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Sample records for accelerator driven systems

  1. Accelerating Science Driven System Design With RAMP

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynek, John [Univ. of California, Berkeley, CA (United States)

    2015-05-01

    Researchers from UC Berkeley, in collaboration with the Lawrence Berkeley National Lab, are engaged in developing an Infrastructure for Synthesis with Integrated Simulation (ISIS). The ISIS Project was a cooperative effort for “application-driven hardware design” that engages application scientists in the early parts of the hardware design process for future generation supercomputing systems. This project served to foster development of computing systems that are better tuned to the application requirements of demanding scientific applications and result in more cost-effective and efficient HPC system designs. In order to overcome long conventional design-cycle times, we leveraged reconfigurable devices to aid in the design of high-efficiency systems, including conventional multi- and many-core systems. The resulting system emulation/prototyping environment, in conjunction with the appropriate intermediate abstractions, provided both a convenient user programming experience and retained flexibility, and thus efficiency, of a reconfigurable platform. We initially targeted the Berkeley RAMP system (Research Accelerator for Multiple Processors) as that hardware emulation environment to facilitate and ultimately accelerate the iterative process of science-driven system design. Our goal was to develop and demonstrate a design methodology for domain-optimized computer system architectures. The tangible outcome is a methodology and tools for rapid prototyping and design-space exploration, leading to highly optimized and efficient HPC systems.

  2. Small type accelerator. Try for accelerator driven system

    CERN Document Server

    Mori, Y

    2003-01-01

    FFAG (Fixed-field alternating gradient) accelerator for accelerator driven subcritical reactor, which aims to change from long-lived radioactive waste to short-lived radioactivity, is introduced. It is ring accelerator. The performance needed is proton as accelerator particle, 10MW (total) beam power, about 1GeV beam energy, >30% power efficiency and continuous beam. The feature of FFAG accelerator is constant magnetic field. PoP (Proof-of-principle)-FFAG accelerator, radial type, was run at first in Japan in 2000. The excursion is about some ten cm. In principle, beam can be injected and extracted at any place of ring. The 'multi-fish' acceleration can accelerate beams to 100% duty by repeating acceleration. 150MeV-FFAG accelerator has been started since 2001. It tried to practical use, for example, treatment of cancer. (S.Y.)

  3. Microwave ion source for accelerator driven sub-critical system

    CERN Document Server

    Cui Bao Qun; Jiang Wei; LiLiQiang; WangRongWen

    2002-01-01

    A microwave ion source is under developing for a demonstration prototype of a accelerator driven sub-critical system at CIAE (China Institute of Atomic Energy), 100 mA hydrogen beam has been extracted from the source through a 7.3 mm aperture in diameter, proton ratio is more than 85%, reliability has been tested for 100 h without any failures

  4. Accelerator driven systems from the radiological safety point of view

    Indian Academy of Sciences (India)

    Abstract. In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead– bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community.

  5. Reactivity Monitoring of Accelerator-Driven Nuclear Reactor Systems

    NARCIS (Netherlands)

    Uyttenhove, W.

    2016-01-01

    This thesis provides a methodology and set-up of a reactivity monitoring tool for Accelerator-Driven Systems (ADS). The reactivity monitoring tool should guarantee the operation of an ADS at a safe margin from criticality. Robustness is assured in different aspects of the monitoring tool: the choice

  6. Accelerator driven systems from the radiological safety point of view

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead–bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community.

  7. System and safety studies of accelerator driven transmutation systems

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2001-05-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the department has been focused on: a) ADS core design and development of advanced nuclear fuel optimised for high transmutation rates and good safety features; b) analysis of ADS-dynamics c) computer code and nuclear data development relevant for simulation and optimization of ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE (CEA-Cadarache). Moreover, during the reporting period the EU-project 'IABAT', co-ordinated by the department has been finished and 4 other projects have been initiated in the frame of the 5th European Framework Programme. Most of the research topics reported in this paper are referred to appendices, which have been published in the open literature. The topics, which are not yet published, are described here in more details.

  8. Role of accelerator-driven systems in waste incineration scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Salvatores, M.; Slessarev, I.; Tchistiakov, A. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Direction des Reacteurs Nucleaires; Spiro, M.; Terrien, Y.; Mouney, H.; Vergnes, J.

    1997-12-31

    At CEA accelerator-driven systems (ADS) are studied in the frame of the R and D required to answer the request of a law voted in 1991 by the French Parliament, `to search for solutions allowing to partition and transmute long lived radioactive wastes, in order to reduce their volume and toxicity`. These systems (called `INCAs`) are still at a conceptual level. However, the role of ADS has been clarified as a first step, and this will be the subject of the present paper. (author)

  9. Accelerated Tests of Soft Errors in Network Systems Using a Compact Accelerator- Driven Neutron Source

    Science.gov (United States)

    Iwashita, Hidenori; Sato, Hirotaka; Arai, Kaoru; Kotanigawa, Takashi; Kino, Koichi; Kamiyama, Takashi; Hiraga, Fujio; Koda, Katsutoshi; Furusaka, Michihiro; Kiyanagi, Yoshiaki

    2017-01-01

    The frequency of neutron-induced soft errors is increasing as devices become more integrated and miniaturized. Therefore, it has become more important recently to check reliability of a recovery system from the soft errors in network systems. For accelerated test, first we have examined possibility of the acceleration tests at a compact accelerator-driven neutron source, which is easy to adjust for soft-error tests and which also has low experimental costs. We selected the electron accelerator-driven neutron source at Hokkaido University as the compact accelerator-driven neutron source. We prepared a new target-reflector assembly composed of heavy metals to provide the fast neutrons, and conducted neutron-induced soft-error experiments on network equipments. As a result, we found that an accelerated rate of soft errors was about 106 times compared with that of the natural environment. We also investigated network equipment soft-error tolerance, fault detection and backup switching processes. Performing such testing before network equipment is actually deployed is critical for development of future network systems. Hence, the compact accelerator-based neutron source is a very useful tool.

  10. Thorium as a Fuel for Accelerator Driven Subcritical Electronuclear Systems

    CERN Document Server

    Barashenkov, V S; Singh, V

    2000-01-01

    Neutron yield and energy production in a very large, practically infinite, uranium and thorium target-blocks irradiated by protons with energies in the range 0.1-2 GeV are studied by Monte Carlo method. Though the comparison of uranium and thorium targets shows that the neutron yield in the latter is 30-40 % less and the energy gain is approximatelly two times smaller, accelerator Driven subcritical Systems (ADS) with thorium fuel are very perspective at the bombarding energies higher than several hundreds MeV. An admixture of fissile elements U^{233}, U^{235}, Pu^{239} in the set-up gives larger neutron multiplication which in turn shows better energy amplification. It is argued that due to the practically complete burning of the fuel in such set-up there is no need of technology of conversion of the exhaust fuel.

  11. Concept of an Accelerator-Driven Advanced Nuclear Energy System

    Directory of Open Access Journals (Sweden)

    Xuesong Yan

    2017-07-01

    Full Text Available The utilization of clean energy is a matter of primary importance for sustainable development as well as a vital approach for solving worldwide energy-related issues. If the low utilization rate of nuclear fuel, nuclear proliferation, and insufficient nuclear safety can be solved, nuclear fission energy could be used as a sustainable and low-carbon clean energy form for thousands of years, providing steady and base-load electrical resources. To address these challenges, we propose an accelerator-driven advanced nuclear energy system (ADANES, consisting of a burner system and a fuel recycle system. In ADANES, the ideal utilization rate of nuclear fuel will be >95%, and the final disposal of nuclear waste will be minimized. The design of a high-temperature ceramic reactor makes the burner system safer. Part of fission products (FPs are removed during the simple reprocessing in the fuel recycle system, significantly reducing the risks of nuclear proliferation of nuclear technology and materials. The ADANES concept integrates nuclear waste transmutation, nuclear fuel breeding, and safety power production, with an ideal closed loop operation of nuclear fission energy, constituting a major innovation of great potential interest for future energy applications.

  12. Transmutation of nuclear waste in accelerator-driven systems

    CERN Document Server

    Herrera-Martínez, A

    2004-01-01

    Today more than ever energy is not only a cornerstone of human development, but also a key to the environmental sustainability of economic activity. In this context, the role of nuclear power may be emphasized in the years to come. Nevertheless, the problems of nuclear waste, safety and proliferation still remain to be solved. It is believed that the use of accelerator-driven systems (ADSs) for nuclear waste transmutation and energy production would address these problems in a simple, clean and economically viable, and therefore sustainable, manner. This thesis covers the major nuclear physics aspects of ADSs, in particular the spallation process and the core neutronics specific to this type of systems. The need for accurate nuclear data is described, together with a detailed analysis of the specific isotopes and energy ranges in which this data needs to be improved and the impact of their uncertainty. Preliminary experimental results for some of these isotopes, produced by the Neutron Time-of-Flight (n_TOF) ...

  13. Operational Characteristics of an Accelerator Driven Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-28

    Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the form of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems requires the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a “generic” Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system

  14. Thermal hydraulics of accelerator driven system windowless targets

    Directory of Open Access Journals (Sweden)

    Bruno ePanella

    2015-07-01

    Full Text Available The study of the fluid dynamics of the windowless spallation target of an Accelerator Driven System (ADS is presented. Several target mockup configurations have been investigated: the first one was a symmetrical target, that was made by two concentric cylinders, the other configurations are not symmetrical. In the experiments water has been used as hydraulic equivalent to lead-bismuth eutectic fluid. The experiments have been carried out at room temperature and flow rate up to 24 kg/s. The fluid velocity components have been measured by an ultrasound technique. The velocity field of the liquid within the target region either for the approximately axial-symmetrical configuration or for the not symmetrical ones as a function of the flow rate and the initial liquid level is presented. A comparison of experimental data with the prediction of the finite volume FLUENT code is also presented. Moreover the results of a 2D-3D numerical analysis that investigates the effect on the steady state thermal and flow fields due to the insertion of guide vanes in the windowless target unit of the EFIT project ADS nuclear reactor are presented, by analysing both the cold flow case (absence of power generation and the hot flow case (nominal power generation inside the target unit.

  15. Physics design of an accelerator for an accelerator-driven subcritical system

    Directory of Open Access Journals (Sweden)

    Zhihui Li

    2013-08-01

    Full Text Available An accelerator-driven subcritical system (ADS program was launched in China in 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in multiple phases lasting about 20 years. The driver linac is defined to be 1.5 GeV in energy, 10 mA in current and in cw operation mode. To meet the extremely high reliability and availability, the linac is designed with much installed margin and fault tolerance, including hot-spare injectors and local compensation method for key element failures. The accelerator complex consists of two parallel 10-MeV injectors, a joint medium-energy beam transport line, a main linac, and a high-energy beam transport line. The superconducting acceleration structures are employed except for the radio frequency quadrupole accelerators (RFQs which are at room temperature. The general design considerations and the beam dynamics design of the driver linac complex are presented here.

  16. Thermal-hydraulics of lead bismuth for accelerator driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Schulenberg; Xu Cheng; Robert Stieglitz [Institute for Nuclear and Energy Technologies, Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany)

    2005-07-01

    Full text of publication follows: Lead bismuth has been selected as one of the most suitable coolants to be used in accelerator driven systems (ADS) for transmutation of minor actinides. It serves both, as a target material of the spallation source to balance the neutron economy, and as a coolant with high thermal inertia to provide a safe and reliable heat transfer to the secondary power cycle. With the aim to develop the required technologies to enable the later design of such ADS systems, the Karlsruhe Lead bismuth LAboratory KALLA, consisting of three test loops, has been built and set into operation at the Forschungszentrum Karlsruhe since 2000, keeping more than 45 t of PbBi in operation at temperatures up to 550 deg. C. The test program includes oxygen control systems, heat flux simulation tools, electro-magnetic and mechanical pump technologies, heat transfer and flow measurements, reliability and corrosion tests. In a first test campaign, a technology loop called THESYS was built to develop measurement technologies for the acquisition of scalar quantities, like pressures, temperatures, concentrations, and flow rates, as well as velocity fields, which are required for both operational and scientific purposes. THESYS also allowed to perform generic turbulent heat transfer experiments necessary to provide liquid metal adapted turbulent heat transfer models for ADS design analyses. The second loop, the thermalhydraulic loop THEADES with an installed power of 2.5 MW, has been built to conduct prototypical component experiments for beam windows (e.g. MEGAPIE or MYHRRA) or fuel rod configurations. First test results will be reported. The experimental team is supported by a numerical team who studied the thermal hydraulics of the tested components in order to enable a later transfer of the results to industrial systems. Three different types of codes are being improved: lumped parameter codes (e.g. ATHLET) to perform system analyses for lead bismuth in loops

  17. Disposition of nuclear waste using subcritical accelerator-driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Venneri, F.; Li, N.; Williamson, M.; Houts, M.; Lawrence, G.

    1998-12-31

    Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.

  18. Study on design of superconducting proton linac for accelerator driven subcritical nuclear power system

    CERN Document Server

    Yu Qi; Xu Tao Guang

    2002-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac (SCL) is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. It is constitute by a series of the superconducting accelerating cavities. The cavity geometry is determined by means of the electromagnetic field computation. The SCL main parameters are determined by the particle dynamics computation

  19. Opportunity of characteristic's improvement for accelerator driven systems

    CERN Document Server

    Kiselev, G V

    2001-01-01

    Review of sentences on the investigation into different variations of electronuclear plants be directed to the improvement in characteristics of the plants in an effort to the efficient disposal of long-lived components of radioactive wastes is presented. Attention is drown to the fact that subcritical reactor with complicated neutron valve can be used. This permits for drop in demand to current of proton accelerator. Briefly description of the process scheme with the indication of problems is given

  20. Monte Carlo Analysis of the Accelerator-Driven System at Kyoto University Research Reactor Institute

    Directory of Open Access Journals (Sweden)

    Wonkyeong Kim

    2016-04-01

    Full Text Available An accelerator-driven system consists of a subcritical reactor and a controllable external neutron source. The reactor in an accelerator-driven system can sustain fission reactions in a subcritical state using an external neutron source, which is an intrinsic safety feature of the system. The system can provide efficient transmutations of nuclear wastes such as minor actinides and long-lived fission products and generate electricity. Recently at Kyoto University Research Reactor Institute (KURRI; Kyoto, Japan, a series of reactor physics experiments was conducted with the Kyoto University Critical Assembly and a Cockcroft–Walton type accelerator, which generates the external neutron source by deuterium–tritium reactions. In this paper, neutronic analyses of a series of experiments have been re-estimated by using the latest Monte Carlo code and nuclear data libraries. This feasibility study is presented through the comparison of Monte Carlo simulation results with measurements.

  1. The GUINEVERE project for Accelerator Driven System physics

    Energy Technology Data Exchange (ETDEWEB)

    Billebaud, A.; Baylac, M.; Bondoux, D.; Bouvier, J.; Chabod, S.; De Conto, J.M.; Nuttin, A. [LPSC-CNRS-IN2P3/UJF/INPG, 53 Avenue des Martyrs. 38026 Grenoble cedex (France); Baeten, P.; Ait Abderrahim, H.; Bergmans, G.; Chetnitkov, A.; Kochetkov, A.; Vandeplassche, D.; Vermeersch, F.; Vittiglio, G. [SCK.CEN, Boeretang 200, 2400 Mol (Belgium); Ban, G.; Gautier, J.M.; Lecolley, F.R.; Lecouey, J.L.; Marie, N.; Merrer, Y.; Steckmeyer, J.C. [LPC Caen, ENSICAEN/Universite de Caen/CNRS-IN2P3, 14050 Caen (France); Dessagne, P.; Gaudiot, G.; Heitz, G.; Kerveno, M. [IPHC-DRS/UdS/CNRS-IN2P3, 67037 Strasbourg (France); Granget, G.; Mellier, F. [CEA-Cadarache, 13108 Saint Paul-lez-Durance (France); Laune, B.; Reynet, D. [IPNO, CNRS-IN2P3/UPS, 91406 Orsay (France)

    2009-06-15

    The GUINEVERE project is part of the EUROTRANS Integrated Project of the 6. EURATOM Framework Programme. It is mainly devoted to ADS on-line reactivity monitoring validation, subcriticality determination and operational procedures (loading, start-up, shut-down,..) in follow-up of the MUSE experiments. The project consists in coupling a fast lead core, set-up in the VENUS reactor at SCK.CEN Mol (B), with a GENEPI neutron source under construction by CNRS. To accommodate the accelerator in a vertical coupling configuration, the VENUS building is being heightened. The fast core will be loaded with enriched Uranium and will be moderated and reflected with solid lead (zero power experiment). For the purpose of the experimental programme, the neutron source has to be operated not only in pulsed mode but also in continuous mode to investigate the current-to-flux reactivity indicator in representative conditions of a powerful ADS. In this latter mode it is also required to make short beam interruptions to have access to the neutron population decrease as a function of time: from this spectrum it will be possible to apply different analysis techniques such as 'prompt decay' fitting techniques and 'source jerk' techniques. Beam interruptions will be repeated at a programmable frequency to improve time spectra statistics. Different sub-criticality levels (k{sub eff}=0.99, 0.97, 0.95,..) will be investigated in order to obtain a full set of data points for the final overall validation of the methodology. This paper describes the status of the experimental facility assembling, and the foreseen experimental programme to be started. (authors)

  2. Simulator for an Accelerator-Driven Subcritical Fissile Solution System

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Day, Christy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Determan, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-14

    LANL has developed a process to generate a progressive family of system models for a fissile solution system. This family includes a dynamic system simulation comprised of coupled nonlinear differential equations describing the time evolution of the system. Neutron kinetics, radiolytic gas generation and transport, and core thermal hydraulics are included in the DSS. Extensions to explicit operation of cooling loops and radiolytic gas handling are embedded in these systems as is a stability model. The DSS may then be converted to an implementation in Visual Studio to provide a design team the ability to rapidly estimate system performance impacts from a variety of design decisions. This provides a method to assist in optimization of the system design. Once design has been generated in some detail the C++ version of the system model may then be implemented in a LabVIEW user interface to evaluate operator controls and instrumentation and operator recognition and response to off-normal events. Taken as a set of system models the DSS, Visual Studio, and LabVIEW progression provides a comprehensive set of design support tools.

  3. Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system

    CERN Document Server

    Yu Qi; Ouyang Hua Fu; Xu Tao Guang

    2001-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered

  4. System and safety studies of accelerator driven systems for transmutation. Annual report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Arzhanov, Vasily; Fokau, Andrei; Persson, Calle; Runevall, Odd; Sandberg, Nils; Tesinsky, Milan; Wallenius, Janne; Youpeng Zhang (Div. of Reactor Physics, Royal Institute of Technology, Stockholm (Sweden))

    2008-05-15

    Within the project 'System and safety studies of accelerator driven systems for transmutation', research on design and safety of sub-critical reactors for recycling of minor actinides is performed. During 2007, the reactor physics division at KTH has calculated safety parameters for EFIT-400 with cermet fuel, permitting to start the transient safety analysis. The accuracy of different reactivity meters applied to the YALINA facility was assessed and neutron detection studies were performed. A model to address deviations from point kinetic behaviour was developed. Studies of basic radiation damage physics included calculations of vacancy formation and activation enthalpies in bcc niobium. In order to predict the oxygen potential of inert matrix fuels, a thermo-chemical model for mixed actinide oxides was implemented in a phase equilibrium code

  5. PW-class laser-driven super acceleration systems in underdense plasmas

    Science.gov (United States)

    Yano, Masahiro; Zhidkov, Alexei; Kodama, Ryosuke

    2017-10-01

    Probing laser driven super-acceleration systems can be important tool to understand physics related to vacuum, space time, and particle acceleration. We show two proposals to probe the systems through Hawking-like effect using PW class lasers and x-ray free electron lasers. For that we study the interaction of ultrahigh intense laser pulses with intensity 1022 -1024 W/cm2 and underdense plasmas including ion motion and plasma radiation for the first time. While the acceleration w a0ωp /ωL in a wake is not maximal, the pulse propagation is much stable. The effect is that a constantly accelerated detector with acceleration w sees a boson's thermal bath at temperature ℏw / 2 πkB c . We present two designs for x-ray scattering from highly accelerated electrons produced in the plasma irradiated by intense laser pulses for such detection. Properly chosen observation angles enable us to distinguish spectral broadening from Doppler shift with a reasonable photon number. Also, ion motion and radiation damping on the interaction are investigated via fully relativistic 3D particle-in-cell simulation. We observe high quality electron bunches under super-acceleration when transverse plasma waves are excited by ponderomotive force producing plasma channel.

  6. Numerical simulations of flow field in the target region of accelerator-driven subcritical reactor system

    CERN Document Server

    Chen Hai Yan

    2002-01-01

    Numerical simulations of flow field were performed by using the PHOENICS 3.2 code for the proposed spallation target of accelerator-driven subcritical reactor system (ADS). The fluid motion in the target is axisymmetric and is treated as a 2-D steady-state problem. A body-fitted coordinate system (BFC) is then chosen and a two-dimensional mesh of the flow channel is generated. Results are presented for the ADS target under both upward and downward flow, and for the target with diffuser plate installed below the window under downward flow

  7. Investigation of Lead Target Nuclei Used on Accelerator-Driven Systems for Tritium Production

    Science.gov (United States)

    Tel, E.; Aydin, A.

    2012-02-01

    High-current proton accelerators are being researched at Los Alamos National Laboratory and other laboratories for accelerator production of tritium, transmuting long-lived radioactive waste into shorter-lived products, converting excess plutonium, and producing energy. These technologies make use of spallation neutrons produced in ( p,xn) and ( n,xn) nuclear reactions on high-Z targets. Through ( p,xn) and ( n,xn) nuclear reactions, neutrons are produced and are moderated by heavy water. These moderated neutrons are subsequently captured on 3He to produce tritium via the ( n,p) reaction. Tritium self-sufficiency must be maintained for a commercial fusion power plant. Rubbia succeeded in a proposal of a full scale demonstration plant of the Energy Amplifier. This plant is to be known the accelerator-driven system (ADS). The ADS can be used for production of neutrons in spallation neutron source and they can act as an intense neutron source in accelerator-driven subcritical reactors, capable of incinerating nuclear waste and of producing energy. Thorium and Uranium are nuclear fuels and Lead, Bismuth, Tungsten are the target nuclei in these reactor systems. The spallation targets can be Pb, Bi, W, etc. isotopes and these target material can be liquid or solid. Naturally Lead includes the 204Pb (%1.42), 206Pb (%24.1), 207Pb (%22.1) and 208Pb (%52.3) isotopes. The design of ADS systems and also a fusion-fission hybrid reactor systems require the knowledge of a wide range of better data. In this study, by using Hartree-Fock method with an effective nucleon-nucleon Skyrme interactions rms nuclear charge radii, rms nuclear mass radii, rms nuclear proton, neutron radii and neutron skin thickness were calculated for the 204, 206, 208Pb isotopes . The calculated results have been compared with those of the compiled experimental and theoretical values of other studies.

  8. MYRRHA project: a Multipurpose Accelerator Driven System (ADS) for R and D

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The objective of the MYRRHA project is to develop a multipurpose neutron source for research and development applications on the basis of an Accelerator Driven System (ADS). Current activities in this area focus on (1) the continuation and the extension towards ADS of the ongoing programmes at SCK-CEN in the field of reactor materials, fuel and reactor physics research; (2) the enhancement and the triggering of new R and D activities such as nuclear waste transmutation, ADS technology, liquid metal embrittlement; (3) the initiation of medical applications, for example proton therapy and PET production, or proton Based irradiation programmes. Main achievements in these topical areas in 2000 are summarised.

  9. Neutronic studies in support of accelerator-driven systems: The MUSE experiments in the MASURCA facility

    OpenAIRE

    Soule, R.; Assal, W.; Chaussonnet, P.; Destouches, C.; Domergue, C.; Jammes, C.; Laurens, J.-M.; Lebrat, J.-F.; Mellier, F.; Perret, G.; Rimpault, G.; Servière, H.; Imel, G.; M. Thomas, G.; Villamarin, D.

    2004-01-01

    The MUSE program (multiplication with an external source) is in progress at the MASURCA critical facility at the Cadarache Research Center of the Commissariat à l'Energie Atomique in France. The program is dedicated to the physics studies of accelerator-driven systems in support of transmutation studies of minor actinides and long-lived fission products. It began in 1995 with the coupling of a Cf source in MASURCA and was followed by a commercial (d,T) source. In 2001, a specially constructed...

  10. Compact beam transport system for free-electron lasers driven by a laser plasma accelerator

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-02-01

    Full Text Available Utilizing laser-driven plasma accelerators (LPAs as a high-quality electron beam source is a promising approach to significantly downsize the x-ray free-electron laser (XFEL facility. A multi-GeV LPA beam can be generated in several-centimeter acceleration distance, with a high peak current and a low transverse emittance, which will considerably benefit a compact FEL design. However, the large initial angular divergence and energy spread make it challenging to transport the beam and realize FEL radiation. In this paper, a novel design of beam transport system is proposed to maintain the superior features of the LPA beam and a transverse gradient undulator (TGU is also adopted as an effective energy spread compensator to generate high-brilliance FEL radiation. Theoretical analysis and numerical simulations are presented based on a demonstration experiment with an electron energy of 380 MeV and a radiation wavelength of 30 nm.

  11. Application of gas-cooled Accelerator Driven System (ADS) transmutation devices to sustainable nuclear energy development

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, A., E-mail: abanades@etsii.upm.es [ETSII/Universidad Politecnica de Madrid, J.Gutierrez Abascal, 2-28006 Madrid (Spain); Garcia, C.; Garcia, L. [Instituto Superior de Tecnologia y Ciencias Aplicadas. Quinta de los, Molinos, Ave. Salvador Allende y Luaces, Ciudad de la Habana, CP 10400, Apartado Postal 6163 (Cuba); Escriva, A.; Perez-Navarro, A. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, C.P. 46022 Valencia (Spain); Rosales, J. [Instituto Superior de Tecnologia y Ciencias Aplicadas. Quinta de los, Molinos, Ave. Salvador Allende y Luaces, Ciudad de la Habana, CP 10400, Apartado Postal 6163 (Cuba)

    2011-06-15

    Highlights: > Utilization of Accelerator Driven System (ADS) for Hydrogen production. > Evaluation of the potential use of gas-cooled ADS for a sustainable use of Uranium resources by transmutation of nuclear wastes, electricity and Hydrogen production. > Application of the Sulfur-Iodine thermochemical process to subcritical systems. > Application of CINDER90 to calculate burn-up in subcritical systems. - Abstract: The conceptual design of a pebble bed gas-cooled transmutation device is shown with the aim to evaluate its potential for its deployment in the context of the sustainable nuclear energy development, which considers high temperature reactors for their operation in cogeneration mode, producing electricity, heat and Hydrogen. As differential characteristics our device operates in subcritical mode, driven by a neutron source activated by an accelerator that adds clear safety advantages and fuel flexibility opening the possibility to reduce the nuclear stockpile producing energy from actual LWR irradiated fuel with an efficiency of 45-46%, either in the form of Hydrogen, electricity, or both.

  12. Application of variance reduction technique to nuclear transmutation system driven by accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In Japan, it is the basic policy to dispose the high level radioactive waste arising from spent nuclear fuel in stable deep strata after glass solidification. If the useful elements in the waste can be separated and utilized, resources are effectively used, and it can be expected to guarantee high economical efficiency and safety in the disposal in strata. Japan Atomic Energy Research Institute proposed the hybrid type transmutation system, in which high intensity proton accelerator and subcritical fast core are combined, or the nuclear reactor which is optimized for the exclusive use for transmutation. The tungsten target, minor actinide nitride fuel transmutation system and the melted minor actinide chloride salt target fuel transmutation system are outlined. The conceptual figures of both systems are shown. As the method of analysis, Version 2.70 of Lahet Code System which was developed by Los Alamos National Laboratory in USA was adopted. In case of carrying out the analysis of accelerator-driven subcritical core in the energy range below 20 MeV, variance reduction technique must be applied. (K.I.)

  13. Monte-Carlo Simulation of the Features of Bi-Reactior Accelerator Driven Systems

    CERN Document Server

    Bznuni, S A; Khudaverdian, A G; Barashenkov, V S; Sosnin, A N; Polyanskii, A A

    2002-01-01

    Parameters of accelerator-driven systems containing two "cascade" subcritical assemblies (liquid metal fast reactor, used as a neutron booster, and a thermal reactor, where main heat production is taking place) are investigated. Three main reactor cores analogous to VVER-1000, MSBR-1000 and CANDU-6 reactors are considered. Functioning in a safe mode (k_{eff}=0.94-0.98) these systems under consideration demonstrate much larger capacity in the wide range of k_{eff} in comparison with analogous systems without intermediate fast booster reactor and simultaneously having the density of thermal neutron flux equal to Phi^{max}=10^{14} cm^{-2}c^{-1} and operating with the fast and thermal zones they are capable to transmute the whole scope of nuclear waste reducing the requirements on the beam current of the accelerator by one order of magnitude. It seems to be the most important in case when molten salt thermal breeder reactor cores are considered as a main heat generating zone.

  14. System and safety studies of accelerator driven transmutation. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J.; Chakarova, R.; Westlen, D. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2002-03-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the Dept. of Nuclear and Reactor Physics has been focused in year 2001 on: a) ADS core design and development of advanced nuclear fuel optimised for high transmutation rates and good safety features; b) analysis of ADS-dynamics; c) computer code and nuclear data development relevant for simulation and optimization of ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE (CEA-Cadarache) and YALINA experiment in Minsk. The Dept. is very actively participating in many European projects in the 5th Framework Programme of the European Community. Most of the research topics reported in this paper are referred to by appendices, which have been published in the open literature. The topics, which are not yet published, are described here in more details.

  15. MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Habob, Moinul

    2005-12-15

    In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design.

  16. System and safety studies of accelerator driven transmutation. Annual Report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, Waclaw; Wallenius, Jan; Tucek, Kamil [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics] [and others

    2004-12-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the Dept. of Nuclear and Reactor Physics reported here has been focused on different aspects of safety of the Accelerator-Driven Transmutation Systems and on Transmutation research in more general terms. An overview of the topics of our research is given in the Summary which is followed by detailed reports as separate chapters or subchapters. Some of the research topics reported in this report are referred to appendices, which have been published in the open literature. Topics, which are not yet published, are described with more details in the main part of this report. Main focus has been, as before, largely determined by the programme of the European projects of the 5th Framework Programme in which KTH is actively participating. In particular: a) ADS core design and development of advanced nuclear fuel optimised for high transmutation rates and good safety features. This activity includes even computer modeling of nuclear fuel production. Three different ADS-core concept are being investigated: Conceptual design of Pb-Bi cooled core with nitride fuel so called Sing-Sing Core developed at KTH; Pb-Bi cooled core with oxide fuel so called ANSALDO design for the European Project PDS-XADS; Gas cooled core with oxide fuel a design investigated for the European Project PDS-XADS. b) analysis of potential of advance fuels, in particular nitrides with high content of minor actinides; c) analysis of ADS-dynamics and assessment of major reactivity feedbacks; d) emergency heat removal from ADS; e) participation in ADS: MUSE (CEA-Cadarache), YALINA subcritical experiment in Minsk and designing of the subcritical experiment SAD in Dubna; f) theoretical and simulation studies of radiation damage in high neutron (and/or proton) fluxes; g) computer code and nuclear data development relevant for simulation and optimization of ADS, validation of the MCB code and sensitivity analysis; h) studies of

  17. System and safety studies of accelerator driven transmutation Annual Report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, Waclaw; Wallenius, Jan; Arzhanov, Vasily; Jolkkonen, Mikael; Eriksson, Marcus; Seltborg, Per; Westlen, Daniel; Lagerstedt, Christina; Isaksson, Patrick; Persson, Carl-Magnus; Aalander, Alexandra [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2006-11-15

    The results of the research activities on System and Safety of Accelerator-Driven Transmutation (ADS) at the Department of Nuclear and Reactor Physics are described in this report followed by the Appendices of the relevant scientific papers published in 2005. PhD and Licentiate dissertations of Marcus Ericsson, Per Seltborg, Christina Lagerstedt and Daniel Westlen (see Appendices) reflect the research mainstream of 2005. Year 2005 was also very rich in international activities with ADS in focus. Summary of conferences, seminars and lecturing activities is given in Chapter 9 Research activities of 2005 have been focused on several areas: system and safety studies of ADS; subcritical experiments; ADS source efficiency studies; nuclear fuel cycle analysis; potential of reactor based transmutation; ADS fuel development; simulation of radiation damage; and development of codes and methods. Large part of the research activities has been well integrated with the European projects of the 5th and 6th Framework Programmes of the European Commission in which KTH is actively participating. In particular European projects: RED-IMPACT, CONFIRM, FUTURE, EUROTRANS and NURESIM.

  18. Hydrogen production methods efficiency coupled to an advanced high temperature accelerator driven system

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Daniel González; Lira, Carlos Alberto Brayner de Oliveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Fernández, Carlos García, E-mail: danielgonro@gmail.com, E-mail: mmhamada@ipen.br [Instituto Superior de Tecnologías y Ciencias aplicadas (InSTEC), La Habana (Cuba)

    2017-07-01

    The hydrogen economy is one of the most promising concepts for the energy future. In this scenario, oil is replaced by hydrogen as an energy carrier. This hydrogen, rather than oil, must be produced in volumes not provided by the currently employed methods. In this work two high temperature hydrogen production methods coupled to an advanced nuclear system are presented. A new design of a pebbled-bed accelerator nuclear driven system called TADSEA is chosen because of the advantages it has in matters of transmutation and safety. For the conceptual design of the high temperature electrolysis process a detailed computational fluid dynamics model was developed to analyze the solid oxide electrolytic cell that has a huge influence on the process efficiency. A detailed flowsheet of the high temperature electrolysis process coupled to TADSEA through a Brayton gas cycle was developed using chemical process simulation software: Aspen HYSYS®. The model with optimized operating conditions produces 0.1627 kg/s of hydrogen, resulting in an overall process efficiency of 34.51%, a value in the range of results reported by other authors. A conceptual design of the iodine-sulfur thermochemical water splitting cycle was also developed. The overall efficiency of the process was calculated performing an energy balance resulting in 22.56%. The values of efficiency, hydrogen production rate and energy consumption of the proposed models are in the values considered acceptable in the hydrogen economy concept, being also compatible with the TADSEA design parameters. (author)

  19. Market Driven Design of Accelerator Systems for Sterilization of Medical Products.

    Science.gov (United States)

    Whitham, K.

    1997-05-01

    Historically, most scientific accelerator systems are the primary ingredient of a given facility. In commercial applications of accelerators the customers' needs are for a system in which the accelerator is a part of a process. In the case of the sterilization of medical products, the accelerator is part of a process which ensures a sterile dose to FDA standards to a variety of products. The process includes a variety of hardware and specifications for parameters that are unrelated to accelerator technology. In addition, the customers are in general unfamiliar with accelerator technology. This creates the need for a different approach to design including a multidisciplined group of designers as well as the need for the design of equipment that has industrial reliability, so as to be useable for long periods of time by relatively low skill operators. In addition, the systems must be highly cost efficient, because the accelerator technology will be competing with alternative technologies which invariably are less expensive. This paper describes the design of the TB 10/15 accelerator system which is currently being operated in several places around the world. The description includes the market needs that were addressed and how the system was designed to meet them. Log No. 3006

  20. The participation of IPEN in the IAEA coordinated research projects on accelerators driven systems (ADS)

    Energy Technology Data Exchange (ETDEWEB)

    Maiorino, J.R.; Santos, A.; Carluccio, T.; Rossi, P.C.R.; Antunes, A.; Oliveira, F. de; Lee, S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: maiorino@ipen.br

    2007-07-01

    This paper describes the participation of the IPEN in the International Atomic Energy Agency (IAEA) Coordinated Research Projects(CRP) on Analytical and Experimental Benchmark Analysis on ADS and Low Enriched Uranium Fuel Utilization in ADS. The first CRP has as specific objective to improve the present understanding of the coupling of an external neutron source [e.g. a spallation source in the case of the accelerator driven system (ADS)] with a multiplicative sub-critical core, and the second CRP, or collaborative work, the utilization of LEU in existing or planned ADS facilities. IPEN participate in both CRP through a research contract (13388), and although there are several benchmarks defined in both CRP, presently IPEN is participating in the activities related with reactor physics benchmark of the Yalina Booster facility in Belarus, in the analytical and numerical benchmarking of methods and codes for ADS kinetics, and in the ADS target calculations. Besides, since there are plans to introduce a compact neutron generator in a sub critical core of the IPEN-MB-01 facility, a benchmark of a simulation of such project has been proposed in the LEU-ADS CRP. The paper will review the CRPs with details on the activities in which IPEN is participating. (author)

  1. CFD Analysis and Design of Detailed Target Configurations for an Accelerator-Driven Subcritical System

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Adam; Merzari, Elia; Sofu, Tanju; Zhong, Zhaopeng; Gohar, Yousry

    2016-08-01

    High-fidelity analysis has been utilized in the design of beam target options for an accelerator driven subcritical system. Designs featuring stacks of plates with square cross section have been investigated for both tungsten and uranium target materials. The presented work includes the first thermal-hydraulic simulations of the full, detailed target geometry. The innovative target cooling manifold design features many regions with complex flow features, including 90 bends and merging jets, which necessitate three-dimensional fluid simulations. These were performed using the commercial computational fluid dynamics code STAR-CCM+. Conjugate heat transfer was modeled between the plates, cladding, manifold structure, and fluid. Steady-state simulations were performed but lacked good residual convergence. Unsteady simulations were then performed, which converged well and demonstrated that flow instability existed in the lower portion of the manifold. It was established that the flow instability had little effect on the peak plate temperatures, which were well below the melting point. The estimated plate surface temperatures and target region pressure were shown to provide sufficient margin to subcooled boiling for standard operating conditions. This demonstrated the safety of both potential target configurations during normal operation.

  2. Absolute reactivity calibration of accelerator-driven systems after RACE-T experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jammes, C. C. [Commissariat a l' Energie Atomique CEA, Centre de Cadarache, DEN/CAD/DER/SPEx/LPE, 13108 Saint Paul-Lez-Durance (France); Imel, G. R. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Geslot, B. [Commissariat a l' Energie Atomique CEA, Centre de Cadarache, DEN/CAD/DER/SPEx/LPE, 13108 Saint Paul-Lez-Durance (France); Rosa, R. [Ente per le Nuove Tecnologie, L' Energia e l' Ambiente, Centro della Casaccia, Via Anguillarese, 301, 00060 Roma I (Italy)

    2006-07-01

    The RACE-T experiments that were held in november 2005 in the ENEA-Casaccia research center near Rome allowed us to improve our knowledge of the experimental techniques for absolute reactivity calibration at either startup or shutdown phases of accelerator-driven systems. Various experimental techniques for assessing a subcritical level were inter-compared through three different subcritical configurations SC0, SC2 and SC3, about -0.5, -3 and -6 dollars, respectively. The area-ratio method based of the use of a pulsed neutron source appears as the most performing. When the reactivity estimate is expressed in dollar unit, the uncertainties obtained with the area-ratio method were less than 1% for any subcritical configuration. The sensitivity to measurement location was about slightly more than 1% and always less than 4%. Finally, it is noteworthy that the source jerk technique using a transient caused by the pulsed neutron source shutdown provides results in good agreement with those obtained from the area-ratio technique. (authors)

  3. Toward integrated laser-driven ion accelerator systems at the photo-medical research center in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, P.R., E-mail: bolton.paul@jaea.go.j [Photo-Medical Research Center, Japan Atomic Energy Agency, 8-1-7 Umemidai Kizugawa-shi, Kyoto 619-0215 (Japan); Hori, T.; Kiriyama, H.; Mori, M.; Sakaki, H. [Photo-Medical Research Center, Japan Atomic Energy Agency, 8-1-7 Umemidai Kizugawa-shi, Kyoto 619-0215 (Japan); Sutherland, K. [Hokkaido University, School of Medicine, Sapporo-shi, Kita-ku, Kita 12 Jo, Nishi 5 Chome 060-0812 (Japan); Suzuki, M. [Photo-Medical Research Center, Japan Atomic Energy Agency, 8-1-7 Umemidai Kizugawa-shi, Kyoto 619-0215 (Japan); Wu, J. [SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA (United States); Yogo, A. [Photo-Medical Research Center, Japan Atomic Energy Agency, 8-1-7 Umemidai Kizugawa-shi, Kyoto 619-0215 (Japan)

    2010-08-01

    Goals and early progress at the Photo-Medical Research Center are summarized. Laser-driven ion beam radiotherapy can require compact repetition-rated laser systems with peak powers approaching the PW level. Laser development at PMRC is outlined. Our parallel experimental and simulation efforts aimed at the development of a prototype ion beamline as an integrated laser-driven ion accelerator system are presented. In addition some of our first medical and radiobiological experimental investigations, proton-induced double strand breaking in human cancer cells and simulations of optimum dose distributions for ocular melanoma are discussed. Recommended components of a balanced and comprehensive PMRC agenda are given.

  4. Activity report of working party on reactor physics of accelerator-driven system. July 1999 to March 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Under the Research Committee on Reactor Physics, the Working Party on Reactor Physics of Accelerator-Driven System (ADS-WP) was set in July 1999 to review and investigate special subjects related to reactor physics research for the Accelerator-Driven Subcritical System (ADS). The ADS-WP, at the first meeting, discussed a guideline of its activity for two years and decided to concentrate upon three subjects: (1) neutron transport calculations in high energy range, (2) static and kinetic (safety-related) characteristics of subcritical system, and (3) system design including ADS concepts and elemental technology developments required. The activity of ADS-WP continued from July 1999 to March 2001. In this duration, the members of ADS-WP met together four times and discussed the above subjects. In addition, the ADS-WP conducted a questionnaire on requests and proposals for the plan of Transmutation Physics Experimental Facility in the High-Intensity Proton Accelerator Project, which is a joint project between JAERI and KEK (High Energy Accelerator Research Organization). This report summarizes the results obtained by the above ADS-WP activity. (author)

  5. Conceptual design of minor actinides burner with an accelerator-driven subcritical system.

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Y.; Gohar, Y. (Nuclear Engineering Division)

    2011-11-04

    In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS

  6. System and safety studies of accelerator driven transmutation. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J.; Chakarova, R.; Jollkonen, Mikael; Westlen, D. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2003-06-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the Dept. of Nuclear and Reactor Physics has been largely determined by the program of the European projects of the the 5th Framework Programme. In particular: a) ADS core design and development of advanced nuclear fuel optimized for high transmutation rates and good safety features. This activity includes computer modeling of nuclear fuel production. Three different ADS-core concept are being investigated: Conceptual design of Pb-Bi cooled core with nitride fuel - so called Sing-Sing Core; Pb-Bi cooled core with oxide fuel; Gas cooled core with oxide fuel - both designs investigated for the European Project PDS-XADS; b) analysis of ADS-dynamics and assessment of major reactivity feedbacks; c) emergency heat removal from ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE, YALINA subcritical experiment in Minsk and designing of the subcritical experiment SAD in Dubna; e) material studies for ADS, in particular theoretical and simulation studies of radiation damage in high neutron (or proton) fluxes; f) computer code and nuclear data development relevant for simulation and optimization of ADS, special efforts were put in the frame of the European Project PDS-XADS to perform sensitivity studies of the different nuclear data libraries; g) studies of transmutation potential of critical reactors in particular High Temp Gas Cooled Reactor. Most important finding and conclusions from our studies: A strong positive void coefficient was found for lead/bismuth cooled cores. This considerable void effect is attributed to a high fraction of americium (60%) in the fuel. It was found that void reactivity insertion rates increases with P/D; in response to the beam overpower accident the Pb/Bi-cooled core featured the twice longer grace time compared to the sodium-cooled core; an important safety issue is the high void worth that could

  7. Locomotion analysis of a vibration-driven system with three acceleration-controlled internal masses

    Directory of Open Access Journals (Sweden)

    Xiong Zhan

    2015-03-01

    Full Text Available The controlled motion of a rigid body in the horizontal plane is investigated in this article. Three internal and acceleration-controlled masses are used to actuate the system. Dry friction acting between the system and the plane is isotropic. The dynamics of two basic motions of the system, that is, rectilinear and rotary motions, are first studied. Then by combining these two basic types of motions, planar locomotion of the system is constructed. Two typical planar trajectories of the system, that is, oblique lines and curve lines, are proposed and both approached with folding lines. The slope of the oblique lines and the curvature of the curves can be adjusted by varying the drive parameters, and the planar locomotion is thus controlled. To achieve a maximum average velocity, the drive parameters are optimized.

  8. Study of particle transport in a high power spallation target for an accelerator-driven transmutation system

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, Nikhil Vittal

    2013-01-31

    AGATE is a project envisaged to demonstrate the feasibility of transmutation in a gas (helium) cooled accelerator-driven system using solid spallation target. Development of the spallation target module and assessing its safety aspects are studied in this work. According to the AGATE concept parameters, 600 MeV protons are delivered on to the segmented tungsten spallation target. The Monte Carlo toolkit Geant4 has been used in the simulation of particle transport. Binary cascade is used to simulate intra-nuclear cascades, along with the G4NDL neutron data library for low energy neutrons (<20 MeV).

  9. Accelerator-driven sub-critical reactor system (ADS) for nuclear ...

    Indian Academy of Sciences (India)

    ... as well as for nuclear energy generation utilizing thorium as fuel. In India, there is an interest in the programmes of development of high-energy and high-current accelerators due to the potential of ADS in utilizing the vast resources of thorium in the country for nuclear power generation. The accelerator related activities ...

  10. Neutronic design study of accelerator driven system (ADS) for Jordan subcritical reactor as a neutron source for nuclear research.

    Science.gov (United States)

    Xoubi, Ned

    2018-01-01

    In this paper, a preliminary neutronic design study of an accelerator driven subcritical system for Jordan Subcritical Assembly (JSA) is presented. The conceptual design of coupling the JSA core with proton accelerator and spallation target is investigated, and its feasibility as a neutron source for nuclear research, and possibly for target irradiation and isotope production evaluated. 3D MCNPX model of the JSA reactor, the accelerator beam, and the Pb target was developed, based on actual reactor parameters. MCNPX calculations were carried out to estimate the absolute radial and axial neutron flux in the reactor, and to calculate the multiplication factor K eff and heat generated in the reactor. Numerical results showed an enormous increase in the neutron flux, by seven orders of magnitude, compared to the current JSA core design using Pu-Be source. In this research the results obtained are discussed and compared with those of the JSA, and do confirm the feasibility of utilizing the JSA as a viable nuclear research facility with adequate neutron flux. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Experimental results from the VENUS-F critical reference state for the GUINEVERE accelerator driven system project

    Energy Technology Data Exchange (ETDEWEB)

    Uyttenhove, W.; Baeten, P.; Ban, G.; Billebaud, A.; Chabod, S.; Dessagne, P.; Kerveno, M.; Kochetkov, A.; Lecolley, F. R.; Lecouey, J. L.; Marie, N.; Mellier, F.; Steckmeyer, J. C.; Thyebault, H. E.; Vittiglio, G.; Wagemans, J. [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, BE-2400 Mol (Belgium)

    2011-07-01

    The GUINEVERE (Generation of Uninterrupted Intense Neutron pulses at the lead Venus Reactor) project was launched in 2006 within the framework of FP6 EUROTRANS in order to validate on-line reactivity monitoring and subcriticality level determination in Accelerator Driven Systems. Therefore the VENUS reactor at SCK.CEN in Mol (Belgium) was modified towards a fast core (VENUS-F) and coupled to the GENEPI-3C accelerator built by CNRS The accelerator can operate in both continuous and pulsed mode. The VENUS-F core is loaded with enriched Uranium and reflected with solid lead. A well-chosen critical reference state is indispensable for the validation of the on-line subcriticality monitoring methodology. Moreover a benchmarking tool is required for nuclear data research and code validation. In this paper the design and the importance of the critical reference state for the GUINEVERE project are motivated. The results of the first experimental phase on the critical core are presented. The control rods worth is determined by the rod drop technique and the application of the Modified Source Multiplication (MSM) method allows the determination of the worth of the safety rods. The results are implemented in the VENUS-F core certificate for full exploitation of the critical core. (authors)

  12. Monte Carlo studies of accelerator driven systems energy and spatial distribution of neutrons in multiplying and non-multiplying media

    CERN Document Server

    Hashemi-Nezhad, S R; Brandt, R; Krivopustov, M I; Kulakov, B A; Odoj, R; Sosnin, A N; Wan, J S; Westmeier, W

    2002-01-01

    The LAHET code system is used to study the behaviour of the spallation neutrons resulting from the interaction of 2.5 GeV/c protons with a massive lead target within a large (approx 32 m sup 3) lead and graphite moderating environments. The spatial and energy distribution of the neutrons with presence and absence of a fissile material in Accelerator Driven Systems (ADS) are investigated. It is shown that the energy spectra of the neutrons in graphite and lead moderators are very different and such difference is expected to result in noticeable differences in the nuclear waste transmutation abilities of the ADSs that use graphite and lead for neutron moderation and storage.

  13. Fermi Acceleration in driven relativistic billiards

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Rafael S., E-mail: rsoaresp@ifi.unicamp.br [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, 13083-970, Campinas, SP (Brazil); Letelier, Patricio S. [Departamento de Matematica Aplicada, Instituto de Matematica, Estatistica e Computacao Cientifica, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil)

    2011-08-29

    We show numerical experiments of driven billiards using special relativity. We have the remarkable fact that for the relativistic driven circular and annular concentric billiards, depending on initial conditions and parameters, we observe Fermi Acceleration, absent in the Newtonian case. The velocity for these cases tends to the speed of light very quickly. We find that for the annular eccentric billiard the initial velocity grows for a much longer time than the concentric annular billiard until it asymptotically reach c. -- Highlights: → Fermi Acceleration is studied for relativistic driven billiards. → We studied regular and chaotic billiards with different parameters. → Fermi Acceleration is present even for static regular billiards.

  14. Accelerator driven sub-critical core

    Science.gov (United States)

    McIntyre, Peter M; Sattarov, Akhdiyor

    2015-03-17

    Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

  15. The physics of accelerator driven sub-critical reactors

    Indian Academy of Sciences (India)

    Keywords. Accelerator driven systems; nuclear waste transmutation; computer codes; reactor physics; reactor noise; kinetics; burnup; transport theory; Monte Carlo; thorium utilization; neutron multiplication; sub-criticality; sub-critical facilities.

  16. Neutrino Physics with Accelerator Driven Subcritical Reactors

    Science.gov (United States)

    Ciuffoli, Emilio

    2017-09-01

    Accelerator Driven Subcritical System (ADS) reactors are being developed around the world, to produce energy and, at the same time, to provide an efficient way to dispose of and to recycle nuclear waste. Used nuclear fuel, by itself, cannot sustain a chain reaction; however in ADS reactors the additional neutrons which are required will be supplied by a high-intensity accelerator. This accelerator will produce, as a by-product, a large quantity of {\\bar{ν }}μ via muon Decay At Rest (µDAR). Using liquid scintillators, it will be possible to to measure the CP-violating phase δCP and to look for experimental signs of the presence of sterile neutrinos in the appearance channel, testing the LSND and MiniBooNE anomalies. Even in the first stage of the project, when the beam energy will be lower, it will be possible to produce {\\bar{ν }}e via Isotope Decay At Rest (IsoDAR), which can be used to provide competitive bounds on sterile neutrinos in the disappearance channel. I will consider several experimental setups in which the antineutrinos are created using accelerators that will be constructed as part of the China-ADS program.

  17. Proton-driven Plasma Wakefield Acceleration

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The construction of ever larger and costlier accelerator facilities has a limited future, and new technologies will be needed to push the energy frontier. Plasma wakefield acceleration is a rapidly developing field and is a promising candidate technology for future high energy colliders. We focus on the recently proposed idea of proton-driven plasma wakefield acceleration and describe the current status and plans for this approach.

  18. Subcritical Multiplication Parameters of the Accelerator-Driven System with 100 MeV Protons at the Kyoto University Critical Assembly

    OpenAIRE

    Jae-Yong Lim; Cheol Ho Pyeon; Takahiro Yagi; Tsuyoshi Misawa

    2012-01-01

    Basic experiments on the accelerator-driven system (ADS) at the Kyoto University Critical Assembly are carried out by combining a solid-moderated and -reflected core with the fixed-field alternating gradient accelerator. The reaction rates are measured by the foil activation method to obtain the subcritical multiplication parameters. The numerical calculations are conducted with the use of MCNPX and JENDL/HE-2007 to evaluate the reaction rates of activation foils set in the core region and at...

  19. Impact of intermediate and high energy nuclear data on the neutronic safety parameters of MYRRHA accelerator driven system

    Science.gov (United States)

    Stankovskiy, Alexey; Çelik, Yurdunaz; Eynde, Gert Van den

    2017-09-01

    Perturbation of external neutron source can cause significant local power changes transformed into undesired safety-related events in an accelerator driven system. Therefore for the accurate design of MYRRHA sub-critical core it is important to evaluate the uncertainty of power responses caused by the uncertainties in nuclear reaction models describing the particle transport from primary proton energy down to the evaluated nuclear data table range. The calculations with a set of models resulted in quite low uncertainty on the local power caused by significant perturbation of primary neutron yield from proton interactions with lead and bismuth isotopes. The considered accidental event of prescribed proton beam shape loss causes drastic increase in local power but does not practically change the total core thermal power making this effect difficult to detect. In the same time the results demonstrate a correlation between perturbed local power responses in normal operation and misaligned beam conditions indicating that generation of covariance data for proton and neutron induced neutron multiplicities for lead and bismuth isotopes is needed to obtain reliable uncertainties for local power responses.

  20. A neutron booster for spallation sources--application to accelerator driven systems and isotope production

    CERN Document Server

    Galy, J; Van Dam, H; Valko, J

    2002-01-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the mu m-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology--for example in the design neutron amplifiers for medical applications and 'fast' islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module cou...

  1. Microfabrication of Laser-Driven Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Benjamin M

    2003-04-07

    We discuss the potential for using microfabrication techniques for laser-driven accelerator construction. We introduce microfabrication processes in general, and then describe our investigation of a particular trial process. We conclude by considering the issues microfabrication raises for possible future structures.

  2. Accelerator-driven Transmutation of Waste

    Science.gov (United States)

    Venneri, Francesco

    1998-04-01

    Nuclear waste from commercial power plants contains large quantities of plutonium, other fissionable actinides, and long-lived fission products that are potential proliferation concerns and create challenges for the long-term storage. Different strategies for dealing with nuclear waste are being followed by various countries because of their geologic situations and their views on nuclear energy, reprocessing and non-proliferation. The current United States policy is to store unprocessed spent reactor fuel in a geologic repository. Other countries are opting for treatment of nuclear waste, including partial utilization of the fissile material contained in the spent fuel, prior to geologic storage. Long-term uncertainties are hampering the acceptability and eventual licensing of a geologic repository for nuclear spent fuel in the US, and driving up its cost. The greatest concerns are with the potential for radiation release and exposure from the spent fuel for tens of thousands of years and the possible diversion and use of the actinides contained in the waste for weapons construction. Taking advantage of the recent breakthroughs in accelerator technology and of the natural flexibility of subcritical systems, the Accelerator-driven Transmutation of Waste (ATW) concept offers the United States and other countries the possibility to greatly reduce plutonium, higher actinides and environmentally hazardous fission products from the waste stream destined for permanent storage. ATW does not eliminate the need for, but instead enhances the viability of permanent waste repositories. Far from being limited to waste destruction, the ATW concept also brings to the table new technologies that could be relevant for next-generation power producing reactors. In the ATW concept, spent fuel would be shipped to the ATW site where the plutonium, transuranics and selected long-lived fission products would be destroyed by fission or transmutation in their first and only pass through the

  3. Physics design of a 10 MeV injector test stand for an accelerator-driven subcritical system

    Directory of Open Access Journals (Sweden)

    Fang Yan

    2015-05-01

    Full Text Available The 10 MeV accelerator-driven subcritical system (ADS Injector I test stand at Institute of High Energy Physics (IHEP is a testing facility dedicated to demonstrate one of the two injector design schemes [Injector Scheme-I, which works at 325 MHz], for the ADS project in China. The injector is composed of two parts, the linac part and the beam dump line. The former is designed on the basis of 325 MHz four-vane type copper structure radio frequency quadrupole and superconducting (SC spoke cavities with β=0.12. The latter is designed to transport the beam coming out of the SC section of the linac to the beam dump, where the beam transverse profile is fairly enlarged and unformed to simplify the beam target design. The SC section consists of two cryomodules with 14 β=0.12 Spoke cavities, 14 solenoid and 14 BPMs in total. The first challenge in the physics design comes from the necessary space required for the cryomodule separation where the periodical lattice is destroyed at a relatively lower energy of ∼5  MeV. Another challenge is the beam dump line design, as it will be the first beam dump line being built by using a step field magnet for the transverse beam expansion and uniformity in the world. This paper gives an overview of the physics design study together with the design principles and machine construction considerations. The results of an optimized design, fabrication status and end to end simulations including machine errors are presented.

  4. Photonic Crystal Laser-Driven Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Benjamin M

    2007-08-22

    Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

  5. Intrinsic normalized emittance growth in laser-driven electron accelerators

    Directory of Open Access Journals (Sweden)

    M. Migliorati

    2013-01-01

    Full Text Available Laser-based electron sources are attracting strong interest from the conventional accelerator community due to their unique characteristics in terms of high initial energy, low emittance, and significant beam current. Extremely strong electric fields (up to hundreds of GV/m generated in the plasma allow accelerating gradients much higher than in conventional accelerators and set the basis for achieving very high final energies in a compact space. Generating laser-driven high-energy electron beam lines therefore represents an attractive challenge for novel particle accelerators. In this paper we show that laser-driven electrons generated by the nowadays consolidated TW laser systems, when leaving the interaction region, are subject to a very strong, normalized emittance worsening which makes them quickly unusable for any beam transport. Furthermore, due to their intrinsic beam characteristics, controlling and capturing the full beam current can only be achieved improving the source parameters.

  6. The physics of accelerator driven sub-critical reactors

    Indian Academy of Sciences (India)

    utilization; neutron multiplication; sub-criticality; sub-critical facilities. PACS Nos 89.30.Gg; 28.41.-I; 28.50.-k. 1. Introduction. Accelerator driven systems (ADS) are attracting worldwide attention increasingly due to their superior safety characteristics and their potential for burning actinide and fission product-waste and energy ...

  7. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  8. Energy efficiency of laser driven, structure based accelerators

    Directory of Open Access Journals (Sweden)

    R. H. Siemann

    2004-06-01

    Full Text Available The acceleration efficiency of a laser driven linear accelerator is analyzed. The laser power, loss factor, and impedances determine the maximum charge that can be accelerated and the efficiency of that acceleration. The accelerator structure can be incorporated into a laser cavity. The equation for the resultant laser pulse is derived and analyzed. A specific example is presented, and the steady-state laser pulse shapes, acceleration efficiency, and average unloaded gradient are calculated.

  9. On the significance of the energy correlations of spallation neutrons on the neutron fluctuations in accelerator-driven subcritical systems

    CERN Document Server

    Pázsit, I; Fhager, V

    2000-01-01

    Studies of neutron fluctuations in spallation-driven subcritical systems require the use of energy-dependent master equations. In particular, calculation of the second moment of the neutron distribution requires knowledge on the energy correlations (two-point distributions) of the source particles. It is shown here that such correlations will exist even if the energies of all neutrons, generated in any single spallation event, are independent, provided that the energy distribution of the neutrons for separate spallation events is dependent on the number of neutrons generated. A simple model of number dependence of the energy spectrum is constructed, and the arising energy correlations are calculated. The error in calculating the second moment of the neutron distribution, arising when assuming zero correlations (i.e. using only one-particle energy spectra), is estimated in a simple model of neutron slowing down.

  10. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    CERN Document Server

    Guo Shi Lun; Shi Yong Qian; Shen Qing Biao; Wan Jun Sheng; Brandt, R; Vater, P; Kulakov, B A; Krivopustov, M I; Sosnin, A N

    2002-01-01

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

  11. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    Energy Technology Data Exchange (ETDEWEB)

    Vivanco, R., E-mail: raul.vivanco.sanchez@gmail.com [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Ghiglino, A.; Vicente, J.P. de; Sordo, F.; Terrón, S.; Magán, M. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Perlado, J.M. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Bermejo, F.J. [Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain)

    2014-12-11

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final k{sub eff} value of around 0.9 after the 50 days cycle.

  12. Novel target design for enhanced laser driven proton acceleration

    Directory of Open Access Journals (Sweden)

    Malay Dalui

    2017-09-01

    Full Text Available We demonstrate a simple method of preparing structured target for enhanced laser-driven proton acceleration under target-normal-sheath-acceleration scheme. A few layers of genetically modified, clinically grown micron sized E. Coli bacteria cell coated on a thin metal foil has resulted in an increase in the maximum proton energy by about 1.5 times and the total proton yield is enhanced by approximately 25 times compared to an unstructured reference foil at a laser intensity of 1019 W/cm2. Particle-in-cell simulations on the system shows that the structures on the target-foil facilitates anharmonic resonance, contributing to enhanced hot electron production which leads to stronger accelerating field. The effect is observed to grow as the number of structures is increased in the focal area of the laser pulse.

  13. Novel target design for enhanced laser driven proton acceleration

    Science.gov (United States)

    Dalui, Malay; Kundu, M.; Tata, Sheroy; Lad, Amit D.; Jha, J.; Ray, Krishanu; Krishnamurthy, M.

    2017-09-01

    We demonstrate a simple method of preparing structured target for enhanced laser-driven proton acceleration under target-normal-sheath-acceleration scheme. A few layers of genetically modified, clinically grown micron sized E. Coli bacteria cell coated on a thin metal foil has resulted in an increase in the maximum proton energy by about 1.5 times and the total proton yield is enhanced by approximately 25 times compared to an unstructured reference foil at a laser intensity of 1019 W/cm2. Particle-in-cell simulations on the system shows that the structures on the target-foil facilitates anharmonic resonance, contributing to enhanced hot electron production which leads to stronger accelerating field. The effect is observed to grow as the number of structures is increased in the focal area of the laser pulse.

  14. Laser-driven proton acceleration with nanostructured targets

    Science.gov (United States)

    Vallières, Simon; Morabito, Antonia; Veltri, Simona; Scisciò, Massimiliano; Barberio, Marianna; Antici, Patrizio

    2017-05-01

    Laser-driven particle acceleration has become a growing field of research, in particular for its numerous interesting applications. One of the most common proton acceleration mechanism that is obtained on typically available multi-hundred TW laser systems is based on the irradiation of thin solid metal foils by the intense laser, generating the proton acceleration on its rear target surface. The efficiency of this acceleration scheme strongly depends on the type of target used. Improving the acceleration mechanism, i.e. enhancing parameters such as maximum proton energy, laminarity, efficiency, monocromaticy, and number of accelerated particles, is heavily depending on the laser-to-target absorption, where obviously cheap and easy to implement targets are best candidates. In this work, we present nanostructured targets that are able to increase the absorption of light compared to what can be achieved with a classical solid (non-nanostructured) target and are produced with a method that is much simpler and cheaper than conventional lithographic processes. Several layers of gold nanoparticles were deposited on solid targets (aluminum, Mylar and multiwalled carbon nanotube buckypaper) and allow for an increased photon absorption. This ultimately permits to increase the laser-to-particle energy transfer, and thus to enhance the yield in proton production. Experimental characterization results on the nanostructured films are presented (UV-Vis spectroscopy and AFM), along with preliminary experimental proton spectra obtained at the JLF-TITAN laser facility at LLNL.

  15. The mechanical design and fabrication of 162.5 MHz buncher for China accelerator driven sub-critical system injector II

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Hai Hua; Li, Youtang [Lanzhou University of Technology, Lanzhou (China); He, Yuan; Zhang, Bin; Huang, Shichun; Yuan, Chenzhang; Jia, Huan; Zhang, Shenghu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China)

    2017-08-15

    A buncher is one of the main pieces of equipment in the medium energy beam transport line (MEBT) for China accelerator driven sub-critical system (C-ADS) Injector II. To focus the beam longitudinally and match the beam for the acceptance of the superconducting linac section, two room temperature quarter wave resonator (QWR) bunchers with frequency of 162.5 MHz have been designed as parts of the MEBT. According to the beam transmission matching of the MEBT and the geometric parameters requirements of bunchers, the unique mechanical structure and the main processing technology of buncher cavities and their couplers and tuners are described in this paper. The fabrication of bunchers and their parts have been completed and tested at high power, the test results agree well with the design requirements. These bunchers work well for about two years in Institute of Modern Physics, Chinese Academy of Sciences.

  16. The mechanical design and fabrication of 162.5 MHz buncher for China accelerator driven sub-critical system injector II

    Directory of Open Access Journals (Sweden)

    Haihua Niu

    2017-08-01

    Full Text Available A buncher is one of the main pieces of equipment in the medium energy beam transport line (MEBT for China accelerator driven sub-critical system (C-ADS Injector II. To focus the beam longitudinally and match the beam for the acceptance of the superconducting linac section, two room temperature quarter wave resonator (QWR bunchers with frequency of 162.5 MHz have been designed as parts of the MEBT. According to the beam transmission matching of the MEBT and the geometric parameters requirements of bunchers, the unique mechanical structure and the main processing technology of buncher cavities and their couplers and tuners are described in this paper. The fabrication of bunchers and their parts have been completed and tested at high power, the test results agree well with the design requirements. These bunchers work well for about two years in Institute of Modern Physics, Chinese Academy of Sciences.

  17. YALINA facility a sub-critical Accelerator- Driven System (ADS) for nuclear energy research facility description and an overview of the research program (1997-2008).

    Energy Technology Data Exchange (ETDEWEB)

    Gohar, Y.; Smith, D. L.; Nuclear Engineering Division

    2010-04-28

    The YALINA facility is a zero-power, sub-critical assembly driven by a conventional neutron generator. It was conceived, constructed, and put into operation at the Radiation Physics and Chemistry Problems Institute of the National Academy of Sciences of Belarus located in Minsk-Sosny, Belarus. This facility was conceived for the purpose of investigating the static and dynamic neutronics properties of accelerator driven sub-critical systems, and to serve as a neutron source for investigating the properties of nuclear reactions, in particular transmutation reactions involving minor-actinide nuclei. This report provides a detailed description of this facility and documents the progress of research carried out there during a period of approximately a decade since the facility was conceived and built until the end of 2008. During its history of development and operation to date (1997-2008), the YALINA facility has hosted several foreign groups that worked with the resident staff as collaborators. The participation of Argonne National Laboratory in the YALINA research programs commenced in 2005. For obvious reasons, special emphasis is placed in this report on the work at YALINA facility that has involved Argonne's participation. Attention is given here to the experimental program at YALINA facility as well as to analytical investigations aimed at validating codes and computational procedures and at providing a better understanding of the physics and operational behavior of the YALINA facility in particular, and ADS systems in general, during the period 1997-2008.

  18. Subcritical Multiplication Parameters of the Accelerator-Driven System with 100 MeV Protons at the Kyoto University Critical Assembly

    Directory of Open Access Journals (Sweden)

    Jae-Yong Lim

    2012-01-01

    Full Text Available Basic experiments on the accelerator-driven system (ADS at the Kyoto University Critical Assembly are carried out by combining a solid-moderated and -reflected core with the fixed-field alternating gradient accelerator. The reaction rates are measured by the foil activation method to obtain the subcritical multiplication parameters. The numerical calculations are conducted with the use of MCNPX and JENDL/HE-2007 to evaluate the reaction rates of activation foils set in the core region and at the location of the target. Here, a comparison between the measured and calculated eigenvalues reveals a relative difference of around 10% in C/E values. A special mention is made of the fact that the reaction rate analyses in the subcritical systems demonstrate apparently the actual effect of moving the tungsten target into the core on neutron multiplication. A series of further ADS experiments with 100 MeV protons needs to be carried out to evaluate the accuracy of subcritical multiplication parameters.

  19. Radiological Impact of the TRIGA Accelerator-Driven Experiment (TRADE)

    OpenAIRE

    Herrera-Martínez, A; Ferrari, A.; Kadi, Y.; Zanini, L.; Parks, G. T.; Rubbia, Carlo; Burgio, N.; Carta, M; Santagata, A.; Cinotti, L

    2002-01-01

    The TRADE project, which is part of the European Roadmap towards the development of Accelerator Driven Systems (ADS), foresees the coupling of a 110 MeV, 2 mA proton cyclotron with the core of a 1 MW Triga research reactor. We performed radioprotection studies using two state-of-the-art computer code packages, FLUKA and EA-MC. We concentrated on the calculation of the neutron and particle flux and dose rates during normal operation as well as in the case of several possible accidents, in orde...

  20. Advanced approaches to high intensity laser-driven ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Henig, Andreas

    2010-04-26

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C{sup 6+} and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C{sup 6+} spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times

  1. Research opportunities with compact accelerator-driven neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.S. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Andreani, C., E-mail: carla.andreani@uniroma2.it [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); CNR-IPCF Sezione di Messina, Messina (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy); Carpenter, J.M. [Argonne National Laboratory, Argonne, IL (United States); Festa, G., E-mail: giulia.festa@uniroma2.it [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy); Gorini, G. [Università degli Studi di Milano—Bicocca, Milano (Italy); Loong, C.-K. [Università degli Studi di Roma “Tor Vergata”, Centro NAST, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Senesi, R. [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); CNR-IPCF Sezione di Messina, Messina (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy)

    2016-10-13

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target–moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  2. Research on accelerator-driven transmutation and studies of experimental facilities

    Energy Technology Data Exchange (ETDEWEB)

    Takizuka, Takakazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    JAERI is carrying out R and Ds on accelerator-driven transmutation systems under the national OMEGA Program that aims at development of the technology to improve efficiency and safety in the final disposal of radioactive waste. Research facilities for accelerator-driven transmutation experiments are proposed to construct within the framework of the planned JAERI Neutron Science Project. This paper describes the features of the proposed accelerator-driven transmutation systems and their technical issues to be solved. A research facility plan under examination is presented. The plan is divided in two phases. In the second phase, technical feasibility of accelerator-driven systems will be demonstrated with a 30-60 MW experimental integrated system and with a 7 MW high-power target facility. (author)

  3. Beam-driven, Plasma-based Particle Accelerators

    CERN Document Server

    Muggli, P.

    2016-01-01

    We briefly give some of the characteristics of the beam-driven, plasma-based particle accelerator known as the plasma wakefield accelerator (PWFA). We also mention some of the major results that have been obtained since the birth of the concept. We focus on high-energy particle beams where possible.

  4. Physics of Laser-driven plasma-based acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Esarey, Eric; Schroeder, Carl B.

    2003-06-30

    The physics of plasma-based accelerators driven by short-pulse lasers is reviewed. This includes the laser wake-field accelerator, the plasma beat wave accelerator, the self-modulated laser wake-field accelerator, and plasma waves driven by multiple laser pulses. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse direction, electron dephasing, laser pulse energy depletion, as well as beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and plasmas with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Recent experimental results are summarized.

  5. Dynamics of electron acceleration in laser-driven wakefields. Acceleration limits and asymmetric plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Popp, Antonia

    2011-12-16

    The experiments presented in this thesis study several aspects of electron acceleration in a laser-driven plasma wave. High-intensity lasers can efficiently drive a plasma wave that sustains electric fields on the order of 100 GV/m. Electrons that are trapped in this plasma wave can be accelerated to GeV-scale energies. As the accelerating fields in this scheme are 3-4 orders of magnitude higher than in conventional radio-frequency accelerators, the necessary acceleration distance can be reduced by the same factor, turning laser-wakefield acceleration (LWFA) into a promising compact, and potentially cheaper, alternative. However, laser-accelerated electron bunches have not yet reached the parameter standards of conventional accelerators. This work will help to gain better insight into the acceleration process and to optimize the electron bunch properties. The 25 fs, 1.8 J-pulses of the ATLAS laser at the Max-Planck-Institute of Quantum Optics were focused into a steady-state flow gas cell. This very reproducible and turbulence-free gas target allows for stable acceleration of electron bunches. Thus the sensitivity of electron parameters to subtle changes of the experimental setup could be determined with meaningful statistics. At optimized experimental parameters, electron bunches of {approx}50 pC total charge were accelerated to energies up to 450 MeV with a divergence of {approx}2 mrad FWHM. As, in a new design of the gas cell, its length can be varied from 2 to 14 mm, the electron bunch energy could be evaluated after different acceleration distances, at two different electron densities. From this evolution important acceleration parameters could be extracted. At an electron density of 6.43. 10{sup 18} cm{sup -3} the maximum electric field strength in the plasma wave was determined to be {approx}160 GV/m. The length after which the relativistic electrons outrun the accelerating phase of the electric field and are decelerated again, the so-called dephasing length

  6. Photonic crystal laser-driven accelerator structures

    CERN Document Server

    Cowan, Benjamin

    2005-01-01

    We discuss simulated photonic crystal structure designs, including two- and three-dimensional planar structures and fibers. The discussion of 2D structures demonstrates guiding of a speed-of-light accelerating mode by a defect in a photonic crystal lattice and reveals design considerations and trade-offs. With a three-dimensional lattice, we introduce a candidate geometry and discuss beam dynamics, coupling, and manufacturing techniques for that structure. In addition we discuss W-band scale tests of photonic crystal structures. The computational methods are also discussed.

  7. Accelerator driven sytems from the radiological safety point of view

    Science.gov (United States)

    Sarkar, P. K.; Nandy, Maitreyee

    2007-02-01

    In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead--bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community. Spallation reaction products like high energy gammas, neutrons, muons, pions and several radiotoxic nuclides including Po-210 complicate the situation. In the present paper, we discuss radiation safety measures like bulk shielding, containment of radiation leakage through ducts and penetration and induced activity in the structure to protect radiation workers as well as estimation of sky-shine, soil and ground water activation, release of toxic gases to the environment to protect public as per the stipulations of the regulatory authorities. We recommend the application of the probabilistic safety analysis technique by assessing the probability and criticality of different hazard-initiating events using HAZOP and FMECA.

  8. Burnup calculations using serpent code in accelerator driven thorium reactors

    Energy Technology Data Exchange (ETDEWEB)

    Korkmaz, M.E.; Agar, O. [Karamanoglu Mehmetbey Univ., Karaman (Turkey). Physics Dept.; Yigit, M. [Aksaray Univ. (Turkey). Physics Dept.

    2013-07-15

    In this study, burnup calculations have been performed for a sodium cooled Accelerator Driven Thorium Reactor (ADTR) using the Serpent 1.1.16 Monte Carlo code. The ADTR has been designed for burning minor actinides, mixed {sup 232}Th and mixed {sup 233}U fuels. A solid Pb-Bi spallation target in the center of the core is used and sodium as coolant. The system is designed for a heating power of 2 000 MW and for an operation time of 600 days. For burnup calculations the Advanced Matrix Exponential Method CRAM (Chebyshev Rational Approximation Method) and different nuclear data libraries (ENDF7, JEF2.2, JEFF3.1.1) were used. The effective multiplication factor change from 0.93 to 0.97 for different nuclear data libraries during the reactor operation period. (orig.)

  9. Accelerator-driven molten-salt blankets: Physics issues

    Energy Technology Data Exchange (ETDEWEB)

    Houts, M.G.; Beard, C.A.; Buksa, J.J.; Wiley Davidson, J.; Durkee, J.W.; Perry, R.T.; Poston, D.I. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1995-01-20

    A number of nuclear physics issues concerning the Los Alamos molten-salt, accelerator-driven plutonium converter are discussed. General descriptions of several concepts using internal and external moderation are presented. Burnup and salt processing requirement calculations are presented for four concepts, indicating that both the high power density externally moderated concept and an internally moderated concept achieve total plutonium burnups approaching 90% at salt processing rates of less than 2 m{sup 3} per year. Beginning-of-life reactivity temperature coefficients and system kinetic response are also discussed. Future research should investigate the effect of changing blanket composition on operational and safety characteristics. {copyright}American Institute of Physcis 1995

  10. Radiological Impact of the TRIGA Accelerator-Driven Experiment (TRADE)

    CERN Document Server

    Herrera-Martínez, A; Kadi, Y; Zanini, L; Parks, G T; Rubbia, Carlo; Burgio, N; Carta, M; Santagata, A; Cinotti, L

    2002-01-01

    The TRADE project, which is part of the European Roadmap towards the development of Accelerator Driven Systems (ADS), foresees the coupling of a 110 MeV, 2 mA proton cyclotron with the core of a 1 MW Triga research reactor. We performed radioprotection studies using two state-of-the-art computer code packages, FLUKA and EA-MC. We concentrated on the calculation of the neutron and particle flux and dose rates during normal operation as well as in the case of several possible accidents, in order to assess the radiation damage and define the design of key components of the facility, such as the beam-line shielding. Both high-energy particle interactions and low-energy neutron transport are treated with a sophisticated method based on a full Monte Carlo simulation, combined with the use of modern nuclear data libraries.

  11. Rate acceleration of light-driven rotary molecular motors

    NARCIS (Netherlands)

    Pollard, Michael M.; Klok, Martin; Pijper, Dirk; Feringa, Ben L.

    2007-01-01

    One of the key challenges in taking light-driven unidirectional rotary motors from discovery to application is to increase the rate of rotation. Herein, we review our ongoing efforts to address this issue by meticulous improvement to the molecular design. To accelerate the rotary cycle, we have

  12. Contribution to a proposition for a long term development of nuclear energy: the TASSE concept (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production); Contribution a une proposition d'un developpement a long terme de l'energie nucleaire: le concept TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy Production)

    Energy Technology Data Exchange (ETDEWEB)

    Berthou, V

    2000-10-30

    Nuclear industry creates waste which are in the middle of the discussion concerning the Nuclear Energy future. At this time, important decisions for the Energy production must be taken, so numerous researches are conducted within the framework of the Bataille law. The goal of these studies is to find a range of solutions concerning the waste management. An innovative system, called TASSE (Thorium based Accelerator driven System with Simplified fuel cycle for long term Energy production), is studied in this thesis. This reactor is included in a long term strategy, and is destined for the renewal of the reactor park. In the first part of this work, the main characteristics of TASSE have been defined. They are commensurate with some specific requirements such as: to insure a large time to the Nuclear Energy, to reduce the waste production in an important way, to eliminate waste already stocked in the present park, to insure the non proliferation, and to be economically competitive. Neutronics studies of TASSE have been done. A calculation procedure has been developed to reach the system equilibrium state. Several types of molten salts as well as a pebble-bed fuel have been studied. Thus, an optimal fuel has been brought out in regard to some parameters such as the burn up level, the spectrum, the waste toxicity, the cycle type. Eventually, various TASSE core layout have been envisaged. (author)

  13. Laser-driven particle acceleration towards radiobiology and medicine

    CERN Document Server

    2016-01-01

    This book deals with the new method of laser-driven acceleration for application to radiation biophysics and medicine. It provides multidisciplinary contributions from world leading scientist in order to assess the state of the art of innovative tools for radiation biology research and medical applications of ionizing radiation. The book contains insightful contributions on highly topical aspects of spatio-temporal radiation biophysics, evolving over several orders of magnitude, typically from femtosecond and sub-micrometer scales. Particular attention is devoted to the emerging technology of laser-driven particle accelerators and their applicatio to spatio-temporal radiation biology and medical physics, customization of non-conventional and selective radiotherapy and optimized radioprotection protocols.

  14. Proliferation Potential of Accelerator-Drive Systems: Feasibility Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Riendeau, C.D.; Moses, D.L.; Olson, A.P.

    1998-11-01

    Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation neutron sources and subcritical reactors. Energy and power requirements were calculated for a proton accelerator-driven neutron spallation source and subcritical reactors to produce a significant amount of fissile material--plutonium.

  15. Laser-driven dielectric electron accelerator for radiobiology researches

    Science.gov (United States)

    Koyama, Kazuyoshi; Matsumura, Yosuke; Uesaka, Mitsuru; Yoshida, Mitsuhiro; Natsui, Takuya; Aimierding, Aimidula

    2013-05-01

    In order to estimate the health risk associated with a low dose radiation, the fundamental process of the radiation effects in a living cell must be understood. It is desired that an electron bunch or photon pulse precisely knock a cell nucleus and DNA. The required electron energy and electronic charge of the bunch are several tens keV to 1 MeV and 0.1 fC to 1 fC, respectively. The smaller beam size than micron is better for the precise observation. Since the laser-driven dielectric electron accelerator seems to suite for the compact micro-beam source, a phase-modulation-masked-type laser-driven dielectric accelerator was studied. Although the preliminary analysis made a conclusion that a grating period and an electron speed must satisfy the matching condition of LG/λ = v/c, a deformation of a wavefront in a pillar of the grating relaxed the matching condition and enabled the slow electron to be accelerated. The simulation results by using the free FDTD code, Meep, showed that the low energy electron of 20 keV felt the acceleration field strength of 20 MV/m and gradually felt higher field as the speed was increased. Finally the ultra relativistic electron felt the field strength of 600 MV/m. The Meep code also showed that a length of the accelerator to get energy of 1 MeV was 3.8 mm, the required laser power and energy were 11 GW and 350 mJ, respectively. Restrictions on the laser was eased by adopting sequential laser pulses. If the accelerator is illuminated by sequential N pulses, the pulse power, pulse width and the pulse energy are reduced to 1/N, 1/N and 1/N2, respectively. The required laser power per pulse is estimated to be 2.2 GW when ten pairs of sequential laser pulse is irradiated.

  16. Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

    Science.gov (United States)

    Joshi, Chan; Malka, Victor

    2010-04-01

    The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage approach R M G M Trines, R Bingham, Z Najmudin

  17. Monoenergetic proton beams accelerated by a radiation pressure driven shock

    CERN Document Server

    Palmer, C A J; Pogorelsky, I; Babzien, M; Dudnikova, G I; Ispiriyan, M; Polyanskiy, M N; Schreiber, J; Shkolnikov, P; Yakimenko, V; Najmudin, Z

    2010-01-01

    High energy ion beams (> MeV) generated by intense laser pulses promise to be viable alternatives to conventional ion beam sources due to their unique properties such as high charge, low emittance, compactness and ease of beam delivery. Typically the acceleration is due to the rapid expansion of a laser heated solid foil, but this usually leads to ion beams with large energy spread. Until now, control of the energy spread has only been achieved at the expense of reduced charge and increased complexity. Radiation pressure acceleration (RPA) provides an alternative route to producing laser-driven monoenergetic ion beams. In this paper, we show the interaction of an intense infrared laser with a gaseous hydrogen target can produce proton spectra of small energy spread (~ 4%), and low background. The scaling of proton energy with the ratio of intensity over density (I/n) indicates that the acceleration is due to the shock generated by radiation-pressure driven hole-boring of the critical surface. These are the fi...

  18. Transformer ratio saturation in a beam-driven wakefield accelerator

    Science.gov (United States)

    Farmer, J. P.; Martorelli, R.; Pukhov, A.

    2015-12-01

    We show that for beam-driven wakefield acceleration, the linearly ramped, equally spaced train of bunches typically considered to optimise the transformer ratio only works for flat-top bunches. Through theory and simulation, we explain that this behaviour is due to the unique properties of the plasma response to a flat-top density profile. Calculations of the optimal scaling for a train of Gaussian bunches show diminishing returns with increasing bunch number, tending towards saturation. For a periodic bunch train, a transformer ratio of 23 was achieved for 50 bunches, rising to 40 for a fully optimised beam.

  19. Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C. B.; Esarey, E.; Benedetti, C.; Toth, Cs.; Geddes, C. G. R.; Leemans, W.P.

    2010-06-01

    Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration are discussed. Driver propagation is examined, as well as the effects of the excited plasma wave phase velocity. The driver coupling to subsequent plasma accelerator stages for high-energy physics applications is addressed.

  20. MEMS-based, RF-driven, compact accelerators

    Science.gov (United States)

    Persaud, A.; Seidl, P. A.; Ji, Q.; Breinyn, I.; Waldron, W. L.; Schenkel, T.; Vinayakumar, K. B.; Ni, D.; Lal, A.

    2017-10-01

    Shrinking existing accelerators in size can reduce their cost by orders of magnitude. Furthermore, by using radio frequency (RF) technology and accelerating ions in several stages, the applied voltages can be kept low paving the way to new ion beam applications. We make use of the concept of a Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) and have previously shown the implementation of its basic components using printed circuit boards, thereby reducing the size of earlier MEQALACs by an order of magnitude. We now demonstrate the combined integration of these components to form a basic accelerator structure, including an initial beam-matching section. In this presentation, we will discuss the results from the integrated multi-beam ion accelerator and also ion acceleration using RF voltages generated on-board. Furthermore, we will show results from Micro-Electro-Mechanical Systems (MEMS) fabricated focusing wafers, which can shrink the dimension of the system to the sub-mm regime and lead to cheaper fabrication. Based on these proof-of-concept results we outline a scaling path to high beam power for applications in plasma heating in magnetized target fusion and in neutral beam injectors for future Tokamaks. This work was supported by the Office of Science of the US Department of Energy through the ARPA-e ALPHA program under contracts DE-AC02-05CH11231.

  1. Solid hydrogen target for laser driven proton acceleration

    Science.gov (United States)

    Perin, J. P.; Garcia, S.; Chatain, D.; Margarone, D.

    2015-05-01

    The development of very high power lasers opens up new horizons in various fields, such as laser plasma acceleration in Physics and innovative approaches for proton therapy in Medicine. Laser driven proton acceleration is commonly based on the so-called Target Normal Sheath Acceleration (TNSA) mechanisms: a high power laser is focused onto a solid target (thin metallic or plastic foil) and interact with matter at very high intensity, thus generating a plasma; as a consequence "hot" electrons are produced and move into the forward direction through the target. Protons are generated at the target rear side, electrons try to escape from the target and an ultra-strong quasi-electrostatic field (~1TV/m) is generated. Such a field can accelerate protons with a wide energy spectrum (1-200 MeV) in a few tens of micrometers. The proton beam characteristics depend on the laser parameters and on the target geometry and nature. This technique has been validated experimentally in several high power laser facilities by accelerating protons coming from hydrogenated contaminant (mainly water) at the rear of metallic target, however, several research groups are investigating the possibility to perform experiments by using "pure" hydrogen targets. In this context, the low temperature laboratory at CEA-Grenoble has developed a cryostat able to continuously produce a thin hydrogen ribbon (from 40 to 100 microns thick). A new extrusion concept, without any moving part has been carried out, using only the thermodynamic properties of the fluid. First results and perspectives are presented in this paper.

  2. Influence of shock waves on laser-driven proton acceleration.

    Science.gov (United States)

    Lundh, O; Lindau, F; Persson, A; Wahlström, C-G; McKenna, P; Batani, D

    2007-08-01

    The influence of shock waves, driven by amplified spontaneous emission (ASE), on laser-accelerated proton beams is investigated. A local deformation, produced by a cold shock wave launched by the ablation pressure of the ASE pedestal, can under oblique laser irradiation significantly direct the proton beam toward the laser axis. This can be understood in the frame of target normal sheath acceleration as proton emission from an area of the target where the local target normal is shifted toward the laser axis. Hydrodynamic simulations and experimental data show that there exists a window in laser and target parameter space where the target can be significantly deformed and yet facilitate efficient proton acceleration. The dependence of the magnitude of the deflection on target material, foil thickness, and ASE pedestal intensity and duration is experimentally investigated. The deflection angle is found to increase with increasing ASE intensity and duration and decrease with increasing target thickness. In a comparison between aluminum and copper target foils, aluminum is found to yield a larger proton beam deflection. An analytic model is successfully used to predict the proton emission direction.

  3. Role of resistivity gradient in laser-driven ion acceleration

    Directory of Open Access Journals (Sweden)

    L. A. Gizzi

    2011-01-01

    Full Text Available It was predicted that, when a fast electron beam with some angular spread is normally incident on a resistivity gradient, magnetic field generation can occur that can inhibit beam propagation [A. R. Bell et al., Phys. Rev. E 58, 2471 (1998PLEEE81063-651X10.1103/PhysRevE.58.2471]. This effect can have consequences on the laser-driven ion acceleration. In the experiment reported here, we compare ion emission from laser irradiated coated and uncoated metal foils and we show that the ion beam from the coated target has a much smaller angular spread. Detailed hybrid numerical simulations confirm that the inhibition of fast electron transport through the resistivity gradient may explain the observed effect.

  4. Operation and reactivity measurements of an accelerator driven subcritical TRIGA reactor

    Science.gov (United States)

    O'Kelly, David Sean

    Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a full-scale accelerator driven subcritical system (ADSS). The experimental program provided a relatively low-cost substitute for the higher power and complexity of internationally proposed systems utilizing proton accelerators and spallation neutron sources for an advanced ADSS that may be used for the burning of high-level radioactive waste. Various instrumentation methods that permitted ADSS neutron flux monitoring in high gamma radiation fields were successfully explored and the data was used to evaluate the Stochastic Pulsed Feynman method for reactivity monitoring.

  5. E-Beam Driven Accelerators: Working Group Summary

    Energy Technology Data Exchange (ETDEWEB)

    Muggli, P.; /Southern California U.; Ng, J.S.T.; /SLAC

    2005-07-12

    The working group has identified the parameters of an afterburner based on the design of a future linear collider. The new design brings the center of mass energy of the collider from 1 to 2 TeV. The afterburner is located in the final focus section of the collider, operates at a gradient of {approx}4 GeV/m, and is only about 125 m long. Very important issues remain to be addressed, and include the physics and design of the positron side of the afterburner, as well as of the final focus system. Present plasma wakefield accelerator experiments have reached a level of maturity and of relevance to the afterburner, that make it timely to involve the high energy physics and accelerator community in the afterburner design process. The main result of this working group is the first integration of the designs of a future linear collider and an afterburner.

  6. Invited Review Article: “Hands-on” laser-driven ion acceleration: A primer for laser-driven source development and potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, J. [Lehrstuhl für Medizinphysik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München (Germany); Max-Planck-Institut für Quantenoptik Garching, Hans-Kopfermann-Str. 1, 85748 Garching bei München (Germany); Bolton, P. R.; Parodi, K. [Lehrstuhl für Medizinphysik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München (Germany)

    2016-07-15

    An overview of progress and typical yields from intense laser-plasma acceleration of ions is presented. The evolution of laser-driven ion acceleration at relativistic intensities ushers prospects for improved functionality and diverse applications which can represent a varied assortment of ion beam requirements. This mandates the development of the integrated laser-driven ion accelerator system, the multiple components of which are described. Relevant high field laser-plasma science and design of controlled optimum pulsed laser irradiation on target are dominant single shot (pulse) considerations with aspects that are appropriate to the emerging petawatt era. The pulse energy scaling of maximum ion energies and typical differential spectra obtained over the past two decades provide guidance for continued advancement of laser-driven energetic ion sources and their meaningful applications.

  7. Plasma dynamics and heating/acceleration during driven magnetic reconnection

    Science.gov (United States)

    Cheng, C. Z.; Ono, Y.; Inoue, S.; Horiuchi, R.

    2016-12-01

    Highlights of the plasma dynamics and energization during anti-parallel driven magnetic reconnection are presented. The MHD condition breaks down in the entire reconnection layer (the reconnection current layer, the separatrix region and the whole downstream), and the plasma dynamics is also significantly different from the results of the Hall-MHD model. In particular, we explain (1) how electron and ion dynamics decouple and how the charge separation and electrostatic electric field are produced in the reconnection current layer and outflow exhaust and around the separatrix regions, (2) how electrons and ions gain energy in the reconnection current layer, (3) why the electron outflow velocity in the reconnection exhaust reaches super-Alfvenic speed and the ion outflow velocity reaches Alfvenic speed and how the parallel electric field is produced around the separatrix region, (4) how electrons are accelerated by the parallel electric field to form electron beam around the separatrix region and flat-top distribution in the immediate upstream region of the current layer, and (5) how ions gain energy when they move across the separatrix region into the downstream. We will compare the simulation results with observations of MMS and Geotail satellites.

  8. Source-jerk method for application on ADS neutronics study The ADS is stated for Accelerator Driven sub-critical System

    CERN Document Server

    Zhu Qing Fu; Li Yi; Xia Pu; Zheng Wu Qing; Zhu Guo Sheng

    2003-01-01

    The paper is concerned in the source-jerk method used to measure the sub-criticality, and the sub-critical experiment facility, which is used for the study on the neutronics of ADS, driven by external neutron source sup 2 sup 5 sup 2 Cf. The effects of the location of neutron source and material buffer where is at the location of the pipe of proton beam and target of fission-product dispersion on the sub-criticality of reactor are studied by source-jerk method

  9. LAVENDER: A steady-state core analysis code for design studies of accelerator driven subcritical reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shengcheng; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn; Huang, Kai; He, Mingtao; Li, Xunzhao

    2014-10-15

    Highlights: • A new code system for design studies of accelerator driven subcritical reactors (ADSRs) is developed. • S{sub N} transport solver in triangular-z meshes, fine deletion analysis and multi-channel thermal-hydraulics analysis are coupled in the code. • Numerical results indicate that the code is reliable and efficient for design studies of ADSRs. - Abstract: Accelerator driven subcritical reactors (ADSRs) have been proposed and widely investigated for the transmutation of transuranics (TRUs). ADSRs have several special characteristics, such as the subcritical core driven by spallation neutrons, anisotropic neutron flux distribution and complex geometry etc. These bring up requirements for development or extension of analysis codes to perform design studies. A code system named LAVENDER has been developed in this paper. It couples the modules for spallation target simulation and subcritical core analysis. The neutron transport-depletion calculation scheme is used based on the homogenized cross section from assembly calculations. A three-dimensional S{sub N} nodal transport code based on triangular-z meshes is employed and a multi-channel thermal-hydraulics analysis model is integrated. In the depletion calculation, the evolution of isotopic composition in the core is evaluated using the transmutation trajectory analysis algorithm (TTA) and fine depletion chains. The new code is verified by several benchmarks and code-to-code comparisons. Numerical results indicate that LAVENDER is reliable and efficient to be applied for the steady-state analysis and reactor core design of ADSRs.

  10. Detailed experimental results for high-trapping efficiency and narrow energy spread in a laser-driven accelerator

    Directory of Open Access Journals (Sweden)

    W. D. Kimura

    2004-09-01

    Full Text Available Presented are details of the staged electron laser acceleration (STELLA experiment, which demonstrated high-trapping efficiency and narrow energy spread in a staged laser-driven accelerator. Trapping efficiencies of up to 80% and energy spreads down to 0.36% (1σ were demonstrated. The experiment validated an approach that may be suitable for the basic design of a laser-driven accelerator system. In this approach, a laser-driven modulator together with a chicane creates a train of microbunches spaced apart by the laser wavelength. These microbunches are sent into a second laser-driven accelerator designed to efficiently trap the microbunches in the ponderomotive potential well of the laser electric field while maintaining a narrow energy spread. The STELLA scientific apparatus and procedures are described in detail. In-depth comparisons between the data and model are given including the predicted energy spectrum, energy-phase plot, and microbunch length profile. Data and model comparisons as a function of the phase delay between the microbunches and the accelerating wave are presented. The model is exercised to reveal how the high-trapping efficiency process evolves during the acceleration process.

  11. Divergence of the chaotic layer width and strong acceleration of the spatial chaotic transport in periodic systems driven by an adiabatic ac force.

    Science.gov (United States)

    Soskin, S M; Yevtushenko, O M; Mannella, R

    2005-11-25

    We show for the first time that a weak perturbation in a Hamiltonian system may lead to an arbitrarily wide chaotic layer and fast chaotic transport. This generic effect occurs in any spatially periodic Hamiltonian system subject to a sufficiently slow ac force. We explain it and develop an explicit theory for the layer width, verified in simulations. Chaotic spatial transport as well as applications to the diffusion of particles on surfaces, threshold devices, and others are discussed.

  12. New methods for high current fast ion beam production by laser-driven acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Margarone, D.; Krasa, J.; Prokupek, J.; Velyhan, A.; Laska, L.; Jungwirth, K.; Mocek, T.; Korn, G.; Rus, B. [Institute of Physics, ASCR, v.v.i., PALS Centre, Prague (Czech Republic); Torrisi, L.; Gammino, S.; Cirrone, P.; Cutroneo, M.; Romano, F. [INFN-Laboratori Nazionali del Sud, Catania, Messina University (Italy); Picciotto, A.; Serra, E. [Fondazione Bruno Kessler - IRST, Trento (Italy); Giuffrida, L. [CELIA, Centre Lasers Intenses et Applications (France); Mangione, A. [ITA - Istituto Tecnologie Avanzate, Trapani (Italy); Rosinski, M.; Parys, P. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); and others

    2012-02-15

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10{sup 16}-10{sup 19} W/cm{sup 2}. The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  13. New methods for high current fast ion beam production by laser-driven acceleration.

    Science.gov (United States)

    Margarone, D; Krasa, J; Prokupek, J; Velyhan, A; Torrisi, L; Picciotto, A; Giuffrida, L; Gammino, S; Cirrone, P; Cutroneo, M; Romano, F; Serra, E; Mangione, A; Rosinski, M; Parys, P; Ryc, L; Limpouch, J; Laska, L; Jungwirth, K; Ullschmied, J; Mocek, T; Korn, G; Rus, B

    2012-02-01

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10(16)-10(19) W∕cm(2). The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  14. Digital BPM Systems for Hadron Accelerators

    CERN Document Server

    Belleman, J; Kasprowicz, G; Raich, U

    2009-01-01

    The CERN Proton Synchrotron has been fitted with a new trajectory measurement system (TMS). Analogue signals from forty beam position monitors are digitized at 125MS/s, and then further treated entirely in the digital domain to derive the positions of all individual particle bunches on the fly. Large FPGAs handle all digital processing. The system fits in fourteen plug-in modules distributed over three half-width cPCI crates. Data are stored in circular buffers of large enough size to keep a fewseconds-worth of position data. Multiple clients can then request selected portions of the data, possibly representing many thousands of consecutive turns, for display on operator consoles. The system uses digital phase-locked loops to derive its beamlocked timing reference. Programmable state machines, driven by accelerator timing pulses and information from the accelerator control system, direct the order of operations. The cPCI crates are connected to a standard Linux computer by means of a private Gigabit Ethernet ...

  15. Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures

    Energy Technology Data Exchange (ETDEWEB)

    Byer, Robert L. [Stanford Univ., CA (United States). Edward L. Ginzton Lab.

    2013-11-07

    The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

  16. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Gschwendtner, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V.K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P.N.; Burt, G.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A.A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Huther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K.V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V.A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Oz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z.M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A.P.; Spitsyn, R.I.; Trines, R.; Tuev, P.V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C.P.; Wing, M.; Xia, G.; Zhang, H.

    2016-01-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  17. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Gschwendtner, E. [CERN, Geneva (Switzerland); Adli, E. [University of Oslo, Oslo 0316 (Norway); Amorim, L. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal); Apsimon, R. [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Lancaster University, Lancaster LA1 4YR (United Kingdom); Assmann, R. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Bachmann, A.-M.; Batsch, F. [Max Planck Institute for Physics, Föhringer Ring 6, München 80805 (Germany); Bauche, J. [CERN, Geneva (Switzerland); Berglyd Olsen, V.K. [University of Oslo, Oslo 0316 (Norway); Bernardini, M. [CERN, Geneva (Switzerland); Bingham, R. [STFC Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Biskup, B. [CERN, Geneva (Switzerland); Czech Technical University, Zikova 1903/4, 166 36 Praha 6 (Czech Republic); Bohl, T.; Bracco, C. [CERN, Geneva (Switzerland); Burrows, P.N. [John Adams Institute for Accelerator Science, Oxford (United Kingdom); University of Oxford, Oxford OX1 2JD (United Kingdom); Burt, G. [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Buttenschön, B. [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, Greifswald 17491 (Germany); Butterworth, A. [CERN, Geneva (Switzerland); Caldwell, A. [Max Planck Institute for Physics, Föhringer Ring 6, München 80805 (Germany); Cascella, M. [UCL, Gower Street, London WC1E 6BT (United Kingdom); and others

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  18. Supersonic micro-jets and their application to few-cycle laser-driven electron acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Karl

    2009-07-23

    This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. The laser system employed in this work is a new development based on optical parametric chirped pulse amplification and is the only multi-TW few-cycle laser in the world. In the experiment, the laser beam is focused onto a supersonic helium gas jet which leads to the formation of a plasma channel. The laser pulse, having an intensity of 10{sup 19} W/cm{sup 2} propagates through the plasma with an electron density of 2 x 10{sup 19} cm{sup -3} and forms via a highly nonlinear interaction a strongly anharmonic plasma wave. The amplitude of the wave is so large that the wave breaks, thereby injecting electrons from the background plasma into the accelerating phase. The energy transfer from the laser pulse to the plasma is so strong that the maximum propagation distance is limited to the 100 m range. Therefore, gas jets specifically tuned to these requirements have to be employed. The properties of microscopic supersonic gas jets are thoroughly analyzed in this work. Based on numeric flow simulation, this study encompasses several extensive parameter studies that illuminate all relevant features of supersonic flows in microscopic gas nozzles. This allowed the optimized design of de Laval nozzles with exit diameters ranging from 150 {mu}m to 3 mm. The employment of these nozzles in the experiment greatly improved the electron beam quality. After these optimizations, the laser-driven electron accelerator now yields monoenergetic electron pulses with energies up to 50 MeV and charges between one and ten pC. The electron beam has a typical divergence of 5 mrad and comprises an energy spectrum that is virtually free from low energetic background. The electron pulse duration could not yet be determined experimentally but simulations point towards values in the range of 1 fs. The acceleration gradient is estimated from simulation and experiment to be approximately 0.5 TV/m. The

  19. Ultrashort laser pulse driven inverse free electron laser accelerator experiment

    Directory of Open Access Journals (Sweden)

    J. T. Moody

    2016-02-01

    Full Text Available In this paper we discuss the ultrashort pulse high gradient inverse free electron laser accelerator experiment carried out at the Lawrence Livermore National Laboratory which demonstrated gradients exceeding 200  MV/m using a 4 TW 100 fs long 800 nm Ti:Sa laser pulse. Due to the short laser and electron pulse lengths, synchronization was determined to be one of the main challenges in this experiment. This made necessary the implementation of a single-shot, nondestructive, electro-optic sampling based diagnostics to enable time-stamping of each laser accelerator shot with <100  fs accuracy. The results of this experiment are expected to pave the way towards the development of future GeV-class IFEL accelerators.

  20. The Fermilab Accelerator control system

    Science.gov (United States)

    Bogert, Dixon

    1986-06-01

    With the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab Accelerators. The current system is based on making as large an amount of data as possible available to many operators or end-users. Specifically there are about 100 000 separate readings, settings, and status and control registers in the various machines, all of which can be accessed by seventeen consoles, some in the Main Control Room and others distributed throughout the complex. A "Host" computer network of approximately eighteen PDP-11/34's, seven PDP-11/44's, and three VAX-11/785's supports a distributed data acquisition system including Lockheed MAC-16's left from the original Main Ring and Booster instrumentation and upwards of 1000 Z80, Z8002, and M68000 microprocessors in dozens of configurations. Interaction of the various parts of the system is via a central data base stored on the disk of one of the VAXes. The primary computer-hardware communication is via CAMAC for the new Tevatron and Antiproton Source; certain subsystems, among them vacuum, refrigeration, and quench protection, reside in the distributed microprocessors and communicate via GAS, an in-house protocol. An important hardware feature is an accurate clock system making a large number of encoded "events" in the accelerator supercycle available for both hardware modules and computers. System software features include the ability to save the current state of the machine or any subsystem and later restore it or compare it with the state at another time, a general logging facility to keep track of specific variables over long periods of time, detection of "exception conditions" and the posting of alarms, and a central filesharing capability in which files on VAX disks are available for access by any of the "Host" processors.

  1. A Proton-Driven Plasma Wakefield Acceleration experiment at CERN

    CERN Multimedia

    The AWAKE Collaboration has been formed in order to demonstrate protondriven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2016 and this will be followed by an initial 3–4 yea...

  2. High power ring methods and accelerator driven subcritical reactor application

    Energy Technology Data Exchange (ETDEWEB)

    Tahar, Malek Haj [Univ. of Grenoble (France)

    2016-08-07

    High power proton accelerators allow providing, by spallation reaction, the neutron fluxes necessary in the synthesis of fissile material, starting from Uranium 238 or Thorium 232. This is the basis of the concept of sub-critical operation of a reactor, for energy production or nuclear waste transmutation, with the objective of achieving cleaner, safer and more efficient process than today’s technologies allow. Designing, building and operating a proton accelerator in the 500-1000 MeV energy range, CW regime, MW power class still remains a challenge nowadays. There is a limited number of installations at present achieving beam characteristics in that class, e.g., PSI in Villigen, 590 MeV CW beam from a cyclotron, SNS in Oakland, 1 GeV pulsed beam from a linear accelerator, in addition to projects as the ESS in Europe, a 5 MW beam from a linear accelerator. Furthermore, coupling an accelerator to a sub-critical nuclear reactor is a challenging proposition: some of the key issues/requirements are the design of a spallation target to withstand high power densities as well as ensure the safety of the installation. These two domains are the grounds of the PhD work: the focus is on the high power ring methods in the frame of the KURRI FFAG collaboration in Japan: upgrade of the installation towards high intensity is crucial to demonstrate the high beam power capability of FFAG. Thus, modeling of the beam dynamics and benchmarking of different codes was undertaken to validate the simulation results. Experimental results revealed some major losses that need to be understood and eventually overcome. By developing analytical models that account for the field defects, one identified major sources of imperfection in the design of scaling FFAG that explain the important tune variations resulting in the crossing of several betatron resonances. A new formula is derived to compute the tunes and properties established that characterize the effect of the field imperfections on the

  3. Multi-proton bunch driven hollow plasma wakefield acceleration in the nonlinear regime

    Science.gov (United States)

    Li, Yangmei; Xia, Guoxing; Lotov, Konstantin V.; Sosedkin, Alexander P.; Hanahoe, Kieran; Mete-Apsimon, Oznur

    2017-10-01

    Proton-driven plasma wakefield acceleration has been demonstrated in simulations to be capable of accelerating particles to the energy frontier in a single stage, but its potential is hindered by the fact that currently available proton bunches are orders of magnitude longer than the plasma wavelength. Fortunately, proton micro-bunching allows driving plasma waves resonantly. In this paper, we propose using a hollow plasma channel for multiple proton bunch driven plasma wakefield acceleration and demonstrate that it enables the operation in the nonlinear regime and resonant excitation of strong plasma waves. This new regime also involves beneficial features of hollow channels for the accelerated beam (such as emittance preservation and a uniform accelerating field) and long buckets of stable deceleration for the drive beam. The regime is attained at a proper ratio between plasma skin depth, driver radius, hollow channel radius, and micro-bunch period.

  4. Accelerator-driven Medical Sterilization to Replace Co-60 Sources

    Energy Technology Data Exchange (ETDEWEB)

    Kroc, Thomas K. [Fermilab; Thangaraj, Jayakar C.T. [Fermilab; Penning, Richard T. [Fermilab; Kephart, Robert D. [Fermilab

    2017-08-11

    This report documents the results of a study prepared at the request of the Office of Radiological Security of the National Nuclear Security Administration (NNSA), as part of the Domestic Protect and Reduce mission by the Illinois Accelerator Research Center (IARC) of Fermi National Accelerator Laboratory. The study included a literature survey of over 80 relevant documents and articles including industry standards, regulatory documents, technical papers, a court case, previous task force reports and industry white papers. The team also conducted interviews or had conversations with over 40 individuals representing over a dozen organizations over the course of its 10-month program. This report summarizes our findings, addresses the specific questions posed to us by NNSA, and concludes with a list of actionable recommendations.

  5. Advances in laser driven accelerator R&D

    Energy Technology Data Exchange (ETDEWEB)

    Leemans, Wim

    2004-08-23

    Current activities (last few years) at different laboratories, towards the development of a laser wakefield accelerator (LWFA) are reviewed, followed by a more in depth discussion of results obtained at the L'OASIS laboratory of LBNL. Recent results on laser guiding of relativistically intense beams in preformed plasma channels are discussed. The observation of mono-energetic beams in the 100 MeV energy range, produced by a channel guided LWFA at LBNL, is described and compared to results obtained in the unguided case at LOA, RAL and LBNL. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator has a very beneficial impact on the electron energy distribution. Progress on laser triggered injection is reviewed. Results are presented on measurements of bunch duration and emittance of the accelerated electron beams, that indicate the possibility of generating femtosecond duration electron bunches. Future challenges and plans towards the development of a 1 GeV LWFA module are discussed.

  6. Design of an electron-accelerator-driven compact neutron source for non-destructive assay

    Science.gov (United States)

    Murata, A.; Ikeda, S.; Hayashizaki, N.

    2017-09-01

    The threat of nuclear and radiological terrorism remains one of the greatest challenges to international security, and the threat is constantly evolving. In order to prevent nuclear terrorism, it is important to avoid unlawful import of nuclear materials, such as uranium and plutonium. Development of technologies for non-destructive measurement, detection and recognition of nuclear materials is essential for control at national borders. At Tokyo Institute of Technology, a compact neutron source system driven by an electron-accelerator has been designed for non-destructive assay (NDA). This system is composed of a combination of an S-band (2.856 GHz) RF-gun, a tungsten target to produce photons by bremsstrahlung, a beryllium target, which is suitable for use in generating neutrons because of the low threshold energy of photonuclear reactions, and a moderator to thermalize the fast neutrons. The advantage of this system can accelerate a short pulse beam with a pulse width less than 1 μs which is difficult to produce by neutron generators. The amounts of photons and neutron produced by electron beams were simulated using the Monte Carlo simulation code PHITS 2.82. When the RF-gun is operated with an average electron beam current of 0.1 mA, it is expected that the neutron intensities are 1.19 × 109 n/s and 9.94 × 109 n/s for incident electron beam energies of 5 MeV and 10 MeV, respectively.

  7. A "slingshot" laser-driven acceleration mechanism of plasma electrons

    CERN Document Server

    Fiore, Gaetano; Fedele, Renato

    2016-01-01

    We briefly report on the recently proposed [G. Fiore, R. Fedele, U. de Angelis, Phys. Plasmas 21 (2014), 113105], [G. Fiore, S. De Nicola, arXiv:1509.04656] electron acceleration mechanism named "slingshot effect": under suitable conditions the impact of an ultra-short and ultra-intense laser pulse against the surface of a low-density plasma is expected to cause the expulsion of a bunch of superficial electrons with high energy in the direction opposite to that of the pulse propagation; this is due to the interplay of the huge ponderomotive force, huge longitudinal field arising from charge separation, and the finite size of the laser spot.

  8. Research Programme for the 660 Mev Proton Accelerator Driven MOX-Plutonium Subcritical Assembly

    CERN Document Server

    Barashenkov, V S; Buttseva, G L; Dudarev, S Yu; Polanski, A; Puzynin, I V; Sissakian, A N

    2000-01-01

    The paper presents a research programme of the Experimental Acclerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton acceletator operating at the Laboratory of Nuclear Problems of the JINR, Dubna. MOX fuel (25% PuO_2 + 75% UO_2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core of a nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient k_eff = 0.945, energetic gain G = 30 and the accelerator beam power 0.5 kW.

  9. Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, K.P.; Wu, Z.; /SLAC; Cowan, B.M.; /Tech-X, Boulder; Hanuka, A.; /SLAC /Technion; Makasyuk, I.V.; /SLAC; Peralta, E.A.; Soong, K.; Byer, R.L.; /Stanford U.; England, R.J.; /SLAC

    2016-06-27

    Acceleration of electrons using laser-driven dielectric microstructures is a promising technology for the miniaturization of particle accelerators. In this work, experimental results are presented of relativistic electron acceleration with 690±100 MVm-1 gradient. This is a record-high accelerating gradient for a dielectric microstructure accelerator, nearly doubling the previous record gradient. To reach higher acceleration gradients the present experiment employs 90 fs duration laser pulses.

  10. Acceleration dynamics of ions in shocks and solitary waves driven by intense laser pulses.

    Science.gov (United States)

    He, Min-Qing; Dong, Quan-Li; Sheng, Zheng-Ming; Weng, Su-Ming; Chen, Min; Wu, Hui-Chun; Zhang, Jie

    2007-09-01

    The acceleration of ions in collisionless electrostatic shocks and solitary waves, driven by ultrashort intense laser pulses in a thin solid target under different conditions, is investigated theoretically. When a shock is formed, ions with certain initial velocities inside the target can be accelerated by the electrostatic field at the shock front to twice the shock speed. When a solitary wave is formed, only ions located at the rear surface of the target can be accelerated by the solitary wave together with the sheath field formed there.

  11. High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator

    Science.gov (United States)

    Li, Y.; Xia, G.; Lotov, K. V.; Sosedkin, A. P.; Hanahoe, K.; Mete-Apsimon, O.

    2017-10-01

    Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse fields varying both radially and in time, the witness beam quality is still far from suitable for practical application in future colliders. Here we demonstrate the efficient acceleration of electrons in proton-driven wakefields in a hollow plasma channel. In this regime, the witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions. We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with a preserved normalized emittance in a single channel of 700 m. This high-quality and high-charge beam may pave the way for the development of future plasma-based energy frontier colliders.

  12. The Spallation Neutron Source accelerator system design

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, S., E-mail: stuarth@fnal.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Abraham, W. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Aleksandrov, A. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Allen, C. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Alonso, J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Anderson, D. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Arenius, D. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Arthur, T. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Assadi, S. [Techsource, Inc., 1475 Central Avenue, Suite 250, Los Alamos, NM 87544-3291 (United States); Ayers, J.; Bach, P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Badea, V. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Battle, R. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Beebe-Wang, J. [Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-5000 (United States); Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); and others

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ∼100 high-power RF power systems, a 2 K cryogenic plant, ∼400 DC and pulsed power supply systems, ∼400 beam diagnostic devices and a distributed control system handling ∼100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  13. The Spallation Neutron Source accelerator system design

    Science.gov (United States)

    Henderson, S.; Abraham, W.; Aleksandrov, A.; Allen, C.; Alonso, J.; Anderson, D.; Arenius, D.; Arthur, T.; Assadi, S.; Ayers, J.; Bach, P.; Badea, V.; Battle, R.; Beebe-Wang, J.; Bergmann, B.; Bernardin, J.; Bhatia, T.; Billen, J.; Birke, T.; Bjorklund, E.; Blaskiewicz, M.; Blind, B.; Blokland, W.; Bookwalter, V.; Borovina, D.; Bowling, S.; Bradley, J.; Brantley, C.; Brennan, J.; Brodowski, J.; Brown, S.; Brown, R.; Bruce, D.; Bultman, N.; Cameron, P.; Campisi, I.; Casagrande, F.; Catalan-Lasheras, N.; Champion, M.; Champion, M.; Chen, Z.; Cheng, D.; Cho, Y.; Christensen, K.; Chu, C.; Cleaves, J.; Connolly, R.; Cote, T.; Cousineau, S.; Crandall, K.; Creel, J.; Crofford, M.; Cull, P.; Cutler, R.; Dabney, R.; Dalesio, L.; Daly, E.; Damm, R.; Danilov, V.; Davino, D.; Davis, K.; Dawson, C.; Day, L.; Deibele, C.; Delayen, J.; DeLong, J.; Demello, A.; DeVan, W.; Digennaro, R.; Dixon, K.; Dodson, G.; Doleans, M.; Doolittle, L.; Doss, J.; Drury, M.; Elliot, T.; Ellis, S.; Error, J.; Fazekas, J.; Fedotov, A.; Feng, P.; Fischer, J.; Fox, W.; Fuja, R.; Funk, W.; Galambos, J.; Ganni, V.; Garnett, R.; Geng, X.; Gentzlinger, R.; Giannella, M.; Gibson, P.; Gillis, R.; Gioia, J.; Gordon, J.; Gough, R.; Greer, J.; Gregory, W.; Gribble, R.; Grice, W.; Gurd, D.; Gurd, P.; Guthrie, A.; Hahn, H.; Hardek, T.; Hardekopf, R.; Harrison, J.; Hatfield, D.; He, P.; Hechler, M.; Heistermann, F.; Helus, S.; Hiatt, T.; Hicks, S.; Hill, J.; Hill, J.; Hoff, L.; Hoff, M.; Hogan, J.; Holding, M.; Holik, P.; Holmes, J.; Holtkamp, N.; Hovater, C.; Howell, M.; Hseuh, H.; Huhn, A.; Hunter, T.; Ilg, T.; Jackson, J.; Jain, A.; Jason, A.; Jeon, D.; Johnson, G.; Jones, A.; Joseph, S.; Justice, A.; Kang, Y.; Kasemir, K.; Keller, R.; Kersevan, R.; Kerstiens, D.; Kesselman, M.; Kim, S.; Kneisel, P.; Kravchuk, L.; Kuneli, T.; Kurennoy, S.; Kustom, R.; Kwon, S.; Ladd, P.; Lambiase, R.; Lee, Y. Y.; Leitner, M.; Leung, K.-N.; Lewis, S.; Liaw, C.; Lionberger, C.; Lo, C. C.; Long, C.; Ludewig, H.; Ludvig, J.; Luft, P.; Lynch, M.; Ma, H.; MacGill, R.; Macha, K.; Madre, B.; Mahler, G.; Mahoney, K.; Maines, J.; Mammosser, J.; Mann, T.; Marneris, I.; Marroquin, P.; Martineau, R.; Matsumoto, K.; McCarthy, M.; McChesney, C.; McGahern, W.; McGehee, P.; Meng, W.; Merz, B.; Meyer, R.; Meyer, R.; Miller, B.; Mitchell, R.; Mize, J.; Monroy, M.; Munro, J.; Murdoch, G.; Musson, J.; Nath, S.; Nelson, R.; Nelson, R.; O`Hara, J.; Olsen, D.; Oren, W.; Oshatz, D.; Owens, T.; Pai, C.; Papaphilippou, I.; Patterson, N.; Patterson, J.; Pearson, C.; Pelaia, T.; Pieck, M.; Piller, C.; Plawski, T.; Plum, M.; Pogge, J.; Power, J.; Powers, T.; Preble, J.; Prokop, M.; Pruyn, J.; Purcell, D.; Rank, J.; Raparia, D.; Ratti, A.; Reass, W.; Reece, K.; Rees, D.; Regan, A.; Regis, M.; Reijonen, J.; Rej, D.; Richards, D.; Richied, D.; Rode, C.; Rodriguez, W.; Rodriguez, M.; Rohlev, A.; Rose, C.; Roseberry, T.; Rowton, L.; Roybal, W.; Rust, K.; Salazer, G.; Sandberg, J.; Saunders, J.; Schenkel, T.; Schneider, W.; Schrage, D.; Schubert, J.; Severino, F.; Shafer, R.; Shea, T.; Shishlo, A.; Shoaee, H.; Sibley, C.; Sims, J.; Smee, S.; Smith, J.; Smith, K.; Spitz, R.; Staples, J.; Stein, P.; Stettler, M.; Stirbet, M.; Stockli, M.; Stone, W.; Stout, D.; Stovall, J.; Strelo, W.; Strong, H.; Sundelin, R.; Syversrud, D.; Szajbler, M.; Takeda, H.; Tallerico, P.; Tang, J.; Tanke, E.; Tepikian, S.; Thomae, R.; Thompson, D.; Thomson, D.; Thuot, M.; Treml, C.; Tsoupas, N.; Tuozzolo, J.; Tuzel, W.; Vassioutchenko, A.; Virostek, S.; Wallig, J.; Wanderer, P.; Wang, Y.; Wang, J. G.; Wangler, T.; Warren, D.; Wei, J.; Weiss, D.; Welton, R.; Weng, J.; Weng, W.-T.; Wezensky, M.; White, M.; Whitlatch, T.; Williams, D.; Williams, E.; Wilson, K.; Wiseman, M.; Wood, R.; Wright, P.; Wu, A.; Ybarrolaza, N.; Young, K.; Young, L.; Yourd, R.; Zachoszcz, A.; Zaltsman, A.; Zhang, S.; Zhang, W.; Zhang, Y.; Zhukov, A.

    2014-11-01

    The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ~100 high-power RF power systems, a 2 K cryogenic plant, ~400 DC and pulsed power supply systems, ~400 beam diagnostic devices and a distributed control system handling ~100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

  14. Towards the final BSA modeling for the accelerator-driven BNCT facility at INFN LNL

    Energy Technology Data Exchange (ETDEWEB)

    Ceballos, C. [Centro de Aplicaciones Tecnlogicas y Desarrollo Nuclear, 5ta y30, Miramar, Playa, Ciudad Habana (Cuba); Esposito, J., E-mail: juan.esposito@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P.; Conte, V.; Moro, D. [INFN, Laboratori Nazionali di Legnaro (LNL), via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Some remarkable advances have been made in the last years on the SPES-BNCT project of the Istituto Nazionale di Fisica Nucleare (INFN) towards the development of the accelerator-driven thermal neutron beam facility at the Legnaro National Laboratories (LNL), aimed at the BNCT experimental treatment of extended skin melanoma. The compact neutron source will be produced via the {sup 9}Be(p,xn) reactions using the 5 MeV, 30 mA beam driven by the RFQ accelerator, whose modules construction has been recently completed, into a thick beryllium target prototype already available. The Beam Shaping Assembly (BSA) final modeling, using both neutron converter and the new, detailed, Be(p,xn) neutron yield spectra at 5 MeV energy recently measured at the CN Van de Graaff accelerator at LNL, is summarized here.

  15. On fusion driven systems (FDS) for transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Aagren, O (Uppsala Univ., Aangstroem laboratory, div. of electricity, Uppsala (Sweden)); Moiseenko, V.E. (Inst. of Plasma Physics, National Science Center, Kharkov Inst. of Physics and Technology, Kharkov (Ukraine)); Noack, K. (Forschungszentrum Dresden-Rossendorf (Germany))

    2008-10-15

    This report gives a brief description of ongoing activities on fusion driven systems (FDS) for transmutation of the long-lived radioactive isotopes in the spent nuclear waste from fission reactors. Driven subcritical systems appears to be the only option for efficient minor actinide burning. Driven systems offer a possibility to increase reactor safety margins. A comparatively simple fusion device could be sufficient for a fusion-fission machine, and transmutation may become the first industrial application of fusion. Some alternative schemes to create strong fusion neutron fluxes are presented

  16. Ion acceleration in non-equilibrium plasmas driven by fast drifting electron

    Energy Technology Data Exchange (ETDEWEB)

    Castro, G. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Di Bartolo, F., E-mail: fdibartolo@unime.it [Università di Messina, V.le F. Stagno D’Alcontres 31, 98166, Messina (Italy); Gambino, N. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Metodologie Fisiche e Chimiche per L’ingegneria, Viale A.Doria 6, 95125 Catania (Italy); Mascali, D. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Romano, F.P. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CNR-IBAM Via Biblioteca 4, 95124 Catania (Italy); Anzalone, A.; Celona, L.; Gammino, S. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Di Giugno, R. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Lanaia, D. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Miracoli, R. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S.Sofia 64, 95123 Catania (Italy); Serafino, T. [CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Tudisco, S. [INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy)

    2013-05-01

    We hereby present results on ion acceleration mechanisms in non equilibrium plasmas generated by microwaves or high intensity laser pulses. Experiments point out that in magnetized plasmas X–B conversion takes place for under resonance values of the magnetic field, i.e. an electromagnetic mode is converted into an electrostatic wave. The strong self-generated electric field, of the order of 10{sup 7} V/m, causes a E × B drift which accelerates both ions and electrons, as it is evident by localized sputtering in the plasma chamber. These fields are similar (in magnitude) to the ones obtainable in laser generated plasmas at intensity of 10{sup 12} W/cm{sup 2}. In this latter case, we observe that the acceleration mechanism is driven by electrons drifting much faster than plasma bulk, thus generating an extremely strong electric field ∼10{sup 7} V/m. The two experiments confirm that ions acceleration at low energy is possible with table-top devices and following complementary techniques: i.e. by using microwave-driven (producing CW beams) plasmas, or non-equilibrium laser-driven plasmas (producing pulsed beams). Possible applications involve ion implantation, materials surface modifications, ion beam assisted lithography, etc.

  17. Tailored electron bunches with smooth current profiles for enhanced transformer ratios in beam-driven acceleration

    Directory of Open Access Journals (Sweden)

    F. Lemery

    2015-08-01

    Full Text Available Collinear high-gradient O(GV/m beam-driven wakefield methods for charged-particle acceleration could be critical to the realization of compact, cost-efficient, accelerators, e.g., in support of TeV-scale lepton colliders or multiple-user free-electron laser facilities. To make these options viable, the high accelerating fields need to be complemented with large transformer ratios >2, a parameter characterizing the efficiency of the energy transfer between a wakefield-exciting “drive” bunch to an accelerated “witness” bunch. While several potential current distributions have been discussed, their practical realization appears challenging due to their often discontinuous nature. In this paper we propose several alternative continuously differentiable (smooth current profiles which support enhanced transformer ratios. We especially demonstrate that one of the devised shapes can be implemented in a photo-emission electron source by properly shaping the photocathode-laser pulse. We finally discuss a possible superconducting linear-accelerator concept that could produce shaped drive bunches at high-repetition rates to drive a dielectric-wakefield accelerator with accelerating fields on the order of ∼60  MV/m and a transformer ratio ∼5 consistent with a recently proposed multiuser free-electron laser facility.

  18. High-flux electron beams from laser wakefield accelerators driven by petawatt lasers

    Science.gov (United States)

    Zeng, Ming; Tesileanu, Ovidiu

    2017-07-01

    Laser wakefield accelerators (LWFAs) are considered to be one of the most competitive next-generation accelerator candidates. In this paper, we will study the potential high-flux electron beam production of an LWFA driven by petawatt-level laser pulses. In our three-dimensional particle-in-cell simulations, an optimal set of parameters gives ˜ 40 {nC} of charge with 2 {PW} laser power, thus ˜ 400 {kA} of instantaneous current if we assume the electron beam duration is 100 fs. This high flux and its secondary radiation are widely applicable in nuclear and QED physics, industrial imaging, medical and biological studies.

  19. Three-dimensional dielectric photonic crystal structures for laser-driven acceleration

    Directory of Open Access Journals (Sweden)

    Benjamin M. Cowan

    2008-01-01

    Full Text Available We present the design and simulation of a three-dimensional photonic crystal waveguide for linear laser-driven acceleration in vacuum. The structure confines a synchronous speed-of-light accelerating mode in both transverse dimensions. We report the properties of this mode, including sustainable gradient and optical-to-beam efficiency. We present a novel method for confining a particle beam using optical fields as focusing elements. This technique, combined with careful structure design, is shown to have a large dynamic aperture and minimal emittance growth, even over millions of optical wavelengths.

  20. Sensitivity Analysis of Core Neutronic Parameters in Electron Accelerator-driven Subcritical Advanced Liquid Metal Reactor

    OpenAIRE

    Ebrahimkhani, Marziye; Hassanzadeh, Mostafa; Feghhi, Sayed Amier Hossian; Masti, Darush

    2016-01-01

    Calculation of the core neutronic parameters is one of the key components in all nuclear reactors. In this research, the energy spectrum and spatial distribution of the neutron flux in a uranium target have been calculated. In addition, sensitivity of the core neutronic parameters in accelerator-driven subcritical advanced liquid metal reactors, such as electron beam energy (Ee) and source multiplication coefficient (ks), has been investigated. A Monte Carlo code (MCNPX_2.6) has been used to ...

  1. Protection of Accelerator Hardware: RF systems

    CERN Document Server

    Kim, S.-H.

    2016-01-01

    The radio-frequency (RF) system is the key element that generates electric fields for beam acceleration. To keep the system reliable, a highly sophisticated protection scheme is required, which also should be designed to ensure a good balance between beam availability and machine safety. Since RF systems are complex, incorporating high-voltage and high-power equipment, a good portion of machine downtime typically comes from RF systems. Equipment and component damage in RF systems results in long and expensive repairs. Protection of RF system hardware is one of the oldest machine protection concepts, dealing with the protection of individual high-power RF equipment from breakdowns. As beam power increases in modern accelerators, the protection of accelerating structures from beam-induced faults also becomes a critical aspect of protection schemes. In this article, an overview of the RF system is given, and selected topics of failure mechanisms and examples of protection requirements are introduced.

  2. Coulomb-driven energy boost of heavy ions for laser-plasma acceleration.

    Science.gov (United States)

    Braenzel, J; Andreev, A A; Platonov, K; Klingsporn, M; Ehrentraut, L; Sandner, W; Schnürer, M

    2015-03-27

    An unprecedented increase of kinetic energy of laser accelerated heavy ions is demonstrated. Ultrathin gold foils have been irradiated by an ultrashort laser pulse at a peak intensity of 8×10^{19}  W/  cm^{2}. Highly charged gold ions with kinetic energies up to >200  MeV and a bandwidth limited energy distribution have been reached by using 1.3 J laser energy on target. 1D and 2D particle in cell simulations show how a spatial dependence on the ion's ionization leads to an enhancement of the accelerating electrical field. Our theoretical model considers a spatial distribution of the ionization inside the thin target, leading to a field enhancement for the heavy ions by Coulomb explosion. It is capable of explaining the energy boost of highly charged ions, enabling a higher efficiency for the laser-driven heavy ion acceleration.

  3. Ion acceleration in "dragging field" of a light-pressure-driven piston

    CERN Document Server

    Ji, Liangliang; Shen, Baifei

    2013-01-01

    We propose a new acceleration scheme that combines shock wave acceleration (SWA) and light pressure acceleration (LPA). When a thin foil driven by light pressure of an ultra-intense laser pulse propagates in underdense background plasma, it serves as a shock-like piston, trapping and reflecting background protons to ultra-high energies. Unlike in SWA, the piston velocity is not limited by the Mach number and can be highly relativistic. Background protons can be trapped and reflected forward by the enormous "dragging field" potential behind the piston which is not employed in LPA. Our one- and two-dimensional particle-in-cell simulations and analytical model both show that proton energies of several tens to hundreds of GeV can be obtained, while the achievable energy in simple LPA is below 10 GeV.

  4. Test-driven modeling of embedded systems

    DEFF Research Database (Denmark)

    Munck, Allan; Madsen, Jan

    2015-01-01

    To benefit maximally from model-based systems engineering (MBSE) trustworthy high quality models are required. From the software disciplines it is known that test-driven development (TDD) can significantly increase the quality of the products. Using a test-driven approach with MBSE may have...... a similar positive effect on the quality of the system models and the resulting products and may therefore be desirable. To define a test-driven model-based systems engineering (TD-MBSE) approach, we must define this approach for numerous sub disciplines such as modeling of requirements, use cases......, scenarios, behavior, architecture, etc. In this paper we present a method that utilizes the formalism of timed automatons with formal and statistical model checking techniques to apply TD-MBSE to the modeling of system architecture and behavior. The results obtained from applying it to an industrial case...

  5. The Approach of Blended Learning to cope with E and T Needs in the Nuclear Engineering Field in an International Environmental. The experience of the Design and Implementation of a Distance Pilot Course on Accelerator Driven Systems within FP7 ENEN III Project Framework

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M.; Gonzalez, E. M.; Sanz, J.; Ogando, F.; Sanchez-Elvira, A.

    2013-07-01

    In these days Education and Training (Eand T) worldwide is redirecting towards the design of a balanced combination of face-to-face and distance teaching, taking advantage of the new tools for Information and Communication Technologies (ICT), in what we know as blended learning. Our University is been devoted to blended learning already for 41 years, Thus, our participation in FP7 ENEN III project gave us the opportunity to offer distance teaching and learning for international EandT in the nuclear field taking into account UNED long experience. The development of ENEN III Training Schemes (TS) highlighted a significant lack of international courses in TS-D: Concepts and Design of GEN IV nuclear reactors. Additionally, no distance course was offered. Our long collaboration UNED-CIEMAT on Accelerator Driven Systems (ADS) and the support of our Instituto Universitario de Educacion a Distancia (IUED), experts in online teaching and learning, moved us to develop the full-distance international course Accelerator Driven Systems for advanced nuclear waste transmutation, within the project framework.

  6. Theoretical and experimental studies of plasma channel generation for beam driven plasma wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Tauscher, Gabriele; Mehrling, Timon [University of Hamburg (Germany); Aschikhin, Alexander; Erbe, Jan-Hendrik; Goldberg, Lars; Schwinkendorf, Jan-Patrick [University of Hamburg (Germany); Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Dale, John; Schaper, Lucas; Streeter, Matthew; Schmidt, Bernhard; Osterhoff, Jens [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany)

    2016-07-01

    Plasma-based wakefield acceleration is a promising approach in shrinking the size and cost of future particle accelerators and free-electron lasers. In the FLASHForward project a wakefield accelerator will be driven by an electron bunch from the FLASH accelerator while a multi-TW short pulse laser will pre-ionise a hydrogen gas target to form a plasma. Disentangling the processes of ionisation and wakefield driving enables improved control over the plasma density profiles and therefore over the structure of the wakefields crucially effecting the quality of the accelerated beams. To work out the electron density distribution in the target, we compute the ionisation rates of hydrogen molecules in strong laser fields. To be able to benchmark the predicted behaviour experimentally we also take into account the temporal and spatial laser-intensity profile evolution. The here developed understanding of the underlying processes of plasma generation ultimately allows for tailoring of the focusing geometry and laser-power-profile evolution to achieve desired plasma properties. As a proof of concept, we aim to realise plasmas with tailored shapes experimentally early 2016.

  7. 9 GeV Energy Gain in a Beam-Driven Plasma Wakefield Accelerator

    CERN Document Server

    Litos, M; Allen, J M; An, W; Clarke, C I; Corde, S; Clayton, C E; Frederico, J; Gessner, S J; Green, S Z; Hogan, M J; Joshi, C; Lu, W; Marsh, K A; Mori, W B; Schmeltz, M; Vafaei-Najafabadi, N; Yakimenko, V

    2015-01-01

    An electron beam has gained a maximum energy of 9 GeV per particle in a 1.3 m-long electron beam-driven plasma wakefield accelerator. The amount of charge accelerated in the spectral peak was 28.3 pC, and the root-mean-square energy spread was 5.0%. The mean accelerated charge and energy gain per particle of the 215 shot data set was 115 pC and 5.3 GeV, respectively, corresponding to an acceleration gradient of 4.0 GeV/m at the spectral peak. The mean energy spread of the data set was 5.1%. These results are consistent with the extrapolation of the previously reported energy gain results using a shorter, 36 cm-long plasma source to within 10%, evincing a non-evolving wake structure that can propagate distances of over a meter in length. Wake-loading effects were evident in the data through strong dependencies observed between various spectral properties and the amount of accelerated charge.

  8. Tendon Driven Finger Actuation System

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); hide

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  9. Quantitative system validation in model driven design

    DEFF Research Database (Denmark)

    Hermanns, Hilger; Larsen, Kim Guldstrand; Raskin, Jean-Francois

    2010-01-01

    The European STREP project Quasimodo1 develops theory, techniques and tool components for handling quantitative constraints in model-driven development of real-time embedded systems, covering in particular real-time, hybrid and stochastic aspects. This tutorial highlights the advances made, focus...

  10. Feasibility of an XUV FEL Oscillator Driven by a SCRF Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H.; Freund, H. P.; Reinsch, M.

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermi National Accelerator Laboratory. Using a1-ms-long macropulse composed of up to 3000 micropulses, and with beam energies projected from 45 to 800 MeV, the possibility for an extreme ultraviolet (XUV) free-electron laser oscillator (FELO) with the higher energy is evaluated. We have used both GINGER with an oscillator module and the MEDUSA/OPC code to assess FELO saturation prospects at 120 nm, 40 nm, and 13.4 nm. The results support saturation at all of these wavelengths which are also shorter than the demonstrated shortest wavelength record of 176 nm from a storage-ring-based FELO. This indicates linac-driven FELOs can be extended into this XUV wavelength regime previously only reached with single-pass FEL configurations.

  11. Density bunching effects in a laser-driven, near-critical density plasma for ion acceleration

    Science.gov (United States)

    Ettlinger, Oliver; Sahai, Aakash; Hicks, George; Ditter, Emma-Jane; Dover, Nicholas; Chen, Yu-Hsin; Helle, Michael; Gordon, Daniel; Ting, Antonio; Polyanskiy, Mikhail; Pogorelsky, Igor; Babzien, Marcus; Najmudin, Zulfikar

    2016-10-01

    We present work investigating the interaction of relativistic laser pulses with near-critical density gas targets exhibiting pre-plasma scale lengths of several laser wavelengths. Analytical and computational modelling suggest that the interaction dynamics in a low-Z plasma is a direct result of induced density bunching up to the critical surface. In fact, these bunches can themselves become overcritical and experience significant radiation pressure, accelerating ions to higher energies compared to an ``idealised'' plasma slab target. This work will be used to help explain the observation of ion energies exceeding those predicted by radiation pressure driven hole-boring in recent experiments using the TW CO2 laser at the Accelerator Test Facility at Brookhaven National Laboratory.

  12. Ultra-high-energy cosmic ray acceleration in engine-driven relativistic supernovae.

    Science.gov (United States)

    Chakraborti, S; Ray, A; Soderberg, A M; Loeb, A; Chandra, P

    2011-02-01

    The origin of ultra-high-energy cosmic rays (UHECRs) remains an enigma. They offer a window to new physics, including tests of physical laws at energies unattainable by terrestrial accelerators. They must be accelerated locally, otherwise, background radiations would severely suppress the flux of protons and nuclei, at energies above the Greisen-Zatsepin-Kuzmin (GZK) limit. Nearby, gamma ray bursts (GRBs), hypernovae, active galactic nuclei and their flares have all been suggested and debated as possible sources. A local sub-population of type Ibc supernovae (SNe) with mildly relativistic outflows have been detected as sub-energetic GRBs, X-ray flashes and recently as radio afterglows without detected GRB counterparts. Here, we measure the size-magnetic field evolution, baryon loading and energetics, using the observed radio spectra of SN 2009bb. We place such engine-driven SNe above the Hillas line and establish that they can readily explain the post-GZK UHECRs.

  13. Model Driven Development of Data Sensitive Systems

    DEFF Research Database (Denmark)

    Olsen, Petur

    2014-01-01

    Model-driven development strives to use formal artifacts during the development process. Formal artifacts enables automatic analyses of some aspects of the system under development. This serves to increase the understanding of the (intended) behavior of the system as well as increasing error...... to the values of variables. This theses strives to improve model-driven development of such data-sensitive systems. This is done by addressing three research questions. In the first we combine state-based modeling and abstract interpretation, in order to ease modeling of data-sensitive systems, while allowing...... detection and pushing error detection to earlier stages of development. The complexity of modeling and the size of systems which can be analyzed is severely limited when introducing data variables. The state space grows exponentially in the number of variable and the domain size of the variables...

  14. Modeling laser-driven electron acceleration using WARP with Fourier decomposition

    Science.gov (United States)

    Lee, P.; Audet, T. L.; Lehe, R.; Vay, J.-L.; Maynard, G.; Cros, B.

    2016-09-01

    WARP is used with the recent implementation of the Fourier decomposition algorithm to model laser-driven electron acceleration in plasmas. Simulations were carried out to analyze the experimental results obtained on ionization-induced injection in a gas cell. The simulated results are in good agreement with the experimental ones, confirming the ability of the code to take into account the physics of electron injection and reduce calculation time. We present a detailed analysis of the laser propagation, the plasma wave generation and the electron beam dynamics.

  15. Influence of the ablation threshold fluence on laser-driven acceleration

    Science.gov (United States)

    Margarone, D.; Velyhan, A.; Torrisi, L.; Cutroneo, M.; Giuffrida, L.; Picciotto, A.; Krasa, J.; Cavallaro, S.; Limpouch, J.; Klimo, O.; Psikal, J.; Proska, J.; Novotny, F.

    2013-05-01

    Laser ablation threshold measurements has been carried out by the nanosecond-class Nd:YAG laser at LNS-INFN in Catania. Advanced targets, such as hydrogen-enriched silicon slabs and sub-micro structured polymeric samples, have been investigated. The estimated ablation fluences are correlated to recent experimental and theoretical results on high intensity laser driven ion acceleration. Characteristics of H-atoms/protons and heavier atoms/ions coming out from the bulk of the irradiated target or from surface contaminants have been determined by optical and time-of-flight spectroscopy as well as mass quadrupole spectrometry.

  16. Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets.

    Science.gov (United States)

    Obst, Lieselotte; Göde, Sebastian; Rehwald, Martin; Brack, Florian-Emanuel; Branco, João; Bock, Stefan; Bussmann, Michael; Cowan, Thomas E; Curry, Chandra B; Fiuza, Frederico; Gauthier, Maxence; Gebhardt, René; Helbig, Uwe; Huebl, Axel; Hübner, Uwe; Irman, Arie; Kazak, Lev; Kim, Jongjin B; Kluge, Thomas; Kraft, Stephan; Loeser, Markus; Metzkes, Josefine; Mishra, Rohini; Rödel, Christian; Schlenvoigt, Hans-Peter; Siebold, Mathias; Tiggesbäumker, Josef; Wolter, Steffen; Ziegler, Tim; Schramm, Ulrich; Glenzer, Siegfried H; Zeil, Karl

    2017-08-31

    We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150 TW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20 MeV with particle numbers exceeding 10 9 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (∅ 5 μm) and planar (20 μm × 2 μm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions.

  17. AWAKE Design Report: A Proton-Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Caldwell, A; Lotov, K; Muggli, P; Wing, M

    2013-01-01

    The AWAKE Collaboration has been formed in order to demonstrate proton driven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2015 and this will be followed by an initial 3–4 ye...

  18. Simulations of laser-driven ion acceleration from a thin CH target

    Science.gov (United States)

    Park, Jaehong; Bulanov, Stepan; Ji, Qing; Steinke, Sven; Treffert, Franziska; Vay, Jean-Luc; Schenkel, Thomas; Esarey, Eric; Leemans, Wim; Vincenti, Henri

    2017-10-01

    2D and 3D computer simulations of laser driven ion acceleration from a thin CH foil using code WARP were performed. As the foil thickness varies from a few nm to μm, the simulations confirm that the acceleration mechanism transitions from the RPA (radiation pressure acceleration) to the TNSA (target normal sheath acceleration). In the TNSA regime, with the CH target thickness of 1 μ m and a pre-plasma ahead of the target, the simulations show the production of the collimated proton beam with the maximum energy of about 10 MeV. This agrees with the experimental results obtained at the BELLA laser facility (I 5 × 18 W / cm2 , λ = 800 nm). Furthermore, the maximum proton energy dependence on different setups of the initialization, i.e., different angles of the laser incidence from the target normal axis, different gradient scales and distributions of the pre-plasma, was explored. This work was supported by LDRD funding from LBNL, provided by the U.S. DOE under Contract No. DE-AC02-05CH11231, and used resources of the NERSC, a DOE office of Science User Facility supported by the U.S. DOE under Contract No. DE-AC02-05CH11231.

  19. Superconducting linear accelerator system for NSC

    Indian Academy of Sciences (India)

    Superconducting linear accelerator system for NSC. P N PRAKASH, T S DATTA, B P AJITH KUMAR, J ANTONY, P BARUA,. J CHACKO, A CHOUDHURY, G K CHADHARI, S GHOSH, S KAR,. S A KRISHNAN, MANOJ KUMAR, RAJESH KUMAR, A MANDAL,. D S MATHURIA, R S MEENA, R MEHTA, K K MISTRI, A PANDEY ...

  20. Resonances in a periodically driven bosonic system

    Science.gov (United States)

    Quelle, Anton; Smith, Cristiane Morais

    2017-11-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.

  1. Noise-driven phenomena in hysteretic systems

    CERN Document Server

    Dimian, Mihai

    2014-01-01

    Noise-Driven Phenomena in Hysteretic Systems provides a general approach to nonlinear systems with hysteresis driven by noisy inputs, which leads to a unitary framework for the analysis of various stochastic aspects of hysteresis. This book includes integral, differential and algebraic models that are used to describe scalar and vector hysteretic nonlinearities originating from various areas of science and engineering. The universality of the authors approach is also reflected by the diversity of the models used to portray the input noise, from the classical Gaussian white noise to its impulsive forms, often encountered in economics and biological systems, and pink noise, ubiquitous in multi-stable electronic systems. The book is accompanied by HysterSoft© - a robust simulation environment designed to perform complex hysteresis modeling – that can be used by the reader to reproduce many of the results presented in the book as well as to research both disruptive and constructive effects of noise in hysteret...

  2. The MedAustron Accelerator Control System

    CERN Document Server

    Gutleber, J; Marchhart, M; Torcato de Matos, C; Dedic, J; Moser, R

    2011-01-01

    This paper presents the architecture and design of the MedAustron accelerator control system. This ion therapy and research facility is currently under construction in Wr. Neustadt, Austria. The accelerator and its control system are designed at CERN. This class of machine is characterized by rich sets of configuration data, real-time reconfiguration needs and high stability requirements. The machine is operated according to a pulse-to-pulse modulation scheme. Each beam cycle is described in terms of ion type, energy, beam dimensions, intensity and spill length. The control system is based on a multi-tier architecture with the aim to achieve a clear separation between front-end devices and their controllers. In-house developments cover a main timing system, a light-weight layer to standardize operation and communication of front-end controllers, fast and slow control of power converters and a procedure programming framework for automating high-level control and data analysis tasks.

  3. Induction accelerators for the phase rotator system

    Energy Technology Data Exchange (ETDEWEB)

    Reginato, Lou; Yu, Simon; Vanecek, Dave

    2001-07-30

    The principle of magnetic induction has been applied to the acceleration of high current beams in betatrons and a variety of induction accelerators. The linear induction accelerator (LIA) consists of a simple nonresonant structure where the drive voltage is applied to an axially symmetric gap that encloses a toroidal ferromagnetic material. The change in flux in the magnetic core induces an axial electric field that provides particle acceleration. This simple nonresonant (low Q) structure acts as a single turn transformer that can accelerate from hundreds of amperes to tens of kiloamperes, basically only limited by the drive impedance. The LIA is typically a low gradient structure that can provide acceleration fields of varying shapes and time durations from tens of nanoseconds to several microseconds. The efficiency of the LIA depends on the beam current and can exceed 50% if the beam current exceeds the magnetization current required by the ferromagnetic material. The acceleration voltage available is simply given by the expression V=A dB/dt. Hence, for a given cross section of material, the beam pulse duration influences the energy gain. Furthermore, a premium is put on minimizing the diameter, which impacts the total weight or cost of the magnetic material. The diameter doubly impacts the cost of the LIA since the power (cost) to drive the cores is proportional to the volume as well. The waveform requirements during the beam pulse makes it necessary to make provisions in the pulsing system to maintain the desired dB/dt during the useful part of the acceleration cycle. This is typically done two ways, by using the final stage of the pulse forming network (PFN) and by the pulse compensation network usually in close proximity of the acceleration cell. The choice of magnetic materials will be made by testing various materials both ferromagnetic and ferrimagnetic. These materials will include the nickel-iron, silicon steel amorphous and various types of ferrites not

  4. FPGA-accelerated simulation of computer systems

    CERN Document Server

    Angepat, Hari; Chung, Eric S; Hoe, James C; Chung, Eric S

    2014-01-01

    To date, the most common form of simulators of computer systems are software-based running on standard computers. One promising approach to improve simulation performance is to apply hardware, specifically reconfigurable hardware in the form of field programmable gate arrays (FPGAs). This manuscript describes various approaches of using FPGAs to accelerate software-implemented simulation of computer systems and selected simulators that incorporate those techniques. More precisely, we describe a simulation architecture taxonomy that incorporates a simulation architecture specifically designed f

  5. Controllable robust laser driven ion acceleration from near-critical density relativistic self-transparent plasma

    Science.gov (United States)

    Liu, Bin; Meyer-Ter-Vehn, Juergen; Ruhl, Hartmut

    2017-10-01

    We introduce an alternative approach for laser driven self-injected high quality ion acceleration. We call it ion wave breaking acceleration. It operates in relativistic self-transparent plasma for ultra-intense ultra-short laser pulses. Laser propagating in a transparent plasma excites an electron wave as well as an ion wave. When the ion wave breaks, a fraction of ions is self-injected into the positive part of the laser driven wake. This leads to a superior ion pulse with peaked energy spectra; in particular in realistic three-dimensional geometry, the injection occurs localized close to the laser axis producing highly directed bunches. A theory is developed to investigate the ion wave breaking dynamics. Three dimensional Particle-in-Cell simulations with pure-gaussian laser pulses and pre-expanded near-critical density plasma targets have been done to verify the theoretical results. It is shown that hundreds of MeV, easily controllable and manipulable, micron-scale size, highly collimated and quasi-mono-energetic ion beams can be produced by using ultra-intense ultra-short laser pulses with total laser energies less than 10 Joules. Such ion beams may find important applications in tumour therapy. B. Liu acknowledges support from the Alexander von Humboldt Foundation. B. Liu and H. Ruhl acknowledge supports from the Gauss Centre for Supercomputing (GCS), and the Cluster-of-Excellence Munich Centre for Advanced Photonics (MAP).

  6. Gadd45a deficiency accelerates BCR-ABL driven chronic myelogenous leukemia

    Science.gov (United States)

    Maifrede, Silvia; Skorski, Tomasz; Bhatia, Ravi; Hoffman, Barbara; Liebermann, Dan A.

    2017-01-01

    The Gadd45a stress sensor gene is a member in the Gadd45 family of genes that includes Gadd45b & Gadd45g. To investigate the effect of GADD45A in the development of CML, syngeneic wild type lethally irradiated mice were reconstituted with either wild type or Gadd45a null myeloid progenitors transduced with a retroviral vector expressing the 210-kD BCR-ABL fusion oncoprotein. Loss of Gadd45a was observed to accelerate BCR-ABL driven CML resulting in the development of a more aggressive disease, a significantly shortened median mice survival time, and increased BCR-ABL expressing leukemic stem/progenitor cells (GFP+Lin- cKit+Sca+). GADD45A deficient progenitors expressing BCR-ABL exhibited increased proliferation and decreased apoptosis relative to WT counterparts, which was associated with enhanced PI3K-AKT-mTOR-4E-BP1 signaling, upregulation of p30C/EBPa expression, and hyper-activation of p38 and Stat5. Furthermore, Gadd45a expression in samples obtained from CML patients was upregulated in more indolent chronic phase CML samples and down regulated in aggressive accelerated phase CML and blast crisis CML. These results provide novel evidence that Gadd45a functions as a suppressor of BCR/ABL driven leukemia and may provide a unique prognostic marker of CML progression. PMID:28086219

  7. Beam transient analyses of Accelerator Driven Subcritical Reactors based on neutron transport method

    Energy Technology Data Exchange (ETDEWEB)

    He, Mingtao; Wu, Hongchun [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China); Zheng, Youqi, E-mail: yqzheng@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China); Wang, Kunpeng [Nuclear and Radiation Safety Center, PO Box 8088, Beijing 100082 (China); Li, Xunzhao; Zhou, Shengcheng [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi (China)

    2015-12-15

    Highlights: • A transport-based kinetics code for Accelerator Driven Subcritical Reactors is developed. • The performance of different kinetics methods adapted to the ADSR is investigated. • The impacts of neutronic parameters deteriorating with fuel depletion are investigated. - Abstract: The Accelerator Driven Subcritical Reactor (ADSR) is almost external source dominated since there is no additional reactivity control mechanism in most designs. This paper focuses on beam-induced transients with an in-house developed dynamic analysis code. The performance of different kinetics methods adapted to the ADSR is investigated, including the point kinetics approximation and space–time kinetics methods. Then, the transient responds of beam trip and beam overpower are calculated and analyzed for an ADSR design dedicated for minor actinides transmutation. The impacts of some safety-related neutronics parameters deteriorating with fuel depletion are also investigated. The results show that the power distribution varying with burnup leads to large differences in temperature responds during transients, while the impacts of kinetic parameters and feedback coefficients are not very obvious. Classification: Core physic.

  8. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    CERN Document Server

    Assmann, R; Bohl, T; Bracco, C; Buttenschön, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Öz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tückmantel, T; Vieira, J; Vincke, H; Wing, M; Xia G , G

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN { the AWAKE experiment { has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  9. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    CERN Document Server

    Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia, G

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  10. Increased p53 activity does not accelerate telomere-driven ageing

    Science.gov (United States)

    García-Cao, Isabel; García-Cao, Marta; Tomás-Loba, Antonia; Martin-Caballero, Juan; Flores, Juana M; Klatt, Peter; Blasco, María A; Serrano, Manuel

    2006-01-01

    There is a great interest in determining the impact of p53 on ageing and, for this, it is important to discriminate among the known causes of ageing. Telomere loss is a well-established source of age-associated damage, which by itself can recapitulate ageing in mouse models. Here, we have used a genetic approach to interrogate whether p53 contributes to the elimination of telomere-damaged cells and its impact on telomere-driven ageing. We have generated compound mice carrying three functional copies of the p53 gene (super-p53) in a telomerase-deficient background and we have measured the presence of chromosomal abnormalities and DNA damage in several tissues. We have found that the in vivo load of telomere-derived chromosomal damage is significantly decreased in super-p53/telomerase-null mice compared with normal-p53/telomerase-null mice. Interestingly, the presence of extra p53 activity neither accelerates nor delays telomere-driven ageing. From these observations, we conclude that p53 has an active role in eliminating telomere-damaged cells, and we exclude the possibility of an age-promoting effect of p53 on telomere-driven ageing. PMID:16582880

  11. Gravity-Driven Acceleration and Kinetic Inflation in Noncommutative Brans-Dicke Setting

    Science.gov (United States)

    Rasouli, S. M. M.; Vargas Moniz, Paulo

    By assuming the spatially flat FLRW line-element and employing the Hamiltonian formalism, a noncommutative (NC) setting of the Brans-Dicke (BD) theory is introduced. We investigate gravity-driven acceleration and kinetic inflation in this NC BD cosmology. Despite to the commutative case, in which both the scale factor and BD scalar field are obtained in power-law forms (in terms of the cosmic time), in our herein NC model, we see that the power-law scalar factor is multiplied by a dynamical exponential warp factor. This warp factor depends on not only the noncommutative parameter but also the momentum conjugate associated to the BD scalar field. For very small values of this parameter, we obtain an appropriate inflationary solution, which can overcome problems within standard BD cosmology in a more efficient manner. Moreover, we see that a graceful exit from an early acceleration epoch towards a decelerating radiation epoch is provided. For late times, due to the presence of the NC parameter, we obtain a zero acceleration epoch, which can be interpreted as the coarse-grained explanation.

  12. THz cavities and injectors for compact electron acceleration using laser-driven THz sources

    Directory of Open Access Journals (Sweden)

    Moein Fakhari

    2017-04-01

    Full Text Available We present a design methodology for developing ultrasmall electron injectors and accelerators based on cascaded cavities excited by short multicycle THz pulses obtained from laser-driven THz generation schemes. Based on the developed concept for optimal coupling of the THz pulse, a THz electron injector and two accelerating stages are designed. The designed electron gun consists of a four cell cavity operating at 300 GHz and a door-knob waveguide to coaxial coupler. Moreover, special designs are proposed to mitigate the problem of thermal heat flow and induced mechanical stress to achieve a stable device. We demonstrated a gun based on cascaded cavities that is powered by only 1.1 mJ of THz energy in 300 cycles to accelerate electron bunches up to 250 keV. An additional two linac sections can be added with five and four cell cavities both operating at 300 GHz boosting the bunch energy up to 1.2 MeV using a 4-mJ THz pulse.

  13. Demonstration of electron acceleration in a laser-driven dielectric microstructure

    Science.gov (United States)

    Peralta, E. A.; Soong, K.; England, R. J.; Colby, E. R.; Wu, Z.; Montazeri, B.; McGuinness, C.; McNeur, J.; Leedle, K. J.; Walz, D.; Sozer, E. B.; Cowan, B.; Schwartz, B.; Travish, G.; Byer, R. L.

    2013-11-01

    The enormous size and cost of current state-of-the-art accelerators based on conventional radio-frequency technology has spawned great interest in the development of new acceleration concepts that are more compact and economical. Micro-fabricated dielectric laser accelerators (DLAs) are an attractive approach, because such dielectric microstructures can support accelerating fields one to two orders of magnitude higher than can radio-frequency cavity-based accelerators. DLAs use commercial lasers as a power source, which are smaller and less expensive than the radio-frequency klystrons that power today's accelerators. In addition, DLAs are fabricated via low-cost, lithographic techniques that can be used for mass production. However, despite several DLA structures having been proposed recently, no successful demonstration of acceleration in these structures has so far been shown. Here we report high-gradient (beyond 250MeVm-1) acceleration of electrons in a DLA. Relativistic (60-MeV) electrons are energy-modulated over 563+/-104 optical periods of a fused silica grating structure, powered by a 800-nm-wavelength mode-locked Ti:sapphire laser. The observed results are in agreement with analytical models and electrodynamic simulations. By comparison, conventional modern linear accelerators operate at gradients of 10-30MeVm-1, and the first linear radio-frequency cavity accelerator was ten radio-frequency periods (one metre) long with a gradient of approximately 1.6MeVm-1 (ref. 5). Our results set the stage for the development of future multi-staged DLA devices composed of integrated on-chip systems. This would enable compact table-top accelerators on the MeV-GeV (106-109eV) scale for security scanners and medical therapy, university-scale X-ray light sources for biological and materials research, and portable medical imaging devices, and would substantially reduce the size and cost of a future collider on the multi-TeV (1012eV) scale.

  14. ORNL 25 MV tandem accelerator control system

    Energy Technology Data Exchange (ETDEWEB)

    Juras, R.C.; Biggerstaff, J.A.; Hoglund, D.E.

    1986-06-01

    The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system: a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. The experience of nearly seven years of control system operation and improvements is discussed.

  15. ORNL 25 MV tandem accelerator control system

    Energy Technology Data Exchange (ETDEWEB)

    Juras, R.C.; Biggerstaff, J.A.; Hoglund, D.E.

    1985-01-01

    The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system, a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. Nearly seven years of control system operation and improvements will be discussed.

  16. Accelerated degradation of silicon metallization systems

    Science.gov (United States)

    Lathrop, J. W.

    1983-11-01

    Clemson University has been engaged for the past five years in a program to determine the reliability attributes of solar cells by means of accelerated test procedures. The cells are electrically measured and visually inspected and then subjected for a period of time to stress in excess of that normally encountered in use, and then they are reinspected. Changes are noted and the process repeated. This testing has thus far involved 23 different unencapsulated cell types from 12 different manufacturers, and 10 different encapsulated cell types from 9 different manufacturers. Reliability attributes of metallization systems can be classified as major or minor, depending on the severity of the effects observed. As a result of the accelerated testing conducted under the Clemson program, major effects have been observed related to contact resistance and to mechanical adherence and solderability. This paper does not attempt a generalized survey of accelerated test results, but rather concentrates on one particular attribute of metallization that has been observed to cause electrical degradation - increased contact resistance due to Schottky barrier formation. In this example basic semiconductor theory was able to provide an understanding of the electrical effects observed during accelerated stress testing.

  17. Strengthening Health Systems to Accelerate Achievement of ...

    African Journals Online (AJOL)

    Strengthening Health Systems to Accelerate Achievement of Millennium Development Goals 4 and 5: A Case Study of Ketu South and Keta Municipalities in Ghana. ... de santé pour accélérer la réalisation des OMD 4 et 5 dans la région de la Volta au Ghana, avec un accent particulier sur les municipalités Ketu Sud et Keta.

  18. Strengthening Health Systems to Accelerate Achievement of ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    This study aims to determine means of strengthening the health system to accelerate achievement of MDGs 4 and 5 in the Volta. Region of Ghana ... région de la Volta au Ghana, avec un accent particulier sur les municipalités Ketu Sud et Keta. ... La mortalité maternelle et infantile élevée est un problème crucial au Ghana.

  19. A Data-driven Analytic Model for Proton Acceleration by Large-scale Solar Coronal Shocks

    Science.gov (United States)

    Kozarev, Kamen A.; Schwadron, Nathan A.

    2016-11-01

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona, using remote observations from the Solar Dynamics Observatory’s Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating the efficiency of charged particle acceleration within the theoretical framework of diffusive shock acceleration (DSA). These parameters include the time-dependent front size, speed, and strength, as well as the upstream coronal magnetic field orientations with respect to the front’s surface normal direction. Here we present an analytical particle acceleration model, specifically developed to incorporate the coronal shock/compressive front properties described above, derived from remote observations. We verify the model’s performance through a grid of idealized case runs using input parameters typical for large-scale coronal shocks, and demonstrate that the results approach the expected DSA steady-state behavior. We then apply the model to the event of 2011 May 11 using the OCBF time-dependent parameters derived by Kozarev et al. We find that the compressive front likely produced energetic particles as low as 1.3 solar radii in the corona. Comparing the modeled and observed fluences near Earth, we also find that the bulk of the acceleration during this event must have occurred above 1.5 solar radii. With this study we have taken a first step in using direct observations of shocks and compressions in the innermost corona to predict the onsets and intensities of solar energetic particle events.

  20. Optimizing density down-ramp injection for beam-driven plasma wakefield accelerators

    Science.gov (United States)

    Martinez de la Ossa, A.; Hu, Z.; Streeter, M. J. V.; Mehrling, T. J.; Kononenko, O.; Sheeran, B.; Osterhoff, J.

    2017-09-01

    Density down-ramp (DDR) injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement the theoretical principles of the method and employ particle-in-cell (PIC) simulations in order to determine constrains on the geometry of the density ramp and the current of the drive beam, regarding the applicability of DDR injection. Furthermore, PIC simulations are utilized to find optimized conditions for the production of high-quality beams. We find and explain the intriguing result that the injection of an increased charge by means of a steepened ramp favors the generation of beams with lower emittance. Exploiting this fact enables the production of beams with high charge (˜140 pC ), low normalized emittance (˜200 nm ) and low uncorrelated energy spread (0.3%) in sufficiently steep ramps even for drive beams with moderate peak current (˜2.5 kA ).

  1. Net Shape Manufacturing of Accelerator Components by High Pressure Combustion Driven Powder Compaction

    CERN Document Server

    Nagarathnam, Karthik

    2005-01-01

    We present an overview of the net shape and cost-effective manufacturing aspects of high density accelerator (normal and superconducting) components (e.g., NLC Copper disks) and materials behavior of copper, stainless steel, refractory materials (W, Mo and TZM), niobium and SiC by innovative high pressure Combustion Driven Compaction (CDC) technology. Some of the unique process advantages include high densities, net-shaping, improved surface finish/quality, suitability for simple/complex geometries, synthesis of single as well as multilayered materials, milliseconds of compaction process time, little or no post-machining, and process flexibility. Some of the key results of CDC fabricated sample geometries, process optimization, sintering responses and structure/property characteristics such as physical properties, surface roughness/quality, electrical conductivity, select microstructures and mechanical properties will be presented. Anticipated applications of CDC compaction include advanced x-ray targets, vac...

  2. New shielding material development for compact accelerator-driven neutron source

    Directory of Open Access Journals (Sweden)

    Guang Hu

    2017-04-01

    Full Text Available The Compact Accelerator-driven Neutron Source (CANS, especially the transportable neutron source is longing for high effectiveness shielding material. For this reason, new shielding material is researched in this investigation. The component of shielding material is designed and many samples are manufactured. Then the attenuation detection experiments were carried out. In the detections, the dead time of the detector appeases when the proton beam is too strong. To grasp the linear range and nonlinear range of the detector, two currents of proton are employed in Pb attenuation detections. The transmission ratio of new shielding material, polyethylene (PE, PE + Pb, BPE + Pb is detected under suitable current of proton. Since the results of experimental neutrons and γ-rays appear as together, the MCNP and PHITS simulations are applied to assisting the analysis. The new shielding material could reduce of the weight and volume compared with BPE + Pb and PE + Pb.

  3. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  4. Lasers As Particle Accelerators In Medicine: From Laser-Driven Protons To Imaging With Thomson Sources

    Science.gov (United States)

    Pogorelsky, I. V.; Babzien, M.; Polyanskiy, M. N.; Yakimenko, V.; Dover, N. P.; Palmer, C. A. J.; Najmudin, Z.; Shkolnikov, P.; Williams, O.; Rosenzweig, J.; Oliva, P.; Carpinelli, M.; Golosio, B.; Delogu, P.; Stefanini, A.; Endrizzi, M.

    2011-06-01

    We report our recent progress using a high-power, picosecond CO2 laser for Thomson scattering and ion acceleration experiments. These experiments capitalize on certain advantages of long-wavelength CO2 lasers, such as their high number of photons per energy unit and beneficial wavelength- scaling of the electrons' ponderomotive energy and critical plasma frequency. High X-ray fluxes produced in the interactions of the counter-propagating laser- and electron-beams for obtaining single-shot, high-contrast images of biological objects. The laser, focused on a hydrogen jet, generated a monoenergetic proton beam via the radiation-pressure mechanism. The energy of protons produced by this method scales linearly with the laser's intensity. We present a plan for scaling the process into the range of 100-MeV proton energy via upgrading the CO2 laser. This development will enable an advance to the laser-driven proton cancer therapy.

  5. Shock creation and particle acceleration driven by plasma expansion into a rarefied medium

    CERN Document Server

    Sarri, G; Dieckmann, M E; Borghesi, M

    2010-01-01

    The expansion of a dense plasma through a more rarefied ionised medium is a phenomenon of interest in various physics environments ranging from astrophysics to high energy density laser- matter laboratory experiments. Here this situation is modeled via a 1D Particle-In-Cell simulation; a jump in the plasma density of a factor of 100 is introduced in the middle of an otherwise equally dense electron-proton plasma with an uniform proton and electron temperature of 10eV and 1keV respectively. The diffusion of the dense plasma, through the rarified one, triggers the onset of different nonlinear phenomena such as a strong ion-acoustic shock wave and a rarefaction wave. Secondary structures are detected, some of which are driven by a drift instability of the rarefaction wave. Efficient proton acceleration occurs ahead of the shock, bringing the maximum proton velocity up to 60 times the initial ion thermal speed.

  6. General theory eh ondulyatornyh induction acceleration systems

    Directory of Open Access Journals (Sweden)

    В.В. Куліш

    2006-01-01

    Full Text Available  Universal theoretical model within which it is possible quantitative description of ЕН-accelerators and similar devices on their basis is built (ЕН-systems. Description of such universal model is offered to realize within the theory of hierarhial ossilations and waves. For solution of nonlinear tasks of theory of the ЕН-systems is offered to use the hierarchical versions of method of Bogolubov, method of averaged equation for the current density and method of hierarchical transformation of coordinates.

  7. Towards a novel laser-driven method of exotic nuclei extraction−acceleration for fundamental physics and technology

    Energy Technology Data Exchange (ETDEWEB)

    Nishiuchi, M., E-mail: sergei@jaea.go.jp; Sakaki, H.; Esirkepov, T. Zh. [Japan Atomic Energy Agency, Kansai Photon Science Institute (Japan); Nishio, K. [Japan Atomic Energy Agency, Advanced Science Research Center (Japan); Pikuz, T. A.; Faenov, A. Ya. [Japan Atomic Energy Agency, Kansai Photon Science Institute (Japan); Skobelev, I. Yu. [Russian Academy of Sciences, Joint Institute for High Temperature (Russian Federation); Orlandi, R. [Japan Atomic Energy Agency, Advanced Science Research Center (Japan); Pirozhkov, A. S.; Sagisaka, A.; Ogura, K.; Kanasaki, M.; Kiriyama, H.; Fukuda, Y. [Japan Atomic Energy Agency, Kansai Photon Science Institute (Japan); Koura, H. [Japan Atomic Energy Agency, Advanced Science Research Center (Japan); Kando, M. [Japan Atomic Energy Agency, Kansai Photon Science Institute (Japan); Yamauchi, T. [Graduate School of Maritime Sciences (Japan); Watanabe, Y. [Kyushu University, Interdisciplinary Graduate School of Engineering Sciences (Japan); Bulanov, S. V., E-mail: svbulanov@gmail.com; Kondo, K. [Japan Atomic Energy Agency, Kansai Photon Science Institute (Japan); and others

    2016-04-15

    A combination of a petawatt laser and nuclear physics techniques can crucially facilitate the measurement of exotic nuclei properties. With numerical simulations and laser-driven experiments we show prospects for the Laser-driven Exotic Nuclei extraction–acceleration method proposed in [M. Nishiuchi et al., Phys, Plasmas 22, 033107 (2015)]: a femtosecond petawatt laser, irradiating a target bombarded by an external ion beam, extracts from the target and accelerates to few GeV highly charged short-lived heavy exotic nuclei created in the target via nuclear reactions.

  8. Analytic approach to nonlinear hydrodynamic instabilities driven by time-dependent accelerations

    Energy Technology Data Exchange (ETDEWEB)

    Mikaelian, K O

    2009-09-28

    We extend our earlier model for Rayleigh-Taylor and Richtmyer-Meshkov instabilities to the more general class of hydrodynamic instabilities driven by a time-dependent acceleration g(t) . Explicit analytic solutions for linear as well as nonlinear amplitudes are obtained for several g(t)'s by solving a Schroedinger-like equation d{sup 2}{eta}/dt{sup 2} - g(t)kA{eta} = 0 where A is the Atwood number and k is the wavenumber of the perturbation amplitude {eta}(t). In our model a simple transformation k {yields} k{sub L} and A {yields} A{sub L} connects the linear to the nonlinear amplitudes: {eta}{sup nonlinear} (k,A) {approx} (1/k{sub L})ln{eta}{sup linear} (k{sub L}, A{sub L}). The model is found to be in very good agreement with direct numerical simulations. Bubble amplitudes for a variety of accelerations are seen to scale with s defined by s = {integral} {radical}g(t)dt, while spike amplitudes prefer scaling with displacement {Delta}x = {integral}[{integral}g(t)dt]dt.

  9. Statistical mechanics of driven diffusive systems

    CERN Document Server

    Schmittmann, B

    1995-01-01

    Far-from-equilibrium phenomena, while abundant in nature, are not nearly as well understood as their equilibrium counterparts. On the theoretical side, progress is slowed by the lack of a simple framework, such as the Boltzmann-Gbbs paradigm in the case of equilibrium thermodynamics. On the experimental side, the enormous structural complexity of real systems poses serious obstacles to comprehension. Similar difficulties have been overcome in equilibrium statistical mechanics by focusing on model systems. Even if they seem too simplistic for known physical systems, models give us considerable insight, provided they capture the essential physics. They serve as important theoretical testing grounds where the relationship between the generic physical behavior and the key ingredients of a successful theory can be identified and understood in detail. Within the vast realm of non-equilibrium physics, driven diffusive systems form a subset with particularly interesting properties. As a prototype model for these syst...

  10. Quasi-monoenergetic ion beam acceleration by laser-driven shock and solitary waves in near-critical plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W. L.; Qiao, B., E-mail: bqiao@pku.edu.cn; Huang, T. W.; Shen, X. F.; You, W. Y. [Center for Applied Physics and Technology, HEDPS, and State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006 (China); Yan, X. Q. [Center for Applied Physics and Technology, HEDPS, and State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Wu, S. Z. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Zhou, C. T.; He, X. T. [Center for Applied Physics and Technology, HEDPS, and State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

    2016-07-15

    Ion acceleration in near-critical plasmas driven by intense laser pulses is investigated theoretically and numerically. A theoretical model has been given for clarification of the ion acceleration dynamics in relation to different laser and target parameters. Two distinct regimes have been identified, where ions are accelerated by, respectively, the laser-induced shock wave in the weakly driven regime (comparatively low laser intensity) and the nonlinear solitary wave in the strongly driven regime (comparatively high laser intensity). Two-dimensional particle-in-cell simulations show that quasi-monoenergetic proton beams with a peak energy of 94.6 MeV and an energy spread 15.8% are obtained by intense laser pulses at intensity I{sub 0} = 3 × 10{sup 20 }W/cm{sup 2} and pulse duration τ = 0.5 ps in the strongly driven regime, which is more advantageous than that got in the weakly driven regime. In addition, 233 MeV proton beams with narrow spread can be produced by extending τ to 1.0 ps in the strongly driven regime.

  11. Antigen-driven bystander effect accelerates epicutaneous sensitization with a new protein allergen

    Directory of Open Access Journals (Sweden)

    Yu Jhang-Sian

    2009-03-01

    Full Text Available Abstract Exposure to protein allergen epicutaneously, inducing a Th2-dominant immune response, sensitizes the host to the development of atopic disease. Antigen-driven bystander effect demonstrates that polarized T cells could instruct naïve T cells to differentiate into T cells with similar phenotype. In this study, we aimed to determine the contribution of antigen-driven bystander effect on epicutaneous sensitization with a newly introduced protein allergen. BALB/c mice were immunized intraperitoneally with BSA emulsified in alum, known to induce a Th2 response, three weeks before given BSA and OVA epicutaneously. Lymph node cells from these mice restimulated with OVA secreted higher levels IL-4, IL-5 and IL-13 as compared with cells from mice without BSA immunization. In addition, BALB/c mice immunized subcutaneously with BSA emulsified in complete Freund's adjuvant, known to induce a Th1-predominant response, also induced higher Th1 as well as Th2 cytokine response when restimulated with OVA as compared with mice without immunization. We demonstrated that subcutaneous immunization with BSA in CFA induced Th2 as well as Th1 response. The threshold of epicutaneous sensitization to OVA was also reduced, possibly due to increased expressions of IL-4 and IL-10 in the draining lymph nodes during the early phase of sensitization. In conclusion, antigen-driven bystander effect, whether it is of Th1- or Th2-predominant nature, can accelerate epicutaneous sensitization by a newly introduced protein allergen. These results provide a possible explanation for mono- to poly-sensitization spread commonly observed in atopic children.

  12. Superconducting linear accelerator system for NSC

    Indian Academy of Sciences (India)

    This paper reports the construction of a superconducting linear accelerator as a booster to the 15 UD Pelletron accelerator at Nuclear Science Centre, New Delhi. The LINAC will use superconducting niobium quarter wave resonators as the accelerating element. Construction of the linear accelerator has progressed ...

  13. Model Driven Laboratory Information Management Systems

    Science.gov (United States)

    Li, Hao; Gennari, John H.; Brinkley, James F.

    2006-01-01

    Scientists in small research labs need more robust tools than spreadsheets to manage their data. However, no suitable laboratory information management systems (LIMS) are readily available; they are either too costly or too complex. We have therefore developed Seedpod, a model driven LIMS that allows users to create an integrated model of a LIMS without programming. Seedpod then automatically produces a relational database from the model, and dynamically generates a web-based graphical user interface. Our goal is to make LIMS easier to use by decreasing development time and cost, thereby allowing researchers to focus on producing and collecting data. PMID:17238388

  14. Stochastic driven systems far from equilibrium

    Science.gov (United States)

    Kim, Kyung Hyuk

    We study the dynamics and steady states of two systems far from equilibrium: a 1-D driven lattice gas and a driven Brownian particle with inertia. (1) We investigate the dynamical scaling behavior of a 1-D driven lattice gas model with two species of particles hopping in opposite directions. We confirm numerically that the dynamic exponent is equal to z = 1.5. We show analytically that a quasi-particle representation relates all phase points to a special phase line directly related to the single-species asymmetric simple exclusion process. Quasi-particle two-point correlations decay exponentially, and in such a manner that quasi-particles of opposite charge dynamically screen each other with a special balance. The balance encompasses all over the phase space. These results indicate that the model belongs to the Kardar-Parisi-Zhang (KPZ) universality class. (2) We investigate the non-equilibrium thermodynamics of a Brownian particle with inertia under feedback control of its inertia. We find such open systems can act as a molecular refrigerator due to an entropy pumping mechanism. We extend the fluctuation theorems to the refrigerator. The entropy pumping modifies both the Jarzynski equality and the fluctuation theorems. We discover that the entropy pumping has a dual role of work and heat. We also investigate the thermodynamics of the particle under a hydrodynamic interaction described by a Langevin equation with a multiplicative noise. The Stratonovich stochastic integration prescription involved in the definition of heat is shown to be the unique physical choice.

  15. Reliable timing systems for computer controlled accelerators

    Science.gov (United States)

    Knott, Jürgen; Nettleton, Robert

    1986-06-01

    Over the past decade the use of computers has set new standards for control systems of accelerators with ever increasing complexity coupled with stringent reliability criteria. In fact, with very slow cycling machines or storage rings any erratic operation or timing pulse will cause the loss of precious particles and waste hours of time and effort of preparation. Thus, for the CERN linac and LEAR (Low Energy Antiproton Ring) timing system reliability becomes a crucial factor in the sense that all components must operate practically without fault for very long periods compared to the effective machine cycle. This has been achieved by careful selection of components and design well below thermal and electrical limits, using error detection and correction where possible, as well as developing "safe" decoding techniques for serial data trains. Further, consistent structuring had to be applied in order to obtain simple and flexible modular configurations with very few components on critical paths and to minimize the exchange of information to synchronize accelerators. In addition, this structuring allows the development of efficient strategies for on-line and off-line fault diagnostics. As a result, the timing system for Linac 2 has, so far, been operating without fault for three years, the one for LEAR more than one year since its final debugging.

  16. Climate-driven vertical acceleration of Icelandic crust measured by continuous GPS geodesy

    KAUST Repository

    Compton, Kathleen

    2015-02-06

    © 2015 The Authors. Earth\\'s present-day response to enhanced glacial melting resulting from climate change can be measured using Global Positioning System (GPS) technology. We present data from 62 continuously operating GPS instruments in Iceland. Statistically significant upward velocity and accelerations are recorded at 27 GPS stations, predominantly located in the Central Highlands region of Iceland, where present-day thinning of the Iceland ice caps results in velocities of more than 30mm/yr and uplift accelerations of 1-2mm/yr2. We use our acceleration estimates to back calculate to a time of zero velocity, which coincides with the initiation of ice loss in Iceland from ice mass balance calculations and Arctic warming trends. We show, through a simple inversion, a direct relationship between ice mass balance measurements and vertical position and show that accelerated unloading is required to reproduce uplift observations for a simple elastic layer over viscoelastic half-space model.

  17. Data-Driven Control of Refrigeration System

    DEFF Research Database (Denmark)

    Vinther, Kasper

    Refrigeration is used in a wide range of applications, e.g., for storage of food at low temperatures to prolong shelf life and in air conditioning for occupancy comfort. The main focus of this thesis is control of supermarket refrigeration systems. This market is very competitive and it is import......Refrigeration is used in a wide range of applications, e.g., for storage of food at low temperatures to prolong shelf life and in air conditioning for occupancy comfort. The main focus of this thesis is control of supermarket refrigeration systems. This market is very competitive...... conditions make optimal tuning of controllers a difficult and time consuming task. These are also some of the challenges which make advanced model-based control difficult, and a model-based controller will often be tailored to a specific system. The focus in this thesis is therefore instead on development...... of data-driven control strategies with a higher plug and play potential. One of the main control challenges in refrigeration systems is proper control of superheat for efficient and safe operation of the system. This task can be performed by an electronic expansion valve and requires two sensors, which...

  18. STUDIES OF A FREE ELECTRON LASER DRIVEN BY A LASER-PLASMA ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.; Schroeder, C.; Fawley, W.

    2008-01-01

    A free electron laser (FEL) uses an undulator, a set of alternating magnets producing a periodic magnetic fi eld, to stimulate emission of coherent radiation from a relativistic electron beam. The Lasers, Optical Accelerator Systems Integrated Studies (LOASIS) group at Lawrence Berkeley National Laboratory (LBNL) will use an innovative laserplasma wakefi eld accelerator to produce an electron beam to drive a proposed FEL. In order to optimize the FEL performance, the dependence on electron beam and undulator parameters must be understood. Numerical modeling of the FEL using the simulation code GINGER predicts the experimental results for given input parameters. Among the parameters studied were electron beam energy spread, emittance, and mismatch with the undulator focusing. Vacuum-chamber wakefi elds were also simulated to study their effect on FEL performance. Energy spread was found to be the most infl uential factor, with output FEL radiation power sharply decreasing for relative energy spreads greater than 0.33%. Vacuum chamber wakefi elds and beam mismatch had little effect on the simulated LOASIS FEL at the currents considered. This study concludes that continued improvement of the laser-plasma wakefi eld accelerator electron beam will allow the LOASIS FEL to operate in an optimal regime, producing high-quality XUV and x-ray pulses.

  19. Optimizing density down-ramp injection for beam-driven plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    A. Martinez de la Ossa

    2017-09-01

    Full Text Available Density down-ramp (DDR injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement the theoretical principles of the method and employ particle-in-cell (PIC simulations in order to determine constrains on the geometry of the density ramp and the current of the drive beam, regarding the applicability of DDR injection. Furthermore, PIC simulations are utilized to find optimized conditions for the production of high-quality beams. We find and explain the intriguing result that the injection of an increased charge by means of a steepened ramp favors the generation of beams with lower emittance. Exploiting this fact enables the production of beams with high charge (∼140  pC, low normalized emittance (∼200  nm and low uncorrelated energy spread (0.3% in sufficiently steep ramps even for drive beams with moderate peak current (∼2.5  kA.

  20. Neutron data for accelerator-driven transmutation technologies. Annual Report 2003/2004

    Energy Technology Data Exchange (ETDEWEB)

    Blomgren, J.; Hildebrand, A.; Nilsson, L.; Mermod, P.; Olsson, N.; Pomp, S.; Oesterlund, M. [Uppsala Univ. (Sweden). Dept. for Neutron Research

    2004-08-01

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Dept. of Neutron Research, Uppsala univ. The activities of the group are directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from hydrogen at 96 MeV. The results corroborate the normalization of previously obtained data at TSL, which have been under debate. This is of importance since this reaction serves as reference for many other measurements. Compelling evidence of the existence of three-body forces in nuclei has been obtained. Within the project, one PhD exam and one licentiate exam has been awarded. One PhD exam and one licentiate exam has been awarded for work closely related to the project. A new neutron beam facility with significantly improved performance has been built and commissioned at TSL.

  1. Nuclear data for accelerator-driven transmutation. Annual report 1998/99

    Energy Technology Data Exchange (ETDEWEB)

    Blomgren, J.; Johansson, C.; Klug, J.; Olsson, N.; Renberg, P.U. [Uppsala Univ. (Sweden). Dept. of Neutron Research. The Svedberg Lab.

    1999-09-01

    The present project, supported as a research task agreement by the Nuclear Power Inspectorate, the Nuclear Fuel and Waste Management Co, Barsebaeck Kraft AB and Vattenfall AB, started according to the plan 1998-07-01. From 1999-01-01 the project also receives support from the Defence Research Institute. The primary objective from the supporting organizations is to promote research and research education of relevance for development of the national competence within nuclear energy. The aim of the project is in short to: promote development of the competence within nuclear physics and nuclear technology by supporting PhD students; push forward the international research front regarding fundamental nuclear data within the presently highlighted research area 'accelerator-driven transmutation'; strengthen the Swedish influence within the mentioned research area by expanding the international contact network; and constitute a basis for Swedish participation in the nuclear data activities at IAEA and OECD/NEA. The project is run by the Department of Neutron Research at Uppsala University, and is utilizing the unique neutron beam facility at the national The Svedberg Laboratory (TSL) at Uppsala University. In this document, we give a status report after the first year (1998-07-01--1999-06-30) of the project.

  2. SPS RF System an Accelerating Cavity

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X.

  3. A table-top x-ray FEL based on a laser wakefield accelerator-undulator system

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, K.; Kawakubo, T.; Nakanishi, H. [National Lab. for High Energy Physics, Ibaraki-ken (Japan)] [and others

    1995-12-31

    Ultrahigh-gradient electron acceleration has been confirmed owing to the laser wakefield acceleration mechanism driven by an intense short laser wakefield acceleration mechanism driven by an intense short laser pulse in an underdense plasma. The laser wakefield acceleration makes it possible to build a compact electron linac capable of producing an ultra-short bunched electron beam. While the accelerator is attributed to longitudinal wakefields, transverse wakefields simultaneously generated by a short laser pulse can serve as a plasma undulator with a very short wavelength equal to a half of the plasma wavelength. We propose a new FEL concept for X-rays based on a laser wakefield accelerator-undulator system driven by intense short laser pulses delivered from table-top terawatt lasers. The system is composed of the accelerator stage and the undulator stage in a table-top size. A low energy electron beam is accelerated an bunched into microbunches due to laser wakefields in the accelerator stage. A micro-bunched beam travelling to the opposite direction of driving laser pulses produces coherent X-ray radiation in the undulator stage. A practical configuration and its analyses are presented.

  4. BIOCONAID System (Bionic Control of Acceleration Induced Dimming). Final Report.

    Science.gov (United States)

    Rogers, Dana B.; And Others

    The system described represents a new technique for enhancing the fidelity of flight simulators during high acceleration maneuvers. This technique forces the simulator pilot into active participation and energy expenditure similar to the aircraft pilot undergoing actual accelerations. The Bionic Control of Acceleration Induced Dimming (BIOCONAID)…

  5. Cache-based memory copy hardware accelerator for multicore systems

    NARCIS (Netherlands)

    Duarte, F.; Wong, S.

    2010-01-01

    In this paper, we present a new architecture of the cache-based memory copy hardware accelerator in a multicore system supporting message passing. The accelerator is able to accelerate memory data movements, in particular memory copies. We perform an analytical analysis based on open-queuing theory

  6. Open Hardware For CERN's Accelerator Control Systems

    CERN Document Server

    van der Bij, E; Ayass, M; Boccardi, A; Cattin, M; Gil Soriano, C; Gousiou, E; Iglesias Gonsálvez, S; Penacoba Fernandez, G; Serrano, J; Voumard, N; Wlostowski, T

    2011-01-01

    The accelerator control systems at CERN will be renovated and many electronics modules will be redesigned as the modules they will replace cannot be bought anymore or use obsolete components. The modules used in the control systems are diverse: analog and digital I/O, level converters and repeaters, serial links and timing modules. Overall around 120 modules are supported that are used in systems such as beam instrumentation, cryogenics and power converters. Only a small percentage of the currently used modules are commercially available, while most of them had been specifically designed at CERN. The new developments are based on VITA and PCI-SIG standards such as FMC (FPGA Mezzanine Card), PCI Express and VME64x using transition modules. As system-on-chip interconnect, the public domain Wishbone specification is used. For the renovation, it is considered imperative to have for each board access to the full hardware design and its firmware so that problems could quickly be resolved by CERN engineers or its ...

  7. Conceptual design for accelerator-driven sodium-cooled sub-critical transmutation reactors using scale laws

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Gu; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates the reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scaled and verified through the methodology in this paper, which is referred to Advanced Liquid Metal Reactor (ALMR). A Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the integrated code system. Integrated Code System (ICS) consists of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target region, the core region, and thermal-hydraulic related regions are analyzed once-through Results of conceptual design are attached in this paper. 5 refs., 4 figs., 1 tab. (Author)

  8. The Control System of CERN Accelerators Vacuum (Current Status and Recent Improvements)

    CERN Document Server

    Gomes, P; Blanchard, S; Boccioli, M; Girardot, G; Vestergard, H; Kopylov, L; Mikheev, M

    2011-01-01

    The vacuum control system of most of the CERN accelerators is based on Siemens PLCs and on PVSS SCADA. After the transition from the LHC commissioning phase to its regular operation, there has been a number of additions and improvements to the vacuum control system. They were driven by new technical requirements and by feedback from the accelerator operators and vacuum specialists. New control functions have been implemented in the PLCs; new tools have been developed for the SCADA, while its ergonomics and navigation have been enhanced.

  9. Proton Acceleration Driven by a Nanosecond Laser from a Cryogenic Thin Solid-Hydrogen Ribbon

    Directory of Open Access Journals (Sweden)

    D. Margarone

    2016-11-01

    Full Text Available A high-power pulsed laser is focused onto a solid-hydrogen target to accelerate forward a collimated stream of protons in the range 0.1–1 MeV, carrying a very high energy of about 30 J (∼5% laser-ion conversion efficiency and extremely large charge of about ∼0.1  mC per laser pulse. This result is achieved for the first time through the combination of a sophisticated target system (H_{2} thin ribbon operating at cryogenic temperature (∼10  K and a very hot H plasma (∼300  keV “hot electron” temperature generated by a subnanosecond laser with an intensity of ∼3×10^{16}  W/cm^{2}. Both the H plasma and the accelerated proton beam are fully characterized by in situ and ex situ diagnostics. Results obtained using the ELISE (experiments on laser interaction with solid hydrogen H_{2} target delivery system at PALS (Prague kJ-class laser facility are presented and discussed along with potential multidisciplinary applications.

  10. Neutron data for accelerator-driven transmutation technologies. Annual Report 2002/2003

    Energy Technology Data Exchange (ETDEWEB)

    Blomgren, J.; Hildebrand, A.; Mermod, P.; Olsson, N.; Pomp, S.; Oesterlund, M. [Uppsala Univ. (Sweden). Dept. for Neutron Research

    2003-08-01

    The project NATT, Neutron data for Accelerator-driven Transmutation Technology, is performed within the nuclear reactions group of the Department for neutron research, Uppsala university. The activities of the group is directed towards experimental studies of nuclear reaction probabilities of importance for various applications, like transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental work is primarily undertaken at the The Svedberg Laboratory (TSL) in Uppsala, where the group has previously developed two world-unique instruments, MEDLEY and SCANDAL. Highlights from the past year: Analysis and documentation has been finalized of previously performed measurements of elastic neutron scattering from carbon and lead at 96 MeV. The precision in the results surpasses all previous data by at least an order of magnitude. These measurements represent the highest energy in neutron scattering where the ground state has been resolved. The results show that all previous theory work has underestimated the probability for neutron scattering at the present energy by 0-30 %. A new method for measurements of absolute probabilities for neutron-induced nuclear reactions with experimental techniques only has been developed. Previously, only two such methods have been known. One student has reached his PhD exam. Two PhD students have been accepted. TSL has decided to build a new neutron beam facility with significantly improved performance for these, and similar, activities. A new instrument for measurements of inelastic neutron scattering has been built, tested and found to meet the specifications. This work has been performed in collaboration with two French research groups from Caen and Nantes. The instrument is intended to be used for a series of experiments during the coming years. Previous work by the group on nuclear data for assessment of electronics reliability has lead to a new industry standard in the USA.

  11. Summary report : working group 5 on 'electron beam-driven plasma and structure based acceleration concepts'.

    Energy Technology Data Exchange (ETDEWEB)

    Conde, M. E.; Katsouleas, T.

    2000-10-19

    The talks presented and the work performed on electron beam-driven accelerators in plasmas and structures are summarized. Highlights of the working group include new experimental results from the E-157 Plasma Wakefield Experiment, the E-150 Plasma Lens Experiment and the Argonne Dielectric Structure Wakefield experiments. The presentations inspired discussion and analysis of three working topics: electron hose instability, ion channel lasers and the plasma afterburner.

  12. a Simulation Study of Beam Driven Instabilities and Solitary Structures in the Auroral Acceleration Region.

    Science.gov (United States)

    Gray, Perry Clayton

    Various problems associated with the model particle distributions and assumptions for auroral acceleration are considered using particle in cell plasma simulation techniques. We have considered the presence and effects of microinstabilities in two regions along auroral field lines. At low altitude, where ions which have been accelerated up out of the ionosphere have a small relative drift (due to mass ratio), the plasma is unstable to an ion two-stream instability. We will show that the heating due to the two-stream instability does not distort the distribution function sufficiently to prevent double layer formation at higher altitude. However, under certain circumstances heating by the oblique two-stream modes is capable of forming conic like distributions. At higher altitude, it has been suggested that the presence of a background ion population may have a significant effect on the formation of weak double layers. We will show that in such a system, a weak beam-plasma instability couples to the acoustic modes in the background ion population seeding the formation of ion phase space holes. Such structures propagate at the acoustic speed of the background ion population, in the direction of the ion beam (opposite of the direction of propagation for such structures in the standart two-species model) and, given a drift of the background electrons, they may develop into double layers. This may explain previous discrepancies between observations of such structures and theoretical prediction of their behavior.

  13. Models of plastic depinning of driven disordered systems

    Indian Academy of Sciences (India)

    pp. 1097–1107. Models of plastic depinning of driven disordered systems. M CRISTINA MARCHETTI. Physics Department, Syracuse University, Syracuse, NY 13244, USA. E-mail: mcm@physics.syr.edu. Abstract. Two classes of models of driven disordered systems that exhibit history- dependent dynamics are discussed.

  14. Planned High-gradient Flat-beam-driven Dielectric Wakefield Experiments at the Fermilab’s Advanced Superconducting Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lemery, Francois [NICADD, DeKalb; Mihalcea, Daniel [NICADD, DeKalb; Piot, Philippe [Fermilab; Zhu, Jun [Mianyang CAEP

    2014-07-01

    In beam driven dielectric wakefield acceleration (DWA), high-gradient short-wavelength accelerating fields are generally achieved by employing dielectric-lined waveguides (DLWs)  with small aperture which constraints the beam sizes. In this paper we investigate the possibility of using a low-energy (50-MeV) flat beams to induce high-gradient wakes in a slab-symmetric DLW. We demonstrate via numerical simulations the possibility to produce axial electric field with peak amplitude close to 0.5 GV/m. Our studies are carried out using the Fermilab's Advanced Superconducting Test Accelerator (ASTA) photoinjector beamline. We finally discuss a possible experiment that could be performed in the ASTA photoinjector and eventually at higher energies.  

  15. Phase-space holes due to electron and ion beams accelerated by a current-driven potential ramp

    Directory of Open Access Journals (Sweden)

    M. V. Goldman

    2003-01-01

    Full Text Available One-dimensional open-boundary simulations have been carried out in a current-carrying plasma seeded with a neutral density depression and with no initial electric field. These simulations show the development of a variety of nonlinear localized electric field structures: double layers (unipolar localized fields, fast electron phase-space holes (bipolar fields moving in the direction of electrons accelerated by the double layer and trains of slow alternating electron and ion phase-space holes (wave-like fields moving in the direction of ions accelerated by the double layer. The principal new result in this paper is to show by means of a linear stability analysis that the slow-moving trains of electron and ion holes are likely to be the result of saturation via trapping of a kinetic-Buneman instability driven by the interaction of accelerated ions with unaccelerated electrons.

  16. The GUINEVERE Project for Accelerator Driven System Physics

    OpenAIRE

    Billebaud, A.; Baeten, P.; Aït Abderrahim, H.; Ban, G.; Baylac, M.; Bergmans, G.; Bondoux, D.; Bouvier, J.; Chabod, S.; De Conto, J.M.; Dessagne, P.; Gaudiot, G; Gautier, J. M.; Granget, G.; Heitz, G

    2009-01-01

    paper 9414; International audience; The GUINEVERE project is part of the EUROTRANS Integrated Project of the 6th EURATOM Framework Programme. It is mainly devoted to ADS on-line reactivity monitoring validation, sub-criticality determination and operational procedures (loading, start-up, shut-down, ...) as a follow-up of the MUSE experiments. The project consists in coupling a fast lead core, set-up in the VENUS reactor at SCK*CEN Mol (B), with a GENEPI neutron source under construction by CN...

  17. Nuclear data requirements for accelerator driven sub-critical systems

    Indian Academy of Sciences (India)

    Qd; 29.25.Dz; 29.25.-t. 1. Introduction. This paper briefly presents the perspective of the author on the nuclear data require- .... to flow dynamics and problems arising from the gas formation. Thus, all nuclear data information ... izations, large data files information management, evaluations, that include nuclear model based ...

  18. Ontology-driven geographic information systems

    Science.gov (United States)

    Fonseca, Frederico Torres

    Information integration is the combination of different types of information in a framework so that it can be queried, retrieved, and manipulated. Integration of geographic data has gained in importance because of the new possibilities arising from the interconnected world and the increasing availability of geographic information. Many times the need for information is so pressing that it does not matter if some details are lost, as long as integration is achieved. To integrate information across computerized information systems it is necessary first to have explicit formalizations of the mental concepts that people have about the real world. Furthermore, these concepts need to be grouped by communities in order to capture the basic agreements that exist within different communities. The explicit formalization of the mental models within a community is an ontology. This thesis introduces a framework for the integration of geographic information. We use ontologies as the foundation of this framework. By integrating ontologies that are linked to sources of geographic information we allow for the integration of geographic information based primarily on its meaning. Since the integration may occurs across different levels, we also create the basic mechanisms for enabling integration across different levels of detail. The use of an ontology, translated into an active, information-system component, leads Ontology-Driven Geographic Information Systems. The results of this thesis show that a model that incorporates hierarchies and roles has the potential to integrate more information than models that do not incorporate these concepts. We developed a methodology to evaluate the influence of the use of roles and of hierarchical structures for representing ontologies on the potential for information integration. The use of a hierarchical structure increases the potential for information integration. The use of roles also improves the potential for information integration

  19. Accelerator-driven transmutation of high-level waste from the defense and commercial sectors

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, C.; Arthur, E.; Beard, C. [and others

    1996-09-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The major goal has been to develop accelerator transmutation of waste (ATW) system designs that will thoroughly and rapidly transmute nuclear waste, including plutonium from dismantled weapons and spent reactor fuel, while generating useful electrical power and without producing a long-lived radioactive waste stream. We have identified and quantified the unique qualities of subcritical nuclear systems and their capabilities in bringing about the complete destruction of plutonium. Although the 1191 subcritical systems involved in our most effective designs radically depart from traditional nuclear reactor concepts, they are based on extrapolations of existing technologies. Overall, care was taken to retain the highly desired features that nuclear technology has developed over the years within a conservative design envelope. We believe that the ATW systems designed in this project will enable almost complete destruction of nuclear waste (conversion to stable species) at a faster rate and without many of the safety concerns associated with the possible reactor approaches.

  20. Mid-infrared Laser System Development for Dielectric Laser Accelerators

    Science.gov (United States)

    Jovanovic, Igor; Xu, Guibao; Wandel, Scott

    Laser-driven particle accelerators based on dielectric laser acceleration are under development and exhibit unique and challenging pump requirements. Operation in the mid-infrared (5 μm) range with short pulses (500 μJ) and good beam quality is required. We present our progress on the design and development of a novel two- stage source of mid-infrared pulses for this application, which is based on optical parametric amplification. Beta barium borate and zinc germanium phosphide crystals are used, and are pumped by a Ti:sapphire ultrashort laser and seeded by self-phase modulation and parametric generation-based sources.

  1. Electrophysical Systems Based On Charged Particle Accelerators

    CERN Document Server

    Vorogushin, M F

    2004-01-01

    The advancement of the charged particle accelerator engineering affects appreciably the modern tendencies of the scientific and technological progress in the world. In a number of advanced countries, this trend is one of the most dynamically progressing in the field of applied science and high-technology production. Such internationally known firms as VARIAN, SIEMENS, PHILIPS, ELECTA, IBA, HITACHI, etc., with an annual budget of milliards of dollars and growth rate of tens of percent may serve as an example. Although nowadays the projects of new large-scale accelerators for physical research are not implemented so quickly and frequently as desired, accelerating facilities are finding ever-widening application in various fields of human activities. The contribution made by Russian scientists into high-energy beams physics is generally known. High scientific and technical potential in this field, qualified personnel with a high creative potential, modern production and test facilities and state-of-the-art techn...

  2. Hacking control systems, switching… accelerators off?

    CERN Multimedia

    Computer Security Team

    2013-01-01

    In response to our article in the last Bulletin, we received the following comment: “Wasn’t Stuxnet designed to stop the Iranian nuclear programme? Why then all this noise with regard to CERN accelerators? Don’t you realize that ‘computer security’ is not the raison d'être of CERN?”. Thank you for this golden opportunity to delve into this issue.   Given the sophistication of Stuxnet, it might have been hard to detect such a targeted attack against CERN, if at all. But this is not the point. There are much simpler risks for our accelerator complex and infrastructure. And, while “‘computer security’ is [indeed] not the raison d' être”, it is our collective responsibility to keep this risk at bay.   Examples? Just think of a simple computer virus infecting Windows-based control PCs connected to the accelerator network (the Technical Network, &ld...

  3. [The security system of SIEMENS digital linear accelerator].

    Science.gov (United States)

    Wang, Jianping

    2013-03-01

    The security system plays an important role to protect the safety of patients and equipment in radiotherapy. The principle and structure of three kinds of security system of the Siemens digital linear accelerator were analyzed with some examples.

  4. Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator.

    Science.gov (United States)

    Gessner, Spencer; Adli, Erik; Allen, James M; An, Weiming; Clarke, Christine I; Clayton, Chris E; Corde, Sebastien; Delahaye, J P; Frederico, Joel; Green, Selina Z; Hast, Carsten; Hogan, Mark J; Joshi, Chan; Lindstrøm, Carl A; Lipkowitz, Nate; Litos, Michael; Lu, Wei; Marsh, Kenneth A; Mori, Warren B; O'Shea, Brendan; Vafaei-Najafabadi, Navid; Walz, Dieter; Yakimenko, Vitaly; Yocky, Gerald

    2016-06-02

    Plasma wakefield accelerators have been used to accelerate electron and positron particle beams with gradients that are orders of magnitude larger than those achieved in conventional accelerators. In addition to being accelerated by the plasma wakefield, the beam particles also experience strong transverse forces that may disrupt the beam quality. Hollow plasma channels have been proposed as a technique for generating accelerating fields without transverse forces. Here we demonstrate a method for creating an extended hollow plasma channel and measure the wakefields created by an ultrarelativistic positron beam as it propagates through the channel. The plasma channel is created by directing a high-intensity laser pulse with a spatially modulated profile into lithium vapour, which results in an annular region of ionization. A peak decelerating field of 230 MeV m(-1) is inferred from changes in the beam energy spectrum, in good agreement with theory and particle-in-cell simulations.

  5. Turbulent Rayleigh-Taylor flow driven by time-varying accelerations

    Science.gov (United States)

    Ramaprabhu, Praveen; Lawrie, Andrew; Muthuraman, Karthik; UNC-LMFA Collaboration

    2011-11-01

    We report on numerical simulations of turbulent Rayleigh-Taylor flow subject to variable acceleration histories. The acceleration profiles were inspired by experiments and theoretical studies, and include an impulsive acceleration, accel-decel profiles, as well as a constant drive as the baseline case. The simulations were performed using the MOBILE software, a variable-density, incompressible fluid flow code. The advection algorithm employs a 3rd-order, monotonicity-preserving upwind scheme, allowing the definition of sharp interfaces in the flow, while pressure convergence is accelerated by the use of a multi-grid scheme. The simulations are initialized with two classes of perturbations: narrow-band, short-wavelength modes and broadband with long-wavelength modes. The effect of initial amplitudes on the perturbations is investigated under the variable drive conditions. The acceleration profiles are capable of producing stages of ``demixing,'' useful in validating turbulence models of RTI.

  6. Accelerating Inexact Newton Schemes for Large Systems of Nonlinear Equations

    NARCIS (Netherlands)

    Fokkema, D.R.; Sleijpen, G.L.G.; Vorst, H.A. van der

    Classical iteration methods for linear systems, such as Jacobi iteration, can be accelerated considerably by Krylov subspace methods like GMRES. In this paper, we describe how inexact Newton methods for nonlinear problems can be accelerated in a similar way and how this leads to a general

  7. Differentiating between marketing-driven and technology-driven vendors of medical information systems.

    Science.gov (United States)

    Friedman, B A; Mitchell, W; Singh, K

    1994-08-01

    Buyers of medical information systems such as laboratory information systems need to recognize that the vendors of such systems may pursue corporate strategies emphasizing expenditures on marketing and client services, expenditures on technology and research and development (R&D), or a more balanced approach. The strategic goals and objectives of a vendor of an information system should align closely with those of a potential hospital client. A restless hospital client seeking cutting-edge technology will probably be dissatisfied with a system vendor who emphasizes slow ongoing incremental system development. Objective criteria for distinguishing between a marketing-driven vendor and a technology-driven vendor of medical information systems, and their variants, are presented based on the ratio of marketing expenditures to sales revenue compared with the ratio of research and development expenditures to sales revenue of the company. More subjective narrative criteria are also offered for making such distinctions.

  8. The Strongest Acceleration of >40 keV Electrons by ICME-driven Shocks at 1 au

    Science.gov (United States)

    Yang, Liu; Wang, Linghua; Li, Gang; Wimmer-Schweingruber, Robert F.; He, Jiansen; Tu, Chuanyi; Tian, Hui; Bale, Stuart D.

    2018-01-01

    We present two case studies of the in-situ electron acceleration during the 2000 February 11 shock and the 2004 July 22 shock, with the strongest electron flux enhancement at 40 keV across the shock, among all the quasi-perpendicular and quasi-parallel ICME-driven shocks observed by the WIND 3DP instrument from 1995 through 2014 at 1 au. We find that for this quasi-perpendicular (quasi-parallel) shock on 2000 February 11 (2004 July 22), the shocked electron differential fluxes at ∼0.4–50 keV in the downstream generally fit well to a double-power-law spectrum, J ∼ E ‑β , with an index of β ∼ 3.15 (4.0) at energies below a break at ∼3 keV (∼1 keV) and β ∼ 2.65 (2.6) at energies above. For both shock events, the downstream electron spectral indices appear to be similar for all pitch angles, which are significantly larger than the index prediction by diffusive shock acceleration. In addition, the downstream electron pitch-angle distributions show the anisotropic beams in the anti-sunward-traveling direction, while the ratio of the downstream over ambient fluxes appears to peak near 90° pitch angles, at all energies of ∼0.4–50 keV. These results suggest that in both shocks, shock drift acceleration likely plays an important role in accelerating electrons in situ at 1 au. Such ICME-driven shocks could contribute to the formation of solar wind halo electrons at energies ≲2 keV, as well as the production of solar wind superhalo electrons at energies ≳2 keV in interplanetary space.

  9. Theoretic programs related to spallation neutron source for ADS. Pt.2: Thick target simulations The ADS is stated for Accelector Driven System

    CERN Document Server

    Fan Sheng; Shen Qing Biao; Zhao Zhi Xiang

    2002-01-01

    The spallation neutron target for intermediate energy proton incident is an important link for accelerator and subcritical reactor of accelerator driven system (ADS). The theoretic programs and Monte-Carlo codes are a useful approach for solving the physics of spallation neutron source. The authors discuss those codes at present work and introduce the application and development of SHIELD code

  10. Multi-GPU Acceleration of Branchless Distance Driven Projection and Backprojection for Clinical Helical CT.

    Science.gov (United States)

    Mitra, Ayan; Politte, David G; Whiting, Bruce R; Williamson, Jeffrey F; O'Sullivan, Joseph A

    2017-01-01

    Model-based image reconstruction (MBIR) techniques have the potential to generate high quality images from noisy measurements and a small number of projections which can reduce the x-ray dose in patients. These MBIR techniques rely on projection and backprojection to refine an image estimate. One of the widely used projectors for these modern MBIR based technique is called branchless distance driven (DD) projection and backprojection. While this method produces superior quality images, the computational cost of iterative updates keeps it from being ubiquitous in clinical applications. In this paper, we provide several new parallelization ideas for concurrent execution of the DD projectors in multi-GPU systems using CUDA programming tools. We have introduced some novel schemes for dividing the projection data and image voxels over multiple GPUs to avoid runtime overhead and inter-device synchronization issues. We have also reduced the complexity of overlap calculation of the algorithm by eliminating the common projection plane and directly projecting the detector boundaries onto image voxel boundaries. To reduce the time required for calculating the overlap between the detector edges and image voxel boundaries, we have proposed a pre-accumulation technique to accumulate image intensities in perpendicular 2D image slabs (from a 3D image) before projection and after backprojection to ensure our DD kernels run faster in parallel GPU threads. For the implementation of our iterative MBIR technique we use a parallel multi-GPU version of the alternating minimization (AM) algorithm with penalized likelihood update. The time performance using our proposed reconstruction method with Siemens Sensation 16 patient scan data shows an average of 24 times speedup using a single TITAN X GPU and 74 times speedup using 3 TITAN X GPUs in parallel for combined projection and backprojection.

  11. A GPU Accelerated Spring Mass System for Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... to accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  12. Proposed Few-optical Cycle Laser-driven ParticleAccelerator Structure

    Energy Technology Data Exchange (ETDEWEB)

    Plettner, T.; Lu, P.; Byer, R.L.; /Stanford U., Ginzton Lab.

    2006-10-06

    We describe a transparent dielectric grating accelerator structure that is designed for ultra-short laser pulse operation. The structure is based on the principle of periodic field reversal to achieve phase synchronicity for relativistic particles, however to preserve ultra-short pulse operation it does not resonate the laser field in the vacuum channel. The geometry of the structure appears well suited for application with high average power lasers and high thermal loading. Finally, it shows potential for an unloaded gradient of 10 GeV/m with 10 fsec laser pulses and the possibility to accelerate 10{sup 6} electrons per bunch at an efficiency of 8%. The fabrication procedure and a proposed near term experiment with this accelerator structure are presented.

  13. A Magnetostrictive Tuning System for Particle Accelerators

    CERN Document Server

    Tai, Chiu-Ying; Daly, Edward; Davis, Kirk; Espinola, William; Han, Zhixiu; Joshi, Chandrashekhar; Mavanur, Anil; Racz, Livia; Shepard, Kenneth

    2005-01-01

    Energen, Inc. has designed, built, and demonstrated several fast and slow tuners based on its magnetostrictive actuators and stepper motor. These tuners are designed for Superconducting Radio Frequency (SRF) cavities, which are important structures in particle accelerators that support a wide spectrum of disciplines, including nuclear and high-energy physics and free electron lasers (FEL). In the past two years, Energen's work has focused on magnetostrictive fast tuners for microphonics and Lorentz detuning compensation on elliptical-cell and spoke-loaded cavities, including the capability for real-time closed-loop control. These tuners were custom designed to meet specific requirements, which included a few to 100 micron stroke range, hundreds to kilohertz operation frequency, and cryogenic temperature operation in vacuum or liquid helium. These tuners have been tested in house and at different laboratories, such as DESY, Argonne National Lab, and Jefferson Lab. Some recent results are presented in this pape...

  14. A Magnetorestrictive Tuning System for Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Chiu-Ying Tai; Jordan Cormier; William Espinola; Zhixiu Han; Chad Joshi; Anil Mavanur; Livia Racz; Kenneth Shepard; Edward Daly; Kirk Davis

    2005-05-16

    Energen, Inc. has designed, built, and demonstrated several fast and slow tuners based on its magnetostrictive actuators and stepper motor. These tuners are designed for Superconducting Radio Frequency (SRF) cavities, which are important structures in particle accelerators that support a wide spectrum of disciplines, including nuclear and high-energy physics and free electron lasers (FEL). In the past two years, Energen's work has focused on magnetostrictive fast tuners for microphonics and Lorentz detuning compensation on elliptical-cell and spoke-loaded cavities. These tuners were custom designed to meet specific requirements, which included a few to 100 micron stroke range, hundreds to kilohertz operation frequency, and cryogenic temperature operation in vacuum or liquid helium. These tuners have been tested in house and at different laboratories, such as DESY, Argonne National Lab, and Jefferson Lab. Some recent results are presented in this paper.

  15. COMPACT PROTON INJECTOR AND FIRST ACCELERATOR SYSTEM TEST FOR COMPACT PROTON DIELECTRIC WALL CANCER THERAPY ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y; Guethlein, G; Caporaso, G; Sampayan, S; Blackfield, D; Cook, E; Falabella, S; Harris, J; Hawkins, S; Nelson, S; Poole, B; Richardson, R; Watson, J; Weir, J; Pearson, D

    2009-04-23

    A compact proton accelerator for cancer treatment is being developed by using the high-gradient dielectric insulator wall (DWA) technology [1-4]. We are testing all the essential DWA components, including a compact proton source, on the First Article System Test (FAST). The configuration and progress on the injector and FAST will be presented.

  16. Sapphire capillaries for laser-driven wakefield acceleration in plasma. Fs-laser micromachining and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Schwinkendorf, Jan-Patrick

    2012-08-15

    Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. However, several detrimental effects such as laser diffraction, electron-wake dephasing and laser depletion may terminate the acceleration process. Two of these phenomena can be mitigated or avoided by the application of capillary waveguides, e.g. fabricated out of sapphire for longevity. Capillaries may compensate for laser diffraction like a fiber and allow for the creation of tapered gas-density profiles working against the dephasing between the accelerating wave and the particles. Additionally, they offer the possibility of controlled particle injection. This thesis is reporting on the set up of a laser for fs-micromachining of capillaries of almost arbitrary shapes and a test stand for density-profile characterization. These devices will permit the creation of tailored gas-density profiles for controlled electron injection and acceleration inside plasma.

  17. MONITORING STUDENT PERFORMANCE. A DATA DRIVEN DECISION SUPPORT SYSTEM APPROACH

    Directory of Open Access Journals (Sweden)

    Vasile GORGAN

    2015-06-01

    Full Text Available Data Driven Decision Support Systems are mature technologies whose effectiveness in business and management seem to be well established and uncontroversial. Under the circumstances of increased competition between universities in their attempt to better position themselves on the market of educational services, a Data Driven Decision Support System could become a powerful instrument meant to enhance all the decisions that target various aspects of the educational process. This paper is a case study conducted in a Romanian university, presenting the development of such a system, emphasizing the analytical capabilities related to student results at exams, as this topic is of interest for the users of the system.

  18. Revisiting the lid-driven cavity flow problem: Review and new steady state benchmarking results using GPU accelerated code

    Directory of Open Access Journals (Sweden)

    Tamer A. AbdelMigid

    2017-03-01

    Full Text Available This paper presents a broad account of the lid-driven cavity flow problem which is an important benchmark problem for the validation of CFD codes. A comprehensive review of the literature on the problem is presented and discussed, and available benchmarking results are compared in tabulated format to provide a comprehensive source of validation data. In addition, the problem was solved using a Graphical Processing Unit (GPU accelerated in-house code developed by the authors (https://github.com/TamerAbdelmigid/DrivenCavity_FVM.git, which solves the steady Navier-Stokes equations, using the Finite Volume Method (FVM in primitive variable formulation. Case studies of steady incompressible flow in a 2D lid-driven square cavity are investigated for 100 < Re < 5000. Detailed second order spatially accurate results are verified and presented in a tabulated form for the sake of serving as benchmark dataset for future works on the same problem. In the present work, collocated grid arrangement along with a uniform structured Cartesian grid up to 1301 × 1301 was used.

  19. Self-generated surface magnetic fields inhibit laser-driven sheath acceleration of high-energy protons.

    Science.gov (United States)

    Nakatsutsumi, M; Sentoku, Y; Korzhimanov, A; Chen, S N; Buffechoux, S; Kon, A; Atherton, B; Audebert, P; Geissel, M; Hurd, L; Kimmel, M; Rambo, P; Schollmeier, M; Schwarz, J; Starodubtsev, M; Gremillet, L; Kodama, R; Fuchs, J

    2018-01-18

    High-intensity lasers interacting with solid foils produce copious numbers of relativistic electrons, which in turn create strong sheath electric fields around the target. The proton beams accelerated in such fields have remarkable properties, enabling ultrafast radiography of plasma phenomena or isochoric heating of dense materials. In view of longer-term multidisciplinary purposes (e.g., spallation neutron sources or cancer therapy), the current challenge is to achieve proton energies well in excess of 100 MeV, which is commonly thought to be possible by raising the on-target laser intensity. Here we present experimental and numerical results demonstrating that magnetostatic fields self-generated on the target surface may pose a fundamental limit to sheath-driven ion acceleration for high enough laser intensities. Those fields can be strong enough (~10 5  T at laser intensities ~10 21  W cm -2 ) to magnetize the sheath electrons and deflect protons off the accelerating region, hence degrading the maximum energy the latter can acquire.

  20. High-quality electron beams from beam-driven plasma accelerators by wakefield-induced ionization injection.

    Science.gov (United States)

    Martinez de la Ossa, A; Grebenyuk, J; Mehrling, T; Schaper, L; Osterhoff, J

    2013-12-13

    We propose a new and simple strategy for controlled ionization-induced trapping of electrons in a beam-driven plasma accelerator. The presented method directly exploits electric wakefields to ionize electrons from a dopant gas and capture them into a well-defined volume of the accelerating and focusing wake phase, leading to high-quality witness bunches. This injection principle is explained by example of three-dimensional particle-in-cell calculations using the code OSIRIS. In these simulations a high-current-density electron-beam driver excites plasma waves in the blowout regime inside a fully ionized hydrogen plasma of density 5×10(17)cm-3. Within an embedded 100  μm long plasma column contaminated with neutral helium gas, the wakefields trigger ionization, trapping of a defined fraction of the released electrons, and subsequent acceleration. The hereby generated electron beam features a 1.5 kA peak current, 1.5  μm transverse normalized emittance, an uncorrelated energy spread of 0.3% on a GeV-energy scale, and few femtosecond bunch length.

  1. Data-driven optimization of dynamic reconfigurable systems of systems.

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, Conrad S.; Eddy, John P.

    2010-11-01

    This report documents the results of a Strategic Partnership (aka University Collaboration) LDRD program between Sandia National Laboratories and the University of Illinois at Urbana-Champagne. The project is titled 'Data-Driven Optimization of Dynamic Reconfigurable Systems of Systems' and was conducted during FY 2009 and FY 2010. The purpose of this study was to determine and implement ways to incorporate real-time data mining and information discovery into existing Systems of Systems (SoS) modeling capabilities. Current SoS modeling is typically conducted in an iterative manner in which replications are carried out in order to quantify variation in the simulation results. The expense of many replications for large simulations, especially when considering the need for optimization, sensitivity analysis, and uncertainty quantification, can be prohibitive. In addition, extracting useful information from the resulting large datasets is a challenging task. This work demonstrates methods of identifying trends and other forms of information in datasets that can be used on a wide range of applications such as quantifying the strength of various inputs on outputs, identifying the sources of variation in the simulation, and potentially steering an optimization process for improved efficiency.

  2. Scheduling Driven Partitioning of Heterogeneous Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    1998-01-01

    In this paper we present an algorithm for system level hardware/software partitioning of heterogeneous embedded systems. The system is represented as an abstract graph which captures both data-flow and the flow of control. Given an architecture consisting of several processors, ASICs and shared b...

  3. The screen hole plasma sheath of an ion accelerator system

    Science.gov (United States)

    Aston, G.; Wilbur, P. J.

    1979-01-01

    Results of the first probing of the screen hole sheath of an ion accelerator system are presented. The screen hole sheath, represented as a set of equipotential contours, extends over a large distance within the discharge plasma. Under no conditions examined does the sheath enter the screen hole. Edge hole defocusing of multiaperture accelerator systems is due primarily to local plasma density variations rather than adjacent screen hole sheath interactions. The sheath boundary is independent of screen-to-accelerator grid spacing when the grid set is operated at the minimum ion beam divergence condition. Significant ion focusing effects occur in the sheath adjacent to the screen grid webbing leading to increased ion source beam current efficiency with decreasing screen-to-accelerator grid separation and/or screen grid thickness.

  4. A mobile console for local access to accelerator control systems.

    CERN Multimedia

    1981-01-01

    Microprocessors were installed as auxiliary crate controllers (ACCs) in the CAMAC interface of control systems for various accelerators. The same ACC was also at the hearth of a stand-alone system in the form of a mobile console. This was also used for local access to the control systems for tests and development work (Annual Report 1981, p. 80, Fig. 10).

  5. CHEBYSHEV ACCELERATION TECHNIQUE FOR SOLVING FUZZY LINEAR SYSTEM

    Directory of Open Access Journals (Sweden)

    S.H. Nasseri

    2009-10-01

    Full Text Available In this paper, Chebyshev acceleration technique is used to solve the fuzzy linear system (FLS. This method is discussed in details and followed by summary of some other acceleration techniques. Moreover, we show that in some situations that the methods such as Jacobi, Gauss-Sidel, SOR and conjugate gradient is divergent, our proposed method is applicable and the acquired results are illustrated by some numerical examples.

  6. Accelerating the development of transparent graphene electrodes through basic science driven chemical functionalization.

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Calvin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beechem, III, Thomas Edwin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ohta, Taisuke [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brumbach, Michael T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wheeler, David Roger [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Veneman, Alexander [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gearba, I. Raluca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stevenson, Keith J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-09-01

    Chemical functionalization is required to adapt graphenes properties to many applications. However, most covalent functionalization schemes are spontaneous or defect driven and are not suitable for applications requiring directed assembly of molecules on graphene substrates. In this work, we demonstrated electrochemically driven covalent bonding of phenyl iodoniums onto epitaxial graphene. The amount of chemisorption was demonstrated by varying the duration of the electrochemical driving potential. Chemical, electronic, and defect states of phenyl-modified graphene were studied by photoemission spectroscopy, spatially resolved Raman spectroscopy, and water contact angle measurement. Covalent attachment rehybridized some of the delocalized graphene sp2 orbitals to localized sp3 states. Control over the relative spontaneity (reaction rate) of covalent graphene functionalization is an important first step to the practical realization of directed molecular assembly on graphene. More than 10 publications, conference presentations, and program highlights were produced (some invited), and follow-on funding was obtained to continue this work.

  7. The multi-computer control system for the CERN 400 GeV accelerator

    CERN Document Server

    Crowley-Milling, Michael C; Shering, G C

    1975-01-01

    Discusses three trends in the application of computer control to accelerators. These are the trends towards multi-computer control systems, the use of computer driven operator interaction devices, and the use of interpretive highlevel language software. The computer control system for the new CERN 400 GeV synchrotron carries these trends to their extremes. It consists of 24 essentially similar computers linked together using serial data links and a message transfer computer. The software is based on an interpreter for a high level interactive language NODAL. This is used as an operator command language and as a high level application programming language. (2 refs).

  8. Compton scattering x-ray sources driven by laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    F. V. Hartemann

    2007-01-01

    Full Text Available Recent laser wakefield acceleration experiments have demonstrated the generation of femtosecond, nano-Coulomb, low emittance, nearly monokinetic relativistic electron bunches of sufficient quality to produce bright, tunable, ultrafast x-rays via Compton scattering. Design parameters for a proof-of-concept experiment are presented using a three-dimensional Compton scattering code and a laser-plasma interaction particle-in-cell code modeling the wakefield acceleration process; x-ray fluxes exceeding 10^{21}   s^{-1} are predicted, with a peak brightness >10^{19}   photons/(mm^{2} mrad^{2} s   0.1%   bandwidth.

  9. Matching sub-fs electron bunches for laser-driven plasma acceleration at SINBAD

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J., E-mail: jun.zhu@desy.de [Deutsches Elektronen-Synchrotron, DESY, Hamburg (Germany); Universität Hamburg, Hamburg (Germany); Assmann, R.W.; Dorda, U.; Marchetti, B. [Deutsches Elektronen-Synchrotron, DESY, Hamburg (Germany)

    2016-09-01

    We present theoretical and numerical studies of matching sub-femtosecond space-charge-dominated electron bunch into the Laser-plasma Wake Field Accelerator (LWFA) foreseen at the SINBAD facility. The longitudinal space-charge (SC) effect induced growths of the energy spread and longitudinal phase-space chirp are major issues in the matching section, which will result in bunch elongation, emittance growth and spot size dilution. In addition, the transverse SC effect would lead to a mismatch of the beam optics if it were not compensated for. Start-to-end simulations and preliminary optimizations were carried out in order to understand the achievable beam parameters at the entrance of the plasma accelerator.

  10. Development of a wireless displacement measurement system using acceleration responses.

    Science.gov (United States)

    Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F

    2013-07-01

    Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system.

  11. Dynamic Data Driven Operator Error Early Warning System

    Science.gov (United States)

    2015-08-13

    AFRL-AFOSR-VA-TR-2015-0291 Dynamic Data Driven Operator Error Early Warning System Alok Chaturvedi PURDUE UNIVERSITY Final Report 08/13/2015...14-04-2015 4. TITLE AND SUBTITLE Dynamic Data Driven Operator Error Early Warning System 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0058 5c...cognitive activities), 3 types of sensors were used in the proposed experiment. A B- Alert X10 EEG headset system (Advanced Brain Monitoring, Inc., USA

  12. Design of a high average-power FEL driven by an existing 20 MV electrostatic-accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kimel, I.; Elias, L.R. [Univ. of Central Florida, Orlando, FL (United States)

    1995-12-31

    There are some important applications where high average-power radiation is required. Two examples are industrial machining and space power-beaming. Unfortunately, up to date no FEL has been able to show more than 10 Watts of average power. To remedy this situation we started a program geared towards the development of high average-power FELs. As a first step we are building in our CREOL laboratory, a compact FEL which will generate close to 1 kW in CW operation. As the next step we are also engaged in the design of a much higher average-power system based on a 20 MV electrostatic accelerator. This FEL will be capable of operating CW with a power output of 60 kW. The idea is to perform a high power demonstration using the existing 20 MV electrostatic accelerator at the Tandar facility in Buenos Aires. This machine has been dedicated to accelerate heavy ions for experiments and applications in nuclear and atomic physics. The necessary adaptations required to utilize the machine to accelerate electrons will be described. An important aspect of the design of the 20 MV system, is the electron beam optics through almost 30 meters of accelerating and decelerating tubes as well as the undulator. Of equal importance is a careful design of the long resonator with mirrors able to withstand high power loading with proper heat dissipation features.

  13. MODEL DRIVEN DEVELOPMENT OF ONLINE BANKING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Bresfelean Vasile Paul

    2011-07-01

    Full Text Available In case of online applications the cycle of software development varies from the routine. The online environment, the variety of users, the treatability of the mass of information created by them, the reusability and the accessibility from different devices are all factors of these systems complexity. The use of model drive approach brings several advantages that ease up the development process. Working prototypes that simplify client relationship and serve as the base of model tests can be easily made from models describing the system. These systems make possible for the banks clients to make their desired actions from anywhere. The user has the possibility of accessing information or making transactions.

  14. Acceleration display system for aircraft zero-gravity research

    Science.gov (United States)

    Millis, Marc G.

    1987-01-01

    The features, design, calibration, and testing of Lewis Research Center's acceleration display system for aircraft zero-gravity research are described. Specific circuit schematics and system specifications are included as well as representative data traces from flown trajectories. Other observations learned from developing and using this system are mentioned where appropriate. The system, now a permanent part of the Lewis Learjet zero-gravity program, provides legible, concise, and necessary guidance information enabling pilots to routinely fly accurate zero-gravity trajectories. Regular use of this system resulted in improvements of the Learjet zero-gravity flight techniques, including a technique to minimize later accelerations. Lewis Gates Learjet trajectory data show that accelerations can be reliably sustained within 0.01 g for 5 consecutive seconds, within 0.02 g for 7 consecutive seconds, and within 0.04 g for up to 20 second. Lewis followed the past practices of acceleration measurement, yet focussed on the acceleration displays. Refinements based on flight experience included evolving the ranges, resolutions, and frequency responses to fit the pilot and the Learjet responses.

  15. 46 CFR 169.623 - Power-driven steering systems.

    Science.gov (United States)

    2010-10-01

    ... system must automatically resume operation after an electric power outage. (b) Control of power-driven steering systems from the main steering control location must include, as applicable— (1) Control of any necessary ancillary device (motor, pump, valve, etc.); (2) A pilot light to indicate operation of each power...

  16. Feasibility of Optical Transition Radiation Imaging for Laser-driven Plasma Accelerator Electron-Beam Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Rule, D. W. [Unlisted, US, MD; Downer, M. C. [Texas U.

    2017-10-09

    We report the initial considerations of using linearly polarized optical transition radiation (OTR) to characterize the electron beams of laser plasma accelerators (LPAs) such as at the Univ. of Texas at Austin. The two LPAs operate at 100 MeV and 2-GeV, and they currently have estimated normalized emittances at ~ 1-mm mrad regime with beam divergences less than 1/γ and beam sizes to be determined at the micron level. Analytical modeling results indicate the feasibility of using these OTR techniques for the LPA applications.

  17. Electron beam characteristics of a laser-driven plasma wakefield accelerator

    CERN Document Server

    Assamagan, Ketevi A; Chen, S Y; Ent, R; Green, R N; Gueye, P; Keppel, C; Mourou, G; Umstadter, D; Wagner, R

    1999-01-01

    The properties of an electron beam trapped and accelerated in a laser wakefield have been investigated. Plastic scintillating fibers were employed together with position sensitive photomultiplier tubes (PMT) and a series of dipole electro-magnets to study the beam. The measured momentum spectrum peaks around 7 MeV/c with an exponential fall-off at high momenta up to (70.3+- 19.9) MeV/c. The number of electrons detected per bunch is determined to be (2.6+-0.3)x10 sup 1 sup 1.

  18. A “slingshot” laser-driven acceleration mechanism of plasma electrons

    Energy Technology Data Exchange (ETDEWEB)

    Fiore, Gaetano, E-mail: gaetano.fiore@na.infn.it [Dip. di Matematica e Applicazioni, Università “Federico II”, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); De Nicola, Sergio [SPIN-CNR, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy)

    2016-09-01

    We briefly report on the recently proposed Fiore et al. [1] and Fiore and De Nicola [2] electron acceleration mechanism named “slingshot effect”: under suitable conditions the impact of an ultra-short and ultra-intense laser pulse against the surface of a low-density plasma is expected to cause the expulsion of a bunch of superficial electrons with high energy in the direction opposite to that of the pulse propagation; this is due to the interplay of the huge ponderomotive force, huge longitudinal field arising from charge separation, and the finite size of the laser spot.

  19. Portable database driven control system for SPEAR

    Energy Technology Data Exchange (ETDEWEB)

    Howry, S.; Gromme, T.; King, A.; Sullenberger, M.

    1985-04-01

    The new computer control system software for SPEAR is presented as a transfer from the PEP system. Features of the target ring (SPEAR) such as symmetries, magnet groupings, etc., are all contained in a design file which is read by both people and computer. People use it as documentation; a program reads it to generate the database structure, which becomes the center of communication for all the software. Geometric information, such as element positions and lengths, and CAMAC I/O routing information is entered into the database as it is developed. Since application processes refer only to the database and since they do so only in generic terms, almost all of this software (representing more then fifteen man years) is transferred with few changes. Operator console menus (touchpanels) are also transferred with only superficial changes for the same reasons. The system is modular: the CAMAC I/O software is all in one process; the menu control software is a process; the ring optics model and the orbit model are separate processes, each of which runs concurrently with about 15 others in the multiprogramming environment of the VAX/VMS operating system. 10 refs., 1 fig.

  20. Database Driven Web Systems for Education.

    Science.gov (United States)

    Garrison, Steve; Fenton, Ray

    1999-01-01

    Provides technical information on publishing to the Web. Demonstrates some new applications in database publishing. Discusses the difference between static and database-drive Web pages. Reviews failures and successes of a Web database system. Addresses the question of how to build a database-drive Web site, discussing connectivity software, Web…

  1. Microbioreactor Systems for Accelerated Bioprocess Development.

    Science.gov (United States)

    Hemmerich, Johannes; Noack, Stephan; Wiechert, Wolfgang; Oldiges, Marco

    2017-12-28

    In recent years, microbioreactor (MBR) systems have evolved towards versatile bioprocess engineering tools. They provide a unique solution to combine higher experimental throughput with extensive bioprocess monitoring and control, which is indispensable to develop economically and ecologically competitive bioproduction processes. MBR systems are based either on down-scaled stirred tank reactors or on advanced shaken microtiter plate cultivation devices. Importantly, MBR systems make use of optical measurements for non-invasive, online monitoring of important process variables like biomass concentration, dissolved oxygen, pH, and fluorescence. The application range of MBR systems can be further increased by integration into liquid handling robots, enabling automatization and, thus standardization, of various handling and operation procedures. Finally, the tight integration of quantitative strain phenotyping with bioprocess development under industrially relevant conditions greatly increases the probability of finding the right combination of producer strain and bioprocess control strategy. This review will discuss the current state of the art in the field of MBR systems and we can readily conclude that their importance for industrial biotechnology will further increase in the near future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Ion acceleration driven by a relativistic electron beam under a strong magnetic field

    Science.gov (United States)

    Taguchi, Toshihiro; Antonsen, Thomas; Mima, Kunioki

    2017-10-01

    We have been investigating about an electron beam propagation under a strong magnetic field and found a very interesting phenomena. It is a generation of a large amplitude whistler wave, which is amplified by a nonlinear coupling of obliquely propagating circularly polarized waves. Since the previous work did not include ion motions, such a giant whistler wave mainly affects on beam electrons and they stagnate due to a large ponderomotive force of the electromagnetic wave. In order to investigate the influence of the strong wave on background ions, we have developed a new PIC code which has an open (upstream and downstream) boundaries. By using the new code, we have been studying the kinetic behavior of ions in a circumstance generating a large whistler wave. As a result, it is found that the electrostatic field induced by the stagnated beam electrons not only creates a density dip in the background electrons but also accelerates background ions. We will discuss the relation between the ion acceleration and a formation of a collisionless shock wave. This work was supported by a Grant-in-Aid for Scientific Research (B), 15H03758.

  3. Assessment of candidates for target window material in accelerator-driven molybdenum-99 production

    Energy Technology Data Exchange (ETDEWEB)

    Strons, Philip [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, James [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-01

    NorthStar Medical Technologies is pursuing production of an important medical isotope, Mo-99, through a photo-nuclear reaction of a Mo-100 target using a high-power electron accelerator. The current target utilizes an Inconel 718 window. The purpose of this study was to evaluate other candidate materials for the target window, which separates the high-pressure helium gas inside the target from the vacuum inside the accelerator beamline and is subjected to significant stress. Our initial analysis assessed the properties (density, thermal conductivity, maximum stress, minimum window thickness, maximum temperature, and figure of merit) for a range of materials, from which the three most promising were chosen: Inconel 718, 250 maraging steel, and standard-grade beryllium. These materials were subjected to further analysis to determine the effects of thermal and mechanical strain versus beam power at varying thicknesses. Both beryllium and the maraging steel were calculated to withstand more than twice as high beam power than Inconel 718.

  4. High repetition rate laser-driven MeV ion acceleration at variable background pressures

    Science.gov (United States)

    Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

    2017-10-01

    Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  5. The Database Driven ATLAS Trigger Configuration System

    CERN Document Server

    Martyniuk, Alex; The ATLAS collaboration

    2015-01-01

    This contribution describes the trigger selection configuration system of the ATLAS low- and high-level trigger (HLT) and the upgrades it received in preparation for LHC Run 2. The ATLAS trigger configuration system is responsible for applying the physics selection parameters for the online data taking at both trigger levels and the proper connection of the trigger lines across those levels. Here the low-level trigger consists of the already existing central trigger (CT) and the new Level-1 Topological trigger (L1Topo), which has been added for Run 2. In detail the tasks of the configuration system during the online data taking are Application of the selection criteria, e.g. energy cuts, minimum multiplicities, trigger object correlation, at the three trigger components L1Topo, CT, and HLT On-the-fly, e.g. rate-dependent, generation and application of prescale factors to the CT and HLT to adjust the trigger rates to the data taking conditions, such as falling luminosity or rate spikes in the detector readout ...

  6. Space Launch System Accelerated Booster Development Cycle

    Science.gov (United States)

    Arockiam, Nicole; Whittecar, William; Edwards, Stephen

    2012-01-01

    With the retirement of the Space Shuttle, NASA is seeking to reinvigorate the national space program and recapture the public s interest in human space exploration by developing missions to the Moon, near-earth asteroids, Lagrange points, Mars, and beyond. The would-be successor to the Space Shuttle, NASA s Constellation Program, planned to take humans back to the Moon by 2020, but due to budgetary constraints was cancelled in 2010 in search of a more "affordable, sustainable, and realistic" concept2. Following a number of studies, the much anticipated Space Launch System (SLS) was unveiled in September of 2011. The SLS core architecture consists of a cryogenic first stage with five Space Shuttle Main Engines (SSMEs), and a cryogenic second stage using a new J-2X engine3. The baseline configuration employs two 5-segment solid rocket boosters to achieve a 70 metric ton payload capability, but a new, more capable booster system will be required to attain the goal of 130 metric tons to orbit. To this end, NASA s Marshall Space Flight Center recently released a NASA Research Announcement (NRA) entitled "Space Launch System (SLS) Advanced Booster Engineering Demonstration and/or Risk Reduction." The increased emphasis on affordability is evident in the language used in the NRA, which is focused on risk reduction "leading to an affordable Advanced Booster that meets the evolved capabilities of SLS" and "enabling competition" to "enhance SLS affordability. The purpose of the work presented in this paper is to perform an independent assessment of the elements that make up an affordable and realistic path forward for the SLS booster system, utilizing advanced design methods and technology evaluation techniques. The goal is to identify elements that will enable a more sustainable development program by exploring the trade space of heavy lift booster systems and focusing on affordability, operability, and reliability at the system and subsystem levels5. For this study

  7. Dynamic Systems Driven by Non-Poissonian Impulses

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Iwankiewicz, R.

    Dynamic systems under random trains of impulses driven by renewal point processes are studied. Then the system state variables no longer form a Markov vector as it is in the case of Poisson impulses. A general format is given for the replacing an ordinary renewal process by an equivalent Poisson...... process at the expense of the introduction of auxiliary state variables. A technique is devised for truncating the hierarchy of stochastic equations governing the auxiliary state variables. For the generalized Erlang process, suitable for approximating a wide class of renewal processes, the technique...... is developed for modelling it, via suitable choice of parameters, with the help of a Poisson driven process. The theory is illustrated for a Duffing oscillator under the impulses driven by the generalized Erlang process of the order k=2approximating an original renewal process with a lognormally distributed...

  8. AQUA: an ontology driven question answering system

    OpenAIRE

    Vargas-Vera, Maria; Motta, Enrico; Domingue, John

    2003-01-01

    This paper describes AQUA our question answering over the Web. AQUA was designed to work over heterogeneous sources. This means that AQUA is equipped to work as closed domain and in addition to open-domain question answering. As a first instance, AQUA tries to answer a question using a Knowledge base. If a query cannot be satisfied over a knowledge base/database. Then, AQUA tries to find an answer on web pages (i.e. it uses as corpus the internet as resource). Our system uses NLP (Natural Lan...

  9. Overview of the IBA accelerator-based BNCT system

    Energy Technology Data Exchange (ETDEWEB)

    Forton, E. [Ion Beam Applications s.a., Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium)], E-mail: eric.forton@iba-group.com; Stichelbaut, F.; Cambriani, A.; Kleeven, W.; Ahlback, J.; Jongen, Y. [Ion Beam Applications s.a., Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium)

    2009-07-15

    During the last few years, IBA started the development of an accelerator-based BNCT system. The accelerator is a Dynamitron built by RDI in USA and will produce a 20 mA proton beam at 2.8 MeV. Neutrons will be produced by the {sup 7}Li(p,n){sup 7}Be nuclear reaction using a thin lithium target. The neutron energy spectrum will be tailored using a beam shaping assembly. This overview presents the current status of the system: after a description of every component, some design issues, solutions and experimental tests will be discussed.

  10. Overview of the IBA accelerator-based BNCT system.

    Science.gov (United States)

    Forton, E; Stichelbaut, F; Cambriani, A; Kleeven, W; Ahlback, J; Jongen, Y

    2009-07-01

    During the last few years, IBA started the development of an accelerator-based BNCT system. The accelerator is a Dynamitron built by RDI in USA and will produce a 20 mA proton beam at 2.8 MeV. Neutrons will be produced by the (7)Li(p,n)(7)Be nuclear reaction using a thin lithium target. The neutron energy spectrum will be tailored using a beam shaping assembly. This overview presents the current status of the system: after a description of every component, some design issues, solutions and experimental tests will be discussed.

  11. Natural noise and external wakefield seeding in a proton-driven plasma accelerator

    Directory of Open Access Journals (Sweden)

    K. V. Lotov

    2013-04-01

    Full Text Available An accurate description of noise levels is of crucial importance for the correct simulation of instability-driven processes, such as the density modulation of a long proton bunch traversing a plasma. To insure that the correct instability develops, a seed field must be larger than the cumulative shot noise. We develop an analytical theory of the noise field and compare it with multidimensional simulations. We find that the natural noise wakefield generated in a plasma by the CERN Super Proton Synchrotron bunches is very low, at the level of 10  kV/m. This fortunate fact eases the requirements on the seed. Our three-dimensional simulations show that even a few tens MeV electron bunch precursor of a very moderate intensity is sufficient to seed the proton bunch self-modulation in plasma.

  12. Lead cooled heterogeneous accelerator driven molten-fluoride blanket for incineration of long-lived radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lopatkin, A.V.; Matyushechkin, V.M.; Tretyakov, I.T. [Research and Development Inst. of Power Engineering, Moscow (Russian Federation); Blagovolin, P.P.; Kazaritsky, V.D. [State Scientific Centre, Moscow (Russian Federation). Inst. of Theoretical and Experimental Physics; Kostenkov, V.I.; Chuvilin, D.Yu. [I.V. Kurchatov Inst., Moscow (Russian Federation)

    1997-09-01

    This paper presents a tentative design description and evaluation of the basic parameters of a lead cooled heterogeneous accelerator driven molten fluoride blanket. The proton beam of a 1 GeV accelerator strikes the blanket from below and generates spallation neutrons in the flow of lead, which serves as a target. These neutrons leave the target zone and get into a heterogeneous blanket with separated volumes of molten salts and lead. Fissile materials are dissolved in the salt. On getting into the molten salt volume the neutrons cause fission (transmutation) of the actinides, the produced heat being removed by circulation of molten lead. Two versions of the blanket design are examined. The first version: molten salt circulates in the fuel channels, while lead cools the channels flowing through the interchannel space (the salt channel design). The second version: it is lead that circulates in the channels, while molten salt takes up the interchannel space (the lead channel design). A preliminary blanket design study showed that both blanket designs possess a potential for improving performance. At present time the blanket design, mentioned above as the salt channel design, seems to be more promising. 1 ref., 2 figs., 2 tabs.

  13. Electron yield enhancement in a laser wakefield accelerator driven by asymmetric laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Leemans, W.P.; Catravas, P.; Esarey, E.; Geddes, C.G.R.; Toth, C.; Trines, R.; Schroeder, C.B.; Shadwick, B.A.; van Tilborg, J.; Faure, J.

    2002-08-01

    The effect of asymmetric laser pulses on electron yield from a laser wakefield accelerator has been experimentally studied using > 10{sup 19} cm{sup -3} plasmas and a 10 TW, > 45 fs, Ti:Al{sub 2}O{sub 3} laser. Laser pulse shape was controlled through non-linear chirp with a grating pair compressor. Pulses (76 fs FWHM) with a steep rise and positive chirp were found to significantly enhance the electron yield compared to pulses with a gentle rise and negative chirp. Theory and simulation show that fast rising pulses can generate larger amplitude wakes that seed the growth of the self-modulation instability and that frequency chirp is of minimal importance for the experimental parameters.

  14. Electron bow-wave injection of electrons in laser-driven bubble acceleration.

    Science.gov (United States)

    Ma, Y Y; Kawata, S; Yu, T P; Gu, Y Q; Sheng, Z M; Yu, M Y; Zhuo, H B; Liu, H J; Yin, Y; Takahashi, K; Xie, X Y; Liu, J X; Tian, C L; Shao, F Q

    2012-04-01

    An electron injection regime in laser wake-field acceleration, namely electron bow-wave injection, is investigated by two- and three-dimensional particle-in-cell simulation as well as analytical model. In this regime electrons in the intense electron bow wave behind the first bubble catch up with the bubble tail and are trapped by the bubble finally, resulting in considerable enhancement of the total trapped electron number. For example, with the increase of the laser intensity from 2 × 10(19) to 1 × 10(20) W/cm(2), the electron trapping changes from normal self-injection to bow-wave injection and the trapped electron number is enhanced by two orders of magnitude. An analytical model is proposed to explain the numerical observation.

  15. Laser-Driven Very High Energy Electron/Photon Beam Radiation Therapy in Conjunction with a Robotic System

    Directory of Open Access Journals (Sweden)

    Kazuhisa Nakajima

    2014-12-01

    Full Text Available We present a new external-beam radiation therapy system using very-high-energy (VHE electron/photon beams generated by a centimeter-scale laser plasma accelerator built in a robotic system. Most types of external-beam radiation therapy are delivered using a machine called a medical linear accelerator driven by radio frequency (RF power amplifiers, producing electron beams with an energy range of 6–20 MeV, in conjunction with modern radiation therapy technologies for effective shaping of three-dimensional dose distributions and spatially accurate dose delivery with imaging verification. However, the limited penetration depth and low quality of the transverse penumbra at such electron beams delivered from the present RF linear accelerators prevent the implementation of advanced modalities in current cancer treatments. These drawbacks can be overcome if the electron energy is increased to above 50 MeV. To overcome the disadvantages of the present RF-based medical accelerators, harnessing recent advancement of laser-driven plasma accelerators capable of producing 1-GeV electron beams in a 1-cm gas cell, we propose a new embodiment of the external-beam radiation therapy robotic system delivering very high-energy electron/photon beams with an energy of 50–250 MeV; it is more compact, less expensive, and has a simpler operation and higher performance in comparison with the current radiation therapy system.

  16. Laser-driven particle acceleration for radiobiology and radiotherapy: where we are and where we are going

    Science.gov (United States)

    Giulietti, Antonio

    2017-05-01

    Radiation therapy of tumors progresses continuously and so do devices, sharing a global market of about $ 4 billions, growing at an annual rate exceeding 5%. Most of the progress involves tumor targeting, multi-beam irradiation, reduction of damage on healthy tissues and critical organs, dose fractioning. This fast-evolving scenario is the moving benchmark for the progress of the laser-based accelerators towards clinical uses. As for electrons, both energy and dose requested by radiotherapy are available with plasma accelerators driven by lasers in the power range of tens of TW but several issues have still to be faced before getting a prototype device for clinical tests. They include capability of varying electron energy, stability of the process, reliability for medical users. On the other side hadron therapy, presently applied to a small fraction of cases but within an exponential growth, is a primary option for the future. With such a strong motivation, research on laser-based proton/ion acceleration has been supported in the last decade in order to get performances suitable to clinical standards. None of these performances has been achieved so far with laser techniques. In the meantime a rich crop of data have been obtained in radiobiological experiments performed with beams of particles produced with laser techniques. It is quite significant however that most of the experiments have been performed moving bio samples to laser labs, rather moving laser equipment to bio labs or clinical contexts. This give us the measure that laser community cannot so far provide practical devices usable by non-laser people.

  17. PEPSI-Dock: a detailed data-driven protein-protein interaction potential accelerated by polar Fourier correlation.

    Science.gov (United States)

    Neveu, Emilie; Ritchie, David W; Popov, Petr; Grudinin, Sergei

    2016-09-01

    Docking prediction algorithms aim to find the native conformation of a complex of proteins from knowledge of their unbound structures. They rely on a combination of sampling and scoring methods, adapted to different scales. Polynomial Expansion of Protein Structures and Interactions for Docking (PEPSI-Dock) improves the accuracy of the first stage of the docking pipeline, which will sharpen up the final predictions. Indeed, PEPSI-Dock benefits from the precision of a very detailed data-driven model of the binding free energy used with a global and exhaustive rigid-body search space. As well as being accurate, our computations are among the fastest by virtue of the sparse representation of the pre-computed potentials and FFT-accelerated sampling techniques. Overall, this is the first demonstration of a FFT-accelerated docking method coupled with an arbitrary-shaped distance-dependent interaction potential. First, we present a novel learning process to compute data-driven distant-dependent pairwise potentials, adapted from our previous method used for rescoring of putative protein-protein binding poses. The potential coefficients are learned by combining machine-learning techniques with physically interpretable descriptors. Then, we describe the integration of the deduced potentials into a FFT-accelerated spherical sampling provided by the Hex library. Overall, on a training set of 163 heterodimers, PEPSI-Dock achieves a success rate of 91% mid-quality predictions in the top-10 solutions. On a subset of the protein docking benchmark v5, it achieves 44.4% mid-quality predictions in the top-10 solutions when starting from bound structures and 20.5% when starting from unbound structures. The method runs in 5-15 min on a modern laptop and can easily be extended to other types of interactions. https://team.inria.fr/nano-d/software/PEPSI-Dock sergei.grudinin@inria.fr. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e

  18. The maximum principle in optimal control of systems driven by ...

    African Journals Online (AJOL)

    We study the relaxed optimal stochastic control problem for systems governed by stochastic differential equations (SDEs), driven by an orthogonal continuous martingale measure, where the control is allowed to enter both the drift and diffusion coeffcient. The set of admissible controls is a set of measure-valued processes.

  19. LU factorization for accelerator-based systems

    KAUST Repository

    Agullo, Emmanuel

    2011-12-01

    Multicore architectures enhanced with multiple GPUs are likely to become mainstream High Performance Computing (HPC) platforms in a near future. In this paper, we present the design and implementation of an LU factorization using tile algorithm that can fully exploit the potential of such platforms in spite of their complexity. We use a methodology derived from previous work on Cholesky and QR factorizations. Our contributions essentially consist of providing new CPU/GPU hybrid LU kernels, studying the impact on performance of the looking variants as well as the storage layout in presence of pivoting, tuning the kernels for two different machines composed of multiple recent NVIDIA Tesla S1070 (four GPUs total) and Fermi-based S2050 GPUs (three GPUs total), respectively. The hybrid tile LU asymptotically achieves 1 Tflop/s in single precision on both hardwares. The performance in double precision arithmetic reaches 500 Gflop/s on the Fermi-based system, twice faster than the old GPU generation of Tesla S1070. We also discuss the impact of the number of tiles on the numerical stability. We show that the numerical results of the tile LU factorization will be accurate enough for most applications as long as the computations are performed in double precision arithmetic. © 2011 IEEE.

  20. Enhanced single-stage laser-driven electron acceleration by self-controlled ionization injection.

    Science.gov (United States)

    Li, Song; Hafz, Nasr A M; Mirzaie, Mohammad; Sokollik, Thomas; Zeng, Ming; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-12-01

    We report on overall enhancement of a single-stage laser wakefield acceleration (LWFA) using the ionization injection in a mixture of 0.3% nitrogen gas in 99.7% helium gas. Upon the interaction of 30-TW, 30-fs laser pulses with a gas jet of the above gas mixture, >300 MeV electron beams were generated at a helium plasma densities of 3.3-8.5 × 10(18) cm(-3). Compared with the uncontrolled electron self-injection in pure helium gas jet, the ionization injection process due to the presence of ultra-low nitrogen concentrations appears to be self-controlled; it has led to the generation of electron beams with higher energies, higher charge, lower density threshold for trapping, and a narrower energy spread without dark current (low energy electrons) or multiple bunches. It is foreseen that further optimization of such a scheme is expected to bring the electron beam energy-spread down to 1%, making them suitable for driving ultra-compact free-electron lasers.

  1. Nanomedical science and laser-driven particle acceleration: promising approaches in the prethermal regime

    Science.gov (United States)

    Gauduel, Y. A.

    2017-05-01

    A major challenge of spatio-temporal radiation biomedicine concerns the understanding of biophysical events triggered by an initial energy deposition inside confined ionization tracks. This contribution deals with an interdisciplinary approach that concerns cutting-edge advances in real-time radiation events, considering the potentialities of innovating strategies based on ultrafast laser science, from femtosecond photon sources to advanced techniques of ultrafast TW laser-plasma accelerator. Recent advances of powerful TW laser sources ( 1019 W cm-2) and laser-plasma interactions providing ultra-short relativistic particle beams in the energy domain 5-200 MeV open promising opportunities for the development of high energy radiation femtochemistry (HERF) in the prethermal regime of secondary low-energy electrons and for the real-time imaging of radiation-induced biomolecular alterations at the nanoscopic scale. New developments would permit to correlate early radiation events triggered by ultrashort radiation sources with a molecular approach of Relative Biological Effectiveness (RBE). These emerging research developments are crucial to understand simultaneously, at the sub-picosecond and nanometric scales, the early consequences of ultra-short-pulsed radiation on biomolecular environments or integrated biological entities. This innovating approach would be applied to biomedical relevant concepts such as the emerging domain of real-time nanodosimetry for targeted pro-drug activation and pulsed radio-chimiotherapy of cancers.

  2. Laser Wakefield Acceleration Driven by a CO2 Laser (STELLA-LW) - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Wayne D

    2008-06-27

    The original goals of the Staged Electron Laser Acceleration – Laser Wakefield (STELLA-LW) program were to investigate two new methods for laser wakefield acceleration (LWFA). In pseudo-resonant LWFA (PR-LWFA), a laser pulse experiences nonlinear pulse steepening while traveling through the plasma. This steepening allows the laser pulse to generate wakefields even though the laser pulse length is too long for resonant LWFA to occur. For the conditions of this program, PR-LWFA requires a minimum laser peak power of 3 TW and a low plasma density (10^16 cm^-3). Seeded self-modulated LWFA (seeded SM-LWFA) combines LWFA with plasma wakefield acceleration (PWFA). An ultrashort (~100 fs) electron beam bunch acts as a seed in a plasma to form a wakefield via PWFA. This wakefield is subsequently amplified by the laser pulse through a self-modulated LWFA process. At least 1 TW laser power and, for a ~100-fs bunch, a plasma density ~10^17 cm^-3 are required. STELLA-LW was located on Beamline #1 at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). The ATF TW CO2 laser served as the driving laser beam for both methods. For PR-LWFA, a single bunch was to probe the wakefield produced by the laser beam. For seeded SM-LWFA, the ATF linac would produce two bunches, where the first would be the seed and the second would be the witness. A chicane would compress the first bunch to enable it to generate wakefields via PWFA. The plasma source was a short-length, gas-filled capillary discharge with the laser beam tightly focused in the center of the capillary, i.e., no laser guiding was used, in order to obtain the needed laser intensity. During the course of the program, several major changes had to be made. First, the ATF could not complete the upgrade of the CO2 laser to the 3 TW peak power needed for the PR-LWFA experiment. Therefore, the PR-LWFA experiment had to be abandoned leaving only the seeded SM-LWFA experiment. Second, the ATF discovered that the

  3. Dysregulated physiological stress systems and accelerated cellular aging

    NARCIS (Netherlands)

    Révész, D.; Verhoeven, J.; Milaneschi, Y.; de Geus, E.J.C.; Wolkowitz, O.M.; Penninx, B.W.J.H.

    2014-01-01

    Exposure to chronic stressors is associated with accelerated biological aging as indicated by reduced leukocyte telomere length (LTL). This impact could be because of chronic overactivation of the body's physiological stress systems. This study examined the associations between LTL and the immune

  4. Group decision support system for customer-driven product design

    Science.gov (United States)

    Lin, Zhihang; Chen, Hang; Chen, Kuen; Che, Ada

    2000-10-01

    This paper describes the work on the development of a group decision support system for customer driven product design. The customer driven is to develop products, which meet all customer requirements in whole life cycle of products. A process model of decision during product primary design is proposed to formulate the structured, semi-structured and unstructured decision problems. The framework for the decision support system is presented that integrated both advances in the group decision making and distributed artificial intelligent. The system consists of the product primary design tool kit and the collaborative platform with multi-agent structure. The collaborative platform of the system and the product primary design tool kit, including the VOC (Voice of Customer) tool, QFD (Quality Function Deployment) tool, the Conceptual design tool, Reliability analysis tool and the cost and profit forecasting tool, are indicated.

  5. Quantum Accelerators for High-performance Computing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Humble, Travis S. [ORNL; Britt, Keith A. [ORNL; Mohiyaddin, Fahd A. [ORNL

    2017-11-01

    We define some of the programming and system-level challenges facing the application of quantum processing to high-performance computing. Alongside barriers to physical integration, prominent differences in the execution of quantum and conventional programs challenges the intersection of these computational models. Following a brief overview of the state of the art, we discuss recent advances in programming and execution models for hybrid quantum-classical computing. We discuss a novel quantum-accelerator framework that uses specialized kernels to offload select workloads while integrating with existing computing infrastructure. We elaborate on the role of the host operating system to manage these unique accelerator resources, the prospects for deploying quantum modules, and the requirements placed on the language hierarchy connecting these different system components. We draw on recent advances in the modeling and simulation of quantum computing systems with the development of architectures for hybrid high-performance computing systems and the realization of software stacks for controlling quantum devices. Finally, we present simulation results that describe the expected system-level behavior of high-performance computing systems composed from compute nodes with quantum processing units. We describe performance for these hybrid systems in terms of time-to-solution, accuracy, and energy consumption, and we use simple application examples to estimate the performance advantage of quantum acceleration.

  6. Adiabatic perturbation theory and geometry of periodically-driven systems

    Science.gov (United States)

    Weinberg, Phillip; Bukov, Marin; D'Alessio, Luca; Polkovnikov, Anatoli; Vajna, Szabolcs; Kolodrubetz, Michael

    2017-05-01

    We give a systematic review of the adiabatic theorem and the leading non-adiabatic corrections in periodically-driven (Floquet) systems. These corrections have a two-fold origin: (i) conventional ones originating from the gradually changing Floquet Hamiltonian and (ii) corrections originating from changing the micro-motion operator. These corrections conspire to give a Hall-type linear response for non-stroboscopic (time-averaged) observables allowing one to measure the Berry curvature and the Chern number related to the Floquet Hamiltonian, thus extending these concepts to periodically-driven many-body systems. The non-zero Floquet Chern number allows one to realize a Thouless energy pump, where one can adiabatically add energy to the system in discrete units of the driving frequency. We discuss the validity of Floquet Adiabatic Perturbation Theory (FAPT) using five different models covering linear and non-linear few and many-particle systems. We argue that in interacting systems, even in the stable high-frequency regimes, FAPT breaks down at ultra slow ramp rates due to avoided crossings of photon resonances, not captured by the inverse-frequency expansion, leading to a counter-intuitive stronger heating at slower ramp rates. Nevertheless, large windows in the ramp rate are shown to exist for which the physics of interacting driven systems is well captured by FAPT.

  7. Accelerating translational research by clinically driven development of an informatics platform--a case study.

    Directory of Open Access Journals (Sweden)

    Imad Abugessaisa

    Full Text Available Translational medicine is becoming increasingly dependent upon data generated from health care, clinical research, and molecular investigations. This increasing rate of production and diversity in data has brought about several challenges, including the need to integrate fragmented databases, enable secondary use of patient clinical data from health care in clinical research, and to create information systems that clinicians and biomedical researchers can readily use. Our case study effectively integrates requirements from the clinical and biomedical researcher perspectives in a translational medicine setting. Our three principal achievements are (a a design of a user-friendly web-based system for management and integration of clinical and molecular databases, while adhering to proper de-identification and security measures; (b providing a real-world test of the system functionalities using clinical cohorts; and (c system integration with a clinical decision support system to demonstrate system interoperability. We engaged two active clinical cohorts, 747 psoriasis patients and 2001 rheumatoid arthritis patients, to demonstrate efficient query possibilities across the data sources, enable cohort stratification, extract variation in antibody patterns, study biomarker predictors of treatment response in RA patients, and to explore metabolic profiles of psoriasis patients. Finally, we demonstrated system interoperability by enabling integration with an established clinical decision support system in health care. To assure the usefulness and usability of the system, we followed two approaches. First, we created a graphical user interface supporting all user interactions. Secondly we carried out a system performance evaluation study where we measured the average response time in seconds for active users, http errors, and kilobits per second received and sent. The maximum response time was found to be 0.12 seconds; no server or client errors of any

  8. Controller synthesis for negative imaginary systems: a data driven approach

    KAUST Repository

    Mabrok, Mohamed

    2016-02-17

    The negative imaginary (NI) property occurs in many important applications. For instance, flexible structure systems with collocated force actuators and position sensors can be modelled as negative imaginary systems. In this study, a data-driven controller synthesis methodology for NI systems is presented. In this approach, measured frequency response data of the plant is used to construct the controller frequency response at every frequency by minimising a cost function. Then, this controller response is used to identify the controller transfer function using system identification methods. © The Institution of Engineering and Technology 2016.

  9. Low-charge, hard x-ray free electron laser driven with an X-band injector and accelerator

    Directory of Open Access Journals (Sweden)

    Yipeng Sun (孙一鹏

    2012-03-01

    Full Text Available After the successful operation of the Free Electron Laser in Hamburg (FLASH and the Linac Coherent Light Source (LCLS, soft and hard x-ray free electron lasers (FELs are being built, designed, or proposed at many accelerator laboratories. Acceleration employing lower frequency rf cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic rf system is employed to linearize the beam’s longitudinal phase space, which is nonlinearly chirped during the lower frequency rf acceleration process. In this paper, a hard x-ray FEL design using an all X-band accelerator at 11.424 GHz (from photocathode rf gun to linac end is presented, without the assistance of any harmonic rf linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient, and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (rms, low-charge (10 pC electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macroparticle 3D simulation employing several computer codes is presented in this paper, where space charge, wakefields, and incoherent and coherent synchrotron radiation effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low-charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters, which makes it possible to be built in places where only limited space is available.

  10. Electron linear accelerator system for natural rubber vulcanization

    Science.gov (United States)

    Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

    2017-09-01

    Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

  11. Electrodeless plasma acceleration system using rotating magnetic field method

    Directory of Open Access Journals (Sweden)

    T. Furukawa

    2017-11-01

    Full Text Available We have proposed Rotating Magnetic Field (RMF acceleration method as one of electrodeless plasma accelerations. In our experimental scheme, plasma generated by an rf (radio frequency antenna, is accelerated by RMF antennas, which consist of two-pair, opposed, facing coils, and these antennas are outside of a discharge tube. Therefore, there is no wear of electrodes, degrading the propulsion performance. Here, we will introduce our RMF acceleration system developed, including the experimental device, e.g., external antennas, a tapered quartz tube, a vacuum chamber, external magnets, and a pumping system. In addition, we can change RMF operation parameters (RMF applied current IRMF and RMF current phase difference ϕ, focusing on RMF current frequency fRMF by adjusting matching conditions of RMF, and investigate the dependencies on plasma parameters (electron density ne and ion velocity vi; e.g., higher increases of ne and vi (∼360 % and 55 %, respectively than previous experimental results were obtained by decreasing fRMF from 5 MHz to 0.7 MHz, whose RMF penetration condition was better according to Milroy’s expression. Moreover, time-varying component of RMF has been measured directly to survey the penetration condition experimentally.

  12. Electrodeless plasma acceleration system using rotating magnetic field method

    Science.gov (United States)

    Furukawa, T.; Takizawa, K.; Kuwahara, D.; Shinohara, S.

    2017-11-01

    We have proposed Rotating Magnetic Field (RMF) acceleration method as one of electrodeless plasma accelerations. In our experimental scheme, plasma generated by an rf (radio frequency) antenna, is accelerated by RMF antennas, which consist of two-pair, opposed, facing coils, and these antennas are outside of a discharge tube. Therefore, there is no wear of electrodes, degrading the propulsion performance. Here, we will introduce our RMF acceleration system developed, including the experimental device, e.g., external antennas, a tapered quartz tube, a vacuum chamber, external magnets, and a pumping system. In addition, we can change RMF operation parameters (RMF applied current IRMF and RMF current phase difference ϕ, focusing on RMF current frequency fRMF) by adjusting matching conditions of RMF, and investigate the dependencies on plasma parameters (electron density ne and ion velocity vi); e.g., higher increases of ne and vi (˜360 % and 55 %, respectively) than previous experimental results were obtained by decreasing fRMF from 5 MHz to 0.7 MHz, whose RMF penetration condition was better according to Milroy's expression. Moreover, time-varying component of RMF has been measured directly to survey the penetration condition experimentally.

  13. Sensitivity to Acceleration in the Human Early Visual System

    Directory of Open Access Journals (Sweden)

    Ryohei Nakayama

    2017-06-01

    Full Text Available It is widely believed that the human visual system is insensitive to acceleration in moving stimuli. This notion is supported by evidence that detection sensitivity for velocity modulation in moving stimuli is a lowpass function of the velocity modulation's temporal frequency. However, the lowpass function might be a mixture of detection by attention-based tracking and low-level mechanisms sensitive to acceleration. To revisit the issue of acceleration perception in relation to attentive tracking, we measured detection sensitivities for velocity modulations at various temporal frequencies (0.25–8 Hz by using drifting gratings within long or short spatial windows that make the tracking of grating easier or more difficult respectively. Results showed that modulation sensitivity is lowpass for gratings with long windows but bandpass for gratings with short windows (peak at ~1 Hz. Moreover, we found that lowpass sensitivity becomes bandpass when we removed observer attention by a concurrent letter identification task. An additional visual-search experiment showed that a target dot moving with a velocity modulation at relatively high temporal frequencies (~2–4 Hz was most easily detected among dots moving at various constant velocities. These results support the notion that high sensitivity to sluggish velocity modulation is a product of attentively tracking of moving stimuli and that the visual system is directly sensitive to accelerations and/or decelerations at the preattentive level.

  14. Strategies for mitigating the ionization-induced beam head erosion problem in an electron-beam-driven plasma wakefield accelerator

    Directory of Open Access Journals (Sweden)

    W. An

    2013-10-01

    Full Text Available Strategies for mitigating ionization-induced beam head erosion in an electron-beam-driven plasma wakefield accelerator (PWFA are explored when the plasma and the wake are both formed by the transverse electric field of the beam itself. Beam head erosion can occur in a preformed plasma because of a lack of focusing force from the wake at the rising edge (head of the beam due to the finite inertia of the electrons. When the plasma is produced by field ionization from the space charge field of the beam, the head erosion is significantly exacerbated due to the gradual recession (in the beam frame of the 100% ionization contour. Beam particles in front of the ionization front cannot be focused (guided causing them to expand as in vacuum. When they expand, the location of the ionization front recedes such that even more beam particles are completely unguided. Eventually this process terminates the wake formation prematurely, i.e., well before the beam is depleted of its energy. Ionization-induced head erosion can be mitigated by controlling the beam parameters (emittance, charge, and energy and/or the plasma conditions. In this paper we explore how the latter can be optimized so as to extend the beam propagation distance and thereby increase the energy gain. In particular we show that, by using a combination of the alkali atoms of the lowest practical ionization potential (Cs for plasma formation and a precursor laser pulse to generate a narrow plasma filament in front of the beam, the head erosion rate can be dramatically reduced. Simulation results show that in the upcoming “two-bunch PWFA experiments” on the FACET facility at SLAC national accelerator laboratory the energy gain of the trailing beam can be up to 10 times larger for the given parameters when employing these techniques. Comparison of the effect of beam head erosion in preformed and ionization produced plasmas is also presented.

  15. The Awful Truth About Zero-Gravity: Space Acceleration Measurement System; Orbital Acceleration Research Experiment

    Science.gov (United States)

    2002-01-01

    Earth's gravity holds the Shuttle in orbit, as it does satellites and the Moon. The apparent weightlessness experienced by astronauts and experiments on the Shuttle is a balancing act, the result of free-fall, or continuously falling around Earth. An easy way to visualize what is happening is with a thought experiment that Sir Isaac Newton did in 1686. Newton envisioned a mountain extending above Earth's atmosphere so that friction with the air would be eliminated. He imagined a cannon atop the mountain and aimed parallel to the ground. Firing the cannon propels the cannonball forward. At the same time, Earth's gravity pulls the cannonball down to the surface and eventual impact. Newton visualized using enough powder to just balance gravity so the cannonball would circle the Earth. Like the cannonball, objects orbiting Earth are in continuous free-fall, and it appears that gravity has been eliminated. Yet, that appearance is deceiving. Activities aboard the Shuttle generate a range of accelerations that have effects similar to those of gravity. The crew works and exercises. The main data relay antenna quivers 17 times per second to prevent 'stiction,' where parts stick then release with a jerk. Cooling pumps, air fans, and other systems add vibration. And traces of Earth's atmosphere, even 200 miles up, drag on the Shuttle. While imperceptible to us, these vibrations can have a profound impact on the commercial research and scientific experiments aboard the Shuttle. Measuring these forces is necessary so that researchers and scientists can see what may have affected their experiments when analyzing data. On STS-107 this service is provided by the Space Acceleration Measurement System for Free Flyers (SAMS-FF) and the Orbital Acceleration Research Experiment (OARE). Precision data from these two instruments will help scientists analyze data from their experiments and eliminate outside influences from the phenomena they are studying during the mission.

  16. Outcome-driven Evaluation Metrics for Treatment Recommendation Systems.

    Science.gov (United States)

    Mei, Jing; Liu, Haifeng; Li, Xiang; Yu, Yiqin; Xie, Guotong

    2015-01-01

    Treatment recommendation systems aim to providing clinical decision supports, e.g. with integration of Computerized Physician Order Entry (CPOE). One of the most significant issue is the quality of recommendations which needs to be quantified, before getting the acceptance from physicians. In computer science, such evaluations are typically performed by applying appropriate metrics that provides a comparison of different systems. However, a big challenge for evaluating treatment recommendation systems is that ground truth is only partially observed. In this paper, we propose an outcome-driven evaluation methodology, and present five metrics (i.e. precision, recall, accuracy, relative risk and odds ratio) with highlight of their statistic meanings in clinical context. The experimental results are based on the comparison of two well-developed treatment recommendation systems (one is knowledge-driven and based on clinical practice guidelines, while the other is data-driven and based on patient similarity analysis), using our proposed evaluation metrics. As a conclusion, physicians are less prone to comply with clinical guidelines, but once following guideline recommendations, it is much more likely to get good outcomes than not following.

  17. Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

    Science.gov (United States)

    Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A. D.; Scuderi, V.; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G. A. P.

    2016-07-01

    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here.

  18. Accelerate!

    Science.gov (United States)

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves.

  19. Asymptotics of work distributions in a stochastically driven system

    Science.gov (United States)

    Manikandan, Sreekanth K.; Krishnamurthy, Supriya

    2017-12-01

    We determine the asymptotic forms of work distributions at arbitrary times T, in a class of driven stochastic systems using a theory developed by Nickelsen and Engel (EN theory) [D. Nickelsen and A. Engel, Eur. Phys. J. B 82, 207 (2011)], which is based on the contraction principle of large deviation theory. In this paper, we extend the theory, previously applied in the context of deterministically driven systems, to a model in which the driving is stochastic. The models we study are described by overdamped Langevin equations and the work distributions in path integral form, are characterised by having quadratic augmented actions. We first illustrate EN theory, for a deterministically driven system - the breathing parabola model, and show that within its framework, the Crooks fluctuation theorem manifests itself as a reflection symmetry property of a certain characteristic polynomial, which also determines the exact moment-generating-function at arbitrary times. We then extend our analysis to a stochastically driven system, studied in references [S. Sabhapandit, EPL 89, 60003 (2010); A. Pal, S. Sabhapandit, Phys. Rev. E 87, 022138 (2013); G. Verley, C. Van den Broeck, M. Esposito, New J. Phys. 16, 095001 (2014)], for both equilibrium and non-equilibrium steady state initial distributions. In both cases we obtain new analytic solutions for the asymptotic forms of (dissipated) work distributions at arbitrary T. For dissipated work in the steady state, we compare the large T asymptotic behaviour of our solution to the functional form obtained in reference [New J. Phys. 16, 095001 (2014)]. In all cases, special emphasis is placed on the computation of the pre-exponential factor and the results show excellent agreement with numerical simulations. Our solutions are exact in the low noise (β → ∞) limit.

  20. Entanglement replication in driven dissipative many-body systems.

    Science.gov (United States)

    Zippilli, S; Paternostro, M; Adesso, G; Illuminati, F

    2013-01-25

    We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.

  1. The ORNL 25 MV tandem accelerator control system

    Science.gov (United States)

    Juras, Raymond C.; Biggerstaff, John A.; Hoglund, David E.

    1986-06-01

    The CAMAC-based control system for the 25 MV tandem electrostatic accelerator of the Holifield Heavy Ion Research Facility at Oak Ridge National Laboratory (ORNL) was specified by ORNL and built by the National Electrostatics Corporation. Two Perkin-Elmer 32-bit minicomputers are used in the system: a message switching computer and a supervisory computer. The message switching computer transmits and receives control information on six serial highways. This computer shares memory with the supervisory computer. Operator consoles are located on a serial highway; control is by means of a console CRT, trackball, and assignable shaft encoders and meters. Two identical consoles operate simultaneously: one is located in the tandem control room; the other is located in the cyclotron control room to facilitate operation during injection of tandem beams into the cyclotron or when beam lines under control of the cyclotron control system are used. The supervisory computer is used for accelerator parameter setup calculations, actual accelerator setup for new beams based on scaled, recorded parameters from previously run beams, and various other functions. The experience of nearly seven years of control system operation and improvements is discussed.

  2. Modeling pulse driven antenna systems with finite differences

    Science.gov (United States)

    Barth, Marvin; Pennock, Steve; Ziolkowski, Richard; McLeod, Robert

    1990-03-01

    The capability was developed of modeling the performance of general, pulse driven, antenna systems. The approach is to use TSAR, a three dimensional finite difference time domain (FDTD) code, to model the antenna structure and the surrounding near field environment. A far field project algorithm was used to obtain its far field response. Specifically, this algorithm utilizes the tangential electric and magnetic fields at a specified surface of the TSAR FDTD computational volume and calculates the resulting fields far from the equivalent magnetic and electric sources. This approach is illustrated by considering the TEB antenna system. The system is modeled with the code and the results are compared with anechoic chamber data.

  3. Keldysh field theory for driven open quantum systems.

    Science.gov (United States)

    Sieberer, L M; Buchhold, M; Diehl, S

    2016-09-01

    Recent experimental developments in diverse areas-ranging from cold atomic gases to light-driven semiconductors to microcavity arrays-move systems into the focus which are located on the interface of quantum optics, many-body physics and statistical mechanics. They share in common that coherent and driven-dissipative quantum dynamics occur on an equal footing, creating genuine non-equilibrium scenarios without immediate counterpart in equilibrium condensed matter physics. This concerns both their non-thermal stationary states and their many-body time evolution. It is a challenge to theory to identify novel instances of universal emergent macroscopic phenomena, which are tied unambiguously and in an observable way to the microscopic drive conditions. In this review, we discuss some recent results in this direction. Moreover, we provide a systematic introduction to the open system Keldysh functional integral approach, which is the proper technical tool to accomplish a merger of quantum optics and many-body physics, and leverages the power of modern quantum field theory to driven open quantum systems.

  4. Computational investigation of 99Mo, 89Sr, and 131I production rates in a subcritical UO2(NO32 aqueous solution reactor driven by a 30-MeV proton accelerator

    Directory of Open Access Journals (Sweden)

    Z. Gholamzadeh

    2015-12-01

    Full Text Available The use of subcritical aqueous homogenous reactors driven by accelerators presents an attractive alternative for producing 99Mo. In this method, the medical isotope production system itself is used to extract 99Mo or other radioisotopes so that there is no need to irradiate common targets. In addition, it can operate at much lower power compared to a traditional reactor to produce the same amount of 99Mo by irradiating targets. In this study, the neutronic performance and 99Mo, 89Sr, and 131I production capacity of a subcritical aqueous homogenous reactor fueled with low-enriched uranyl nitrate was evaluated using the MCNPX code. A proton accelerator with a maximum 30-MeV accelerating power was used to run the subcritical core. The computational results indicate a good potential for the modeled system to produce the radioisotopes under completely safe conditions because of the high negative reactivity coefficients of the modeled core. The results show that application of an optimized beam window material can increase the fission power of the aqueous nitrate fuel up to 80%. This accelerator-based procedure using low enriched uranium nitrate fuel to produce radioisotopes presents a potentially competitive alternative in comparison with the reactor-based or other accelerator-based methods. This system produces ∼1,500 Ci/wk (∼325 6-day Ci of 99Mo at the end of a cycle.

  5. Customizable software architectures in the accelerator control system environment

    CERN Document Server

    Mejuev, I; Kadokura, E

    2001-01-01

    Tailoring is further evolution of an application after deployment in order to adapt it to requirements that were not accounted for in the original design. End-user customization has been extensively researched in applied computer science from HCI and software engineering perspectives. Customization allows coping with flexibility requirements, decreasing maintenance and development costs of software products. In general, dynamic or diverse software requirements constitute the need for implementing end-user customization in computer systems. In accelerator physics research the factor of dynamic requirements is especially important, due to frequent software and hardware modifications resulting in correspondingly high upgrade and maintenance costs. We introduce the results of feasibility study on implementing end-user tailorability in the software for accelerator control system, considering the design and implementation of a distributed monitoring application for the 12 GeV KEK Proton Synchrotron as an example. T...

  6. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  7. SEU-tolerant IQ detection algorithm for LLRF accelerator system

    Science.gov (United States)

    Grecki, M.

    2007-08-01

    High-energy accelerators use RF field to accelerate charged particles. Measurements of effective field parameters (amplitude and phase) are tasks of great importance in these facilities. The RF signal is downconverted in frequency but keeping the information about amplitude and phase and then sampled in ADC. One of the several tasks for LLRF control system is to estimate the amplitude and phase (or I and Q components) of the RF signal. These parameters are further used in the control algorithm. The XFEL accelerator will be built using a single-tunnel concept. Therefore electronic devices (including LLRF control system) will be exposed to ionizing radiation, particularly to a neutron flux generating SEUs in digital circuits. The algorithms implemented in FPGA/DSP should therefore be SEU-tolerant. This paper presents the application of the WCC method to obtain immunity of IQ detection algorithm to SEUs. The VHDL implementation of this algorithm in Xilinx Virtex II Pro FPGA is presented, together with results of simulation proving the algorithm suitability for systems operating in the presence of SEUs.

  8. Maintenance of systemic immune functions prevents accelerated presbycusis.

    Science.gov (United States)

    Iwai, Hiroshi; Baba, Susumu; Omae, Mariko; Lee, Shinryu; Yamashita, Toshio; Ikehara, Susumu

    2008-05-07

    There is no effective therapy for progressive hearing loss such as presbycusis, the causes of which remain poorly understood because of the difficulty of separating genetic and environmental contributions. In the present study, we show that the age-related dysfunctions of the systemic immune system in an animal model of accelerated presbycusis (SAMP1, senescence-accelerated mouse P1) can be corrected by allogeneic bone marrow transplantation (BMT). We also demonstrate that this presbycusis can be prevented; BMT protects the recipients from age-related hearing impairment and the degeneration of spiral ganglion cells (SGCs) as well as the dysfunctions of T lymphocytes, which have a close relation to immune senescence. No donor cells are infiltrated to the spiral ganglia, confirming that this experimental system using BMT is connected to the systemic immune system and does not contribute to transdifferentiation or fusion by donor hematopoietic stem cells (HSCs), or to the direct maintenance of ganglion cells by locally infiltrated donor immunocompetent cells. Therefore, another procedure which attempts to prevent the age-related dysfunctions of the recipient immune system is the inoculation of syngeneic splenocytes from young donors. These mice show no development of hearing loss, compared with the recipient mice with inoculation of saline or splenocytes from old donors. Our studies on the relationship between age-related systemic immune dysfunctions and neurodegeneration mechanisms open up new avenues of treatment for presbycusis, for which there is no effective therapy.

  9. Data-Driven Predictive Direct Load Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Knudsen, Torben; Wisniewski, Rafal

    2015-01-01

    A predictive control using subspace identification is applied for the smart grid integration of refrigeration systems under a direct load control scheme. A realistic demand response scenario based on regulation of the electrical power consumption is considered. A receding horizon optimal control...... is proposed to fulfil two important objectives: to secure high coefficient of performance and to participate in power consumption management. Moreover, a new method for design of input signals for system identification is put forward. The control method is fully data driven without an explicit use of model...

  10. Electromagnetic Properties Analysis on Hybrid-driven System of Electromagnetic Motor

    Science.gov (United States)

    Zhao, Jingbo; Han, Bingyuan; Bei, Shaoyi

    2018-01-01

    The hybrid-driven system made of permanent-and electromagnets applied in the electromagnetic motor was analyzed, equivalent magnetic circuit was used to establish the mathematical models of hybrid-driven system, based on the models of hybrid-driven system, the air gap flux, air-gap magnetic flux density, electromagnetic force was proposed. Taking the air-gap magnetic flux density and electromagnetic force as main research object, the hybrid-driven system was researched. Electromagnetic properties of hybrid-driven system with different working current modes is studied preliminary. The results shown that analysis based on hybrid-driven system can improve the air-gap magnetic flux density and electromagnetic force more effectively and can also guarantee the output stability, the effectiveness and feasibility of the hybrid-driven system are verified, which proved theoretical basis for the design of hybrid-driven system.

  11. Accelerated maximum likelihood parameter estimation for stochastic biochemical systems

    Directory of Open Access Journals (Sweden)

    Daigle Bernie J

    2012-05-01

    Full Text Available Abstract Background A prerequisite for the mechanistic simulation of a biochemical system is detailed knowledge of its kinetic parameters. Despite recent experimental advances, the estimation of unknown parameter values from observed data is still a bottleneck for obtaining accurate simulation results. Many methods exist for parameter estimation in deterministic biochemical systems; methods for discrete stochastic systems are less well developed. Given the probabilistic nature of stochastic biochemical models, a natural approach is to choose parameter values that maximize the probability of the observed data with respect to the unknown parameters, a.k.a. the maximum likelihood parameter estimates (MLEs. MLE computation for all but the simplest models requires the simulation of many system trajectories that are consistent with experimental data. For models with unknown parameters, this presents a computational challenge, as the generation of consistent trajectories can be an extremely rare occurrence. Results We have developed Monte Carlo Expectation-Maximization with Modified Cross-Entropy Method (MCEM2: an accelerated method for calculating MLEs that combines advances in rare event simulation with a computationally efficient version of the Monte Carlo expectation-maximization (MCEM algorithm. Our method requires no prior knowledge regarding parameter values, and it automatically provides a multivariate parameter uncertainty estimate. We applied the method to five stochastic systems of increasing complexity, progressing from an analytically tractable pure-birth model to a computationally demanding model of yeast-polarization. Our results demonstrate that MCEM2 substantially accelerates MLE computation on all tested models when compared to a stand-alone version of MCEM. Additionally, we show how our method identifies parameter values for certain classes of models more accurately than two recently proposed computationally efficient methods

  12. Microgravity Acceleration Measurement System (MAMS) Flight Configuration Verification and Status

    Science.gov (United States)

    Wagar, William

    2000-01-01

    The Microgravity Acceleration Measurement System (MAMS) is a precision spaceflight instrument designed to measure and characterize the microgravity environment existing in the US Lab Module of the International Space Station. Both vibratory and quasi-steady triaxial acceleration data are acquired and provided to an Ethernet data link. The MAMS Double Mid-Deck Locker (DMDL) EXPRESS Rack payload meets all the ISS IDD and ICD interface requirements as discussed in the paper which also presents flight configuration illustrations. The overall MAMS sensor and data acquisition performance and verification data are presented in addition to a discussion of the Command and Data Handling features implemented via the ISS, downlink and the GRC Telescience Center displays.

  13. A RADIANT AIR-CONDITIONING SYSTEM USING SOLAR-DRIVEN

    Directory of Open Access Journals (Sweden)

    S. A. ABDALLA

    2006-12-01

    Full Text Available Every air-conditioning system needs some fresh air to provide adequate ventilation air required to remove moisture, gases like ammonia and hydrogen sulphide, disease organisms, and heat from occupied spaces. However, natural ventilation is difficult to control because urban areas outside air is often polluted and cannot be supplied to inner spaces before being filtered. Besides the high electrical demand of refrigerant compression units used by most air-conditioning systems, and fans used to transport the cool air through the thermal distribution system draw a significant amount of electrical energy in comparison with electrical energy used by the building thermal conditioning systems. Part of this electricity heats the cooled air; thereby add to the internal thermal cooling peak load. In addition, refrigerant compression has both direct and indirect negative effects on the environment on both local and global scales. In seeking for innovative air-conditioning systems that maintain and improve indoor air quality under potentially more demanding performance criteria without increasing environmental impact, this paper presents radiant air-conditioning system which uses a solar-driven liquid desiccant evaporative cooler. The paper describes the proposed solar-driven liquid desiccant evaporative cooling system and the method used for investigating its performance in providing cold water for a radiant air-conditioning system in Khartoum (Central Sudan. The results of the investigation show that the system can operate in humid as well as dry climates and that employing such a system reduces air-conditioning peak electrical demands as compared to vapour compression systems.

  14. Renewable energy credit driven wind power growth for system reliability

    Energy Technology Data Exchange (ETDEWEB)

    Karki, Rajesh [Power System Research Group, Department of Electrical Engineering, University of Saskatchewan, 57 Campus Dr., Saskatoon, Sask., S7N 5A9 (Canada)

    2007-05-15

    Environmental concerns over electric power generation from conventional sources has led to widespread public support for renewable energy sources. Governments throughout the world have responded by providing various forms of financial incentives to promote power generation from renewable energy sources. The rapid growth of wind power since the last decade has primarily been driven by governmental subsidies. Long-term growth of wind power should, however, be driven by sustainable market mechanisms. A potential solution is to recognize monetary values to the environmental benefits from renewable energy sources, and to specify targets for their growth. The environmental benefits from wind sources can be leveraged to allow market competition of these sources with the less costly conventional generating sources. A probabilistic method to evaluate the impact of renewable energy credit and wind penetration level on the cost and adequacy of power generating systems is presented in this paper. The technique incorporates reliability and economic analysis and is applied to a published test system to illustrate the results and their influence on key system variables. The paper provides useful information to system planners and policy makers on wind energy application in electric power systems. (author)

  15. Traffic and related self-driven many-particle systems

    Science.gov (United States)

    Helbing, Dirk

    2001-10-01

    Since the subject of traffic dynamics has captured the interest of physicists, many surprising effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by ``phantom traffic jams'' even though drivers all like to drive fast? What are the mechanisms behind stop-and-go traffic? Why are there several different kinds of congestion, and how are they related? Why do most traffic jams occur considerably before the road capacity is reached? Can a temporary reduction in the volume of traffic cause a lasting traffic jam? Under which conditions can speed limits speed up traffic? Why do pedestrians moving in opposite directions normally organize into lanes, while similar systems ``freeze by heating''? All of these questions have been answered by applying and extending methods from statistical physics and nonlinear dynamics to self-driven many-particle systems. This article considers the empirical data and then reviews the main approaches to modeling pedestrian and vehicle traffic. These include microscopic (particle-based), mesoscopic (gas-kinetic), and macroscopic (fluid-dynamic) models. Attention is also paid to the formulation of a micro-macro link, to aspects of universality, and to other unifying concepts, such as a general modeling framework for self-driven many-particle systems, including spin systems. While the primary focus is upon vehicle and pedestrian traffic, applications to biological or socio-economic systems such as bacterial colonies, flocks of birds, panics, and stock market dynamics are touched upon as well.

  16. Advances in Optimizing Weather Driven Electric Power Systems.

    Science.gov (United States)

    Clack, C.; MacDonald, A. E.; Alexander, A.; Dunbar, A. D.; Xie, Y.; Wilczak, J. M.

    2014-12-01

    The importance of weather-driven renewable energies for the United States (and global) energy portfolio is growing. The main perceived problems with weather-driven renewable energies are their intermittent nature, low power density, and high costs. The National Energy with Weather System Simulator (NEWS) is a mathematical optimization tool that allows the construction of weather-driven energy sources that will work in harmony with the needs of the system. For example, it will match the electric load, reduce variability, decrease costs, and abate carbon emissions. One important test run included existing US carbon-free power sources, natural gas power when needed, and a High Voltage Direct Current power transmission network. This study shows that the costs and carbon emissions from an optimally designed national system decrease with geographic size. It shows that with achievable estimates of wind and solar generation costs, that the US could decrease its carbon emissions by up to 80% by the early 2030s, without an increase in electric costs. The key requirement would be a 48 state network of HVDC transmission, creating a national market for electricity not possible in the current AC grid. These results were found without the need for storage. Further, we tested the effect of changing natural gas fuel prices on the optimal configuration of the national electric power system. Another test that was carried out was an extension to global regions. The extension study shows that the same properties found in the US study extend to the most populous regions of the planet. The extra test is a simplified version of the US study, and is where much more research can be carried out. We compare our results to other model results.

  17. Large high-vacuum systems for CERN accelerators

    Science.gov (United States)

    Strubin, P.

    2008-05-01

    CERN operated over the more than 50 years of its existence particle accelerators and storage rings ranging from a few tens of metre to 27 km, the size of its latest project, the Large Hadron Collider (LHC) which is under construction and will be started in 2008. The challenges began with the Intersection Storage Rings (ISR) in the seventies. With a beam pipe length of 2 × 1 km, this accelerator required innovative solutions like bake-out and glow discharge to achieve the required static vacuum level, fight against beam-induced pressure increases and cancel beam neutralisation by trapped electrons. The vacuum system of the Large Electron Positron (LEP) storage ring (in operation between 1989 and 2001) of a total length of 27 km had to cope with very high levels of synchrotron power. The beam vacuum system of LHC (2 × 27 km) integrates some parts at 1.9 K and others at room temperature and will also have to cope with dynamic effects. In addition to the beam vacuum system, LHC requires insulation vacuum for the superconducting magnets and the helium distribution line. Whereas the required pressure is not very low, the leak detection and localisation is significantly more demanding for the insulation vacuum than for the beam vacuum because of the large volumes and the thermal insulation. When the size of an accelerator grows, the difficulties are not only to get a clean and leak tight vacuum system, but also to be able to measure reliably pressure or gas composition over long distances. Furthermore, in the case of LHC the integration of the beam vacuum system was particularly difficult because of the complexity induced by a superconducting magnet scheme and the reduced space available for the beam pipes. Planning and logistics aspects during installation, including the usage of mobile pumping and diagnostic means, were much more difficult to manage in LHC than in previous projects.

  18. Status and Future Developments in Large Accelerator Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karen S. White

    2006-10-31

    Over the years, accelerator control systems have evolved from small hardwired systems to complex computer controlled systems with many types of graphical user interfaces and electronic data processing. Today's control systems often include multiple software layers, hundreds of distributed processors, and hundreds of thousands of lines of code. While it is clear that the next generation of accelerators will require much bigger control systems, they will also need better systems. Advances in technology will be needed to ensure the network bandwidth and CPU power can provide reasonable update rates and support the requisite timing systems. Beyond the scaling problem, next generation systems face additional challenges due to growing cyber security threats and the likelihood that some degree of remote development and operation will be required. With a large number of components, the need for high reliability increases and commercial solutions can play a key role towards this goal. Future control systems will operate more complex machines and need to present a well integrated, interoperable set of tools with a high degree of automation. Consistency of data presentation and exception handling will contribute to efficient operations. From the development perspective, engineers will need to provide integrated data management in the beginning of the project and build adaptive software components around a central data repository. This will make the system maintainable and ensure consistency throughout the inevitable changes during the machine lifetime. Additionally, such a large project will require professional project management and disciplined use of well-defined engineering processes. Distributed project teams will make the use of standards, formal requirements and design and configuration control vital. Success in building the control system of the future may hinge on how well we integrate commercial components and learn from best practices used in other industries.

  19. Proposed Physics Experiments for Laser-Driven Electron Linear Acceleration in a Dielectric Loaded Vacuum, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Byer, Robert L. [Stanford Univ., CA (United States). Dept. of Applied Physics. Edward L. Ginzton Lab.

    2016-07-08

    This final report summarizes the last three years of research on the development of advanced linear electron accelerators that utilize dielectric wave-guide vacuum channels pumped by high energy laser fields to accelerate beams of electrons.

  20. Kinetics and thermodynamics of a driven open quantum system

    Science.gov (United States)

    Thingna, Juzar; Barra, Felipe; Esposito, Massimiliano

    2017-11-01

    Redfield theory provides a closed kinetic description of a quantum system in weak contact with a very dense reservoir. Landau-Zener theory does the same for a time-dependent driven system in contact with a sparse reservoir. Using a simple model, we analyze the validity of these two theories by comparing their predictions with exact numerical results. We show that despite their a priori different range of validity, these two descriptions can give rise to an identical quantum master equation. Both theories can be used for a nonequilibrium thermodynamic description, which we show is consistent with exact thermodynamic identities evaluated in the full system-reservoir space. We emphasize the importance of properly accounting for the system-reservoir interaction energy and of operating in regimes where the reservoir can be considered as close to ideal.

  1. Global Accelerator Network, Control Systems And Beam Diagnostics

    CERN Document Server

    Raich, U

    2003-01-01

    Falling funds force all accelerator centers to look for new sources of financing and for the most efficient way of implementing new projects. This very often leads to collaborations between institutes scattered around the globe, a problem well known to big high energy physics experiments. The collaborations working on big detectors e.g. for LHC started thinking about detector acquisition and control systems which can be remotely used from their respective home institutes with minimal support on the spot. This idea was taken up by A. Wagner from DESY for the TESLA machine, who proposed the “Global Accelerator Network” (GAN) enabling users from around the world to run an accelerator remotely. Questions around this subject that immediately come to mind Is the GAN only relevant to big labs ? Or is it reasonable e.g. for operators or engineers in charge to do certain manipulations from home? Are our instruments ready for the GAN? Does the fact of being “GAN ready” increa...

  2. Data driven uncertainty evaluation for complex engineered system design

    Science.gov (United States)

    Liu, Boyuan; Huang, Shuangxi; Fan, Wenhui; Xiao, Tianyuan; Humann, James; Lai, Yuyang; Jin, Yan

    2016-09-01

    Complex engineered systems are often difficult to analyze and design due to the tangled interdependencies among their subsystems and components. Conventional design methods often need exact modeling or accurate structure decomposition, which limits their practical application. The rapid expansion of data makes utilizing data to guide and improve system design indispensable in practical engineering. In this paper, a data driven uncertainty evaluation approach is proposed to support the design of complex engineered systems. The core of the approach is a data-mining based uncertainty evaluation method that predicts the uncertainty level of a specific system design by means of analyzing association relations along different system attributes and synthesizing the information entropy of the covered attribute areas, and a quantitative measure of system uncertainty can be obtained accordingly. Monte Carlo simulation is introduced to get the uncertainty extrema, and the possible data distributions under different situations is discussed in detail. The uncertainty values can be normalized using the simulation results and the values can be used to evaluate different system designs. A prototype system is established, and two case studies have been carried out. The case of an inverted pendulum system validates the effectiveness of the proposed method, and the case of an oil sump design shows the practicability when two or more design plans need to be compared. This research can be used to evaluate the uncertainty of complex engineered systems completely relying on data, and is ideally suited for plan selection and performance analysis in system design.

  3. Model-driven dependability assessment of software systems

    CERN Document Server

    Bernardi, Simona; Petriu, Dorina C

    2013-01-01

    In this book, the authors present cutting-edge model-driven techniques for modeling and analysis of software dependability. Most of them are based on the use of UML as software specification language. From the software system specification point of view, such techniques exploit the standard extension mechanisms of UML (i.e., UML profiling). UML profiles enable software engineers to add non-functional properties to the software model, in addition to the functional ones. The authors detail the state of the art on UML profile proposals for dependability specification and rigorously describe the t

  4. Steam Driven Triple Effect Absorption Solar Cooling System

    OpenAIRE

    Yabase, Hajime; Makita, Kazuyuki

    2012-01-01

    The authors propose a solar cooling system employing a steam-driven triple effect absorption chiller as a new technique for saving CO2 emission in the air conditioning field. The absorption chiller is a cooling machine using thermal energy as a drive source, and it is ideal for utilizing solar heat. In addition, by employing a triple effect absorption chiller of high efficiency, a high energy saving effect and a significant CO2 saving effect can be expected. As a result of studies, it has bee...

  5. System on chip module configured for event-driven architecture

    Science.gov (United States)

    Robbins, Kevin; Brady, Charles E.; Ashlock, Tad A.

    2017-10-17

    A system on chip (SoC) module is described herein, wherein the SoC modules comprise a processor subsystem and a hardware logic subsystem. The processor subsystem and hardware logic subsystem are in communication with one another, and transmit event messages between one another. The processor subsystem executes software actors, while the hardware logic subsystem includes hardware actors, the software actors and hardware actors conform to an event-driven architecture, such that the software actors receive and generate event messages and the hardware actors receive and generate event messages.

  6. A Quality-Driven Methodology for Information Systems Integration

    Directory of Open Access Journals (Sweden)

    Iyad Zikra

    2017-10-01

    Full Text Available Information systems integration is an essential instrument for organizations to attain advantage in today’s growing and fast changing business and technology landscapes. Integration solutions generate added value by combining the functionality and services of heterogeneous and diverse systems. Existing integration environments tend to rely heavily on technical, platform-dependent skills. Consequently, the solutions that they enable are not optimally aligned with the envisioned business goals of the organization. Furthermore, the gap between the goals and the solutions complicates the task of evaluating the quality of integration solutions. To address these challenges, we propose a quality-driven, model-driven methodology for designing and developing integration solutions. The methodology spans organizational and systems design details, providing a holistic view of the integration solution and its underlying business goals. A multi-view meta-model provides the basis for the integration design. Quality factors that affect various aspects of the integration solution guide and inform the progress of the methodology. An example business case is presented to demonstrate the application of the methodology.

  7. Preparing Accelerator Systems for the RHIC Sextant Commissioning

    Science.gov (United States)

    Trbojevic, D.; Pilat, F.; Ahrens, L.; Barton, D.; Clifford, T.; Connoly, R.; Fischer, W.; Harrison, M.; Mackay, W.; Olsen, B.; Peggs, S.; Satogata, T.; Tepikian, S.; Thompson, P.; Trahern, C.; Witkover, R.

    1997-05-01

    The Relativistic Heavy Ion Collider (RHIC) construction is progressing steadily towards the beginning of the 1999 when beams will first be circulated in both collider rings. One of the major tests of the RHIC project is the commissioning of the first sextant with gold ion beams. This is a report on the preparation of the RHIC accelerator systems during the first sextant test, including beam position monitors, timing, injection correction through the magnetic septum and kickers, current transformers, ``flags'' and the ionization beam profile monitors, beam loss monitors, beam and quench permit link system, power supply controls, and the CYBASE data base system. The software and hardware development and coordination of the different systems before commissioning were regularly checked during bi-weekly, and (later) weekly, progress report meetings.

  8. Preparing Accelerator Systems for the RHIC Sextant Commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pilat, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ahrens, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Barton, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Clifford, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Connoly, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); HaJ.Tison, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); MacKay, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Olsen, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Satogata, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Thompson, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trahern, C. G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Witkover, R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    1997-05-12

    The Relativistic Heavy Ion Collider (RHIC) construction is progressing steadily towards completion in 1999 when beams will circulate in both collider rings. One of the major tests of the RHIC project was the commissioning of the first sextant with gold ion beams in early 1997. This is a report on preparation of the RHIC accelerator systems for the first sextant test. It includes beam position monitors, timing, injection correction through the magnetic septum and kickers, current transformers, "flags" and the ionization beam profile monitors, beam loss monitors, beam and quench permit link system, power supply controls, and the configuration database system. The software and hardware development and coordination of the different systems before commissioning were regularly checked during bi-weekly, and (later) weekly, progress report meetings.

  9. Heat Driven Cooling in District Energy Systems; Vaermedriven Kyla

    Energy Technology Data Exchange (ETDEWEB)

    Rydstrand, Magnus; Martin, Viktoria; Westermark, Mats [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2004-07-01

    high costs. However heat sinks are unavoidable from a system perspective and there are potential cost savings since a low-pressure steam turbines will not be required if heat driven cooling is implemented. The fuel utilization for some technologies (not necessarily the best technology) was evaluated in two different scenarios: 1) with electricity production from coal; and 2) with electricity production from natural gas. It is shown in the scenarios that the heat driven cooling technologies give lower fuel consumption as compared producing electricity as an intermediate product before cooling is produced. Further it should be noted that electricity is produced, not consumed, if heat is used directly for the production of cooling. We claim that cost effective solutions for district heat driven chillers and/or combined production of electricity and district cooling can be found in all climates with high enough density of heating and cooling demands. It was found that district heat driven chillers can be very energy efficient in warm and humid climates since desiccant systems are an effective way of handling latent cooling loads. In dry climates, with low latent loads, water distributed cooling has a large potential and absorption cooling will give high fuel utilization seen from a system perspective. In climates where water shortage is a problem it is possible that the temperature lift of the conventional absorption chiller has to be increased in order to be able to use dry cooling towers. The temperature lift can be increased by changing the chiller design or by using a different working pair. Heat driven cooling can be integrated into an energy system in different ways. In USA and Japan, district heating is not well developed. Instead small, distributed combined heat and power (CHP) plants with high exhaust temperatures are widespread. Cooling is often produced, in these regions, through absorption cooling (using heat from CHP) or compression chillers depending on

  10. Fluctuation theorem in driven nonthermal systems with quenched disorder

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, C J [Los Alamos National Laboratory; Drocco, J A [PRINCETON UNIV.

    2009-01-01

    We demonstrate that the fluctuation theorem of Evans and Searles can be used to characterize the class of dynamics that arises in nonthermal systems of collectively interacting particles driven over random quenched disorder. By observing the frequency of entropy-destroying trajectories, we show that there are specific dynamical regimes near depinning in which this theorem holds. Hence the fluctuation theorem can be used to characterize a significantly wider class of non-equilibrium systems than previously considered. We discuss how the fluctuation theorem could be tested in specific systems where noisy dynamics appear at the transition from a pinned to a moving phase such as in vortices in type-II superconductors, magnetic domain walls, and dislocation dynamics.

  11. Data-driven system to predict academic grades and dropout

    Science.gov (United States)

    Rovira, Sergi; Puertas, Eloi

    2017-01-01

    Nowadays, the role of a tutor is more important than ever to prevent students dropout and improve their academic performance. This work proposes a data-driven system to extract relevant information hidden in the student academic data and, thus, help tutors to offer their pupils a more proactive personal guidance. In particular, our system, based on machine learning techniques, makes predictions of dropout intention and courses grades of students, as well as personalized course recommendations. Moreover, we present different visualizations which help in the interpretation of the results. In the experimental validation, we show that the system obtains promising results with data from the degree studies in Law, Computer Science and Mathematics of the Universitat de Barcelona. PMID:28196078

  12. Accelerator technology for the Los Alamos ATW (accelerator transmutation of nuclear waste) system

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.P.

    1991-01-01

    The Los Alamos concept for accelerator transmutation of nuclear waste (ATW) employs a high-power proton linear accelerator to generate intense fluxes of thermal neutrons (>10{sup 16} n/cm{sup 2}-s) through spallation on a lead-bismuth target. The nominal beam energy for an ATW accelerator is 1.6 GeV, with average current requirements ranging from 250 mA to 30 mA, depending on application specifics. A recent study of accelerator production of tritium (APT) led to the development of a detailed point design for a 1.6 GeV, 250 mA cw proton linac. The accelerator design was reviewed by the Energy Research Advisory Board (ERAB) and found to be technically sound. The Panel concluded that linac of this power level could now be implemented within the existing technology base, given an adequate component development program and an integrated engineering demonstration of the front end.

  13. STUXNET and the Impact on Accelerator Control Systems

    CERN Document Server

    Lüders, S

    2011-01-01

    2010 has seen wide news coverage of a new kind of computer attack, named "Stuxnet", targeting control systems. Due to its level of sophistication, it is widely acknowledged that this attack marks the very first case of a cyber-war of one country against the industrial infrastructure of another, although there is still much speculation about the details. Worse yet, experts recognize that Stuxnet might just be the beginning and that similar attacks, eventually with much less sophistication, but with much more collateral damage, can be expected in the years to come. Stuxnet was targeting a special model of the Siemens 400 PLC series. Similar modules are also deployed for accelerator controls like the LHC cryogenics or vacuum systems as well as the detector control systems in LHC experiments. Therefore, the aim of this presentation is to give an insight into what this new attack does and why it is deemed to be special. In particular, the potential impact on accelerator and experiment control sys...

  14. Novel Approach to Linear Accelerator Superconducting Magnet System

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, Vladimir; /Fermilab

    2011-11-28

    Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.

  15. Order and Symmetry Breaking in the Fluctuations of Driven Systems

    Science.gov (United States)

    Tizón-Escamilla, N.; Pérez-Espigares, C.; Garrido, P. L.; Hurtado, P. I.

    2017-09-01

    Dynamical phase transitions (DPTs) in the space of trajectories are one of the most intriguing phenomena of nonequilibrium physics, but their nature in realistic high-dimensional systems remains puzzling. Here we observe for the first time a DPT in the current vector statistics of an archetypal two-dimensional (2D) driven diffusive system and characterize its properties using the macroscopic fluctuation theory. The complex interplay among the external field, anisotropy, and vector currents in 2D leads to a rich phase diagram, with different symmetry-broken fluctuation phases separated by lines of first- and second-order DPTs. Remarkably, different types of 1D order in the form of jammed density waves emerge to hinder transport for low-current fluctuations, revealing a connection between rare events and self-organized structures which enhance their probability.

  16. Dynamical response theory for driven-dissipative quantum systems

    Science.gov (United States)

    Campos Venuti, Lorenzo; Zanardi, Paolo

    2016-03-01

    We discuss dynamical response theory of driven-dissipative quantum systems described by Markovian master equations generating semigroups of maps. In this setting thermal equilibrium states are replaced by nonequilibrium steady states, and dissipative perturbations are considered in addition to the Hamiltonian ones. We derive explicit expressions for the linear dynamical response functions for generalized dephasing channels and for Davies thermalizing generators. We introduce the notion of maximal harmonic response and compute it exactly for a single-qubit channel. Finally, we analyze linear response near dynamical phase transitions in quasifree open quantum systems. It is found that the effect of the dynamical phase transition shows up in a peak at the edge of the spectrum in the imaginary part of the dynamical response function.

  17. Computational dynamics of acoustically-driven microsphere systems

    CERN Document Server

    Glosser, Connor A; Dault, Daniel L; Piermarocchi, Carlo; Shanker, Balasubramaniam

    2015-01-01

    We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the inter-particle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of non-dissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities, and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation ...

  18. Accelerated Aging System for Prognostics of Power Semiconductor Devices

    Science.gov (United States)

    Celaya, Jose R.; Vashchenko, Vladislav; Wysocki, Philip; Saha, Sankalita

    2010-01-01

    Prognostics is an engineering discipline that focuses on estimation of the health state of a component and the prediction of its remaining useful life (RUL) before failure. Health state estimation is based on actual conditions and it is fundamental for the prediction of RUL under anticipated future usage. Failure of electronic devices is of great concern as future aircraft will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. Therefore, development of prognostics solutions for electronics is of key importance. This paper presents an accelerated aging system for gate-controlled power transistors. This system allows for the understanding of the effects of failure mechanisms, and the identification of leading indicators of failure which are essential in the development of physics-based degradation models and RUL prediction. In particular, this system isolates electrical overstress from thermal overstress. Also, this system allows for a precise control of internal temperatures, enabling the exploration of intrinsic failure mechanisms not related to the device packaging. By controlling the temperature within safe operation levels of the device, accelerated aging is induced by electrical overstress only, avoiding the generation of thermal cycles. The temperature is controlled by active thermal-electric units. Several electrical and thermal signals are measured in-situ and recorded for further analysis in the identification of leading indicators of failures. This system, therefore, provides a unique capability in the exploration of different failure mechanisms and the identification of precursors of failure that can be used to provide a health management solution for electronic devices.

  19. Loss of Egr1, a human del5q gene, accelerates BCR-ABL driven chronic myelogenous leukemia

    Science.gov (United States)

    Maifrede, Silvia; Magimaidas, Andrew; Sha, Xiaojin; Mukherjee, Kaushiki; Liebermann, Dan A.; Hoffman, Barbara

    2017-01-01

    There is substantial evidence that early growth response-1 (Egr1) gene, a zinc-finger transcription factor, behaves as a tumor suppressor in leukemia. This includes reports from this laboratory that constitutive Egr1 overrides leukemia conferred by deregulated c-Myc or E2F-1 in the M1 myeloid leukemic cell line by promoting differentiation. To investigate the effect of Egr1 on the initiation and progression of Chronic Myelogenous Leukemia (CML), lethally irradiated syngeneic wild type mice were reconstituted with bone marrow (BM) from either wild type or Egr1 null mice transduced with a 210-kD BCR-ABL-expressing MSCV-retrovirus (bone marrow transplantation {BMT}). Loss of Egr1 was observed to accelerate the development of BCR-ABL driven leukemia in recipient mice, resulting in the development of a more aggressive disease, a significantly shortened median survival time, and increased BCR-ABL expressing leukemic stem/progenitor cells (GFP+Lin-cKit+Sca+). Egr1 deficient progenitors expressing BCR-ABL exhibited decreased apoptosis, and increased cell viability and proliferation relative to WT counterparts. Secondary BMT of BCR-ABL BM revealed that loss of Egr1 resulted in enrichment of LSCs, consistent with shorter survival time and more aggressive disease of these mice compared to WT counterparts. Furthermore, serial re-plating colony assays indicated that loss of Egr1 increased self-renewal ability of BCR-ABL expressing BM. These novel findings on the tumor suppressor role of Egr1 in CML provide the impetus to study the effect of altering Egr1 expression in AML, where the overall five year survival rate remains low. The effect of loss of Egr1 in CML could reflect its established functions in normal hematopoiesis, maintaining quiescence of HSCs and driving terminal differentiation to the monocyte/macrophage lineage. Gain of function studies should validate these conclusions and provide further rationale for increased Egr1 as a therapeutic target in AML. PMID:29050203

  20. CERN Open Days 2013, Point 6: Accelerator Systems

    CERN Document Server

    CERN Photolab

    2013-01-01

    Stand description: Each beam of protons that races around the Large Hadron Collider can contain as much energy as a French TGV train travelling at 150 km/hour.  When it's time to shut the machine down, the Beam Dump System ensures that this energy is safely dissipated. In the tunnel at Point 6 you will be able to see the devices which form part of this system, as well as the blue LHC dipole magnets curving away into the distance. On surface no restricted access  On the surface, you can explore a fascinating exhibition of equipment used in CERN's accelerators, with CERN engineers and physicists on hand all day to answer your questions. You will also see one of the cryogenics installations which keep the LHC at just few degrees above absolute zero and you can find out about the measures CERN has put in place to ensure safety and protect the environment.

  1. Two coupled, driven Ising spin systems working as an engine

    Science.gov (United States)

    Basu, Debarshi; Nandi, Joydip; Jayannavar, A. M.; Marathe, Rahul

    2017-05-01

    Miniaturized heat engines constitute a fascinating field of current research. Many theoretical and experimental studies are being conducted that involve colloidal particles in harmonic traps as well as bacterial baths acting like thermal baths. These systems are micron-sized and are subjected to large thermal fluctuations. Hence, for these systems average thermodynamic quantities, such as work done, heat exchanged, and efficiency, lose meaning unless otherwise supported by their full probability distributions. Earlier studies on microengines are concerned with applying Carnot or Stirling engine protocols to miniaturized systems, where system undergoes typical two isothermal and two adiabatic changes. Unlike these models we study a prototype system of two classical Ising spins driven by time-dependent, phase-different, external magnetic fields. These spins are simultaneously in contact with two heat reservoirs at different temperatures for the full duration of the driving protocol. Performance of the model as an engine or a refrigerator depends only on a single parameter, namely the phase between two external drivings. We study this system in terms of fluctuations in efficiency and coefficient of performance (COP). We find full distributions of these quantities numerically and study the tails of these distributions. We also study reliability of the engine. We find the fluctuations dominate mean values of efficiency and COP, and their probability distributions are broad with power law tails.

  2. Undulative induction electron accelerator for the waste and natural water purification systems

    CERN Document Server

    Kulish, Victor V; Gubanov, I V

    2001-01-01

    The project analysis of Undulative Induction Accelerator (EH - accelerator) for the waste and natural water purification systems is accomplished. It is shown that the use of the four-channel design of induction block and the standard set of auxiliary equipment (developed earlier for the Linear Induction Accelerators - LINACs) allow to construct commercially promising purification systems. A quality analysis of the accelerator is done and the optimal parameters are chosen taking into account the specific sphere of its usage.

  3. Dysregulated physiological stress systems and accelerated cellular aging.

    Science.gov (United States)

    Révész, Dóra; Verhoeven, Josine E; Milaneschi, Yuri; de Geus, Eco J C N; Wolkowitz, Owen M; Penninx, Brenda W J H

    2014-06-01

    Exposure to chronic stressors is associated with accelerated biological aging as indicated by reduced leukocyte telomere length (LTL). This impact could be because of chronic overactivation of the body's physiological stress systems. This study examined the associations between LTL and the immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system. LTL was assessed in 2936 adults from the Netherlands Study of Depression and Anxiety. Inflammation markers (interleukin-6, c-reactive protein, tumor necrosis factor-alpha), hypothalamic-pituitary-adrenal-axis indicators (salivary cortisol awakening curve [area under the curve indicators, with respect to the ground and increase], evening levels, 0.5 mg dexamethasone cortisol suppression ratio), and autonomic nervous system measures (heart rate, respiratory sinus arrhythmia, pre-ejection period) were determined. Linear regression analyses were performed and adjusted for sociodemographic, lifestyle and clinical factors. Shorter LTL was significantly associated with higher c-reactive protein, interleukin-6, area under the curve with respect to increase, and heart rate. A cumulative index score was calculated based on the number of highest tertiles of these 4 stress markers. LTL demonstrated a significant gradient within subjects ranging from having zero (5528 base pairs) to having 4 elevated stress markers (5371 base pairs, p for trend = 0.002), corresponding to a difference of 10 years of accelerated biological aging. Contrary to the expectations, shorter LTL was also associated with longer pre-ejection period, indicating lower sympathetic tone. This large-scale study showed that inflammation, high awakening cortisol response, and increased heart rate are associated with shorter LTL, especially when they are dysregulated cumulatively. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Development of Power System for Medium Energy Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyeok Jung; Cho, Y. S.; Jang, J. H.; Kim, Y. H.; Han, S. H.; Seol, K. T.; Hong, I. S.; Kim, H. S.; Song, Y. G

    2005-07-15

    The power supply system for 100MeV accelerator has been designed and one set of high voltage power supply was development. The requirements of the high voltage power supply are 100kV, 20A, < 20J. As a result of comparing various types of power supply, AC controller with SCR was selected and semiconductor opening switch was designed to limit the load arc energy. The Mod. anode power supply consisted of voltage dividing resistors and tetrode. Through the circuit analysis, the capacity of resistors and tetrode has been optimized. Two types of commercially available switching power supply were tested for klystron electromagnet, and it was determined that power supply with series connected module could meet the requirement. A full bridge converter was designed and developed for DTL quadrupole manget power supply. Those have been tested and now being operated. One set of high voltage power supply was developed and its components tested. The thyristor panel was tested up to 800A to validate the SCR firing. A switching test and arc test of the HVS tank were also carried out. The test results showed that the components well satisfied the requirements. The high voltage power supply will be used as a klystron power supply for 100MeV accelerator.

  5. Multi-source driven capillary plane radiation air conditioning system

    Science.gov (United States)

    Hu, Juanjuan; Qu, Mofeng; Wang, Huasheng; Ni, Shiyao

    2017-08-01

    A new absorption refrigeration system, which is driven by solar energy, biomass energy and geothermal energy simultaneously, was designed with capillaries as its radiation surface. Likewise, variations of water temperature in the capillaries with the change in both time and its flow rate were experimentally researched as well as how COP of the system varies with the surrounding temperature. The following conclusions have been obtained: Common refrigeration demand can be met by the system after its operation in 1 hour; with the increase in water flow rate in the capillaries, its temperature, which drops down after an increase, gets its peak value at the flow rate of 4.5-5.5 L/min; COP of the system decreases with the rise of surrounding temperature, thus it's better to keep it from direct sunlight. With the utilization of natural energy and the structure of capillaries, the system's advantages in simple structure, low cost, environment-friendly working process and nice performance lead to promising application prospects, especially in residence refrigeration in countryside.

  6. Accelerating and benchmarking operating system functions in a “soft” system

    Directory of Open Access Journals (Sweden)

    Péter Molnár

    2015-06-01

    Full Text Available The todays computing technology provokes serious debates whether the operating system functions are implemented in the best possible way. The suggestions range from accelerating only certain functions through providing complete real-time operating systems as coprocessors to using simultaneously hardware and software implemented threads in the operating system. The performance gain in such systems depends on many factors, so its quantification is not a simple task at all. In addition to the subtleties of operating systems, the hardware accelerators in modern processors may considerably affect the results of such measurements. The reconfigurable systems offer a platform, where even end users can carry out reliable and accurate measurements. The paper presents a hardware acceleration idea for speeding up a simple OS service, its verification setup and the measurement results.

  7. Dual linear accelerator system for use in sterilization of medical disposable supplies

    Science.gov (United States)

    Sadat, Theo

    1991-05-01

    Accelerators can be used for sterilization or decontamination (medical disposables, food, plastics, hospital waste, etc.). Most of these accelerators are located in an industrial environment and must have a high availability. A dual accelerator system (composed of two accelerators) offers optimal flexibility and reliability. The main advantage of this system is "all-in all-out" because it does not need a turnover of products. Such a dual system, composed of two 10 MeV 20 kW linear accelerators (instead of one 40 kW linac), has been chosen by a Swedish company (Mölnlycke).

  8. Dissipation, lag, and drift in driven fluctuating systems

    Science.gov (United States)

    Frezzato, Diego

    2017-12-01

    This work deals with thermostated fluctuating systems subjected to driven transformations of the internal energetics. The main focus is on generally multidimensional systems with continuous configurational degrees of freedom over which overdamped Markovian fluctuations take place (diffusive regime of the motion). Mutual bounds are established between the average energy dissipation, the deviation between nonequilibrium probability density and underlying equilibrium distribution due to the system's lag, and the statistical properties of the components of the directed flow induced by the transformation itself. The directed flow is here expressed in terms of time-dependent "drift velocity" associated with the probability current in a advection-like formulation of the nonstationary Fokker-Planck equation. Consideration of the drift makes that the bounds achieved here extend the inequality derived by Vaikuntanathan and Jarzynski [Europhys. Lett. 87, 60005 (2009), 10.1209/0295-5075/87/60005] involving only dissipation and lag. The key relations are then specified for the so-called stochastic pumps, i.e., systems that reach a periodic steady state in response of cyclic transformations and that are prototypes of nonautonomous dissipative converters of input energy into directed motion; a one-dimensional case model is adopted to illustrate the main features. Complementary results concerning bounds between the evolution rates of dissipation and lag, valid for both overdamped and underdamped dynamics, are also presented.

  9. Critical quasienergy states in driven many-body systems

    Science.gov (United States)

    Bastidas Valencia, Victor Manuel; Engelhardt, Georg; Perez-Fernandez, Pedro; Vogl, Malte; Brandes, Tobias

    2015-03-01

    A quantum phase transition (QPT) is characterized by non-analyticities of ground-state properties at the critical points. Recently it has been shown that quantum criticality emerges also in excited states of the system, which is referred to as an excited-state quantum phase transition (ESQPT). This kind of quantum criticality is intimately related to a level clustering at critical energies, which results in a logarithmic singularity in the density of states. Most of the previous studies on quantum criticality in excited states have been focused on time independent systems. Here we study spectral singularities that appear in periodically-driven many-body systems and show how the external control allows one to engineer geometrical features of the quasienergy landscape. In particular, we study singularities in the quasienergy spectrum of a fully-connected network consisting of two-level systems with time-dependent interactions. We discuss the characteristic signatures of these singularities in observables like the magnetization, which should be measurable with current technology. The authors gratefully acknowledge financial support by the DFG via grants BRA 1528/7, BRA 1528/8, SFB 910 (V.M.B., T.B.), the Spanish Ministerio de Ciencia e Innovacion (Grants No. FIS2011-28738-C02-01) and Junta de Andalucia (Grants No. FQM160).

  10. Archetype Model-Driven Development Framework for EHR Web System.

    Science.gov (United States)

    Kobayashi, Shinji; Kimura, Eizen; Ishihara, Ken

    2013-12-01

    This article describes the Web application framework for Electronic Health Records (EHRs) we have developed to reduce construction costs for EHR sytems. The openEHR project has developed clinical model driven architecture for future-proof interoperable EHR systems. This project provides the specifications to standardize clinical domain model implementations, upon which the ISO/CEN 13606 standards are based. The reference implementation has been formally described in Eiffel. Moreover C# and Java implementations have been developed as reference. While scripting languages had been more popular because of their higher efficiency and faster development in recent years, they had not been involved in the openEHR implementations. From 2007, we have used the Ruby language and Ruby on Rails (RoR) as an agile development platform to implement EHR systems, which is in conformity with the openEHR specifications. We implemented almost all of the specifications, the Archetype Definition Language parser, and RoR scaffold generator from archetype. Although some problems have emerged, most of them have been resolved. We have provided an agile EHR Web framework, which can build up Web systems from archetype models using RoR. The feasibility of the archetype model to provide semantic interoperability of EHRs has been demonstrated and we have verified that that it is suitable for the construction of EHR systems.

  11. Scheme for proton-driven plasma-wakefield acceleration of positively charged particles in a hollow plasma channel

    Directory of Open Access Journals (Sweden)

    Longqing Yi (易龙卿

    2013-07-01

    Full Text Available A new scheme for accelerating positively charged particles in a plasma-wakefield accelerator is proposed. If the proton drive beam propagates in a hollow plasma channel, and the beam radius is of order of the channel width, the space charge force of the driver causes charge separation at the channel wall, which helps to focus the positively charged witness bunch propagating along the beam axis. In the channel, the acceleration buckets for positively charged particles are much larger than in the blowout regime of the uniform plasma, and stable acceleration over long distances is possible. In addition, phasing of the witness with respect to the wave can be tuned by changing the radius of the channel to ensure the acceleration is optimal. Two-dimensional simulations suggest that, for proton drivers likely available in future, positively charged particles can be stably accelerated over 1 km with the average acceleration gradient of 1.3  GeV/m.

  12. Hybrid laser-plasma wakefield acceleration

    Science.gov (United States)

    Hidding, Bernhard; Heinemann, Thomas; Scherkl, Paul; Ullmann, Daniel; Beaton, Andrew

    2017-10-01

    Laser wakefield accelerators (LWFA) can produce electron bunches with characteristics which suggest they are highly suitable to be used as drivers for electron-beam driven plasma wakefield accelerators (PWFA). The presentation will report on recent experimental results and conceptual advanced which substantiate this idea. It looks as if hybrid LWFA-PWFA systems are highly promising systems to harness specific advantages of PWFA (no dephasing, long acceleration distances, wide potential for ionization injection schemes) realized these in truly compact systems.

  13. Optimum design and criticality safety of a beam-shaping assembly with an accelerator-driven subcritical neutron multiplier for boron neutron capture therapies.

    Science.gov (United States)

    Hiraga, F

    2015-12-01

    The beam-shaping assembly for boron neutron capture therapies with a compact accelerator-driven subcritical neutron multiplier was designed so that an epithermal neutron flux of 1.9×10(9) cm(-2) s(-1) at the treatment position was generated by 5 MeV protons in a beam current of 2 mA. Changes in the atomic density of (135)Xe in the nuclear fuel due to the operation of the beam-shaping assembly were estimated. The criticality safety of the beam-shaping assembly in terms of Xe poisoning is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Analysis of Intelligent Transportation Systems Using Model-Driven Simulations.

    Science.gov (United States)

    Fernández-Isabel, Alberto; Fuentes-Fernández, Rubén

    2015-06-15

    Intelligent Transportation Systems (ITSs) integrate information, sensor, control, and communication technologies to provide transport related services. Their users range from everyday commuters to policy makers and urban planners. Given the complexity of these systems and their environment, their study in real settings is frequently unfeasible. Simulations help to address this problem, but present their own issues: there can be unintended mistakes in the transition from models to code; their platforms frequently bias modeling; and it is difficult to compare works that use different models and tools. In order to overcome these problems, this paper proposes a framework for a model-driven development of these simulations. It is based on a specific modeling language that supports the integrated specification of the multiple facets of an ITS: people, their vehicles, and the external environment; and a network of sensors and actuators conveniently arranged and distributed that operates over them. The framework works with a model editor to generate specifications compliant with that language, and a code generator to produce code from them using platform specifications. There are also guidelines to help researchers in the application of this infrastructure. A case study on advanced management of traffic lights with cameras illustrates its use.

  15. Analysis of Intelligent Transportation Systems Using Model-Driven Simulations

    Directory of Open Access Journals (Sweden)

    Alberto Fernández-Isabel

    2015-06-01

    Full Text Available Intelligent Transportation Systems (ITSs integrate information, sensor, control, and communication technologies to provide transport related services. Their users range from everyday commuters to policy makers and urban planners. Given the complexity of these systems and their environment, their study in real settings is frequently unfeasible. Simulations help to address this problem, but present their own issues: there can be unintended mistakes in the transition from models to code; their platforms frequently bias modeling; and it is difficult to compare works that use different models and tools. In order to overcome these problems, this paper proposes a framework for a model-driven development of these simulations. It is based on a specific modeling language that supports the integrated specification of the multiple facets of an ITS: people, their vehicles, and the external environment; and a network of sensors and actuators conveniently arranged and distributed that operates over them. The framework works with a model editor to generate specifications compliant with that language, and a code generator to produce code from them using platform specifications. There are also guidelines to help researchers in the application of this infrastructure. A case study on advanced management of traffic lights with cameras illustrates its use.

  16. Analysis of Intelligent Transportation Systems Using Model-Driven Simulations

    Science.gov (United States)

    Fernández-Isabel, Alberto; Fuentes-Fernández, Rubén

    2015-01-01

    Intelligent Transportation Systems (ITSs) integrate information, sensor, control, and communication technologies to provide transport related services. Their users range from everyday commuters to policy makers and urban planners. Given the complexity of these systems and their environment, their study in real settings is frequently unfeasible. Simulations help to address this problem, but present their own issues: there can be unintended mistakes in the transition from models to code; their platforms frequently bias modeling; and it is difficult to compare works that use different models and tools. In order to overcome these problems, this paper proposes a framework for a model-driven development of these simulations. It is based on a specific modeling language that supports the integrated specification of the multiple facets of an ITS: people, their vehicles, and the external environment; and a network of sensors and actuators conveniently arranged and distributed that operates over them. The framework works with a model editor to generate specifications compliant with that language, and a code generator to produce code from them using platform specifications. There are also guidelines to help researchers in the application of this infrastructure. A case study on advanced management of traffic lights with cameras illustrates its use. PMID:26083232

  17. Accelerated Molecular Dynamics Simulations of Reactive Hydrocarbon Systems

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, Steven J.

    2014-02-25

    The research activities in this project consisted of four different sub-projects. Three different accelerated dynamics techniques (parallel replica dynamics, hyperdynamics, and temperature-accelerated dynamics) were applied to the modeling of pyrolysis of hydrocarbons. In addition, parallel replica dynamics was applied to modeling of polymerization.

  18. Accelerating next generation sequencing data analysis with system level optimizations.

    Science.gov (United States)

    Kathiresan, Nagarajan; Temanni, Ramzi; Almabrazi, Hakeem; Syed, Najeeb; Jithesh, Puthen V; Al-Ali, Rashid

    2017-08-22

    Next generation sequencing (NGS) data analysis is highly compute intensive. In-memory computing, vectorization, bulk data transfer, CPU frequency scaling are some of the hardware features in the modern computing architectures. To get the best execution time and utilize these hardware features, it is necessary to tune the system level parameters before running the application. We studied the GATK-HaplotypeCaller which is part of common NGS workflows, that consume more than 43% of the total execution time. Multiple GATK 3.x versions were benchmarked and the execution time of HaplotypeCaller was optimized by various system level parameters which included: (i) tuning the parallel garbage collection and kernel shared memory to simulate in-memory computing, (ii) architecture-specific tuning in the PairHMM library for vectorization, (iii) including Java 1.8 features through GATK source code compilation and building a runtime environment for parallel sorting and bulk data transfer (iv) the default 'on-demand' mode of CPU frequency is over-clocked by using 'performance-mode' to accelerate the Java multi-threads. As a result, the HaplotypeCaller execution time was reduced by 82.66% in GATK 3.3 and 42.61% in GATK 3.7. Overall, the execution time of NGS pipeline was reduced to 70.60% and 34.14% for GATK 3.3 and GATK 3.7 respectively.

  19. Thermopower Wave-Driven Hybrid Supercapacitor Charging System.

    Science.gov (United States)

    Shin, Dongjoon; Hwang, Hayoung; Yeo, Taehan; Seo, Byungseok; Choi, Wonjoon

    2016-11-16

    The development of new energy sources and harvesting methods has increased with the rapid development of multiscale wireless and portable systems. A thermopower wave (TW) is a potential portable energy source that exhibits a high power density. TWs generate electrical energy via the transport of charges inside micro- or nanostructured materials. This transport is induced by self-propagating combustion. Despite the high specific power of TWs, the generation of energy by TWs is transient, making a TW device a one-time use source, which is a critical limitation on the further advancement of this technology. Herein, we first report the development of a hybrid supercapacitor charging system driven by consecutive TWs to accumulate multiple amounts of energy generated by the repetitive combustion of the chemical fuel. In this study, hybrid layers composed of a supercapacitor (poly(vinyl alcohol)/MnO2/nickel) and solid fuel layer (nitrocellulose film) were fabricated as one integrated platform. Combustion was initiated by the ignition of the fuel layer, resulting in the production of electrical energy, attributed to the potential difference between two electrodes, and the transport of charges inside one of the electrodes. Electrical energy could simultaneously and directly charge the supercapacitor, and the discharged voltage could be significantly increased in comparison with the voltage level before the application of a TW. Furthermore, the application of multiple TWs in succession in the hybrid supercapacitor charging system successfully allowed for stack voltage amplification, which was synchronized to each TW. The results of this study could be used to understand the underlying phenomena for charging supercapacitors with the variation of thermal energy and to advance the application of TWs as more efficient, practical energy sources.

  20. Quasi-monoenergetic electron beams from a few-terawatt laser driven plasma acceleration using a nitrogen gas jet

    Science.gov (United States)

    Rao, B. S.; Moorti, A.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2017-06-01

    An experimental investigation on the laser plasma acceleration of electrons has been carried out using 3 TW, 45 fs duration titanium sapphire laser pulse interaction with a nitrogen gas jet at an intensity of 2 × 1018 W cm-2. We have observed the stable generation of a well collimated electron beam with divergence and pointing variation ˜10 mrad from nitrogen gas jet plasma at an optimum plasma density around 3 × 1019 cm-3. The energy spectrum of the electron beam was quasi-monoenergetic with an average peak energy and a charge around 25 MeV and 30 pC respectively. The results will be useful for better understanding and control of ionization injection and the laser wakefield acceleration (LWFA) of electrons in high-Z gases and also towards the development of practical LWFA for various applications including injectors for high energy accelerators.

  1. Evolution and development of the Oak Ridge 25URC tandem accelerator control system

    Science.gov (United States)

    Juras, R. C.; Ziegler, N. F.; Meigs, M. J.; McPherson, R. L.; Hoglund, D. E.; Biggerstaff, J. A.

    1988-05-01

    Since acceptance of the 25URC accelerator in 1982, we have continued to develop and improve both the accelerator control system and associated software. In this paper, we describe these improvements and also discuss how our experience with the present system would influence the architecture and design of future, similar systems.

  2. Evolution and development of the Oak Ridge 25URC tandem accelerator control system

    Energy Technology Data Exchange (ETDEWEB)

    Juras, R.C.; Ziegler, N.F.; Meigs, M.J.; McPherson, R.L.; Hoglund, D.E.; Biggerstaff, J.A.

    1988-05-20

    Since acceptance of the 25URC accelerator in 1982, we have continued to develop and improve both the accelerator control system and associated software. In this paper, we describe these improvements and also discuss how our experience with the present system would influence the architecture and design of future, similar systems.

  3. Evolution and development of the Oak Ridge 25URC tandem accelerator control system

    Energy Technology Data Exchange (ETDEWEB)

    Juras, R.C.; Ziegler, N.F.; Meigs, M.J.; McPherson, R.L.; Hoglund, D.E.; Biggerstaff, J.A.

    1987-01-01

    Since acceptance of the 25URC accelerator in 1982, we have continued to develop and improve both the accelerator control system and associated software. In this paper, we describe these improvements and also discuss how our experience with the present system would influence the architecture and design of future, similar systems.

  4. A Framework for a General Purpose Intelligent Control System for Particle Accelerators. Phase II Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Robert Westervelt; Dr. William Klein; Dr. Michael Kroupa; Eric Olsson; Rick Rothrock

    1999-06-28

    Vista Control Systems, Inc. has developed a portable system for intelligent accelerator control. The design is general in scope and is thus configurable to a wide range of accelerator facilities and control problems. The control system employs a multi-layer organization in which knowledge-based decision making is used to dynamically configure lower level optimization and control algorithms.

  5. Parametric Instability Rates in Periodically Driven Band Systems

    Science.gov (United States)

    Lellouch, S.; Bukov, M.; Demler, E.; Goldman, N.

    2017-04-01

    In this work, we analyze the dynamical properties of periodically driven band models. Focusing on the case of Bose-Einstein condensates, and using a mean-field approach to treat interparticle collisions, we identify the origin of dynamical instabilities arising from the interplay between the external drive and interactions. We present a widely applicable generic numerical method to extract instability rates and link parametric instabilities to uncontrolled energy absorption at short times. Based on the existence of parametric resonances, we then develop an analytical approach within Bogoliubov theory, which quantitatively captures the instability rates of the system and provides an intuitive picture of the relevant physical processes, including an understanding of how transverse modes affect the formation of parametric instabilities. Importantly, our calculations demonstrate an agreement between the instability rates determined from numerical simulations and those predicted by theory. To determine the validity regime of the mean-field analysis, we compare the latter to the weakly coupled conserving approximation. The tools developed and the results obtained in this work are directly relevant to present-day ultracold-atom experiments based on shaken optical lattices and are expected to provide an insightful guidance in the quest for Floquet engineering.

  6. Cosine edge modes in a periodically driven quantum system

    Science.gov (United States)

    Satija, Indubala I.; Zhao, Erhai

    2016-12-01

    Time-periodic (Floquet) topological phases of matter exhibit bulk-edge relationships that are more complex than static topological insulators and superconductors. Finding the edge modes unique to driven systems usually requires numerics. Here we present a minimal two-band model of Floquet topological insulators and semimetals in two dimensions where all the bulk and edge properties can be obtained analytically. It is based on the extended Harper model of quantum Hall effect at flux one-half. We show that periodical driving gives rise to a series of phases characterized by a pair of integers. The model has a most striking feature: the spectrum of the edge modes is always given by a single cosine function, ω (ky) ∝cosky where ky is the wave number along the edge, as if it is freely dispersing and completely decoupled from the bulk. The cosine mode is robust against the change in driving parameters. It also persists in the semimetallic phases with Dirac points.

  7. Accelerator applications in energy and security

    CERN Document Server

    Chou, Weiren

    2015-01-01

    As accelerator science and technology progressed over the past several decades, the accelerators themselves have undergone major improvements in multiple performance factors: beam energy, beam power, and beam brightness. As a consequence, accelerators have found applications in a wide range of fields in our life and in our society. The current volume is dedicated to applications in energy and security, two of the most important and urgent topics in today's world. This volume makes an effort to provide a review as complete and up to date as possible of this broad and challenging subject. It contains overviews on each of the two topics and a series of articles for in-depth discussions including heavy ion accelerator driven inertial fusion, linear accelerator-based ADS systems, circular accelerator-based ADS systems, accelerator-reactor interface, accelerators for fusion material testing, cargo inspection, proton radiography, compact neutron generators and detectors. It also has a review article on accelerator ...

  8. System and safety studies of accelerator driven systems for transmutation. Annual report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Arzhanov, Vasily; Bergloef, Calle; Fokau, Andrei; Jolkkonen, Mikael; Runevall, Odd; Sandberg, Nils; Tesinsky, Milan; Wallenius, Janne; Youpeng Zhang (Div. of Reactor Physics, Royal Institute of Technology, Stockholm (Sweden))

    2009-07-15

    Within this project, research on design and safety of subcritical reactors for recycling of minor actinides is performed. During 2008, the reactor physics division at KTH has made a design study of a source efficient ADS with nitride fuel, based on the EFIT design made within the EUROTRANS project. Transient analysis for EFIT-400 ADS with cercer and cermet fuels was made with SAS4A, taking into account flow reversal phenomena. Using Pulsed Neutron Source techniques, reference reactivity values for detectors in the sub-critical YALINA booster facility were obtained and it was observed that the results carry strong spatial effects. It was shown that the beam trip technique can be used to obtain the reactivity at beam trips and the values can be used for calibration of a current-to-flux reactivity indicator. Multi-scale modelling of helium desorption from molybdenum was performed, with the final aim to predict the in-pile behaviour of Mo based CERMET fuel. Good agreement with experimental data was obtained, except at the highest temperatures

  9. Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems

    Directory of Open Access Journals (Sweden)

    Sharma S

    2007-01-01

    Full Text Available Stereotactic radiosurgery (SRS is a special radiotherapy technique used to irradiate intracranial lesions by 3-D arrangements of narrow photon beams eliminating the needs of invasive surgery. Three different tertiary collimators, namely BrainLab and Radionics circular cones and BrainLab micro multileaf collimator (mMLC, are used for linear accelerator-based SRS systems (X-Knife. Output factor (St, tissue maximum ratio (TMR and off axis ratio (OAR of these three SRS systems were measured using CC01 (Scanditronix/ Welhofer and Pinpoint (PTW cylindrical and Markus plane parallel ionization chambers as well as TLD and radiochromic film. Measurement results of CC01 and Pinpoint chambers were very close to each other which indicate that further reduction in volume and physical dimensions of cylindrical ionization chamber is not necessary for SRS/SRT dosimetry. Output factors of BrainLab and Radionics SRS cones were very close to each other while output factors of equivalent diameter mMLC field were different from SRS circular cones. TMR of the three SRS systems compared were very close to one another. OAR of Radionics cone and BrainLab mMLC were very close to each other, within 2%. However, OARs of BrainLab cone were found comparable to OARs of Radionics cone and BrainLab mMLC within maximum variation of 4%. In addition, user-measured similar data of other three mMLC X-Knives were compared with the mMLC X-Knife data measured in this work and found comparable. The concept of switching over to mMLC-based SRS/SRT is thus validated from dosimetric characteristics as well.

  10. FPGA Mezzanine Cards for CERN’s Accelerator Control System

    CERN Document Server

    Alvarez, P R; Lewis, J; Serrano, J; Wlostowski, T

    2009-01-01

    Field Programmable Gate Arrays (FPGAs) have become a key player in modern real time control systems. They offer determinism, simple design, high performance and versatility. A typical hardware architecture consists of an FPGA interfaced with a control bus and a variable number of digital IOs, ADCs and DACs depending on the application. Until recently the low-cost hardware paradigm has been using mezzanines containing a front end interface plus custom logic (typically an FPGA) and a local bus that interfaces the mezzanine to a carrier. As FPGAs grow in size and shrink in price, hardware reuse, testability and bus access speed could be improved if the user logic is moved to the carrier. The new FPGA Mezzanine Card (FMC) Vita 57 standard is a good example of this new paradigm. In this paper we present a standard kit of FPGA carriers and IO mezzanines for accelerator control. Carriers form factors will be VME, PCI and PCIe. The carriers will feature White Rabbit support for accurate synchronization of distributed...

  11. Robust control of a class of chaotic and hyperchaotic driven systems

    Indian Academy of Sciences (India)

    This paper proposes new conditions which are sufficient for robust control of a class of chaotic and hyperchaotic driven systems. The drive–driven systems are characterized by non-identical uncertain complex dynamics where complexities are mainly introduced by the switching nature of their vector fields.

  12. A Timing-Driven Partitioning System for Multiple FPGAs

    Directory of Open Access Journals (Sweden)

    Kalapi Roy

    1996-01-01

    Full Text Available Field-programmable systems with multiple FPGAs on a PCB or an MCM are being used by system designers when a single FPGA is not sufficient. We address the problem of partitioning a large technology mapped FPGA circuit onto multiple FPGA devices of a specific target technology. The physical characteristics of the multiple FPGA system (MFS pose additional constraints to the circuit partitioning algorithms: the capacity of each FPGA, the timing constraints, the number of I/Os per FPGA, and the pre-designed interconnection patterns of each FPGA and the package. Existing partitioning techniques which minimize just the cut sizes of partitions fail to satisfy the above challenges. We therefore present a timing driven N-way partitioning algorithm based on simulated annealing for technology-mapped FPGA circuits. The signal path delays are estimated during partitioning using a timing model specific to a multiple FPGA architecture. The model combines all possible delay factors in a system with multiple FPGA chips of a target technology. Furthermore, we have incorporated a new dynamic net-weighting scheme to minimize the number of pin-outs for each chip. Finally, we have developed a graph-based global router for pin assignment which can handle the pre-routed connections of our MFS structure. In order to reduce the time spent in the simulated annealing phase of the partitioner, clusters of circuit components are identified by a new linear-time bottom-up clustering algorithm. The annealing-based N-way partitioner executes four times faster using the clusters as opposed to a flat netlist with improved partitioning results. For several industrial circuits, our approach outperforms the recursive min-cut bi-partitioning algorithm by 35% in terms of nets cut. Our approach also outperforms an industrial FPGA partitioner by 73% on average in terms of unroutable nets. Using the performance optimization capabilities in our approach we have successfully partitioned the

  13. Propagation speed, linear stability, and ion acceleration in radially imploding Hall-driven electron-magnetohydrodynamic shocks

    Science.gov (United States)

    Richardson, A. S.; Swanekamp, S. B.; Jackson, S. L.; Mosher, D.; Ottinger, P. F.

    2018-01-01

    Plasma density gradients are known to drive magnetic shocks in electron-magnetohydrodynamics. Previous slab modeling has been extended to cylindrical modeling of radially imploding shocks. The main new effect of the cylindrical geometry is found to be a radial dependence in the speed of shock propagation. This is shown here analytically and in numerical simulations. Ion acceleration by the magnetic shock is shown to possibly become substantial, especially in the peaked structures that develop in the shock because of electron inertia.

  14. Gamma-ray generation from laser-driven electron resonant acceleration: In the non-QED and the QED regimes

    Science.gov (United States)

    Qiao, B.; Chang, H. X.; Xie, Y.; Xu, Z.; He, X. T.

    2017-12-01

    Electron acceleration and γ-ray emission by circularly polarized laser pulses interacting with near-critical-density plasmas are systematically investigated for both the non-quantum-electrodynamic (non-QED) and QED regimes. In the non-QED regime, since electron density in the plasma channel is small and the self-generated electromagnetic fields are weak, only a few electrons can achieve the resonant acceleration, leading to weak γ-ray emission. However, when it comes to the QED regime, the radiation recoil force significantly affects the electron dynamics, which helps in not only the trapping of electrons, but also the relaxing of the condition for electrons to hit the resonance with laser fields, resulting in the formation of an ultradense helical electron bunch under resonant acceleration in the plasma channel. Therefore, an intense γ-ray pulse with unprecedented flux can be generated. Theoretical analysis and three-dimensional particle-in-cell simulations are carried out to compare the dynamics in two different regimes.

  15. Second-Order Multiagent Systems with Event-Driven Consensus Control

    Directory of Open Access Journals (Sweden)

    Jiangping Hu

    2013-01-01

    Full Text Available Event-driven control scheduling strategies for multiagent systems play a key role in future use of embedded microprocessors of limited resources that gather information and actuate the agent control updates. In this paper, a distributed event-driven consensus problem is considered for a multi-agent system with second-order dynamics. Firstly, two kinds of event-driven control laws are, respectively, designed for both leaderless and leader-follower systems. Then, the input-to-state stability of the closed-loop multi-agent system with the proposed event-driven consensus control is analyzed and the bound of the inter-event times is ensured. Finally, some numerical examples are presented to validate the proposed event-driven consensus control.

  16. Using a batch processor to create an interactive menu-driven operating system

    Energy Technology Data Exchange (ETDEWEB)

    Melvin, W.R.

    1982-02-01

    Many stand-alone mini/microcomputing systems have available batch-processing software. With a bit of creative misuse, this batch-processing software can be turned into an interactive menu-driven operating system.

  17. Radiation protection system installation for the accelerator production of tritium/low energy demonstration accelerator project (APT/LEDA)

    CERN Document Server

    Wilmarth, J E; Tomei, T L

    2000-01-01

    The APT/LEDA personnel radiation protection system installation was accomplished using a flexible, modular proven system which satisfied regulatory orders, project design criteria, operational modes, and facility requirements. The goal of providing exclusion and safe access of personnel to areas where prompt radiation in the LEDA facility is produced was achieved with the installation of a DOE-approved Personnel Access Control System (PACS). To satisfy the facility configuration design, the PACS, a major component of the overall radiation safety system, conveniently provided five independent areas of personnel access control. Because of its flexibility and adaptability the Los-Alamos Neutron- Science-Center-(LANSCE)-designed Radiation Security System (RSS) was efficiently configured to provide the desired operational modes and satisfy the APT/LEDA project design criteria. The Backbone Beam Enable (BBE) system based on the LANSCE RSS provided the accelerator beam control functions with redundant, hardwired, ta...

  18. RADIATION PROTECTION SYSTEM INSTALLATION FOR THE ACCELERATOR PRODUCTION OF TRITIUM/LOW ENERGY DEMONSTRATION ACCELERATOR PROJECT (APT/LEDA)

    Energy Technology Data Exchange (ETDEWEB)

    J. WILMARTH; M. SMITH; T. TOMEI

    1999-07-01

    The APT/LEDA personnel radiation protection system installation was accomplished using a flexible, modular proven system which satisfied regulatory orders, project design criteria, operational modes, and facility requirements. The goal of providing exclusion and safe access of personnel to areas where prompt radiation in the LEDA facility is produced was achieved with the installation of a DOE-approved Personnel Access Control System (PACS). To satisfy the facility configuration design, the PACS, a major component of the overall radiation safety system, conveniently provided five independent areas of personnel access control. Because of its flexibility and adaptability the Los Alamos Neutron Science Center (LANSCE) designed Radiation Security System (RSS) was efficiently configured to provide the desired operational modes and satisfy the APT/LEDA project design criteria. The Backbone Beam Enable (BBE) system based on the LANSCE RSS provided the accelerator beam control functions with redundant, hardwired, tamper-resistant hardware. The installation was accomplished using modular components.

  19. Development of a RF-driven ion source for the ITER NBI system

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)], E-mail: albrecht.staebler@ipp.mpg.de; Fantz, U.; Franzen, P.; Berger, M.; Christ-Koch, S.; Falter, H.D.; Froeschle, M.; Gutser, R.; Heinemann, B.; Holtum, D.; Kraus, W.; Martens, C.; McNeely, P.; Nocentini, R.; Obermayer, S.; Riedl, R.; Speth, E.; Wuenderlich, D. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)

    2009-06-15

    Extensive R and D work on RF-driven negative hydrogen ion sources carried out at IPP Garching led to the decision of ITER to select this type of source as the new reference source for the ITER NBI system. The principle suitability of the RF source has been demonstrated in a small scale, short pulse length experiment: accelerated current densities, co-extracted electron currents at a source operation pressure, all well inside the range of the ITER requirements have been achieved simultaneously. In subsequent experiments, pulse lengths up to 1 h and the possibility of modularly extending the source to ITER source dimensions were demonstrated. The results achieved at the various IPP test beds, the lessons learnt during optimising the source for negative ion production and extraction as well as the problems still to be solved are summarized. As the next step in support of the NBI development for ITER, IPP plans to build a new test facility for beam extraction from a source of half the size for ITER.

  20. Compact Superconducting Radio-frequency Accelerators and Innovative RF Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, Robert [Fermilab; Chattopadhyay, Swaapan [Northern Illinois U.; Milton, Stephen [Colorado State U.

    2015-04-10

    We will present several new technical and design breakthroughs that enable the creation of a new class of compact linear electron accelerators for industrial purposes. Use of Superconducting Radio-Frequency (SRF) cavities allow accelerators less than 1.5 M in length to create electron beams beyond 10 MeV and with average beam powers measured in 10’s of KW. These machines can have the capability to vary the output energy dynamically to produce brehmstrahlung x-rays of varying spectral coverage for applications such as rapid scanning of moving cargo for security purposes. Such compact accelerators will also be cost effective for many existing and new industrial applications. Examples include radiation crosslinking of plastics and rubbers, creation of pure materials with surface properties radically altered from the bulk, modification of bulk or surface optical properties of materials, sterilization of medical instruments animal solid or liquid waste, and destruction of organic compounds in industrial waste water effluents. Small enough to be located on a mobile platform, such accelerators will enable new remediation methods for chemical and biological spills and/or in-situ crosslinking of materials. We will describe one current design under development at Fermilab including plans for prototype and value-engineering to reduce costs. We will also describe development of new nano-structured field-emitter arrays as sources of electrons, new methods for fabricating and cooling superconducting RF cavities, and a new novel RF power source based on magnetrons with full phase and amplitude control.

  1. The Effect of Novel Binary Accelerator System on Properties of Vulcanized Natural Rubber

    Directory of Open Access Journals (Sweden)

    Moez Kamoun

    2009-01-01

    Full Text Available The mechanical properties, curing characteristics, and swelling behaviour of vulcanized natural rubber with a novel binary accelerator system are investigated. Results indicate that the mechanical properties were improved. Crosslinking density of vulcanized natural rubber was measured by equilibrium swelling method. As a result, the new binary accelerator was found to be able to improve both cure rate and crosslinking density. Using the numerical analysis of test interaction between binary accelerator and operational modelling of vulcanization-factors experiments, it can be concluded that the interaction (Cystine, N-cyclohexyl-2-benzothiazyl sulfenamide was significant and the optimum value of binary accelerator was suggested, respectively, at levels 0 and +1.

  2. Design and Fabrication of the 'ITER-like' Singap D{sup -} Acceleration System

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, P.; Esch, H.P.L. de; Hemsworth, R.S.; Svensson, L. [Association Euratom-CEA, Centre d' Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2004-07-01

    The SINGAP acceleration concept is an alternative to the ITER neutral beam injection (NBI). A prototype SINGAP D{sup -} system has been operating in the Cadarache 1 MeV, 100 mA test bed for several years but with this equipment it is not possible to produce the quasi parallel beams of 5 mrad overall divergence and the current density required for ITER. A new accelerator as well as 2 negative ion sources have been designed. First beams up to 850 keV have been obtained after only 4 weeks of commissioning. The accelerator consists of a pre-accelerator stage and a post-accelerator. The author describes the accelerator, the 2 ion sources and reports the first results obtained. (A.C.)

  3. Simulation and characterization of the RF system and global stability analysis at the REGAE linear electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Mayet, Frank

    2012-12-15

    LAOLA (LAboratory for Laser- and beam-driven plasma Acceleration), is a collaboration between groups from DESY and the University of Hamburg. Its mission is to complement basic research in the relatively new field of plasma wakefield acceleration (PWA) by an explicit combination with DESY's conventional, modern accelerators. The linear electron accelerator REGAE is designed to produce sub 10 fs low charge electron bunches with ultra-low emittance at a repetition rate of 50 Hz. The planned experiments include femtosecond electron diffraction (R.J. Dwayne Miller), as well as the probing of laser induced plasma wakefields with well characterized bunches (LAOLA). They all require high bunch time of flight stability down to 10 fs. The REGAE machine consists of two RF cavities, both fed by a single klystron. While the first one - the gun cavity - is used for acceleration of the electrons, the second one - the buncher cavity - can be used to reduce the electron bunch length. This scheme only works for a specific RF phase relation between the two cavities. This thesis is split into two parts. In the first one the implications of the unique two cavity design on day-to-day machine operation are analyzed. To this end an analytical model of the RF system is developed, which is necessary for understanding how to individually adjust the cavity phases. In the second part the influence of the setup on time of flight stability is discussed with an emphasis on phase jitter compensation. RF phase stability measurements reveal that the current machine setup allows for a time of flight stability down to 50 fs right after the gun.

  4. A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

    Science.gov (United States)

    Persaud, A.; Ji, Q.; Feinberg, E.; Seidl, P. A.; Waldron, W. L.; Schenkel, T.; Lal, A.; Vinayakumar, K. B.; Ardanuc, S.; Hammer, D. A.

    2017-06-01

    A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

  5. Multi-GeV electron beam and high brightness betatron x-ray generation in recent Texas Petawatt laser-driven plasma accelerator experiments

    Science.gov (United States)

    Wang, Xiaoming; Zgadzaj, Rafal; Fazel, Neil; Li, Zhengyan; Zhang, Xi; Henderson, Watson; Chang, Yen-Yu; Korzekwa, Rick; Tsai, H.-E.; Quevedo, Hernan; Dyer, Gilliss; Gaul, Erhard; Martinez, Mikael; Bernstein, Aaron; Spinks, Michael; Gordan, Joseph; Donovan, Michael; Khudik, Vladimir; Shvets, Gennady; Ditmire, Todd; Downer, Michael

    2014-10-01

    Compact laser-plasma accelerators (LPAs) driven by petawatt (PW) lasers have produced highly collimated, quasi-monoenergetic multi-GeV electron bunches with ~100 pC charge, which are promising sources of ultrafast x-rays. Here we report three recent advances in PW-LPA performance brought about by optimizing the focal volume of the Texas PW laser with a deformable mirror. First, we accelerated electrons up to 3 GeV with hundreds of pC over 1 GeV and 1 GeV, 10% >2 GeV). Third, by introducing a double-peaked laser focus, creating a ``double bubble'' that subsequently merged, we significantly increased electron charge (0.5 nC) above 1 GeV, while producing brighter (1022photon/mm2/rad/0.1%), harder (up to 30 keV) betatron x-rays, characterized by a multi-metal filter pack and phase-contrast imaging. We observe evidence of dimuon production by irradiating a high-Z target with this high-charge, GeV electron beam.

  6. Anomalous edge states and the bulk-edge correspondence for periodically-driven two dimensional systems

    DEFF Research Database (Denmark)

    Rudner, Mark Spencer; Lindner, Netanel; Berg, Erez

    2013-01-01

    revealed phenomena that cannot be characterized by analogy to the topological classification framework for static systems. In particular, in driven systems in two dimensions (2D), robust chiral edge states can appear even though the Chern numbers of all the bulk Floquet bands are zero. Here, we elucidate...... the crucial distinctions between static and driven 2D systems, and construct a new topological invariant that yields the correct edge-state structure in the driven case. We provide formulations in both the time and frequency domains, which afford additional insight into the origins of the “anomalous” spectra...... that arise in driven systems. Possibilities for realizing these phenomena in solid-state and cold-atomic systems are discussed....

  7. Developing the Systems Engineering Experience Accelerator (SEEA) Prototype and Roadmap

    Science.gov (United States)

    2013-12-31

    novice learner actions and thinking to that of expert SMEs. However, while this comparison could not be made in this implementation, it certainly...correcting errors and smoothing the learner and teacher activities. 2.3.2.1 User Interface and Status Visibility The User Interface was revised in...problem-solving ability, we must assess students’ ability to do each of these steps. The EA seeks to accelerate the learning of novice SE’s and advance

  8. Data-Driven Synthesis for Investigating Food Systems Resilience to Climate Change

    Science.gov (United States)

    Magliocca, N. R.; Hart, D.; Hondula, K. L.; Munoz, I.; Shelley, M.; Smorul, M.

    2014-12-01

    The production, supply, and distribution of our food involves a complex set of interactions between farmers, rural communities, governments, and global commodity markets that link important issues such as environmental quality, agricultural science and technology, health and nutrition, rural livelihoods, and social institutions and equality - all of which will be affected by climate change. The production of actionable science is thus urgently needed to inform and prepare the public for the consequences of climate change for local and global food systems. Access to data that spans multiple sectors/domains and spatial and temporal scales is key to beginning to tackle such complex issues. As part of the White House's Climate Data Initiative, the USDA and the National Socio-Environmental Synthesis Center (SESYNC) are launching a new collaboration to catalyze data-driven research to enhance food systems resilience to climate change. To support this collaboration, SESYNC is developing a new "Data to Motivate Synthesis" program designed to engage early career scholars in a highly interactive and dynamic process of real-time data discovery, analysis, and visualization to catalyze new research questions and analyses that would not have otherwise been possible and/or apparent. This program will be supported by an integrated, spatially-enabled cyberinfrastructure that enables the management, intersection, and analysis of large heterogeneous datasets relevant to food systems resilience to climate change. Our approach is to create a series of geospatial abstraction data structures and visualization services that can be used to accelerate analysis and visualization across various socio-economic and environmental datasets (e.g., reconcile census data with remote sensing raster datasets). We describe the application of this approach with a pilot workshop of socio-environmental scholars that will lay the groundwork for the larger SESYNC-USDA collaboration. We discuss the

  9. Present Trends In The Configurations And Applications Of Electrostatic Accelerator Systems

    Science.gov (United States)

    Norton, Gregory A.; Klody, George M.

    2011-06-01

    Despite the worldwide economic meltdown during the past two years and preceding any stimulus program projects, the market for electrostatic accelerators has increased on three fronts: new applications developed in an expanding range of fields; technical enhancements that increase the range, precision, and sensitivity of existing systems; and new accelerator projects in a growing number of developing countries. From the single application of basic nuclear structure research from the 1930's into the 1970's, the continued expansion of new applications and the technical improvements in electrostatic accelerators have dramatically affected the configurations and capabilities of accelerator systems to meet new requirements. This paper describes examples of recent developments in cosmology, exotic materials, high resolution RBS, compact AMS, dust acceleration, ion implantation, etc.

  10. A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

    CERN Document Server

    Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

    2005-01-01

    American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.

  11. Seabed resident event driven profiling system (SREP). Concept, design and tests

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.A.M.Q.; Afzulpurkar, S.; Maurya, P.K.; Fernandes, L.; Madhan, R.; Desa, E.S.; Dabolkar, N.A.; Navelkar, G.S.; Naik, L.; Shetye, V.G.; Shetty, N.B.; Prabhudesai, S.P.; Nagvekar, S.; Vimalakumari, D.

    The seabed resident event driven profiling system (SREP) described here offers a novel, optimized approach to profiling in coastal waters from seabed to sea surface during the rough seas encountered in the southwest monsoon season (June...

  12. Methods and system for controlled laser-driven explosive bonding

    Science.gov (United States)

    Rubenchik, Alexander M.; Farmer, Joseph C.; Hackel, Lloyd; Rankin, Jon

    2015-11-19

    A technique for bonding two dissimilar materials includes positioning a second material over a first material at an oblique angle and applying a tamping layer over the second martial. A laser beam is directed at the second material that generates a plasma at the location of impact on the second material. The plasma generates pressure that accelerates a portion of the second material to a very high velocity and towards the first material. The second material impacts the first material causing bonding of the two materials.

  13. Stabilization of breathers in a parametrically driven sine-Gordon system with loss

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Kivshar, Yu. S.; Samuelsen, Mogens Rugholm

    1991-01-01

    We demonstrate that in a parametrically driven sine-Gordon system with loss, a breather, if driven, can be maintained in a steady state at half the external frequency. In the small-amplitude limit the system is described by the effective perturbed nonlinear Schrödinger equation. For an arbitrary ...... breather amplitude the threshold field is determined by a perturbation method and compared with direct numerical simulations. Excellent agreement is found....

  14. Compton MeV Gamma-ray Source on Texas Petawatt Laser-Driven GeV Electron Accelerator

    Science.gov (United States)

    Shaw, Joseph M.; Tsai, Hai-En; Zgadzaj, Rafal; Wang, Xiaoming; Chang, Vincent; Fazel, Neil; Henderson, Watson; Downer, M. C.; Texas Petawatt Laser Team

    2015-11-01

    Compton Backscatter (CBS) from laser wakefield accelerated (LWFA) electron bunches is a promising compact, femtosecond (fs) source of tunable high-energy photons. CBS x-rays have been produced from LWFAs using two methods: (1) retro-reflection of the LWFA drive pulse via an in-line plasma mirror (PM); (2) scattering of a counter-propagating secondary pulse split from the drive pulse. Previously MeV photons were only demonstrated by the latter method, but the former method is self-aligning. Here, using the Texas Petawatt (TPW) laser and a self-aligned near-retro-reflecting PM, we generate bright CBS γ-rays with central energies higher than 10 MeV. The 100 μm focus of TPW delivers 100 J in 100 fs pulses, with intensity 6x1018 W/cm2 (a0 =1.5), to the entrance of a 6-cm long Helium gas cell. A thin, plastic PM immediately following the gas cell exit retro-reflects the LWFA driving pulse into the oncoming 0.5 - 2 GeV electron beam to produce a directional beam of γ-rays without significant bremsstrahlung background. A Pb-filter pack on a thick, pixelated, CsI(Tl) scintillator is used to estimate the spectrum via differential transmission and to observe the beam profile. Recorded beam profiles indicate a low divergence. Department of Physics, The University of Texas at Austin

  15. The influence of tertiary amine accelerators on the curing behaviors of epoxy/anhydride systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tao; Zhang, Chongfeng; Zhang, Junying, E-mail: zjybuct@gmail.com; Cheng, Jue

    2014-02-10

    Highlights: • The influences of two types of accelerators (BDMA and DMP-30) on curing reaction of DGEBF/MeHHPA systems were studied comparatively. • The activation energy and kinetic parameters of DGEBF/MeHHPA systems with accelerator content of 0.2 phr and 0.5 phr were calculated, respectively. • The dependence of autocatalytic and non-autocatalytic curing reaction on the loading of accelerators was discussed. • The non-catalytic curing reaction dominated absolutely in the curing process of DGEBF/MeHHPA systems when the accelerator contents were 0.2 phr. - Abstract: Accelerators have significant effects on the curing behaviors of epoxy/anhydride (diglycidyl ether of bisphenol-F/methylhexahydrophthalic anhydride, DGEBF/MeHHPA) systems. Non-isothermal DSC was used to investigate the influence of dimethyl benzylamine (BDMA, 0.2 phr/0.5 phr) and Tris-(dimethyl aminomethyl) phenol (DMP-30, 0.2 phr/0.5 phr) on the curing behaviors of DGEBF/MeHHPA systems, respectively. When the amount of accelerators was kept constant, the activation energy calculated by Kissinger method changed slightly in the presence of either BDMA or DMP-30. And, with increasing the accelerator content from 0.2 phr to 0.5 phr, the value of activation energy decreased from 115 kJ/mol to 85 kJ/mol. Furthermore, the calculation results of Málek method identified that all systems in this study fitted Sesták–Berggren (SB) model and the corresponding model parameters, m and n, were obtained. It was found that the contribution of autocatalytic reaction with low accelerator content (0.2 phr) was far less than that with high accelerator content (0.5 phr)

  16. Intense Flows in Librationally Driven Non-Axisymmetric Systems

    Science.gov (United States)

    Grannan, A. M.; Le Bars, M.; Cebron, D.; Aurnou, J. M.

    2013-12-01

    We present laboratory experimental results that demonstrate that librational forcing can drive intense motions of interior, low viscosity fluid layers. Longitudinal libration refers to small periodic changes in a satellite's mean rotation rate as it orbits a primary body. These libration studies are conducted using ellipsoidal acrylic containers filled with water. Particle image velocimetry (PIV) methods are used to measure the 2D velocity field in the equatorial plane over hundreds and thousands of libration cycles. In doing so we determine the coupled modes of the triadic resonance responsible for the instability that produces both intermittent and persistent turbulent motions in the bulk fluid. Additionally, we measure the amplitude and the growth rate for the instability and compare it with previous studies [1][2]. Excitation of global turbulence by librational forcing provides a mechanism for transferring rotational energy into fluid turbulence and thus may play an important role in the thermal evolution, interior dynamics, and magneto-hydrodynamics of librating bodies. [1] Cébron, D., M. Le Bars, J. Noir, J.M. Aurnou. (2012). Libration driven elliptical instability. Physics of Fluids 24, 061703. [2] Noir J., D. Cébron, M. Le Bars, A. Sauret, J.M. Aurnou (2012). Experimental study of libration-driven flows in non-axisymmetric containers, Physics of the Earth and Planetary Interiors 204-205, 1-10.

  17. Event-Driven Contrastive Divergence for Spiking Neuromorphic Systems

    Directory of Open Access Journals (Sweden)

    Emre eNeftci

    2014-01-01

    Full Text Available Restricted Boltzmann Machines (RBMs and Deep Belief Networks have been demonstrated to perform efficiently in variety of applications, such as dimensionality reduction, feature learning, and classification. Their implementation on neuromorphic hardware platforms emulating large-scale networks of spiking neurons can have significant advantages from the perspectives of scalability, power dissipation and real-time interfacing with the environment. However the traditional RBM architecture and the commonly used training algorithm known as Contrastive Divergence (CD are based on discrete updates and exact arithmetics which do not directly map onto a dynamical neural substrate. Here, we present an event-driven variation of CD to train a RBM constructed with Integrate & Fire (I&F neurons, that is constrained by the limitations of existing and near future neuromorphic hardware platforms. Our strategy is based on neural sampling, which allows us to synthesize a spiking neural network that samples from a target Boltzmann distribution. The reverberating activity of the network replaces the discrete steps of the CD algorithm, while Spike Time Dependent Plasticity (STDP carries out the weight updates in an online, asynchronous fashion.We demonstrate our approach by training an RBM composed of leaky I&F neurons with STDP synapses to learn a generative model of the MNIST hand-written digit dataset, and by testing it in recognition, generation and cue integration tasks. Our results contribute to a machine learning-driven approach for synthesizing networks of spiking neurons capable of carrying out practical, high-level functionality.

  18. Design concept of radiation control system for the high intensity proton accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori; Harada, Yasunori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics. (author)

  19. Advanced Klystrons for High Efficiency Accelerator Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Read, Michael; Ives, Robert Lawrence

    2014-03-26

    This program explored tailoring of RF pulses used to drive accelerator cavities. Simulations indicated that properly shaping the pulse risetime to match accelerator cavity characteristics reduced reflected power and increased total efficiency. Tailoring the pulse requires a high power, gridded, klystron to shape the risetime while also controlling the beam current. The Phase I program generated a preliminary design of a gridded electron gun for a klystron producing 5-10 MW of RF power. This required design of a segmented cathode using Controlled Porosity Reservoir cathodes to limit power deposition on the grid. The program was successful in computationally designing a gun producing a high quality electron beam with grid control. Additional analysis of pulse tailoring indicated that technique would only be useful for cavity drive pulses that were less than approximately 2-3 times the risetime. Otherwise, the efficiency gained during the risetime of the pulse became insignificant when considering the efficiency over the entire pulse. Consequently, it was determined that a Phase II program would not provide sufficient return to justify the cost. Never the less, other applications for a high power gridded gun are currently being pursued. This klystron, for example, would facilitate development inverse Comptom x-ray sources by providing a high repetition rate (10 -100 kHz) RF source.

  20. Rf System For The Industrial Linear Electron Accelerator At Kaeri (daejeon, Korea)

    CERN Document Server

    Arbuzov, V S; Evtushenko, Yu A; Gorniker, E I; Kenjebulatov, E K; Kondakov, A A; Krutikhin, S A; Kurkin, G Ya; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A R; Shteinke, A M; Tribendis, A G

    2004-01-01

    Budker Institute of Nuclear Physics has developed and produced RF generators, feeder lines and a control system for an industrial linear electron accelerator at Korean Atomic Energy Research Institute (KAERI, Daejeon, Korea). The accelerator is based on two superconducting RF cavities produced by CERN. Design energy of the accelerator is 10 MeV and design beam current is 10 mA. A 2 MeV injector for the accelerator was made by BINP earlier. Two-channel RF system of the accelerator operates at the frequency of 352 MHz in CW mode. Each channel has two-stage tetrode amplifier with output power of 50 kW, 100 W transistor preamplifier and the control system. Both tetrode stages have identical design. TH571B tetrode tubes produced by THALES (France) are used. Output power of 45 kW per channel was reached in an equivalent resistive load. Now BINP continues development of the accelerator. The energy of 11 MeV and the beam current of 1.9 mA were achieved. The amplitude of accelerating voltage was 4.5 MV in each cavity,...

  1. Extending PowerPack for Profiling and Analysis of High Performance Accelerator-Based Systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo; Chang, Hung-Ching; Song, Shuaiwen; Su, Chun-Yi; Meyer, Timmy; Mooring, John; Cameron, Kirk

    2014-12-01

    Accelerators offer a substantial increase in efficiency for high-performance systems offering speedups for computational applications that leverage hardware support for highly-parallel codes. However, the power use of some accelerators exceeds 200 watts at idle which means use at exascale comes at a significant increase in power at a time when we face a power ceiling of about 20 megawatts. Despite the growing domination of accelerator-based systems in the Top500 and Green500 lists of fastest and most efficient supercomputers, there are few detailed studies comparing the power and energy use of common accelerators. In this work, we conduct detailed experimental studies of the power usage and distribution of Xeon-Phi-based systems in comparison to the NVIDIA Tesla and at SandyBridge.

  2. About the scheme of the infrared FEL system for the accelerator based on HF wells

    Energy Technology Data Exchange (ETDEWEB)

    Kabanov, V.S.; Dzergach, A.I. [Moscow Radiotechnical Institute (Russian Federation)

    1995-12-31

    Accelerators, based on localization of plasmoids in the HF wells (RF traps) of the axially-symmetric electromagnetic field E {sub omn} in an oversized (m,n>>1) resonant system, can give accelerating gradients {approximately}100 kV/{lambda}, e.g. 10 GV/m if {lambda}=10 {mu}m. One of possible variants of HF feeding for these accelerators is based on using the powerful infrared FEL System with 2 frequencies. The corresponding FEL`s may be similar to the Los Alamos compact Advanced FEL ({lambda}{sub 1,2}{approximately}10 pm, e-beam energy {approximately}15 MeV, e-beam current {approximately}100 A). Their power is defined mainly by the HF losses in the resonant system of the supposed accelerator.

  3. Model-Driven Reengineering Legacy Software Systems to Web Services

    National Research Council Canada - National Science Library

    Cao, Fei; Bryant, Barrett R; Zhao, Wei; Burt, Carol C; Raje, Rajeev R; Olson, Andrew M; Auguston, Mikhail

    2005-01-01

    .... In this paper, we present a comprehensive, systematic, automatable approach toward reengineering legacy software systems to WS applications, rather than rewriting the whole legacy software system...

  4. General Purpose Data-Driven System Monitoring for Space Operations

    Data.gov (United States)

    National Aeronautics and Space Administration — Modern space propulsion and exploration system designs are becoming increasingly sophisticated and complex. Determining the health state of these systems using...

  5. First results of laser-proton acceleration with cryogenic hydrogen targets at the POLARIS laser

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Georg Alexander; Polz, Jens; Kloepfel, Diethard; Ziegler, Wolfgang; Keppler, Sebastian; Liebetrau, Hartmut; Hellwing, Marco [Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, 07743 Jena (Germany); Kalinin, Anton; Costa Fraga, Rui; Grisenti, Robert [Institut fuer Kernphysik, Goethe-Universitaet, 60438 Frankfurt am Main (Germany); Robinson, Alexander [Central Laser Facility, Rutherford-Appleton Laboratory, Chilton, Oxon., OX11 0QX (United Kingdom); Kessler, Alexander; Schorcht, Frank; Hornung, Marco [Helmholtz Institut Jena, 07743 Jena (Germany); Kaluza, Malte Christoph [Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, 07743 Jena (Germany); Helmholtz Institut Jena, 07743 Jena (Germany)

    2015-05-01

    For the first time on the POLARIS laser system, a laser-driven proton acceleration experiment with cryogenic hydrogen droplets and filaments has been performed. Most laser-driven proton acceleration experiments use target materials including metals, plastics or diamond-like carbon. Due to the multitude of ion species accelerated from such targets, understanding the acceleration processes becomes quite complicated. The use of liquid or frozen hydrogen targets reduces the accelerated species to protons only and additionally produces, due to the mass limited droplets or filaments, a higher acceleration field. The experimental setup and results, including isolated monoenergetic peaks in the high energy range of the proton spectra, are discussed.

  6. Plug-in module acceleration feedback control for fast steering mirror-based beam stabilization systems

    Science.gov (United States)

    Deng, Chao; Ren, Wei; Mao, Yao; Ren, Ge

    2017-08-01

    A plug-in module acceleration feedback control (Plug-In AFC) strategy based on the disturbance observer (DOB) principle is proposed for charge-coupled device (CCD)-based fast steering mirror (FSM) stabilization systems. In classical FSM tracking systems, dual-loop control (DLC), including velocity feedback and position feedback, is usually utilized to enhance the closed-loop performance. Due to the mechanical resonance of the system and CCD time delay, the closed-loop bandwidth is severely restricted. To solve this problem, cascade acceleration feedback control (AFC), which is a kind of high-precision robust control method, is introduced to strengthen the disturbance rejection property. However, in practical applications, it is difficult to realize an integral algorithm in an acceleration controller to compensate for the quadratic differential contained in the FSM acceleration model, resulting in a challenging controller design and a limited improvement. To optimize the acceleration feedback framework in the FSM system, different from the cascade AFC, the accelerometers are used to construct DOB to compensate for the platform vibrations directly. The acceleration nested loop can be plugged into the velocity loop without changing the system stability, and the controller design is quite simple. A series of comparative experimental results demonstrate that the disturbance rejection property of the CCD-based FSM can be effectively improved by the proposed approach.

  7. Intra-rater and inter-rater reliabilities of real-time acceleration gait analysis system.

    Science.gov (United States)

    Osaka, Hiroshi; Shinkoda, Koichi; Watanabe, Susumu; Fujita, Daisuke; Kobara, Kenichi; Yoshimura, Yosuke; Ito, Tomotaka

    2016-01-01

    The purposes of this study were to construct a real-time acceleration gait analysis system equipped with software to analyse real-time trunk acceleration during walking and to examine the intra-rater and inter-rater reliabilities of the this system. This system has been comprised of an accelerometer, an acceleration amplifier, a transmitter, two foot switches, a receiver and a personal computer installed with the real-time acceleration analysis software. The acceleration signals received were analysed using the real-time acceleration analysis software, and gait parameters were calculated. The subjects were 20 healthy individuals and two raters. The intra-rater and inter-rater reliabilities of the measurement results obtained from this system were examined by performing intraclass correlation coefficients (ICC) and Bland-Altman analysis. The intra-rater and inter-rater ICCs ranged from 0.61 to 0.92 in any gait parameters. In the Bland-Altman analysis, neither fixed nor proportional bias was found in any of the gait parameters. From the ICC and Bland-Altman analysis results, the gait measurement using this system clearly demonstrates that the intra-rater and inter-rater measurements had good reproducibility. Owing to this system, we can improve the clinical efficiency of gait analysis and gait training for physiotherapy. Implication for Rehabilitation This study focused on the advantage of a gait analysis method using an accelerometer and constructed a gait analysis system that calculates real-time gait parameters from trunk acceleration measurements during walking. The gait analysis using this system has good intra-rater and inter-rater reliabilities, and using this system can improve the clinical efficiency of gait analysis and gait training.

  8. Accelerated evolution of Fetuin-A (FETUA, also AHSG) is driven by positive Darwinian selection, not GC-biased gene conversion.

    Science.gov (United States)

    Döring, Yvonne; Zechner, Ulrich; Roos, Christian; Rosenkranz, David; Zischler, Hans; Herlyn, Holger

    2010-09-01

    Human Fetuin-A (FETUA, also termed AHSG) is a serum protein composed of two cystatin-like domains D1 and D2 of together 235 amino acids (aa) and an unrelated domain D3 of 114 aa. Though the protein plays a role in diverse physiological and pathological processes, comparably little is known about sequence evolution of FETUA. We therefore analyzed its molecular evolution on the basis of coding sequences of 16 primate species. Ratios of non-synonymous to synonymous substitution rates (d(n)/d(s)=omega) suggest that a previously reported acceleration of sequence evolution of exon 7, which encodes domain D3, is driven by positive selection instead of neutral evolution. Irrespective of the maximum likelihood model used, a remarkable 40% of codon sites is estimated to be positively selected in domain D3, with an average omega of 4.3. Analyses of GC/AT- and AT/GC-substitutions reveal that GC-biased gene conversion (gBGC) cannot explain the observed pattern. We thus reject the extended null model of molecular evolution (neutral evolution and gBGC) and conclude that positive Darwinian selection contributes to the sequence evolution of FETUA domain D3. Remarkably, domain D3 of human FETUA is characterized by a significant accumulation of proteolytic cleavage sites. Though speculative at present, the accelerated evolution of domain D3 might be due to the evolution of differential cleavage site patterns across primates reflecting different paths to achieve one goal, the decomposition of FETUA under pathological conditions. Present analyses use a PERL-script ("Substitution Bias Indicator", SBI) for the extraction of the numbers of GC/AT- and AT/GC-substitutions from supplemental results files of PAML analyses. The script is available upon request and the presented approach of testing the extended null hypothesis of molecular evolution can be transferred to every other protein coding locus. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Robust control of a class of chaotic and hyperchaotic driven systems

    Indian Academy of Sciences (India)

    2016-12-05

    Dec 5, 2016 ... main causes of the system's instability [1]. A well-known class of systems with discontinuous vector ... ity problem of synchronization error using a Lyapunov approach and solved using LMI tools and the well- ... From (1), the error dynamics between the driven sys- tem and the drive system can be written as.

  10. Analysis-Driven Design of Representations For Sensing-Action Systems

    Science.gov (United States)

    2017-10-01

    AFRL-RY-WP-TR-2017-0196 ANALYSIS-DRIVEN DESIGN OF REPRESENTATIONS FOR SENSING-ACTION SYSTEMS Stefano Soatto University of...Layered Sensing Exploitation Division This report is published in the interest of scientific and technical information exchange, and its...MM-YY) 2. REPORT TYPE 3. DATES COVERED (From - To) October 2017 Final 26 September 2011 – 30 June 2017 4. TITLE AND SUBTITLE ANALYSIS-DRIVEN DESIGN

  11. On the self-oscillation in a pulsed RF amplifying-accelerating system

    Science.gov (United States)

    Smirnov, A. V.

    2017-10-01

    A number of resonant accelerators of charged particles are fed by high power RF amplifiers loaded by resonant accelerating structures. Some of the accelerators such as linacs and racetrack microtrons are employed in self-oscillating mode using a positive feedback loop. That scheme allows a self-adjusted operation tolerable to significant changes in temperature and beam loading. However, in general such a system may develop instabilities. In this paper we consider a simplified model of an amplifier (e.g., a klystron) self-starting generation from noise and loaded by a resonant structure. Some typical transients including reflected power and influence of group delays are evaluated numerically.

  12. Towards cross-hierarchy simulation of collisionless driven reconnection in an open system

    OpenAIRE

    R., Horiuchi; H., Ohtani; A., Ishizawa

    2006-01-01

    The basic idea of a cross-hierarchy model for magnetic reconnection in an open system is proposed, where a microscopic system is surrounded by a macroscopic system and the interaction between the two systems is expressed by the plasma inflow and outflow through the system boundary. Collisionless driven reconnection in two-dimensional and three-dimensional open systems is demonstrated using an open particle simulation model developed as a microscopic part of a cross-hierarchy model. It is foun...

  13. Data-driven Applications for the Sun-Earth System

    Science.gov (United States)

    Kondrashov, D. A.

    2016-12-01

    Advances in observational and data mining techniques allow extracting information from the large volume of Sun-Earth observational data that can be assimilated into first principles physical models. However, equations governing Sun-Earth phenomena are typically nonlinear, complex, and high-dimensional. The high computational demand of solving the full governing equations over a large range of scales precludes the use of a variety of useful assimilative tools that rely on applied mathematical and statistical techniques for quantifying uncertainty and predictability. Effective use of such tools requires the development of computationally efficient methods to facilitate fusion of data with models. This presentation will provide an overview of various existing as well as newly developed data-driven techniques adopted from atmospheric and oceanic sciences that proved to be useful for space physics applications, such as computationally efficient implementation of Kalman Filter in radiation belts modeling, solar wind gap-filling by Singular Spectrum Analysis, and low-rank procedure for assimilation of low-altitude ionospheric magnetic perturbations into the Lyon-Fedder-Mobarry (LFM) global magnetospheric model. Reduced-order non-Markovian inverse modeling and novel data-adaptive decompositions of Sun-Earth datasets will be also demonstrated.

  14. A framework for semantic driven electronic examination system for ...

    African Journals Online (AJOL)

    The framework is implemented using Java programming language and a prototype of the proposed system is tested and compared with the existing system. Results show that words that are synonymous to any given correct answer are equally recognize as correct option. Hence, the e - examination system reliability, ...

  15. Design and Development Tools for the Systems Engineering Experience Accelerator - Part 3

    Science.gov (United States)

    2017-04-29

    Development Tools for the Systems Engineering Experience Accelerator – Part 3 Technical Report SERC-2017-TR-107 April 29, 2017 Principal...Stevens Institute of Technology: Peizhu Zhang Sponsor: Office of the DASD ( Systems Engineering ) Report No. SERC-2017-TR-107...April 29, 2017 ii Copyright © 2017 Stevens Institute of Technology, Systems Engineering

  16. Developing Systems Engineering Experience Accelerator (SEEA) Prototype and Roadmap -- Increment 4

    Science.gov (United States)

    2017-08-08

    Systems Engineering Experience Accelerator (SEEA) Prototype and Roadmap – Increment 4 Technical Report SERC-2017-TR-111 August 8, 2017...August 8, 2017 ii Copyright © 2017 Stevens Institute of Technology, Systems Engineering ...Research Center The Systems Engineering Research Center (SERC) is a federally funded University Affiliated Research Center managed by Stevens Institute

  17. Accelerated stochastic and hybrid methods for spatial simulations of reaction-diffusion systems

    OpenAIRE

    Rossinelli, D; Bayati, B; Koumoutsakos, P

    2008-01-01

    Spatial distributions characterize the evolution of reaction-diffusion models of several physical, chemical, and biological systems. We present two novel algorithms for the efficient simulation of these models: Spatial т-Leaping (Sт -Leaping), employing a unified acceleration of the stochastic simulation of reaction and diffusion, and Hybrid т-Leaping (Hт-Leaping), combining a deterministic diffusion approximation with a т-Leaping acceleration of the stochastic reactions. The algorithms are v...

  18. Accelerated atherosclerosis in patients with systemic autoimmune diseases

    NARCIS (Netherlands)

    De Leeuw, K.; Kallenberg, Cees; Bijl, Marc; Shoenfeld, Y.; Gershwin, M.E.; Shoenfeld, Y; Gershwin, ME

    2005-01-01

    Systemic autoimmune diseases such as systemic lupus erythematosus and Wegener's granulomatosis are associated with a significantly increased prevalence of cardiovascular disease (CVD) compared with age- and sex-matched controls. Many risk factors are involved in the pathogenesis of atherosclerosis,

  19. A Beam Interlock System for CERN High Energy Accelerators

    CERN Document Server

    Todd, Benjamin; Schmidt, R

    2006-01-01

    The Large Hadron Collider (LHC) at CERN (The European Organisation for Nuclear Research) is one of the largest and most complicated machines envisaged to date. The LHC has been conceived and designed over the course of the last 25 years and represents the cutting edge of accelerator technology with a collision energy of 14TeV, having a stored beam energy over 100 times more powerful than the nearest competitor. Commissioning of the machine is already nderway and operation with beam is intended for Autumn 2007, with 7TeV operation expected in 2008. The LHC is set to answer some of the fundemental questions in theoretical physics, colliding particles with such high energy that the inner workings of the quantum world can be revealed. Colliding particles together at such high energy makes very high demands on machine operation and protection. The specified beam energy requires strong magnetic fields that are made in superconducting dipole magnets, these magnets are kept only around two degrees above absolute zero...

  20. Modernization of the multipurpose accelerating system 'VGIK-1'

    CERN Document Server

    Yuferov, V B; Kosik, N A; Dryj, O S; Tkachev, V I

    2002-01-01

    The aim of VGIK-1 modernization is the possibility of metal surface processing by ion and electron irradiation, widening a range of applied energies and beam densities, vacuum condition control. This is reached by usage of two diodes, where one of them has isolated and defocussing magnetic system and another one has plasma emitter for extraction of ions electrons. There is also the system of plasma parameters control. Vacuum system includes the cryogenic, diffusion and titanium sorption pumps and mass-spectrometric system.

  1. Power supply regulation systems installed in the Fermilab accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Hays, S.; Wolff, D.; Pfeffer, H.

    1991-11-01

    A variety of current and voltage regulation systems have been installed in the Fermilab large magnet system. The four major systems employ different methods to achieve the desired degree of regulation. The methods include computer control and feedback, adaptive learning, precision (10ppm) current monitoring, and the use of feed-forward signals. This paper will explain each method used and present the measured regulation of the above systems. Also an overview of planned upgrades and improvements will be presented.

  2. Thermionic gun control system for the CEBAF (Continuous Electron Beam Accelerator Facility) injector

    Energy Technology Data Exchange (ETDEWEB)

    Pico, R.; Diamond, B.; Fugitt, J.; Bork, R.

    1989-01-01

    The injector for the CEBAF accelerator must produce a high-quality electron beam to meet the overall accelerator specifications. A Hermosa electron gun with a 2 mm-diameter cathode and a control aperture has been chosen as the electron source. This must be controlled over a wide range of operating conditions to meet the beam specifications and to provide flexibility for accelerator commissioning. The gun is controlled using Computer Automated Measurement and Control (CAMAC IEEE-583) technology. The system employs the CAMAC-based control architecture developed at CEBAF. The control system has been tested, and early operating data on the electron gun and the injector beam transport system has been obtained. This system also allows gun parameters to be stored at the operator location, without paralyzing operation. This paper describes the use of this computer system in the control of the CEBAF electron gun. 2 refs., 6 figs., 1 tab.

  3. AEi systems designing power sstem for world's largest particle accelerator

    CERN Multimedia

    Weinberg, Lee

    2007-01-01

    "AEi Systems, a world leader in power systems analysis and design, announced today that the Large Hadron Collider (LHC) at CERN (the European Centre for Nuclear Research) near Geneva, Switzerland, has engaged AEi Systems to design and develop a radiation-hard power supply for CERN's giant ATLAS particle detector." (1 page)

  4. Accelerator-driven sub-critical reactor system (ADS) for nuclear ...

    Indian Academy of Sciences (India)

    made plutonium are the two key elements that are serving as nuclear fuel. Nuclear power presently constitutes about 17% of the total electric power generation in the world from about 430 operating reactors. Although this figure of global nuclear energy generation appears modest, the share of nuclear electricity in several ...

  5. Tunnel radio communications system at Stanford Linear Accelerator Center

    Energy Technology Data Exchange (ETDEWEB)

    Struven, W.C.

    1980-07-01

    A unique single frequency, dual daisy chain tunnel radio communication system has been developed for use in our new Positron-Electron Storage Ring. Communications are possible between portables in the underground ring and between a portable in the ring and all control rooms on the site. The system is designed as a wide band facility and therefore can carry many simplex and duplex transmissions. This system utilizes TV twinlead as a distributed antenna and repeater amplifiers to cover more than 7000 feet of underground tunnel. The design philosophy, tests and initial design are discussed and contrasted with the final implementation of the system. Future uses of the system are discussed.

  6. Model-Driven Test Generation of Distributed Systems

    Science.gov (United States)

    Easwaran, Arvind; Hall, Brendan; Schweiker, Kevin

    2012-01-01

    This report describes a novel test generation technique for distributed systems. Utilizing formal models and formal verification tools, spe cifically the Symbolic Analysis Laboratory (SAL) tool-suite from SRI, we present techniques to generate concurrent test vectors for distrib uted systems. These are initially explored within an informal test validation context and later extended to achieve full MC/DC coverage of the TTEthernet protocol operating within a system-centric context.

  7. Continuous Energy Improvement in Motor Driven Systems - A Guidebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert A. McCoy and John G. Douglass

    2014-02-01

    This guidebook provides a step-by-step approach to developing a motor system energy-improvement action plan. An action plan includes which motors should be repaired or replaced with higher efficiency models, recommendations on maintaining a spares inventory, and discussion of improvements in maintenance practices. The guidebook is the successor to DOE’s 1997 Energy Management for Motor Driven Systems. It builds on its predecessor publication by including topics such as power transmission systems and matching driven equipment to process requirements in addition to motors.

  8. Reduced equations of motion for quantum systems driven by diffusive Markov processes.

    Science.gov (United States)

    Sarovar, Mohan; Grace, Matthew D

    2012-09-28

    The expansion of a stochastic Liouville equation for the coupled evolution of a quantum system and an Ornstein-Uhlenbeck process into a hierarchy of coupled differential equations is a useful technique that simplifies the simulation of stochastically driven quantum systems. We expand the applicability of this technique by completely characterizing the class of diffusive Markov processes for which a useful hierarchy of equations can be derived. The expansion of this technique enables the examination of quantum systems driven by non-Gaussian stochastic processes with bounded range. We present an application of this extended technique by simulating Stark-tuned Förster resonance transfer in Rydberg atoms with nonperturbative position fluctuations.

  9. Confidentiality issues within a clinical information system: moving from data-driven to event-driven design.

    Science.gov (United States)

    Staccini, P; Joubert, M; Fieschi, D; Fieschi, M

    1999-12-01

    Within a hospital, the moving of medical information systems from retrospective data-gathering methods to prospective clinical information systems raises the question of the confidentiality of patient data. A method of improving the traditional matrix model usually used to achieve access controls is described. The event-driven model refers to the way a security system ensures that a given user has a valid "need-to" relationship to a given patient. Events are defined as the occurrence of specific data that trigger the creation or the updating of the relationship between the identity of a user and the identity of a patient (e.g., admission, discharge, transfer, prescription, and report). The creation and the deletion of the relationships between users and patients are based on numerous repositories and working lists of patients. This implementation requires an organization of the hospital activities which is able to manage, in a real-time manner, those repositories as closely as possible to the steps occurring during the patient's care process. Although this approach seems to reasonably fit the dynamic of the care process, it adds significant organizational constraints.

  10. a framework for semantic driven electronic examination system for ...

    African Journals Online (AJOL)

    HOD

    The framework is implemented using Java programming language and a prototype of the proposed system is tested and ... through the computer system where responses are electronically recorded and assessed [13]. ..... Pages (JSP) and Structural Query Language (SQL) Server database technology. Unlike, the existing e- ...

  11. Intermittent lag synchronization in a driven system of coupled ...

    Indian Academy of Sciences (India)

    Paseo de Las Monta˜nas, Lagos del Moreno 47460, Jalisco, Mexico. E-mail: apisarch@cio.mx. Abstract. We study intermittent lag synchronization in a system of two identical mu- tually coupled Duffing oscillators with parametric modulation in one of them. This phe- nomenon in a periodically forced system can be seen as ...

  12. Operational Experience of Cooling Water Systems for Accelerator Components at PLS

    CERN Document Server

    Kim, Kyungryul; Kim, Young-Chan; Lee, Bongho; Sik Han, Hong; Soo Ko In; Wha Chung, Chin

    2005-01-01

    The cooling water system has been utilized for absorbing heat generated by a multitude of electromagnetic power delivering networks at PLS. The separate cooling water distribution systems for the storage ring, beam transport line and linear accelerator have been operated with a different operating temperature of supplying water. All water used for heat removal from the accelerator components are deionised and filtered to provide with over 2 MO-cm specific resistance. The operating pressures and flows of input water are also controlled with flow balancing scheme at a specified range. The operating temperature of components in the accelerator is sustained as tight as below ±0.1 deg C to minimize the influence of temperature fluctuation on the beam energy and stability. Although the PLS cooling systems were initially installed with a high degree of flexibility to allow for easy maintenance, a number of system improvements have been employed to enhance operational reliability and to incorporate the newly...

  13. Database Foundation For The Configuration Management Of The CERN Accelerator Controls Systems

    CERN Document Server

    Zaharieva, Z; Peryt, M

    2011-01-01

    The Controls Configuration Database (CCDB) and its interfaces have been developed over the last 25 years in order to become nowadays the basis for the Configuration Management of the Controls System for all accelerators at CERN. The CCDB contains data for all configuration items and their relationships, required for the correct functioning of the Controls System. The configuration items are quite heterogeneous, depicting different areas of the Controls System – ranging from 3000 Front-End Computers, 75 000 software devices allowing remote control of the accelerators, to valid states of the Accelerators Timing System. The article will describe the different areas of the CCDB, their interdependencies and the challenges to establish the data model for such a diverse configuration management database, serving a multitude of clients. The CCDB tracks the life of the configuration items by allowing their clear identification, triggering of change management processes as well as providing status accounting and aud...

  14. Biocellion: accelerating computer simulation of multicellular biological system models.

    Science.gov (United States)

    Kang, Seunghwa; Kahan, Simon; McDermott, Jason; Flann, Nicholas; Shmulevich, Ilya

    2014-11-01

    Biological system behaviors are often the outcome of complex interactions among a large number of cells and their biotic and abiotic environment. Computational biologists attempt to understand, predict and manipulate biological system behavior through mathematical modeling and computer simulation. Discrete agent-based modeling (in combination with high-resolution grids to model the extracellular environment) is a popular approach for building biological system models. However, the computational complexity of this approach forces computational biologists to resort to coarser resolution approaches to simulate large biological systems. High-performance parallel computers have the potential to address the computing challenge, but writing efficient software for parallel computers is difficult and time-consuming. We have developed Biocellion, a high-performance software framework, to solve this computing challenge using parallel computers. To support a wide range of multicellular biological system models, Biocellion asks users to provide their model specifics by filling the function body of pre-defined model routines. Using Biocellion, modelers without parallel computing expertise can efficiently exploit parallel computers with less effort than writing sequential programs from scratch. We simulate cell sorting, microbial patterning and a bacterial system in soil aggregate as case studies. Biocellion runs on x86 compatible systems with the 64 bit Linux operating system and is freely available for academic use. Visit http://biocellion.com for additional information. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Biocellion: accelerating computer simulation of multicellular biological system models

    Science.gov (United States)

    Kang, Seunghwa; Kahan, Simon; McDermott, Jason; Flann, Nicholas; Shmulevich, Ilya

    2014-01-01

    Motivation: Biological system behaviors are often the outcome of complex interactions among a large number of cells and their biotic and abiotic environment. Computational biologists attempt to understand, predict and manipulate biological system behavior through mathematical modeling and computer simulation. Discrete agent-based modeling (in combination with high-resolution grids to model the extracellular environment) is a popular approach for building biological system models. However, the computational complexity of this approach forces computational biologists to resort to coarser resolution approaches to simulate large biological systems. High-performance parallel computers have the potential to address the computing challenge, but writing efficient software for parallel computers is difficult and time-consuming. Results: We have developed Biocellion, a high-performance software framework, to solve this computing challenge using parallel computers. To support a wide range of multicellular biological system models, Biocellion asks users to provide their model specifics by filling the function body of pre-defined model routines. Using Biocellion, modelers without parallel computing expertise can efficiently exploit parallel computers with less effort than writing sequential programs from scratch. We simulate cell sorting, microbial patterning and a bacterial system in soil aggregate as case studies. Availability and implementation: Biocellion runs on x86 compatible systems with the 64 bit Linux operating system and is freely available for academic use. Visit http://biocellion.com for additional information. Contact: seunghwa.kang@pnnl.gov PMID:25064572

  16. Optical response in a laser-driven quantum pseudodot system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, D. Gul [Physics Department, Graduate School of Natural and Applied Sciences, Dokuz Eylül University, 35390 Izmir (Turkey); Sakiroglu, S., E-mail: serpil.sakiroglu@deu.edu.tr [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey); Ungan, F.; Yesilgul, U. [Department of Optical Engineering, Faculty of Technology, Cumhuriyet University, 58140 Sivas (Turkey); Kasapoglu, E. [Physics Department, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Sari, H. [Department of Primary Education, Faculty of Education, Cumhuriyet University, 58140 Sivas (Turkey); Sokmen, I. [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey)

    2017-03-15

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  17. L-systems driven self-reconfiguration of modular robots

    Directory of Open Access Journals (Sweden)

    Dongyang Bie

    2016-10-01

    Full Text Available In the domain of modular self-reconfigurable robotic systems, self-reconfiguration is known to be a highly challenging task. This article presents a novel algorithm for distributed self-reconfiguration by combining cellular automata and L-systems. Cellular automata is used to handle the relative motion planning of decentralized modules. L-systems are introduced to provide a topological description for the target configuration. The turtle interpretation is extended to modular robotics to generate local predictions for distributed modules from global description. Local predictions spread out in the system through gradient propagation. Modules, using cellular automata rules managing local motion, climb gradient to the expanding fronts for constructing global configurations. Both simulations and experiments have demonstrated the practical effectiveness of the proposed algorithm.

  18. Towards Ontology-Driven Information Systems: Guidelines to the Creation of New Methodologies to Build Ontologies

    Science.gov (United States)

    Soares, Andrey

    2009-01-01

    This research targeted the area of Ontology-Driven Information Systems, where ontology plays a central role both at development time and at run time of Information Systems (IS). In particular, the research focused on the process of building domain ontologies for IS modeling. The motivation behind the research was the fact that researchers have…

  19. Model Driven Development of m-Health Systems (with a Touch of Formality)

    NARCIS (Netherlands)

    Jones, Valerie M.

    We propose a model driven design and development methodology augmented with formal validation and verification (V&V) for the development of mobile health systems. Systems which deliver healthcare services remotely should be developed using robust and trusted engineering technologies. The methodology

  20. Model Driven Development of m-Health Systems (with a Touch of Formality)

    NARCIS (Netherlands)

    Jones, Valerie M.

    2006-01-01

    We propose a model driven design and development methodology augmented with formal validation and verification (V&V) for the development of mobile health systems. Systems which deliver healthcare services remotely should be developed using robust and trusted engineering technologies. The methodology

  1. Energizing a Large Urban System: Reform through a Standards Driven Model.

    Science.gov (United States)

    Robbins, Stephen B.

    This paper describes the District of Columbia Public School System (DCPS); articulates challenges it faced prior to standards based reform; presents strategies for reforming large urban systems' health and physical education (HPE) programs; and notes strategies for incorporating a standards-based performance-driven model. DCPS reading and math…

  2. Analysis of Fuel Cell Driven Ground Source Heat Pump Systems in Community Buildings

    Directory of Open Access Journals (Sweden)

    Jong-Keun Shin

    2013-05-01

    Full Text Available In the present study, a fuel cell driven ground source heat pump (GSHP system is applied in a community building and heat pump system performance is analyzed by computational methods. Conduction heat transfer between the brine pipe and ground is analyzed by TEACH code in order to predict the performance of the heat pump system. The predicted coefficient of performance (COP of the heat pump system and the energy cost were compared with the variation of the location of the objective building, the water saturation rate of the soil, and the driven powers of the heat pump system. Compared to the late-night electricity driven system, a significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system. This is due to the low cost of electricity production of the fuel cell system and to the application of the recovered waste heat generated during the electricity production process to the heating of the community building.

  3. Classification Systems, their Digitization and Consequences for Data-Driven Decision Making

    DEFF Research Database (Denmark)

    Stein, Mari-Klara; Newell, Sue; Galliers, Robert D.

    2013-01-01

    Classification systems are foundational in many standardized software tools. This digitization of classification systems gives them a new ‘materiality’ that, jointly with the social practices of information producers/consumers, has significant consequences on the representational quality of such ...... and the foundational role of representational quality in understanding the success and consequences of data-driven decision-making....

  4. Microcontroller-driven fluid-injection system for atomic force microscopy.

    Science.gov (United States)

    Kasas, S; Alonso, L; Jacquet, P; Adamcik, J; Haeberli, C; Dietler, G

    2010-01-01

    We present a programmable microcontroller-driven injection system for the exchange of imaging medium during atomic force microscopy. Using this low-noise system, high-resolution imaging can be performed during this process of injection without disturbance. This latter circumstance was exemplified by the online imaging of conformational changes in DNA molecules during the injection of anticancer drug into the fluid chamber.

  5. Development of an automated system for the operation of an electron beam accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir L.; Moura, João A.; Calvo, Wilson Ap. Parejo, E-mail: somessar@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    Electron beam accelerators are used in many applications, such as basic physical research, chemistry, medicine, molecular biology, microelectronics, agriculture and industry, among others. The majority of the accelerators have electrons from a hot tungsten filament and their energy is increased as it passes through an electric field in the vacuum chamber. For industrial purposes, the most common model is Dynamitrons®. At IPEN-CNEN/SP, there is an electron beam accelerator Dynamitron® Type (Manufactured by RDI- Radiation Dynamics Inc., 1978) model DC1500/25/4. The technology applied was available in the 60's and 70's, but, nowadays is obsolete. Moreover, there are not original spare parts for this equipment any longer. The aim of this work is to develop a nationalized automated operation system for the accelerator, to replace the old equipment. (author)

  6. A Unique U.S. Approach for Accelerator-Driven Warm Dense Matter Research--Preliminary Report

    Energy Technology Data Exchange (ETDEWEB)

    Logan, B G; Davidson, R C; Barnard, J J; Lee, R

    2004-12-22

    The warm density matter regime of high energy density physics [1, 2, 3] has a high scientific discovery potential for the properties of plasmas at high densities and pressures and at moderate temperatures (kT) in which the Coulomb interaction energy between plasma particles exceed kT. This leads to correlations in the plasma characterized by the dimensionless ''coupling'' parameter {Lambda} > 1, where {Lambda} is defined by {Lambda} = q{sup 2}n{sup 1/3}/kT. Here q is the effective ion charge and n the ion density. Strongly-coupled plasmas with {Lambda} > 1 are difficult to study analytically and by numerical simulation. Many astrophysical systems (e.g., brown dwarfs, and giant planets) and inertial fusion plasmas in the beginning stages of compression fall into this regime. There is an opportunity to develop improved understanding and models through accurate measurements of properties in the large parameter space of temperature and density where data is currently limited or non-existent. X-ray free-electron lasers (Fourth generation light sources), ultra-short pulse and high energy optical lasers, pulsed-power z-pinch x-ray sources, and high explosives are all capable of producing warm dense matter conditions at various temperatures, pressures, and sample sizes. Therefore, the challenge is not how to create warm dense matter conditions, but to create it so that it's fundamental properties can be best studied. The goal is to advance this field of science through a variety of complementary facilities and methods which offer several combinations of desirable attributes: Precise control and uniformity of energy deposition; Large sample sizes compared to diagnostic resolution volumes; A benign environment for diagnostics (low debris and radiation background); High shot rates (10/hour to 1/second) and multiple beamlines/target chambers; and Sites with easy access for broad participation by university scientists and students; and with the

  7. Data-driven design of fault diagnosis and fault-tolerant control systems

    CERN Document Server

    Ding, Steven X

    2014-01-01

    Data-driven Design of Fault Diagnosis and Fault-tolerant Control Systems presents basic statistical process monitoring, fault diagnosis, and control methods, and introduces advanced data-driven schemes for the design of fault diagnosis and fault-tolerant control systems catering to the needs of dynamic industrial processes. With ever increasing demands for reliability, availability and safety in technical processes and assets, process monitoring and fault-tolerance have become important issues surrounding the design of automatic control systems. This text shows the reader how, thanks to the rapid development of information technology, key techniques of data-driven and statistical process monitoring and control can now become widely used in industrial practice to address these issues. To allow for self-contained study and facilitate implementation in real applications, important mathematical and control theoretical knowledge and tools are included in this book. Major schemes are presented in algorithm form and...

  8. Phase and amplitude control system for Stanford Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, S.J.

    1983-09-26

    The computer controlled phase and amplitude detection system measures the instantaneous phase and amplitude of a 1 micro-second 2856 MHz rf pulse at a 180 Hz rate. This will be used for phase feedback control, and also for phase and amplitude jitter measurement. The program, which was originally written by John Fox and Keith Jobe, has been modified to improve the function of the system. The software algorithms used in the measurement are described, as is the performance of the prototype phase and amplitude detector system.

  9. Software architecture of the SSC accelerator systems string test

    Science.gov (United States)

    Corker, Valerie; Kallas, Nick; Lee, Sylvester; Murray, Doug; Wang, Judy; Zatopek, John

    1994-12-01

    The software architecture is described for the data acquisition and control systems implemented to support a full cell test of collider arc section lattice components. The discussion is divided into descriptions of the software applications for process controls, operator interfaces, and data acquisition, archiving, and analysis. Specifics are presented for the distributed implementation of the acquisition, archiving, and analysis services, and their integration with a commercial Relational Database Management System (RDBMS). The relational table structure used in the RDBMS is explained. Finally, system performance, lessons learned, and future plans are summarized.

  10. Test-driven modeling and development of cloud-enabled cyber-physical smart systems

    DEFF Research Database (Denmark)

    Munck, Allan; Madsen, Jan

    2017-01-01

    Embedded products currently tend to evolve into large and complex smart systems where products are enriched with services through clouds and other web technologies. The complex characteristics of smart systems make it very difficult to guarantee functionality, safety, security and performance....... Using test-driven modeling (TDM) is likely to be the best way to design smart systems such that these qualities are ensured. However, the TDM methods that are applied to development of simpler systems do not scale to smart systems because the modeling technologies cannot handle the complexity and size...... of the systems. In this paper, we present a method for test-driven modeling that scales to very large and complex systems. The method uses a combination of formal verification of basic interactions, simulations of complex scenarios, and mathematical forecasting to predict system behavior and performance. We...

  11. Test-Driven, Model-Based Systems Engineering

    DEFF Research Database (Denmark)

    Munck, Allan

    . This thesis concerns methods for identifying, selecting and implementing tools for various aspects of model-based systems engineering. A comprehensive method was proposed that include several novel steps such as techniques for analyzing the gap between requirements and tool capabilities. The method...... was verified with good results in two case studies for selection of a traceability tool (single-tool scenario) and a set of modeling tools (multi-tool scenarios). Models must be subjected to testing to allow engineers to predict functionality and performance of systems. Test-first strategies are known......Hearing systems have evolved over many years from simple mechanical devices (horns) to electronic units consisting of microphones, amplifiers, analog filters, loudspeakers, batteries, etc. Digital signal processors replaced analog filters to provide better performance end new features. Central...

  12. Modeling of accelerator systems and experimental verification of Quarter-Wave Resonator steering

    Science.gov (United States)

    Benatti, Carla

    Increasingly complicated accelerator systems depend more and more on computing power and computer simulations for their operation as progress in the field has led to cutting-edge advances that require finer control and better understanding to achieve optimal performance. Greater ambitions coupled with the technical complexity of today's state-of-the-art accelerators necessitate corresponding advances in available accelerator modeling resources. Modeling is a critical component of any field of physics, accelerator physics being no exception. It is extremely important to not only understand the basic underlying physics principles but to implement this understanding through the development of relevant modeling tools that provide the ability to investigate and study various complex effects. Moreover, these tools can lead to new insight and applications that facilitate control room operations and enable advances in the field that would not otherwise be possible. The ability to accurately model accelerator systems aids in the successful operation of machines designed specifically to deliver beams to experiments across a wide variety of fields, ranging from material science research to nuclear astrophysics. One such accelerator discussed throughout this work is the ReA facility at the National Superconducting Cyclotron Laboratory (NSCL) which re-accelerates rare isotope beams for nuclear astrophysics experiments. A major component of the ReA facility, as well as the future Facility for Rare Isotope Beams (FRIB) among other accelerators, is the Quarter-Wave Resonator (QWR), a coaxial accelerating cavity convenient for efficient acceleration of low-velocity particles. This device is very important to model accurately as it operates in the critical low-velocity region where the beam's acceleration gains are proportionally larger than they are through the later stages of acceleration. Compounding this matter, QWRs defocus the beam, and are also asymmetric with respect to the

  13. An Optimum Switching Criterion for a Third-order Contactor Acceleration Control System

    Science.gov (United States)

    Passera, Anthony L; Willoh, Ross G , R

    1956-01-01

    A switching criterion for optimum performance of a third-order contractor acceleration control system having complex roots is presented. Analytical and analog-computer methods are utilized to determine this criterion. The resulting optimum transient responses are presented and compared with those of an equivalent linear system.

  14. A Social Bookmarking System to Support Cluster Driven Archival Arrangement

    NARCIS (Netherlands)

    Bron, M.; Wang, S.; van der Werf, T.; de Rijke, M.

    2014-01-01

    Cultural heritage materials are increasingly being made available through standard search facilities. However, it is challenging to au- tomatically organize these materials in a way that is well aligned with users' specific interests. We report on the development of a social bookmaking system to

  15. Density-Driven segregation in Binary and Ternary Granular Systems

    NARCIS (Netherlands)

    Windows-Yule, Kit; Parker, David

    2015-01-01

    We present a first experimental study of density-induced segregation within a three-dimensional, vibrofluidised, ternary granular system. Using Positron Emission Particle Tracking (PEPT), we study the steady-state particle distributions achieved by binary and ternary granular beds under a variety of

  16. Scaling behaviour of pressure-driven micro-hydraulic systems

    NARCIS (Netherlands)

    Tas, Niels Roelof; Lammerink, Theodorus S.J.; Berenschot, Johan W.; Elwenspoek, Michael Curt; van den Berg, Albert

    2002-01-01

    This paper presents a lumped network approach for the modelling and design of micro-hydraulic systems. A hydraulic oscillator has been built consisting of hydraulic resistors, capacitors and transistors (pressure controlled valves). The scaling of micro-hydraulic networks consisting of linear

  17. Schedulability-Driven Communication Synthesis for Time Triggered Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2006-01-01

    We present an approach to static priority preemptive process scheduling for the synthesis of hard real-time distributed embedded systems where communication plays an important role. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication ...

  18. Synchronization in driven chaotic systems: Diagnostics and bifurcations

    DEFF Research Database (Denmark)

    Vadivasova, T.E.; Balanov, A.G.; Sosnovtseva, O.V.

    1999-01-01

    We investigate generic aspects of chaos synchronization in an externally forced Rössler system. By comparing different diagnostic methods, we show the existence of a well-defined cut-off of synchronization associated with the transition from weak to fully developed chaos. Two types of chaotic...... behavior, differing by the number of vanishing Lyapunov exponents, are observed outside the synchronization regime....

  19. Entropy-Driven Phase Transitions in Colloidal Systems

    NARCIS (Netherlands)

    Ni, R.

    2012-01-01

    This thesis can be divided into two independent parts. In the first part of this thesis, we focus on studying the kinetic pathways of nucleation in colloidal systems. In Chapter 2, we briefly introduce the relevant theory of nucleation, i.e., classic nucleation theory. Then in Chapter 3, we

  20. Performance Assessment of a Large Scale Pulsejet- Driven Ejector System

    Science.gov (United States)

    Paxson, Daniel E.; Litke, Paul J.; Schauer, Frederick R.; Bradley, Royce P.; Hoke, John L.

    2006-01-01

    Unsteady thrust augmentation was measured on a large scale driver/ejector system. A 72 in. long, 6.5 in. diameter, 100 lb(sub f) pulsejet was tested with a series of straight, cylindrical ejectors of varying length, and diameter. A tapered ejector configuration of varying length was also tested. The objectives of the testing were to determine the dimensions of the ejectors which maximize thrust augmentation, and to compare the dimensions and augmentation levels so obtained with those of other, similarly maximized, but smaller scale systems on which much of the recent unsteady ejector thrust augmentation studies have been performed. An augmentation level of 1.71 was achieved with the cylindrical ejector configuration and 1.81 with the tapered ejector configuration. These levels are consistent with, but slightly lower than the highest levels achieved with the smaller systems. The ejector diameter yielding maximum augmentation was 2.46 times the diameter of the pulsejet. This ratio closely matches those of the small scale experiments. For the straight ejector, the length yielding maximum augmentation was 10 times the diameter of the pulsejet. This was also nearly the same as the small scale experiments. Testing procedures are described, as are the parametric variations in ejector geometry. Results are discussed in terms of their implications for general scaling of pulsed thrust ejector systems

  1. Mission-driven Resource Management for Reconfigurable Sensing Systems

    NARCIS (Netherlands)

    De Groot, T.H.

    2015-01-01

    The spectrum of threats imposed upon modern society has drastically widened in the last decades. One of the required security means is sensor systems. There exist many types of sensors and their capabilities vary, but some of them are reconfigurable and able to provide many functions. Such sensors

  2. On designing a control system for a new generation of accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Schaller, S.C.; Schultz, D.E.

    1987-01-01

    A well-conceived plan of attack is essential to the task of designing a control system for a large accelerator. Several aspects of such a plan have been investigated during recent work at LAMPF on design strategies for an Advanced Hadron Facility control system. Aspects discussed in this paper include: identification of requirements, creation and enforcement of standards, interaction with users, consideration of commercial controls products, integration with existing control systems, planning for continual change, and establishment of design reviews. We emphasize the need for the controls group to acquire and integrate accelerator design information from the start of the design process. We suggest that a controls design for a new generation of accelerators be done with a new generation of software tools. 12 refs.

  3. LHC Report: Rehearsing the LHC accelerator systems for the Run 2 start-up with beam

    CERN Multimedia

    Reyes Alemany Fernandez

    2015-01-01

    While the commissioning of the superconducting circuits is ongoing, great care is also being taken to make sure that the other key LHC accelerator systems are qualified for beam. Since spring 2014, small-scale integration tests on the accelerator systems have been scheduled and carried out successfully to exercise them fully and thoroughly debug their multiple interfaces. The LHC Operations team leads this activity in tight collaboration with the equipment experts and the essential support of the Accelerator Controls group. The tests start once individual system qualification has been performed by the equipment owners and they are ready to be handed over to operations. These tests performed by Operations are called dry runs – dry because they are performed without beam – and they are carried out from the CERN Control Centre (CCC) using the same high-level software applications that will be used during beam operation. The dry runs are the first step towards a global integration test ...

  4. RBAC Driven Least Privilege Architecture For Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hull, Julie [Honeywell International Inc., Golden Valley, MN (United States); Markham, Mark [Honeywell International Inc., Golden Valley, MN (United States)

    2014-01-25

    The concept of role based access control (RBAC) within the IT environment has been studied by researchers and was supported by NIST (circa 1992). This earlier work highlighted the benefits of RBAC which include reduced administrative workload and policies which are easier to analyze and apply. The goals of this research were to expand the application of RBAC in the following ways. Apply RBAC to the control systems environment: The typical RBAC model within the IT environment is used to control a user’s access to files. Within the control system environment files are replaced with measurement (e.g., temperature) and control (e.g. valve) points organized as a hierarchy of control assets (e.g. a boiler, compressor, refinery unit). Control points have parameters (e.g., high alarm limit, set point, etc.) associated with them. The RBAC model is extended to support access to points and their parameters based upon roles while at the same time allowing permissions for the points to be defined at the asset level or point level directly. In addition, centralized policy administration with distributed access enforcement mechanisms was developed to support the distributed architecture of distributed control systems and SCADA; Extend the RBAC model to include access control for software and devices: The established RBAC approach is to assign users to roles. This work extends that notion by first breaking the control system down into three layers 1) users, 2) software and 3) devices. An RBAC model is then created for each of these three layers. The result is that RBAC can be used to define machine-to-machine policy enforced via the IP security (IPsec) protocol. This highlights the potential to use RBAC for machine-to-machine connectivity within the internet of things; and Enable dynamic policy based upon the operating mode of the system: The IT environment is generally static with respect to policy. However, large cyber physical systems such as industrial controls have various

  5. Measurable Control System Security through Ideal Driven Technical Metrics

    Energy Technology Data Exchange (ETDEWEB)

    Miles McQueen; Wayne Boyer; Sean McBride; Marie Farrar; Zachary Tudor

    2008-01-01

    The Department of Homeland Security National Cyber Security Division supported development of a small set of security ideals as a framework to establish measurable control systems security. Based on these ideals, a draft set of proposed technical metrics was developed to allow control systems owner-operators to track improvements or degradations in their individual control systems security posture. The technical metrics development effort included review and evaluation of over thirty metrics-related documents. On the bases of complexity, ambiguity, or misleading and distorting effects the metrics identified during the reviews were determined to be weaker than necessary to aid defense against the myriad threats posed by cyber-terrorism to human safety, as well as to economic prosperity. Using the results of our metrics review and the set of security ideals as a starting point for metrics development, we identified thirteen potential technical metrics - with at least one metric supporting each ideal. Two case study applications of the ideals and thirteen metrics to control systems were then performed to establish potential difficulties in applying both the ideals and the metrics. The case studies resulted in no changes to the ideals, and only a few deletions and refinements to the thirteen potential metrics. This led to a final proposed set of ten core technical metrics. To further validate the security ideals, the modifications made to the original thirteen potential metrics, and the final proposed set of ten core metrics, seven separate control systems security assessments performed over the past three years were reviewed for findings and recommended mitigations. These findings and mitigations were then mapped to the security ideals and metrics to assess gaps in their coverage. The mappings indicated that there are no gaps in the security ideals and that the ten core technical metrics provide significant coverage of standard security issues with 87% coverage. Based

  6. Solvable Family of Driven-Dissipative Many-Body Systems.

    Science.gov (United States)

    Foss-Feig, Michael; Young, Jeremy T; Albert, Victor V; Gorshkov, Alexey V; Maghrebi, Mohammad F

    2017-11-10

    Exactly solvable models have played an important role in establishing the sophisticated modern understanding of equilibrium many-body physics. Conversely, the relative scarcity of solutions for nonequilibrium models greatly limits our understanding of systems away from thermal equilibrium. We study a family of nonequilibrium models, some of which can be viewed as dissipative analogues of the transverse-field Ising model, in that an effectively classical Hamiltonian is frustrated by dissipative processes that drive the system toward states that do not commute with the Hamiltonian. Surprisingly, a broad and experimentally relevant subset of these models can be solved efficiently. We leverage these solutions to compute the effects of decoherence on a canonical trapped-ion-based quantum computation architecture, and to prove a no-go theorem on steady-state phase transitions in a many-body model that can be realized naturally with Rydberg atoms or trapped ions.

  7. Future cooperative communication systems driven by social mobile networks

    DEFF Research Database (Denmark)

    Blázovics, L.; Varga, C.; Bamford, W.

    2011-01-01

    In this work we are underlining the importance of social mobile networks for upcoming cooperative communication systems. The assumption of this work is that future mobile communication systems will incorporate user cooperation, i.e. a combination of cellular access in parallel with ongoing short...... range links to the neighboring devices. It has been shown that user cooperation enables higher data rates, better spectral efficiencies, and reduces the energy consumption of the mobile unit. In this work the social mobile networks are identified to be a fertile ground to facilitate the cooperative use...... cases. By the example of the Gedda-Headz gaming community, possible links between cooperative mobile communication and social mobile networks are shown....

  8. Solvable Family of Driven-Dissipative Many-Body Systems

    Science.gov (United States)

    Foss-Feig, Michael; Young, Jeremy T.; Albert, Victor V.; Gorshkov, Alexey V.; Maghrebi, Mohammad F.

    2017-11-01

    Exactly solvable models have played an important role in establishing the sophisticated modern understanding of equilibrium many-body physics. Conversely, the relative scarcity of solutions for nonequilibrium models greatly limits our understanding of systems away from thermal equilibrium. We study a family of nonequilibrium models, some of which can be viewed as dissipative analogues of the transverse-field Ising model, in that an effectively classical Hamiltonian is frustrated by dissipative processes that drive the system toward states that do not commute with the Hamiltonian. Surprisingly, a broad and experimentally relevant subset of these models can be solved efficiently. We leverage these solutions to compute the effects of decoherence on a canonical trapped-ion-based quantum computation architecture, and to prove a no-go theorem on steady-state phase transitions in a many-body model that can be realized naturally with Rydberg atoms or trapped ions.

  9. Delay-driven irregular spatiotemporal patterns in a plankton system.

    Science.gov (United States)

    Tian, Canrong; Zhang, Lai

    2013-07-01

    An inhomogeneous distribution of species density over physical space is a widely observed scenario in plankton systems. Understanding the mechanisms resulting in these spatial patterns is a central topic in plankton ecology. In this paper we explore the impact of time delay on spatiotemporal patterns in a prey-predator plankton system. We find that time delay can trigger the emergence of irregular spatial patterns via a Hopf bifurcation. Moreover, a phase transition from a regular spiral pattern to an irregular one was observed and the latter gradually replaced the former and persisted indefinitely. The characteristic length of the emergent spatial pattern is consistent with the scale of plankton patterns observed in field studies.

  10. Design Tools for Dynamic, Data-Driven, Stream Mining Systems

    Science.gov (United States)

    2015-01-01

    1 Figure 1.1: An illustration of the design space for adaptive stream mining systems. science (e.g., water management and seismic monitoring), online... seismic monitoring), online financial analysis, manufacturing process control, multimedia search engines, health and life sciences, and medical...classifiers using MATLAB , trained the classifiers using the MIT CBCL face database [43], and then ported them to C for LiD4E-based actor im

  11. Business Process driven solutions for innovative enterprise information systems

    OpenAIRE

    Taglino, Francesco; Lezoche, Mario

    2008-01-01

    International audience; Existing limitations and problems in the current life-cycle of software applications will encourage new development paradigms. New technological trends, aiming at responding to current needs, such as flexibility, dynamicity, scalability, will certainly drive the envisaged changes. In this paper, possible solutions for the development and maintenance of innovative enterprise information systems (IS) are outlined. In particular, it will be argued about business process d...

  12. Extending TOPS: Ontology-driven Anomaly Detection and Analysis System

    Science.gov (United States)

    Votava, P.; Nemani, R. R.; Michaelis, A.

    2010-12-01

    Terrestrial Observation and Prediction System (TOPS) is a flexible modeling software system that integrates ecosystem models with frequent satellite and surface weather observations to produce ecosystem nowcasts (assessments of current conditions) and forecasts useful in natural resources management, public health and disaster management. We have been extending the Terrestrial Observation and Prediction System (TOPS) to include a capability for automated anomaly detection and analysis of both on-line (streaming) and off-line data. In order to best capture the knowledge about data hierarchies, Earth science models and implied dependencies between anomalies and occurrences of observable events such as urbanization, deforestation, or fires, we have developed an ontology to serve as a knowledge base. We can query the knowledge base and answer questions about dataset compatibilities, similarities and dependencies so that we can, for example, automatically analyze similar datasets in order to verify a given anomaly occurrence in multiple data sources. We are further extending the system to go beyond anomaly detection towards reasoning about possible causes of anomalies that are also encoded in the knowledge base as either learned or implied knowledge. This enables us to scale up the analysis by eliminating a large number of anomalies early on during the processing by either failure to verify them from other sources, or matching them directly with other observable events without having to perform an extensive and time-consuming exploration and analysis. The knowledge is captured using OWL ontology language, where connections are defined in a schema that is later extended by including specific instances of datasets and models. The information is stored using Sesame server and is accessible through both Java API and web services using SeRQL and SPARQL query languages. Inference is provided using OWLIM component integrated with Sesame.

  13. Schedulability-Driven Communication Synthesis for Time Triggered Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    1999-01-01

    We present an approach to static priority preemptive process scheduling for the synthesis of hard real-time distributed embedded systems where communication plays an important role. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication...... delays proposing four different message scheduling policies over a time-triggered communication channel. Optimization strategies for the synthesis of communication are developed, and the four approaches to message scheduling are compared using extensive experiments....

  14. Schedulability-Driven Communication Synthesis for Time Triggered Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2004-01-01

    We present an approach to static priority preemptive process scheduling for the synthesis of hard real-time distributed embedded systems where communication plays an important role. The communication model is based on a time-triggered protocol. We have developed an analysis for the communication...... delays with four different message scheduling policies over a time-triggered communication channel. Optimization strategies for the synthesis of communication are developed, and the four approaches to message scheduling are compared using extensive experiments....

  15. Topological Frequency Conversion in Strongly Driven Quantum Systems

    Directory of Open Access Journals (Sweden)

    Ivar Martin

    2017-10-01

    Full Text Available When a physical system is subjected to a strong external multifrequency drive, its dynamics can be conveniently represented in the multidimensional Floquet lattice. The number of Floquet lattice dimensions equals the number of irrationally-related drive frequencies, and the evolution occurs in response to a built-in effective “electric” field, whose components are proportional to the corresponding drive frequencies. The mapping allows us to engineer and study temporal analogs of many real-space phenomena. Here, we focus on the specific example of a two-level system under a two-frequency drive that induces topologically nontrivial band structure in the 2D Floquet space. The observable consequence of such a construction is the quantized pumping of energy between the sources with frequencies ω_{1} and ω_{2}. When the system is initialized into a Floquet band with the Chern number C, the pumping occurs at a rate P_{12}=-P_{21}=(C/2πℏω_{1}ω_{2}, an exact counterpart of the transverse current in a conventional topological insulator.

  16. The maximum overall coefficient of performance of a solar-driven heat pump system

    Science.gov (United States)

    Yan, Zijun; Chen, Jincan

    1994-12-01

    The optimal performance of the solar-driven heat pump system consisting of a solar collector and a three-heat-source heat pump is studied, based on the linear heat-loss model of solar collectors and the general optimum relation of endoreversible three-heat-source heat pumps. The overall coefficient of performance of the system is adopted to be an objective function. The optimum operating temperature of the solar collector and the maximum overall coefficient of performance and maximum rate of heat pumping of the system are found. The results obtained here have more realistic meaning than those of classical thermodynamics for the optimal design and operation of practical solar-driven heat pump systems. Moreover, it is proven that it is not economic to use a solar-driven heat pump under certain circumstances. Finally, it is expounded that for a solar-driven heat pump system, the product of the efficiency of the solar collector and the coefficient of performance of the three-heat-source heat pump at maximum rate of heat pumping may not be used to calculate the optimal operating temperature of the solar collector and determine the optimal performance of the system.

  17. Superconducting magnet system(relating to accelerator); Chodendo magunetto shisutemu (kasokuki kanren)

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Norihito [National Laboratory for High Energy Physis, Tsukuba (Japan)

    1999-09-25

    Presentations relating to superconducting magnet system are outlined, which include the studies on C-type magnet which is used for experiments of nuclear physics at Michigan Univ., on superconducting magnet system cooled by conduction used to grow crystals in strong magnetic field at Victoria Univ., on superconducting bent solenoid system of LBNL, on magnet system relating to accelerator and on transient phenomina of superconducting magnet. There were small audience at this session, and half of the programmed presentations were cancelled. (NEDO)

  18. Optimizing a mobile robot control system using GPU acceleration

    Science.gov (United States)

    Tuck, Nat; McGuinness, Michael; Martin, Fred

    2012-01-01

    This paper describes our attempt to optimize a robot control program for the Intelligent Ground Vehicle Competition (IGVC) by running computationally intensive portions of the system on a commodity graphics processing unit (GPU). The IGVC Autonomous Challenge requires a control program that performs a number of different computationally intensive tasks ranging from computer vision to path planning. For the 2011 competition our Robot Operating System (ROS) based control system would not run comfortably on the multicore CPU on our custom robot platform. The process of profiling the ROS control program and selecting appropriate modules for porting to run on a GPU is described. A GPU-targeting compiler, Bacon, is used to speed up development and help optimize the ported modules. The impact of the ported modules on overall performance is discussed. We conclude that GPU optimization can free a significant amount of CPU resources with minimal effort for expensive user-written code, but that replacing heavily-optimized library functions is more difficult, and a much less efficient use of time.

  19. FPGA-accelerated algorithm for the regular expression matching system

    Science.gov (United States)

    Russek, P.; Wiatr, K.

    2015-01-01

    This article describes an algorithm to support a regular expressions matching system. The goal was to achieve an attractive performance system with low energy consumption. The basic idea of the algorithm comes from a concept of the Bloom filter. It starts from the extraction of static sub-strings for strings of regular expressions. The algorithm is devised to gain from its decomposition into parts which are intended to be executed by custom hardware and the central processing unit (CPU). The pipelined custom processor architecture is proposed and a software algorithm explained accordingly. The software part of the algorithm was coded in C and runs on a processor from the ARM family. The hardware architecture was described in VHDL and implemented in field programmable gate array (FPGA). The performance results and required resources of the above experiments are given. An example of target application for the presented solution is computer and network security systems. The idea was tested on nearly 100,000 body-based viruses from the ClamAV virus database. The solution is intended for the emerging technology of clusters of low-energy computing nodes.

  20. A porcine model system of BRCA1 driven breast cancer

    Directory of Open Access Journals (Sweden)

    Geoff eClark

    2015-08-01

    Full Text Available BRCA1 is a breast and ovarian tumor suppressor. Hereditary mutations in BRCA1 result in a predisposition to breast cancer, and BRCA1 expression is down-regulated in ~30% of sporadic cases. The function of BRCA1 remains poorly understood, but it appears to play an important role in DNA repair and the maintenance of genetic stability. Mouse models of BRCA1 deficiency have been developed in an attempt to understand the role of the gene in vivo. However, the subtle nature of BRCA1 function and the well-known discrepancies between human and murine breast cancer biology and genetics may limit the utility of mouse systems in defining the function of BRCA1 in cancer and validating the development of novel therapeutics for breast cancer. In contrast to mice, pig biological systems and cancer genetics appear to more closely resemble their human counterparts. To determine if BRCA1 inactivation in pig cells promotes their transformation and may serve as a model for the human disease, we developed an immortalized porcine breast cell line and stably inactivated BRCA1 using miRNA. The cell line developed characteristics of breast cancer stem cells and exhibited a transformed phenotype. These results validate the concept of using pigs as a model to study BRCA1 defects in breast cancer and establish the first porcine breast tumor cell line.

  1. Mutant PIK3CA accelerates HER2-driven transgenic mammary tumors and induces resistance to combinations of anti-HER2 therapies

    Science.gov (United States)

    Hanker, Ariella B.; Pfefferle, Adam D.; Balko, Justin M.; Kuba, María Gabriela; Young, Christian D.; Sánchez, Violeta; Sutton, Cammie R.; Cheng, Hailing; Perou, Charles M.; Cook, Rebecca S.; Arteaga, Carlos L.

    2013-01-01

    Human epidermal growth factor receptor 2 (HER2; ERBB2) amplification and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations often co-occur in breast cancer. Aberrant activation of the phosphatidylinositol 3-kinase (PI3K) pathway has been shown to correlate with a diminished response to HER2-directed therapies. We generated a mouse model of HER2-overexpressing (HER2+), PIK3CAH1047R-mutant breast cancer. Mice expressing both human HER2 and mutant PIK3CA in the mammary epithelium developed tumors with shorter latencies compared with mice expressing either oncogene alone. HER2 and mutant PIK3CA also cooperated to promote lung metastases. By microarray analysis, HER2-driven tumors clustered with luminal breast cancers, whereas mutant PIK3CA tumors were associated with claudin-low breast cancers. PIK3CA and HER2+/PIK3CA tumors expressed elevated transcripts encoding markers of epithelial-to-mesenchymal transition and stem cells. Cells from HER2+/PIK3CA tumors more efficiently formed mammospheres and lung metastases. Finally, HER2+/PIK3CA tumors were resistant to trastuzumab alone and in combination with lapatinib or pertuzumab. Both drug resistance and enhanced mammosphere formation were reversed by treatment with a PI3K inhibitor. In sum, PIK3CAH1047R accelerates HER2-mediated breast epithelial transformation and metastatic progression, alters the intrinsic phenotype of HER2-overexpressing cancers, and generates resistance to approved combinations of anti-HER2 therapies. PMID:23940356

  2. Comparative Study on Photovoltaic Pumping Systems Driven by Different Motors Optimized with Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Abdelhak Bouchakour

    2017-06-01

    Full Text Available This study investigates the performance of three different photovoltaic (PV water pumping systems driven by three types of motors, namely a separately excited DC motor (DCM, an asynchronous motor (ASM, and a permanent magnet synchronous motor (PMSM, via a DC/DC buck-boost converter coupled to a centrifugal pump. The purpose of this study is to implement a fast and robust control for this type of a nonlinear system, controlled by sliding mode (SM. This paper presents an SM control technique for controlling a DC/DC buck-boost converter to transfer the maximum power delivered by the PV generator. Each component is studied and analyzed to simulate the global system in MATLAB/SIMULINK. The three systems are then compared to determine the overall effectiveness of the proposed command. The study concludes that the ASM-driven PV system yields highly favorable results and requires less maintenance compared with other systems.

  3. Stochastic systems driven by alpha-stable noises

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Ditlevsen, P.

    1998-01-01

    It has almost become a standard in stochastic mechanics applications of stochasticdifferential equations that the driving forces are modeled as Gaussian white noises, that is, as scalar or vector Brownianmotion increments.However, this modeling may not always lead to responses that comply well...... with observed data. In particular the tailsof the observed response distributions may even for linear systems be more fat than the tails obtained for Gaussianwhite noise input. Also the excitation may show jumps that cannot be modeled by Gaussian white noise. The paper supports the possibility of using...... the larger class of so-calledalpha-stable white noises to provide a better fit. A geophysical application concerning ice age climate variations is described....

  4. Multichannel computerized control system of current pulses in LIU-30 electron accelerator

    CERN Document Server

    Gerasimov, A I; Kulgavchuk, V V; Pluzhnikov, A V

    2002-01-01

    In LIU-30 power linear pulsed induction electron accelerator (40 MeV, 10 kA, 25 ns) 288 radial lines with water insulation serve as energy accumulators and shapers of accelerating voltage pulses. The lines are charged simultaneously up to 500 kV using a system comprising 72 Arkadiev-Marx screened generators. To control parameter of synchronous pulses of charging current with up to 60 kA amplitude and 0.85 mu s duration in every of 72 charging circuits one applies a computer-aided system. Current pulse is recorded at output of every generator using the Rogowski coil signal from which via a cable line is transmitted to an analog-digital converter, is processed with 50 ns sampling and is recorded to a memory unit. Upon actuation of accelerator the signals are sequentially or selectively displayed and are compared with pulse typical shape

  5. Fault tolerant filtering and fault detection for quantum systems driven by fields in single photon states

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Qing, E-mail: qing.gao.chance@gmail.com; Dong, Daoyi, E-mail: daoyidong@gmail.com; Petersen, Ian R., E-mail: i.r.petersen@gmai.com [School of Engineering and Information Technology, University of New South Wales, Canberra, ACT 2600 (Australia); Rabitz, Herschel, E-mail: hrabitz@princeton.edu [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

    2016-06-15

    The purpose of this paper is to solve the fault tolerant filtering and fault detection problem for a class of open quantum systems driven by a continuous-mode bosonic input field in single photon states when the systems are subject to stochastic faults. Optimal estimates of both the system observables and the fault process are simultaneously calculated and characterized by a set of coupled recursive quantum stochastic differential equations.

  6. Threat driven modeling framework using petri nets for e-learning system

    OpenAIRE

    Khamparia, Aditya; Pandey, Babita

    2016-01-01

    Vulnerabilities at various levels are main cause of security risks in e-learning system. This paper presents a modified threat driven modeling framework, to identify the threats after risk assessment which requires mitigation and how to mitigate those threats. To model those threat mitigations aspects oriented stochastic petri nets are used. This paper included security metrics based on vulnerabilities present in e-learning system. The Common Vulnerability Scoring System designed to provide a...

  7. Stable charged-particle acceleration and focusing in a laser accelerator using spatial harmonics.

    Science.gov (United States)

    Naranjo, B; Valloni, A; Putterman, S; Rosenzweig, J B

    2012-10-19

    Regarding the laser-driven acceleration of charged particles in photonic systems, a central unmet challenge is the achievement of simultaneous transverse and longitudinal stability at nonultrarelativistic energies. At such energies, Earnshaw's theorem [S. Earnshaw, Trans. Cambridge Philos. Soc. 7, 97 (1842)] indicates that a synchronous accelerating wave gives a defocusing effect. We present a scheme in which particles are accelerated by interaction with a resonant spatial harmonic and are focused by strong ponderomotive interaction with nonresonant spatial harmonics. We show that this scheme exhibits net transverse focusing and longitudinal stability, and we discuss its use in a compact laser accelerator.

  8. Model Transformation for Model Driven Development of Semantic Web Enabled Multi-Agent Systems

    NARCIS (Netherlands)

    Kardas, G.; Göknil, Arda; Dikenelli, O.; Topaloglu, N.Y.; Weyns, D.; Holvoet, T.

    2007-01-01

    Model Driven Development (MDD) provides an infrastructure that simplifies Multi-agent System (MAS) development by increasing the abstraction level. In addition to defining models, transformation process for those models is also crucial in MDD. On the other hand, MAS modeling should also take care of

  9. POWER EXPENSES ON HPFP DRIVE OF DIESEL ENGINE WITH BATTERY-DRIVEN FUEL SYSTEM

    OpenAIRE

    А. Vrublevsky; A. Prohorenko; I. Pozhidaev; D. Meshkov; A. Timchenko

    2012-01-01

    The results of the research of impact of the process of fuel injection into the accumulator on the power of mechanical losses of the diesel engine are presented. The need to regulate the high pressure fuel pump for battery-driven fuel system is theoretically grounded.

  10. High-Dimensional Disorder-Driven Phenomena in Weyl Semimetals, Semiconductors and Related Systems

    CERN Document Server

    Syzranov, S V

    2016-01-01

    It is commonly believed that a non-interacting disordered electronic system can undergo only the Anderson metal-insulator transition. It has been suggested, however, that a broad class of systems can display disorder-driven transitions distinct from Anderson localisation that have manifestations in the disorder-averaged density of states, conductivity and other observables. Such transitions have received particular attention in the context of recently discovered 3D Weyl and Dirac materials but have also been predicted in cold-atom systems with long-range interactions, quantum kicked rotors and all sufficiently high-dimensional systems. Moreover, such systems exhibit unconventional behaviour of Lifshitz tails, energy-level statistics and ballistic-transport properties. Here we review recent progress and the status of results on non-Anderson disorder-driven transitions and related phenomena.

  11. Accelerating cancer systems biology research through Semantic Web technology.

    Science.gov (United States)

    Wang, Zhihui; Sagotsky, Jonathan; Taylor, Thomas; Shironoshita, Patrick; Deisboeck, Thomas S

    2013-01-01

    Cancer systems biology is an interdisciplinary, rapidly expanding research field in which collaborations are a critical means to advance the field. Yet the prevalent database technologies often isolate data rather than making it easily accessible. The Semantic Web has the potential to help facilitate web-based collaborative cancer research by presenting data in a manner that is self-descriptive, human and machine readable, and easily sharable. We have created a semantically linked online Digital Model Repository (DMR) for storing, managing, executing, annotating, and sharing computational cancer models. Within the DMR, distributed, multidisciplinary, and inter-organizational teams can collaborate on projects, without forfeiting intellectual property. This is achieved by the introduction of a new stakeholder to the collaboration workflow, the institutional licensing officer, part of the Technology Transfer Office. Furthermore, the DMR has achieved silver level compatibility with the National Cancer Institute's caBIG, so users can interact with the DMR not only through a web browser but also through a semantically annotated and secure web service. We also discuss the technology behind the DMR leveraging the Semantic Web, ontologies, and grid computing to provide secure inter-institutional collaboration on cancer modeling projects, online grid-based execution of shared models, and the collaboration workflow protecting researchers' intellectual property. Copyright © 2012 Wiley Periodicals, Inc.

  12. Piezoelectric vibration-driven locomotion systems - Exploiting resonance and bistable dynamics

    Science.gov (United States)

    Fang, Hongbin; Wang, K. W.

    2017-03-01

    While a piezoelectric-based vibration-driven system is an excellent candidate for actuating small-size crawling-type locomotion robots, it has the major drawback of limited stroke output that would severely constraint the system's locomotion performance. In this paper, to advance the state of the art, we propose two novel designs of piezoelectric vibration-driven locomotion systems. The first utilizes the resonant amplification concept, and the second explores the design of a bistable device. While these two ideas have been explored for piezoelectric actuation amplification in general, they have never been exploited for crawling-type robotic locomotion. Numerical analyses on both systems reveal that resonance and bistability can substantially increase the systems' average locomotion speed. Moreover, this research shows that with bistability, the system is able to output high average locomotion speed in a wider frequency band, possess multiple locomotion modes, and achieve fast switches among them. Through proof-of-concept prototypes, the predicted locomotion performance improvements brought by resonance and bistability are verified. Finally, the basin stability is evaluated to systematically describe the occurring probability of certain locomotion behavior of the bistable system, which would provide useful guideline to the design and control of bistable vibration-driven locomotion systems.

  13. Accelerating Medical Research using the Swift Workflow System

    Science.gov (United States)

    STEF-PRAUN, Tiberiu; CLIFFORD, Benjamin; FOSTER, Ian; HASSON, Uri; HATEGAN, Mihael; SMALL, Steven L.; WILDE, Michael; ZHAO, Yong

    2009-01-01

    Both medical research and clinical practice are starting to involve large quantities of data and to require large-scale computation, as a result of the digitization of many areas of medicine. For example, in brain research – the domain that we consider here – a single research study may require the repeated processing, using computationally demanding and complex applications, of thousands of files corresponding to hundreds of functional MRI studies. Execution efficiency demands the use of parallel or distributed computing, but few medical researchers have the time or expertise to write the necessary parallel programs. The Swift system addresses these concerns. A simple scripting language, SwiftScript, provides for the concise high-level specification of workflows that invoke various application programs on potentially large quantities of data. The Swift engine provides for the efficient execution of these workflows on sequential computers, parallel computers, and/or distributed grids that federate the computing resources of many sites. Last but not least, the Swift provenance catalog keeps track of all actions performed, addressing vital bookkeeping functions that so often cause difficulties in large computations. To illustrate the use of Swift for medical research, we describe its use for the analysis of functional MRI data as part of a research project examining the neurological mechanisms of recovery from aphasia after stroke. We show how SwiftScript is used to encode an application workflow, and present performance results that demonstrate our ability to achieve significant speedups on both a local parallel computing cluster and multiple parallel clusters at distributed sites. PMID:17476063

  14. Historical evolution of nuclear energy systems development and related activities in JAERI. Fission, fusion, accelerator utilization

    Energy Technology Data Exchange (ETDEWEB)

    Tone, Tatsuzo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    Overview of the historical evolution of nuclear energy systems development and related activities in JAERI is given in the report. This report reviews the research and development for light water reactor, fast breeder reactor, high temperature gas reactor, fusion reactor and utilization of accelerator-based neutron source. (author)

  15. Non-Destructive Damping Measurement for Wafer-Level Packaged Microelectromechanical System (MEMS) Acceleration Switches

    Science.gov (United States)

    2014-09-01

    evaluations of MEMS systems required modeling damping by evaluating displacement or oscillation using piezoelectric , electromagnetic, or electrostatic...capacitive sensing) transduction mechanisms.4,5 A previous study determined damping in oscillating cantilever tuning forks by linearizing the Reynolds...acceleration field—when switch closure occurs. Other MEMS devices use transducers like capacitive, piezoelectric , optical, and pressure to discern a

  16. Measuring acceleration and deceleration in soccer-specific movements using a Local Position Measurement (LPM) system

    NARCIS (Netherlands)

    Stevens, T.G.A.; Ruiter, de C.J.; Niel, van C.; Rhee, van de R.; Beek, P.J.; Savelsbergh, G.J.P.

    2014-01-01

    Purpose: A local position measurement (LPM) system can accurately track the distance covered and the average speed of whole-body movements. However, for the quantification of a soccer player’s workload, accelerations rather than positions or speeds are essential. The main purpose of the current

  17. A Java-based control system for the Orsay tandem accelerator

    Indian Academy of Sciences (India)

    Both the hardware and the software architecture have to guarantee flexibility, modularity and reliability. They have to accomodate modifications and extra additions during the life of the accelerator. Among several constraints and design considerations the following are worth highlighting: • The old control system and the new ...

  18. A Java-based control system for the Orsay tandem accelerator

    Indian Academy of Sciences (India)

    A new control system was designed for the tandem MP-9 at Orsay. Because of the existing devices located on high voltage platforms and the lack of space inside the accelerator, in-house electronic cards based on micro-controllers and an optical fieldbus were developed to collect data. VME processors under VxWorks, ...

  19. Status and research programs of the multinuclide accelerator mass spectrometry system at the University of Tsukuba

    Energy Technology Data Exchange (ETDEWEB)

    Sasa, Kimikazu, E-mail: ksasa@tac.tsukuba.ac.j [AMS Group, Tandem Accelerator Complex, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Takahashi, Tsutomu; Tosaki, Yuki [AMS Group, Tandem Accelerator Complex, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Matsushi, Yuki [AMS Group, Tandem Accelerator Complex, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Micro Analysis Laboratory, Tandem Accelerator, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Sueki, Keisuke; Tamari, Michiko; Amano, Takahiro; Oki, Toshiyuki; Mihara, Shozo; Yamato, Yoshihiro; Nagashima, Yasuo [AMS Group, Tandem Accelerator Complex, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Bessho, Kotaro; Kinoshita, Norikazu; Matsumura, Hiroshi [Radiation Science Center, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2010-04-15

    We present the current status and research programs of a multinuclide accelerator mass spectrometry (AMS) system on the 12UD Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system), Japan. A maximum terminal voltage of 12 MV is available for the AMS system. The Tsukuba AMS system can measure environmental levels of long-lived radioisotopes of {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 129}I by employing a molecular pilot beam. Recently, enhancements in AMS techniques and equipment, including sample preparation, the ion source and the data acquisition system, have improved the performance of {sup 36}Cl-AMS. The standard deviation of fluctuations is typically +-2%, and the machine background level for the {sup 36}Cl/Cl ratio is lower than 1 x 10{sup -15} with a halite sample. We have measured over 500 samples in 1 year, including samples for earth and environmental sciences and nuclear safety research.

  20. First Assessment of Reliability Data for the LHC Accelerator and Detector Cryogenic System Components

    CERN Document Server

    Perinic, G; Alonso-Canella, I; Balle, C; Barth, K; Bel, J F; Benda, V; Bremer, J; Brodzinski, K; Casas-Cubillos, J; Cuccuru, G; Cugnet, M; Delikaris, D; Delruelle, N; Dufay-Chanat, L; Fabre, C; Ferlin, G; Fluder, C; Gavard, E; Girardot, R; Haug, F; Herblin, L; Junker, S; Klabi , T; Knoops, S; Lamboy, J P; Legrand, D; Metselaar, J; Park, A; Perin, A; Pezzetti, M; Penacoba-Fernandez, G; Pirotte, O; Rogez, E; Suraci, A; Stewart, L; Tavian, L J; Tovar-Gonzalez, A; Van Weelderen, R; Vauthier, N; Vullierme, B; Wagner, U

    2012-01-01

    The Large Hadron Collider (LHC) cryogenic system comprises eight independent refrigeration and distribution systems that supply the eight 3.3 km long accelerator sectors with cryogenic refrigeration power as well as four refrigeration systems for the needs of the detectors ATLAS and CMS. In order to ensure the highest possible reliability of the installations, it is important to apply a reliability centred approach for the maintenance. Even though large scale cryogenic refrigeration exists since the mid 20th century, very little third party reliability data is available today. CERN has started to collect data with its computer aided maintenance management system (CAMMS) in 2009, when the accelerator has gone into normal operation. This paper presents the reliability observations from the operation and the maintenance side, as well as statistical data collected by the means of the CAMMS system.