
International Nuclear Information System (INIS)
Prinja, A.K.
1998-01-01
In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton's method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria ε is set to be 10 -9 based on the fact that lower value of ε does not alter the solution significantly. Correspondingly, the number of Newton's iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton's method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are relatively smooth as a
Three-dimensional reconstruction and visualization system for medical images
International Nuclear Information System (INIS)
Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.
1982-01-01
A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system
Multisoliton formula for completely integrable two-dimensional systems
International Nuclear Information System (INIS)
Chudnovsky, D.V.; Chudnovsky, G.V.
1979-01-01
For general two-dimensional completely integrable systems, the exact formulae for multisoliton type solutions are given. The formulae are obtained algebrically from solutions of two linear partial differential equations
Strong chaos in one-dimensional quantum system
International Nuclear Information System (INIS)
Yang, C.-D.; Wei, C.-H.
2008-01-01
According to the Poincare-Bendixson theorem, a minimum of three autonomous equations is required to exhibit deterministic chaos. Because a one-dimensional quantum system is described by only two autonomous equations using de Broglie-Bohm's trajectory interpretation, chaos in one-dimensional quantum systems has long been considered impossible. We will prove in this paper that chaos phenomenon does exist in one-dimensional quantum systems, if the domain of quantum motions is extended to complex space by noting that the quantum world is actually characterized by a four-dimensional complex spacetime according to the E (∞) theory. Furthermore, we point out that the interaction between the real and imaginary parts of complex trajectories produces a new chaos phenomenon unique to quantum systems, called strong chaos, which describes the situation that quantum trajectories may emerge and diverge spontaneously without any perturbation in the initial position
International Nuclear Information System (INIS)
Patterson, J.A.; Fong, M.; Koehler, G.W.; Low, W.; Purgalis, P.; Wells, R.P.
1983-01-01
The Neutral Beam Engineering Test Facility (NBETF) at the Lawrence Berkeley Laboratory (LBL) is a National Test Facility used to develop long pulse Neutral Beam Sources. The Facility will test sources up to 120 keV, 50 A, with 30 s beam-on times with a 10% duty factor. For this application, an actively cooled beam dump is required and one has been constructed capable of dissipating a wide range of power density profiles. The flexibility of the design is achieved by utilizing a standard modular panel design which is incorporated into a moveable support structure comprised of eight separately controllable manipulator assemblies. The thermal hydraulic design of the panels permits the dissipation of 2 kW/cm 2 anywhere on the panel surface. The cooling water requirements of the actively cooled dump system are provided by the closed loop Primary High Pressure Cooling Water System. To minimize the operating costs of continuously running this high power system, a variable speed hydraulic drive is used for the main pump. During beam pulses, the pump rotates at high speed, then cycles to low speed upon completion of the beam shot. A unique neutralizer design has been installed into the NBETF beamline. This is a gun-drilled moveable brazed assembly which provides continuous armoring of the beamline near the source. The unit penetrates the source mounting valve during operation and retracts to permit the valve to close as needed. The beamline also has an inertially cooled duct calorimeter assembly. This assembly is a moveable hinged matrix of copper plates that can be used as a beam stop up to pulse lengths of 50 ms. The beamline is also equipped with many beam scraper plates of differing detail design and dissipation capabilities
International Nuclear Information System (INIS)
Veshchev, E. A.; Ozaki, T.; Goncharov, P. R.; Sudo, S.
2006-01-01
A new multichannel diagnostic for fast ion distribution studies has been developed and successfully tested on the Large Helical Device (LHD) in different plasma heating conditions. The diagnostic is based on a linear array AXUV detector consisting of 20 segments, charge sensitive preamplifiers, and a set of pulse height analysis channels. The main advantage of this system is the possibility to make time, energy, and angle-resolved measurements of charge exchange neutral particles in a single plasma discharge. This feature makes the new diagnostic a very helpful and powerful tool intended to contribute to the understanding of fast ion behavior in a complex helical plasma geometry like the one of LHD
Directory of Open Access Journals (Sweden)
Heli Hu
2014-01-01
Full Text Available The design of the dynamic output feedback H∞ control for uncertain interconnected systems of neutral type is investigated. In the framework of Lyapunov stability theory, a mathematical technique dealing with the nonlinearity on certain matrix variables is developed to obtain the solvability conditions for the anticipated controller. Based on the corresponding LMIs, the anticipated gains for dynamic output feedback can be achieved by solving some algebraic equations. Also, the norm of the transfer function from the disturbance input to the controlled output is less than the given index. A numerical example and the simulation results are given to show the effectiveness of the proposed method.
Energy Technology Data Exchange (ETDEWEB)
Hemsworth, R S [ITER Joint Central Team, Naka, Ibaraki (Japan)
1997-03-01
This paper describes the Neutral Beam Injection system which is presently being designed for the International Tokamak Experimental Reactor, ITER, in Europe Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D{sup 0} to the ITER plasma for a pulse length of >1000 s. Each injectors uses a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D{sup -}. This will be neutralized by collisions with D{sub 2} in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. ITER is scheduled to produce its first plasma at the beginning of 2008, and the planning of the R and D, construction and installation foresees the neutral injection system being available from the start of ITER operations. (author)
Nonfragile Guaranteed Cost Control and Optimization for Interconnected Systems of Neutral Type
Directory of Open Access Journals (Sweden)
Heli Hu
2013-01-01
Full Text Available The design and optimization problems of the nonfragile guaranteed cost control are investigated for a class of interconnected systems of neutral type. A novel scheme, viewing the interconnections with time-varying delays as effective information but not disturbances, is developed to decrease the conservatism. Many techniques on decomposing and magnifying the matrices are utilized to obtain the guaranteed cost of the considered system. Also, an algorithm is proposed to solve the nonlinear problem of the interconnected matrices. Based on this algorithm, the minimization of the guaranteed cost of the considered system is obtained by optimization. Further, the state feedback control is extended to the case in which the underlying system is dependent on uncertain parameters. Finally, two numerical examples are given to illustrate the proposed method, and some comparisons are made to show the advantages of the schemes of dealing with the interconnections.
Analysis of chaos in high-dimensional wind power system.
Wang, Cong; Zhang, Hongli; Fan, Wenhui; Ma, Ping
2018-01-01
A comprehensive analysis on the chaos of a high-dimensional wind power system is performed in this study. A high-dimensional wind power system is more complex than most power systems. An 11-dimensional wind power system proposed by Huang, which has not been analyzed in previous studies, is investigated. When the systems are affected by external disturbances including single parameter and periodic disturbance, or its parameters changed, chaotic dynamics of the wind power system is analyzed and chaotic parameters ranges are obtained. Chaos existence is confirmed by calculation and analysis of all state variables' Lyapunov exponents and the state variable sequence diagram. Theoretical analysis and numerical simulations show that the wind power system chaos will occur when parameter variations and external disturbances change to a certain degree.
Control system for 5 MW neutral beam ion source for SST1
Patel, G. B.; Onali, Raja; Sharma, Vivek; Suresh, S.; Tripathi, V.; Bandyopadhyay, M.; Singh, N. P.; Thakkar, Dipal; Gupta, L. N.; Singh, M. J.; Patel, P. J.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.
2006-01-01
This article describes the control system for a 5MW ion source of the NBI (neutral beam injector) for steady-state superconducting tokamak-1 (SST-1). The system uses both hardware and software solutions. It comprises a DAS (data acquisition system) and a control system. The DAS is used to read the voltage and current signals from eight filament heater power supplies and 24 discharge power supplies. The control system is used to adjust the filament heater current in order to achieve an effective control on the discharge current in the plasma box. The system consists of a VME (Verse Module Eurocard) system and C application program running on a VxWorks™ real-time operating system. A PID (proportional, integral, and differential) algorithm is used to control the filament heater current. Experiments using this system have shown that the discharge current can be controlled within 1% accuracy for a PID loop time of 20ms. Response of the control system to the pressure variation of the gas in the chamber has also been studied and compared with the results obtained from those of an uncontrolled system. The present approach increases the flexibility of the control system. It not only eases the control of the plasma but also allows an easy changeover to various operation scenarios.
Design Features of the Neutral Particle Diagnostic System for the ITER Tokamak
Petrov, S. Ya.; Afanasyev, V. I.; Melnik, A. D.; Mironov, M. I.; Navolotsky, A. S.; Nesenevich, V. G.; Petrov, M. P.; Chernyshev, F. V.; Kedrov, I. V.; Kuzmin, E. G.; Lyublin, B. V.; Kozlovski, S. S.; Mokeev, A. N.
2017-12-01
The control of the deuterium-tritium (DT) fuel isotopic ratio has to ensure the best performance of the ITER thermonuclear fusion reactor. The diagnostic system described in this paper allows the measurement of this ratio analyzing the hydrogen isotope fluxes (performing neutral particle analysis (NPA)). The development and supply of the NPA diagnostics for ITER was delegated to the Russian Federation. The diagnostics is being developed at the Ioffe Institute. The system consists of two analyzers, viz., LENPA (Low Energy Neutral Particle Analyzer) with 10-200 keV energy range and HENPA (High Energy Neutral Particle Analyzer) with 0.1-4.0MeV energy range. Simultaneous operation of both analyzers in different energy ranges enables researchers to measure the DT fuel ratio both in the central burning plasma (thermonuclear burn zone) and at the edge as well. When developing the diagnostic complex, it was necessary to account for the impact of several factors: high levels of neutron and gamma radiation, the direct vacuum connection to the ITER vessel, implying high tritium containment, strict requirements on reliability of all units and mechanisms, and the limited space available for accommodation of the diagnostic hardware at the ITER tokamak. The paper describes the design of the diagnostic complex and the engineering solutions that make it possible to conduct measurements under tokamak reactor conditions. The proposed engineering solutions provide a safe—with respect to thermal and mechanical loads—common vacuum channel for hydrogen isotope atoms to pass to the analyzers; ensure efficient shielding of the analyzers from the ITER stray magnetic field (up to 1 kG); provide the remote control of the NPA diagnostic complex, in particular, connection/disconnection of the NPA vacuum beamline from the ITER vessel; meet the ITER radiation safety requirements; and ensure measurements of the fuel isotopic ratio under high levels of neutron and gamma radiation.
Implementation of three dimensional treatment planning system for external radiotherapy
International Nuclear Information System (INIS)
Major, Tibor; Kurup, P.G.G.; Stumpf, Janos
1997-01-01
A three dimensional (3D) treatment planning system was installed at Apollo Cancer Hospital, Chennai, India in 1995. This paper gives a short description of the system including hardware components, calculation algorithm, measured data requirements and specific three dimensional features. The concept and the structure of the system are shortly described. The first impressions along with critical opinions and the experiences are gained during the data acquisition are mentioned. Some improvements in the user interface are suggested. It is emphasized that although a 3D system offers more detailed and accurate dose distributions compared to a 2D system, it also introduces a greatly increased workload for the planning staff. (author)
The theory of critical phenomena in two-dimensional systems
International Nuclear Information System (INIS)
Olvera de la C, M.
1981-01-01
An exposition of the theory of critical phenomena in two-dimensional physical systems is presented. The first six chapters deal with the mean field theory of critical phenomena, scale invariance of the thermodynamic functions, Kadanoff's spin block construction, Wilson's renormalization group treatment of critical phenomena in configuration space, and the two-dimensional Ising model on a triangular lattice. The second part of this work is made of four chapters devoted to the application of the ideas expounded in the first part to the discussion of critical phenomena in superfluid films, two-dimensional crystals and the two-dimensional XY model of magnetic systems. Chapters seven to ten are devoted to the following subjects: analysis of long range order in one, two, and three-dimensional physical systems. Topological defects in the XY model, in superfluid films and in two-dimensional crystals. The Thouless-Kosterlitz iterated mean field theory of the dipole gas. The renormalization group treatment of the XY model, superfluid films and two-dimensional crystal. (author)
Nica, Emilian M.; Franz, Marcel
2018-02-01
Motivated by recent work on strain-induced pseudomagnetic fields in Dirac and Weyl semimetals, we analyze the possibility of analogous fields in two-dimensional nodal superconductors. We consider the prototypical case of a d -wave superconductor, a representative of the cuprate family, and find that the presence of weak, spatially varying strain leads to pseudomagnetic fields and Landau quantization of Bogoliubov quasiparticles in the low-energy sector. A similar effect is induced by the presence of generic, weak doping gradients. In contrast to genuine magnetic fields in superconductors, the strain- and doping-gradient-induced pseudomagnetic fields couple in a way that preserves time-reversal symmetry and is not subject to the screening associated with the Meissner effect. These effects can be probed by tuning weak applied supercurrents which lead to shifts in the energies of the Landau levels and hence to quantum oscillations in thermodynamic and transport quantities.
PREFACE: Dynamics of low-dimensional systems Dynamics of low-dimensional systems
Bernasconi, M.; Miret-Artés, S.; Toennies, J. P.
2012-03-01
With the development of techniques for high-resolution inelastic helium atom scattering (HAS), electron scattering (EELS) and neutron spin echo spectroscopy, it has become possible, within approximately the last thirty years, to measure the dispersion curves of surface phonons in insulators, semiconductors and metals. In recent years, the advent of new experimental techniques such as 3He spin-echo spectroscopy, scanning inelastic electron tunnel spectroscopy, inelastic x-ray scattering spectroscopy and inelastic photoemission have extended surface phonon spectroscopy to a variety of systems. These include ultra-thin metal films, adsorbates at surface and elementary processes where surface phonons play an important role. Other important directions have been actively pursued in the past decade: the dynamics of stepped surfaces and clusters grown on metal surfaces, due to their relevance in many dynamical and chemical processes at surfaces, including heterogeneous catalysis; clusters; diffusion etc. The role of surface effects in these processes has been conjectured since the early days of surface dynamics, although only now is the availability of ab initio approaches providing those conjectures with a microscopic basis. Last but not least, the investigation of non-adiabatic effects, originating for instance from the hybridization (avoided crossing) of the surface phonons branches with the quasi 1D electron-hole excitation branch, is also a challenging new direction. Furthermore, other elementary oscillations such as surface plasmons are being actively investigated. The aforementioned experimental breakthroughs have been accompanied by advances in the theoretical study of atom-surface interaction. In particular, in the past decade first principles calculations based on density functional perturbation theory have boosted the theoretical study of the dynamics of low-dimensional systems. Phonon dispersion relations of clean surfaces, the dynamics of adsorbates, and the
Criticality in the fabrication of ion extraction system for SST-1 neutral beam injector
International Nuclear Information System (INIS)
Jana, M.R.; Mattoo, S.K.
2008-01-01
For the heating of plasma in steady-state superconducting tokamak (SST-1) (Y.C. Saxena, SST-1 Team, Present status of the SST-1 project, Nucl. Fusion 40 (2000) 1069-1082; D. Bora, SST-1 Team, Test results on systems developed for the SST-1 tokamak, Nucl. Fusion 43 (2003) 1748-1758), a neutral beam injector is provided to raise the ion temperature to ∼1 keV. This injector has a capability of injecting hydrogen beam with the power of 0.5 MW at 30 keV. For the upgrade of SST-1, power of 1.7 MW at 55 KeV is required. Further, beam power is to be provided for a pulse length of 1000S. We have designed a neutral beam injector (S.K. Mattoo, A.K. Chakraborty, U.K. Baruah, P.K. Jayakumar, M. Bandyopadhyay, N. Bisai, Ch. Chakrapani, M.R. Jana, R. Onali, V. Prahlad, P.J. Patel, G.B. Patel, B. Prajapati, N.V.M. Rao, S. Rambabu, C. Rotti, S.K. Sharma, S. Shah, V. Sharma, M.J. Singh, Engineering design of the steady-state neutral beam injector for SST-1, Fusion Eng. Des. 56 (2001) 685-691; A.K. Chakraborty, N. Bisai, M.R. Jana, P.K. Jayakumar, U.K. Baruah, P.J. Patel, K. Rajasekar, S.K. Mattoo, Neutral beam injector for steady-state superconducting tokamak, Fusion Technol. (1996) 657-660; P.K. Jayakumar, M.R. Jana, N. Bisai, M. Bajpai, N.P. Singh, U.K. Baruah, A.K. Chakraborty, M. Bandyopadhyay, C. Chrakrapani, D. Patel, G.B. Patel, P. Patel, V. Prahlad, N.V.M. Rao, C. Rotti, V. Sreedhar, S.K. Mattoo, Engineering issues of a 1000S neutral beam ion source, Fusion Technol. 1 (1998) 419-422) satisfying the requirements for both SST-1 and its upgrade. Since intense power is to be transported to SST-1 situated at a distance of several meters from the ion source, the optical quality of the beam becomes a primary concern. This in turn, is determined by the uniformity of the ion source plasma and the extractor geometry. To obtain the desired optical quality of the beam, stringent tolerances are to be met during the fabrication of ion extractor system. SST-1 neutral beam injector is
One dimensional systems with singular perturbations
International Nuclear Information System (INIS)
Alvarez, J J; Gadella, M; Nieto, L M; Glasser, L M; Lara, L P
2011-01-01
This paper discusses some one dimensional quantum models with singular perturbations. Eventually, a mass discontinuity is added at the points that support the singular perturbations. The simplest model includes an attractive singular potential with a mass jump both located at the origin. We study the form of the only bound state. Another model exhibits a hard core at the origin plus one or more repulsive deltas with mass jumps at the points supporting these deltas. We study the location and the multiplicity of these resonances for the case of one or two deltas and settle the basis for a generalization. Finally, we consider the harmonic oscillator and the infinite square well plus a singular potential at the origin. We see how the energy of bound states is affected by the singular perturbation.
Application of the OPTIMUS Code to the Neutral Beam Injection System of TJ-II
International Nuclear Information System (INIS)
Fuentes, C.; Liniers, M.; Guasp, J.
1998-01-01
The different losses processes affecting a neutral beam since is born into the ions source until is coming into the fusion machine, are dependent of the residual gas pressure distribution inside injector. The OPTIMUS code analyzes that losses and calculates the pressure distribution inside one injector with specific geometry. The adaptation of injector to TJ-II has not required important design changes, only the operating range of the gas flow and the pumping speed have modified. The calculations show that the required gas flows for the optimal operation of the system ned an independent pumping system for the calorimeter box with a pumping speed of 1200001/s. The system efficiency is not affected by an hypothetical beaming effect and it is found also that with a proper conditioning of the injector walls, so that the absorption coefficients do not surpass excessively the unity value, the injector operation remains optimal. (Author) 8 refs
International Nuclear Information System (INIS)
Gravil, B.; Henry, D.; Cordier, J.J.; Hemsworth, R.; Van Houtte, D.
2004-01-01
The ITER neutral beam heating and current drive system is to be equipped with a cryosorption cryopump made up of 12 panels connected in parallel, refrigerated by 4.5 K 0.4 MPa supercritical helium. The pump is submitted to a non homogeneous flux of H 2 or D 2 molecules, and the absorbed flux varies from 3 Pa.m -3 .s -1 to 35 Pa.m -3 .s -1 . In the frame of the 'ITER first injector and test facility CSU-EFDA task' (TW3-THHN-IITF1), the ITER reference cryo-system and cryo-plant designs have been assessed and compared to optimised designs devoted to the Neutral Beam Test Facility (NBTF). The 4.5 K cryo-panel, which has a mass of about 1000 kg, must be periodically regenerated up to 90 K and occasionally to 470 K. The cool-down time after regeneration depends strongly on the refrigeration capacity. Fast regeneration and cool-down of the cryo-panels are not considered a priority for the test facility operation, and an analysis of the consequences of a limited cold power refrigerator on the cooling down time has been carried out and will be discussed. This paper presents a preliminary evaluation of the NBTF cryo-plant and the associated process flow diagram. (authors)
SYSTEM DESIGN AND PERFORMANCE FOR THE RECENT DIII-D NEUTRAL BEAM COMPUTER UPGRADE
International Nuclear Information System (INIS)
PHILLIPS, J.C; PENAFLOR, B.G; PHAM, N.Q; PIGLOWSKI, D.A.
2004-03-01
OAK-B135 This operating year marks an upgrade to the computer system charged with control and data acquisition for neutral beam injection system's heating at the DIII-D National Fusion Facility, funded by the US Department of Energy and operated by General Atomics (GA). This upgrade represents the third and latest major revision to a system which has been in service over twenty years. The first control and data acquisition computers were four 16 bit mini computers running a proprietary operating system. Each of the four controlled two ion source over dedicated CAMAC highway. In a 1995 upgrade, the system evolved to be two 32 bit Motorola mini-computers running a version of UNIX. Each computer controlled four ion sources with two CAMAC highways per CPU. This latest upgrade builds on this same logical organization, but makes significant advances in cost, maintainability, and the degree to which the system is open to future modification. The new control and data acquisition system is formed of two 2 GHz Intel Pentium 4 based PC's, running the LINUX operating system. Each PC drives two CAMAC serial highways using a combination of Kinetic Systems PCI standard CAMAC Hardware Drivers and a low-level software driver written in-house expressly for this device. This paper discusses the overall system design and implementation detail, describing actual operating experience for the initial six months of operation
Shirani, Sahar; Hellweger, Ferdi L
2017-08-01
Molecular observations reveal substantial biogeographic patterns of cyanobacteria within systems of connected lakes. An important question is the relative role of environmental selection and neutral processes in the biogeography of these systems. Here, we quantify the effect of genetic drift and dispersal limitation by simulating individual cyanobacteria cells using an agent-based model (ABM). In the model, cells grow (divide), die, and migrate between lakes. Each cell has a full genome that is subject to neutral mutation (i.e., the growth rate is independent of the genome). The model is verified by simulating simplified lake systems, for which theoretical solutions are available. Then, it is used to simulate the biogeography of the cyanobacterium Microcystis aeruginosa in a number of real systems, including the Great Lakes, Klamath River, Yahara River, and Chattahoochee River. Model output is analyzed using standard bioinformatics tools (BLAST, MAFFT). The emergent patterns of nucleotide divergence between lakes are dynamic, including gradual increases due to accumulation of mutations and abrupt changes due to population takeovers by migrant cells (coalescence events). The model predicted nucleotide divergence is heterogeneous within systems, and for weakly connected lakes, it can be substantial. For example, Lakes Superior and Michigan are predicted to have an average genomic nucleotide divergence of 8200 bp or 0.14%. The divergence between more strongly connected lakes is much lower. Our results provide a quantitative baseline for future biogeography studies. They show that dispersal limitation can be an important factor in microbe biogeography, which is contrary to the common belief, and could affect how a system responds to environmental change.
Impurity states in two - and three-dimensional disordered systems
International Nuclear Information System (INIS)
Silva, A.F. da; Fabbri, M.
1984-01-01
We investigate the microscopic structure of the impurity states in two-and three-dimensional (2D and 3d) disordered systems. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (Author) [pt
Problems of high temperature superconductivity in three-dimensional systems
Energy Technology Data Exchange (ETDEWEB)
Geilikman, B T
1973-01-01
A review is given of more recent papers on this subject. These papers have dealt mainly with two-dimensional systems. The present paper extends the treatment to three-dimensional systems, under the following headings: systems with collective electrons of one group and localized electrons of another group (compounds of metals with non-metals-dielectrics, organic substances, undoped semiconductors, molecular crystals); experimental investigations of superconducting compounds of metals with organic compounds, dielectrics, semiconductors, and semi-metals; and systems with two or more groups of collective electrons. Mechanics are considered and models are derived. 86 references.
Model space dimensionalities for multiparticle fermion systems
International Nuclear Information System (INIS)
Draayer, J.P.; Valdes, H.T.
1985-01-01
A menu driven program for determining the dimensionalities of fixed-(J) [or (J,T)] model spaces built by distributing identical fermions (electrons, neutrons, protons) or two distinguihable fermion types (neutron-proton and isospin formalisms) among any mixture of positive and negative parity spherical orbitals is presented. The algorithm, built around the elementary difference formula d(J)=d(M=J)-d(M=J+1), takes full advantage of M->-M and particle-hole symmetries. A 96 K version of the program suffices for as compilated a case as d[(+1/2, +3/2, + 5/2, + 7/2-11/2)sup(n-26)J=2 + ,T=7]=210,442,716,722 found in the 0hω valence space of 56 126 Ba 70 . The program calculates the total fixed-(Jsup(π)) or fixed-(Jsup(π),T) dimensionality of a model space generated by distributing a specified number of fermions among a set of input positive and negative parity (π) spherical (j) orbitals. The user is queried at each step to select among various options: 1. formalism - identical particle, neutron-proton, isospin; 2. orbits -bumber, +/-2*J of all orbits; 3. limits -minimum/maximum number of particles of each parity; 4. specifics - number of particles, +/-2*J (total), 2*T; 5. continue - same orbit structure, new case quit. Though designed for nuclear applications (jj-coupling), the program can be used in the atomic case (LS-coupling) so long as half integer spin values (j=l+-1/2) are input for the valnce orbitals. Mutiple occurrences of a given j value are properly taken into account. A minor extension provides labelling information for a generalized seniority classification scheme. The program logic is an adaption of methods used in statistical spectroscopy to evaluate configuration averages. Indeed, the need for fixed symmetry leve densities in spectral distribution theory motivated this work. The methods extend to other group structures where there are M-like additive quantum labels. (orig.)
A study of low-dimensional inhomogeneous systems
International Nuclear Information System (INIS)
Arredondo Leon, Yesenia
2009-01-01
While the properties of homogeneous one-dimensional systems, even with disorder, are relatively well-understood, very little is known about the properties of strongly interacting inhomogeneous systems. Their high-energy physics is determined by the underlying chemistry which, in the atomic scale, introduces Coulomb correlations and local potentials. On the other hand, at large length scales, the physics has to be described by the Tomonaga-Luttinger liquid (TLL) model. In order to establish a connection between the low-energy TLL and the quasi-one-dimensional systems synthesized in the laboratory, we investigate the density-density correlation function in inhomogeneous one-dimensional systems in the asymptotic region. To investigate homogeneous as well as inhomogeneous systems, we use the density-matrix renormalization group (DMRG) method. We present results for ground state properties, such as the density-density correlation function and the parameter K c , which characterizes its decay at large distances. (orig.)
A study of low-dimensional inhomogeneous systems
Energy Technology Data Exchange (ETDEWEB)
Arredondo Leon, Yesenia
2009-01-15
While the properties of homogeneous one-dimensional systems, even with disorder, are relatively well-understood, very little is known about the properties of strongly interacting inhomogeneous systems. Their high-energy physics is determined by the underlying chemistry which, in the atomic scale, introduces Coulomb correlations and local potentials. On the other hand, at large length scales, the physics has to be described by the Tomonaga-Luttinger liquid (TLL) model. In order to establish a connection between the low-energy TLL and the quasi-one-dimensional systems synthesized in the laboratory, we investigate the density-density correlation function in inhomogeneous one-dimensional systems in the asymptotic region. To investigate homogeneous as well as inhomogeneous systems, we use the density-matrix renormalization group (DMRG) method. We present results for ground state properties, such as the density-density correlation function and the parameter K{sub c}, which characterizes its decay at large distances. (orig.)
Low-dimensional chaos in a hydrodynamic system
International Nuclear Information System (INIS)
Brandstater, A.; Swift, J.; Swinney, H.L.; Wolf, A.; Farmer, J.D.; Jen, E.; Crutchfield, J.P.
1983-01-01
Evidence is presented for low-dimensional strange attractors in Couette-Taylor flow data. Computations of the largest Lyapunov exponent and metric entropy show that the system displays sensitive dependence on initial conditions. Although the phase space is very high dimensional, analysis of experimental data shows that motion is restricted to an attractor of dimension less than 5 for Reynolds numbers up to 30% above the onset of chaos. The Lyapunov exponent, entropy, and dimension all generally increase with Reynolds number
One dimensional Bosons: From Condensed Matter Systems to Ultracold Gases
Cazalilla, M. A.; Citro, R.; Giamarchi, T.; Orignac, E.; Rigol, M.
2011-01-01
The physics of one-dimensional interacting bosonic systems is reviewed. Beginning with results from exactly solvable models and computational approaches, the concept of bosonic Tomonaga-Luttinger liquids relevant for one-dimensional Bose fluids is introduced, and compared with Bose-Einstein condensates existing in dimensions higher than one. The effects of various perturbations on the Tomonaga-Luttinger liquid state are discussed as well as extensions to multicomponent and out of equilibrium ...
Stability and Hopf Bifurcation of a Reaction-Diffusion Neutral Neuron System with Time Delay
Dong, Tao; Xia, Linmao
2017-12-01
In this paper, a type of reaction-diffusion neutral neuron system with time delay under homogeneous Neumann boundary conditions is considered. By constructing a basis of phase space based on the eigenvectors of the corresponding Laplace operator, the characteristic equation of this system is obtained. Then, by selecting time delay and self-feedback strength as the bifurcating parameters respectively, the dynamic behaviors including local stability and Hopf bifurcation near the zero equilibrium point are investigated when the time delay and self-feedback strength vary. Furthermore, the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions are obtained by using the normal form and the center manifold theorem for the corresponding partial differential equation. Finally, two simulation examples are given to verify the theory.
TFTR neutral beam D-T gas injection system operational experiences of the first two years
International Nuclear Information System (INIS)
Oldaker, M.E.; Lawson, J.E.; Stevenson, T.N.; Kamperschroer, J.H.
1995-01-01
The TFTR Neutral Beam Tritium Gas Injection System (TGIS) has successfully performed tritium operations since December 1993. TGIS operation has been reliable, with no leaks to the secondary containment to date. Notable operational problems include throughput leaks on fill, exit and piezoelectric valves. Repair of a TGIS requires replacement of the assembly, involving TFTR downtime and extensive purging, since the TGIS assembly is highly contaminated with residual tritium, and is located within secondary containment. Modifications to improve reliability and operating range include adjustable reverse bias voltage to the piezoelectric valves, timing and error calculation changes to tune the PLC and hardwired timing control, and exercising piezoelectric valves without actually pulsing gas prior to use after extended inactivity. A pressure sensor failure required the development of an open loop piezoelectric valve drive control scheme, using a simple voltage ramp to partially compensate for declining plenum pressure. Replacement of TGIS's have been performed, maintaining twelve system tritium capability as part of scheduled project maintenance activity
International Nuclear Information System (INIS)
Tyagi, Himanshu; Soni, Jignesh; Yadav, Ratnakar; Bandyopadhyay, Mainak; Rotti, Chandramouli; Gahlaut, Agrajit; Joshi, Jaydeep; Parmar, Deepak; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun
2016-01-01
Highlights: • Indian Test Facility being built to characterize DNB for ITER delivery. • Interlock system required to safeguard the investment incurred in building the facility and protecting ITER deliverable components. • Interlock levels upto 3IL-3 identified. • Safety instrumented system for occupational safety being designed. Safety I&C functions of SIL-2 identified. • The systems are based on ITER PIS and PSS design guidelines. - Abstract: Indian Test Facility (INTF) is being built in Institute For Plasma Research to characterize Diagnostic Neutral Beam in co-operation with ITER Organization. INTF is a complex system which consists of several plant systems like beam source, gas feed, vacuum, cryogenics, high voltage power supplies, high power RF generators, mechanical systems and diagnostics systems. Out of these, several INTF components are ITER deliverable, that is, beam source, beam line components and power supplies. To ensure successful operation of INTF involving integrated operation of all the constituent plant systems a matured Data Acquisition and Control System (DACS) is required. The INTF DACS is based on CODAC platform following on PCDH (Plant Control Design Handbook) guidelines. The experimental phases involve application of HV power supplies (100 KV) and High RF power (∼800 KW) which will produce energetic beam of maximum power 6MW within the facility for longer durations. Hence the entire facility will be exposed tohigh heat fluxes and RF radiations. To ensure investment protection and to provide occupational safety for working personnel a matured Safety and Interlock system is required for INTF. The Safety and Interlock systems are high-reliability I&C systems devoted completely to the specific functions. These systems will be separate from the conventional DACS of INTF which will handle the conventional control and acquisition functions. Both, the Safety and Interlock systems are based on IEC 61511 and IEC 61508 standards as
Energy Technology Data Exchange (ETDEWEB)
Tyagi, Himanshu, E-mail: htyagi@iter-india.org [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Soni, Jignesh [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Yadav, Ratnakar; Bandyopadhyay, Mainak; Rotti, Chandramouli [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Gahlaut, Agrajit [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Joshi, Jaydeep; Parmar, Deepak [ITER-India, Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India); Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun [Institute For Plasma Research, Bhat, Gandhinagar, Gujarat (India)
2016-11-15
Highlights: • Indian Test Facility being built to characterize DNB for ITER delivery. • Interlock system required to safeguard the investment incurred in building the facility and protecting ITER deliverable components. • Interlock levels upto 3IL-3 identified. • Safety instrumented system for occupational safety being designed. Safety I&C functions of SIL-2 identified. • The systems are based on ITER PIS and PSS design guidelines. - Abstract: Indian Test Facility (INTF) is being built in Institute For Plasma Research to characterize Diagnostic Neutral Beam in co-operation with ITER Organization. INTF is a complex system which consists of several plant systems like beam source, gas feed, vacuum, cryogenics, high voltage power supplies, high power RF generators, mechanical systems and diagnostics systems. Out of these, several INTF components are ITER deliverable, that is, beam source, beam line components and power supplies. To ensure successful operation of INTF involving integrated operation of all the constituent plant systems a matured Data Acquisition and Control System (DACS) is required. The INTF DACS is based on CODAC platform following on PCDH (Plant Control Design Handbook) guidelines. The experimental phases involve application of HV power supplies (100 KV) and High RF power (∼800 KW) which will produce energetic beam of maximum power 6MW within the facility for longer durations. Hence the entire facility will be exposed tohigh heat fluxes and RF radiations. To ensure investment protection and to provide occupational safety for working personnel a matured Safety and Interlock system is required for INTF. The Safety and Interlock systems are high-reliability I&C systems devoted completely to the specific functions. These systems will be separate from the conventional DACS of INTF which will handle the conventional control and acquisition functions. Both, the Safety and Interlock systems are based on IEC 61511 and IEC 61508 standards as
OBSERVING LYAPUNOV EXPONENTS OF INFINITE-DIMENSIONAL DYNAMICAL SYSTEMS.
Ott, William; Rivas, Mauricio A; West, James
2015-12-01
Can Lyapunov exponents of infinite-dimensional dynamical systems be observed by projecting the dynamics into ℝ N using a 'typical' nonlinear projection map? We answer this question affirmatively by developing embedding theorems for compact invariant sets associated with C 1 maps on Hilbert spaces. Examples of such discrete-time dynamical systems include time- T maps and Poincaré return maps generated by the solution semigroups of evolution partial differential equations. We make every effort to place hypotheses on the projected dynamics rather than on the underlying infinite-dimensional dynamical system. In so doing, we adopt an empirical approach and formulate checkable conditions under which a Lyapunov exponent computed from experimental data will be a Lyapunov exponent of the infinite-dimensional dynamical system under study (provided the nonlinear projection map producing the data is typical in the sense of prevalence).
Dynamical class of a two-dimensional plasmonic Dirac system.
Silva, Érica de Mello
2015-10-01
A current goal in plasmonic science and technology is to figure out how to manage the relaxational dynamics of surface plasmons in graphene since its damping constitutes a hinder for the realization of graphene-based plasmonic devices. In this sense we believe it might be of interest to enlarge the knowledge on the dynamical class of two-dimensional plasmonic Dirac systems. According to the recurrence relations method, different systems are said to be dynamically equivalent if they have identical relaxation functions at all times, and such commonality may lead to deep connections between seemingly unrelated physical systems. We employ the recurrence relations approach to obtain relaxation and memory functions of density fluctuations and show that a two-dimensional plasmonic Dirac system at long wavelength and zero temperature belongs to the same dynamical class of standard two-dimensional electron gas and classical harmonic oscillator chain with an impurity mass.
Electronic states in systems of reduced dimensionality
International Nuclear Information System (INIS)
Ulloa, S.E.
1992-01-01
This report briefly discusses the following research: magnetically modulated systems, inelastic magnetotunneling, ballistic transport review, screening in reduced dimensions, raman and electron energy loss spectroscopy; and ballistic quantum interference effects. (LSP)
Real-time control and data-acquisition system for high-energy neutral-beam injectors
International Nuclear Information System (INIS)
Glad, A.S.; Jacobson, V.
1981-12-01
The need for a real-time control system and a data acquisition, processing and archiving system operating in parallel on the same computer became a requirement on General Atomic's Doublet III fusion energy project with the addition of high energy neutral beam injectors. The data acquisition processing and archiving system is driven from external events and is sequenced through each experimental shot utilizing ModComp's intertask message service. This system processes, archives and displays on operator console CRTs all physics diagnostic data related to the neutral beam injectores such as temperature, beam alignment, etc. The real-time control system is data base driven and provides periodic monitoring and control of the numerous dynamic subsystems of the neutral beam injectors such as power supplies, timing, water cooling, etc
Port Hamiltonian Formulation of Infinite Dimensional Systems I. Modeling
Macchelli, Alessandro; Schaft, Arjan J. van der; Melchiorri, Claudio
2004-01-01
In this paper, some new results concerning the modeling of distributed parameter systems in port Hamiltonian form are presented. The classical finite dimensional port Hamiltonian formulation of a dynamical system is generalized in order to cope with the distributed parameter and multi-variable case.
Lyapunov equation for infinite-dimensional discrete bilinear systems
International Nuclear Information System (INIS)
Costa, O.L.V.; Kubrusly, C.S.
1991-03-01
Mean-square stability for discrete systems requires that uniform convergence is preserved between input and state correlation sequences. Such a convergence preserving property holds for an infinite-dimensional bilinear system if and only if the associate Lyapunov equation has a unique strictly positive solution. (author)
Experimental searches for CP and CPT symmetries violation in the neutral kaons system
International Nuclear Information System (INIS)
Debu, P.
1996-01-01
The aim of this lecture is to give an overview of the experiments devoted to the study and research of CP, T and CPT symmetries invariance violations in the system of neutral K mesons. The discovery of K mesons has provided crucial informations for the elaboration of the standard model. However, the observation of CP violation has remained confined to the K system. The origin of the observed CP violation remains hypothetic. Its origin could be a complex phase in the mixing matrix of quarks. In the standard model of electroweak interactions, several evidences of the CP violation exist: the observed K neutral mesons (K L and K S ) are not proper states of CP and are due to CP violation in the K 0 - anti-K 0 mixture. On the other hand, the model predicts also a CP violation in decay amplitudes, named direct CP violation. Important experiments have been carried out for its demonstration. The K system is also the most precise test for CPT invariance. A description of the experiments in progress developed to improve the precision of these tests is given. The plan of the lecture is the following: after a recall of K 0 - anti-K 0 phenomenology, some important steps in the CP violation study are described. Then, the regeneration phenomenon is briefly described and two of the most recent measurements of the direct CP violation parameter are analysed. Finally, the CPT invariance tests are described with their parameters and the measurements in progress. A review of the principal results is given in conclusion with their improvements expected in a near future. (J.S.). 71 refs., 4 figs., 4 tabs
Computer system for the beam line data processing at JT-60 prototype neutral beam injector
International Nuclear Information System (INIS)
Horiike, Hiroshi; Kawai, Mikito; Ohara, Yoshihiro
1987-08-01
The present report describes the hard and soft wares of the data acquisition computer system for the prototype neutral injector unit for JT-60. In order to operate the unit, more than hundreds of signals of the beam line components have to be measured. These are mainly differential thermometers for the coolant waters and thermocouples for the beam dump components but not include those for the cryo system. Since the unit operates in a series of pulses, the measurement should be conducted very quickly in order to ensure the simultaneity of large number of the measured data. The present system actualize fast data acquisition using a small computer of 128 kB and measuring instruments connected through the bus. The system is connected to the JAERI computer center since the data capacity is fairly large to completely process them by the small computer. Therefore the measured data can be transferred to the computer center to calculate there, and the results can be received. After the system was completed the computer quickly print out the power flow data, which needed much work to calculate with hands. This system was very useful. It enhanced the experiments at the unit and reduced the labor. It enables us to early demonstrate the rated operation of the unit and to accurately estimate such operation data of the JT-60 NBI as the injection power. (author)
Phonons in low-dimensional systems
International Nuclear Information System (INIS)
Mayer, A P; Bonart, D; Strauch, D
2004-01-01
An introduction is given to the dynamical properties of crystalline systems having lattice-translational symmetry in less than three dimensions. These include surfaces of and interfaces between crystals, layered structures (2D lattice periodicity), bars and wires (1D lattice periodicity), as well as crystallites and clusters that have no lattice translational symmetry at all. In addition, superlattices are covered as artificial materials, giving rise to interesting dynamical effects. Crystal surfaces and crystalline bars are considered in some detail. For these systems, changes of the atomic equilibrium positions in comparison to the corresponding bulk crystals are also discussed since they frequently affect the dynamical properties
Internet-based dimensional verification system for reverse engineering processes
International Nuclear Information System (INIS)
Song, In Ho; Kim, Kyung Don; Chung, Sung Chong
2008-01-01
This paper proposes a design methodology for a Web-based collaborative system applicable to reverse engineering processes in a distributed environment. By using the developed system, design reviewers of new products are able to confirm geometric shapes, inspect dimensional information of products through measured point data, and exchange views with other design reviewers on the Web. In addition, it is applicable to verifying accuracy of production processes by manufacturing engineers. Functional requirements for designing this Web-based dimensional verification system are described in this paper. ActiveX-server architecture and OpenGL plug-in methods using ActiveX controls realize the proposed system. In the developed system, visualization and dimensional inspection of the measured point data are done directly on the Web: conversion of the point data into a CAD file or a VRML form is unnecessary. Dimensional verification results and design modification ideas are uploaded to markups and/or XML files during collaboration processes. Collaborators review the markup results created by others to produce a good design result on the Web. The use of XML files allows information sharing on the Web to be independent of the platform of the developed system. It is possible to diversify the information sharing capability among design collaborators. Validity and effectiveness of the developed system has been confirmed by case studies
Internet-based dimensional verification system for reverse engineering processes
Energy Technology Data Exchange (ETDEWEB)
Song, In Ho [Ajou University, Suwon (Korea, Republic of); Kim, Kyung Don [Small Business Corporation, Suwon (Korea, Republic of); Chung, Sung Chong [Hanyang University, Seoul (Korea, Republic of)
2008-07-15
This paper proposes a design methodology for a Web-based collaborative system applicable to reverse engineering processes in a distributed environment. By using the developed system, design reviewers of new products are able to confirm geometric shapes, inspect dimensional information of products through measured point data, and exchange views with other design reviewers on the Web. In addition, it is applicable to verifying accuracy of production processes by manufacturing engineers. Functional requirements for designing this Web-based dimensional verification system are described in this paper. ActiveX-server architecture and OpenGL plug-in methods using ActiveX controls realize the proposed system. In the developed system, visualization and dimensional inspection of the measured point data are done directly on the Web: conversion of the point data into a CAD file or a VRML form is unnecessary. Dimensional verification results and design modification ideas are uploaded to markups and/or XML files during collaboration processes. Collaborators review the markup results created by others to produce a good design result on the Web. The use of XML files allows information sharing on the Web to be independent of the platform of the developed system. It is possible to diversify the information sharing capability among design collaborators. Validity and effectiveness of the developed system has been confirmed by case studies
Xu, Cenke
Several examples of quantum spin systems and pseudo spin systems have been studied, and unconventional states of matters and phase transitions have been realized in all these systems under consideration. In the p +/- ip superconductor Josephson lattice and the p--band cold atomic system trapped in optical lattices, novel phases which behave similarly to 1+1 dimensional systems are realized, despite the fact that the real physical systems are in two or three dimensional spaces. For instance, by employing a spin-wave analysis together with a new duality transformation, we establish the existence and stability of a novel gapless "critical phase", which we refer to as a "bond algebraic liquid". This novel critical phase is analogous to the 1+1 dimensional algebraic boson liquid phase. The reason for the novel physics is that there is a quasilocal gauge symmetry in the effective low energy Hamiltonian. In a spin-1 system on the kagome lattice, and a hard-core boson system on the honeycomb lattice, the low energy physics is controlled by two components of compact U(1) gauge symmetries that emerge at low energy. Making use of the confinement nature of the 2+1 dimensional compact gauge theories and the powerful duality between gauge theories and height field theories, the crystalline phase diagrams are studied for both systems, and the transitions to other phases are also considered. These phase diagrams might be accessible in strongly correlated materials, or atomic systems in optical lattices. A novel quantum ground state of matter is realized in a bosonic model on three dimensional fcc lattice with emergent low energy excitations. The novel phase obtained is a stable gapless boson liquid phase, with algebraic boson density correlations. The stability of this phase is protected against the instanton effect and superfluidity by self-duality and large gauge symmetries on both sides of the duality. The gapless collective excitations of this phase closely resemble the
Sensibility Studies for the Neutral Beam Injection System in TJ-II
International Nuclear Information System (INIS)
Fuentes, C.; Liniers, M.; Guasp, J.
1999-01-01
The sensibility of the Neutral Beam Injection system of TJ-II to the changes of several parameters is analysed. Transmission, absorption and power loads at the intercepting structures are evaluated. The adopted values for the ion source distance, focal length and divergence are confirmed as optimal, showing a small sensitivity to changes, except for the divergence. The operational margins for beam misalignments has been found to be small but feasible, confirming also the reference directions as optimal. Finally four possible alternatives, intended to reduce the power loads at the beam entering structures, are analysed. All of them have been discarded since lead to the appearance of new risk zones, with unacceptable load levels, and reduce the transmitted power. (Author) 13 refs
Increased power delivery from the DIII-D neutral beam injection system
International Nuclear Information System (INIS)
Colleraine, A.P.; Callis, R.W.; Hong, R.M.; Kellman, D.H.; Kim, J.; Langhorn, A.R.; Lee, R.; Phillips, J.C.; Wight, J.J.
1989-12-01
The neutral beam system installed on the DIII-D tokamak employs eight 80 kV Long Pulse Sources (LPS) mounted on four beamlines and was originally designed to deliver a nominal 12 MW of H degree power to a plasma for pulses of up to 5 sec duration. Lawrence Berkeley Laboratory designed the LPS for the US Fusion Program to fill the requirements of both the DIII-D and the TFTR machines. Essentially all source components are of a common design; the DIII-D version is therefore conservative in its rated parameters. Recently a neutron shield has been constructed around the torus hall allowing D degree injection to become routine. Because deuterium beams have a better neutralization efficiency, the nominal power delivery per source has been measured to be approximately 2 MW (for a total of 16 MW) without any modifications. However, by reoptimizing the voltage gradients in the source, the perveance can be increased without degrading the optics. A change of gradient grid voltage from 0.83 V accel to 0.79 V accel raises the perveance from 2.5 to 3.0 μPerv with a corresponding gain in beam power of about 20%. The arc power required also must be increased to the range of 100 to 120 kW but this is well within the design limits of the LPS. Further studies of our systems are now underway to assess the possibilities of raising V accel above 80 kV. An additional gain in power is possible by this technique. 6 refs., 6 figs
Development of automatic control method for cryopump system for JT-60 neutral beam injector
International Nuclear Information System (INIS)
Shibanuma, Kiyoshi; Akino, Noboru; Dairaku, Masayuki; Ohuchi, Yutaka; Shibata, Takemasa
1991-10-01
A cryopump system for JT-60 neutral beam injector (NBI) is composed of 14 cryopumps with the largest total pumping speed of 20000 m 3 /s in the world, which are cooled by liquid helium through a long-distance liquid helium transferline of about 500 m from a helium refrigerator with the largest capacity of 3000 W at 3.6 K in Japan. An automatic control method of the cryopump system has been developed and tested. Features of the automatic control method are as follows. 1) Suppression control of the thermal imbalance in cooling-down of the 14 cryopumps. 2) Stable cooling control of the cryopump due to liquid helium supply to six cryopanels by natural circulation in steady-state mode. 3) Stable liquid helium supply control for the cryopumps from the liquid helium dewar in all operation modes of the cryopumps, considering the helium quantities held in respective components of the closed helium loop. 4) Stable control of the helium refrigerator for the fluctuation in thermal load from the cryopumps and the change of operation mode of the cryopumps. In the automatic operation of the cryopump system by the newly developed control method, the cryopump system including the refrigerator was stably operated for all operation modes of the cryopumps, so that the cool-down of 14 cryopumps was completed in 16 hours from the start of cool-down of the system and the cryopumps was stably cooled by natural circulation cooling in steady-state mode. (author)
Noise-induced drift in two-dimensional anisotropic systems
Farago, Oded
2017-10-01
We study the isothermal Brownian dynamics of a particle in a system with spatially varying diffusivity. Due to the heterogeneity of the system, the particle's mean displacement does not vanish even if it does not experience any physical force. This phenomenon has been termed "noise-induced drift," and has been extensively studied for one-dimensional systems. Here, we examine the noise-induced drift in a two-dimensional anisotropic system, characterized by a symmetric diffusion tensor with unequal diagonal elements. A general expression for the mean displacement vector is derived and presented as a sum of two vectors, depicting two distinct drifting effects. The first vector describes the tendency of the particle to drift toward the high diffusivity side in each orthogonal principal diffusion direction. This is a generalization of the well-known expression for the noise-induced drift in one-dimensional systems. The second vector represents a novel drifting effect, not found in one-dimensional systems, originating from the spatial rotation in the directions of the principal axes. The validity of the derived expressions is verified by using Langevin dynamics simulations. As a specific example, we consider the relative diffusion of two transmembrane proteins, and demonstrate that the average distance between them increases at a surprisingly fast rate of several tens of micrometers per second.
On the relation between plasma and neutral gas profiles in a cold gas-blanket system
International Nuclear Information System (INIS)
Bures, M.
1981-01-01
A solution for the neutral density profile using the measured plasma density and temperature gradients is presented. The fluid model is used. It is found that the penetration length for neutrals is underestimated in the situation where the integrated profiles are used. The ionization rate need not be inferred in the present calculation, because the ionization of neutrals diffusing into the plasma is implicitly included in measured profiles. This calculation is advantageous in the low temperature range where the ionization rate is a strongly varying function of temperature. Finally the presented solution indicates that the temperature gradient plays the essential role in the determination of the neutral density profile. (Auth.)
Electron localization in one-dimensional systems
International Nuclear Information System (INIS)
Chao, K.A.
1984-01-01
The pure regional localization and the global localization have been investigated via the inverse participation ratio and te moment analysis. If the envelop function of a localized state is more complicated than the simple exponential function e sup(-r/xi), the inverse participation ratio is inadequate to describe the localization properties of an electron. This is the case discovered recently in a stereo-irregular chain fo atoms including the electron-electron interaction and the structure disorder. The localization properties in this system are analysed in terms of the moments. (Author) [pt
Properties of interacting low-dimensional systems
Gumbs, Godfrey
2013-01-01
Filling the gap for comprehensive coverage of the realistic fundamentals and approaches needed to perform cutting-edge research on mesoscopic systems, this textbook allows advanced students to acquire and use the skills at a highly technical, research-qualifying level. Starting with a brief refresher to get all readers on an equal footing, the text moves on to a broad selection of advanced topics, backed by problems with solutions for use in classrooms as well as for self-study. Written by authors with research and teaching backgrounds from eminent institutions and based on a tried-and
Directory of Open Access Journals (Sweden)
Palanisamy Ramasamy
2017-11-01
Full Text Available A Unified Power Quality Conditioner (UPQC is designed using a Neutral Point Clamped (NPC multilevel inverter to improve the power quality. When designed for high/medium voltage and power applications, the voltage stress across the switches and harmonic content in the output voltage are increased. A 3-phase 4-wire NPC inverter system is developed as Power Quality Conditioner using an effectual three dimensional Space Vector Modulation (3D-SVM technique. The proposed system behaves like a UPQC with shunt and series active filter under balanced and unbalanced loading conditions. In addition to the improvement of the power quality issues, it also balances the neutral point voltage and voltage balancing across the capacitors under unbalanced condition. The hardware and simulation results of proposed system are compared with 2D-SVM and 3D-SVM. The proposed system is stimulated using MATLAB and the hardware is designed using FPGA. From the results it is evident that effectual 3D-SVM technique gives better performance compared to other control methods.
High heat flux engineering for the upgraded neutral beam injection systems of MAST-U
International Nuclear Information System (INIS)
Dhalla, F.; Mistry, S.; Turner, I.; Barrett, T.R.; Day, I.; McAdams, R.
2015-01-01
Highlights: • A new Residual Ion Dump (RID) and bend magnet system for the upgraded NBI systems have been designed for the 5 s MAST-U pulse requirements. • Design scoping was performed using numerical ion-tracing analysis software (MAGNET and OPERA codes). • A more powerful bending magnet will separate the residual ions into full, half and third energy components. • Three separate CuCrZr dumps spread the power loading resulting in acceptable power footprints. • FE thermo-mechanical analyses using ANSYS to validate the designs against the ITER SDC-IC code. • New bend magnet coils, yoke and CuCrZr water-cooled plates are in the procurement phase. - Abstract: For the initial phase of MAST-U operation the two existing neutral beam injection systems will be used, but must be substantially upgraded to fulfil expected operational requirements. The major elements are the design, manufacture and installation of a bespoke bending magnet and Residual Ion Dump (RID) system. The MAST-design full energy dump is being replaced with new actively-cooled full, half and third energy dumps, designed to receive 2.4 MW of ion power deflected by an iron-cored electromagnet. The main design challenge is limited space available in the vacuum vessel, requiring ion-deflection calculations to ensure acceptable heat flux distribution on the dump panels. This paper presents engineering and physics analysis of the upgraded MAST beamlines and reports the current status of manufacture.
Phase I Development of Neutral Beam Injector Solid-State Power System
Prager, James; Ziemba, Timothy; Miller, Kenneth E.; Slobodov, Ilia; Anderson, Seth
2017-10-01
Neutral beam injection (NBI) is an important tool for plasma heating, current drive and a diagnostic at fusion science experiments around the United States, including tokamaks, validation platform experiments, and privately funded fusion concepts. Currently, there are no vendors in the United States for NBI power systems. Eagle Harbor Technologies (EHT), Inc. is developing a new power system for NBI that takes advantage of the latest developments in solid-state switching. EHT has developed a resonant converter that can be scaled to the power levels required for NBI at small-scale validation platform experiments like the Lithium Tokamak Experiment. This power system can be used to modulate the NBI voltages over the course of a plasma shot, which can lead to improved control over the plasma. EHT will present initial modeling used to design this system as well as experimental data showing operation at 15 kV and 40 A for 10 ms into a test load. With support of DOE SBIR.
Three dimensional characterization and archiving system
International Nuclear Information System (INIS)
Clark, R.; Gallman, P.; Gaudreault, J.; Mosehauer, R.; Slotwinski, A.; Jarvis, G.; Griffiths, P.
1996-01-01
This system (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. It is in the final phase of a 3-phase program to support Decontamination and Decommissioning (D ampersand D) operations. Accurate physical characterization of surfaces and radioactive and organic contamination is a critical D ampersand D task. Surface characterization includes identification of dangerous inorganic materials such as asbestos and transite. 3D-ICAS robotically conveys a multisensor probe near the surfaces to be inspected, using coherent laser radar tracking, which also provides 3D facility maps. High-speed automated organic analysis is provided by means of gas chromatograph-mass spectrometer sensor which can process a sample without contact in one minute. Volatile organics are extracted directly from contaminated surfaces without sample removal; multiple stage focusing is used for high time resolution. Additional discrimination is obtained through a final stage time-of-flight mass spectrometer. The radionuclide sensors combines α, β, and γ counting with energy discrimination of the α channel; this quantifies isotopes of U, Pu, Th, Tc, Np, and Am in one minute. The Molecular Vibrational Spectrometry sensor is used to characterize substrate material such as concrete, transite, wood, or asbestos; this can be used to provide estimates of the depth of contamination. The 3D-ICAS will be available for real-time monitoring immediately after each 1 to 2 minute sample period. After surface mapping, 3-D displays will be provided showing contours of detected contaminant concentrations. Permanent measurement and contaminant level archiving will be provided, assuring data integrity and allowing regulatory review before and after D ampersand D operations
Generic Bell inequalities for multipartite mulit-dimensional systems
International Nuclear Information System (INIS)
Son, W.; Lee, J.; Kim, M.S.
2005-01-01
Full text: We present generic Bell inequalities for multipartite multi-dimensional systems. They utilize the set of measurements, which are coincident with the generalized version of Greenberger, Horne and Zeilinger (GHZ) paradox. The inequalities that must be satisfied by any local realistic theories are violated by quantum mechanics for even-dimensional multipartite systems. It is also shown that the maximal violation of the inequality is obtained by the generalized GHZ state, which is true multi-body nonseparable state. As a special case for the multipartite two-dimensional systems, it can be shown that the inequality agrees with Bell-Mermin version of inequality. Large sets of variants are shown to naturally emerge from the generic Bell inequalities. We will discuss the particular variants of Bell inequalities that are violated for all the systems including odd-dimensional multipartite systems. Interestingly the variants can be reduced into the Clauser-Horne-Shimony-Holt (CHSH) inequality as well as Ardehali inequality. (author)
Hidalgo-Rodríguez, Marta; Soriano-Meseguer, Sara; Fuguet, Elisabet; Ràfols, Clara; Rosés, Martí
2013-12-18
Several chromatographic systems (three systems of high-performance liquid chromatography and two micellar electrokinetic chromatography systems) besides the reference octanol-water partition system are evaluated by a systematic procedure previously proposed in order to know their ability to model human skin permeation. The precision achieved when skin-water permeability coefficients are correlated against chromatographic retention factors is predicted within the framework of the solvation parameter model. It consists in estimating the contribution of error due to the biological and chromatographic data, as well as the error coming from the dissimilarity between the human skin permeation and the chromatographic systems. Both predictions and experimental tests show that all correlations are greatly affected by the considerable uncertainty of the skin permeability data and the error associated to the dissimilarity between the systems. Correlations with much better predictive abilities are achieved when the volume of the solute is used as additional variable, which illustrates the main roles of both lipophilicity and size of the solute to penetrate through the skin. In this way, the considered systems are able to give precise estimations of human skin permeability coefficients. In particular, the HPLC systems with common C18 columns provide the best performances in emulating the permeation of neutral compounds from aqueous solution through the human skin. As a result, a methodology based on easy, fast, and economical HPLC measurements in a common C18 column has been developed. After a validation based on training and test sets, the method has been applied with good results to the estimation of skin permeation of several hormones and pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.
Methodology for dimensional variation analysis of ITER integrated systems
International Nuclear Information System (INIS)
Fuentes, F. Javier; Trouvé, Vincent; Cordier, Jean-Jacques; Reich, Jens
2016-01-01
Highlights: • Tokamak dimensional management methodology, based on 3D variation analysis, is presented. • Dimensional Variation Model implementation workflow is described. • Methodology phases are described in detail. The application of this methodology to the tolerance analysis of ITER Vacuum Vessel is presented. • Dimensional studies are a valuable tool for the assessment of Tokamak PCR (Project Change Requests), DR (Deviation Requests) and NCR (Non-Conformance Reports). - Abstract: The ITER machine consists of a large number of complex systems highly integrated, with critical functional requirements and reduced design clearances to minimize the impact in cost and performances. Tolerances and assembly accuracies in critical areas could have a serious impact in the final performances, compromising the machine assembly and plasma operation. The management of tolerances allocated to part manufacture and assembly processes, as well as the control of potential deviations and early mitigation of non-compliances with the technical requirements, is a critical activity on the project life cycle. A 3D tolerance simulation analysis of ITER Tokamak machine has been developed based on 3DCS dedicated software. This integrated dimensional variation model is representative of Tokamak manufacturing functional tolerances and assembly processes, predicting accurate values for the amount of variation on critical areas. This paper describes the detailed methodology to implement and update the Tokamak Dimensional Variation Model. The model is managed at system level. The methodology phases are illustrated by its application to the Vacuum Vessel (VV), considering the status of maturity of VV dimensional variation model. The following topics are described in this paper: • Model description and constraints. • Model implementation workflow. • Management of input and output data. • Statistical analysis and risk assessment. The management of the integration studies based on
Methodology for dimensional variation analysis of ITER integrated systems
Energy Technology Data Exchange (ETDEWEB)
Fuentes, F. Javier, E-mail: FranciscoJavier.Fuentes@iter.org [ITER Organization, Route de Vinon-sur-Verdon—CS 90046, 13067 St Paul-lez-Durance (France); Trouvé, Vincent [Assystem Engineering & Operation Services, rue J-M Jacquard CS 60117, 84120 Pertuis (France); Cordier, Jean-Jacques; Reich, Jens [ITER Organization, Route de Vinon-sur-Verdon—CS 90046, 13067 St Paul-lez-Durance (France)
2016-11-01
Highlights: • Tokamak dimensional management methodology, based on 3D variation analysis, is presented. • Dimensional Variation Model implementation workflow is described. • Methodology phases are described in detail. The application of this methodology to the tolerance analysis of ITER Vacuum Vessel is presented. • Dimensional studies are a valuable tool for the assessment of Tokamak PCR (Project Change Requests), DR (Deviation Requests) and NCR (Non-Conformance Reports). - Abstract: The ITER machine consists of a large number of complex systems highly integrated, with critical functional requirements and reduced design clearances to minimize the impact in cost and performances. Tolerances and assembly accuracies in critical areas could have a serious impact in the final performances, compromising the machine assembly and plasma operation. The management of tolerances allocated to part manufacture and assembly processes, as well as the control of potential deviations and early mitigation of non-compliances with the technical requirements, is a critical activity on the project life cycle. A 3D tolerance simulation analysis of ITER Tokamak machine has been developed based on 3DCS dedicated software. This integrated dimensional variation model is representative of Tokamak manufacturing functional tolerances and assembly processes, predicting accurate values for the amount of variation on critical areas. This paper describes the detailed methodology to implement and update the Tokamak Dimensional Variation Model. The model is managed at system level. The methodology phases are illustrated by its application to the Vacuum Vessel (VV), considering the status of maturity of VV dimensional variation model. The following topics are described in this paper: • Model description and constraints. • Model implementation workflow. • Management of input and output data. • Statistical analysis and risk assessment. The management of the integration studies based on
Two-dimensional approach to relativistic positioning systems
International Nuclear Information System (INIS)
Coll, Bartolome; Ferrando, Joan Josep; Morales, Juan Antonio
2006-01-01
A relativistic positioning system is a physical realization of a coordinate system consisting in four clocks in arbitrary motion broadcasting their proper times. The basic elements of the relativistic positioning systems are presented in the two-dimensional case. This simplified approach allows to explain and to analyze the properties and interest of these new systems. The positioning system defined by geodesic emitters in flat metric is developed in detail. The information that the data generated by a relativistic positioning system give on the space-time metric interval is analyzed, and the interest of these results in gravimetry is pointed out
International Nuclear Information System (INIS)
Kalin, Margarete; Fyson, Andrew; Wheeler, William N.
2006-01-01
The oxidation of pyritic mining waste is a self-perpetuating corrosive process which generates acid mine drainage (AMD) effluent for centuries or longer. The chemical neutralization of these complex, buffered effluents result in unstable, metal-laden sludges, which require disposal to minimize long-term environmental consequences. A variety of passive treatment systems for AMD, developed in the past two decades, combine limestone and organic substrates in constructed wetlands. These systems work well initially but over the longer term fail due to clogging with and the depletion of available organic carbon. However, some ecologically engineered systems, which exploit the activities of acid reducing microbes in the sediment, rely on photosynthesis in the water column as a source of organic matter. The primary productivity in the water column, which also generates some alkalinity, provides electron donors for the microbial reduction processes in the sediment. In its consideration of 'passive' systems, the literature has placed undue emphasis on sulphate reduction; thermodynamical iron reduction is equally important as is the need to prevent iron oxidation. Secondary precipitates of iron play a significant role in sediment-driven biomineralization processes, which affect the anaerobic degradation of organic matter and the stability of the resulting metal sulfides. One such passive system, which utilized a floating root mass as a source of organic carbon, is described. An extensive review of the literature and the chemical and biogeochemical reactions of AMD treatment systems, lead to the conclusion, that sediment based ecological systems offer the greatest potential for the sustainable treatment of AMD
Kalin, Margarete; Fyson, Andrew; Wheeler, William N
2006-08-01
The oxidation of pyritic mining waste is a self-perpetuating corrosive process which generates acid mine drainage (AMD) effluent for centuries or longer. The chemical neutralization of these complex, buffered effluents result in unstable, metal-laden sludges, which require disposal to minimize long-term environmental consequences. A variety of passive treatment systems for AMD, developed in the past two decades, combine limestone and organic substrates in constructed wetlands. These systems work well initially but over the longer term fail due to clogging with and the depletion of available organic carbon. However, some ecologically engineered systems, which exploit the activities of acid reducing microbes in the sediment, rely on photosynthesis in the water column as a source of organic matter. The primary productivity in the water column, which also generates some alkalinity, provides electron donors for the microbial reduction processes in the sediment. In its consideration of 'passive' systems, the literature has placed undue emphasis on sulphate reduction; thermodynamical iron reduction is equally important as is the need to prevent iron oxidation. Secondary precipitates of iron play a significant role in sediment-driven biomineralization processes, which affect the anaerobic degradation of organic matter and the stability of the resulting metal sulfides. One such passive system, which utilized a floating root mass as a source of organic carbon, is described. An extensive review of the literature and the chemical and biogeochemical reactions of AMD treatment systems, lead to the conclusion, that sediment based ecological systems offer the greatest potential for the sustainable treatment of AMD.
Consistent Probabilistic Description of the Neutral Kaon System: Novel Observable Effects
Bernabeu, J.; Villanueva-Perez, P.
2013-01-01
The neutral Kaon system has both CP violation in the mass matrix and a non-vanishing lifetime difference in the width matrix. This leads to an effective Hamiltonian which is not a normal operator, with incompatible (non-commuting) masses and widths. In the Weisskopf-Wigner Approach (WWA), by diagonalizing the entire Hamiltonian, the unphysical non-orthogonal "stationary" states $K_{L,S}$ are obtained. These states have complex eigenvalues whose real (imaginary) part does not coincide with the eigenvalues of the mass (width) matrix. In this work we describe the system as an open Lindblad-type quantum mechanical system due to Kaon decays. This approach, in terms of density matrices for initial and final states, provides a consistent probabilistic description, avoiding the standard problems because the width matrix becomes a composite operator not included in the Hamiltonian. We consider the dominant-decay channel to two pions, so that one of the Kaon states with definite lifetime becomes stable. This new approa...
Design and implementation of a Macintosh-CAMAC based system for neutral beam diagnostics
International Nuclear Information System (INIS)
Wight, J.; Hong, R.M.; Phillips, J.C.; Lee, R.L.; Colleraine, A.P.; Kim, J.
1989-12-01
An automated personal computer based CAMAC data acquisition system is being implemented on the DIII-D neutral beamlines for certain diagnostics. The waterflow calorimetry (WFC) diagnostic is the first system to be upgraded. It includes data acquisition by a Macintosh II computer containing a National Instruments IEEE-488 card, and running their LabView software. Macintosh to CAMAC communications are carried out through an IEEE-488 crate controller. The Doppler shift spectroscopy, residual gas analysis, and armor tile infrared image diagnostics will be modified in similar ways. To reduce the demand for Macintosh CPU time, the extensive serial high-way data activity is performed by means of a new Kinetic Systems 3982 List sequencing Crate Controller dedicated to these operations. A simple Local Area Network file server is used to store data from all diagnostics together, and in a format readable by a standard commercial database. This reduces the problem of redundant data storage and allows simpler inter-diagnostic analysis. 3 refs., 4 figs
Multi-dimensional virtual system introduced to enhance canonical sampling
Higo, Junichi; Kasahara, Kota; Nakamura, Haruki
2017-10-01
When an important process of a molecular system occurs via a combination of two or more rare events, which occur almost independently to one another, computational sampling for the important process is difficult. Here, to sample such a process effectively, we developed a new method, named the "multi-dimensional Virtual-system coupled Monte Carlo (multi-dimensional-VcMC)" method, where the system interacts with a virtual system expressed by two or more virtual coordinates. Each virtual coordinate controls sampling along a reaction coordinate. By setting multiple reaction coordinates to be related to the corresponding rare events, sampling of the important process can be enhanced. An advantage of multi-dimensional-VcMC is its simplicity: Namely, the conformation moves widely in the multi-dimensional reaction coordinate space without knowledge of canonical distribution functions of the system. To examine the effectiveness of the algorithm, we introduced a toy model where two molecules (receptor and its ligand) bind and unbind to each other. The receptor has a deep binding pocket, to which the ligand enters for binding. Furthermore, a gate is set at the entrance of the pocket, and the gate is usually closed. Thus, the molecular binding takes place via the two events: ligand approach to the pocket and gate opening. In two-dimensional (2D)-VcMC, the two molecules exhibited repeated binding and unbinding, and an equilibrated distribution was obtained as expected. A conventional canonical simulation, which was 200 times longer than 2D-VcMC, failed in sampling the binding/unbinding effectively. The current method is applicable to various biological systems.
Three-Dimensional Extension of a Digital Library Service System
Xiao, Long
2010-01-01
Purpose: The paper aims to provide an overall methodology and case study for the innovation and extension of a digital library, especially the service system. Design/methodology/approach: Based on the three-dimensional structure theory of the information service industry, this paper combines a comprehensive analysis with the practical experiences…
Second invariant for two-dimensional classical super systems
Indian Academy of Sciences (India)
Construction of superpotentials for two-dimensional classical super systems (for N. 2) is carried ... extensively used for the case of non-linear partial differential equation by various authors. [3,4–7,12 ..... found to be integrable just by accident.
Kondo effect in three-dimensional Dirac and Weyl systems
Mitchell, Andrew K.; Fritz, Lars
2015-01-01
Magnetic impurities in three-dimensional Dirac and Weyl systems are shown to exhibit a fascinatingly diverse range of Kondo physics, with distinctive experimental spectroscopic signatures. When the Fermi level is precisely at the Dirac point, Dirac semimetals are in fact unlikely candidates for a
Statistics of resonances in one-dimensional continuous systems
Indian Academy of Sciences (India)
Vol. 73, No. 3. — journal of. September 2009 physics pp. 565–572. Statistics of resonances in one-dimensional continuous systems. JOSHUA FEINBERG. Physics Department, University of Haifa at Oranim, Tivon 36006, Israel ..... relativistic quantum mechanics (Israel Program for Scientific Translations, Jerusalem,. 1969).
Three-dimensional computer models of electrospinning systems
Directory of Open Access Journals (Sweden)
Smółka Krzysztof
2017-12-01
Full Text Available Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.
Patched Green's function techniques for two-dimensional systems
DEFF Research Database (Denmark)
Settnes, Mikkel; Power, Stephen; Lin, Jun
2015-01-01
We present a numerically efficient technique to evaluate the Green's function for extended two-dimensional systems without relying on periodic boundary conditions. Different regions of interest, or “patches,” are connected using self-energy terms which encode the information of the extended parts...
Light propagation in one-dimensional porous silicon complex systems
Oton, C.J.; Dal Negro, L.; Gaburro, Z.; Pavesi, L.; Johnson, P.J.; Lagendijk, Aart; Wiersma, D.S.
2003-01-01
We discuss the optical properties of one-dimensional complex dielectric systems, in particular the time-resolved transmission through thick porous silicon quasiperiodic multi-layers. Both in numerical calculations and experiments we find dramatic distortion effects, i.e. pulse stretching and
Equilibrium spherically curved two-dimensional Lennard-Jones systems
Voogd, J.M.; Sloot, P.M.A.; van Dantzig, R.
2005-01-01
To learn about basic aspects of nano-scale spherical molecular shells during their formation, spherically curved two-dimensional N-particle Lennard-Jones systems are simulated, studying curvature evolution paths at zero-temperature. For many N-values (N < 800) equilibrium configu- rations are traced
Directory of Open Access Journals (Sweden)
Hamid Reza Karimi
2009-01-01
Full Text Available The problem of stability analysis for a class of neutral systems with mixed time-varying neutral, discrete and distributed delays and nonlinear parameter perturbations is addressed. By introducing a novel Lyapunov-Krasovskii functional and combining the descriptor model transformation, the Leibniz-Newton formula, some free-weighting matrices, and a suitable change of variables, new sufficient conditions are established for the stability of the considered system, which are neutral-delay-dependent, discrete-delay-range-dependent, and distributed-delay-dependent. The conditions are presented in terms of linear matrix inequalities (LMIs and can be efficiently solved using convex programming techniques. Two numerical examples are given to illustrate the efficiency of the proposed method.
Application of 3-dimensional CAD modeling system in nuclear plants
International Nuclear Information System (INIS)
Suwa, Minoru; Saito, Shunji; Nobuhiro, Minoru
1990-01-01
Until now, the preliminary work for mutual components in nuclear plant were readied by using plastic models. Recently with the development of computer graphic techniques, we can display the components on the graphics terminal, better than with use of plastic model and actual plants. The computer model can be handled, both telescopically and microscopically. A computer technique called 3-dimensional CAD modeling system was used as the preliminary work and design system. Through application of this system, database for nuclear plants was completed in arrangement step. The data can be used for piping design, stress analysis, shop production, testing and site construction, in all steps. In addition, the data can be used for various planning works, even after starting operation of plant. This paper describes the outline of the 3-dimensional CAD modeling system. (author)
Application of the code Slac to the study of Ion Extraction Systems in Neutral Injectors
International Nuclear Information System (INIS)
Garcia, M.; Liniers, M.; Guasp, J.
1997-01-01
In this study different extraction geometries for intense ion beams have been analyzed with the code SLAC, in view of its possible application to the neutral injectors of TJ-II. With this aim, we have introduced several modifications in the code in order to correctly simulate the transition between the ion source plasma and the extraction region, which has great impact on the beam optics. These modifications include the introduction of a population of Boltzmann electrons in the transition region, and the implementation of an option to simulate the thermal velocity of the ions in the source. We have found a better agreement between the results obtained with the new version of the code and the experimental data in two well known systems. With this new version of the code two different studies have been carried out: in the first place an optimization of the ATF injectors extraction system for its use on TJ-II, leading to an optimum value of the gap in the energy range 30-40 KeV, and in the second place a systematic study of extraction geometries at 40 KeV. As a result of this second study we have found the combinations of parameters that can be used under different working conditions (e.g. different pulse lengths), leading to acceptable values of the beam divergence. (Author)
Linear Port-Hamiltonian Systems on Infinite-dimensional Spaces
Jacob, Birgit
2012-01-01
This book provides a self-contained introduction to the theory of infinite-dimensional systems theory and its applications to port-Hamiltonian systems. The textbook starts with elementary known results, then progresses smoothly to advanced topics in current research. Many physical systems can be formulated using a Hamiltonian framework, leading to models described by ordinary or partial differential equations. For the purpose of control and for the interconnection of two or more Hamiltonian systems it is essential to take into account this interaction with the environment. This book is the fir
Solitons in one-dimensional charge density wave systems
International Nuclear Information System (INIS)
Su, W.P.
1981-01-01
Theoretical research on one dimensional charge density wave systems is outlined. A simple coupled electron-photon Hamiltonian is studied including a Green's function approach, molecular dynamics, and Monte Carlo path integral method. As in superconductivity, the nonperturbative nature of the system makes the physical ground states and low energy excitations drastically different from the bare electrons and phonons. Solitons carry quantum numbers which are entirely different from those of the bare electrons and holes. The fractional charge character of the solitons is an example of this fact. Solitons are conveniently generated by doping material with donors or acceptors or by photon absorption. Most predictions of the theory are in qualitative agreement with experiments. The one dimensional charge density wave system has potential technological importance and a possible role in uncovering phenomena which might have implications in relativistic field theory and elementary particle physics
Sequentially generated states for the study of two dimensional systems
Energy Technology Data Exchange (ETDEWEB)
Banuls, Mari-Carmen; Cirac, J. Ignacio [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Perez-Garcia, David [Depto. Analisis Matematico, Universidad Complutense de Madrid (Spain); Wolf, Michael M. [Niels Bohr Institut, Copenhagen (Denmark); Verstraete, Frank [Fakultaet fuer Physik, Universitaet Wien (Austria)
2009-07-01
The family of Matrix Product States represents a powerful tool for the study of physical one-dimensional quantum many-body systems, such as spin chains. Besides, Matrix Product States can be defined as the family of quantum states that can be sequentially generated in a one-dimensional system. We have introduced a new family of states which extends this sequential definition to two dimensions. Like in Matrix Product States, expectation values of few body observables can be efficiently evaluated and, for the case of translationally invariant systems, the correlation functions decay exponentially with the distance. We show that such states are a subclass of Projected Entangled Pair States and investigate their suitability for approximating the ground states of local Hamiltonians.
Blended particle filters for large-dimensional chaotic dynamical systems
Majda, Andrew J.; Qi, Di; Sapsis, Themistoklis P.
2014-01-01
A major challenge in contemporary data science is the development of statistically accurate particle filters to capture non-Gaussian features in large-dimensional chaotic dynamical systems. Blended particle filters that capture non-Gaussian features in an adaptively evolving low-dimensional subspace through particles interacting with evolving Gaussian statistics on the remaining portion of phase space are introduced here. These blended particle filters are constructed in this paper through a mathematical formalism involving conditional Gaussian mixtures combined with statistically nonlinear forecast models compatible with this structure developed recently with high skill for uncertainty quantification. Stringent test cases for filtering involving the 40-dimensional Lorenz 96 model with a 5-dimensional adaptive subspace for nonlinear blended filtering in various turbulent regimes with at least nine positive Lyapunov exponents are used here. These cases demonstrate the high skill of the blended particle filter algorithms in capturing both highly non-Gaussian dynamical features as well as crucial nonlinear statistics for accurate filtering in extreme filtering regimes with sparse infrequent high-quality observations. The formalism developed here is also useful for multiscale filtering of turbulent systems and a simple application is sketched below. PMID:24825886
Suppression of fast electron leakage from large openings in a plasma neutralizer for N-NB systems
International Nuclear Information System (INIS)
Kashiwagi, Mieko; Hanada, Masaya; Yamana, Takashi; Inoue, Takashi; Imai, Tsuyoshi; Taniguchi, Masaki; Watanabe, Kazuhiro
2006-01-01
To produce highly ionized plasmas at low operating pressure in a plasma neutralizer of negative ion based neutral beam (N-NB) systems, it is a critical issue to suppress leakage of fast electrons through large openings as the beam entrance/exit. The authors propose to form weak transverse magnetic fields without a significant beam deflection, called the shield field, across the large openings of the neutralizer. A numerical study showed that the shield field of only few tens of Gauss is sufficient to suppress the fast electron leakage from the openings. By measuring of an electron energy distribution function (EEDF), it was confirmed that such a weak magnetic field is enough to repel the fast electrons back into the neutralizer plasma. As the result, the plasma density increased with the shield field strength and saturated at 30 G. The plasma density reached 50% higher value than that without the shield field. Thus it was found that reflected fast electrons by the shield field of only 30 G work effectively for the plasma generation. It was also estimated that such a weak magnetic field sufficiently suppresses the deflection of a 1 MeV beam. This weak magnetic field would be applicable to the plasma neutralizer for the fusion demonstration (DEMO) plant
Long-pulse neutral beam power supply system for LBL 20 kV, 10 A sources
International Nuclear Information System (INIS)
Honey, V.J.; Baker, W.R.; Fitzgerald, M.L.
1976-05-01
A description is given of the power supplies and control system for the LBL 20 kV, 10 A, 10 sec long-pulse neutral beam source test facility, now in operation. Such sources are used in a number of existing and planned fusion power experiments
Design of Data Acquisition and Control System for Indian Test Facility of Diagnostics Neutral Beam
International Nuclear Information System (INIS)
Soni, Jignesh; Tyagi, Himanshu; Yadav, Ratnakar; Rotti, Chandramouli; Bandyopadhyay, Mainak; Bansal, Gourab; Gahluat, Agrajit; Sudhir, Dass; Joshi, Jaydeep; Prasad, Rambilas; Pandya, Kaushal; Shah, Sejal; Parmar, Deepak; Chakraborty, Arun
2015-01-01
Highlights: • More than 900 channels Data Acquisition and Control System. • INTF DACS has been designed based on ITER-PCDH guidelines. • Separate Interlock and Safety system designed based on IEC 61508 standard. • Hardware selected from ITER slow controller and fast controller catalog. • Software framework based on ITER CODAC Core System and LabVIEW software. - Abstract: The Indian Test Facility (INTF) – a negative hydrogen ion based 100 kV, 60 A, 5 Hz modulated NBI system having 3 s ON/20 s OFF duty cycle. Prime objective of the facility is to install a full-scale test bed for the qualification of all Diagnostic Neutral Beam (DNB) parameters, prior to installation in ITER. The automated and safe operation of the INTF will require a reliable and rugged instrumentation and control system which provide control, data acquisition (DAQ), interlock and safety functions, referred as INTF-DACS. The INTF-DACS has been decided to be design based on the ITER CODAC architecture and ITER-PCDH guidelines since the technical understanding of CODAC technology gained from this will later be helpful in development of plant system I&C for DNB. For complete operation of the INTF, approximately 900 numbers of signals are required to be superintending by the DACS. In INTF conventional control loop time required is within the range of 5–100 ms and for DAQ except high-end diagnostics, required sampling rates in range of 5 sample per second (Sps) to 10 kSps; to fulfill these requirements hardware components have been selected from the ITER slow and fast controller catalogs. For high-end diagnostics required sampling rates up to 100 MSps normally in case of certain events, therefore event and burst based DAQ hardware has been finalized. Combined use of CODAC core software (CCS) and NI-LabVIEW has been finalized due to the fact that full required DAQ support is not available in present version of CCS. Interlock system for investment protection of facility and Safety system for
Design of Data Acquisition and Control System for Indian Test Facility of Diagnostics Neutral Beam
Energy Technology Data Exchange (ETDEWEB)
Soni, Jignesh, E-mail: jsoni@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Tyagi, Himanshu; Yadav, Ratnakar; Rotti, Chandramouli; Bandyopadhyay, Mainak [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Bansal, Gourab; Gahluat, Agrajit [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Sudhir, Dass; Joshi, Jaydeep; Prasad, Rambilas [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Pandya, Kaushal [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Shah, Sejal; Parmar, Deepak [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Chakraborty, Arun [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India)
2015-10-15
Highlights: • More than 900 channels Data Acquisition and Control System. • INTF DACS has been designed based on ITER-PCDH guidelines. • Separate Interlock and Safety system designed based on IEC 61508 standard. • Hardware selected from ITER slow controller and fast controller catalog. • Software framework based on ITER CODAC Core System and LabVIEW software. - Abstract: The Indian Test Facility (INTF) – a negative hydrogen ion based 100 kV, 60 A, 5 Hz modulated NBI system having 3 s ON/20 s OFF duty cycle. Prime objective of the facility is to install a full-scale test bed for the qualification of all Diagnostic Neutral Beam (DNB) parameters, prior to installation in ITER. The automated and safe operation of the INTF will require a reliable and rugged instrumentation and control system which provide control, data acquisition (DAQ), interlock and safety functions, referred as INTF-DACS. The INTF-DACS has been decided to be design based on the ITER CODAC architecture and ITER-PCDH guidelines since the technical understanding of CODAC technology gained from this will later be helpful in development of plant system I&C for DNB. For complete operation of the INTF, approximately 900 numbers of signals are required to be superintending by the DACS. In INTF conventional control loop time required is within the range of 5–100 ms and for DAQ except high-end diagnostics, required sampling rates in range of 5 sample per second (Sps) to 10 kSps; to fulfill these requirements hardware components have been selected from the ITER slow and fast controller catalogs. For high-end diagnostics required sampling rates up to 100 MSps normally in case of certain events, therefore event and burst based DAQ hardware has been finalized. Combined use of CODAC core software (CCS) and NI-LabVIEW has been finalized due to the fact that full required DAQ support is not available in present version of CCS. Interlock system for investment protection of facility and Safety system for
On neutral plasma oscillations
International Nuclear Information System (INIS)
Shadwick, B.A.; Morrison, P.J.
1993-06-01
We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can possess positive or negative free energy
On neutral plasma oscillations
International Nuclear Information System (INIS)
Shadwick, B.A.; Texas Univ., Austin; Morrison, P.J.; Texas Univ., Austin
1994-01-01
We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can posses positive or negative free energy. (orig.)
Positive periodic solutions of periodic neutral Lotka-Volterra system with distributed delays
International Nuclear Information System (INIS)
Li Yongkun
2008-01-01
By using a fixed point theorem of strict-set-contraction, some criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with distributed delays (dx i (t))/(dt) =x i (t)[a i (t)-Σ j=1 n b ij (t)∫ -T ij 0 K ij (θ)x j ( t+θ)dθ-Σ j=1 n c ij (t)∫ -T ij 0 K ij (θ) x j ' (t+θ)dθ],i=1,2,...,n, where a i ,b ij ,c ij element of C(R,R + ) (i, j = 1, 2, ..., n) are ω-periodic functions, T ij ,T ij element of (0,∞) (i, j = 1, 2, ..., n) and K ij ,K ij element of (R,R + ) satisfying ∫ -T ij 0 K ij (θ)dθ=1,∫ -T ij 0 K ij (θ)dθ=1, i, j = 1, 2, ..., n
Regeneration and tritium recovery from the large JET neutral injection cryopump system after the FTE
International Nuclear Information System (INIS)
Obert, W.; Bell, A.; Davies, J.; Mayaux, C.; Perinic, G.; Saibene, G.; Sartori, R.; Thompson, E.; Anderson, J.; Jenkins, E.; Walthers, C.
1992-01-01
Neutral Beam Injection (NBI) was used to introduce tritium into the plasma for the First Tritium Experiment In addition to the decisive advantage of depositing the tritium into the centre of the plasma, the use of NBI also minimized the total quantity of tritium introduced into the Torus and the contamination of the vacuum vessel. However, because of the relatively low gas efficiency of the positive ion injection system approximately 95% of the total quantity of tritium introduced was pumped by the large condensation cryopumps which form an integral part of the injector. Several hardware and associated software changes were implemented in order to making provision for possible fault scenarios during operation with tritium and to ensure complete regeneration of the tritium from the cryopumps. The tritium released after all subsequent regeneration's has been monitored carefully in order to determine the amount of tritium retained by the black anodized liquid nitrogen panel surfaces of the cryopump and to compare it with experiments at TSTA on JET samples before the FTE
Design of arc power supply for neutral beam injection system based on super capacitor energy storage
International Nuclear Information System (INIS)
Yang Puqiong; Xuan Weimin; Cao Jianyong; Li Qing; Liu Xiaolong
2015-01-01
The arc power supply is one of the most important equipment for neutral beam injection system. The stability of arc discharge and the quality of ion beam extraction were determined by its performance. For improving stability of the arc discharge, reducing the power network capacity and decreasing impulse on power network, the topology of the arc power supply applied the structure of DC/DC converter based on technology of super capacitor energy storage and switching power supply. Several IGBT power modules are operated in parallel, and it can improve the arc power supply's operating frequency and dynamic response. A filter circuit and a current fast transferring circuit were designed based on a detailed analysis on working process of the arc power sup- ply. According to the requirements and parameters of the arc power supply, and the current response of RL first order circuit, the minimum filter inductances were accurately calculated. Finally, using the model and Matlab, the performance of the arc power supply was simulated and verified, and it meets the design requirement. (authors)
Three-dimensional computer aided design system for plant layout
International Nuclear Information System (INIS)
Yoshinaga, Toshiaki; Kiguchi, Takashi; Tokumasu, Shinji; Kumamoto, Kenjiro.
1986-01-01
The CAD system for three-dimensional plant layout planning, with which the layout of pipings, cable trays, air conditioning ducts and so on in nuclear power plants can be planned and designed effectively in a short period is reported. This system comprises the automatic routing system by storing the rich experience and know-how of designers in a computer as the knowledge, and deciding the layout automatically following the predetermined sequence by using these, the interactive layout system for reviewing the routing results from higher level and modifying to the optimum layout, the layout evaluation system for synthetically evaluating the layout from the viewpoint of the operability such as checkup and maintenance, and the data base system which enables these effective planning and design. In this report, the total constitution of this system and the technical features and effects of the individual subsystems are outlined. In this CAD system for three-dimensional plant layout planning, knowledge engineering, CAD/CAM, computer graphics and other latest technology were introduced, accordingly by applying this system to plant design, the design can be performed quickly, various case studies can be carried out at planning stage, and systematic and optimum layout planning becomes possible. (Kako, I.)
Magnetometry of low-dimensional electron and hole systems
Energy Technology Data Exchange (ETDEWEB)
Usher, A [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Elliott, M [School of Physics and Astronomy, Cardiff University, Queens Buildings, Cardiff CF24 3AA (United Kingdom)], E-mail: a.usher@exeter.ac.uk, E-mail: elliottm@cf.ac.uk
2009-03-11
The high-magnetic-field, low-temperature magnetic properties of low-dimensional electron and hole systems reveal a wealth of fundamental information. Quantum oscillations of the thermodynamic equilibrium magnetization yield the total density of states, a central quantity in understanding the quantum Hall effect in 2D systems. The magnetization arising from non-equilibrium circulating currents reveals details, not accessible with traditional measurements, of the vanishingly small longitudinal resistance in the quantum Hall regime. We review how the technique of magnetometry has been applied to these systems, the most important discoveries that have been made, and their theoretical significance. (topical review)
Three-dimensional integrated CAE system applying computer graphic technique
International Nuclear Information System (INIS)
Kato, Toshisada; Tanaka, Kazuo; Akitomo, Norio; Obata, Tokayasu.
1991-01-01
A three-dimensional CAE system for nuclear power plant design is presented. This system utilizes high-speed computer graphic techniques for the plant design review, and an integrated engineering database for handling the large amount of nuclear power plant engineering data in a unified data format. Applying this system makes it possible to construct a nuclear power plant using only computer data from the basic design phase to the manufacturing phase, and it increases the productivity and reliability of the nuclear power plants. (author)
Thermal conductivity in one-dimensional nonlinear systems
Politi, Antonio; Giardinà, Cristian; Livi, Roberto; Vassalli, Massimo
2000-03-01
Thermal conducitivity of one-dimensional nonlinear systems typically diverges in the thermodynamic limit, whenever the momentum is conserved (i.e. in the absence of interactions with an external substrate). Evidence comes from detailed studies of Fermi-Pasta-Ulam and diatomic Toda chains. Here, we discuss the first example of a one-dimensional system obeying Fourier law : a chain of coupled rotators. Numerical estimates of the thermal conductivity obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of the rotator model.
Aspects of jamming in two-dimensional athermal frictionless systems.
Reichhardt, C; Reichhardt, C J Olson
2014-05-07
In this work we provide an overview of jamming transitions in two dimensional systems focusing on the limit of frictionless particle interactions in the absence of thermal fluctuations. We first discuss jamming in systems with short range repulsive interactions, where the onset of jamming occurs at a critical packing density and where certain quantities show a divergence indicative of critical behavior. We describe how aspects of the dynamics change as the jamming density is approached and how these dynamics can be explored using externally driven probes. Different particle shapes can produce jamming densities much lower than those observed for disk-shaped particles, and we show how jamming exhibits fragility for some shapes while for other shapes this is absent. Next we describe the effects of long range interactions and jamming behavior in systems such as charged colloids, vortices in type-II superconductors, and dislocations. We consider the effect of adding obstacles to frictionless jamming systems and discuss connections between this type of jamming and systems that exhibit depinning transitions. Finally, we discuss open questions such as whether the jamming transition in all these different systems can be described by the same or a small subset of universal behaviors, as well as future directions for studies of jamming transitions in two dimensional systems, such as jamming in self-driven or active matter systems.
Statistical mechanical analysis of (1 + ∞) dimensional disordered systems
International Nuclear Information System (INIS)
Skantzos, Nikolaos Stavrou
2001-01-01
Valuable insight into the theory of disordered systems and spin-glasses has been offered by two classes of exactly solvable models: one-dimensional models and mean-field (infinite-range) ones, which, each carry their own specific techniques and restrictions. Both classes of models are now considered as 'exactly solvable' in the sense that in the thermodynamic limit the partition sum can been carried out analytically and the average over the disorder can be performed using methods which are well understood. In this thesis I study equilibrium properties of spin systems with a combination of one-dimensional short- and infinite-range interactions. I find that such systems, under either synchronous or asynchronous spin dynamics, and even in the absence of disorder, lead to phase diagrams with first-order transitions and regions with a multiple number of locally stable states. I then proceed to the study of recurrent neural network models with (1+∞)-dimensional interactions, and find that the competing short- and long-range forces lead to highly complex phase diagrams and that unlike infinite-range (Hopfield-type) models these phase diagrams depend crucially on the number of patterns stored, even away from saturation. To solve the statics of such models for the case of synchronous dynamics I first make a detour to solve the synchronous counterpart of the one-dimensional random-field Ising model, where I prove rigorously that the physics of the two random-field models (synchronous vs. sequential) becomes asymptotically the same, leading to an extensive ground state entropy and an infinite hierarchy of discontinuous transitions close to zero temperature. Finally, I propose and solve the statics of a spin model for the prediction of secondary structure in random hetero-polymers (which are considered as the natural first step to the study of real proteins). The model lies in the class of (1+∞)-dimensional disordered systems as a consequence of having steric- and hydrogen
Nonlinear acoustic wave propagating in one-dimensional layered system
International Nuclear Information System (INIS)
Yun, Y.; Miao, G.Q.; Zhang, P.; Huang, K.; Wei, R.J.
2005-01-01
The propagation of finite-amplitude plane sound in one-dimensional layered media is studied by the extended method of transfer matrix formalism. For the periodic layered system consisting of two alternate types of liquid, the energy distribution and the phase vectors of the interface vibration are computed and analyzed. It is found that in the pass-band, the second harmonic of sound wave can propagate with the characteristic modulation
First direct observation of time-reversal non-invariance in the neutral-kaon system
Angelopoulos, Angelos; Aslanides, Elie; Backenstoss, Gerhard; Bargassa, P; Behnke, O; Benelli, A; Bertin, V; Blanc, F; Bloch, P; Carlson, P J; Carroll, M; Cawley, E; Chertok, M B; Danielsson, M; Dejardin, M; Derré, J; Ealet, A; Eleftheriadis, C; Faravel, L; Fetscher, W; Fidecaro, Maria; Filipcic, A; Francis, D; Fry, J; Gabathuler, Erwin; Gamet, R; Gerber, H J; Go, A; Haselden, A; Hayman, P J; Henry-Coüannier, F; Hollander, R W; Jon-And, K; Kettle, P R; Kokkas, P; Kreuger, R; Le Gac, R; Leimgruber, F; Mandic, I; Manthos, N; Marel, Gérard; Mikuz, M; Miller, J; Montanet, François; Müller, A; Nakada, Tatsuya; Pagels, B; Papadopoulos, I M; Pavlopoulos, P; Polivka, G; Rickenbach, R; Roberts, B L; Ruf, T; Santoni, C; Schäfer, M; Schaller, L A; Schietinger, T; Schopper, A; Tauscher, Ludwig; Thibault, C; Touchard, F; Touramanis, C; van Eijk, C W E; Vlachos, S; Weber, P; Wigger, O; Wolter, M; Zavrtanik, D; Zimmerman, D
1998-01-01
We report on the first observation of time-reversal symmetry violation through a comparison of the probabilities of $\\bar{K}^0$ transforming into $K^0$ and $K^0$ into $\\bar{K}^0$ as a function of the neutral-kaon eigentime $t$. The comparison is based on the analysis of the neutral-kaon semileptonic decays recorded in the CPLEAR experiment. There, the strangeness of the neutral kaon at time $t=0$ was tagged by the kaon charge in the reaction $p\\bar{p} \\rightarrow K^{\\pm} \\pi^{\\mp} K^0(\\bar{K}^0)$ at rest, whereas the strangeness of the kaon at the decay time $t=\\tau$ was tagged by the lepton charge in the final state. An average decay-rate asymmetry \\begin{equation*} \\langle^{R(\\bar{K}^0_{t=0} \\to e^+\\pi^-\
DEFF Research Database (Denmark)
Wang, Wen; Yan, Lingjie; Zeng, Xiangjun
2017-01-01
Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...
SLG(Single-Line-to-Ground Fault Location in NUGS(Neutral Un-effectively Grounded System
Directory of Open Access Journals (Sweden)
Zhang Wenhai
2018-01-01
Full Text Available This paper reviews the SLG(Single-Line-to-Ground fault location methods in NUGS(Neutral Un-effectively Grounded System, including ungrounded system, resonant grounded system and high-resistance grounded system which are widely used in Northern Europe and China. This type of fault is hard to detect and location because fault current is the sum of capacitance current of the system which is always small(about tens of amperes. The characteristics of SLG fault in NUGS and the fault location methods are introduced in the paper.
A low dimensional dynamical system for the wall layer
Aubry, N.; Keefe, L. R.
1987-01-01
Low dimensional dynamical systems which model a fully developed turbulent wall layer were derived.The model is based on the optimally fast convergent proper orthogonal decomposition, or Karhunen-Loeve expansion. This decomposition provides a set of eigenfunctions which are derived from the autocorrelation tensor at zero time lag. Via Galerkin projection, low dimensional sets of ordinary differential equations in time, for the coefficients of the expansion, were derived from the Navier-Stokes equations. The energy loss to the unresolved modes was modeled by an eddy viscosity representation, analogous to Heisenberg's spectral model. A set of eigenfunctions and eigenvalues were obtained from direct numerical simulation of a plane channel at a Reynolds number of 6600, based on the mean centerline velocity and the channel width flow and compared with previous work done by Herzog. Using the new eigenvalues and eigenfunctions, a new ten dimensional set of ordinary differential equations were derived using five non-zero cross-stream Fourier modes with a periodic length of 377 wall units. The dynamical system was integrated for a range of the eddy viscosity prameter alpha. This work is encouraging.
Exactly integrable analogue of a one-dimensional gravitating system
International Nuclear Information System (INIS)
Miller, Bruce N.; Yawn, Kenneth R.; Maier, Bill
2005-01-01
Exchange symmetry in acceleration partitions the configuration space of an N particle one-dimensional gravitational system (OGS) into N! equivalent cells. We take advantage of the resulting small angular separation between the forces in neighboring cells to construct a related integrable version of the system that takes the form of a central force problem in N-1 dimensions. The properties of the latter, including the construction of trajectories and possible continuum limits, are developed. Dynamical simulation is employed to compare the two models. For some initial conditions, excellent agreement is observed
Bound states of Dipolar Bosons in One-dimensional Systems
DEFF Research Database (Denmark)
G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.
2013-01-01
that in the weakly-coupled limit the inter-tube interaction is similar to a zero-range term with a suitable rescaled strength. This allows us to address the corresponding many-body physics of the system by constructing a model where bound chains with one molecule in each tube are the effective degrees of freedom......We consider one-dimensional tubes containing bosonic polar molecules. The long-range dipole-dipole interactions act both within a single tube and between different tubes. We consider arbitrary values of the externally aligned dipole moments with respect to the symmetry axis of the tubes. The few....... This model can be mapped onto one-dimensional Hamiltonians for which exact solutions are known....
Relativistic collective diffusion in one-dimensional systems
Lin, Gui-Wu; Lam, Yu-Yiu; Zheng, Dong-Qin; Zhong, Wei-Rong
2018-05-01
The relativistic collective diffusion in one-dimensional molecular system is investigated through nonequilibrium molecular dynamics with Monte Carlo methods. We have proposed the relationship among the speed, the temperature, the density distribution and the collective diffusion coefficient of particles in a relativistic moving system. It is found that the relativistic speed of the system has no effect on the temperature, but the collective diffusion coefficient decreases to zero as the velocity of the system approaches to the speed of light. The collective diffusion coefficient is modified as D‧ = D(1 ‑w2 c2 )3 2 for satisfying the relativistic circumstances. The present results may contribute to the understanding of the behavior of the particles transport diffusion in a high speed system, as well as enlighten the study of biological metabolism at relativistic high speed situation.
Rosenberg, Yvonne; Sack, Markus; Montefiori, David; Forthal, Donald; Mao, Lingjun; -Abanto, Segundo Hernandez; Urban, Lori; Landucci, Gary; Fischer, Rainer; Jiang, Xiaoming
2013-01-01
Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs) has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT) of simian/human immunodeficiency virus (SHIV) in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01) or a single chain antibody construct (m9), for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production. PMID:23533588
Directory of Open Access Journals (Sweden)
Yvonne Rosenberg
Full Text Available Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT of simian/human immunodeficiency virus (SHIV in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01 or a single chain antibody construct (m9, for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production.
Three-dimensional wedge filling in ordered and disordered systems
International Nuclear Information System (INIS)
Greenall, M J; Parry, A O; Romero-Enrique, J M
2004-01-01
We investigate interfacial structural and fluctuation effects occurring at continuous filling transitions in 3D wedge geometries. We show that fluctuation-induced wedge covariance relations that have been reported recently for 2D filling and wetting have mean-field or classical analogues that apply to higher-dimensional systems. Classical wedge covariance emerges from analysis of filling in shallow wedges based on a simple interfacial Hamiltonian model and is supported by detailed numerical investigations of filling within a more microscopic Landau-like density functional theory. Evidence is presented that classical wedge covariance is also obeyed for filling in more acute wedges in the asymptotic critical regime. For sufficiently short-ranged forces mean-field predictions for the filling critical exponents and covariance are destroyed by pseudo-one-dimensional interfacial fluctuations. We argue that in this filling fluctuation regime the critical exponents describing the divergence of length scales are related to values of the interfacial wandering exponent ζ(d) defined for planar interfaces in (bulk) two-dimensional (d = 2) and three-dimensional (d = 3) systems. For the interfacial height l w ∼ θ-α) -β w , with θ the contact angle and α the wedge tilt angle, we find β w = ζ(2)/2(1-ζ(3)). For pure systems (thermal disorder) we recover the known result β w = 1/4 predicted by interfacial Hamiltonian studies whilst for random-bond disorder we predict the universal critical exponent β ∼ even in the presence of dispersion forces. We revisit the transfer matrix theory of three-dimensional filling based on an effective interfacial Hamiltonian model and discuss the interplay between breather, tilt and torsional interfacial fluctuations. We show that the coupling of the modes allows the problem to be mapped onto a quantum mechanical problem as conjectured by previous authors. The form of the interfacial height probability distribution function predicted by
Upgrade of the TCV tokamak, first phase: Neutral beam heating system
Energy Technology Data Exchange (ETDEWEB)
Karpushov, Alexander N., E-mail: alexander.karpushov@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Alberti, Stefano; Chavan, René [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Davydenko, Vladimir I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Duval, Basil P. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Ivanov, Alexander A. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Fasel, Damien; Fasoli, Ambrogio [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Gorbovsky, Aleksander I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Goodman, Timothy [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Kolmogorov, Vyacheslav V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Martin, Yves; Sauter, Olivier [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Sorokin, Aleksey V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); and others
2015-10-15
Highlights: • Widening the parameter range of reactor relevant regimes on the TCV tokamak. • Installation of 1 MW, 30 keV neutral beam, direct ion heating, access to T{sub i}/T{sub e} ≥ 1. • ASTRA simulation of plasma response to NB and EC heating in different regimes. • Specific low divergency neutral beam injector with tunable beam power and energy. - Abstract: Experiments on TCV are designed to complement the work at large integrated tokamak facilities (such as JET) to provide a stepwise approach to extrapolation to ITER and DEMO in areas where medium-size tokamaks can often exploit their experimental capabilities and flexibility. Improving the understanding and control requirements of burning plasmas is a major scientific challenge, requiring access to plasma regimes and configurations with high normalized plasma pressure and a wide range of ion to electron temperature ratios, including T{sub e}/T{sub i} ∼ 1. These conditions will be explored by adding a 1 MW neutral heating beam to TCV's auxiliary for direct ion heating (2015) and increasing the ECH power injected in X-mode at the third harmonic (2 MW in 2015–2016). The manufacturing of the neutral beam injector was launched in 2014.
Saturable reactor-controlled power supply system for TCT/TFTR neutral beam sources
International Nuclear Information System (INIS)
Baker, W.R.; Hopkins, D.B.; Dexter, W.L.; Kuenning, R.W.; Smith, B.J.
1975-11-01
Each neutral beam source requires one major power supply, the acceleration supply, and four auxiliary power supplies. The power supplies are designed to permit independent interruption of current to any source and crowbarring within 20 μsec, in the event of a source spark, while not disturbing the normal pulsing of all other adjacent sources. The sources are described
Critical phenomena in quasi-two-dimensional vibrated granular systems.
Guzmán, Marcelo; Soto, Rodrigo
2018-01-01
The critical phenomena associated to the liquid-to-solid transition of quasi-two-dimensional vibrated granular systems is studied using molecular dynamics simulations of the inelastic hard sphere model. The critical properties are associated to the fourfold bond-orientational order parameter χ_{4}, which measures the level of square crystallization of the system. Previous experimental results have shown that the transition of χ_{4}, when varying the vibration amplitude, can be either discontinuous or continuous, for two different values of the height of the box. Exploring the amplitude-height phase space, a transition line is found, which can be either discontinuous or continuous, merging at a tricritical point and the continuous branch ends in an upper critical point. In the continuous transition branch, the critical properties are studied. The exponent associated to the amplitude of the order parameter is β=1/2, for various system sizes, in complete agreement with the experimental results. However, the fluctuations of χ_{4} do not show any critical behavior, probably due to crossover effects by the close presence of the tricritical point. Finally, in quasi-one-dimensional systems, the transition is only discontinuous, limited by one critical point, indicating that two is the lower dimension for having a tricritical point.
Incoherent control and entanglement for two-dimensional coupled systems
International Nuclear Information System (INIS)
Romano, Raffaele; D'Alessandro, Domenico
2006-01-01
We investigate accessibility and controllability of a quantum system S coupled to a quantum probe P, both described by two-dimensional Hilbert spaces, under the hypothesis that the external control affects only P. In this context accessibility and controllability properties describe to what extent it is possible to drive the state of the system S by acting on P and using the interaction between the two systems. We give necessary and sufficient conditions for these properties and we discuss the relation with the entangling capability of the interaction between S and P. In particular, we show that controllability can be expressed in terms of the SWAP and √(SWAP) operators acting on the composite system
Two-dimensional nuclear magnetic resonance of quadrupolar systems
Energy Technology Data Exchange (ETDEWEB)
Wang, Shuanhu [Univ. of California, Berkeley, CA (United States)
1997-09-01
This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.
International Nuclear Information System (INIS)
Kuriyama, M.; Akino, N.; Ebisawa, N.; Honda, A.; Itoh, T.; Kawai, M.; Mogaki, K.; Ohga, T.; Oohara, H.; Umeda, N.; Usui, K.; Yamamoto, M.; Yamamoto, T.; Matsuoka, M.
2002-01-01
The positive-ion based neutral beam injection (NBI) system for JT-60, which consists of 14 beamline units and has a beam energy of 70 to 100 keV, started operation in 1986 with hydrogen beams and injected a neutral beam power of 27 MW at 75 keV into the JT-60 plasma. In 1991, the NBI system was modified to be able to handle deuterium beams as part of the JT-60 upgrade modification. After executing some research and developments, deuterium beams of 40 MW at 95 keV were injected in 1996. As a result, NBI has contributed to the achievement of the highest performance plasmas, a DT-equivalent fusion power gain of 1.25 and a fusion triple product of 1.55 x 10 21 keVs/m 3 , in the world on JT-60U
Shinto, Katsuhiro; Kitajima, Sumio; Kiyama, Satoru; Nishiura, Masaki; Sasao, Mamiko; Sugawara, Hiroshi; Takenaga, Mahoko; Takeuchi, Shu; Wada, Motoi
2005-01-01
For alpha-particle diagnostics in a thermonuclear fusion reactor, neutralization using a fast (~2 MeV) neutral He beam produced by the spontaneous electron detachment of a He- is considered most promising. However, the beam transport of produced fast neutral He has not been studied, because of difficulty for producing high-brightness He- beam. Double-charge-exchange He- sources and simple beam transport systems were developed and their results were reported in the PAC99* and other papers.** To accelerate an intense He- beam and verify the production of the fast neutral He beam, a new test stand has been designed. It consists of a multi-cusp He+
Pattern formation in two-dimensional square-shoulder systems
International Nuclear Information System (INIS)
Fornleitner, Julia; Kahl, Gerhard
2010-01-01
Using a highly efficient and reliable optimization tool that is based on ideas of genetic algorithms, we have systematically studied the pattern formation of the two-dimensional square-shoulder system. An overwhelming wealth of complex ordered equilibrium structures emerge from this investigation as we vary the shoulder width. With increasing pressure three structural archetypes could be identified: cluster lattices, where clusters of particles occupy the sites of distorted hexagonal lattices, lane formation, and compact particle arrangements with high coordination numbers. The internal complexity of these structures increases with increasing shoulder width.
Pattern formation in two-dimensional square-shoulder systems
Energy Technology Data Exchange (ETDEWEB)
Fornleitner, Julia [Institut fuer Festkoerperforschung, Forschungsszentrum Juelich, D-52425 Juelich (Germany); Kahl, Gerhard, E-mail: fornleitner@cmt.tuwien.ac.a [Institut fuer Theoretische Physik and Centre for Computational Materials Science (CMS), Technische Universitaet Wien, Wiedner Hauptstrasse 8-10, A-1040 Wien (Austria)
2010-03-17
Using a highly efficient and reliable optimization tool that is based on ideas of genetic algorithms, we have systematically studied the pattern formation of the two-dimensional square-shoulder system. An overwhelming wealth of complex ordered equilibrium structures emerge from this investigation as we vary the shoulder width. With increasing pressure three structural archetypes could be identified: cluster lattices, where clusters of particles occupy the sites of distorted hexagonal lattices, lane formation, and compact particle arrangements with high coordination numbers. The internal complexity of these structures increases with increasing shoulder width.
Violating Bell inequalities maximally for two d-dimensional systems
International Nuclear Information System (INIS)
Chen Jingling; Wu Chunfeng; Oh, C. H.; Kwek, L. C.; Ge Molin
2006-01-01
We show the maximal violation of Bell inequalities for two d-dimensional systems by using the method of the Bell operator. The maximal violation corresponds to the maximal eigenvalue of the Bell operator matrix. The eigenvectors corresponding to these eigenvalues are described by asymmetric entangled states. We estimate the maximum value of the eigenvalue for large dimension. A family of elegant entangled states |Ψ> app that violate Bell inequality more strongly than the maximally entangled state but are somewhat close to these eigenvectors is presented. These approximate states can potentially be useful for quantum cryptography as well as many other important fields of quantum information
Wave dispersion relations in two-dimensional Yukawa systems
International Nuclear Information System (INIS)
Liu Yanhong; Liu Bin; Chen Yanping; Yang Size; Wang Long; Wang Xiaogang
2003-01-01
Collective modes in a two-dimensional Yukawa system are investigated by molecular dynamics simulation in a wide range of coupling parameter Γ and screening strength κ. The dispersion relations and sound speeds of the transverse and longitudinal waves obtained for hexagonal lattice are in agreement with the theoretical results. The negative dispersion of the longitudinal wave is demonstrated. Frequency gaps are found on the dispersion curves of the transverse wave due to scattering of the waves on lattice defects for proper values of Γ. The common frequency of transverse and longitudinal waves drops dramatically with the increasing screening strength κ
Shape synchronization control for three-dimensional chaotic systems
International Nuclear Information System (INIS)
Huang, Yuanyuan; Wang, Yinhe; Chen, Haoguang; Zhang, Siying
2016-01-01
This paper aims to the three-dimensional continuous chaotic system and shape of the chaotic attractor by utilizing the basic theory of plane curves in classical differential geometry, the continuous controller is synthesized for the master–slave synchronization in shape. This means that the slave system can possess the same shape of state trajectory with the master system via the continuous controller. The continuous controller is composed of three sub-controllers, which respectively correspond to the master–slave synchronization in shape for the three projective curves of the chaotic attractor onto the three coordinate planes. Moreover, the proposed shape synchronization technique as well as application of control scheme to secure communication is also demonstrated in this paper, where numerical simulation results show the proposed control method works well.
Quantum correlation of high dimensional system in a dephasing environment
Ji, Yinghua; Ke, Qiang; Hu, Juju
2018-05-01
For a high dimensional spin-S system embedded in a dephasing environment, we theoretically analyze the time evolutions of quantum correlation and entanglement via Frobenius norm and negativity. The quantum correlation dynamics can be considered as a function of the decoherence parameters, including the ratio between the system oscillator frequency ω0 and the reservoir cutoff frequency ωc , and the different environment temperature. It is shown that the quantum correlation can not only measure nonclassical correlation of the considered system, but also perform a better robustness against the dissipation. In addition, the decoherence presents the non-Markovian features and the quantum correlation freeze phenomenon. The former is much weaker than that in the sub-Ohmic or Ohmic thermal reservoir environment.
A three-dimensional computerized isometric strength measurement system.
Black, Nancy L; Das, Biman
2007-05-01
The three-dimensional Computerized Isometric Strength Measurement System (CISMS) reliably and accurately measures isometric pull and push strengths in work spaces of paraplegic populations while anticipating comparative studies with other populations. The main elements of the system were: an extendable arm, a vertical supporting track, a rotating platform, a force transducer, stability sensors and a computerized data collection interface. The CISMS with minor modification was successfully used to measure isometric push-up and pull-down strengths of paraplegics and isometric push, pull, push-up and pull-down strength in work spaces for seated and standing able-bodied populations. The instrument has satisfied criteria of versatility, safety and comfort, ease of operation, and durability. Results are accurate within 2N for aligned forces. Costing approximately $1,500 (US) including computer, the system is affordable and accurate for aligned isometric strength measurements.
Considerations and calculations for the neutral-injection system in ZEPHYR
International Nuclear Information System (INIS)
Feist, J.H.; Herrmann, W.; Speth, E.
1981-01-01
The heating of the ZEPHYR plasma to ignition temperatures shall be accomplished by neutral injection and subsequent compression of the plasma. 25 MW of neutral power are required. A parametrical study of beam transmission was performed to find limitations on the type and arrangement of sources imposed by the small width of the porthole to the torus and the small height of the plasma target. A reference beam line has been designed and the power transmission calculated as a function of gas flow through the sources. The limitations mentioned make it necessary to design the beam lines as compact as possible to avoid intolerable losses in the duct or power outside the plasma target. Depending on the reliability of a single source, the number of sources that are available in at least 75 % of the discharges has been calculated for different numbers of installed sources. (author)
Relative stability constants of the uranyl tropolonate system with neutral ligands in benzene
Energy Technology Data Exchange (ETDEWEB)
Degetto, S; Baracco, L; Marangoni, G [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Celon, E
1976-01-01
The relative formation constants K*sub(L) of some uranyl tropolonate adducts with neutral ligands L (L = cyclopentanone, pyridine, dimethyl sulphoxide, 4-chloropyridine N-oxide, 4-methylpyridine N-oxide, triphenylphosphine oxide, and triphenylarsine oxide) of general formula (U0/sub 2/(trop)/sub 2/L) (Htrop = tropolone) have been determined spectrophotometrically by studying the equilibria ((UO/sub 2/(trop)/sub 2/)/sub 2/) + 2L = 2 (UO/sub 2/(trop)/sub 2/L) in the benzene at 25/sup 0/C. The K*sub(L) sequence obtained can be used as a quantitative scale of donor ability of the various neutral ligands toward the common substrate. Other attempted qualitative correlations based on i.r., /sup 1/H n.m.r., and thermal measurements are compared and discussed.
International Nuclear Information System (INIS)
Breus, T.K.; Krymskij, A.M.; Mitnitskij, V.Ya.
1987-01-01
Numeric modelling of the Venus flow-around by the solar wind with regard to stream loading by heavy ions, produced under photoionization of the Venus neutral oxygen corona, is conducted. It is shown, that this effect can account for a whole number of peculiarities related to the solar wind interaction with the planet which have not been clearly explained yet, namely, shock wave position, solar wind stream and magnetic field characteristics behind the front
Microwave plasma source for neutral-beam injection systems. Quarterly technical progress report
International Nuclear Information System (INIS)
1981-01-01
The overall program is described and the technical and programmatic reasons for the decision to pursue both the RFI and ECH sources into the current hydrogen test stage is discussed. We consider the general characteristics of plasma sources in the parameter regime of interest for neutral beam applications. The operatonal characteristics, advantages and potential problems of RFI and ECH sources are discussed. In these latter two sections we rely heavily on experience derived from developing RFI and ECH ion engine sources for NASA
International Nuclear Information System (INIS)
Paterson, J.A.; Biagi, L.A.; Fong, M.; Koehler, G.W.; Low, W.; Purgalis, P.; Wells, R.P.
1983-12-01
The Neutral Beam Engineering Test Facility (NBETF) at Lawrence Berkeley Laboratory (LBL) is a National Test Facility used to develop long pulse Neutral Beam Sources. The Facility will test sources up to 120 keV, 50 A, with 30 s beam-on times with a 10% duty factor. For this application, an actively cooled beam dump is required and one has been constructed capable of dissipating a wide range of power density profiles. The flexibility of the design is achieved by utilizing a standard modular panel design which is incorporated into a moveable support structure comprised of eight separately controllable manipulator assemblies. A unique neutralizer design has been installed into the NBETF beamline. This is a gun-drilled moveable brazed assembly which provides continuous armoring of the beamline near the source. The unit penetrates the source mounting valve during operation and retracts to permit the valve to close as needed. The beamline is also equpped with many beam scraper plates of differing detail design and dissipation capabilities
International Nuclear Information System (INIS)
Cordier, J.J.; Bayetti, P.; Hemsworth, R.; David, O.; Friconneau, J.P.
2007-01-01
Remote handling (R/H) maintenance of ITER components is one of the main challenges of the ITER project. This type of maintenance shall be operational for the assembly and nuclear phase of exploitation of ITER. It must be considered at a very early stage since it significantly impacts on the components design, interfaces management, assembly, maintenance and integration aspects. A large part of the R/H equipment will be procured by the EU Participating Team, including the whole Neutral Beam R/H Equipment. The Neutral Beam Heating and Current Drive system (NB and CD) design is being revisited by the ITER project. A vertical maintenance scheme is presently considered which may significantly impact on the reference design and associated components and lead to a new design of the NB and CD vacuum tank. In addition, NB line components remote handling solutions are being studied. The neutral beam test facility ITER to be built in Europe in the near future is also based on the vertical NB maintenance scheme of beam line components. New design guidelines compliant for both the ITER NB and CD system and the NB test facility proposed by the CEA association are described in the paper
Directory of Open Access Journals (Sweden)
D. A. Fetisov
2015-01-01
Full Text Available The controllability conditions are well known if we speak about linear stationary systems: a linear stationary system is controllable if and only if the dimension of the state vector is equal to the rank of the controllability matrix. The concept of the controllability matrix is extended to affine systems, but relations between affine systems controllability and properties of this matrix are more complicated. Various controllability conditions are set for affine systems, but they deal as usual either with systems of some special form or with controllability in some small neighborhood of the concerned point. An affine system is known to be controllable if the system is equivalent to a system of a canonical form, which is defined and regular in the whole space of states. In this case, the system is said to be feedback linearizable in the space of states. However there are examples, which illustrate that a system can be controllable even if it is not feedback linearizable in any open subset in the space of states. In this article we deal with such systems.Affine systems with two-dimensional control are considered. The system in question is assumed to be equivalent to a system of a quasicanonical form with two-dimensional zero dynamics which is defined and regular in the whole space of states. Therefore the controllability of the original system is equivalent to the controllability of the received system of a quasicanonical form. In this article the sufficient condition for an available solution of the terminal problem is proven for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. The condition is valid in the case of an arbitrary time interval and arbitrary initial and finite states of the system. Therefore the controllability condition is set for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. An example is given which illustrates how the proved
High-Dimensional Adaptive Particle Swarm Optimization on Heterogeneous Systems
International Nuclear Information System (INIS)
Wachowiak, M P; Sarlo, B B; Foster, A E Lambe
2014-01-01
Much work has recently been reported in parallel GPU-based particle swarm optimization (PSO). Motivated by the encouraging results of these investigations, while also recognizing the limitations of GPU-based methods for big problems using a large amount of data, this paper explores the efficacy of employing other types of parallel hardware for PSO. Most commodity systems feature a variety of architectures whose high-performance capabilities can be exploited. In this paper, high-dimensional problems and those that employ a large amount of external data are explored within the context of heterogeneous systems. Large problems are decomposed into constituent components, and analyses are undertaken of which components would benefit from multi-core or GPU parallelism. The current study therefore provides another demonstration that ''supercomputing on a budget'' is possible when subtasks of large problems are run on hardware most suited to these tasks. Experimental results show that large speedups can be achieved on high dimensional, data-intensive problems. Cost functions must first be analysed for parallelization opportunities, and assigned hardware based on the particular task
Energy Current Cumulants in One-Dimensional Systems in Equilibrium
Dhar, Abhishek; Saito, Keiji; Roy, Anjan
2018-06-01
A recent theory based on fluctuating hydrodynamics predicts that one-dimensional interacting systems with particle, momentum, and energy conservation exhibit anomalous transport that falls into two main universality classes. The classification is based on behavior of equilibrium dynamical correlations of the conserved quantities. One class is characterized by sound modes with Kardar-Parisi-Zhang scaling, while the second class has diffusive sound modes. The heat mode follows Lévy statistics, with different exponents for the two classes. Here we consider heat current fluctuations in two specific systems, which are expected to be in the above two universality classes, namely, a hard particle gas with Hamiltonian dynamics and a harmonic chain with momentum conserving stochastic dynamics. Numerical simulations show completely different system-size dependence of current cumulants in these two systems. We explain this numerical observation using a phenomenological model of Lévy walkers with inputs from fluctuating hydrodynamics. This consistently explains the system-size dependence of heat current fluctuations. For the latter system, we derive the cumulant-generating function from a more microscopic theory, which also gives the same system-size dependence of cumulants.
Muon studies of low-dimensional solid state systems
International Nuclear Information System (INIS)
Jestaedt, T.
1999-04-01
This thesis concerns the use of the technique of μSR, an abbreviation which stands for three separate types of experiments: muon spin rotation, muon spin relaxation and muon spin resonance. The experiments presented here were performed on beamlines at the ISIS facility at the Rutherford Appleton Laboratory (UK) and at the Paul Scherrer Institut (Villigen, Switzerland). The systems studied are linked by the common theme of reduced dimensionality. Results of μSR measurements on La 2-x Sr x NiO 4+δ (nickelates) are presented. In these systems the lattice constants are much smaller in two of the dimensions as compared to the third, leading to two dimensional magnetism. Earlier experiments using techniques other than μSR concentrated mainly on materials with x = 0 and δ ≠ 0. The work that I describe on La 2-x Sr x NiO 4+δ shows that, there are interesting magnetic features as a function of strontium doping, and the details of this dependence are examined. In each of the samples oscillations of the muon spin polarization were observed below a sample dependent temperature, showing that low temperature magnetic order occurs. μSR is also used to study Sr 2 LnMn 2 O 7 (the Ruddlesden- Popper phases), where Ln are various ions of the lanthanide series. These manganates have a layered structure, leading to a reduced dimensionality as compared to the related perovskite compounds of the MnO 3 series. Like the doped MnO 3 compounds, some of the Ruddlesden-Popper phases exhibit colossal magnetoresistance (CMR), all effect which initially stirred interest in the MnO 3 systems. In contrast to the MnO 3 systems, the relevant Mn 2 O 7 materials show this CMR effect over an extended temperature range. The μSR work is consistent with the existence of magnetic clusters in some of the Mn 2 O 7 materials and these clusters appear to be associated with the observation of CMR. The compound CaV 4 O 9 is the first known two-dimensional compound to exhibit a spin-gap and the effects
Growing B Lymphocytes in a Three-Dimensional Culture System
Wu, J. H. David; Bottaro, Andrea
2010-01-01
A three-dimensional (3D) culture system for growing long-lived B lymphocytes has been invented. The capabilities afforded by the system can be expected to expand the range of options for immunological research and related activities, including testing of immunogenicity of vaccine candidates in vitro, generation of human monoclonal antibodies, and immunotherapy. Mature lymphocytes, which are the effectors of adaptive immune responses in vertebrates, are extremely susceptible to apoptotic death, and depend on continuous reception of survival-inducing stimulation (in the forms of cytokines, cell-to-cell contacts, and antigen receptor signaling) from the microenvironment. For this reason, efforts to develop systems for long-term culture of functional, non-transformed and non-activated mature lymphocytes have been unsuccessful until now. The bone-marrow microenvironment supports the growth and differentiation of many hematopoietic lineages, in addition to B-lymphocytes. Primary bone-marrow cell cultures designed to promote the development of specific cell types in vitro are highly desirable experimental systems, amenable to manipulation under controlled conditions. However, the dynamic and complex network of stromal cells and insoluble matrix proteins is disrupted in prior plate- and flask-based culture systems, wherein the microenvironments have a predominantly two-dimensional (2D) character. In 2D bone-marrow cultures, normal B-lymphoid cells become progressively skewed toward precursor B-cell populations that do not retain a normal immunophenotype, and such mature B-lymphocytes as those harvested from the spleen or lymph nodes do not survive beyond several days ex vivo in the absence of mitogenic stimulation. The present 3D culture system is a bioreactor that contains highly porous artificial scaffolding that supports the long-term culture of bone marrow, spleen, and lymph-node samples. In this system, unlike in 2D culture systems, B-cell subpopulations developing
Spin precession in inversion-asymmetric two-dimensional systems
International Nuclear Information System (INIS)
Liu, M.-H.; Chang, C.-R.
2006-01-01
We present a theoretical method to calculate the expectation value of spin in an inversion-asymmetric two-dimensional (2D) system with respect to an arbitrarily spin-polarized electron state, injected via an ideal point contact. The 2D system is confined in a [0 0 1]-grown quantum well, where both the Rashba and the Dresselhaus spin-orbit couplings are taken into account. The obtained analytical results allow more concrete description of the spatial behaviors of the spin precession caused individually by the Rashba and the Dresselhaus terms. Applying the calculation on the Datta-Das spin-FET, whose original design considers only the Rashba effect inside the channel, we investigate the possible influence due to the Dresselhaus spin-orbit coupling. Concluded solution is the choice of ±[1±10], in particular [1 1 0], as the channel direction
A Three-Dimensional Cooperative Guidance Law of Multimissile System
Directory of Open Access Journals (Sweden)
Xing Wei
2015-01-01
Full Text Available In order to conduct saturation attacks on a static target, the cooperative guidance problem of multimissile system is researched. A three-dimensional guidance model is built using vector calculation and the classic proportional navigation guidance (PNG law is extended to three dimensions. Based on this guidance law, a distributed cooperative guidance strategy is proposed and a consensus protocol is designed to coordinate the time-to-go commands of all missiles. Then an expert system, which contains two extreme learning machines (ELM, is developed to regulate the local proportional coefficient of each missile according to the command. All missiles can arrive at the target simultaneously under the assumption that the multimissile network is connected. A simulation scenario is given to demonstrate the validity of the proposed method.
Quantum key distribution for composite dimensional finite systems
Shalaby, Mohamed; Kamal, Yasser
2017-06-01
The application of quantum mechanics contributes to the field of cryptography with very important advantage as it offers a mechanism for detecting the eavesdropper. The pioneering work of quantum key distribution uses mutually unbiased bases (MUBs) to prepare and measure qubits (or qudits). Weak mutually unbiased bases (WMUBs) have weaker properties than MUBs properties, however, unlike MUBs, a complete set of WMUBs can be constructed for systems with composite dimensions. In this paper, we study the use of weak mutually unbiased bases (WMUBs) in quantum key distribution for composite dimensional finite systems. We prove that the security analysis of using a complete set of WMUBs to prepare and measure the quantum states in the generalized BB84 protocol, gives better results than using the maximum number of MUBs that can be constructed, when they are analyzed against the intercept and resend attack.
Magnon damping in two-dimensional Heisenberg ferromagnetic system
International Nuclear Information System (INIS)
Cheng, T.-M.; Li Lin; Ze Xianyu
2006-01-01
A magnon-phonon interaction model is set up for a two-dimensional insulating ferromagnetic system. By using Matsubara function theory we have studied the magnon damping -I m Σ* (1) (k->) and calculated the magnon damping -I m Σ* (1) (k->) curve on the main symmetric point and line in the Brillouin zone for various parameters in the system. It is concluded that at the boundary of Brillouin zone there is a strong magnon damping. However, the magnon damping is very weak on the zone of small wave vector and the magnon damping reaches maximal value at very low temperature. The contributions of longitudinal phonon and transverse phonon on the magnon damping are compared and the influences of various parameters are also discussed
On the partition function of d+1 dimensional kink-bearing systems
International Nuclear Information System (INIS)
Radosz, A.; Salejda, W.
1987-01-01
It is suggested that the problem of finding a partition function of d+1 dimensional kink-bearing system in the classical approximation may be formulated as an eigenvalue problem of an appropriate d dimensional quantum
Nonlinear transport behavior of low dimensional electron systems
Zhang, Jingqiao
The nonlinear behavior of low-dimensional electron systems attracts a great deal of attention for its fundamental interest as well as for potentially important applications in nanoelectronics. In response to microwave radiation and dc bias, strongly nonlinear electron transport that gives rise to unusual electron states has been reported in two-dimensional systems of electrons in high magnetic fields. There has also been great interest in the nonlinear response of quantum ballistic constrictions, where the effects of quantum interference, spatial dispersion and electron-electron interactions play crucial roles. In this thesis, experimental results of the research of low dimensional electron gas systems are presented. The first nonlinear phenomena were observed in samples of highly mobile two dimensional electrons in GaAs heavily doped quantum wells at different magnitudes of DC and AC (10 KHz to 20 GHz) excitations. We found that in the DC excitation regime the differential resistance oscillates with the DC current and external magnetic field, similar behavior was observed earlier in AlGaAs/GaAs heterostructures [C.L. Yang et al. ]. At external AC excitations the resistance is found to be also oscillating as a function of the magnetic field. However the form of the oscillations is considerably different from the DC case. We show that at frequencies below 100 KHz the difference is a result of a specific average of the DC differential resistance during the period of the external AC excitations. Secondly, in similar samples, strong suppression of the resistance by the electric field is observed in magnetic fields at which the Landau quantization of electron motion occurs. The phenomenon survives at high temperatures at which the Shubnikov de Haas oscillations are absent. The scale of the electric fields essential for the effect, is found to be proportional to temperature in the low temperature limit. We suggest that the strong reduction of the longitudinal resistance
International Nuclear Information System (INIS)
Zhang Jian; Huang Yiyun; Liu Baohua; Guo Wenjun; Shen Xiaoling; Wei Wei
2011-01-01
A high voltage power supply system has been developed for the diagnostic neutral beam on the HT-7 experimental Tokamak, and the over-voltage phenomenon of storage capacitor was founded in the experiment. In order to analyse and resolve this problem, the structure and principle of high voltage power supply is described and the primary high voltage charging power supply system is introduced in detail. The phenomenon of over-voltage on the capacitors is also studied with circuit model, and the conclusion is obtained that the leakage inductance is the mA in reason which causes the over-voltage on the capacitors. (authors)
Joya, Khurram Saleem
2014-06-04
Neutral HCO3 -/CO2 is a new electrolyte system for in situ generation of robust and efficient Co-derived (Co-Ci) water oxidation electrocatalysts. The Co-Ci/indium tin oxide system shows a remarkable 2.0 mA cm-2 oxygen evolution current density that is sustained for several hours. 7.5 nmol of electroactive species per cm2 generates about 109 μmol of O2 at a rate of 0.51 per mol of catalyst per second.
International Nuclear Information System (INIS)
Fumelli, M.; Jequier, F.; Pamela, J.
1988-01-01
A passive protection system against high voltage vacuum breakdowns has been developed. This system is based on the principle of oscillatory discharges in an RLC circuit coupled with the use of a diode. It allows the interruption of a vacuum breakdown in a few milliseconds. This study has been made for protecting some parts of the neutral beam injectors of the Tore Supra Tokamak experiment, but its field of application should be quite large. The conception of the whole high voltage electrical circuit developed for the Tore Supra injector prototype experiments is also presented
Joya, Khurram Saleem; Takanabe, Kazuhiro; De Groot, Huub J M
2014-01-01
Neutral HCO3 -/CO2 is a new electrolyte system for in situ generation of robust and efficient Co-derived (Co-Ci) water oxidation electrocatalysts. The Co-Ci/indium tin oxide system shows a remarkable 2.0 mA cm-2 oxygen evolution current density that is sustained for several hours. 7.5 nmol of electroactive species per cm2 generates about 109 μmol of O2 at a rate of 0.51 per mol of catalyst per second.
[Three dimensional CT reconstruction system on a personal computer].
Watanabe, E; Ide, T; Teramoto, A; Mayanagi, Y
1991-03-01
A new computer system to produce three dimensional surface image from CT scan has been invented. Although many similar systems have been already developed and reported, they are too expensive to be set up in routine clinical services because most of these systems are based on high power mini-computer systems. According to the opinion that a practical 3D-CT system should be used in daily clinical activities using only a personal computer, we have transplanted the 3D program into a personal computer working in MS-DOS (16-bit, 12 MHz). We added to the program a routine which simulates surgical dissection on the surface image. The time required to produce the surface image ranges from 40 to 90 seconds. To facilitate the simulation, we connected a 3D system with the neuronavigator. The navigator gives the position of the surgical simulation when the surgeon places the navigator tip on the patient's head thus simulating the surgical excision before the real dissection.
International Nuclear Information System (INIS)
Drevillon, B.; Borenstein, S.; Chaurand, B.; Gago, J.M.; Salmeron, R.A.; Borg, A.; Denegri, D.; Pons, Y.; Spiro, M.; Comber, C.; Paler, K.; Tovey, S.N.; Shah, T.P.
1975-01-01
A partial wave analysis of spin-parity of the (antikaon-neutral π + π - ) system in the mass range M(antikaon-neutral π + π - ) - and 1 + states is found, the unatural spin-parity accounting for more than 3/4 of the events at 3.95GeV/c and for more than half at 14.3GeV/c. Natural parity exchange is dominant at both energies. A fit of the cross sections of several states to Psub(lab)sup(-n) gives n between 1.5 and 2.0 [fr
Balkányi, László
2002-01-01
To develop information systems (IS) in the changing environment of the health sector, a simple but throughout model, avoiding the techno-jargon of informatics, might be useful for the top management. A platform neutral, extensible, transparent conceptual model should be established. Limitations of current methods lead to a simple, but comprehensive mapping, in the form of a three-dimensional cube. The three 'orthogonal' views are (a) organization functionality, (b) organizational structures and (c) information technology. Each of the cube-sides is described according to its nature. This approach enables to define any kind of an IS component as a certain point/layer/domain of the cube and enables also the management to label all IS components independently form any supplier(s) and/or any specific platform. The model handles changes in organization structure, business functionality and the serving info-system independently form each other. Practical application extends to (a) planning complex, new ISs, (b) guiding development of multi-vendor, multi-site ISs, (c) supporting large-scale public procurement procedures and the contracting, implementation phase by establishing a platform neutral reference, (d) keeping an exhaustive inventory of an existing large-scale system, that handles non-tangible aspects of the IS.
Beam-plasma instability in ion beam systems used in neutral beam generation
International Nuclear Information System (INIS)
Hooper, E.B. Jr.
1977-02-01
The beam-plasma instability is analyzed for the ion beams used for neutral beam generation. Both positive and negative ion beams are considered. Stability is predicted when the beam velocity is less than the electron thermal velocity; the only exception occurs when the electron density accompanying a negative ion beam is less than the ion density by nearly the ratio of electron to ion masses. For cases in which the beam velocity is greater than the electron thermal velocity, instability is predicted near the electron plasma frequency
CPLEAR experiment at CERN: Measurement of CP, T and CPT in the neutral kaon system
International Nuclear Information System (INIS)
Adler, R.; Backenstoss, G.; Eckart, B.; Felder, C.; Leimgruber, F.; Pavlopoulos, P.; Polivka, G.; Rickenbach, R.; Santoni, C.; Schietinger, T.; Tauscher, L.; Vlachos, S.; Angelopoulos, A.; Apostolakis, A.; Sakeliou, L.; Aslanides, E.; Bertin, V.; Ealet, A.; Fassnacht, P.; Henry-Couannier, F.
1997-01-01
Using strangeness tagging at production time, CPLEAR measures K 0 /K-bar 0 time-dependent asymmetries in pionic and semileptonic kaon decays. From those, a set of parameters describing CP, T and CPT violation in neutral kaon mixing and decay can be determined. Strangeness tagging at decay time with the lepton charge allows for time-reversal violation to be directly observed with a significance of more than three standard deviations. The precision on each of the CPT violation parameters is discussed. The mass equality of the K 0 and K-bar 0 is tested within 4.x10 -19 GeV
International Nuclear Information System (INIS)
Paschos, E.A.
1977-01-01
It is stated that over the past few years considerable progress has been made in the field of weak interactions. The existence of neutral currents involving leptons and hadrons has been established and some of the questions concerning their detailed structure have been answered. This imposes constraints on the gauge theories and has eliminated large classes of models. New questions have also been raised, one of which concerns the conservation laws obeyed by neutral currents. The wide range of investigations is impressive and is expected to continue with new results from particle, nuclear, and atomic physics. Headings include - various aspects of a gauge theory (choice of group, the symmetry breaking scheme, representation assignments for fermion fields); space-time structure; isospin structure; leptonic neutral currents; and atomic experiments. (U.K.)
Three-dimensional modeler for animated images display system
International Nuclear Information System (INIS)
Boubekeur, Rania
1987-01-01
The mv3d software allows the modeling and display of three dimensional objects in interpretative mode with animation possibility in real time. This system is intended for a graphical extension of a FORTH interpreter (implemented by CEA/IRDI/D.LETI/DEIN) in order to control a specific hardware (3.D card designed and implemented by DEIN) allowing the generation of three dimensional objects. The object description is carried out with a specific graphical language integrated in the FORTH interpreter. Objects are modeled using elementary solids called basic forms (cube, cone, cylinder...) assembled with classical geometric transformations (rotation, translation and scaling). These basic forms are approximated by plane polygonal facets further divided in triangles. Coordinates of the summits of triangles constitute the geometrical data. These are sent to the 3.D. card for processing and display. Performed processing are: geometrical transformations on display, hidden surface elimination, shading and clipping. The mv3d software is not an entire modeler but a simple, modular and extensible tool, to which other specific functions may be easily added such as: robots motion, collisions... (author) [fr
Four-dimensional maps of the human somatosensory system.
Avanzini, Pietro; Abdollahi, Rouhollah O; Sartori, Ivana; Caruana, Fausto; Pelliccia, Veronica; Casaceli, Giuseppe; Mai, Roberto; Lo Russo, Giorgio; Rizzolatti, Giacomo; Orban, Guy A
2016-03-29
A fine-grained description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. Limitations in spatial and temporal resolution of available noninvasive recording and imaging techniques have hindered so far the acquisition of precise, comprehensive four-dimensional maps of human neural activity. The present study combines anatomical and functional data from intracerebral recordings of nearly 100 patients, to generate highly resolved four-dimensional maps of human cortical processing of nonpainful somatosensory stimuli. These maps indicate that the human somatosensory system devoted to the hand encompasses a widespread network covering more than 10% of the cortical surface of both hemispheres. This network includes phasic components, centered on primary somatosensory cortex and neighboring motor, premotor, and inferior parietal regions, and tonic components, centered on opercular and insular areas, and involving human parietal rostroventral area and ventral medial-superior-temporal area. The technique described opens new avenues for investigating the neural basis of all levels of cortical processing in humans.
Neutralized transport experiment
International Nuclear Information System (INIS)
Roy, P.K.; Yu, S.S.; Eylon, S.; Henestroza, E.; Anders, A.; Gilson, E.P.; Bieniosek, F.M.; Greenway, W.G.; Logan, B.G.; Waldron, W.L.; Shuman, D.B.; Vanecek, D.L.; Welch, D.R.; Rose, D.V.; Thoma, C.; Davidson, R.C.; Efthimion, P.C.; Kaganovich, I.; Sefkow, A.B.; Sharp, W.M.
2005-01-01
Experimental details on providing active neutralization of high brightness ion beam have been demonstrated for Heavy Ion Fusion program. A K + beam was extracted from a variable-perveance injector and transported through 2.4 m long quadrupole lattice for final focusing. Neutralization was provided by a localized cathode arc plasma plug and a RF volume plasma system. Effects of beam perveance, emittance, convergence focusing angle, and axial focusing position on neutralization have been investigated. Good agreement has been observed with theory and experiment throughout the study
Three-dimensional measurement system for crime scene documentation
Adamczyk, Marcin; Hołowko, Elwira; Lech, Krzysztof; Michoński, Jakub; MÄ czkowski, Grzegorz; Bolewicki, Paweł; Januszkiewicz, Kamil; Sitnik, Robert
2017-10-01
Three dimensional measurements (such as photogrammetry, Time of Flight, Structure from Motion or Structured Light techniques) are becoming a standard in the crime scene documentation process. The usage of 3D measurement techniques provide an opportunity to prepare more insightful investigation and helps to show every trace in the context of the entire crime scene. In this paper we would like to present a hierarchical, three-dimensional measurement system that is designed for crime scenes documentation process. Our system reflects the actual standards in crime scene documentation process - it is designed to perform measurement in two stages. First stage of documentation, the most general, is prepared with a scanner with relatively low spatial resolution but also big measuring volume - it is used for the whole scene documentation. Second stage is much more detailed: high resolution but smaller size of measuring volume for areas that required more detailed approach. The documentation process is supervised by a specialised application CrimeView3D, that is a software platform for measurements management (connecting with scanners and carrying out measurements, automatic or semi-automatic data registration in the real time) and data visualisation (3D visualisation of documented scenes). It also provides a series of useful tools for forensic technicians: virtual measuring tape, searching for sources of blood spatter, virtual walk on the crime scene and many others. In this paper we present our measuring system and the developed software. We also provide an outcome from research on metrological validation of scanners that was performed according to VDI/VDE standard. We present a CrimeView3D - a software-platform that was developed to manage the crime scene documentation process. We also present an outcome from measurement sessions that were conducted on real crime scenes with cooperation with Technicians from Central Forensic Laboratory of Police.
International Nuclear Information System (INIS)
Lien, C.-H.
2007-01-01
This article considers non-fragile guaranteed cost control problem for a class of uncertain neutral system with time-varying delays in both state and control input. Delay-dependent criteria are proposed to guarantee the robust stabilization of systems. Linear matrix inequality (LMI) optimization approach is used to solve the non-fragile guaranteed cost control problem. Non-fragile guaranteed cost control for unperturbed neutral system is considered in the first step. Robust non-fragile guaranteed cost control for uncertain neutral system is designed directly from the unperturbed condition. An efficient approach is proposed to design the non-fragile guaranteed cost control for uncertain neutral systems. LMI toolbox of Matlab is used to implement the proposed results. Finally, a numerical example is illustrated to show the usefulness of the proposed results
Three-dimensional alginate spheroid culture system of murine osteosarcoma.
Akeda, Koji; Nishimura, Akinobu; Satonaka, Haruhiko; Shintani, Ken; Kusuzaki, Katsuyuki; Matsumine, Akihiko; Kasai, Yuichi; Masuda, Koichi; Uchida, Atsumasa
2009-11-01
Osteosarcoma (OS) is the most common primary malignant tumor of the bone and often forms pulmonary metastases, which are the most important prognostic factor. For further elucidation of the mechanism underlying the progression and metastasis of human OS, a culture system mimicking the microenvironment of the tumor in vivo is needed. We report a novel three-dimensional (3D) alginate spheroid culture system of murine osteosarcoma. Two different metastatic clones, the parental Dunn and its derivative line LM8, which has a higher metastatic potential to the lungs, were encapsulated in alginate beads to develop the 3D culture system. The beads containing murine OS cells were also transplanted into mice to determine their metastatic potential in vivo. In this culture system, murine OS cells encapsulated in alginate beads were able to grow in a 3D structure with cells detaching from the alginate environment. The number of detaching cells was higher in the LM8 cell line than the Dunn cell line. In the in vivo alginate bead transplantation model, the rate of pulmonary metastasis was higher with LM8 cells compared with that of Dunn cells. The cell characteristics and kinetics in this culture system closely reflect the original malignant potential of the cells in vivo.
International Nuclear Information System (INIS)
Aubert, B.
1994-11-01
The evidence for the existence of weak neutral current has been a very controverted topics in the early 1970's, as well as the muon did in the 1930's. The history is very rich considering the evolution of the experimental techniques in high energy particle physics. The history of the discovery and the study of weak neutral current is reviewed. Later the quest of the intermediate vector boson continues with the decision of the community to build a large proton antiproton collider. (K.A.). 14 refs., 1 fig
INTRODUCTION: Physics of Low-dimensional Systems: Nobel Symposium 73
Lundqvist, Stig
1989-01-01
The physics of low-dimensional systems has developed in a remarkable way over the last decade and has accelerated over the last few years, in particular because of the discovery of the new high temperature superconductors. The new developments started more than fifteen years ago with the discovery of the unexpected quasi-one-dimensional character of the TTF-TCNQ. Since then the field of conducting quasi-one-dimensional organic systems have been rapidly growing. Parallel to the experimental work there has been an important theoretical development of great conceptual importance, such as charge density waves, soliton-like excitations, fractional charges, new symmetry properties etc. A new field of fundamental importance was the discovery of the Quantum Hall Effect in 1980. This field is still expanding with new experimental and theoretical discoveries. In 1986, then, came the totally unexpected discovery of high temperature superconductivity which started an explosive development. The three areas just mentioned formed the main themes of the Symposium. They do not in any way exhaust the progress in low-dimensional physics. We should mention the recent important development with both two-dimensional and one-dimensional and even zero-dimensional structures (quantum dots). The physics of mesoscopic systems is another important area where the low dimensionality is a key feature. Because of the small format of this Symposium we could unfortunately not cover these areas. A Nobel Symposium provides an excellent opportunity to bring together a group of prominent scientists for a stimulating exchange of new ideas and results. The Nobel Symposia are very small meetings by invitation only and the number of key international participants is typically in the range 25-40. These Symposia are arranged through a special Nobel Symposium Committee after proposal from individuals. This Symposium was sponsored by the Nobel Foundation through its Nobel Symposium Fund with grants from The
Guo, Kun; Chen, Xin; Freguia, Stefano; Donose, Bogdan C
2013-09-15
This study introduces a novel and simple method to covalently graft neutral red (NR) onto carbon surfaces based on spontaneous reduction of in situ generated NR diazonium salts. Immobilization of neutral red on carbon surface was achieved by immersing carbon electrodes in NR-NaNO2-HCl solution. The functionalized electrodes were characterized by cyclic voltammetry (CV), atomic force microscope (AFM), and X-ray photoelectron spectroscopy (XPS). Results demonstrated that NR attached in this way retains high electrochemical activity and proved that NR was covalently bound to the carbon surface via the pathway of reduction of aryl diazonium salts. The NR-modified electrodes showed a good stability when stored in PBS solution in the dark. The current output of an acetate-oxidising microbial bioanode made of NR-modified graphite felts were 3.63±0.36 times higher than the unmodified electrodes, which indicates that covalently bound NR can act as electron transfer mediator to facilitate electron transfer from bacteria to electrodes. Copyright © 2013 Elsevier B.V. All rights reserved.
Larsen, Tove A
2015-12-15
CO2-neutral wastewater treatment plants can be obtained by improving the recovery of internal wastewater energy resources (COD, nutrients, energy) and reducing energy demand as well as direct emissions of the greenhouse gases N2O and CH4. Climate-friendly wastewater management also includes the management of the heat resource, which is most efficiently recovered at the household level, and robust wastewater management must be able to cope with a possible resulting temperature decrease. At the treatment plant there is a substantial energy optimization potential, both from improving electromechanical devices and sludge treatment as well as through the implementation of more energy-efficient processes like the mainstream anammox process or nutrient recovery from urine. Whether CO2 neutrality can be achieved depends not only on the actual net electricity production, but also on the type of electricity replaced: the cleaner the marginal electricity the more difficult to compensate for the direct emissions, which can be substantial, depending on the stability of the biological processes. It is possible to combine heat recovery at the household scale and nutrient recovery from urine, which both have a large potential to improve the climate friendliness of wastewater management. Copyright © 2015 Elsevier Ltd. All rights reserved.
One- and zero-dimensional electron systems over liquid helium (Review article)
Kovdrya, Y Z
2003-01-01
Experimental and theoretical investigations of one-dimensional and zero-dimensional electron systems near the liquid helium surface are surveyed. The properties of electron states over the plane surface of liquid helium including thin layers of helium are considered. The methods of realization of one- and zero-dimensional electron systems are discussed, and the results of experimental and theoretical investigations of their properties are given. The experiments with localization processes in a quasi-one-dimensional electron systems on liquid helium are described. The collective effects in one-dimensional and quasi-one-dimensional electron systems are considered, and the point of possible application of low-dimensional electron systems on liquid helium in electron devices and quantum computers is discussed.
Sodium-coupled neutral amino acid (System N/A) transporters of the SLC38 gene family.
Mackenzie, Bryan; Erickson, Jeffrey D
2004-02-01
The sodium-coupled neutral amino acid transporters (SNAT) of the SLC38 gene family resemble the classically-described System A and System N transport activities in terms of their functional properties and patterns of regulation. Transport of small, aliphatic amino acids by System A subtypes (SNAT1, SNAT2, and SNAT4) is rheogenic and pH sensitive. The System N subtypes SNAT3 and SNAT5 also countertransport H(+), which may be key to their operation in reverse, and have narrower substrate profiles than do the System A subtypes. Glutamine emerges as a favored substrate throughout the family, except for SNAT4. The SLC38 transporters undoubtedly play many physiological roles including the transfer of glutamine from astrocyte to neuron in the CNS, ammonia detoxification and gluconeogenesis in the liver, and the renal response to acidosis. Probing their regulation has revealed additional roles, and recent work has considered SLC38 transporters as therapeutic targets in neoplasia.
Resonant scattering induced thermopower in one-dimensional disordered systems
Müller, Daniel; Smit, Wilbert J.; Sigrist, Manfred
2015-05-01
This study analyzes thermoelectric properties of a one-dimensional random conductor which shows localization effects and simultaneously includes resonant scatterers yielding sharp conductance resonances. These sharp features give rise to a distinct behavior of the Seebeck coefficient in finite systems and incorporate the degree of localization as a means to enhance thermoelectric performance, in principle. The model for noninteracting electrons is discussed within the Landauer-Büttiker formalism such that analytical treatment is possible for a wide range of properties, if a special averaging scheme is applied. The approximations in the averaging procedure are tested with numerical evaluations showing good qualitative agreement, with some limited quantitative disagreement. The validity of low-temperature Mott's formula is determined and a good approximation is developed for the intermediate temperature range. In both regimes the intricate interplay between Anderson localization due to disorder and conductance resonances of the disorder potential is analyzed.
Four-dimensional gravity as an almost-Poisson system
Ita, Eyo Eyo
2015-04-01
In this paper, we examine the phase space structure of a noncanonical formulation of four-dimensional gravity referred to as the Instanton representation of Plebanski gravity (IRPG). The typical Hamiltonian (symplectic) approach leads to an obstruction to the definition of a symplectic structure on the full phase space of the IRPG. We circumvent this obstruction, using the Lagrange equations of motion, to find the appropriate generalization of the Poisson bracket. It is shown that the IRPG does not support a Poisson bracket except on the vector constraint surface. Yet there exists a fundamental bilinear operation on its phase space which produces the correct equations of motion and induces the correct transformation properties of the basic fields. This bilinear operation is known as the almost-Poisson bracket, which fails to satisfy the Jacobi identity and in this case also the condition of antisymmetry. We place these results into the overall context of nonsymplectic systems.
Thermoelectric transport in two-dimensional giant Rashba systems
Xiao, Cong; Li, Dingping; Ma, Zhongshui; Niu, Qian
Thermoelectric transport in strongly spin-orbit coupled two-dimensional Rashba systems is studied using the analytical solution of the linearized Boltzmann equation. To highlight the effects of inter-band scattering, we assume point-like potential impurities, and obtain the band-and energy-dependent transport relaxation times. Unconventional transport behaviors arise when the Fermi level lies near or below the band crossing point (BCP), such as the non-Drude electrical conducivity below the BCP, the failure of the standard Mott relation linking the Peltier coefficient to the electrical conductivity near the BCP, the enhancement of diffusion thermopower and figure of merit below the BCP, the zero-field Hall coefficient which is not inversely proportional to and not a monotonic function of the carrier density, the enhanced Nernst coefficient below the BCP, and the enhanced current-induced spin-polarization efficiency.
Anonymous voting for multi-dimensional CV quantum system
International Nuclear Information System (INIS)
Shi Rong-Hua; Xiao Yi; Shi Jin-Jing; Guo Ying; Lee, Moon-Ho
2016-01-01
We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. (paper)
Gauge theory for finite-dimensional dynamical systems
International Nuclear Information System (INIS)
Gurfil, Pini
2007-01-01
Gauge theory is a well-established concept in quantum physics, electrodynamics, and cosmology. This concept has recently proliferated into new areas, such as mechanics and astrodynamics. In this paper, we discuss a few applications of gauge theory in finite-dimensional dynamical systems. We focus on the concept of rescriptive gauge symmetry, which is, in essence, rescaling of an independent variable. We show that a simple gauge transformation of multiple harmonic oscillators driven by chaotic processes can render an apparently ''disordered'' flow into a regular dynamical process, and that there exists a strong connection between gauge transformations and reduction theory of ordinary differential equations. Throughout the discussion, we demonstrate the main ideas by considering examples from diverse fields, including quantum mechanics, chemistry, rigid-body dynamics, and information theory
International Nuclear Information System (INIS)
Fujiwara, Yukio; Hanada, Masaya; Okumura, Yoshikazu; Suzuki, Satoshi; Watanabe, Kazuhiro
2001-01-01
In the engineering design of a negative-ion beam source for a high-power neutral beam injection (NBI) system, one of the most important issues is thermo-mechanical design of acceleration grids for producing several tens of MW ion beams. An acceleration grid for the international thermonuclear experimental reactor-neutral beam injection (ITER-NBI) system will be subjected to the heat loading as high as 1.5 MW. In the present paper, thermo-mechanical characteristics of the acceleration grid for the ITER-NBI system were analyzed. Numerical simulation indicated that maximum aperture-axis displacement of the acceleration grid due to thermal expansion would be about 0.7 mm for the heat loading of 1.5 MW. From the thin lens theory of beam optics, beamlet deflection angle by the aperture-axis displacement was estimated to be about 2 mrad, which is within the requirement of the engineering design of the ITER-NBI system. Numerical simulation also indicated that no melting on the acceleration grid would occur for a heat loading of 1.5 MW, while local plastic deformation would happen. To avoid the plastic deformation, it is necessary to reduce the heat loading onto the acceleration grid to less than 1 MW
Statistical mechanics of complex neural systems and high dimensional data
International Nuclear Information System (INIS)
Advani, Madhu; Lahiri, Subhaneil; Ganguli, Surya
2013-01-01
Recent experimental advances in neuroscience have opened new vistas into the immense complexity of neuronal networks. This proliferation of data challenges us on two parallel fronts. First, how can we form adequate theoretical frameworks for understanding how dynamical network processes cooperate across widely disparate spatiotemporal scales to solve important computational problems? Second, how can we extract meaningful models of neuronal systems from high dimensional datasets? To aid in these challenges, we give a pedagogical review of a collection of ideas and theoretical methods arising at the intersection of statistical physics, computer science and neurobiology. We introduce the interrelated replica and cavity methods, which originated in statistical physics as powerful ways to quantitatively analyze large highly heterogeneous systems of many interacting degrees of freedom. We also introduce the closely related notion of message passing in graphical models, which originated in computer science as a distributed algorithm capable of solving large inference and optimization problems involving many coupled variables. We then show how both the statistical physics and computer science perspectives can be applied in a wide diversity of contexts to problems arising in theoretical neuroscience and data analysis. Along the way we discuss spin glasses, learning theory, illusions of structure in noise, random matrices, dimensionality reduction and compressed sensing, all within the unified formalism of the replica method. Moreover, we review recent conceptual connections between message passing in graphical models, and neural computation and learning. Overall, these ideas illustrate how statistical physics and computer science might provide a lens through which we can uncover emergent computational functions buried deep within the dynamical complexities of neuronal networks. (paper)
Five-dimensional ultrasound system for soft tissue visualization.
Deshmukh, Nishikant P; Caban, Jesus J; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M
2015-12-01
A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information. We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time. We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom. A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.
A qualitative numerical study of high dimensional dynamical systems
Albers, David James
Since Poincare, the father of modern mathematical dynamical systems, much effort has been exerted to achieve a qualitative understanding of the physical world via a qualitative understanding of the functions we use to model the physical world. In this thesis, we construct a numerical framework suitable for a qualitative, statistical study of dynamical systems using the space of artificial neural networks. We analyze the dynamics along intervals in parameter space, separating the set of neural networks into roughly four regions: the fixed point to the first bifurcation; the route to chaos; the chaotic region; and a transition region between chaos and finite-state neural networks. The study is primarily with respect to high-dimensional dynamical systems. We make the following general conclusions as the dimension of the dynamical system is increased: the probability of the first bifurcation being of type Neimark-Sacker is greater than ninety-percent; the most probable route to chaos is via a cascade of bifurcations of high-period periodic orbits, quasi-periodic orbits, and 2-tori; there exists an interval of parameter space such that hyperbolicity is violated on a countable, Lebesgue measure 0, "increasingly dense" subset; chaos is much more likely to persist with respect to parameter perturbation in the chaotic region of parameter space as the dimension is increased; moreover, as the number of positive Lyapunov exponents is increased, the likelihood that any significant portion of these positive exponents can be perturbed away decreases with increasing dimension. The maximum Kaplan-Yorke dimension and the maximum number of positive Lyapunov exponents increases linearly with dimension. The probability of a dynamical system being chaotic increases exponentially with dimension. The results with respect to the first bifurcation and the route to chaos comment on previous results of Newhouse, Ruelle, Takens, Broer, Chenciner, and Iooss. Moreover, results regarding the high-dimensional
DEFF Research Database (Denmark)
Guo, Xiaoqiang; Cavalcanti, Marcelo C.; Farias, Alexandre M.
2013-01-01
Modulation strategy is one of the most important issues for three-level neutral-point-clamped inverters in three-phase transformerless photovoltaic systems. A challenge for modulation is how to keep the common-mode voltages constant to reduce the leakage currents. A single-carrier modulation...... strategy is proposed. It has a very simple structure, and the common-mode voltages can be kept constant with no need of complex space-vector modulation or multicarrier pulsewidth modulation. Experimental results verify the theoretical analysis and the effectiveness of the presented method....
International Nuclear Information System (INIS)
Chen, J.-D.
2007-01-01
In this paper, the robust control problem of output dynamic observer-based control for a class of uncertain neutral systems with discrete and distributed time delays is considered. Linear matrix inequality (LMI) optimization approach is used to design the new output dynamic observer-based controls. Three classes of observer-based controls are proposed and the maximal perturbed bound is given. Based on the results of this paper, the constraint of matrix equality is not necessary for designing the observer-based controls. Finally, a numerical example is given to illustrate the usefulness of the proposed method
Two dimensional electron systems for solid state quantum computation
Mondal, Sumit
Two dimensional electron systems based on GaAs/AlGaAs heterostructures are extremely useful in various scientific investigations of recent times including the search for quantum computational schemes. Although significant strides have been made over the past few years to realize solid state qubits on GaAs/AlGaAs 2DEGs, there are numerous factors limiting the progress. We attempt to identify factors that have material and design-specific origin and develop ways to overcome them. The thesis is divided in two broad segments. In the first segment we describe the realization of a new field-effect induced two dimensional electron system on GaAs/AlGaAs heterostructure where the novel device-design is expected to suppress the level of charge noise present in the device. Modulation-doped GaAs/AlGaAs heterostructures are utilized extensively in the study of quantum transport in nanostructures, but charge fluctuations associated with remote ionized dopants often produce deleterious effects. Electric field-induced carrier systems offer an attractive alternative if certain challenges can be overcome. We demonstrate a field-effect transistor in which the active channel is locally devoid of modulation-doping, but silicon dopant atoms are retained in the ohmic contact region to facilitate low-resistance contacts. A high quality two-dimensional electron gas is induced by a field-effect that is tunable over a density range of 6.5x10 10cm-2 to 2.6x1011cm-2 . Device design, fabrication, and low temperature (T=0.3K) characterization results are discussed. The demonstrated device-design overcomes several existing limitations in the fabrication of field-induced 2DEGs and might find utility in hosting nanostructures required for making spin qubits. The second broad segment describes our effort to correlate transport parameters measured at T=0.3K to the strength of the fractional quantum Hall state observed at nu=5/2 in the second Landau level of high-mobility GaAs/AlGaAs two dimensional
Structural analysis of the Passive Magnetic Shield for the ITER Heating Neutral Beam Injector system
Energy Technology Data Exchange (ETDEWEB)
Cabrera, Santiago, E-mail: santiago.cabrera@ciemat.es [CIEMAT Laboratorio Nacional de Fusión, Avda. Complutense 40, 28040 Madrid (Spain); Rincón, Esther; Ahedo, Begoña; Alonso, Javier; Barrera, Germán; Ramos, Francisco; Ríos, Luis [CIEMAT Laboratorio Nacional de Fusión, Avda. Complutense 40, 28040 Madrid (Spain); El-Ouazzani, Anass; García, Pablo [ITER Organization, Route de Vinon-sur-Verdon – CS 90 046, 13067 St Paul Lez Durance Cedex (France); Agarici, Gilbert [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3 – 07/08, 08019 Barcelona (Spain)
2015-10-15
The ITER Passive Magnetic Shield (PMS) main function is to protect the Neutral Beam Injector (NBI) from the external magnetic field coming from the tokamak, and to shield the NB cell from the radiation coming from all activated components. The shielding from the external magnetic field is performed in association with the Active Compensation Cooled Correction Coils (ACCC). The Bushing and Transmission Line (TL) PMS also provides structural support for HV bushing, allowing its maintenance and providing air sealing function between NBI cell and High Voltage deck room. The paper summarizes the structural analyses performed in order to evaluate the mechanical behaviour of the HNB PMS under operation combined with seismic event. The RCC-MR Code is used to validate the design, assuming creep is negligible, since the structure is expected to be at room temperature. P-type damage is assessed.
Neural Network-Based Passive Filtering for Delayed Neutral-Type Semi-Markovian Jump Systems.
Shi, Peng; Li, Fanbiao; Wu, Ligang; Lim, Cheng-Chew
2017-09-01
This paper investigates the problem of exponential passive filtering for a class of stochastic neutral-type neural networks with both semi-Markovian jump parameters and mixed time delays. Our aim is to estimate the states by designing a Luenberger-type observer, such that the filter error dynamics are mean-square exponentially stable with an expected decay rate and an attenuation level. Sufficient conditions for the existence of passive filters are obtained, and a convex optimization algorithm for the filter design is given. In addition, a cone complementarity linearization procedure is employed to cast the nonconvex feasibility problem into a sequential minimization problem, which can be readily solved by the existing optimization techniques. Numerical examples are given to demonstrate the effectiveness of the proposed techniques.
Calibration of the ORNL two-dimensional Thomson scattering system
International Nuclear Information System (INIS)
Thomas, C.E. Jr.; Lazarus, E.A.; Kindsfather, R.R.; Murakami, M.; Stewart, K.A.
1985-10-01
A unified presentation of the calibrations needed for accurate calculation of electron temperature and density from Thomson scattering data for the Oak Ridge National Laboratory two-dimensional Thomson scattering system (SCATPAK II) is made. Techniques are described for measuring the range of wavelengths to which each channel is responsive. A statistical method for calibrating the gain of each channel in the system is given, and methods of checking for internal consistency and accuracy are presented. The relationship between the constants describing the relative light collection efficiency of each channel and plasma light-scattering theory is developed, methods for measuring the channel efficiencies and evaluating their accuracy are described, and the effect on these constants of bending fiber optics is discussed. The use of Rayleigh or Raman scattering for absolute efficiency (density) calibration, stray light measurement, and system efficiency evaluation is discussed; the relative merits of Rayleigh vs Raman scattering are presented; and the relationship among the Rayleigh/Raman calibrations, relative channel efficiency constants, and absolute efficiencies is developed
Unraveling surface enabled magnetic phenomena in low dimensional systems
Baljozovic, Milos; Girovsky, Jan; Nowakowski, Jan; Ali, Md Ehesan; Rossmann, Harald; Nijs, Thomas; Aeby, Elise; Nowakowska, Sylwia; Siewert, Dorota; Srivastava, Gitika; WäCkerlin, Christian; Dreiser, Jan; Decurtins, Silvio; Liu, Shi-Xia; Oppeneer, Peter M.; Jung, Thomas A.; Ballav, Nirmalya
Molecular spin systems with controllable interactions are of both fundamental and applied importance. These systems help us to better understand the fundamental origins of the interactions involved in low dimensional magnetic systems and to put them in the framework of existing models towards their further development. Following our first observation of exchange induced magnetic ordering in paramagnetic porphyrins adsorbed on ferromagnetic Co surface we showed that magnetic properties of such molecules can be controllably altered upon exposure to chemical and physical stimuli. In our most recent work it was shown that a synthetically programmed co-assembly of Fe and Mn phthalocyanines can also be realized on diamagnetic Au(111) surfaces where it induces long-range 2D ferrimagnetic order, at first glance in conflict with the Mermin-Wagner theory. Here we provide evidence for the first direct observation of such ordering from STM/STS and XMCD data and from DFT +U calculations demonstrating key role of the Au(111) surface states in mediating AFM RKKY coupling of the Kondo underscreened magnetic moments.
Performance Estimation for Two-Dimensional Brownian Rotary Ratchet Systems
Tutu, Hiroki; Horita, Takehiko; Ouchi, Katsuya
2015-04-01
Within the context of the Brownian ratchet model, a molecular rotary system that can perform unidirectional rotations induced by linearly polarized ac fields and produce positive work under loads was studied. The model is based on the Langevin equation for a particle in a two-dimensional (2D) three-tooth ratchet potential of threefold symmetry. The performance of the system is characterized by the coercive torque, i.e., the strength of the load competing with the torque induced by the ac driving field, and the energy efficiency in force conversion from the driving field to the torque. We propose a master equation for coarse-grained states, which takes into account the boundary motion between states, and develop a kinetic description to estimate the mean angular momentum (MAM) and powers relevant to the energy balance equation. The framework of analysis incorporates several 2D characteristics and is applicable to a wide class of models of smooth 2D ratchet potential. We confirm that the obtained expressions for MAM, power, and efficiency of the model can enable us to predict qualitative behaviors. We also discuss the usefulness of the torque/power relationship for experimental analyses, and propose a characteristic for 2D ratchet systems.
Three-Dimensional Reconstruction Optical System Using Shadows Triangulation
Barba, J. Leiner; Vargas, Q. Lorena; Torres, M. Cesar; Mattos, V. Lorenzo
2008-04-01
In this work is developed a three-dimensional reconstruction system using the Shades3D tool of the Matlab® Programming Language and materials of low cost, such as webcam camera, a stick, a weak structured lighting system composed by a desk lamp, and observation plane in which the object is located. The reconstruction is obtained through a triangulation process that is executed after acquiring a sequence of images of the scene with a shadow projected on the object; additionally an image filtering process is done for obtaining only the part of the scene that will be reconstructed. Previously, it is necessary to develop a calibration process for determining the internal camera geometric and optical characteristics (intrinsic parameters), and the 3D position and orientation of the camera frame relative to a certain world coordinate system (extrinsic parameters). The lamp and the stick are used to produce a shadow which scans the object; in this technique, it is not necessary to know the position of the light source, instead the triangulation is obtained using shadow plane produced by intersection between the stick and the illumination pattern. The webcam camera captures all images with the shadow scanning the object, and Shades3D tool processes all information taking into account captured images and calibration parameters. Likewise, this technique is evaluated in the reconstruction of parts of the human body and its application in the detection of external abnormalities and elaboration of prosthesis or implant.
A Three-Dimensional Wireless Indoor Localization System
Directory of Open Access Journals (Sweden)
Ping Yi
2014-01-01
Full Text Available Indoor localization, an emerging technology in location based service (LBS, is now playing a more and more important role both in commercial and in civilian industry. Global position system (GPS is the most popular solution in outdoor localization field, and the accuracy is around 10 meter error in positioning. However, with complex obstacles in buildings, problems rise in the “last mile” of localization field, which encourage a momentum of indoor localization. The traditional indoor localization system is either range-based or fingerprinting-based, which requires a lot of time and efforts to do the predeployment. In this paper, we present a 3-dimensional on-demand indoor localization system (3D-ODIL, which can be fingerprint-free and deployed rapidly in a multistorey building. The 3D-ODIL consists of two phases, vertical localization and horizontal localization. On vertical direction, we propose multistorey differential (MSD algorithm and implement it to fulfill the vertical localization, which can greatly reduce the number of anchors deployed. We use enhanced field division (EFD algorithm to conduct the horizontal localization. EFD algorithm is a range-free algorithm, the main idea of which is to dynamically divide the field within different signature area and position the target. The accuracy and performance have been validated through our extensive analysis and systematic experiments.
Accurate correlation energies in one-dimensional systems from small system-adapted basis functions
Baker, Thomas E.; Burke, Kieron; White, Steven R.
2018-02-01
We propose a general method for constructing system-dependent basis functions for correlated quantum calculations. Our construction combines features from several traditional approaches: plane waves, localized basis functions, and wavelets. In a one-dimensional mimic of Coulomb systems, it requires only 2-3 basis functions per electron to achieve high accuracy, and reproduces the natural orbitals. We illustrate its effectiveness for molecular energy curves and chains of many one-dimensional atoms. We discuss the promise and challenges for realistic quantum chemical calculations.
Tomograms for open quantum systems: In(finite) dimensional optical and spin systems
International Nuclear Information System (INIS)
Thapliyal, Kishore; Banerjee, Subhashish; Pathak, Anirban
2016-01-01
Tomograms are obtained as probability distributions and are used to reconstruct a quantum state from experimentally measured values. We study the evolution of tomograms for different quantum systems, both finite and infinite dimensional. In realistic experimental conditions, quantum states are exposed to the ambient environment and hence subject to effects like decoherence and dissipation, which are dealt with here, consistently, using the formalism of open quantum systems. This is extremely relevant from the perspective of experimental implementation and issues related to state reconstruction in quantum computation and communication. These considerations are also expected to affect the quasiprobability distribution obtained from experimentally generated tomograms and nonclassicality observed from them. -- Highlights: •Tomograms are constructed for open quantum systems. •Finite and infinite dimensional quantum systems are studied. •Finite dimensional systems (phase states, single & two qubit spin states) are studied. •A dissipative harmonic oscillator is considered as an infinite dimensional system. •Both pure dephasing as well as dissipation effects are studied.
Tomograms for open quantum systems: In(finite) dimensional optical and spin systems
Energy Technology Data Exchange (ETDEWEB)
Thapliyal, Kishore, E-mail: tkishore36@yahoo.com [Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India); Banerjee, Subhashish, E-mail: subhashish@iitj.ac.in [Indian Institute of Technology Jodhpur, Jodhpur 342011 (India); Pathak, Anirban, E-mail: anirban.pathak@gmail.com [Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India)
2016-03-15
Tomograms are obtained as probability distributions and are used to reconstruct a quantum state from experimentally measured values. We study the evolution of tomograms for different quantum systems, both finite and infinite dimensional. In realistic experimental conditions, quantum states are exposed to the ambient environment and hence subject to effects like decoherence and dissipation, which are dealt with here, consistently, using the formalism of open quantum systems. This is extremely relevant from the perspective of experimental implementation and issues related to state reconstruction in quantum computation and communication. These considerations are also expected to affect the quasiprobability distribution obtained from experimentally generated tomograms and nonclassicality observed from them. -- Highlights: •Tomograms are constructed for open quantum systems. •Finite and infinite dimensional quantum systems are studied. •Finite dimensional systems (phase states, single & two qubit spin states) are studied. •A dissipative harmonic oscillator is considered as an infinite dimensional system. •Both pure dephasing as well as dissipation effects are studied.
Institute of Scientific and Technical Information of China (English)
YANGYong－Hong; WANGYong－Gang; 等
2002-01-01
Two kinds of spin-dependent scattering effects (magnetic-impurity and spin-orbit scatterings) are investigated theoretically in a quasi-tow-dimensional (quasi-2D) disordered electron system.By making use of the diagrammatic techniques in perturbation theory,we have calculated the dc conductivity and magnetoresistance due to weak-localization effects,the analytical expressions of them are obtained as functions of the interlayer hopping energy and the characteristic times:elastic,inelastic,magnetic and spin-orbit scattering times.The relevant dimensional crossover behavior from 3D to 2D with decreasing the interlayer coupling is discussed,and the condition for the crossover is shown to be dependent on the aforementioned scattering times.At low temperature there exists a spin-dependent-scattering-induced dimensional crossover in this system.
International Nuclear Information System (INIS)
Pomaro, Nicola; Boldrin, Marco; Lazzaro, Gabriele
2015-01-01
Highlights: • We designed a high performance earthing system for the ITER Neutral Beam Test Facility. • The system is based on the Mesh Common Bonded Network topology. • Careful bonding of all metallic structures allowed to obtain a well meshed system. • Special care was dedicated to improve EMC performance of critical areas like control rooms. • The facility experimental results will be representative also of the ITER situation. - Abstract: PRIMA is a large experimental facility under realization in Padova, aimed at developing and testing the Neutral Beam Injectors for ITER. The operation of these devices involves high RF power and voltage up to 1 MV. Frequent and high voltage electrical breakdowns inside the beam sources occur regularly. The presence of a distributed carefully optimized earthing system is of paramount importance to achieve a satisfying disturbances immunity for equipment and diagnostics. The paper describes the design and the realization of the earthing system of the PRIMA facility, which is based on the MESH-Common Bonding Network (MESH-CBN) topology, as recommended by IEC and IEEE standards for installations with high levels of Electromagnetic Interferences (EMI). The principles of the MESH-CBN approach were adapted to the PRIMA layout, which is composed by several buildings, that are independent for seismic and architectural reasons, but are linked by many electrical conduits and hydraulic pipelines. The availability of huge foundations, with a large number of poles and pillars, was taken into account; building parts dedicated to host control rooms and sensitive equipment were treated with particular care. Moreover, the lightning protection system was integrated and harmonized with the earthing system.
Energy Technology Data Exchange (ETDEWEB)
Pomaro, Nicola, E-mail: nicola.pomaro@igi.cnr.it; Boldrin, Marco; Lazzaro, Gabriele
2015-10-15
Highlights: • We designed a high performance earthing system for the ITER Neutral Beam Test Facility. • The system is based on the Mesh Common Bonded Network topology. • Careful bonding of all metallic structures allowed to obtain a well meshed system. • Special care was dedicated to improve EMC performance of critical areas like control rooms. • The facility experimental results will be representative also of the ITER situation. - Abstract: PRIMA is a large experimental facility under realization in Padova, aimed at developing and testing the Neutral Beam Injectors for ITER. The operation of these devices involves high RF power and voltage up to 1 MV. Frequent and high voltage electrical breakdowns inside the beam sources occur regularly. The presence of a distributed carefully optimized earthing system is of paramount importance to achieve a satisfying disturbances immunity for equipment and diagnostics. The paper describes the design and the realization of the earthing system of the PRIMA facility, which is based on the MESH-Common Bonding Network (MESH-CBN) topology, as recommended by IEC and IEEE standards for installations with high levels of Electromagnetic Interferences (EMI). The principles of the MESH-CBN approach were adapted to the PRIMA layout, which is composed by several buildings, that are independent for seismic and architectural reasons, but are linked by many electrical conduits and hydraulic pipelines. The availability of huge foundations, with a large number of poles and pillars, was taken into account; building parts dedicated to host control rooms and sensitive equipment were treated with particular care. Moreover, the lightning protection system was integrated and harmonized with the earthing system.
Classical and quantum phases of low-dimensional dipolar systems
Energy Technology Data Exchange (ETDEWEB)
Cartarius, Florian
2016-09-22
In this thesis we present a detailed study of the phase diagram of ultracold bosonic atoms confined along a tight atomic wave guide, along which they experience an optical lattice potential. In this quasi-one dimensional model we analyse the interplay between interactions and quantum fluctuations in (i) determining the non-equilibrium steady state after a quench and (ii) giving rise to novel equilibrium phases, when the interactions combine the s-wave contact interaction and the anisotropic long range dipole-dipole interactions. In detail, in the first part of the thesis we study the depinning of a gas of impenetrable bosons following the sudden switch of of the optical lattice. By means of a Bose-Fermi mapping we infer the exact quantum dynamical evolution and show that in the thermodynamic limit the system is in a non-equilibrium steady state without quasi-long range order. In the second part of the thesis, we study the effect of quantum fluctuations on the linear-zigzag instability in the ground state of ultracold dipolar bosons, as a function of the strength of the transverse confinement. We first analyse the linear-zigzag instability in the classical regime, and then use our results to develop a multi-mode Bose-Hubbard model for the system. We then develop several numerical methods, to determine the ground state.
Nie, Jianhui; Wu, Xiaohong; Ma, Jian; Cao, Shouchun; Huang, Weijin; Liu, Qiang; Li, Xuguang; Li, Yuhua; Wang, Youchun
2017-01-01
Pseudoviruses are useful virological tools because of their safety and versatility; however the low titer of these viruses substantially limits their wider applications. We developed a highly efficient pseudovirus production system capable of yielding 100 times more rabies pseudovirus than the traditional method. Employing the high-titer pseudoviruses, we have developed robust in vitro and in vivo neutralization assays for the evaluation of rabies vaccine, which traditionally relies on live-virus based assays. Compared with current rapid fluorescent focus inhibition test (RFFIT), our in vitro pseudovirus-based neutralization assay (PBNA) is much less labor-intensive while demonstrating better reproducibility. Moreover, the in vivo PBNA assay was also found to be superior to the live virus based assay. Following intravenous administration, the pseudovirus effectively infected the mice, with dynamic viral distributions being sequentially observed in spleen, liver and brain. Furthermore, data from in vivo PBNA showed great agreement with those generated from the live virus model but with the experimental time significantly reduced from 2 weeks to 3 days. Taken together, the effective pseudovirus production system facilitated the development of novel PBNA assays which could replace live virus-based traditional assays due to its safety, rapidity, reproducibility and high throughput capacity. PMID:28218278
Observation of Matter-Antimatter Asymmetry in the Neutral B Meson System
Energy Technology Data Exchange (ETDEWEB)
Rahatlou, S
2003-12-19
In this dissertation, a measurement of CP-violating effects in decays of neutral B meson is presented. The data sample for this measurement consists of about 88 million {Upsilon}(4S) {yields} B{bar B} decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider, located at the Stanford Linear Accelerator Center. One neutral B meson is fully reconstructed in the CP eigenstates J/{psi} K{sub S}{sup 0}, {psi}(2S)K{sub S}{sup 0}, {chi}{sub c1}K{sub S}{sup 0}, and {eta}{sub c}K{sub S}{sup 0}, or in the flavor eigenstates D(*){sup -} {pi}{sup +}/{rho}{sup +}/a{sub 1}{sup +} and J/{psi} K*{sup 0} (K*{sup 0} {yields} K{sup +}{pi}{sup -}). The other B meson is determined to be either a B{sup 0} or a {bar B}{sup 0}, at the time of its decay, from the properties of its decay products. The proper time {Delta}t elapsed between the decay of the two mesons is determined by reconstructing their decay vertices, and by measuring the distance between them. The CP asymmetry amplitude sin2{beta} is determined by the distributions of {Delta}t in events with a reconstructed B meson in CP eigenstates. The detector resolution and the b-flavor-tagging parameters are constrained by the {Delta}t distributions of events with a fully reconstructed flavor eigenstate. From a simultaneous maximum-likelihood fit to the {Delta}t distributions of all selected events in CP and flavor eigenstates, the value of sin2{beta} is measured to be 0.755 {+-} 0.074(stat) {+-} 0.030(syst). This value is in agreement with the Standard Model prediction, and represents a successful test of the Kobayashi-Maskawa mechanism of CP violation.
International Nuclear Information System (INIS)
Staten, H.S.
1980-08-01
The national plan is presented for developing advanced injection systems for use on upgrades of existing experiments, and use on future facilities such as ETF, to be built in the late 1980's or early 90's where power production from magnetic fusion will move closer to a reality. Not only must higher power and longer pulse length systems be developed , but they must operate reliably; they must be a tool for the experimenter, not the experiment itself. Neutral beam systems handle large amounts of energy and as such, they often are as complicated as the plasma physics experiment itself. This presents a significant challenge to the neutral beam developer
International Nuclear Information System (INIS)
Anon.
1979-01-01
The structure of the beam injection program for the Doublet-3 device is discussed. The design considerations for the beam line and design parameters for the Doublet-3 ion souce are given. Major components of the neutral beam injector system are discussed in detail. These include the neutralizer, magnetic shielding, reflecting magnets, vacuum system, calorimeter and beam dumps, and drift duct. The planned location of the two-injector system for Doublet-3 is illustrated and site preparation is considered. The status of beamline units 1 and 2 and the future program schedule are discussed
Becus, Georges A.; Chan, Alistair K.
1993-01-01
Three neural network processing approaches in a direct numerical optimization model reduction scheme are proposed and investigated. Large structural systems, such as large space structures, offer new challenges to both structural dynamicists and control engineers. One such challenge is that of dimensionality. Indeed these distributed parameter systems can be modeled either by infinite dimensional mathematical models (typically partial differential equations) or by high dimensional discrete models (typically finite element models) often exhibiting thousands of vibrational modes usually closely spaced and with little, if any, damping. Clearly, some form of model reduction is in order, especially for the control engineer who can actively control but a few of the modes using system identification based on a limited number of sensors. Inasmuch as the amount of 'control spillover' (in which the control inputs excite the neglected dynamics) and/or 'observation spillover' (where neglected dynamics affect system identification) is to a large extent determined by the choice of particular reduced model (RM), the way in which this model reduction is carried out is often critical.
Method and system for manipulating a digital representation of a three-dimensional object
DEFF Research Database (Denmark)
2010-01-01
A method of manipulating a three-dimensional virtual building block model by means of two-dimensional cursor movements, the virtual building block model including a plurality of virtual building blocks each including a number of connection elements for connecting the virtual building block...... with another virtual building block according to a set of connection rules, the method comprising positioning by means of cursor movements in a computer display area representing a two-dimensional projection of said model, a two-dimensional projection of a first virtual building block to be connected...... to the structure, resulting in a two-dimensional position; determining, from the two-dimensional position, a number of three-dimensional candidate positions of the first virtual building block in the three-dimensional coordinate system; selecting one of said candidate positions based on the connection rules...
Monte-Carlo calculation of perpendicular neutral-beam injection in helical systems
International Nuclear Information System (INIS)
Hanatani, K.; Wakatani, M.; Uo, K.
1981-01-01
The effect of a helical field ripple on the slowing-down process of the fast ions created by neutral injection is investigated numerically. For this purpose, the guiding-centre orbits are followed in a model magnetic field without plasma current, on the assumption that the slowing-down process is to be classical. Optimum injection angles in two types of helical magnetic traps are compared. One is the Heliotron-E configuration with a large rotational transform and deep helical ripple; the other one is the conventional stellarator field with a small rotational transform and shallow helical ripple. In contrast to the stellarator, the heating efficiency as calculated for Heliotron-E does not decrease monotonically when the injection angle is perpendicular to the toroidal direction; a heating efficiency of above 70% was obtained for perpendicular injection into a high-density plasma with negligible charge-exchange loss. The difference in heating efficiency versus injection angle between heliotron and conventional stellarator fields is explained by a difference in drift motion of the helically trapped fast ions. (author)
Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System
Energy Technology Data Exchange (ETDEWEB)
Worcester, Elizabeth Turner [Univ. of Chicago, IL (United States)
2007-12-01
The authors present precision measurements of the direct CP violation parameter, Re(ϵ'/ϵ), the kaon parameters, Δm and τ_{S}, and the CPT tests, Φ_{±} and ΔΦ, in neutral kaon decays. These results are based on the full dataset collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This dataset contains ~ 15 million K → π^{0}π^{0} decays and ~ 69 million K → π^{+}π^{-} decays. They describe significant improvements to the precision of these measurements relative to previous KTeV analyses. They find Re(ϵ'/ϵ = [19.2 ± 1.1(stat) ± 1.8(syst)] x 10^{-4}, Δm = (5265 ± 10) x 10^{6} hs^{-1}, and τ_{S} = (89.62 ± 0.05) x 10^{-12} s. They measure Φ_{±} = (44.09 ± 1.00)° and ΔΦ = (0.29 ± 0.31)°; these results are consistent with CPT symmetry.
International Nuclear Information System (INIS)
Fiorucci, Donatella
2015-01-01
This work is part of a larger project called SIPHORE (Single gap Photo-neutralizer energy Recovery injector), which aims to enhance the overall efficiency of one of the mechanisms through which the plasma is heated, in a nuclear fusion reactor, i.e. the Neutral Beam Injection (NBI) system. An important component of a NBI system is the neutralizer of high energetic ion beams. SIPHORE proposes to substitute the gas cell neutralizer, used in the current NBI systems, with a photo-neutralizer exploiting the photo-detachment process within Fabry Perot cavities. This mechanism should allow a relevant NBI global efficiency of η≥ 60%, significantly higher than the one currently possible (η≤25% for ITER). The present work concerns the feasibility study of an optical cavity with suitable properties for applications in NBI systems. Within this context, the issue of the determination of an appropriated optical cavity design has been firstly considered and the theoretical and experimental analysis of a particular optical resonator has been carried on. The problems associated with the high levels of intracavity optical power (∼3 MW) required for an adequate photo-neutralization rate have then been faced. In this respect, we addressed both the problem of the thermal effects on the cavity mirrors due to their absorption of intra-cavity optical power (∼1 W) and the one associated to the necessity of a high powerful input laser beam (∼1 kW) to feed the optical resonator. (author)
A practical three-dimensional dosimetry system for radiation therapy
International Nuclear Information System (INIS)
Guo Pengyi; Adamovics, John; Oldham, Mark
2006-01-01
There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE trade mark sign ) and a commercial optical computed tomography (CT) scanning system (OCTOPUS trade mark sign ). PRESAGE trade mark sign is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need for an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE trade mark sign /OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of ≤1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R 2 value of 0.9979 and a standard error of estimation of ∼1%) relative to independent measurement. The overall performance of the PRESAGE trade mark sign /OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC[reg] EBT film and the calculated dose from a commissioned planning system. The 'measured' dose distribution in a cylindrical PRESAGE trade mark sign dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE trade mark sign , EBT and calculated dose distributions, showed full agreement in
Phillips, Robert; Lanza di Scalea, Francesco; Nucera, Claudio; Fateh, Mahmood; Choros, John
2014-03-01
In both high speed and freight rail systems, the modern construction method is Continuous Welded Rail (CWR). The purpose of the CWR method is to eliminate joints in order to reduce the maintenance costs for both the rails and the rolling stock. However the elimination of the joints increases the risk of rail breakage in cold weather and buckling in hot weather. In order to predict the temperature at which the rail will break or buckle, it is critical to have knowledge of the temperature at which the rail is stress free, namely, the Rail Neutral Temperature (Rail-NT).The University of California at San Diego has developed an innovative technique based on non-linear ultrasonic guided waves, under FRA research and development grants for the non-destructive measurement of the neutral temperature of railroad tracks. Through the licensing of this technology from the UCSD and under the sponsorship of the FRA Office of Research and Development, a field deployable prototype system has been developed and recently field tested at cooperating railroad properties. Three prototype systems have been deployed to the Union Pacific (UP), Burlington Northern Santa Fe (BNSF), and AMTRAK railroads for field testing and related data acquisition for a comprehensive evaluation of the system, with respect to both performance and economy of operation. The results from these tests have been very encouraging. Based on the lessons learned from these field tests and the feedback from the railroads, it is planned develop a compact 2nd generation Rail-NT system to foster deployment and furtherance of FRA R&D grant purpose of potential contribution to the agency mission of US railroad safety. In this paper, the results of the field tests with the railroads in summer of 2013 are reported.
Volumetric three-dimensional display system with rasterization hardware
Favalora, Gregg E.; Dorval, Rick K.; Hall, Deirdre M.; Giovinco, Michael; Napoli, Joshua
2001-06-01
An 8-color multiplanar volumetric display is being developed by Actuality Systems, Inc. It will be capable of utilizing an image volume greater than 90 million voxels, which we believe is the greatest utilizable voxel set of any volumetric display constructed to date. The display is designed to be used for molecular visualization, mechanical CAD, e-commerce, entertainment, and medical imaging. As such, it contains a new graphics processing architecture, novel high-performance line- drawing algorithms, and an API similar to a current standard. Three-dimensional imagery is created by projecting a series of 2-D bitmaps ('image slices') onto a diffuse screen that rotates at 600 rpm. Persistence of vision fuses the slices into a volume-filling 3-D image. A modified three-panel Texas Instruments projector provides slices at approximately 4 kHz, resulting in 8-color 3-D imagery comprised of roughly 200 radially-disposed slices which are updated at 20 Hz. Each slice has a resolution of 768 by 768 pixels, subtending 10 inches. An unusual off-axis projection scheme incorporating tilted rotating optics is used to maintain good focus across the projection screen. The display electronics includes a custom rasterization architecture which converts the user's 3- D geometry data into image slices, as well as 6 Gbits of DDR SDRAM graphics memory.
Unexpected magnetism in low dimensional systems: the role of symmetry
International Nuclear Information System (INIS)
Munoz, MC; Chico, L; Lopez-Sancho, MP; Beltran, JI; Gallego, S; Cerda, J
2006-01-01
The symmetry underlying the geometric structure of materials determines most of their physical properties. In low dimensional systems the role of symmetry is enhanced and can give rise to new phenomena. Here, we report on unexpected magnetism in carbon nanotubes and O-rich surfaces of ionic oxides, to show how its existence is closely related to the symmetry conditions. First, based on tight-binding models, we demonstrate that chiral carbon nanotubes present spin splitting at the Fermi level in the absence of a magneticfield, whereas achiral tubes preserve spin degeneracy. These remarkably different behaviors of chiral and non-chiral nanotubes are due to the intrinsic symmetry dependence of the spin-orbit interaction. Second, the occurrence of spin-polarization at ZrO 2 , Al 2 O 3 and MgO surfaces is proved by means of abinitio calculations within the density functional theory. Large spin moments develop at O-ended polar terminations, transforming the non-magnetic insulator into a half-metal. The magnetic moments mainly reside in the surface oxygen atoms, and their origin is related to the existence of 2p holes of well-defined spin polarization at the valence band of the ionic oxide. The direct relation between magnetization and local loss of donor charge shows that at the origin of these phenomena is the reduced surface symmetry
Conformal algebras of two-dimensional disordered systems
International Nuclear Information System (INIS)
Gurarie, Victor; Ludwig, Andreas W.W.
2002-01-01
We discuss the structure of two-dimensional conformal field theories at a central charge c=0 describing critical disordered systems, polymers and percolation. We construct a novel extension of the c=0 Virasoro algebra, characterized by a number b measuring the effective number of massless degrees of freedom, and by a logarithmic partner of the stress tensor. It is argued to be present at a generic random critical point, lacking super Kac-Moody, or other higher symmetries, and is a tool to describe and classify such theories. Interestingly, this algebra is not only consistent with, but indeed naturally accommodates in general an underlying global supersymmetry. Polymers and percolation realize this algebra. Unexpectedly, we find that the c=0 Kac table of the degenerate fields contains two distinct theories with b=5/6 and b=-5/8 which we conjecture to correspond to percolation and polymers, respectively. A given Kac-table field can be degenerate only in one of them. Remarkably, we also find this algebra, and thereby an ensuing hidden supersymmetry, realized at general replica-averaged critical points, for which we derive an explicit formula for b. (author). Letter-to-the-editor
International Nuclear Information System (INIS)
Noda, Shunichi; Nagae, Hiroshi; Yano, Hidenobu; Masuda, Mitsuharu; Akazaki, Masanori
1986-01-01
The injection of fast neutral beams into plasmas is thought to be the most promising way for the fusion plasma heating. Fast neutral beams are obtained by injecting fast ions into a neutralizer cell, in which ions are neutralized through charge exchange collisions with the ambient gas. However, the neutralization efficiency in the neutralizer cell is so low that the net power may not be extracted from a fusion reactor unless the energy of the ions being not neutralized in the cell is recovered. The present paper describes some problems associated with the electrostatic direct energy recovery of fast ion beams for this purpose. The titanium and molybdenum were tested as the direct converter electrode materials, and it was found that the conversion efficiency and the conditioning process of the converter electrode depended strongly on the electrode material. The effect of secondary electrons emitted from the electron repeller on the conversion efficiency was also made clear in the present experiments. (author)
A 4π scintillation counter-optical spark chamber system for neutral particles
International Nuclear Information System (INIS)
Demarzo, C.; Distante, A.; Guerriero, L.; Niccolini, C.; Posa, F.; Walder, F.; Chen, G.T.Y.; Fletcher, C.R.; Lanou, R.E. Jr.; Thornton, R.K.; Barton, D.S.; Lyons, T.; Marx, M.; Rosenson, L.; Thern, R.
1975-01-01
The authors describe a scintillation counter-optical spark chamber system developed for the detection of high energy gamma rays and neutrons. They describe the system components and their use in two completed experiments. (Auth.)
Two-dimensional readout system for radiation detector
International Nuclear Information System (INIS)
Lee, L.Y.
1975-01-01
A two dimensional readout system has been provided for reading out locations of scintillations produced in a scintillation type radiation detector array wherein strips of scintillator material are arranged in a parallel planar array. Two sets of light guides are placed perpendicular to the scintillator strips, one on the top and one on the bottom to extend in alignment across the strips. Both the top and bottom guides are composed of a number of 90 0 triangular prisms with the lateral side forming the hypotenuse equal to twice the width of a scintillator strip. The prism system reflects light from a scintillation along one of the strips back and forth through adjacent strips to light pipes coupled to the outermost strips of the detector array which transmit light pulses to appropriate detectors to determine the scintillation along one axis. Other light pipes are connected to the end portions of the strips to transmit light from the individual strips to appropriate light detectors to indicate the particular strip activated, thereby determining the position of a scintillation along the other axis. The number of light guide pairs may be equal the number of the scintillation strips when equal spatial resolution for each of the two coordinates is desired. When the scintillator array detects an event which produces a scintillation along one of the strips, the emitted light travels along four different paths, two of which are along the strip, and two of which are through the light guide pair perpendicular to the strips until all four beams reach the outer edges of the array where they may be transmitted to light detectors by means of light pipes connected therebetween according to a binary code for direct digital readout. (U.S.)
International Nuclear Information System (INIS)
Brockmann, H.
1992-01-01
Using the discrete ordinates method for the treatment of neutral particle transport through voids serious flux distortions may occur due to the restricted streaming of particles along discrete directions. For mitigating this type of ray effect the method of view factors is proposed which has been developed in the theory of thermal radiation for describing the radiant exchange among surfaces. In order to apply this method to transport theory generalized view factors are defined which regard the angular dependence of the radiation leaving the surfaces. The generalized view factors are calculated analytically for r-z cylinder geometries and by applying the view factor algebra. The method was realized in the discrete ordinates transport code DOT 4.2 and applied to an r-z analogue of the S I S (Square-In-Square) sample problem. The results of the proposed method are compared with those calculated by the common discrete ordinates method and the Monte Carlo method
Study of three-dimensional image display by systemic CT
International Nuclear Information System (INIS)
Fujioka, Tadao; Ebihara, Yoshiyuki; Unei, Hiroshi; Hayashi, Masao; Shinohe, Tooru; Wada, Yuji; Sakai, Takatsugu; Kashima, Kenji; Fujita, Yoshihiro
1989-01-01
A head phantom for CT was scanned at 2 mm intervals from the cervix to the vertex in an attempt to obtain a three-dimensional image display of bones and facial epidermis from an ordinary axial image. Clinically, three-dimensional images were formed at eye sockets and hip joints. With the three-dimensional image using the head phantom, the entire head could be displayed at any angle. Clinically, images were obtained that could not be attained by ordinary CT scanning, such as broken bones in eye sockets and stereoscopic structure at the bottom of a cranium. The three-dimensional image display is considered to be useful in clinical diagnosis. (author)
International Nuclear Information System (INIS)
Patel, Paresh; Sumod, C.B.; Thakkar, Dipal
2011-01-01
Regulated High Voltage Power Supply (RHVPS) system has been developed at Institute for Plasma Research (IPR) for use with the Neutral Beam and RF applications. The highest ratings manufactured so far is 80 kV, 130 A. The system is developed in house and also being delivered at different research institutes for various applications. Since it is a multi megawatt output power system, and the loads have very low fault energy tolerant, fault protection system is mandatory. Protections are mandatory at each stage of conversion. Output fault protection is done in a variety of ways. Fast turn off at output is achieved and test results are discussed. Multi secondary transformers (5.6 MVA rating, with 40 outputs) are used in realising the power supply. These special transformers need protection even for over current at one secondary when the output fault current is not reflected to primaries to break the main circuit breaker. It becomes difficult to bifurcate fault in such situations. Special technique is applied to sense it. Electronic means are used for fast detection and tripping the system. This paper describes the basic RHVPS topology and test results along with presentation on the input and output fault protection systems. (author)
Karimi, Hamid Reza; Gao, Huijun
2008-07-01
A mixed H2/Hinfinity output-feedback control design methodology is presented in this paper for second-order neutral linear systems with time-varying state and input delays. Delay-dependent sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities (LMIs). A controller, which guarantees asymptotic stability and a mixed H2/Hinfinity performance for the closed-loop system of the second-order neutral linear system, is then developed directly instead of coupling the model to a first-order neutral system. A Lyapunov-Krasovskii method underlies the LMI-based mixed H2/Hinfinity output-feedback control design using some free weighting matrices. The simulation results illustrate the effectiveness of the proposed methodology.
Generation and confirmation of a (100 x 100)-dimensional entangled quantum system.
Krenn, Mario; Huber, Marcus; Fickler, Robert; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton
2014-04-29
Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing. Here we present the creation of a (100 × 100)-dimensional entangled quantum system, using spatial modes of photons. For its verification we develop a novel nonlinear criterion which infers entanglement dimensionality of a global state by using only information about its subspace correlations. This allows very practical experimental implementation as well as highly efficient extraction of entanglement dimensionality information. Applications in quantum cryptography and other protocols are very promising.
PC-Link historical data base system MODCOMP/IBM at link for neutral particle beam operation
International Nuclear Information System (INIS)
Thurgood, P.
1989-01-01
PC-Link is a combination of hardware and software that connects an IBM PC/AT to a MODCOMP minicomputer. It is designed as an aid to the Neutral Beam operations coordinator during injection into the DIII-D tokamak project. An IBM PC/AT is linked to 4 MODCOMP realtime acquisition systems, each of which controls 2 neutral particle beam sources. At various points in the shot sequence, data is sent to the IBM PC/AT. This data can then be integrated with the data from the other sources into tables or graphics displays for use by the Beam Coordinator. In this way, the coordinator gets realtime feedback on the relative settings and performance of the sources and can observe trends within a particular source at one location. The PC-Link is used for observing relative timing information and for post shot historical archiving. The concept of the PC-Link was originally proposed several years ago. In April 1988, in-house implementation of the link software was begun. The PC-Link receives approximately 2 Kbytes of data per source per shot. This data is converted from MODCOMP format to IBM PC format and archived to disk. The last 280 shots per source are stored to disk to observe trends. The data can be displayed in a number of formats depending upon the situation. For example, prior to a shot, the beam MODCOMPs are sent timing information from the DIII-D tokamak control system. This data is echoed on the PC in a graphical representation displaying all 8 sources. At the end of the shot, the actual running times are displayed along with the requested settings. Any subset of the Historical data may be displayed either graphically or in tables for realtime comparisons between sources. 4 figs
Institute of Scientific and Technical Information of China (English)
YANG YongHong; WANG YongGang; LIU Mei; WANG Jin
2002-01-01
Two kinds of spin-depcndcnt scattering effects (magnetic-iinpurity and spin-orbit scatterings) axe investi-gated theoretically in a quasi-two-dimensional (quasi-2D) disordered electron system. By making use of the diagrammatictechniques in perturbation theory, we have calculated the dc conductivity and magnetoresistance due to weak-localizationeffects, the analytical expressions of them are obtained as functions of the interlayer hopping energy and the charac-teristic times: elastic, inelastic, magnetic and spin-orbit scattering times. The relevant dimensional crossover behaviorfrom 3D to 2D with decreasing the interlayer coupling is discussed, and the condition for the crossover is shown to bedependent on the aforementioned scattering times. At low temperature there exists a spin-dcpendent-scattering-induccddimensional crossover in this system.
Peng, Chunte Sam; Fedeles, Bogdan I; Singh, Vipender; Li, Deyu; Amariuta, Tiffany; Essigmann, John M; Tokmakoff, Andrei
2015-03-17
Antiviral drugs designed to accelerate viral mutation rates can drive a viral population to extinction in a process called lethal mutagenesis. One such molecule is 5,6-dihydro-5-aza-2'-deoxycytidine (KP1212), a selective mutagen that induces A-to-G and G-to-A mutations in the genome of replicating HIV. The mutagenic property of KP1212 was hypothesized to originate from its amino-imino tautomerism, which would explain its ability to base pair with either G or A. To test the multiple tautomer hypothesis, we used 2D IR spectroscopy, which offers subpicosecond time resolution and structural sensitivity to distinguish among rapidly interconverting tautomers. We identified several KP1212 tautomers and found that >60% of neutral KP1212 is present in the enol-imino form. The abundant proportion of this traditionally rare tautomer offers a compelling structure-based mechanism for pairing with adenine. Additionally, the pKa of KP1212 was measured to be 7.0, meaning a substantial population of KP1212 is protonated at physiological pH. Furthermore, the mutagenicity of KP1212 was found to increase dramatically at pH KP1212 molecules. Overall, our data reveal that the bimodal mutagenic properties of KP1212 result from its unique shape shifting ability that utilizes both tautomerization and protonation.
Three-dimensional oscillator and Coulomb systems reduced from Kaehler spaces
International Nuclear Information System (INIS)
Nersessian, Armen; Yeranyan, Armen
2004-01-01
We define the oscillator and Coulomb systems on four-dimensional spaces with U(2)-invariant Kaehler metric and perform their Hamiltonian reduction to the three-dimensional oscillator and Coulomb systems specified by the presence of Dirac monopoles. We find the Kaehler spaces with conic singularity, where the oscillator and Coulomb systems on three-dimensional sphere and two-sheet hyperboloid originate. Then we construct the superintegrable oscillator system on three-dimensional sphere and hyperboloid, coupled to a monopole, and find their four-dimensional origins. In the latter case the metric of configuration space is a non-Kaehler one. Finally, we extend these results to the family of Kaehler spaces with conic singularities
Energy Technology Data Exchange (ETDEWEB)
Mun, Duhwan, E-mail: dhmun@moeri.re.k [Marine Safety and Pollution Response Research Department, Maritime and Ocean Engineering Research Institute, KORDI, 171 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Yang, Jeongsam, E-mail: jyang@ajou.ac.k [Division of Industrial and Information Systems Engineering, Ajou University, San 5, Wonchun-dong, Yeongtong-gu, Suwon 443-749 (Korea, Republic of)
2010-03-15
How to efficiently integrate and manage lifecycle data of a nuclear power plant has gradually become an important object of study. Because plants usually have a very long period of operation and maintenance, the plant design data need to be presented in a computer-interpretable form and to be independent of any commercial systems. The conversion of plant design data from various design systems into neutral model data is therefore an important technology for the effective operation and maintenance of plants. In this study, a neutral model for the efficient integration of plant design data is chosen from among the currently available options and extended in order to cover the information model requirements of nuclear power plants in Korea. After the mapping of the neutral model and the data model of a specification-driven plant design system, a plant data translator is also implemented in accordance with the schema mapping results.
International Nuclear Information System (INIS)
Mun, Duhwan; Yang, Jeongsam
2010-01-01
How to efficiently integrate and manage lifecycle data of a nuclear power plant has gradually become an important object of study. Because plants usually have a very long period of operation and maintenance, the plant design data need to be presented in a computer-interpretable form and to be independent of any commercial systems. The conversion of plant design data from various design systems into neutral model data is therefore an important technology for the effective operation and maintenance of plants. In this study, a neutral model for the efficient integration of plant design data is chosen from among the currently available options and extended in order to cover the information model requirements of nuclear power plants in Korea. After the mapping of the neutral model and the data model of a specification-driven plant design system, a plant data translator is also implemented in accordance with the schema mapping results.
J.F.A. Braster (Sjaak)
2013-01-01
markdownabstractINTRODUCTION. In the Netherlands, The first national law on education dates back to 1801. It laid the foundation for a system of public education that was accessible to children of all denominations: Protestant, Catholic, and Jewish. The identity of public schools was based on
Simulation of distributed parameter system consisting of charged and neutral particles
International Nuclear Information System (INIS)
Grover, P.S.; Sinha, K.V.
1986-01-01
The time-dependent behavior of positively charged light particles have been simulated in an assembly of heavy gas atoms. The system is formulated in terms of partial differential equation. The stability and convergence of the numerical algorithm has been examined. Using this formulation effects of external electric field and temperature have been investigated on the lifetime and distribution function characteristics of charged particles
Yu, Qilin; Jin, Xiaochen; Zhang, Yaobin
2018-05-15
Sludge cell disruption was generally considered as the rate-limiting step for the anaerobic digestion of waste activated sludge (WAS). Advanced oxidation processes and bio-electro-chemical systems were recently reported to enhance the hydrolysis of WAS and sludge cell disruption, while the cell-breaking processes of these systems remain unclear yet. In this study, an innovative Bio-electro-Fenton system was developed to pretreat the WAS sequentially with cathode Fenton process and anode anaerobic digestion. Significant cell disruption and dissolution intracellular organics were founded after the treatment. X-ray photoelectron spectroscopy (XPS) analysis and fourier transform infrared spectroscopy (FT-IR) spectra indicated that Gram-negative bacteria were more sensitive to free radicals yielded in cathode to induce a chain reaction that destroyed the lipid-contained outer membrane, while Gram-positive bacteria with thick peptidoglycan layer were liable to be biologically decomposed in the anode. Compared with the oxidation of organic matters in the cathode Fenton, the secretion of enzyme increased in the anode which was beneficial to break down the complex matters (peptidoglycans) into simples that were available for anode oxidation by exoelectrogens. The results also showed a possible prospect for the application of this sequential pretreatment in bio-electro-Fenton systems to disrupt sludge cells and enhance the anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.
Development of a three-dimensional radiation dosimetry system
International Nuclear Information System (INIS)
Bero, M.A.
2001-12-01
The direct non-destructive measurement of the radiation absorbed dose in three dimensions is considered to be technically difficult. Accurate determination of the spatial distribution of absorbed dose plays an important role in many applications particularly in medicine. In radiotherapy computer calculations are frequently used to estimate three-dimensional dose distributions in complex geometry, hence a practical dosimetry system able to provide three-dimensional (3-D) integrated measurements is highly desirable for verifying such dose predictions. Magnetic Resonance Imaging (MRI) has been used to visualise 3-D dose distributions, inside two different detector materials, namely the ferrous sulphate gel (Fricke gel) and the polymer gel system. Each of these procedures has its own drawbacks and limitations, and this research project sought to find improvements and alternatives to overcome these problems. Work on the Fricke gel led to an improved preparation procedure employing gelatin gel whose lower melting point reduces the possibility of dissolved oxygen loss. The role of each component was clarified which led to the omission of all unnecessary chemicals such as the sodium chloride and benzoic acid. Initially MRI was the only 3-D readout technique available, however simple relaxometry was used to characterise the detector quantitatively with each modification before employing an MRI scanner to obtain images. Optimisation of the active constituents saves time and effort, and minimises the cost of equipment as well as materials. A serious drawback of the Fricke gel is ion diffusion, which causes blurring of the recorded spatial distribution and much effort was given to attempts to reduce this. However it was concluded that it is possible to slow down ion diffusion but at the cost of detector sensitivity. Therefore the best way of dealing with this problem is by introducing a fast readout technique so that the dose distribution can be recorded before serious
Relativistic band gaps in one-dimensional disordered systems
International Nuclear Information System (INIS)
Clerk, G.J.; McKellar, B.H.J.
1992-01-01
Conditions for the existence of band gaps in a one-dimensional disordered array of δ-function potentials possessing short range order are developed in a relativistic framework. Both Lorentz vector and scalar type potentials are treated. The relationship between the energy gaps and the transmission properties of the array are also discussed. 20 refs., 2 figs
Neutron scattering studies of low dimensional magnetic systems
DEFF Research Database (Denmark)
Hansen, Ursula Bengård
investigated at low temperaturesand in a longitudinal magnetic eld using neutron spectroscopy. Here we observe thehybridisation of the magnon bound states, inherent to the low dimensional nature ofCoCl2 · 2D2O.At higher temperature, signatures which can be attributed to Magnetic Bloch Oscillationsis observed...
Design and fabrication of an ion accelerator for TFTR-type neutral beam systems
International Nuclear Information System (INIS)
Paterson, J.A.; Duffy, T.J.; Haughian, J.M.; Biagi, L.A.; Yee, D.P.
1977-10-01
The design of the prototype 120-keV, 65-A, 0.5-sec ion accelerator for TFTR-type beam systems is described. Details of the manufacture of the constituent parts are given along with descriptions of the major components of the accelerator. Included are the molybdenum grid structures, molybdenum shields, stainless steel hats and the epoxy insulator. Specific manufacturing problems are discussed along with the results of tests to determine the voltage holding capabilities of the assembly
PC-Link historical data base system MODCOMP/IBM at link for neutral particle beam operation
International Nuclear Information System (INIS)
Thurgood, P.
1989-12-01
''PC-Link'' is a combination of hardware and software that connects an IBM PC/AT to a MODCOMP minicomputer. It is designed as an aid to the Neutral Beam operations coordinator during injection into the DIII-D tokamak project. An IBM PC/AT is linked to 4 MODCOMP ''realtime'' acquisition systems, each of which controls 2 neutral particle beam sources. At various points in the shot sequence, data is sent to the IBM PC/AT. This data can then be integrated with the data from the other sources into tables or graphics displays for use by the Beam Coordinator. In this way, the coordinator gets realtime feedback on the relative settings and performance of the sources and can observe trends within a particular source at one location. The PC- Link is used for observing relative timing information and for post shot historical archiving. The concept of the PC-Link was originally proposed several years ago. In April 1988, in-house implementation of the link software was begun. The PC-Link receives approximately 2 Kbytes of data per source per shot. This data is converted from MODCOMP format to IBM PC format and archived to disk. The last 280 shots per source are stored to disk to observe trends. The data can be displayed in a number of formats depending upon the situation. For example, prior to a shot, the beam MODCOMPs are sent timing information from the DIII-D tokamak control system. This data is echoed on the PC in a graphical representation displaying all 8 sources. At the end of the shot, the actual running times are displayed along with the requested settings. Any subset of the Historical data may be displayed either graphically or in tables for realtime comparisons between sources. This system is designed for realtime use, not for complete archiving purposes. This same data is also sent to a VAX computer for full integration into the archive database. This system is easily upgradable and extremely versatile. 4 figs
International Nuclear Information System (INIS)
Etxeberria, A.; Vechiu, I.; Camblong, H.; Kreckelbergh, S.; Bacha, S.
2014-01-01
Highlights: • The control of a hybrid storage system using a Three Level NPC converter is analysed. • A sinusoidal PWM with an offset injection is used to control the storage system. • The operation of the selected converter is analysed in its entire operation range. • The operational limits of the Three Level NPC converter are defined. - Abstract: This work analyses the use of a Three-Level Neutral Point Clamped (3LNPC) converter to control the power flow of a Hybrid Energy Storage System (HESS) and at the same time interconnect it with the common AC bus of a microgrid. Nowadays there is not any storage technology capable of offering a high energy storage capacity, a high power capacity and a fast response at the same time. Therefore, the necessity of hybridising more than one storage technology is a widely accepted idea in order to satisfy the mentioned requirements. This work shows how the operational limits of the 3LNPC converter can be calculated and integrated in a control structure to facilitate an optimal use of the HESS according to the rules fixed by the user
Energy Technology Data Exchange (ETDEWEB)
Jiang, Caichao; Hu, Chundong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China); Wei, Jianglong, E-mail: jlwei@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xie, Yahong; Xu, Yongjian; Liang, Lizhen; Chen, Shiyong; Liu, Sheng; Liu, Zhimin; Xie, Yuanlai [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)
2017-04-15
Highlights: • A supporting power supply system was designed in details for a RF-driven prototype negative ion source at ASIPP. • The RF power supply for plasma generation adopts an all-solid-state power supply structure. • The extraction grid power supply adopts the pulse step modulator (PSM) technology. - Abstract: In order to study the generation and extraction of negative ions for neutral beam injection application, a prototype RF-driven negative ion source and the corresponding test bed are under construction at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The target of the negative ion source is extracting a negation ion beam of 350 A/m{sup 2} for 3600 s plasma duration and 100 s beam duration. According to the required parameters of test bed, the design of power supply system is put forward for earlier study. In this paper, the performance requirements and design schemes of RF power supply for plasma generation, impedance matching network, bias voltage power supply, and extraction voltage power supply for negative beam extraction are introduced in details. The schemes provide a reference for the construction of power supply system and lay a foundation for the next phase of experimental operation.
Neutral signature Walker-VSI metrics
International Nuclear Information System (INIS)
Coley, A; McNutt, D; Musoke, N; Brooks, D; Hervik, S
2014-01-01
We will construct explicit examples of four-dimensional neutral signature Walker (but not necessarily degenerate Kundt) spaces for which all of the polynomial scalar curvature invariants vanish. We then investigate the properties of some particular subclasses of Ricci flat spaces. We also briefly describe some four-dimensional neutral signature Einstein spaces for which all of the polynomial scalar curvature invariants are constant. (paper)
Effects of applying three-dimensional seismic isolation system on the seismic design of FBR
International Nuclear Information System (INIS)
Hirata, Kazuta; Yabana, Shuichi; Kanazawa, Kenji; Matsuda, Akihiro
1997-01-01
In this study conceptional three-dimensional seismic isolation system for fast breeder reactor (FBR) is proposed. Effects of applying three-dimensional seismic isolation system on the seismic design for the FBR equipment are evaluated quantitatively. From the evaluation, it is concluded following effects are expected by applying the three-dimensional seismic isolation system to the FBR and the effects are evaluated quantitatively. (1) Reduction of membrane thickness of the reactor vessel (2) Suppression of uplift of fuels by reducing vertical seismic response of the core (3) Reduction of the supports for the piping system (4) Three-dimensional base isolation system for the whole reactor building is advantageous to the combined isolation system of horizontal base isolation for the reactor building and vertical isolation for the equipment. (author)
A phenomenological study of violation of CP and CPT symmetries in the neutral kaon system
International Nuclear Information System (INIS)
Kojima, Kazushi; Sugiyama, Wataru; Tsai, S.Y.
1996-01-01
A phenomenological study is given of the (possible) violation of CP and CPT symmetries in the K 0 -K-bar 0 system. Special attention is paid to the problem of phase ambiguity and phase convention. Mixing parameters and decay amplitudes are parametrized in a rephasing invariant way, and the well-known parameters η +- and η 00 describing 2π modes as well as various leptonic asymmetries are expressed in terms of these parameters. The parameters ε and Δ characterizing mixing between |K 0 > and |K-bar 0 > are treated with as little theoretical prejudice as possible. (author)
A review of JAERI R and D activities on the negative-ion-based neutral beam injection system
International Nuclear Information System (INIS)
Ohara, Yoshihiro; Akiba, Masato; Araki, Masanori
1990-08-01
R and D efforts to realize a negative-ion-based neutral beam injection system have been made intensively at JAERI for the past several years. Concerning a high current negative ion source which is one of the most important R and D items, a 10 A, 50 keV negative hydrogen ion beam has been produced successfully. The negative ion beam current and the current density correspond already to the value required for the negative-ion-based NBI system. In order to increase the beam energy further, a 350 keV, 0.1 A test stand has been constructed, and the test of a high energy negative ion accelerator has started. Concerning a high energy acceleration power supply, an inverter type power supply which has a high speed AC switch was proposed and applied to the 100 kV, 5 A power supply for JAERI Electron Beam Irradiation Stand. The reliable operation indicates that the concept of this system can be applied for a MV class acceleration power supply. As one of the promising candidates for a beam dump cooling element, an externally-finned swirl tube was proposed and tested to have a high burnout heat flux of 4.1 kW/cm 2 , which is high enough for the next NBI system. The R and Ds on the negative-ion-based NBI system have made great progress at JAERI in recent years. The construction of a 500 keV class NBI system has become realistic from the engineering point of view. (author)
Development of three-dimensional computed tomography system using TNRF2 of JRR-3M
Energy Technology Data Exchange (ETDEWEB)
Murata, Yutaka; Mochiki, Koh-ichi [Musashi Inst. of Tech., Tokyo (Japan); Matsubayashi, Masahito
1998-01-01
A three-dimensional filtering engine, a convolution engine, and a back projection engine were developed for real-time signal processing of three-dimensional computed tomography. The performance of the system was measured and through-put of 0.5 second per one cross sectional data processing was attained. (author)
International Nuclear Information System (INIS)
Chen Jingyun; Cong Peng; Song Qi
2006-01-01
The authors present a new DR image segmentation method based on two-dimensional histogram and watershed algorithm. The authors use watershed algorithm to locate threshold on the vertical projection plane of two-dimensional histogram. This method is applied to the segmentation of DR images produced by luggage inspection system with DR-CT. The advantage of this method is also analyzed. (authors)
International Nuclear Information System (INIS)
Yang Shan; Liu Li; Huang Xiaojing
2014-01-01
In the domestic and abroad standards, the grounding capacitive current limitation in the non-grounding electric auxiliary system is less than 10 A. Limiting capacitive current in the standard aims to speed up the arc extinguishing to reduce the duration of arc over-voltage, but not to prevent the arc producing, The arc over-voltage harm is related to the multiple, frequency and duration of the over-voltage. When the insulation vulnerabilities appear in the equipment, the arc over-voltage may result in insulation vulnerabilities of the electrical equipment breakdown, which leads to multiple, short-circuit accidents. The cable connector, accessory and electromotor winding are all insulation vulnerabilities. Setting the arc suppression coil which can counteract the grounding capacitive current makes the arc vanish quickly. Using the casting bus which remarkably reduces the ground capacitance of the electric transmission line makes the equipment safer. (authors)
Control and synchronisation of a novel seven-dimensional hyperchaotic system with active control
Varan, Metin; Akgul, Akif
2018-04-01
In this work, active control method is proposed for controlling and synchronising seven-dimensional (7D) hyperchaotic systems. The seven-dimensional hyperchaotic system is considered for the implementation. Seven-dimensional hyperchaotic system is also investigated via time series, phase portraits and bifurcation diagrams. For understanding the impact of active controllers on global asymptotic stability of synchronisation and control errors, the Lyapunov function is used. Numerical analysis is done to reveal the effectiveness of applied active control method and the results are discussed.
Topologically protected states in one-dimensional systems
Fefferman, C L; Weinstein, M I
2017-01-01
The authors study a class of periodic Schrödinger operators, which in distinguished cases can be proved to have linear band-crossings or "Dirac points". They then show that the introduction of an "edge", via adiabatic modulation of these periodic potentials by a domain wall, results in the bifurcation of spatially localized "edge states". These bound states are associated with the topologically protected zero-energy mode of an asymptotic one-dimensional Dirac operator. The authors' model captures many aspects of the phenomenon of topologically protected edge states for two-dimensional bulk structures such as the honeycomb structure of graphene. The states the authors construct can be realized as highly robust TM-electromagnetic modes for a class of photonic waveguides with a phase-defect.
Instability of higher dimensional Yang-Mills systems
International Nuclear Information System (INIS)
Randjbar-Daemi, S.; Strathdee, J.
1983-01-01
We investigate the stability of Poincare xO(3) invariant solutions for a pure semi-simple Yang-Mills, as well as Yang-Mills coupled to gravity in 6-dimensional space-time compactified over M 4 xS 2 . In contrast to the Maxwell U(1) theory (IC-82/208) in six dimensions coupled with gravity and investigated previously, the present theory exhibits tachyonic excitations and is unstable. (author)
Suurs, R.A.A.; Hekkert, M.P.; Meeus, M.T.H.; Nieuwlaar, E.
2004-01-01
This paper proposes a method for the ex ante evaluation of technological trajectories. As a case we study the Dutch transport energy system and its transition to climate neutrality. Two technological trajectories are proposed: (i) a sequence of transition steps based on radical infrastructural
Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold
Farmer, Joseph C; Stadermann, Michael
2013-11-12
A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.
On the absence of order in 2-dimensional systems with compact symmetry
International Nuclear Information System (INIS)
Bruschi, M.L.; Garcia, A.A.; Masperi, L.; Garcia Canal, C.A.
1984-01-01
An alternative proof for the generalization to any compact Lie group of the absence of an ordered phase in one and two dimensional classical systems is provided using the original Bogoliubov inequality. (Author) [pt
International Nuclear Information System (INIS)
Ma Songhua; Fang Jianping; Zheng Chunlong
2009-01-01
By means of an extended mapping method and a variable separation method, a series of solitary wave solutions, periodic wave solutions and variable separation solutions to the (2 + 1)-dimensional breaking soliton system is derived.
System and method for three-dimensional image reconstruction using an absolute orientation sensor
Giancola, Silvio; Ghanem, Bernard; Schneider, Jens; Wonka, Peter
2018-01-01
A three-dimensional image reconstruction system includes an image capture device, an inertial measurement unit (IMU), and an image processor. The image capture device captures image data. The inertial measurement unit (IMU) is affixed to the image
Engineering study of the neutral beam and rf heating systems for DIII-D, MFTF-B, JET, JT-60 and TFTR
International Nuclear Information System (INIS)
Lindquist, W.B.; Staten, S.H.
1987-01-01
An engineering study was performed on the rf and neutral beam heating systems implemented for DIII-D, MFTF-B, JET, JT-60 and TFTR. Areas covered include: methodology used to implement the systems, technology, cost, schedule, performance, problems encountered and lessons learned. Systems are compared and contrasted in the areas studied. Summary statements were made on common problems and lessons learned. 3 refs., 6 tabs
International Nuclear Information System (INIS)
Voloschenko, A. M.; Gukov, S. V.; Russkov, A. A.; Gurevich, M. I.; Shkarovsky, D. A.; Kryuchkov, V. P.; Sumaneev, O. V.; Dubinin, A. A.
2009-01-01
KATRIN, KASKAD-Sand ROZ-6 codes solve the multigroup transport equation for neutrons, photons and charged particles in 3D. BOT3P-5., ConDat can be used as preprocessor. ARVES-2.5, a cross-section preprocessor (the package of utilities for operating with the cross section file in FMAC-M format) is included. Auxiliary codes MIXERM, CEPXS-BFP, CEPXS-BFP, SADCO-2.4 and CNCSN-2 are used
Three-dimensional micro electromechanical system piezoelectric ultrasound transducer
Hajati, Arman; Latev, Dimitre; Gardner, Deane; Hajati, Azadeh; Imai, Darren; Torrey, Marc; Schoeppler, Martin
2012-12-01
Here we present the design and experimental acoustic test data for an ultrasound transducer technology based on a combination of micromachined dome-shaped piezoelectric resonators arranged in a flexible architecture. Our high performance niobium-doped lead zirconate titanate film is implemented in three-dimensional dome-shaped structures, which form the basic resonating cells. Adjustable frequency response is realized by mixing these basic cells and modifying their dimensions by lithography. Improved characteristics such as high sensitivity, adjustable wide-bandwidth frequency response, low transmit voltage compatible with ordinary integrated circuitry, low electrical impedance well matched to coaxial cabling, and intrinsic acoustic impedance match to water are demonstrated.
Three-Dimensional Design of a Non-Axisymmetric Periodic Permanent Magnet Focusing System
Chen Chi Ping; Radovinsky, Alexey; Zhou, Jing
2005-01-01
A three-dimensional (3D) design is presented of a non-axisymmetric periodic permanent magnet focusing system which will be used to focus a large-aspect-ratio, ellipse-shaped, space-charge-dominated electron beam. In this design, an analytic theory is used to specify the magnetic profile for beam transport. The OPERA3D code is used to compute and optimize a realizable magnet system. Results of the magnetic design are verified by two-dimensional particle-in-cell and three-dimensional trajectory simulations of beam propagation using PFB2D and OMNITRAK, respectively. Results of fabrication tolerance studies are discussed.
On the generating function of Poincare plots defining one dimensional perturbed Hamiltonian systems
International Nuclear Information System (INIS)
Montvai, A.
1989-01-01
A simple numerical method has been devised, for deriving the generating function of an arbitrary, one dimensional Hamiltonian system represented by its Poincare plot. In this case, the plot to be numerically processed is an area preserving transformation of a two-dimensional surface onto itself. Although the method in its present form is capable of treating only this case, there are no principal restrictions excluding the analysis of systems with higher dimensionality as well. As an example, the generating function of the motion of alpha particles in a nonsymmetric, toroidal magnetic field is derived and studied numerically. (orig.)
International Nuclear Information System (INIS)
Zheng Chunlong; Qiang Jiye; Wang Shaohua
2010-01-01
In the paper, the variable separation approach, homoclinic test technique and bilinear method are successfully extended to a (1 + 1)-dimensional Caudry-Dodd-Gibbon-Sawada-Kortera (CDGSK) system, respectively. Based on the derived exact solutions, some significant types of localized excitations such as standing waves, periodic waves, solitary waves are simultaneously derived from the (1 + 1)-dimensional Caudry-Dodd-Gibbon-Sawada-Kortera system by entrancing appropriate parameters. (general)
Magnetoresistance of amorphous CuZr: weak localization in a three dimensional system
International Nuclear Information System (INIS)
Bieri, J.B.; Fert, A.; Creuzet, G.
1984-01-01
Observations of anomalous magnetoresistance in amorphous CuZr at low temperature are reported. The magnetoresistance can be precisely accounted for in theoretical models of localization for 3-dimensional metallic systems in the presence of strong spin-orbit interactions (with a significant additional contribution from the quenching of superconducting fluctuations at the lowest temperatures). Magnetoresistance measurements on various other systems show that such 3-dimensional localization effects are very generally observed in amorphous alloys. (author)
Energy Technology Data Exchange (ETDEWEB)
Rakotozafy, Mamianja [Groupe de Recherches en Electrotechnique et Electronique de Nancy (GREEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); CONVERTEAM SAS, Parc d' activites Techn' hom, 24 avenue du Marechal Juin, BP 40437, 90008 Belfort Cedex (France); Poure, Philippe [Laboratoire d' Instrumentation Electronique de Nancy (LIEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); Saadate, Shahrokh [Groupe de Recherches en Electrotechnique et Electronique de Nancy (GREEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); Bordas, Cedric; Leclere, Loic [CONVERTEAM SAS, Parc d' activites Techn' hom, 24 avenue du Marechal Juin, BP 40437, 90008 Belfort Cedex (France)
2011-02-15
Most of actual real time simulation platforms have practically about ten microseconds as minimum calculation time step, mainly due to computation limits such as processing speed, architecture adequacy and modeling complexities. Therefore, simulation of fast switching converters' instantaneous models requires smaller computing time step. The approach presented in this paper proposes an answer to such limited modeling accuracies and computational bandwidth of the currently available digital simulators.As an example, the authors present a low cost, flexible and high performance FPGA-based real-time digital simulator for a complete complex power system with Neutral Point Piloted (NPP) three-level inverter. The proposed real-time simulator can model accurately and efficiently the complete power system, reducing costs, physical space and avoiding any damage to the actual equipment in the case of any dysfunction of the digital controller prototype. The converter model is computed at a small fixed time step as low as 100 ns. Such a computation time step allows high precision account of the gating signals and thus avoids averaging methods and event compensations. Moreover, a novel high performance model of the NPP three-level inverter has also been proposed for FPGA implementation. The proposed FPGA-based simulator models the environment of the NPP converter: the dc link, the RLE load and the digital controller and gating signals. FPGA-based real time simulation results are presented and compared with offline results obtained using PLECS software. They validate the efficiency and accuracy of the modeling for the proposed high performance FPGA-based real-time simulation approach. This paper also introduces new potential FPGA-based applications such as low cost real time simulator for power systems by developing a library of flexible and portable models for power converters, electrical machines and drives. (author)
Neutral particle transport modeling with a reflective source in the plasma edge
International Nuclear Information System (INIS)
Valenti, M.E.
1992-01-01
A reflective source term is incorporated into the Boltzmann neutral particle transport equation to account for boundary reflection. This reflective neutral model is integrated over a uniform axis and subsequently discretized. The discrete two-dimensional equations are solved iteratively with a computer code. The results of the reflective neutral model computer code are benchmarked with the neutral particle transport code ONEDANT. The benchmark process demonstrates the validity of the reflective neutral model. The reflective neutral model is coupled to the Braams plasma particle and energy transport code. The coupled system generates self-consistent plasma edge transport solutions. These solutions, which utilize the transport equation are similar to solutions which utilize simple plasma edge neutral models when high recycle divertors are modeled. In the high recycle mode, the high electron density at the divertor plate reduces the mean free path of plate neutrals. Hence, the similarity in results. It is concluded that simple neutral models are sufficient for the analysis of high recycle power reactor edge plasmas. Low recycle edge plasmas were not examined
Unlabored system motion by specially conditioned electromagnetic fields in higher dimensional realms
David Froning, H.; Meholic, Gregory V.
2010-01-01
This third of three papers explores the possibility of swift, stress-less system transitions between slower-than-light and faster-than-light speeds with negligible net expenditure of system energetics. The previous papers derived a realm of higher dimensionality than 4-D spacetime that enabled such unlabored motion; and showed that fields that could propel and guide systems on unlabored paths in the higher dimensional realm must be fields that have been conditioned to SU(2) (or higher) Lie group symmetry. This paper shows that the system's surrounding vacuum dielectric ɛμ, within the higher dimensional realm's is a vector (not scalar) quantity with fixed magnitude ɛ0μ0 and changing direction within the realm with changing system speed. Thus, ɛμ generated by the system's EM field must remain tuned to vacuum ɛ0μ0 in both magnitude and direction during swift, unlabored system transitions between slower and faster than light speeds. As a result, the system's changing path and speed is such that the magnitude of the higher dimensional realm's ɛ0μ0 is not disturbed. And it is shown that a system's flight trajectories associated with its swift, unlabored transitions between zero and infinite speed can be represented by curved paths traced-out within the higher dimensional realm.
On Interconnections of Infinite-dimensional Port-Hamiltonian Systems
Pasumarthy, Ramkrishna; Schaft, Arjan J. van der
2004-01-01
Network modeling of complex physical systems leads to a class of nonlinear systems called port-Hamiltonian systems, which are defined with respect to a Dirac structure (a geometric structure which formalizes the power-conserving interconnection structure of the system). A power conserving
On interconnections of infinite-dimensional port-Hamiltonian systems
Ramkrishna Pasumarthy, R.P.; van der Schaft, Arjan
2004-01-01
Network modeling of complex physical systems leads to a class of nonlinear systems called port-Hamiltonian systems, which are defined with respect to a Dirac structure (a geometric structure which formalizes the power-conserving interconnection structure of the system). A power conserving
Lindsay, Alexander; Anderson, Carly; Slikboer, Elmar; Shannon, Steven; Graves, David
2015-10-01
There is a growing interest in the study of plasma-liquid interactions with application to biomedicine, chemical disinfection, agriculture, and other fields. This work models the momentum, heat, and neutral species mass transfer between gas and aqueous phases in the context of a streamer discharge; the qualitative conclusions are generally applicable to plasma-liquid systems. The problem domain is discretized using the finite element method. The most interesting and relevant model result for application purposes is the steep gradients in reactive species at the interface. At the center of where the reactive gas stream impinges on the water surface, the aqueous concentrations of OH and ONOOH decrease by roughly 9 and 4 orders of magnitude respectively within 50 μ m of the interface. Recognizing the limited penetration of reactive plasma species into the aqueous phase is critical to discussions about the therapeutic mechanisms for direct plasma treatment of biological solutions. Other interesting results from this study include the presence of a 10 K temperature drop in the gas boundary layer adjacent to the interface that arises from convective cooling. Though the temperature magnitudes may vary among atmospheric discharge types (different amounts of plasma-gas heating), this relative difference between gas and liquid bulk temperatures is expected to be present for any system in which convection is significant. Accounting for the resulting difference between gas and liquid bulk temperatures has a significant impact on reaction kinetics; factor of two changes in terminal aqueous species concentrations like H2O2, NO2- , and NO3- are observed in this study if the effect of evaporative cooling is not included.
International Nuclear Information System (INIS)
Franzen, P.; Fantz, U.
2014-01-01
Highlights: • NBI is a candidate for a cw tokamak DEMO due to its high current drive efficiency. • The plug-in efficiency must be improved from the present 20–30% to more than 50%. • A suitable candidate is a photo neutralizer with almost 100% neutralization efficiency; basic feasibility studies are underway. • Cw operation with a large availability puts rather high demands on source operation with some safety margins, especially for the components with high power density loads (source back plate and extraction system). • Alternatives to the present use of cesium are under exploitations. - Abstract: The requirements for the heating and current drive systems of a fusion power plant will strongly depend on the DEMO scenario. The paper discusses the R and D needs for a neutral beam injection system — being a candidate due to the highest current drive efficiency — for the most demanding scenario, a steady state tokamak DEMO. Most important issues are the improvement of the wall-plug efficiency from the present ∼25% to the required 50–60% by improving the neutralization efficiency with a laser neutralizer system and the improvement of the reliability of the ion source operation. The demands on and the potential of decreasing the ion source operation pressure, as well as decreasing the amount of co-extracted electrons and backstreaming ions are discussed using the ITER requirements and solutions as basis. A further concern is the necessity of cesium for which either the cesium management must be improved or alternatives to cesium for the production of negative ions have to be identified
Pattern formation in three-dimensional reaction-diffusion systems
Callahan, T. K.; Knobloch, E.
1999-08-01
Existing group theoretic analysis of pattern formation in three dimensions [T.K. Callahan, E. Knobloch, Symmetry-breaking bifurcations on cubic lattices, Nonlinearity 10 (1997) 1179-1216] is used to make specific predictions about the formation of three-dimensional patterns in two models of the Turing instability, the Brusselator model and the Lengyel-Epstein model. Spatially periodic patterns having the periodicity of the simple cubic (SC), face-centered cubic (FCC) or body-centered cubic (BCC) lattices are considered. An efficient center manifold reduction is described and used to identify parameter regimes permitting stable lamellæ, SC, FCC, double-diamond, hexagonal prism, BCC and BCCI states. Both models possess a special wavenumber k* at which the normal form coefficients take on fixed model-independent ratios and both are described by identical bifurcation diagrams. This property is generic for two-species chemical reaction-diffusion models with a single activator and inhibitor.
Charge and spin separation in one-dimensional systems
International Nuclear Information System (INIS)
Balseiro, C.A.; Jagla, E.A.; Hallberg, K.
1995-01-01
In this article we discuss charge and spin separation and quantum interference in one-dimensional models. After a short introduction we briefly present the Hubbard and Luttinger models and discuss some of the known exact results. We study numerically the charge and spin separation in the Hubbard model. The time evolution of a wave packet is obtained and the charge and spin densities are evaluated for different times. The charge and spin wave packets propagate with different velocities. The results are interpreted in terms of the Bethe-ansatz solution. In section IV we study the effect of charge and spin separation on the quantum interference in a Aharonov-Bohm experiment. By calculating the one-particle propagators of the Luttinger model for a mesoscopic ring with a magnetic field we calculate the Aharonov-Bohm conductance. The conductance oscillates with the magnetic field with a characteristic frequency that depends on the charge and spin velocities. (author)
Three New (2+1)-dimensional Integrable Systems and Some Related Darboux Transformations
International Nuclear Information System (INIS)
Guo Xiu-Rong
2016-01-01
We introduce two operator commutators by using different-degree loop algebras of the Lie algebra A 1 , then under the framework of zero curvature equations we generate two (2+1)-dimensional integrable hierarchies, including the (2+1)-dimensional shallow water wave (SWW) hierarchy and the (2+1)-dimensional Kaup-Newell (KN) hierarchy. Through reduction of the (2+1)-dimensional hierarchies, we get a (2+1)-dimensional SWW equation and a (2+1)-dimensional KN equation. Furthermore, we obtain two Darboux transformations of the (2+1)-dimensional SWW equation. Similarly, the Darboux transformations of the (2+1)-dimensional KN equation could be deduced. Finally, with the help of the spatial spectral matrix of SWW hierarchy, we generate a (2+1) heat equation and a (2+1) nonlinear generalized SWW system containing inverse operators with respect to the variables x and y by using a reduction spectral problem from the self-dual Yang-Mills equations. (paper)
Three New (2+1)-dimensional Integrable Systems and Some Related Darboux Transformations
Guo, Xiu-Rong
2016-06-01
We introduce two operator commutators by using different-degree loop algebras of the Lie algebra A1, then under the framework of zero curvature equations we generate two (2+1)-dimensional integrable hierarchies, including the (2+1)-dimensional shallow water wave (SWW) hierarchy and the (2+1)-dimensional Kaup-Newell (KN) hierarchy. Through reduction of the (2+1)-dimensional hierarchies, we get a (2+1)-dimensional SWW equation and a (2+1)-dimensional KN equation. Furthermore, we obtain two Darboux transformations of the (2+1)-dimensional SWW equation. Similarly, the Darboux transformations of the (2+1)-dimensional KN equation could be deduced. Finally, with the help of the spatial spectral matrix of SWW hierarchy, we generate a (2+1) heat equation and a (2+1) nonlinear generalized SWW system containing inverse operators with respect to the variables x and y by using a reduction spectral problem from the self-dual Yang-Mills equations. Supported by the National Natural Science Foundation of China under Grant No. 11371361, the Shandong Provincial Natural Science Foundation of China under Grant Nos. ZR2012AQ011, ZR2013AL016, ZR2015EM042, National Social Science Foundation of China under Grant No. 13BJY026, the Development of Science and Technology Project under Grant No. 2015NS1048 and A Project of Shandong Province Higher Educational Science and Technology Program under Grant No. J14LI58
Viazzi, S.; Bahr, C.; Hertem, van T.; Schlageter-Tello, A.; Romanini, C.E.B.; Halachmi, I.; Lokhorst, C.; Berckmans, D.
2014-01-01
In this study, two different computer vision techniques to automatically measure the back posture in dairy cows were tested and evaluated. A two-dimensional and a three-dimensional camera system were used to extract the back posture from walking cows, which is one measurement used by experts to
International Nuclear Information System (INIS)
Wang Lei; Yang Ming; Li Guanghua; Shi Zhan; Feng Shouhua
2006-01-01
Employing 4,4'-bipyridine as a bridged ligand, a new three-dimensional (3-D) hybrid zinc phosphate [Zn 2 (HPO 4 ) 2 (4,4'-bipy)].3H 2 O has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group C2/c, with cell parameters, a=21.188(4)A, b=10.229(2)A, c=9.0656(18)A, β=90.21(3) o , V=1964.8(7)A 3 and Z=4. The connectivity of the ZnO 3 N and HPO 4 tetrahedra results in a 2-D neutral layer that with interesting 4,8 2 net along the bc plane. Furthermore, the 4,4'-bipyridine molecule links the 4,8 2 net into a 3-D structure. The water molecules sit in the middle of the channels and interact with the framework via hydrogen bonds. The compound exhibits intense photoluminescence at room temperature
International Nuclear Information System (INIS)
Gribble, R.
1993-06-01
A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described
Negative ion based neutral beams for plasma heating
International Nuclear Information System (INIS)
Prelec, K.
1978-01-01
Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored
Rational solutions to two- and one-dimensional multicomponent Yajima–Oikawa systems
International Nuclear Information System (INIS)
Chen, Junchao; Chen, Yong; Feng, Bao-Feng; Maruno, Ken-ichi
2015-01-01
Exact explicit rational solutions of two- and one-dimensional multicomponent Yajima–Oikawa (YO) systems, which contain multi-short-wave components and single long-wave one, are presented by using the bilinear method. For two-dimensional system, the fundamental rational solution first describes the localized lumps, which have three different patterns: bright, intermediate and dark states. Then, rogue waves can be obtained under certain parameter conditions and their behaviors are also classified to above three patterns with different definition. It is shown that the simplest (fundamental) rogue waves are line localized waves which arise from the constant background with a line profile and then disappear into the constant background again. In particular, two-dimensional intermediate and dark counterparts of rogue wave are found with the different parameter requirements. We demonstrate that multirogue waves describe the interaction of several fundamental rogue waves, in which interesting curvy wave patterns appear in the intermediate times. Different curvy wave patterns form in the interaction of different types fundamental rogue waves. Higher-order rogue waves exhibit the dynamic behaviors that the wave structures start from lump and then retreat back to it, and this transient wave possesses the patterns such as parabolas. Furthermore, different states of higher-order rogue wave result in completely distinguishing lumps and parabolas. Moreover, one-dimensional rogue wave solutions with three states are constructed through the further reduction. Specifically, higher-order rogue wave in one-dimensional case is derived under the parameter constraints. - Highlights: • Exact explicit rational solutions of two-and one-dimensional multicomponent Yajima–Oikawa systems. • Two-dimensional rogue wave contains three different patterns: bright, intermediate and dark states. • Multi- and higher-order rogue waves exhibit distinct dynamic behaviors in two-dimensional case
Numerical Three-Dimensional Model of Airport Terminal Drainage System
Strzelecki Michał
2014-01-01
During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary wate...
Nambu-Poisson reformulation of the finite dimensional dynamical systems
International Nuclear Information System (INIS)
Baleanu, D.; Makhaldiani, N.
1998-01-01
A system of nonlinear ordinary differential equations which in a particular case reduces to Volterra's system is introduced. We found in two simplest cases the complete sets of the integrals of motion using Nambu-Poisson reformulation of the Hamiltonian dynamics. In these cases we have solved the systems by quadratures
Computation of focal values and stability analysis of 4-dimensional systems
Directory of Open Access Journals (Sweden)
Bo Sang
2015-08-01
Full Text Available This article presents a recursive formula for computing the n-th singular point values of a class of 4-dimensional autonomous systems, and establishes the algebraic equivalence between focal values and singular point values. The formula is linear and then avoids complicated integrating operations, therefore the calculation can be carried out by computer algebra system such as Maple. As an application of the formula, bifurcation analysis is made for a quadratic system with a Hopf equilibrium, which can have three small limit cycles around an equilibrium point. The theory and methodology developed in this paper can be used for higher-dimensional systems.
Impurity states in two-and three-dimensional disordered systems
International Nuclear Information System (INIS)
Silva, A.F. da; Fabbri, M.
1984-04-01
The microscopic structure of the impurity states in two-and three-dimensional (2D and 3D) disordered systems is investigated. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e., from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (Author) [pt
International Nuclear Information System (INIS)
Li Zhu; Dong Huanhe
2008-01-01
Under the frame of the (2 + 1)-dimensional zero curvature equation and Tu model, (2 + 1)-dimensional Dirac hierarchy is obtained. Again by use of the expanding loop algebra the integrable coupling system of the above hierarchy is given
Generation and confirmation of a (100 × 100)-dimensional entangled quantum system
Krenn, Mario; Huber, Marcus; Fickler, Robert; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton
2014-01-01
Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing. Here we present the creation of a (100 × 100)-dimensional entangled quantum system, using spatial modes of photons. For its verification we develop a novel nonlinear criterion which infers entanglement dimensionality of a global state by using only information about its subspace correlations. This allows very practical experimental implementation as well as highly efficient extraction of entanglement dimensionality information. Applications in quantum cryptography and other protocols are very promising. PMID:24706902
Directory of Open Access Journals (Sweden)
V. A. Trudonoshin
2015-01-01
Full Text Available The article proposes a technique to develop mathematical models (MM of elements of the three-dimensional (3D mechanical systems for universal simulation software systems that allow us automatically generate the MM of a system based on MM elements and their connections. The technique is based on the MM of 3 D body. Linear and angular velocities are used as the main phase variables (unknown in the MM of the system, linear and angular movements are used as the additional ones, the latter being defined by the normalized quaternions that have computational advantages over turning angles.The paper has considered equations of dynamics, formulas of transition from the global coordinate system to the local one and vice versa. A spherical movable joint is presented as an example of the interaction element between the bodies. The paper shows the MM equivalent circuits of a body and a spherical joint. Such a representation, as the equivalent circuit, automatically enables us to obtain topological equations of the system. Various options to build equations of the joint and advices for their practical use are given.
Optimization Techniques for Dimensionally Truncated Sparse Grids on Heterogeneous Systems
Deftu, A.
2013-02-01
Given the existing heterogeneous processor landscape dominated by CPUs and GPUs, topics such as programming productivity and performance portability have become increasingly important. In this context, an important question refers to how can we develop optimization strategies that cover both CPUs and GPUs. We answer this for fastsg, a library that provides functionality for handling efficiently high-dimensional functions. As it can be employed for compressing and decompressing large-scale simulation data, it finds itself at the core of a computational steering application which serves us as test case. We describe our experience with implementing fastsg\\'s time critical routines for Intel CPUs and Nvidia Fermi GPUs. We show the differences and especially the similarities between our optimization strategies for the two architectures. With regard to our test case for which achieving high speedups is a "must" for real-time visualization, we report a speedup of up to 6.2x times compared to the state-of-the-art implementation of the sparse grid technique for GPUs. © 2013 IEEE.
Quantum one dimensional spin systems. Disorder and impurities
International Nuclear Information System (INIS)
Brunel, V.
1999-01-01
This thesis presents three studies that are respectively the spin-1 disordered chain, the non magnetic impurities in the spin-1/2 chain and the reaction-diffusion process. The spin-1 chain of weak disorder is performed by the Abelian bosonization and the renormalization group. This allows to take into account the competition between the disorder and the interactions and predicts the effects of various spin-1 anisotropy chain phases under many different disorders. A second work uses the non magnetic impurities as local probes of the correlations in the spin-1/2 chain. When the impurities are connected to the chain boundary, the author predicts a temperature dependence of the relaxation rate (1/T) of the nuclear spin impurities, different from the case of these impurities connected to the whole chain. The last work deals with one dimensional reaction-diffusion problem. The Jordan-Wigner transformation allows to consider a fermionic field theory that critical exponents follow from the renormalization group. (A.L.B.)
Numerical Three-Dimensional Model of Airport Terminal Drainage System
Directory of Open Access Journals (Sweden)
Strzelecki Michał
2014-03-01
Full Text Available During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.
Development of CANDU fuel in-bay inspection and dimensional measurement system
Energy Technology Data Exchange (ETDEWEB)
Jo, Chang Keun; Cho, Moon Sung; Suk, Ho Chun; Koo, Dae Seo; Park, Kwang June; Jun, Ji Su; Jung, Jong Yeob
2004-09-01
In this report, we describe a spent fuel inspection and dimensional measuring system for CANDU fuel bundles in atmosphere or water. The submissible camera with radiation resistance was used to inspect a spent fuel in water. The design criteria of the dimensional measuring system was set up {+-}0.01mm(10{mu}m) for measuring accuracy. The LVDT (Linear Variable Differential Transformer) was used as measuring sensor in this dimensional measuring system. An LVDT calibration equipment was developed in order to satisfy the required accuracy of the system. Also, aluminum master and CANDU Master with same dimension of fuel bundle was made to calibrate the mechanical error of the dimensional measuring system. The accuracy of the fuel inspection system was examined. The results show that the accuracy in dimensional measurement of fuel rod profile and bearing pad profile, diameter of fuel bundle, fuel rod length, and end plate profile using standard test equipment satisfies the design criteria, i.e., maximum measurement error of {+-}0.01mm(10{mu}m)
Finite cluster renormalization group for disordered two-dimensional systems
International Nuclear Information System (INIS)
El Kenz, A.
1987-09-01
A new type of renormalization group theory using the generalized Callen identities is exploited in the study of the disordered systems. Bond diluted and frustrated Ising systems on a square lattice are analyzed with this new scheme. (author). 9 refs, 2 figs, 2 tabs
Phasons and amplitudons in one dimensional incommensurate systems
International Nuclear Information System (INIS)
Weissmann, M.; Cohan, N.
1982-08-01
There has been recently great interest in two particular vibrational modes of incommensurate (I) systems: phasons and amplitudons. In this letter we show that for a 1D incommensurate system phasons and amplitudons can be obtained with the simplest possible model: that of harmonic interactions between first neighbours only, provided that a realistic dependence of the force constants k with distance r is used
International Nuclear Information System (INIS)
Knoll, D.A.; McHugh, P.R.; Krasheninnikov, S.I.; Sigmar, D.J.
1996-01-01
A combined edge plasma/Navier-Stokes neutral transport model is used to simulate dissipative divertor plasmas in the collisional limit for neutrals on a simplified two-dimensional slab geometry with ITER-like plasma conditions and scale lengths. The neutral model contains three momentum equations which are coupled to the plasma through ionization, recombination, and ion-neutral elastic collisions. The neutral transport coefficients are evaluated including both ion-neutral and neutral-neutral collisions. (orig.)
International Nuclear Information System (INIS)
Yabana, Shuichi; Matsuda, Akihiro
2003-01-01
In this study, design procedure on three-dimensional base isolation system is developed. Base isolation system proposed by CRIEPI uses thick rubber bearing and damper as isolation device. As for thick rubber bearings, design formula for evaluating vertical stiffness is proposed, and design conditions regarding size and vertical pressure are investigated. Figure-U type lead damper is proposed as three-dimensional damper and by loading tests its mechanical characteristics is evaluated. The concept of multi-layered interconnected rubber bearing, which is advantageous over large scale bearing in manufacturability, is proposed and its good performance is confirmed by the loading test. Through the response analyses, it is shown the rocking response of the proposed three-dimensional base isolation system is very small and not influential to the system, and the reduction of the vertical response is attained using the proposed isolation device. (author)
Quantum magnetism in strongly interacting one-dimensional spinor Bose systems
DEFF Research Database (Denmark)
Salami Dehkharghani, Amin; Volosniev, A. G.; Lindgren, E. J.
2015-01-01
-range inter-species interactions much larger than their intra-species interactions and show that they have novel energetic and magnetic properties. In the strongly interacting regime, these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated......Strongly interacting one-dimensional quantum systems often behave in a manner that is distinctly different from their higher-dimensional counterparts. When a particle attempts to move in a one-dimensional environment it will unavoidably have to interact and 'push' other particles in order...... ground states with manifestly ferromagnetic wave functions. Furthermore, we predict excited states that have perfect antiferromagnetic ordering. This holds for both balanced and imbalanced systems, and we show that it is a generic feature as one crosses from few- to many-body systems....
Edwards, Warren S.; Ritchie, Cameron J.; Kim, Yongmin; Mack, Laurence A.
1995-04-01
We have developed a three-dimensional (3D) imaging system using power Doppler (PD) ultrasound (US). This system can be used for visualizing and analyzing the vascular anatomy of parenchymal organs. To create the 3D PD images, we acquired a series of two-dimensional PD images from a commercial US scanner and recorded the position and orientation of each image using a 3D magnetic position sensor. Three-dimensional volumes were reconstructed using specially designed software and then volume rendered for display. We assessed the feasibility and geometric accuracy of our system with various flow phantoms. The system was then tested on a volunteer by scanning a transplanted kidney. The reconstructed volumes of the flow phantom contained less than 1 mm of geometric distortion and the 3D images of the transplanted kidney depicted the segmental, arcuate, and interlobar vessels.
On the conductivity of a one-dimensional system of interacting fermions in a random potential
International Nuclear Information System (INIS)
Apel, W.
1981-01-01
A one-dimensional system of interacting fermions in an external potential is studied. The problem was for this purpose transformed to two classical models of statistical mechanics in two dimensions in which occasionally results were found in complementary ranges of the interaction constants of the fermion system. The conductivity appeared as a simple correlation function in both classical models. It was shown that the interaction in a one-dimensional polluted fermion system can cause an isolator-metal transition. (orig./HSI) [de
Hopping transport and electrical conductivity in one-dimensional systems with off-diagonal disorder
International Nuclear Information System (INIS)
Ma Songshan; Xu Hui; Li Yanfeng; Song Zhaoquan
2007-01-01
In this paper, we present a model to describe hopping transport and electrical conductivity of one-dimensional systems with off-diagonal disorder, in which electrons are transported via hopping between localized states. We find that off-diagonal disorder leads to delocalization and drastically enhances the electrical conductivity of systems. The model also quantitatively explains the temperature and electrical field dependence of the conductivity in one-dimensional systems with off-diagonal disorder. In addition, we also show the dependence of the conductivity on the strength of off-diagonal disorder
Multi-dimensional database design and implementation of dam safety monitoring system
Directory of Open Access Journals (Sweden)
Zhao Erfeng
2008-09-01
Full Text Available To improve the effectiveness of dam safety monitoring database systems, the development process of a multi-dimensional conceptual data model was analyzed and a logic design was achieved in multi-dimensional database mode. The optimal data model was confirmed by identifying data objects, defining relations and reviewing entities. The conversion of relations among entities to external keys and entities and physical attributes to tables and fields was interpreted completely. On this basis, a multi-dimensional database that reflects the management and analysis of a dam safety monitoring system on monitoring data information has been established, for which factual tables and dimensional tables have been designed. Finally, based on service design and user interface design, the dam safety monitoring system has been developed with Delphi as the development tool. This development project shows that the multi-dimensional database can simplify the development process and minimize hidden dangers in the database structure design. It is superior to other dam safety monitoring system development models and can provide a new research direction for system developers.
DEFF Research Database (Denmark)
Dahl, Rasmus H; Berg, Ronan M G; Taudorf, Sarah
2018-01-01
We reassessed data from a previous study on the transcerebral net exchange of large neutral amino acids (LNAAs) using a novel mathematical model of blood-brain barrier (BBB) transport. The study included twelve healthy volunteers who received a 4-h intravenous lipopolysaccharide (LPS) infusion...
Lindsay, A.; Anderson, C.; Slikboer, E.T.; Shannon, S.; Graves, D.
2015-01-01
There is a growing interest in the study of plasma-liquid interactions with application to biomedicine, chemical disinfection, agriculture, and other fields. This work models the momentum, heat, and neutral species mass transfer between gas and aqueous phases in the context of a streamer discharge;
K-intercalated carbon systems: Effects of dimensionality and substrate
Kaloni, Thaneshwor P.
2012-06-01
Density functional theory is employed to investigate the electronic properties of K-intercalated carbon systems. Young\\'s modulus indicates that the intercalation increases the intrinsic stiffness. For K-intercalated bilayer graphene on SiC(0001) the Dirac cone is maintained, whereas a trilayer configuration exhibits a small splitting at the Dirac point. Interestingly, in contrast to many other intercalated carbon systems, the presence of the SiC(0001) substrate does not suppress but rather enhances the charge carrier density. Reasonably high values are found for all systems, the highest carrier density for the bilayer. The band structure and electron-phonon coupling of free-standing K-intercalated bilayer graphene points to a high probability for superconductivity in this system. © 2012 Europhysics Letters Association.
International Nuclear Information System (INIS)
Li Jinpo; Ai Zhihui; Zhang Lizhi
2009-01-01
The narrow pH range limits the wide application of Fenton reaction in the wastewater treatment. It is of great importance to widen working pH range of Fenton reaction from strong acidic condition to neutral, even basic ones. In this study, for the first time nanostructured Fe-Fe 2 O 3 was loaded on active carbon fiber (ACF) as an oxygen diffusion cathode to be used in a heterogeneous electro-Fenton (E-Fenton) oxidation system. This novel Fe-Fe 2 O 3 /ACF composite cathode was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and element mapping. On the degradation of dye pollutant rhodamine B in water, this heterogeneous E-Fenton system with the Fe-Fe 2 O 3 /ACF cathode showed much higher activity than other E-Fenton systems with commercial zero valent iron powders (Fe 0 ) and ferrous ions (Fe 2+ ) under neutral pH. On the basis of experimental results, we proposed a possible pathway of rhodamine B degradation in this heterogeneous Fe-Fe 2 O 3 /ACF E-Fenton process. This heterogeneous E-Fenton system is very promising to remove organic pollutants in water at neutral pH
Directory of Open Access Journals (Sweden)
William B Messer
Full Text Available Dengue viruses (DENV are enveloped single-stranded positive-sense RNA viruses transmitted by Aedes spp. mosquitoes. There are four genetically distinct serotypes designated DENV-1 through DENV-4, each further subdivided into distinct genotypes. The dengue scientific community has long contended that infection with one serotype confers lifelong protection against subsequent infection with the same serotype, irrespective of virus genotype. However this hypothesis is under increased scrutiny and the role of DENV genotypic variation in protection from repeated infection is less certain. As dengue vaccine trials move increasingly into field-testing, there is an urgent need to develop tools to better define the role of genotypic variation in DENV infection and immunity. To better understand genotypic variation in DENV-3 neutralization and protection, we designed and constructed a panel of isogenic, recombinant DENV-3 infectious clones, each expressing an envelope glycoprotein from a different DENV-3 genotype; Philippines 1982 (genotype I, Thailand 1995 (genotype II, Sri Lanka 1989 and Cuba 2002 (genotype III and Puerto Rico 1977 (genotype IV. We used the panel to explore how natural envelope variation influences DENV-polyclonal serum interactions. When the recombinant viruses were tested in neutralization assays using immune sera from primary DENV infections, neutralization titers varied by as much as ∼19-fold, depending on the expressed envelope glycoprotein. The observed variability in neutralization titers suggests that relatively few residue changes in the E glycoprotein may have significant effects on DENV specific humoral immunity and influence antibody mediated protection or disease enhancement in the setting of both natural infection and vaccination. These genotypic differences are also likely to be important in temporal and spatial microevolution of DENV-3 in the background of heterotypic neutralization. The recombinant and synthetic tools
New Explicit Solutions of (1 + 1)-Dimensional Variable-Coefficient Broer-Kaup System
International Nuclear Information System (INIS)
Yan Zhilian; Zhou Jianping
2010-01-01
By using the compatibility method, many explicit solutions of the (1 + 1)-dimensional variable-coefficient Broer-Kaup system are constructed, which include new solutions expressed by error function, Bessel function, exponential function, and Airy function. Some figures of the solutions are given by the symbolic computation system Maple. (general)
Exact solutions for the (2+1)-dimensional Boiti-Leon-Pempielli system
International Nuclear Information System (INIS)
Hu, Y H; Zheng, C L
2008-01-01
The object reduction approach is applied to the (2+1)-dimensional Boiti-Leon-Pempielli system using a special conditional similarity reduction. Abundant exact solutions of this system, including the hyperboloid function solutions, the trigonometric function solutions and a rational function solution, are obtained
Greenberger-Horne-Zeilinger paradoxes for N N-dimensional systems
International Nuclear Information System (INIS)
Kaszlikowski, Dagomir; Zukowski, Marek
2002-01-01
We show the series of Greenberger-Horne-Zeilinger-like paradoxes for N maximally entangled N-dimensional quantum systems. The hypothesis of local hidden variables leads to a prediction of perfect correlations that do not appear for the quantum systems
Classification of all solutions of the algebraic Riccati equations for infinite-dimensional systems
Iftime, O; Curtain, R; Zwart, H
2003-01-01
We obtain a complete classification of all self-adjoint solution of the control algebraic Riccati equation for infinite-dimensional systems under the following assumptions: the system is output stabilizable, strongly detectable and the filter Riccati equation has an invertible self-adjoint
Directory of Open Access Journals (Sweden)
A. V. Krasnyuk
2008-03-01
Full Text Available Three-dimensional design possibilities of the AutoCAD system for performing graphic tasks are presented in the article. On the basis of the studies conducted the features of application of computer-aided design system are noted and the methods allowing to decrease considerably the quantity of errors at making the drawings are offered.
Segregation in quasi-two-dimensional granular systems
International Nuclear Information System (INIS)
Rivas, Nicolas; Cordero, Patricio; Soto, Rodrigo; Risso, Dino
2011-01-01
Segregation for two granular species is studied numerically in a vertically vibrated quasi-two-dimensional (quasi-2D) box. The height of the box is smaller than two particle diameters so that particles are limited to a submonolayer. Two cases are considered: grains that differ in their density but have equal size, and grains that have equal density but different diameters, while keeping the quasi-2D condition. It is observed that in both cases, for vibration frequencies beyond a certain threshold-which depends on the density or diameter ratios-segregation takes place in the lateral directions. In the quasi-2D geometry, gravity does not play a direct role in the in-plane dynamics and gravity does not point to the segregation directions; hence, several known segregation mechanisms that rely on gravity are discarded. The segregation we observe is dominated by a lack of equipartition between the two species; the light particles exert a larger pressure than the heavier ones, inducing the latter to form clusters. This energy difference in the horizontal direction is due to the existence of a fixed point characterized by vertical motion and hence vanishing horizontal energy. Heavier and bigger grains are more rapidly attracted to the fixed point and the perturbations are less efficient in taking them off the fixed point when compared to the lighter grains. As a consequence, heavier and bigger grains have less horizontal agitation than lighter ones. Although limited by finite size effects, the simulations suggest that the two cases we consider differ in the transition character: one is continuous and the other is discontinuous. In the cases where grains differ in mass on varying the control parameter, partial segregation is first observed, presenting many clusters of heavier particles. Eventually, a global cluster is formed with impurities; namely lighter particles are present inside. The transition looks continuous when characterized by several segregation order
Shilnikov sense chaos in a simple three-dimensional system
International Nuclear Information System (INIS)
Wei, Wang; Qi-Chang, Zhang; Rui-Lan, Tian
2010-01-01
The Shilnikov sense Smale horseshoe chaos in a simple 3D nonlinear system is studied. The proportional integral derivative (PID) controller is improved by introducing the quadratic and cubic nonlinearities into the governing equations. For the discussion of chaos, the bifurcate parameter value is selected in a reasonable regime at the requirement of the Shilnikov theorem. The analytic expression of the Shilnikov type homoclinic orbit is accomplished. It depends on the series form of the manifolds surrounding the saddle-focus equilibrium. Then the methodology is extended to research the dynamical behaviours of the simplified solar-wind-driven-magnetosphere-ionosphere system. As is illustrated, the Lyapunov characteristic exponent spectra of the two systems indicate the existence of chaotic attractor under some specific parameter conditions
Plasmons in Dimensionally Mismatched Coulomb Coupled Graphene Systems.
Badalyan, S M; Shylau, A A; Jauho, A P
2017-09-22
We calculate the plasmon dispersion relation for Coulomb coupled metallic armchair graphene nanoribbons and doped monolayer graphene. The crossing of the plasmon curves, which occurs for uncoupled 1D and 2D systems, is split by the interlayer Coulomb coupling into a lower and an upper plasmon branch. The upper branch exhibits an unusual behavior with end points at finite q. Accordingly, the structure factor shows either a single or a double peak behavior, depending on the plasmon wavelength. The new plasmon structure is relevant to recent experiments, its properties can be controlled by varying the system parameters and be used in plasmonic applications.
Hyperchaos and chaotic hierarchy in low-dimensional chemical systems
Baier, Gerold; Sahle, Sven
1994-06-01
Chemical reaction chains with feedback of one of the products on the source of the chain are considered. A strategy is presented in terms of ordinary differential equations which creates one, two, and three positive Lyapunov exponents as the finite dimension of the system is increased. In particular, a nonlinear inhibition loop in a chemical reaction sequence controls the type of chaos. The bifurcation scenarios are studied and chaos and hyperchaos are found for broad regions of bifurcation parameter. Some implications for the occurrence of higher chaos in real systems are discussed.
Three-dimensional television system for remote handling
International Nuclear Information System (INIS)
Dumbreck, A.A.; Abel, E.
1988-01-01
The paper refers to work previously described on the development of 3-D Television Systems. 3-D TV had been developed with a view to proving whether it was a useful remote handling tool which would be easy to use and comfortable to view. The paper summarizes the work of evaluation trials at UK facilities and reviews the developments which have subsequently taken place. 3-D TV systems have been found to give improved performance in terms of speed and accuracy of operations and to reduce the number of camera views required. (author)
One dimensional Dirac-Moshinsky oscillator-like system and isospectral partners
International Nuclear Information System (INIS)
Contreras-Astorga, A
2015-01-01
Two different exactly solvable systems are constructed using the supersymmetric quantum mechanics formalism and a pseudoscalar one-dimensional version of the Dirac- Moshinsky oscillator as a departing system. One system is built using a first-order SUSY transformation. The second is obtained through the confluent supersymmetry algorithm. The two of them are explicitly designed to have the same spectrum as the departing system and pseudoscalar potentials. (paper)
A measurement system for two-dimensional DC-biased properties of magnetic materials
International Nuclear Information System (INIS)
Enokizono, M.; Matsuo, H.
2003-01-01
So far, the DC-biased magnetic properties have been measured in one dimension (scalar). However, these scalar magnetic properties are not enough to clarify the DC-biased magnetic properties because the scalar magnetic properties cannot exactly take into account the phase difference between the magnetic flux density B vector and the magnetic filed strength H vector. Thus, the magnetic field strength H and magnetic flux density B in magnetic materials must be measured as vector quantities (two-dimensional), directly. We showed the measurement system using a single-sheet tester (SST) to clarify the two-dimensional DC-biased magnetic properties. This system excited AC in Y-direction and DC in X-direction. This paper shows the measurement system using an SST and presents the measurement results of two-dimensional DC-biased magnetic properties when changing the DC exciting voltage and the iron loss
Linear stability theory as an early warning sign for transitions in high dimensional complex systems
International Nuclear Information System (INIS)
Piovani, Duccio; Grujić, Jelena; Jensen, Henrik Jeldtoft
2016-01-01
We analyse in detail a new approach to the monitoring and forecasting of the onset of transitions in high dimensional complex systems by application to the Tangled Nature model of evolutionary ecology and high dimensional replicator systems with a stochastic element. A high dimensional stability matrix is derived in the mean field approximation to the stochastic dynamics. This allows us to determine the stability spectrum about the observed quasi-stable configurations. From overlap of the instantaneous configuration vector of the full stochastic system with the eigenvectors of the unstable directions of the deterministic mean field approximation, we are able to construct a good early-warning indicator of the transitions occurring intermittently. (paper)
Phases, phase equilibria, and phase rules in low-dimensional systems
International Nuclear Information System (INIS)
Frolov, T.; Mishin, Y.
2015-01-01
We present a unified approach to thermodynamic description of one, two, and three dimensional phases and phase transformations among them. The approach is based on a rigorous definition of a phase applicable to thermodynamic systems of any dimensionality. Within this approach, the same thermodynamic formalism can be applied for the description of phase transformations in bulk systems, interfaces, and line defects separating interface phases. For both lines and interfaces, we rigorously derive an adsorption equation, the phase coexistence equations, and other thermodynamic relations expressed in terms of generalized line and interface excess quantities. As a generalization of the Gibbs phase rule for bulk phases, we derive phase rules for lines and interfaces and predict the maximum number of phases than may coexist in systems of the respective dimensionality
K-intercalated carbon systems: Effects of dimensionality and substrate
Kaloni, Thaneshwor P.; Kahaly, M. Upadhyay; Cheng, Yingchun; Schwingenschlö gl, Udo
2012-01-01
the charge carrier density. Reasonably high values are found for all systems, the highest carrier density for the bilayer. The band structure and electron-phonon coupling of free-standing K-intercalated bilayer graphene points to a high probability