WorldWideScience

Sample records for low-energy continuous reactor-separator

  1. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Prasad, R; Yadav, R S [Aligarh Muslim Univ. (India). Dept. of Physics; Naqvi, T H [Z.H. Engineering Coll., Aligarh (India); Ahmed, Rais [National Council of Educational Research and Training, New Delhi (India)

    1975-12-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described.

  2. Instrumentation for continuous monitoring of low energy cosmic ray intensity

    International Nuclear Information System (INIS)

    Kumar, S.; Prasad, R.; Yadav, R.S.; Ahmed, Rais

    1975-01-01

    A high counting rate neutron monitor developed at Aligarh for continuous monitoring of low energy nucleonic component of cosmic rays is described. Transistorized electronic circuits used are described. (author)

  3. Bioeffects of low-energy continuous ultrasound on isolated sarcoma 180 cells.

    Science.gov (United States)

    Wang, Xiaobing; Liu, Quanhong; Wang, Zhezhi; Wang, Pan; Hao, Qiao; Li, Chendi

    2009-01-01

    The aim of this study was to investigate the mechanism underlying bioeffects of low-intensity continuous ultrasound on isolated sarcoma 180 (S180) cells and cellular responses to these effects. After sonication, several structural and functional parameters were examined to elucidate ultrasound-induced cell damage. Instant disruption of the cell membrane might be caused by acoustic cavitation, producing mechanical and chemical effects that acted simultaneously on S180 cells; this could be reflected by immediate (morphological) changes such as membrane permeability, membrane fluidity, lipid peroxidation and the generation of hydroxyl radicals in culture medium. Our results of the delayed effects also indicated S180 cells were sensitive to ultrasound-induced apoptosis, and the rate of apoptosis rose gradually with a prolonged incubation time. The presence of apoptotic cells was identified by a distinct morphological form characterized by membrane blebbing, cell shrinkage, chromatin condensation and DNA fragmentation. Moreover, delayed cytotoxicity was accompanied by an increase in intracellular reactive oxygen species (ROS) and a decrease in the mitochondrial membrane potential, and the two events presented obviously a negative correlation. ROS secondarily generated from damaged mitochondria may play a role in the induction of apoptosis. Copyright 2009 S. Karger AG, Basel.

  4. Low energy elastic scattering of positrons by CO: An application of continued fractions and Schwinger variational iterative methods

    Energy Technology Data Exchange (ETDEWEB)

    Arretche, F. [Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, Santa Catarina (Brazil)], E-mail: farretche@hotmail.com; Mazon, K.T.; Michelin, S.E. [Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, Santa Catarina (Brazil); Fujimoto, M.M. [Departamento de Fisica, Universidade Federal do Parana, 81531-990, Curitiba, Parana (Brazil); Iga, I.; Lee, M.-T. [Departamento de Quimica, Universidade Federal de Sao Carlos, 13565-905, Sao Paulo (Brazil)

    2008-02-15

    Iterative Schwinger variational methods and the method of continued fractions, widely used for electron-molecule scattering, are applied for the first time to investigate positron-molecule interactions. Specifically, integral and differential cross sections for elastic positron scattering by CO in the (0.5-20) eV energy range are calculated and reported. In our calculation, a static plus correlation-polarization potential is used to represent the collisional dynamics. Our calculated results are in general agreement with the theoretical and experimental data available in the literature.

  5. Annual Continuation And Progress Report For Low-Energy Nuclear Physics Research At Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, N. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wu, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-27

    Ba where the octupole deformation is evident from the measured B(E3; 3-→0+) strengths that significantly greater than the theoretical predictions. We anticipate that CHICO2 will continue to be a viable charged-­particle detector for the research need of the low-­energy nuclear physics community.

  6. Low energy supersymmetry phenomenology

    International Nuclear Information System (INIS)

    Baer, H.; Chen, C.H.; Gunion, J.; Kamon, T.; Lopez, J.L.; Kao, C.

    1995-04-01

    The authors summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, they evaluate the capabilities of various e + e - , p bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, they discuss capabilities of future facilities to disentangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. The authors then comment upon the complementarity of proposed hadron and e + e - machines for a comprehensive study of low energy supersymmetry

  7. Low energy supersymmetry phenomenology

    CERN Document Server

    Baer, H.; Chen, C.H.; Eberl, H.; Feng, J.L.; Fujii, K.; Gunion, John F.; Kamon, T.; Kao, C.; Lopez, J.L.; Majerotto, W.; McIntyre, P.; Munroe, Ray B.; Murayama, H.; Paige, F.; Porod, W.; Sender, J.; Sopczak, A.; Tata, X.; Tsukamoto, T.; White, J.

    1996-01-01

    We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various e^+e^-, p\\bar p and pp colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and e^+e^- machines for a comprehensive study of low energy supersymmetry.

  8. Low-energy QCD

    International Nuclear Information System (INIS)

    Ecker, G.

    1995-11-01

    After a brief introduction to chiral perturbation theory, the effective field theory of the standard model at low energies, two recent applications are reviewed: elastic pion-pion scattering to two-loop accuracy and the complete renormalized pion-nucleon Lagrangian to O(P 3 ) in the chiral expansion. (author)

  9. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  10. Low Energy Conference 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    11 of the 19 presentations have been indexed for the database. The following national organisations jointly organised the Low-energy Conference 2009: The Norwegian Society for the Conservation of Nature, the Norwegian Society of Engineers and Technologists, Norwegian Technology, the Federation of Norwegian Industries and the Low-Energy Program. Energy efficiency is often given little attention in the ongoing debates concerning different initiatives in order to reduce greenhouse emissions. The aim of the conference was to set energy efficiency on the agenda as an important environmental instrument. Both the Intergovernmental Panel on Climate Change - IPCC and the International Energy Agency - IEA regard energy efficiency as one of the fastest and most effective ways of reducing greenhouse emissions. Despite of this little is done. Many countries are ahead of Norway - why are we lagging behind? The Low-Energy conference has a broad approach: Nigel Jollands from the International Energy Agency -IEA puts energy efficiency in a global perspective. Soeren Rise from Teqniq in Denmark informs about the Danes' energy saving agreement, which appears to have been a success. The conference increased the competencies on concrete energy efficiency solutions, how to speed up the marketing of energy-friendly buildings and technologies, possibilities through industry and the impact of EU-directives and other instruments in order to trigger the potential. The conference closed with a discussion panel of leading energy politicians. The conference contributed to raise the debate in advance of the General election in Norway and the climate negotiations in Copenhagen during the autumn 2009. (EW)

  11. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    For a class of negative slowly decaying potentials, including with , we study the quantum mechanical scattering theory in the low-energy regime. Using modifiers of the Isozaki--Kitada type we show that scattering theory is well behaved on the {\\it whole} continuous spectrum of the Hamiltonian......, including the energy . We show that the --matrices are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use appropriate weighted spaces. These results are used...... from positive energies to the limiting energy . This change corresponds to the behaviour of the classical orbits. Under stronger conditions we extract the leading term of the asymptotics of the kernel of at its singularities; this leading term defines a Fourier integral operator in the sense...

  12. Quantum scattering at low energies

    DEFF Research Database (Denmark)

    Derezinski, Jan; Skibsted, Erik

    2009-01-01

    For a class of negative slowly decaying potentials, including V(x):=−γ|x|−μ with 0quantum mechanical scattering theory in the low-energy regime. Using appropriate modifiers of the Isozaki–Kitada type we show that scattering theory is well behaved on the whole continuous spectrum...... of the Hamiltonian, including the energy 0. We show that the modified scattering matrices S(λ) are well-defined and strongly continuous down to the zero energy threshold. Similarly, we prove that the modified wave matrices and generalized eigenfunctions are norm continuous down to the zero energy if we use...... of the kernel of S(λ) experiences an abrupt change from passing from positive energies λ to the limiting energy λ=0 . This change corresponds to the behaviour of the classical orbits. Under stronger conditions one can extract the leading term of the asymptotics of the kernel of S(λ) at its singularities....

  13. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  14. Extra Low ENergy Antiproton

    CERN Multimedia

    To produce dense antiproton beams at very low energies (110 keV), it has been proposed to install a small decelerator ring between the existing AD ring and the experimental area. Phase-space blowup during deceleration is compensated by electron cooling such that the final emittances are comparable to the 5MeV beam presently delivered by the AD. An immediate consequence is a significant increase in the number of trapped antiprotons at the experiments as outlined in the proposal CERN/SPSC-2009-026; SPCS-P-338. This report describes the machine parameters and layout of the proposal ELENA (Extra Low ENergy Antiproton)ring also gives an approximate estimate of cost and manpower needs. Since the initial estimate, published in 2007 (CERN-AB-2007-079), the ELENA design has evolved considerably. This is due to a new location in the AD hall to acommodate for the possibility of another experimental zone, as suggested by the SPCS, and also due to improvements in the ring optics and layout. The cost estimate that is prese...

  15. Inside bluetooth low energy

    CERN Document Server

    Gupta, Naresh

    2013-01-01

    Bluetooth Low Energy (LE) is one of the latest enhancement to Bluetooth technology and, as the name suggests, it is aimed at ultra low power devices, such as heart rate monitors, thermometers, and sensors. Due to very low power consumption, devices compliant with this standard can operate for several years on coin cell batteries without the need for recharging. This cutting-edge book helps you understand the whats , whys , and hows of Bluetooth LE. It includes a broad view of the technology, identifies the various building blocks, and explains how they come together. You also find discussions on Bluetooth basics, providing the background information needed to master Bluetooth LE.The book explains the architecture of Bluetooth LE stack and the functionality provided by each of the layers. You find expert guidance in setting up your own system in a quick and efficient manner with inexpensive, easily available hardware and just a couple of PCs running Linux. This unique volume features two chapters that are dedi...

  16. Solar low energy dwellings

    International Nuclear Information System (INIS)

    Hestnes, Anne Grete

    2000-01-01

    By now, a lot has been learnt about how to reduce energy use in dwellings using solar and low energy technologies, and many good examples can be found throughout Europe. Still, they are not quite the common feature we would expect them to be, i.e. they have not really penetrated the market. The reason for this is in part a result of the fact that the designers and developers of these buildings have not looked at what the market wants and needs, but rather at how to use a set of given technologies. The buildings are the result of a technology push rather than a market pull and have therefore, often, been detached or semidetached dwellings with different solar technologies added on in less than optimal ways. In order to increase market penetration, it is time to look at the market trends and relate to these. Fortunately, quite a few European architects have realized this and have started designing somewhat different residential buildings. The paper focuses on examples of the new trends in solar residential architecture and by that, hopefully, it shows that we are on the right track. (au)

  17. Very low energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

  18. Low energy analysis techniques for CUORE

    Energy Technology Data Exchange (ETDEWEB)

    Alduino, C.; Avignone, F.T.; Chott, N.; Creswick, R.J.; Rosenfeld, C.; Wilson, J. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); Alfonso, K.; Huang, H.Z.; Sakai, M.; Schmidt, J. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Artusa, D.R.; Rusconi, C. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States); INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Azzolini, O.; Camacho, A.; Keppel, G.; Palmieri, V.; Pira, C. [INFN-Laboratori Nazionali di Legnaro, Padua (Italy); Bari, G.; Deninno, M.M. [INFN-Sezione di Bologna, Bologna (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); Bellini, F.; Cosmelli, C.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Benato, G.; Singh, V. [University of California, Department of Physics, Berkeley, CA (United States); Bersani, A.; Caminata, A. [INFN-Sezione di Genova, Genoa (Italy); Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Chiesa, D.; Clemenza, M.; Faverzani, M.; Fiorini, E.; Gironi, L.; Gotti, C.; Maino, M.; Nastasi, M.; Nucciotti, A.; Pavan, M.; Pozzi, S.; Sisti, M.; Terranova, F.; Zanotti, L. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN-Sezione di Milano Bicocca, Milan (Italy); Branca, A.; Taffarello, L. [INFN-Sezione di Padova, Padua (Italy); Bucci, C.; Cappelli, L.; D' Addabbo, A.; Gorla, P.; Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Canonica, L. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Massachusetts Institute of Technology, Cambridge, MA (United States); Cao, X.G.; Fang, D.Q.; Ma, Y.G.; Wang, H.W.; Zhang, G.Q. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai (China); Cardani, L.; Casali, N.; Dafinei, I.; Morganti, S.; Mosteiro, P.J.; Tomei, C.; Vignati, M. [INFN-Sezione di Roma, Rome (Italy); Copello, S.; Di Domizio, S.; Marini, L.; Pallavicini, M. [INFN-Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Cremonesi, O.; Ferri, E.; Giachero, A.; Pessina, G.; Previtali, E. [INFN-Sezione di Milano Bicocca, Milan (Italy); Cushman, J.S.; Davis, C.J.; Heeger, K.M.; Lim, K.E.; Maruyama, R.H. [Yale University, Department of Physics, New Haven, CT (United States); D' Aguanno, D.; Pagliarone, C.E. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita degli Studi di Cassino e del Lazio Meridionale, Dipartimento di Ingegneria Civile e Meccanica, Cassino (Italy); Dell' Oro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); INFN-Gran Sasso Science Institute, L' Aquila (Italy); Di Vacri, M.L.; Santone, D. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, L' Aquila (Italy); Drobizhev, A.; Hennings-Yeomans, R.; Kolomensky, Yu.G.; Wagaarachchi, S.L. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Franceschi, M.A.; Ligi, C.; Napolitano, T. [INFN-Laboratori Nazionali di Frascati, Rome (Italy); Freedman, S.J. [University of California, Department of Physics, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Fujikawa, B.K.; Mei, Y.; Schmidt, B.; Smith, A.R.; Welliver, B. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Giuliani, A.; Novati, V. [Universite Paris-Saclay, CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Orsay (France); Gladstone, L.; Leder, A.; Ouellet, J.L.; Winslow, L.A. [Massachusetts Institute of Technology, Cambridge, MA (United States); Gutierrez, T.D. [California Polytechnic State University, Physics Department, San Luis Obispo, CA (United States); Haller, E.E. [Lawrence Berkeley National Laboratory, Materials Science Division, Berkeley, CA (United States); University of California, Department of Materials Science and Engineering, Berkeley, CA (United States); Han, K. [Shanghai Jiao Tong University, Department of Physics and Astronomy, Shanghai (China); Hansen, E. [University of California, Department of Physics and Astronomy, Los Angeles, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Kadel, R. [Lawrence Berkeley National Laboratory, Physics Division, Berkeley, CA (United States); Martinez, M. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN-Sezione di Roma, Rome (Italy); Universidad de Zaragoza, Laboratorio de Fisica Nuclear y Astroparticulas, Saragossa (Spain); Moggi, N.; Zucchelli, S. [INFN-Sezione di Bologna, Bologna (Italy); Universita di Bologna - Alma Mater Studiorum, Dipartimento di Fisica e Astronomia, Bologna (IT); Nones, C. [CEA/Saclay, Service de Physique des Particules, Gif-sur-Yvette (FR); Norman, E.B.; Wang, B.S. [Lawrence Livermore National Laboratory, Livermore, CA (US); University of California, Department of Nuclear Engineering, Berkeley, CA (US); O' Donnell, T. [Virginia Polytechnic Institute and State University, Center for Neutrino Physics, Blacksburg, VA (US); Sangiorgio, S.; Scielzo, N.D. [Lawrence Livermore National Laboratory, Livermore, CA (US); Wise, T. [Yale University, Department of Physics, New Haven, CT (US); University of Wisconsin, Department of Physics, Madison, WI (US); Woodcraft, A. [University of Edinburgh, SUPA, Institute for Astronomy, Edinburgh (GB); Zimmermann, S. [Lawrence Berkeley National Laboratory, Engineering Division, Berkeley, CA (US)

    2017-12-15

    CUORE is a tonne-scale cryogenic detector operating at the Laboratori Nazionali del Gran Sasso (LNGS) that uses tellurium dioxide bolometers to search for neutrinoless double-beta decay of {sup 130}Te. CUORE is also suitable to search for low energy rare events such as solar axions or WIMP scattering, thanks to its ultra-low background and large target mass. However, to conduct such sensitive searches requires improving the energy threshold to 10 keV. In this paper, we describe the analysis techniques developed for the low energy analysis of CUORE-like detectors, using the data acquired from November 2013 to March 2015 by CUORE-0, a single-tower prototype designed to validate the assembly procedure and new cleaning techniques of CUORE. We explain the energy threshold optimization, continuous monitoring of the trigger efficiency, data and event selection, and energy calibration at low energies in detail. We also present the low energy background spectrum of CUORE-0 below 60 keV. Finally, we report the sensitivity of CUORE to WIMP annual modulation using the CUORE-0 energy threshold and background, as well as an estimate of the uncertainty on the nuclear quenching factor from nuclear recoils in CUORE-0. (orig.)

  19. Effect of ultrasound on flotation kinetics in the reactor-separator

    International Nuclear Information System (INIS)

    Filippov, L O; Matinin, A S; Samiguin, V D; Filippova, I V

    2013-01-01

    Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

  20. Effect of ultrasound on flotation kinetics in the reactor-separator

    Science.gov (United States)

    Filippov, L. O.; Matinin, A. S.; Samiguin, V. D.; Filippova, I. V.

    2013-03-01

    Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

  1. A reactor/separator device for use in automated solid phase immunoassay

    International Nuclear Information System (INIS)

    Farina, P.R.; Ordonez, K.P.; Siewers, I.J.

    1979-01-01

    A reactor/separator device is described for use in automated solid phase immunoassay, including radioimmunoassays. The device is a column fitted at the bottom portion with a water impermeable disc which can hold, for example, immunoabsorbents, immobilized antisera or ion exchange resins. When the contents of the column supported by the disc are brought into contact with an aqueous phase containing reagents or reactants, a chemical reaction is initiated. After the reaction, centrifugally applied pressure forces the aqueous phase through the filter disc making it water permeable and separating a desired component for subsequent analysis. The reactor/separator device of the present invention permits kinetic solid phase assays (non-equilibrium conditions) to be carried out which would be difficult to perform by other conventional methods. (author)

  2. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    2012-10-05

    Oct 5, 2012 ... Abstract. Low-energy solar neutrino detection plays a fundamental role in ... the experimental point of view, there are multiple ways to shed light among the different .... compared to the two metallicity expectations [16]. ..... from the Earth; solar neutrinos; indirect dark matter searches) and GeV physics (pro-.

  3. Low-energy nuclear physics

    International Nuclear Information System (INIS)

    1985-01-01

    The 1985 annual report of the Schuster Laboratory, Manchester University, England, on low-energy nuclear physics, is presented. The report includes experiments involving: high spin states, nuclei far from stability, reactions and fission, spectroscopy and related subjects. Technical developments are also described. (U.K.)

  4. Low-energy neutrino measurements

    Indian Academy of Sciences (India)

    Low-energy solar neutrino detection plays a fundamental role in understanding both solar astrophysics and particle physics. After introducing the open questions on both fields, we review here the major results of the last two years and expectations for the near future from Borexino, Super-Kamiokande, SNO and KamLAND ...

  5. Low Energy Neutrino Cross Sections

    International Nuclear Information System (INIS)

    Zeller, G.P.

    2004-01-01

    Present atmospheric and accelerator based neutrino oscillation experiments operate at low neutrino energies (Ev ∼ 1 GeV) to access the relevant regions of oscillation parameter space. As such, they require precise knowledge of the cross sections for neutrino-nucleon interactions in the sub-to-few GeV range. At these energies, neutrinos predominantly interact via quasi-elastic (QE) or single pion production processes, which historically have not been as well studied as the deep inelastic scattering reactions that dominate at higher energies.Data on low energy neutrino cross sections come mainly from bubble chamber, spark chamber, and emulsion experiments that collected their data decades ago. Despite relatively poor statistics and large neutrino flux uncertainties, these measurements provide an important and necessary constraint on Monte Carlo models in present use. The following sections discuss the current status of QE, resonant single pion, coherent pion, and single kaon production cross section measurements at low energy

  6. A low energy solar town

    Energy Technology Data Exchange (ETDEWEB)

    Svendsen, Svend; Balocco, Carla

    1998-12-31

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m{sup 2}/year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs.

  7. A low energy solar town

    International Nuclear Information System (INIS)

    Svendsen, Svend; Balocco, Carla

    1998-01-01

    The use of solar energy at large scale is necessary to support the energy savings and a more efficient energy use, like besides the quality of the ambient and the quality of the available energy sources. The solar heating systems with seasonal storage can be combined with heat from refuse incineration plants and other renewable heat sources. These systems combined with district heating are an example of the sustainable energy planning and the reduction of the environmental stress. Strategies for sustainability in the settlements can be defined by and energy model to planning that individuates development and economic and financial supports to. The aim of the work concerns the development of a small sun city with no use of fossil fuels. The new low energy solar town is an idealised urban an energy system. The studied settlement regards one thousand new low-energy houses supplied by a district heating with a central solar heating system with seasonal heat storage. The heating and ventilation demand in the studied low energy buildings are less than 40 kWh/m 2 /year, the electricity demand is less than 2000 kWh per house year. The result of the work is an useful tool to the energy planning of the urban areas and it is also a necessary support to the political and energetic decisions. (EG) 58 refs

  8. Low energy bar pp physics

    International Nuclear Information System (INIS)

    Amsler, C.; Crowe, K.

    1989-02-01

    A detailed investigation of proton-antiproton interactions at low energy has become feasible with the commissioning of the LEAR facility in 1983. We shall shortly review the status of bar pp annihilation at rest and the physics motivations for second generation experiments with the Crystal Barrel detector. This type of detector would be adequate for the study of both Kp and bar pp interactions on an extracted beam of the KAON Factory. We shall conclude with a few remarks on the physics opportunities with bar p's at the KAON Factory which, in our opinion, will not be covered by the present LEAR facility. 11 refs., 10 figs., 2 tabs

  9. The low-energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Low-energy geothermal resources are characterized by temperatures ranging from 30 to 100 C. The principal worldwide applications are: towns and greenhouses heating, spa bathing, agriculture products drying, etc.. Sources depth ranges from 1500 to 2500 m in porous and permeable formations (sandstones, sands, conglomerates, limestones..) carrying aquifers. The worldwide installed power was of about 11500 MWth in 1990, with an annual production of about 36000 GWh (about 1% of worldwide energy consumption). The annual production rate is estimated to 10% and would represent a 30000 and 80000 MWth power in 2000 and 2010, respectively. In France, low-energy geothermal resources are encountered principally in Mesozoic sediments of the Parisian and Aquitanian basins. French geothermics has developed during the last 30 years and principally between 1980 and 1985 after the second petroleum crack. After 1985, the decay of fossil fuel costs and the development of corrosion problems in the geothermal wells have led to the abandonment of the less productive fields and to the study of technical solutions to solve the corrosion problems. (J.S.). 1 fig., 5 photos

  10. Analysis of low energy beta-emitters

    International Nuclear Information System (INIS)

    Murphy, D.L.

    1979-10-01

    A survey was made of the instruments used for the determination of low energy beta radioactivity. Techniques commonly used are gas flow proportional counting, liquid scintillation counting, solid scintillation counting, and internal ionization chamber counting, solid state detector counting, and radiochemical separation followed by counting using one of the preceeding techniques. The first four techniques were examined and compared with each other. The sensitivities of the techniques were compared on the basis of the detection limits quoted for instruments described in the technical and reviewed literature. The detection limits were then related to the occupational and public individual maximum levels for air and water. Attention is focused primarily on the continuous monitoring of air for 3 H and 85 Kr, a medium energy β-emitter. It is clear that several continuous air monitoring instruments are readily available for measuring low energy β concentrations, even in presence of certain other activity, at occupational levels. However, these instruments do not typically have sensitivities comparable to the public individual levels. Moreover, their capabilities for giving results in real time and for differentiating among the radionuclides actually present is limited

  11. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

    and with as little energy consumption as 41.1 kWh/m2/year including heating and all building services with no use of renewable energy such as PVcells or solar heating. One of the key means of reaching the objectives was to implement mechanical ventilation with low pressure loss and therefore low energy consumption....... The project consists of two buildings, building one is 6 stories high, and building two is 4 stories high. The buildings have a gross area of 50,500 m2 including underground parking. The ventilation and indoor climate concept was to use mechanical ventilation together with mechanical cooling and fanassisted......, with an average of 1.1 kJ/m3. The yearly mean SFP based on estimated runtime is approx. 0.8 kJ/m3. The case shows the unlocked potential that lies within mechanical ventilation for nearzero energy consuming buildings....

  12. Theory of low energy collisions

    International Nuclear Information System (INIS)

    Sparenberg, J.M.

    2007-01-01

    The basic notions of low-energy quantum scattering theory are introduced (cross sections, phase shifts, resonances,... ), in particular for positively-charged particles, in view of nuclear physics applications. An introduction to the reaction-matrix (or R-matrix) method is then proposed, as a tool to both solve the Schroedinger equation describing collisions and fit experimental data phenomenologically. Most results are established without proof but with a particular emphasis on their intuitive understanding and their possible analogs in classical mechanics. Several choices are made consequently: (i) the text starts with a detailed reminder of classical scattering theory, (ii) the concepts are first introduced in ideal theoretical cases before going to the more complicated formalism allowing the description of realistic experimental situations, (iii) a single example is used throughout nearly the whole text, (iv) all concepts are established for the elastic scattering of spinless particles, with only a brief mention of their multichannel generalization at the end of the text. (author)

  13. Intense low energy positron beams

    International Nuclear Information System (INIS)

    Lynn, K.G.; Jacobsen, F.M.

    1993-01-01

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e + beams exist producing of the order of 10 8 - 10 9 e + /sec. Several laboratories are aiming at high intensity, high brightness e + beams with intensities greater than 10 9 e + /sec and current densities of the order of 10 13 - 10 14 e + sec - 1 cm -2 . Intense e + beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B + moderators or by increasing the available activity of B + particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e + collisions with atoms and molecules. Within solid state physics high intensity, high brightness e + beams are in demand in areas such as the re-emission e + microscope, two dimensional angular correlation of annihilation radiation, low energy e + diffraction and other fields. Intense e + beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies

  14. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Hoshi, Masaharu; Antoku, Shigetoshi; Russell, W.J.; Miller, R.C.; Nakamura, Nori; Mizuno, Masayoshi; Nishio, Shoji.

    1987-05-01

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60 Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60 Co. The RBE of 200 kVp X rays relative to 60 Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  15. Low energy physics from superstrings

    International Nuclear Information System (INIS)

    Segre, G.C.

    1987-01-01

    The developments of the past year have resulted in growing interest in the theory of superstrings, a subject which is on the one hand extraordinarily exciting in the promise it holds for solutions of many of the outstanding problems of particle physics and on the other hand rather forbidding in the amount of new knowledge which needs to be acquired by the average theorist to understand the papers that are now being published on the recent developments. In a sense the term low energy superstrings is misleading: the work of the past fifteen years in string theory, culminating in last summer's stunning developments by Green and Schwartz have led theorists to believe a finite, consistent superstring theory can be formulated. An enormous amount of work is going on in this subject, the premise that an effective field theory in ten space-time dimensions can be obtained from the superstring theory is the start of the lectures. The lectures will cover this later stage, namely how does one proceed from the effective ten dimensional theory to an effective four dimensional theory, describing the world as we see it. 87 references, 2 tables

  16. Towards Low Energy Atrial Defibrillation

    Directory of Open Access Journals (Sweden)

    Philip Walsh

    2015-09-01

    . Efficient transcutaneous power transfer and sensing of ICI during cardioversion are evidenced as key to the advancement of low-energy atrial defibrillation.

  17. Low-energy Electro-weak Reactions

    International Nuclear Information System (INIS)

    Gazit, Doron

    2012-01-01

    Chiral effective field theory (EFT) provides a systematic and controlled approach to low-energy nuclear physics. Here, we use chiral EFT to calculate low-energy weak Gamow-Teller transitions. We put special emphasis on the role of two-body (2b) weak currents within the nucleus and discuss their applications in predicting physical observables.

  18. Theorems of low energy in Compton scattering

    International Nuclear Information System (INIS)

    Chahine, J.

    1984-01-01

    We have obtained the low energy theorems in Compton scattering to third and fouth order in the frequency of the incident photon. Next we calculated the polarized cross section to third order and the unpolarized to fourth order in terms of partial amplitudes not covered by the low energy theorems, what will permit the experimental determination of these partial amplitudes. (Author) [pt

  19. Solar-assisted low energy dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, T V

    1980-02-01

    The Zero Energy House Group was formed as a subproject of the CCMS Solar Energy Pilot Study in 1974 by seven participating countries experimenting with solar-assisted low-energy dwellings for temperate and northern European climatic conditions. A Zero Energy House is one in which solar energy is used to meet the reduced energy needs of buildings incorporating various thermal energy conservation features. This final report of the Zero Energy House Group includes brief descriptions of 13 major low-energy dwellings in the participating CCMS countries. An overall assessment of the state-of-the-art in solar-assisted low-energy dwellings is also included.

  20. Design and construction of a 7,500 liter immobilized cell reactor-separator for ethanol production from whey

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.

    1992-12-31

    A 7,500 liter reactor/separator has been constructed for the production of ethanol from concentrated whey permeate. This unit is sited in Hopkinton IA, across the street from a whey generating cheese plant A two phase construction project consisting of (1) building and testing a reactor/separator with a solvent absorber in a single unified housing, and (2) building and testing an extractive distillation/product stripper for the recovery of anhydrous ethanol is under way. The design capacity of this unit is 250,000 gal/yr of anhydrous product. Design and construction details of the reactor/absorber separator are given, and design parameters for the extractive distillation system are described.

  1. Fundamental physics with low-energy neutrons

    International Nuclear Information System (INIS)

    Barrón-Palos, Libertad

    2016-01-01

    Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing. (paper)

  2. Pion nucleon interaction at low energy

    International Nuclear Information System (INIS)

    Banerjee, M.K.

    1979-03-01

    A theory of the πN interaction at low energy is described. An analogy is made with an unusual approach to potential scattering theory. Phase shifts, cross sections, and scattering amplitudes and lengths are calculated. 28 references

  3. Current status of low energy EB machine

    International Nuclear Information System (INIS)

    Toshiro Nishikimi; Shuichi Taniguchi; Kenichi Mizusawa

    1999-01-01

    Electron beam processing systems have been in use in a variety of applications such as curing of paints and printing inks, crosslinking of PE products, treating of rubber tire and so on. Low energy electron processing systems have become popular as self-shielded machines, which are compact and easy to use and do not require special facility as an irradiation room. This manuscript introduces the status of low energy EB (electron beam) machine through Nissin's products current

  4. Enhancement Mechanisms of Low Energy Nuclear Reactions

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2005-01-01

    The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy o...

  5. Exploring the Hidden Sector @ Low Energies

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Over the years we have accumulated a large number of indications for physics beyond the standard model. This new physics is often sought-after at high masses and energies. Here collider experiments can bring decisive insights. However, over recent years it has become increasingly clear that new physics can also appear at low energy, but extremely weak coupling. Experiments and observations at this `low energy frontier' therefore provide a powerful tool to gain insight into fundamental physics, which is complementary to accelerators.

  6. An online low energy gaseous ion source

    International Nuclear Information System (INIS)

    Jin Shuoxue; Guo Liping; Peng Guoliang; Zhang Jiaolong; Yang Zheng; Li Ming; Liu Chuansheng; Ju Xin; Liu Shi

    2010-01-01

    The accumulation of helium and/or hydrogen in nuclear materials may cause performance deterioration of the materials. In order to provide a unique tool to investigate the He-and/or H-caused problems, such as interaction of helium with hydrogen and defects, formation of gas bubbles and its evolution, and the related effects, we designed a low energy (≤ 20 keV) cold cathode Penning ion source, which will be interfaced to a 200 kV transmission electron microscope (TEM), for monitoring continuously the evolution of micro-structure during the He + or H + ion implantation. Studies on discharge voltage-current characteristics of the ion source, and extraction and focusing of the ion beam were performed. The ion source works stably with 15-60 mA of the discharge current.Under the gas pressure of 5 x 10 -3 Pa and 1.5 x 10 -2 Pa, the discharge voltage are about 380 V and 320 V, respectively. The extracted ion current under lower gas pressure is greater than that under higher gas pressure, and it increases with the discharge current and extraction voltage. The ion lens consisting of three equal-diameter metal cylinder focus the ion beam effectively, so that the beam density at the 150 cm away from the lens exit increases by a over one order of magnitude. For ion beams of around 10 keV, the measured beam density is about 200 nA · cm -2 , which is applicable for ion implantation and in situ TEM observation for many kinds of nuclear materials. (authors)

  7. Surface sterilization by low energy electron beams

    International Nuclear Information System (INIS)

    Sekiguchi, Masayuki; Tabei, Masae

    1989-01-01

    The germicidal effectiveness of low energy electron beams (175 KV) against bacterial cells was investigated. The dry spores of Bacillus pumilus ATCC 27142 and Bacillus globigii ATCC 9372 inoculated on carrier materials and irradiated by gamma rays showed the exponential type of survival curves whereas they showed sigmoidal ones when exposed to low energy electron beams. When similarly irradiated, the wet spores inoculated on membrane filter showed the same survival curves as the dry spores inoculated on carrier materials. The wet vegetative cells of Escherichia coli ATCC 25922 showed exponential curves when exposed to gamma and electron beam irradiation. Low energy electron beams in air showed little differences from nitrogen stream in their germicidal effectiveness against dry spores of B. pumilus. The D values of B. pumilus spores inoculated on metal plates decreased as the amounts of backscattering electrons from the plates increased. There was adequate correlation between the D value (linear region of survival curve), average D value (6D/6) and 1% survival dose and backscattering factor. Depth dose profile and backscatterig dose of low energy electron beams were measured by radiochromic dye film dosimeter (RCD). These figures were not always in accord with the observed germicidal effectiveness against B. pumilus spores because of varying thickness of RCD and spores inoculated on carrier material. The dry spores were very thin and this thinness was useful in evaluating the behavior of low energy electrons. (author)

  8. Low energy plasma observations at synchronous orbit

    International Nuclear Information System (INIS)

    Reasoner, D.L.; Lennartsson, W.

    1977-08-01

    The University of California at San Diego Auroral Particles Experiment on the ATS-6 Satellite in synchronous orbit has detected a low-energy plasma population which is separate and distinct from both the ring current and plasma sheet populations. These observations suggest that this plasma is the outer zone of the plasmasphere. During magnetically active periods, this low energy plasma is often observed flowing sunward. In the dusk sector, enhanced plasma flow is often observed for 1-2 hours prior to the onset of a substorm-associated particle injection. (author)

  9. Low-energy meson physics (chiral theory)

    International Nuclear Information System (INIS)

    Volkov, M.K.; Pervushin, V.N.

    1976-01-01

    A quantum chiral theory which allows to obtain low-energy expansions of various hadron processes without introducing arbitrary parameters into the theory with the exception of hadron masses and interaction constants is presented. A hypothesis about the dynamic symmetry of strong interactions is suggested. The interaction lagrangian is derived which satisfies conditions of the dynamic symmetry. Examples of the use of the quantum chiral theory for describing low-energy processes of meson interaction are given. It is noted that the results obtained reproduce the actual qualitative pattern of various physical processes and in most cases result in good quantitative agreement with experiments

  10. Interstellar propagation of low energy cosmic rays

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1975-01-01

    Wave particles interactions prevent low energy cosmic rays from propagating at velocities much faster than the Alfven velocity, reducing their range by a factor of order 50. Therefore, supernovae remnants cannot fill the neutral portions of the interstellar medium with 2 MeV cosmic rays [fr

  11. Virtual compton scattering at low energy

    International Nuclear Information System (INIS)

    Lhuillier, D.

    1997-09-01

    The work described in this PhD is a study of the Virtual Compton scattering (VCS) off the proton at low energy, below pion production threshold. Our experiment has been carried out at MAMI in the collaboration with the help of two high resolution spectrometers. Experimentally, the VCS process is the electroproduction of photons off a liquid hydrogen target. First results of data analysis including radiative corrections are presented and compared with low energy theorem prediction. VCS is an extension of the Real Compton Scattering. The virtuality of the incoming photon allows us to access new observables of the nucleon internal structure which are complementarity to the elastic form factors: the generalized polarizabilities (GP). They are function of the squared invariant mass of the virtual photo. The mass limit of these observables restore the usual electric and magnetic polarizabilities. Our experiment is the first measurement of the VCS process at a virtual photon mass equals 0.33 Ge V square. The experimental development presents the analysis method. The high precision needed in the absolute cross-section measurement required an accurate estimate of radiative corrections to the VCS. This new calculation, which has been performed in the dimensional regulation scheme, composes the theoretical part of this thesis. At low q', preliminary results agree with low energy theorem prediction. At higher q', substraction of low energy theorem contribution to extract GP is discussed. (author)

  12. Physics with low energy pions and muons

    International Nuclear Information System (INIS)

    Konijn, J.

    1981-01-01

    This document is a collection of texts used for a course of lectures given by the author at the Technical University of Delft (NL) in 1981. It is therefore a comprehensive, Dutch language, review article starting with the discovery of pions and muons, describing their properties and finally discussing their applications in low energy physics. (C.F.)

  13. Cooking exhaust systems for low energy dwellings

    NARCIS (Netherlands)

    Jacobs, P.; Borsboom, W.A.

    2017-01-01

    Especially in airtight low energy dwellings exhaust systems are of utmost importance as cooking can be a major source of PM2.5 exposure. Dwellings should be designed including facilities enabling extraction of at least 83 dm3/s (300 m3/h) directly to outside. Residents should be able to select an

  14. Low energy antiproton experiments - A review

    NARCIS (Netherlands)

    Jungmann, KP; Yamazaki, Y; Wada, M

    2005-01-01

    Low energy antiprotons offer excellent opportunities to study properties of fundamental forces and symmetries in nature. Experiments with them can contribute substantially to deepen our fundamental knowledge in atomic, nuclear and particle physics. Searches for new interactions can be carried out by

  15. The Simbol-X Low Energy Detector

    International Nuclear Information System (INIS)

    Lechner, Peter

    2009-01-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  16. The Simbol-X Low Energy Detector

    Science.gov (United States)

    Lechner, Peter

    2009-05-01

    For the Low Energy Detector of Simbol-X a new type of active pixel sensor based on the integrated amplifier DEPFET has been developed. This concept combines large area, scalable pixel size, low noise, and ultra-fast readout. Flight representative prototypes have been processed with a performance matching the Simbol-X specifications and demonstrating the technology readiness.

  17. Large solid angle detectors (low energy)

    International Nuclear Information System (INIS)

    L'Hote, D.

    1988-01-01

    This lecture deals with large solid angle detectors used in low energy experiments (mainly in Nuclear Physics). The reasons for using such detectors are discussed, and several basic principles of their design are presented. Finally, two examples of data analysis from such detectors are given [fr

  18. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  19. Studies in Low-Energy Nuclear Science

    Energy Technology Data Exchange (ETDEWEB)

    Carl R. Brune; Steven M. Grimes

    2010-01-13

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187.

  20. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    International Nuclear Information System (INIS)

    King, F; Kruppi, T; Müller, J; Dörner, R; Schmidt, L Ph H; Schmidt-Böcking, H; Stiebing, K E

    2015-01-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections. (paper)

  1. Comparison Study on Low Energy Physics Model of GEANT4

    International Nuclear Information System (INIS)

    Park, So Hyun; Jung, Won Gyun; Suh, Tae Suk

    2010-01-01

    The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2

  2. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    Science.gov (United States)

    King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.

    2015-11-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.

  3. Low energy intense electron beams with extra-low energy spread

    International Nuclear Information System (INIS)

    Aleksandrov, A.V.; Calabrese, R.; Ciullo, G.; Dikansky, N.S.; Guidi, V.; Kot, N.C.; Kudelainen, V.I.; Lamanna, G.; Lebedev, V.A.; Logachov, P.V.; Tecchio, L.; Yang, B.

    1994-01-01

    Maximum achievable intensity for low energy electron beams is a feature that is not very often compatible with low energy spread. We show that a proper choice of the source and the acceleration optics allows one to match them together. In this scheme, a GaAs photocathode excited by a single-mode infrared laser and adiabatic acceleration in fully magnetised optics enables the production of a low-energy-spread electron beam with relatively high intensity. The technological problems associated with the method are discussed together with its limitations. (orig.)

  4. Experimentation with low-energy positron beams

    International Nuclear Information System (INIS)

    Mills, A.P. Jr.

    1983-01-01

    The capability of studying the interactions of positrons with surfaces has recently been exploited by using ultra-high-vacuum techniques. The result has been a new understanding of how positrons interact with surfaces and because of this we are now able to make much stronger fluxes of slow positrons. The higher beam strengths in turn are opening up new possibilities for experimentation on surfaces and solids and for studying the atomic physics of positronium and positron-molecule scattering at low energies. The lectures are intended to review some of the history of this subject and to outline the present state of our knowledge of experimentation with low-energy positron beams. (orig./TW)

  5. Natural gas in low energy house Zittau

    International Nuclear Information System (INIS)

    Maertens, L.; Koschack, A.

    1999-01-01

    This paper describes a low-energy house in Zittau, Germany. The house consists of two parts A and B. Part A is heated by means of gas boilers and condensed boilers, while part B is solar heated. Energy for heating and warming of tap water is an important part of the primary energy consumption in Germany. Therefore, one way of reducing the CO2 emissions is to reduce the heat losses of buildings through outer facades and air ventilation, to use regenerative energy sources, to use fuels with low CO2 emissivity like natural gas, and to install efficient heating- and hot water preparation systems. The low-energy house in Zittau is used for energy research

  6. LINAC4 low energy beam measurements

    CERN Document Server

    Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

    2012-01-01

    Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

  7. Enhancement mechanisms of low energy nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L. [Joint Institute for Nuclear Research, JINR, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation)

    2006-07-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong.

  8. Enhancement mechanisms of low energy nuclear reactions

    International Nuclear Information System (INIS)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L.

    2006-01-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong

  9. A Low-Energy Ring Lattice Design

    International Nuclear Information System (INIS)

    Cai, Yunhai

    2002-01-01

    The PEP-N project at SLAC [1] consists of a Very Low-Energy small electron Ring (VLER) that will collide with the low-energy 3.1 GeV positron beam (LER) of PEP-II, producing center-of-mass energies between the 1.1 GeV and the J/ψ. The beams will collide head-on and will be separated in the detector magnetic field which is part of the Interaction Region [2]. The IP β functions were chosen such as to optimize both luminosity and beam-beam tune shifts, while keeping the LER tune shifts small. This paper describes the lattice design of the VLER for the ''baseline'' at 500 MeV

  10. Food irradiation by low energy electrons

    International Nuclear Information System (INIS)

    Bird, J.R.

    1985-01-01

    For some special cases, the use of low energy electrons has advantages over the use of gamma-rays or higher energy electrons for the direct irradiation of food. These advantages arise from details of the interaction processes which are responsible for the production of physical, chemical and biological effects. Factors involved include depth of penetration, dose distribution, irradiation geometry, the possible production of radioactivity and costs

  11. Architectural Quality of Low Energy Houses

    DEFF Research Database (Denmark)

    Lauring, Michael; Marsh, Rob

    2008-01-01

    This paper expounds a systematic vocabulary concerning architectural quality in houses in general and low energy houses in particular. The vocabulary consists of nine themes. Inside each theme, examples are given of how to achieve both architectural quality and good environmental performance....... The purpose is to provide a useful tool for communication and argumentation in order to further integrated design of houses with good architecture and good environmental performance. ...

  12. Physics with ultra-low energy antiprotons

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Holzscheiter, M.H.; Hughes, R.J.

    1989-01-01

    The experimental observation that all forms of matter experience the same gravitational acceleration is embodied in the weak equivalence principle of gravitational physics. However no experiment has tested this principle for particles of antimatter such as the antiproton or the antihydrogen atom. Clearly the question of whether antimatter is in compliance with weak equivalence is a fundamental experimental issue, which can best be addressed at an ultra-low energy antiproton facility. This paper addresses the issue. 20 refs

  13. PHYSICS WITH ULTRA-LOW ENERGY ANTIPROTONS

    Energy Technology Data Exchange (ETDEWEB)

    M. HOLZSCHEITER

    2001-02-01

    In this report the author describes the current status of the antiproton deceleration (AD) facility at CERN, and highlights the physics program with ultra-low energy antiproton at this installation. He also comments on future possibilities provided higher intensity antiproton beams become available at Fermilab, and review possibilities for initial experiments using direct degrading of high energy antiprotons in material has been developed and proven at CERN.

  14. Workshop on low energy neutrino physics

    International Nuclear Information System (INIS)

    2009-01-01

    The main topics of the workshop are: the determination of the neutrino mixing angle theta-13, the experiments concerning the monitoring of reactors based on the measurement of neutrino spectra, solar neutrinos, supernovae neutrinos, geo-neutrinos, neutrino properties, neutrinoless double beta decay and future low energy neutrino detectors. This document gathers together the program of the workshop, the slides of the presentations, some abstracts and some posters

  15. The low-energy experiment on EXOSAT

    International Nuclear Information System (INIS)

    Bleeker, J.A.M.

    1975-01-01

    The present concept of the Low-Energy-Experiment (LEE) for EXOSAT was proposed by a collaboration of the X-ray astronomy groups at Mullard Space Science Laboratories at University College London, the Space Research Laboratory at Utrecht and the Cosmic Ray Working Group at Leiden. In the following paragraphs the major characteristics of the instrumentation and the expected scientific return will be discussed. The summary comprises both the approved baseline configuration and the proposed option of a small imaging telescope

  16. FLSR - The Frankfurt low energy storage ring

    International Nuclear Information System (INIS)

    Stiebing, K.E.; Alexandrov, V.; Doerner, R.; Enz, S.; Kazarinov, N.Yu.; Kruppi, T.; Schempp, A.; Schmidt Boecking, H.; Voelp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-01-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut fuer Kernphysik der Johann Wolfgang Goethe-Universitaet Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  17. Low-energy scattering data for oxygen

    International Nuclear Information System (INIS)

    Kopecky, S.; Plompen, A.J.M.

    2014-01-01

    A survey of literature data of the scattering lengths of oxygen is performed, and these values are compared to low-energy precise total cross-section data. To check the quality of the data and the correctness of the relation between coherent scattering lengths and low-energy total cross-sections the situation is examined first for carbon. A value and uncertainty for the coherent scattering length of oxygen is recommended for use in future evaluations of 16 O. This coherent scattering length is fully consistent with the high-precision, low-energy total cross-section data. The consistency requires the use of a larger uncertainty than claimed in the most accurate cross-section papers. This larger uncertainty is nevertheless very small and well within the requirements of applications of this cross-section. The recommended value is b c ( 16 O) = 5.816±0.015 fm and the associated total cross-section for the neutron-energy range 0.5 to 2 000 eV is 3.765±0.025 b. The stated uncertainties are one standard deviation total uncertainty. (authors)

  18. Targeting Low-Energy Ballistic Lunar Transfers

    Science.gov (United States)

    Parker, Jeffrey S.

    2010-01-01

    Numerous low-energy ballistic transfers exist between the Earth and Moon that require less fuel than conventional transfers, but require three or more months of transfer time. An entirely ballistic lunar transfer departs the Earth from a particular declination at some time in order to arrive at the Moon at a given time along a desirable approach. Maneuvers may be added to the trajectory in order to adjust the Earth departure to meet mission requirements. In this paper, we characterize the (Delta)V cost required to adjust a low-energy ballistic lunar transfer such that a spacecraft may depart the Earth at a desirable declination, e.g., 28.5(white bullet), on a designated date. This study identifies the optimal locations to place one or two maneuvers along a transfer to minimize the (Delta)V cost of the transfer. One practical application of this study is to characterize the launch period for a mission that aims to launch from a particular launch site, such as Cape Canaveral, Florida, and arrive at a particular orbit at the Moon on a given date using a three-month low-energy transfer.

  19. The Low-Energy Neutrino Factory

    International Nuclear Information System (INIS)

    Brass, Alan; Geer, Steve; Ellis, Malcolm; Mena, Olga; Pascoli, Silvia

    2008-01-01

    To date most studies of Neutrino Factories have focused on facilities where the energy of the muon in the storage ring has been in the range of 25-50 GeV. In this paper we present a concept for a Low-Energy (∼ 4 GeV) neutrino factory. For baselines of O(1000 km), the rich oscillation pattern at low neutrino interaction energy (0.5 - ∼3 GeV) provides the unique performance of this facility with regard to its sensitivity to CP violation and the determination of the neutrino mass hierarchy. A unique neutrino detector is needed, however, in order to exploit this oscillation pattern. We will describe the basic accelerator facility, demonstrate the methodology of the analysis and give an estimate on how well the Low-Energy neutrino factory can measure θ 13 , CP violation and the mass hierarchy. We will also describe the detector concept that is used, show a preliminary analysis regarding its performance and indicate what R and D is still needed. Finally we will show how the Low-Energy neutrino factory could be a step towards an energy frontier muon collider.

  20. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1991-01-01

    A major accomplishment of this project in the past year is the completion of a fairly comprehensive paper describing the survey of radiative capture reactions of protons on light nuclei at low energies. In addition we have completed a preliminary set of measurements of (d,p)/(d,α) cross section ratios on the charge symmetric nuclei 6 Li and 10 B as a test of the Oppenheimer-Phillips effect. While the 6 Li data remain inconclusive, the 10 B data show solid evidence for the Oppenheimer-Phillips enhancement of the (d,p) reaction relative to the (d,α) reaction for deuteron bombarding energies below about 100 keV. We have continued our investigation of fusion reaction products from deuterium-metal systems at room temperatures with the startling observation of intense burst of energetic charged particles from deuterium gas loaded thin titaium foils subject to non-equilibrium thermal and electrical conditions. We have completed two projects involving the application of the low energy particle accelerator to material science problems; firstly a study of the transformation of crystalline to amorphous Fe-Zr systems by proton irradiation and secondly the effects of ion bombardment on the critical temperature of YBCO high-temperature superconductors. Finally we have made progress in several instrumentation projects which will be used in some of the up-coming measurements of nuclear cross sections at very low energies

  1. Improving Indoor Localization Using Bluetooth Low Energy Beacons

    Directory of Open Access Journals (Sweden)

    Pavel Kriz

    2016-01-01

    Full Text Available The paper describes basic principles of a radio-based indoor localization and focuses on the improvement of its results with the aid of a new Bluetooth Low Energy technology. The advantage of this technology lies in its support by contemporary mobile devices, especially by smartphones and tablets. We have implemented a distributed system for collecting radio fingerprints by mobile devices with the Android operating system. This system enables volunteers to create radio-maps and update them continuously. New Bluetooth Low Energy transmitters (Apple uses its “iBeacon” brand name for these devices have been installed on the floor of the building in addition to existing WiFi access points. The localization of stationary objects based on WiFi, Bluetooth Low Energy, and their combination has been evaluated using the data measured during the experiment in the building. Several configurations of the transmitters’ arrangement, several ways of combination of the data from both technologies, and other parameters influencing the accuracy of the stationary localization have been tested.

  2. Nuclear data and low energy nuclear research in Israel

    International Nuclear Information System (INIS)

    Yiftah, S.

    1978-07-01

    The Israel Nuclear Data and Low Energy Nuclear Research relevant to the International Nuclear Data Committee was continued in the various institutions listed in previous Progress Reports (LS-270 for 1976). The latest major experimental facility, the 14 UD pelletron, was installed in the Koffler Accelerator Tower at the Weizmann Institute of Science, Rehovot, and accepted on April 1st 1977. A report in Revue de Physique Appliquee of October 1977 including a description of the facility, acceptance performance, as well as some supplementary devices, is reproduced in the beginning of this report. Brief abstracts of the research work, both published and unpublished, are presented. (author)

  3. Development of real-time low energy electron calorimeter

    International Nuclear Information System (INIS)

    Noriah Mod Ali; Smith, F.A.

    1999-01-01

    A low energy electron beam calorimeter with a thin film window has been fabricated to facilitate a reliable method of dose assessment for electron beam energies down to 200 keV. The system was designed to incorporate a data-logger in order that it could be used on the self-shielded 200 keV facility at MINT. In use, the calorimeter started logging temperature a short time before it passed under the beam and it continued taking data until well after the end of the irradiation. Data could be retrieved at any time after the calorimeter had emerged from the irradiator

  4. Dosimetry of low-energy beta radiation

    International Nuclear Information System (INIS)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

  5. Hydrogen-antihydrogen interactions at low energies

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Carr, J.M.; Zeman, V.

    1999-01-01

    The main cause of loss of trapped AH is due to collisions with H 2 and He. As a first step towards treating these reactions we are studying the interaction of AH with H. We have carried out variational calculations to determine an upper bound to the smallest internuclear distance at which the light particles are still bound to the nuclei. We are currently in the process of taking into account the motion of the nuclei. This will enable us to calculate cross-sections for low energy H-AH scattering

  6. The low energy booster project status

    International Nuclear Information System (INIS)

    Tuttle, G.W.

    1993-05-01

    In order to achieve the required injection momentum, the Superconducting Super Collider (SSC) has an accelerator chain comprised of a Linear Accelerator and three synchrotrons. The Low Energy Booster (LEB) is the first synchrotron in this chain. The LEB project has made significant progress in the development of major subsystems and conventional construction. This paper briefly reviews the performance requirements of the LEB and describes significant achievements in each of the major subsystem areas. Highlighted among these achievements are the LEB foreign collaborations with the Budker Institute of Nuclear Physics (BINP) located in Novosibirsk, Russia

  7. Low energy constraints and scalar leptoquarks⋆

    Directory of Open Access Journals (Sweden)

    Fajfer Svjetlana

    2014-01-01

    Full Text Available The presence of a colored weak doublet scalar state with mass below 1 TeV can provide an explanation of the observed branching ratios in B → D(∗τντ decays. Constraints coming from Z → bb̄, muon g − 2, lepton flavor violating decays are derived. The colored scalar is accommodated within 45 representation of SU(5 group of unification. We show that presence of color scalar can improve mass relations in the up-type quark sector mass. Impact of the colored scalar embedding in 45-dimensional representation of SU(5 on low-energy phenomenology is also presented.

  8. Round Gating for Low Energy Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things....... Additionally, we discuss how to needed gating wave can be generated. Experimental results show that our technique is able to reduce the energy consumption in most block ciphers by over 60% while incurring only a minimal overhead in hardware....

  9. Low-energy phenomenological chiral Lagrangians

    International Nuclear Information System (INIS)

    Cavopol, A.V.

    1987-01-01

    We develop a phenomenological Lagrangian that satisfies the requirements of the so called alternative schemes designed to model low energy meson phenomenology. Linear and nonlinear σ type Lagrangians and symmetry breaking schemes are used to describe pions that exhibit masses proportional to the square of the symmetry breaking term's coefficient, ε. (m π 2 ∼ 0(ε 2 )). The invariance of the theory under coordinate dependent transformations is achieved by introducing gauge fields for both linear and nonlinear Lagrangians. Finally, analogies between the minimal symmetry breaking terms in Quantum Electrodynamics and in our phenomenological lagrangians are used to generate a discussion of the quark-pion mass dependence indicated by the model

  10. FLSR - The Frankfurt low energy storage ring

    Science.gov (United States)

    Stiebing, K. E.; Alexandrov, V.; Dörner, R.; Enz, S.; Kazarinov, N. Yu.; Kruppi, T.; Schempp, A.; Schmidt Böcking, H.; Völp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-02-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut für Kernphysik der Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  11. Application of Decomposition Methodology to Solve Integrated Process Design and Controller Design Problems for Reactor-Separator-Recycle System

    DEFF Research Database (Denmark)

    Abd.Hamid, Mohd-Kamaruddin; Sin, Gürkan; Gani, Rafiqul

    2010-01-01

    This paper presents the integrated process design and controller design (IPDC) for a reactor-separator-recycle (RSR) system and evaluates a decomposition methodology to solve the IPDC problem. Accordingly, the IPDC problem is solved by decomposing it into four hierarchical stages: (i) pre...... the design of a RSR system involving consecutive reactions, A B -> C and shown to provide effective solutions that satisfy design, control and cost criteria. The advantage of the proposed methodology is that it is systematic, makes use of thermodynamic-process knowledge and provides valuable insights......-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection and verification. The methodology makes use of thermodynamic-process insights and the reverse design approach to arrive at the final process-controller design decisions. The developed methodology is illustrated through...

  12. Low-energy QCD and ultraviolet renormalons

    International Nuclear Information System (INIS)

    Peris, S.

    1997-01-01

    We discuss the contribution of ultraviolet (UV) renormalons in QCD to two-point functions of quark current operators. This explicitly includes effects due to the exchange of one renormalon chain as well as two chains. It is shown that, when the external Euclidean momentum of the two-point functions becomes smaller than the scale Λ L associated with the Landau singularity of the QCD one-loop running coupling constant, the positions of the UV renormalons in the Borel plane become true singularities in the integration range of the Borel transform. This introduces ambiguities in the evaluation of the corresponding two-point functions. The ambiguities associated with the leading UV renormalon singularity are of the same type as the contribution due to the inclusion of dimension d=6 local operators in a low-energy effective Lagrangian valid at scales smaller than Λ L . We then discuss the inclusion of an infinite number of renormalon chains and argue that the previous ambiguity hints at a plausible approximation scheme for low-energy QCD, resulting in an effective Lagrangian similar to the one of the extended Nambu-Jona-Lasinio (ENJL) model of QCD at large N c . (orig.)

  13. Low energy accelerators for research and applications

    International Nuclear Information System (INIS)

    Bhandari, R.K.

    2013-01-01

    Charged particle accelerators are instruments for producing a variety of radiations under controlled conditions for basic and applied research as well as applications. They have helped enormously to study the matter, atoms, nuclei, sub-nuclear particles and their constituents, forces involved in the related phenomena etc. No other man-made instrument has been so effective in such studies as the accelerator. The large accelerator constructed so far is the Large Hadron Collider (LHC) housed in a tunnel of 27 km circumference, while a small accelerator can fit inside a room. Small accelerators accelerate charged particles such as electrons, protons, deuterons, alphas and, in general ions to low energy, generally, below several MeV. These particle beams are used for studies in nuclear astrophysics, atomic physics, material science, surface physics, bio sciences etc. They are used for ion beam analysis such as RBS, PIXE, NRA, AMS, CPAA etc. More importantly, the ion beams have important industrial applications like ion implantation, surface modification, isotope production etc. while electron beams are used for material processing, material modification, sterilization, food preservation, non destructive testing etc. In this talk, role of low energy accelerators in research and industry as well as medicine will be discussed. (author)

  14. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2010-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187. We describe here research into low-energy nuclear reactions and structure. The statistical properties of nuclei have been studied by measuring level densities and also calculating them theoretically. Our approach of measuring level densities via evaporation spectra is able to reach a very wide range of nuclei by using heavy ion beams (we expect to develop experiments using radioactive beams in the near future). Another focus of the program has been on γ-ray strength functions. These clearly impact nuclear reactions, but they are much less understood than corresponding transmission coefficients for nucleons. We have begun investigations of a new approach, using γ-γ coincidences following radiative capture. Finally, we have undertaken several measurements of cross sections involving light nuclei which are important in various applications. The 9 Be(α,n) and B(d,n) reactions have been measured at Ohio University, while neutron-induced reactions have been measured at Los Alamos (LANSCE).

  15. Low energy theorems of hidden local symmetries

    International Nuclear Information System (INIS)

    Harada, Masayasu; Kugo, Taichiro; Yamawaki, Koichi.

    1994-01-01

    We prove to all orders of the loop expansion the low energy theorems of hidden local symmetries in four-dimensional nonlinear sigma models based on the coset space G/H, with G and H being arbitrary compact groups. Although the models are non-renormalizable, the proof is done in an analogous manner to the renormalization proof of gauge theories and two-dimensional nonlinear sigma models by restricting ourselves to the operators with two derivatives (counting a hidden gauge boson field as one derivative), i.e., with dimension 2, which are the only operators relevant to the low energy limit. Through loop-wise mathematical induction based on the Ward-Takahashi identity for the BRS symmetry, we solve renormalization equation for the effective action up to dimension-2 terms plus terms with the relevant BRS sources. We then show that all the quantum corrections to the dimension-2 operators, including the finite parts as well as the divergent ones, can be entirely absorbed into a re-definition (renormalization) of the parameters and the fields in the dimension-2 part of the tree-level Lagrangian. (author)

  16. Low Energy Nuclear Reactions: 2007 Update

    Science.gov (United States)

    Krivit, Steven B.

    2007-03-01

    This paper presents an overview of low energy nuclear reactions, a subset of the field of condensed matter nuclear science. Condensed matter nuclear science studies nuclear effects in and/or on condensed matter, including low energy nuclear reactions, an entirely new branch of science that gained widespread attention and notoriety beginning in 1989 with the announcement of a previously unrecognized source of energy by Martin Fleischmann and Stanley Pons that came to be known as cold fusion. Two branches of LENR are recognized. The first includes a set of reactions like those observed by Fleischmann and Pons that use palladium and deuterium and yield excess heat and helium-4. Numerous mechanisms have been proposed to explain these reactions, however there is no consensus for, or general acceptance of, any of the theories. The claim of fusion is still considered speculative and, as such, is not an ideal term for this work. The other branch is a wide assortment of nuclear reactions that may occur with either hydrogen or deuterium. Anomalous nuclear transmutations are reported that involve light as well as heavy elements. The significant questions that face this field of research are: 1) Are LENRs a genuine nuclear reaction? 2) If so, is there a release of excess energy? 3) If there is, is the energy release cost-effective?

  17. Low energy cyclotron for radiocarbon dating

    International Nuclear Information System (INIS)

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14 C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14 C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14 C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

  18. Experimental perspectives in low energy lepton physics

    International Nuclear Information System (INIS)

    Fiorini, E.

    1986-01-01

    Low energy nuclear physics has been and is going to be an essential tool for the study of weak interaction and neutrino physics. The use of the atomic nucleus as a ''microlaboratory'' with well defined quantum numbers is undoubtedly going to yield important and sometimes perhaps unexpected results on the symmetry laws governing the subnuclear world. These searches are however very hard experimentally and the bottleneck on obtaining more stringent results only rarely depends on the need of large and expensive apparatuses as those used in high energy physics: more limiting are technical difficulties. The author believes therefore that a real break-through to overcome the present experimental limitations can only be obtained with totally new and sometime ''non canonical'' technical approaches. This paper is an admittedly incomplete discussion of some of them. The author considers separately searches for rare decays, detection of low energy neutrinos and measurements of the neutrino mass, even if some of these new techniques are common to more than one of these subjects

  19. Beam diagnostics for low energy beams

    Directory of Open Access Journals (Sweden)

    J. Harasimowicz

    2012-12-01

    Full Text Available Low-energetic ion and antimatter beams are very attractive for a number of fundamental studies. The diagnostics of such beams, however, is a challenge due to low currents down to only a few thousands of particles per second and significant fraction of energy loss in matter at keV beam energies. A modular set of particle detectors has been developed to suit the particular beam diagnostic needs of the ultralow-energy storage ring (USR at the future facility for low-energy antiproton and ion research, accommodating very low beam intensities at energies down to 20 keV. The detectors include beam-profile monitors based on scintillating screens and secondary electron emission, sensitive Faraday cups for absolute intensity measurements, and capacitive pickups for beam position monitoring. In this paper, the design of all detectors is presented in detail and results from beam measurements are shown. The resolution limits of all detectors are described and options for further improvement summarized. Whilst initially developed for the USR, the instrumentation described in this paper is also well suited for use in other low-intensity, low-energy accelerators, storage rings, and beam lines.

  20. Occupant satisfaction with new low-energy houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Jensen, Ole Michael; Kristensen, Lars

    2012-01-01

    The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low-energy ho......The development and the erection of low-energy buildings have been intensified in recent years. Still, there are only few studies of the energy performance and occupant satisfaction with living in low-energy houses. A questionnaire survey was therefore carried out among occupants of low......-energy houses. The purpose was to study occupant satisfaction with new low-energy houses concerning i.a. the perceived indoor climate and the technical installations for heating and ventilation. The survey showed an overall satisfaction with the new low-energy houses, but also that there were problems...... occupant satisfaction in existing and future low-energy houses are given....

  1. Nuclear Computational Low Energy Initiative (NUCLEI)

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Sanjay K. [University of Washington

    2017-08-14

    This is the final report for University of Washington for the NUCLEI SciDAC-3. The NUCLEI -project, as defined by the scope of work, will develop, implement and run codes for large-scale computations of many topics in low-energy nuclear physics. Physics to be studied include the properties of nuclei and nuclear decays, nuclear structure and reactions, and the properties of nuclear matter. The computational techniques to be used include Quantum Monte Carlo, Configuration Interaction, Coupled Cluster, and Density Functional methods. The research program will emphasize areas of high interest to current and possible future DOE nuclear physics facilities, including ATLAS and FRIB (nuclear structure and reactions, and nuclear astrophysics), TJNAF (neutron distributions in nuclei, few body systems, and electroweak processes), NIF (thermonuclear reactions), MAJORANA and FNPB (neutrino-less double-beta decay and physics beyond the Standard Model), and LANSCE (fission studies).

  2. Redesign of a Low Energy Probe Head

    CERN Document Server

    Rao, Yi-Nong; Ries, Thomas

    2005-01-01

    The present situation of the low energy probe LE2 in TRIUMF cyclotron is that the thickness of the finger 5 is uniform over a radial length of 3.25 inch and its weight which amounts to ~447 g is affecting its re-circulating ball mechanism and causing it to fall below the median plane over its range of movement. We therefore re-design it in order to reduce its weight. First, we made simulations and determined the optimum thickness of the probe head vs its radial length. These simulation results are found to be in good agreement with experimental measurements made. Finally, we calculated the temperature rise caused by the beam power dumped on the probe, and figured out the maximum current of beam that can be dumped on the finger.

  3. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  4. Low-energy pion-nucleon scattering

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Ai, L.; Kaufmann, W.B.

    1998-01-01

    An analysis of low-energy charged pion-nucleon data from recent π ± p experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of f 2 =0.0756±0.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P 31 and P 13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the Σ term. Off-shell amplitudes are also provided. copyright 1998 The American Physical Society

  5. Low energy ion-molecule reactions

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, J.M. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project is concerned with elucidating the dynamics of elementary ion-molecule reactions at collision energies near and below 1 eV. From measurements of the angular and energy distributions of the reaction products, one can infer intimathe details about the nature of collisions leading to chemical reaction, the geometries and lifetimes of intermediate complexes that govern the reaction dynamics, and the collision energy dependence of these dynamical features. The author employs crossed-beam low energy mass spectrometry technology developed over the last several years, with the focus of current research on proton transfer and hydrogen atom transfer reactions of te O{sup {minus}} ion with species such as HF, H{sub 2}O, and NH{sub 3}.

  6. Knowledge from the low energy results

    International Nuclear Information System (INIS)

    Gosset, J.

    1988-01-01

    Before being used at very high energies, in order to search for the quark-gluon plasma, nucleus-nucleus central collisions have been studied at low energy, between about 20 MeV per nucleon and 10 GeV per nucleon, with the same objective to explore the phase diagram of nuclear matter, but in a regime where both temperature and energy are too small for plasma formation. Approaching this very complicated problem of nuclear physics led to many difficulties. They are first reviewed, and various means developed in order to solve them are considered. These difficulties are then detailed along discussions about temperature and nuclear collective flow. Temperature is a concept which is commonly used but also a quantity which is difficult to measure. Nuclear collective flow is a very interesting compression effect; it has been observed experimentally after being predicted theoretically, but its interpretation in terms of the nuclear matter equation of state remains quite difficult [fr

  7. Windows in Low Energy Houses. Size Matters

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Mari-Louise

    2004-06-01

    A generally accepted way of building passive houses has been to have small windows facing north and a large glass facade to the south. This is to minimize losses on the north side while gaining as much solar heat as possible on the south. In spring 2001, twenty terraced houses were built outside Goeteborg partly in this way. The indoor temperature is kept at a comfortable level by passive methods, using solar gains and internal gains from household appliances and occupants. Heat losses are very low, since the building envelope is well insulated and since modern coated triple-glazed windows have been installed. The purpose of this work is to investigate how decreasing the window size facing south and increasing the window size facing north in low energy houses will influence the energy consumption and maximum power needed to keep the indoor temperature between 23 and 26 deg C. Different climates and orientations have been investigated and so have the influence of occupancy and window type. A dynamic building simulation tool, DEROB, has been used and the simulations indicate an extremely low energy demand for the houses. The results show that the size of the energy efficient windows does not have a major influence on the heating demand in winter, but is of relevant signification looking at the cooling need in summer. This indicates that instead of the traditional technique of building passive houses it is possible to enlarge the window area facing north and get better lighting conditions. To decrease the energy need for cooling, there is an optimal window size facing south that is smaller than the original size of the investigated buildings.

  8. Low energy demonstration accelerator technical area 53

    International Nuclear Information System (INIS)

    1996-01-01

    As part of the Department of Energy's (DOE) need to maintain the capability of producing tritium in support of its historic and near-term stewardship of the nation's nuclear weapons stockpile, the agency has recently completed a Programmatic Environmental Impact Statement for Tritium Supply and Recycling. The resulting Record of Decision (ROD) determined that over the next three years the DOE would follow a dual-track acquisition strategy that assures tritium production for the nuclear weapon stockpile in a rapid, cost effective, and safe manner. Under this strategy the DOE will further investigate and compare two options for producing tritium: (1) purchase of an existing commercial light-water reactor or irradiation services with an option to purchase the reactor for conversion to a defense facility; and (2) design, build, and test critical components of a system for accelerator production of tritium (APT). The final decision to select the primary production option will be made by the Secretary of Energy in the October 1998 time frame. The alternative not chosen as the primary production method, if feasible, would be developed as a back-up tritium supply source. This Environmental Assessment (EA) analyzes the potential environmental effects that would be expected to occur if the DOE were to design, build, and test critical prototypical components of the accelerator system for tritium production, specifically the front-end low-energy section of the accelerator, at Los Alamos National Laboratory. The Low Energy Demonstration Accelerator (LEDA) would be incrementally developed and tested in five separate stages over the next seven years. The following issues were evaluated for the proposed action: utility demands, air, human health, environmental restoration, waste management, transportation, water, threatened and endangered species, wetlands, cultural resources, and environmental justice

  9. Colorado School of Mines low energy nuclear physics project

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1993-01-01

    This report summarizes the accomplishments of the project ''Studies of nuclear reactions at very low energies''. This project was undertaken in 1987 and completed in 1993. All but one of the major objectives of this study have been accomplished. Specifically the authors have completed their investigation of the (p,γ) on light nuclei, a study of the Oppenheimer-Phillips effect, a measurements of the astrophysically interesting reaction D(α,γ) 6 Li at low energies and an extension of the reaction D(d,γ) 4 He to lower energies than previously observed. Preliminary investigation of te reaction 7 Li( 3 He,p) 9 Be was begun and is continuing under a separate DOE grant. In addition to these tasks, they have completed some very interesting projects which were not included in the original proposal. These include a study of the (d,γ) reactions on 6 Li, 7 Li and 10 B and an investigation of the possibility of observing terrestrial antineutrinos from the beta decay chains of U and Th as a diagnostic of terrestrial heat flow

  10. Low energy electron scattering from fuels

    International Nuclear Information System (INIS)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M.

    2011-01-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  11. Low energy electron scattering from fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Cristina A.; Silva, Daniel G.M.; Coelho, Rafael F.; Duque, Humberto V.; Santos, Rodrigo R. dos; Ribeiro, Thiago M. [Universidade Federal de Juiz de Fora (UFJF), MG (Brazil). Dept. de Fisica; Yates, Brent; Hong, Ling; Khakoo, Murtadha A. [California State University at Fullerton, CA (US). Physics Department; Bettega, Marcio H.F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Costa, Romarly F. da [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Lima, Marco A.P. [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE/CNPEM), Campinas, SP (Brazil)

    2011-07-01

    Full text. Accurate and precise values of absolute total cross section (TCS) represent important information in many scientific and technological applications. In our case, for example, we are motivated to provide such information for electron-fuel collision processes which are specifically relevant to modeling spark ignition in alcohol-fuelled internal combustion engines. Many electron scattering TCS measurements are presently available for a diverse range of atomic and molecular targets. However, lack of data for important bio-molecular targets still remains. Disagreements between the available TCS data for the alcohols have prompted several studies of electron scattering collision of slow electrons with these molecules which are currently important in applications as bio- fuels. This relevance, which has attracted much attention, has been one of the subjects of a recent collaboration between experimental and theoretical groups in the USA and Brazil. Recently this collaboration reported first measurements and calculations of differential cross sections for elastic low-energy (rotationally unresolved) electron scattering by several primary alcohols. In this work we address methanol and ethanol TCSs at low energy range and report additional studies of resonant structure in ethanol using the detection of metastable states produced by electron impact excitation with high energy resolution. We have recently constructed a TCS apparatus in our laboratory at Universidade Federal de Juiz de Fora, Brazil, based on the well-known linear transmission technique. The experimental setup is based on the measurement of the attenuation of a collimated electron beam through a gas cell containing the atoms or molecules to be studied at a given pressure. It consists essentially of an electron gun, a gas cell and an electron energy analyzer composed of an array of decelerating electrostatic lenses, a cylindrical dispersive 127o analyzer and a Faraday cup. To our knowledge, there exist

  12. Low energy atom-atom collisions

    International Nuclear Information System (INIS)

    Child, M.S.

    1980-01-01

    The semiclassical theory of atom-atom potential scattering and of low energy inelastic atom-atom scattering is reviewed. Particular attention is given to the origin and interpretation of rainbow structure, diffraction oscillations and exchange oscillations in the potential scattering differential cross-section, and to the glory structure and symmetry oscillations in the integral cross-section. Available methods for direct inversion of the cross-section data to recover the potential are reviewed in some detail. The theory of non-adiabatic transitions is introduced by a short discussion of interaction mechanisms and of diabetic and adiabatic representations. Analytical S matrix elements are presented for two state curve-crossing (Landau-Zener-Stuckelberg), Demkov and Nikitin models. The relation between Stuckelberg oscillations in the S matrix and in the differential cross-section is discussed in terms of interference between trajectories belonging to two different classical deflection functions. The energy dependences of the inelastic integral cross-section for curve-crossing and Demkov type transitions are also discussed. Finally the theory is reviewed in relation to a recent close-coupled study of fine structure transitions in F( 2 P) + Xe( 2 S) scattering

  13. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    Brune, Carl R.; Grimes, Steven M.

    2006-01-01

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  14. Low Energy Desalination Using Battery Electrode Deionization

    KAUST Repository

    Kim, Taeyoung

    2017-09-21

    New electrochemical technologies that use capacitive or battery electrodes are being developed to minimize energy requirements for desalinating brackish waters. When a pair of electrodes is charged in capacitive deionization (CDI) systems, cations bind to the cathode and anions bind to the anode, but high applied voltages (>1.2 V) result in parasitic reactions and irreversible electrode oxidation. In the battery electrode deionization (BDI) system developed here, two identical copper hexacyanoferrate (CuHCF) battery electrodes were used that release and bind cations, with anion separation occurring via an anion exchange membrane. The system used an applied voltage of 0.6 V, which avoided parasitic reactions, achieved high electrode desalination capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes between CuHCF electrodes (up to three anion and two cation exchange membranes) reduced energy consumption to only 0.02 kWh/m3 (approximately an order of magnitude lower than values reported for CDI), for an influent desalination similar to CDI (25 mM decreased to 17 mM). These results show that BDI could be effective as a very low energy method for brackish water desalination.

  15. Operating Characteristics of the low energy accelerator

    International Nuclear Information System (INIS)

    Abd El-Baki, M.M.; Abd El-Rahman, M.M.

    2000-01-01

    The main purpose of this work is to describe the construction and operation of low energy accelerator with energy in the range from (zero to 100 KeV.). This accelerator includes an ion source of the cold cathode penning type (with pierce geometry for ion beam extraction), an accelerating tube (with 8 electrodes) and faraday cup for measuring ion current. A vacuum system which gives vacuum of the order 3.0 x 10 8 torr is used. A palladium tube is used to supply the source with pure hydrogen atoms. It was possible to operate this accelerator with an energy 50 KeV. at minimum hydrogen pressure. 6.3 x 10 6 torr. The total resistance applied between the accelerating electrodes R T = 31.5 M OMEGA. These data includes the influence of the pressure in the accelerating tube, the magnetic field of the ion source, the extraction potential and the accelerating potential on the collector ion current. It was possible to accelerate protons with an energy 50 KeV with current about 100 MU A at pressure 6.3 x 10 6 Torr, the source magnetic field + 1100 gauss (I B = 2A), the current = 0.4 A and the extraction potential = 10 K. V

  16. Low energy spin excitations in chromium metal

    International Nuclear Information System (INIS)

    Pynn, R.; Azuah, R.T.; Stirling, W.G.

    1997-01-01

    Neutron scattering experiments with full polarization analysis have been performed with a single crystal of chromium to study the low-energy spin fluctuations in the transverse spin density wave (TSDW) state. A number of remarkable results have been found. Inelastic scattering observed close to the TSDW satellite positions at (1 ± δ,0,0) does not behave as expected for magnon scattering. In particular, the scattering corresponds to almost equally strong magnetization fluctuations both parallel and perpendicular to the ordered moments of the TSDW phase. As the Neel temperature is approached from below, scattering at the commensurate wavevector (1,0,0) increases in intensity as a result of critical scattering at silent satellites (1,0, ± δ) being included within the spectrometer resolution function. This effect, first observed by Sternlieb et al, does not account for all of the inelastic scattering around the (1,0,0) position, however, Rather, there are further collective excitations, apparently emanating from the TSDW satellites, which correspond to magnetic fluctuations parallel to the ordered TSDW moments. These branches have a group velocity that is close to that of (1,0,0) longitudinal acoustic (LA) phonons, but assigning their origin to magneto-elastic scattering raises other unanswered questions

  17. Low energy pion-16O scattering

    International Nuclear Information System (INIS)

    Wafelbakker, C.K.

    1981-01-01

    In spite of some outward appearances, the modern microscopic theories of the pion-nucleus (πA) interaction are not fundamentally very different from each other. They can all be derived from the same source, multiple-scattering theory. They all treat the first-order optical potential in a comparatively detailed way and in all of them it is necessary to incorporate higher-order effects in general and pion-annihilation in particular phenomenologically. Basically the same physical features can be embodied in all of them. The presentation of the theoretical scheme underlying the present thesis is designed to stress this conceptual unity of current πA theory. In this thesis the methods developed by De Kam to incorporate Pauli- and binding-corrections to the impulse-approximation first-order optical potential for 4 He are extended to a more complicated nucleus, 16 O, for the first time. In concreto two situations are considered: π- 16 O scattering at energies below nucleon-knockout threshold (13.5 MeV) - 7 and 12 MeV - and at energies 40 and 49.7 MeV, above nucleon-knockout threshold but still well within the low-energy region. (Auth.)

  18. Low energy scattering with a nontrivial pion

    International Nuclear Information System (INIS)

    Fariborz, Amir H.; Jora, Renata; Schechter, Joseph

    2007-01-01

    An earlier calculation in a generalized linear sigma model showed that the well-known current algebra formula for low energy pion-pion scattering held even though the massless Nambu Goldstone pion contained a small admixture of a two-quark two-antiquark field. Here we turn on the pion mass and note that the current algebra formula no longer holds exactly. We discuss this small deviation and also study the effects of a SU(3) symmetric quark mass type term on the masses and mixings of the eight SU(3) multiplets in the model. We calculate the s-wave scattering lengths, including the beyond current algebra theorem corrections due to the scalar mesons, and observe that the effect of the scalar mesons is to improve the agreement with experiment. In the process, we uncover the way in which linear sigma models give controlled corrections (due to the presence of scalar mesons) to the current algebra scattering formula. Such a feature is commonly thought to exist only in the nonlinear sigma model approach

  19. DOD low energy model installation program

    International Nuclear Information System (INIS)

    Fournier, D.F. Jr.

    1993-01-01

    The Model Low Energy Installation Program is a demonstration of an installation-wide, comprehensive energy conservation program that meets the Department of Defense (DoD) energy management goals of reducing energy usage and costs by at least 20%. It employs the required strategies for meeting these goals, quantifies the environmental compliance benefits resulting from energy conservation and serves as a prototype for DoD wide application. This project will develop both analysis tools and implementation procedures as well as demonstrate the effectiveness of a comprehensive, coordinated energy conservation program based on state-of-the-art technologies. A military installation is in reality a small to medium sized city. It generally has a complete utilities infrastructure including water supply and distribution, sewage collection and treatment, electrical supply and distribution, central heating and cooling plants with thermal distribution, and a natural gas distribution system. These utilities are quite extensive and actually consume about 10-15% of the energy on the facility not counting the energy going into the central plants

  20. Study on the application of low energy U-window

    International Nuclear Information System (INIS)

    Li Binghai; Liu Shikai; Chen Guosheng

    2012-01-01

    For using the low energy U-window information, based on the theory and experiment, the advantage of identifying the subtle anomaly that the low energy U-window information has given is discussed, the method of drawing the low energy U-window information is stated; a method of calibration and obtaining the calibration parameters was developed which was applied to Dongsheng region. The result indicated that the anomaly of low energy U-window information upon known field is more easy identified by comparing with the standard three windows U-window information, which proved the practicability of the method of low energy U-windows information. (authors)

  1. New cooperative mechanisms of low-energy nuclear reactions using super low-energy external field

    International Nuclear Information System (INIS)

    Gareev, F.A.; Zhidkova, I.E.

    2006-01-01

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system. (author)

  2. New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

    Science.gov (United States)

    Gareev, F. A.; Zhidkova, I. E.

    We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

  3. Nuclear data and low energy nuclear research in Israel

    International Nuclear Information System (INIS)

    Yiftah, S.

    1977-04-01

    The Israel Nuclear Data and Low Energy Nuclear Research relevant to the International Nuclear Data Committee was continued in various institutions. The major experimental facilities consist of: A 5 Megawatt swimming pool enriched uranium reactor at the Soreq Nuclear Research Centre; A 26 Megawatt heavy water tank-type natural uranium reactor at the Negev Research Centre; A 6-million volt EN tandem accelerator at the Weizmann Institute of Science, Rehovot; The new most modern high energy 14 UD pelletron accelerator manufactured by the National Electrostatic Corporation of Middleton, Wisconsin, installed inside the Koffler Accelerator Tower at the Weizmann Institute of Science, Rehovot. Brief abstracts of the research work, both published and unpublished, listed according to the various laboratories, are reported in the following pages. (author)

  4. Low energy nuclear reactions: 2007 update

    International Nuclear Information System (INIS)

    Krivit, S. B.

    2007-01-01

    Introduction: This paper presents an overview of the field of low energy nuclear reactions (LENR), a branch of condensed matter nuclear science. It explains some of the various terminologies that have been used to describe this field since it debuted as 'cold fusion' in 1989. The paper also reviews some of the most interesting news and developments regarding low energy nuclear reaction experiments and theory, and some of the sociological and political trends that have affected the field over the last 18 years. It concludes with a list of resources and information for scientists, journalists and decision makers. Understanding the Nature of the Reactions The worldwide LENR research effort includes 200 researchers in 13 nations. Over the last 18 years, 12 international conferences have been held, as well as 7 regional conferences in Italy, 14 in Russia and 7 in Japan. The significant questions that face this field of research are: a) Are LENRs a genuine nuclear reaction? b) If so, is there a release of excess energy? and c) Are transmutations possible? If the answers to these questions turn out to be positive, the next questions will be: d) Is the energy release cost-effective? and e) Are the transmutations useful? Despite the fact that repeatability and reproducibility are challenging, the required parameters for achieving the excess heat effect are well understood. First, a high atomic loading ratio of D into Pd is required. In most conditions, 0.90 is the minimum threshold required to produce an excess heat effect. Second, a high electrical current density in the cathode is needed, 250 mA/cm 2 under most conditions. The third requirement is for some kind of dynamic trigger to impose a deuterium flux in, on or around the cathode. The challenge that researchers face is how to achieve these conditions. Some of the Most Interesting Research Developments Work by Stanislaw Szpak, Pamela Boss and Frank Gordon at the U.S. Navy's SPAWAR Systems Center in San Diego has

  5. Low-energy scattering on the lattice

    International Nuclear Information System (INIS)

    Bour Bour, Shahin

    2014-01-01

    In this thesis we present precision benchmark calculations for two-component fermions in the unitarity limit using an ab initio method, namely Hamiltonian lattice formalism. We calculate the ground state energy for unpolarized four particles (Fermi gas) in a periodic cube as a fraction of the ground state energy of the non-interacting system for two independent representations of the lattice Hamiltonians. We obtain the values 0.211(2) and 0.210(2). These results are in full agreement with the Euclidean lattice and fixed-node diffusion Monte Carlo calculations. We also give an expression for the energy corrections to the binding energy of a bound state in a moving frame. These corrections contain information about the mass and number of the constituents and are topological in origin and will have a broad applications to the lattice calculations of nucleons, nuclei, hadronic molecules and cold atoms. As one of its applications we use this expression and determine the low-energy parameters for the fermion dimer elastic scattering in shallow binding limit. For our lattice calculations we use Luescher's finite volume method. From the lattice calculations we find κa fd =1.174(9) and κr fd =-0.029(13), where κ represents the binding momentum of dimer and a fd (r fd ) denotes the scattering length (effective-range). These results are confirmed by the continuum calculations using the Skorniakov-Ter-Martirosian integral equation which gives 1.17907(1) and -0.0383(3) for the scattering length and effective range, respectively.

  6. Low energy x-ray spectrometer

    International Nuclear Information System (INIS)

    Woodruff, W.R.

    1981-01-01

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

  7. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  8. Low energy beam transport for HIDIF

    International Nuclear Information System (INIS)

    Meusel, O.; Pozimski, J.; Jakob, A.; Lakatos, A.

    2001-01-01

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe + beam are presented and the results of numerical simulations are shown

  9. Low energy beam transport for HIDIF

    Energy Technology Data Exchange (ETDEWEB)

    Meusel, O. E-mail: o.meusel@iap.uni-frankfurt.de; Pozimski, J.; Jakob, A.; Lakatos, A

    2001-05-21

    Low energy beam transport (LEBT) for a heavy ion inertial fusion (HIDIF, I. Hofmann and G. Plass, Report of the European Study Group on Heavy Ion Driven Inertial Fusion for the Period 1995-1998) facility suffers from high space charge forces and high ion mass. Space charge compensation reduces the necessary focusing force of the lenses and the radius of the beam in the LEBT, and therefrom the emittance growth due to aberrations and self fields is reduced. Gabor lenses (D. Gabor, Nature 160 (1947)) providing a stable space charge cloud for focusing and combine strong cylinder symmetric focusing with partly space charge compensation and low emittance growth. A high tolerance against source noise and current fluctuations and reduced investment costs could be other possible advantages. The proof of principle has already been demonstrated (J.A. Palkovic, Measurements on a Gabor lens for Neutralizing and Focusing a 30 keV Proton beam, University of Wisconsin, Madison, 1989; J. Pozimski, P. Gross, R. Doelling and T. Weis, First experimental studies of a Gabor plasma-lens in Frankfurt, Proceedings of the 3rd EPAC Conference, Berlin, 1992). To broaden the experiences and to investigate the realisation of a LEBT concept for the HIDIF injector an experimental program using two Gabor lenses for independent variation of beam radius and envelope angel at RFQ injection was started. Therefrom the first experimental results using a double Gabor lens (DGPL) LEBT system for transporting an high perveance Xe{sup +} beam are presented and the results of numerical simulations are shown.

  10. Development of the low energy linac systems

    International Nuclear Information System (INIS)

    Cho, Yong Sub; Kwon, H. J.; Kim, Y. H.

    2005-08-01

    The project 'Development of the Low Energy Linac System' is aiming to develop the 20 MeV proton linac system. This consists of a 50 keV proton injector, a 3 MeV RFQ, and a 20 MeV DTL. We obtained the first beam signal after the 20 MeV linac. The high power switch installed in the ion source supplies the pulsed beam into the following LEBT. The pulse operation was successfully tested. The main role of the LEBT is to match the beam into the 3 MeV RFQ. The total length of the four-vane type RFQ is about 3.26m. For the field stabilization, we used the resonant coupling scheme and dipole stabilizer rods. An 1 MW klystron supplies the RF power into the RFQ. After tuning, the field deviation of the quadrupole mode is less than 2% of the design value and the dipole fraction is less than 5% of the operating mode. The following accelerating structure is DTL which accelerate 20 mA proton beams up to 20 MeV. It consists of 4 tanks and the length of each tank is less than 5 m. The lattice is FFDD type and the integrated fields of the quadrupole magnets are 1.75 T. The inner walls of the tanks are copper-plated by PR plating method. The thickness is 100m with the roughness of 0.3m. Each drift tube consists of 6 parts and assembled by e-beam welding. The tanks and drift tubes are aligned under the installation limit of 50m by using the laser-tracker. The tuning by the slug tuners and post couplers results in the field uniformity of 2% and field sensitivity of 100%/MHz. In order to detect the beam signal, we installed the Faraday cup after the RFQ or the DTL. For the RFQ, we observed the beam of 12 A under the forward RF power of 450 kW. The beam current after DTL is about 0.5 A when RF power of 150 kW was fed into each tank

  11. Low-Energy Ballistic Transfers to Lunar Halo Orbits

    Science.gov (United States)

    Parker, Jeffrey S.

    2009-01-01

    Recent lunar missions have begun to take advantage of the benefits of low-energy ballistic transfers between the Earth and the Moon rather than implementing conventional Hohmann-like lunar transfers. Both Artemis and GRAIL plan to implement low-energy lunar transfers in the next few years. This paper explores the characteristics and potential applications of many different families of low-energy ballistic lunar transfers. The transfers presented here begin from a wide variety of different orbits at the Earth and follow several different distinct pathways to the Moon. This paper characterizes these pathways to identify desirable low-energy lunar transfers for future lunar missions.

  12. A Low Energy Intelligent Clustering Protocol for Wireless Sensor Network

    DEFF Research Database (Denmark)

    Li, Qiao; Cui, Lingguo; Zhang, Baihai

    2010-01-01

    LEACH (low-energy adaptive clustering hierarchy) is a well-known self-organizing, adaptive clustering protocol of wireless sensor networks. However it has some shortcomings when it faces such problems as the cluster construction and energy management. In this paper, LEICP (low energy intelligent...

  13. Passive and low energy cooling techniques for the Czech Republic

    NARCIS (Netherlands)

    Lain, M.; Hensen, J.L.M.; Santamouris, M.

    2005-01-01

    This paper deals with the applicability of passive and low energy cooling technologies in the Czech Republic. The work includes climate analysis as well as buildings and systems analysis in order to estimate the potential of passive and low energy cooling technologies. The latter is based on case

  14. Low-energy antiprotons physics and the FLAIR facility

    International Nuclear Information System (INIS)

    Widmann, E

    2015-01-01

    FLAIR, the Facility for low-energy antiproton and ion research has been proposed in 2004 as an extension of the planned FAIR facility at Darmstadt, Germany. FLAIR was not included into the modularized start version of FAIR, but the recent installation of the CRYRING storage ring at GSI Darmstadt has opened new perspectives for physics with low-energy antiprotons at FAIR. (paper)

  15. Positron impact ionization of atomic hydrogen at low energies

    Indian Academy of Sciences (India)

    The study of low energy ionization of atomic hydrogen has undergone a rapid ... Three distinct theories for describing low energy ionization can now .... clear evidence that the backward peak for ΘЅѕ = 180° is due to positron-nucleus scat-.

  16. Low-energy-consumption hybrid lasers for silicon photonics

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Ran, Qijiang; Mørk, Jesper

    2012-01-01

    Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed.......Physics and characteristics of a hybrid vertical-cavity laser that can be an on-chip Si light source with high speed and low energy consumption are discussed....

  17. Low-energy heavy-ion reactions: Some recent developments

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1989-01-01

    We address three areas: behavior of the optical model at low energies and associated phenomena, fusion at near- and sub-barrier energies; where does fusion occur?, and recent examples of explicit coupled-channels effects at low energies. 74 refs., 18 figs

  18. Low energy dynamics of self-dual A1 strings

    International Nuclear Information System (INIS)

    Gustavsson, Andreas

    2003-01-01

    We examine the interrelation between the (2,0) supersymmetric six-dimensional effective action for the A 1 theory, and the corresponding low-energy theory for the collective coordinates associated to selfdual BPS strings. We argue that this low energy theory is a two-dimensional N=4 supersymmetric sigma model

  19. Search for solar Axion Like Particles in the low energy range at CAST

    International Nuclear Information System (INIS)

    Cantatore, G.; Karuza, M.; Lozza, V.; Raiteri, G.

    2010-01-01

    Axion Like Particles (ALPs) could be continuously produced in the Sun via the Primakoff process. The ALP flux could be seen on Earth by observing the photons produced by the ALP decay. The expected energy distribution of reconverted photons is peaked at 3 keV. There could be, however, a low energy tail due to various processes active in the Sun. We report results of the first test measurements in the low energy range performed at CAST along with a description of the experimental setup. Future detector developments are discussed and preliminary results on a liquid nitrogen cooled Avalanche Photodiode are presented.

  20. What is a low-energy house and who cares?

    Energy Technology Data Exchange (ETDEWEB)

    Litt, B.R.

    1994-12-01

    Most energy analysts view low-energy houses as good things, yet differ in their expectations of what exactly a low energy house is. There are two intertwining threads to this report. The first is an evaluation of 50 buildings that have been claimed to be low-energy residences, for which monitored energy performance data have been collected. These data represent the preliminary effort in the ongoing update of the Buildings Energy-Use Compilation and Analysis (BECA) data base for new residences. The second thread concerns the definition of a low-energy house. After the elements of a definition are presented, their implications for actors involved in providing housing are identified. Several more tractable definitions are applied to the houses in this compilation. The outcomes illustrate ways in which different interests are served by various definitions. Different definitions can yield very different energy rankings. No single definition of a low-energy house is universally applicable.

  1. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  2. Low energy nuclear reaction polyplasmon postulate

    Energy Technology Data Exchange (ETDEWEB)

    Russell, John L. [201 Heritage Drive, Apt. 208, Canton, GA 30093 (United States)], E-mail: RUSSELLJL@aol.com

    2008-11-15

    absorbed in the plasmon field by a variety of mechanisms that increase the intensity of the plasmon field and hence the rate of electron capture - that then increases the rate of nuclear reactions. This stochastic chain-reaction process continues in the grain until it is terminated by the random occurrence of losses preventing the continuation of sustaining nuclear reactions before the plasmon field decays away, or until the rise in temperature of the metal grain alters the physical properties of the metallic grain sufficiently to disrupt the polyplasmon field. Multiple reported experiments confirm that most of the nuclear energy released is absorbed by the host metallic cathode and the electrolyte. Calculations from first principles are consistent with many of the reported quantitative and qualitative phenomena.

  3. Low energy nuclear reaction polyplasmon postulate

    International Nuclear Information System (INIS)

    Russell, John L.

    2008-01-01

    field by a variety of mechanisms that increase the intensity of the plasmon field and hence the rate of electron capture - that then increases the rate of nuclear reactions. This stochastic chain-reaction process continues in the grain until it is terminated by the random occurrence of losses preventing the continuation of sustaining nuclear reactions before the plasmon field decays away, or until the rise in temperature of the metal grain alters the physical properties of the metallic grain sufficiently to disrupt the polyplasmon field. Multiple reported experiments confirm that most of the nuclear energy released is absorbed by the host metallic cathode and the electrolyte. Calculations from first principles are consistent with many of the reported quantitative and qualitative phenomena

  4. A real-time low energy electron calorimeter

    International Nuclear Information System (INIS)

    Mod Ali, N.; Smith, F.A.

    1999-01-01

    A real-time low energy electron calorimeter with a thin film window has been designed and fabricated to facilitate a reliable method of dose assessment for electron beam energies down to 200 keV. The work was initiated by the Radiation Physics Group of Queen Mary and Westfield College in collaboration with the National Physical Laboratory (NPL), Teddington. Irradiations were performed on the low and medium electron energy electron accelerators at the Malaysian Institute for Nuclear Technology Research (MINT). Calorimeter response was initially tested using the on-line temperature measurements for a 500-keV electron beam. The system was later redesigned by incorporating a data-logger to use on the self-shielded 200-keV beam. In use, the final version of the calorimeter could start logging temperature a short time before the calorimeter passed under the beam and continue measurements throughout the irradiation. Data could be easily retrieved at the end of the exposure. (author)

  5. States of low energy on Robertson-Walker spacetimes

    International Nuclear Information System (INIS)

    Olbermann, Heiner

    2007-01-01

    We construct a new class of physical states of the free Klein-Gordon field in Robertson-Walker spacetimes. This is done by minimizing the expectation value of smeared stress-energy. We get an explicit expression for the state depending on the smearing function. We call it a state of low energy. States of low energy are an improvement of the concept of adiabatic vacua on Robertson-Walker spacetimes. The latter are approximations of the former. It is shown that states of low energy are Hadamard states

  6. Low-energy effective action for the superstring

    International Nuclear Information System (INIS)

    Burgess, C.P.; Font, A.; Quevedo, F.

    1986-01-01

    We construct the low-energy D=4, N=1 supergravity that arises in superstring theories for an arbitrary number of generations. The coupling of all massless modes that carry low-energy gauge quantum numbers are calculated by truncating the heavy Kaluza-Klein modes of the ten-dimensional effective field theory. The resulting action is compared to the most general effective action compatible with the symmetries of the underlying ten-dimensional field (and string) theories. This comparison indicates which features of the truncation correctly approximate the exact low-energy action. (orig.)

  7. DCARR: a spectrograph for measuring low-energy x rays

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    DCARR, the Differential Critical Angle Reflection Refraction detector system, is described. This detector was designed to measure low-energy x rays, 500 to 5000 eV, with a high degree of resolution, 250 eV. DCARR was developed because these low-energy measurements are of interest in the diagnostics of x-radiation in nuclear tests and available equipment could not make measurements at this low an energy in field tests. DCARR is a versatile piece of equipment that can also be used as a laboratory tool, such as in measuring the low-energy x rays emitted by lasers and various x-ray machines

  8. Low-energy hadronic interactions beyond the current algebra approach

    International Nuclear Information System (INIS)

    Ivanov, A.N.; Troitskaya, N.I.; Nagy, M.

    1993-06-01

    The new low-energy AP 3 -interaction, which is produced by convergent box-constituent-quark-loop diagrams, is obtained within chiral perturbation theory at the quark level (CHPT) q with linear realization of chiral U(3) x U(3) symmetry. Its contributions to processes of low-energy interactions of low-lying mesons are investigated. The new interaction goes beyond the framework of the low-energy current algebra approach and of the effective chiral Lagrangians with linear realization of chiral symmetry, constructed at the hadronic level. (author). 17 refs, 3 figs

  9. A primer on Higgs boson low-energy theorems

    International Nuclear Information System (INIS)

    Dawson, S.; Haber, H.E.; California Univ., Santa Cruz, CA

    1989-05-01

    We give a pedagogical review of Higgs boson low-energy theorems and their applications in the study of light Higgs boson interactions with mesons and baryons. In particular, it is shown how to combine the chiral Lagrangian method with the Higgs low-energy theorems to obtain predictions for the interaction of Higgs bosons and pseudoscalar mesons. Finally, we discuss the relation between the low-energy theorems and a technique which makes use of the trace of the QCD energy-momentum tensor. 35 refs

  10. Low-energy buildings on mainstream market terms

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Elle, Morten; Hoffmann, Birgitte

    2008-01-01

    implementation of strict energy performance requirements in mainstream building. The paper describes how the municipality of Egedal experienced a collapse in regulation for low-energy buildings and what struggles it had to take on in order to convince the mainstream building industry and their customers......This paper looks into the challenge of actually implementing energy efficient technologies and concepts in mainstream new build. The aim of the paper is to point out some of the provisos of promoting low-energy buildings on mainstream market terms, emphasising the need to understand forces working...... against implementation of low-energy buildings. The study is based on actor-network theory, emphasising the relations and struggles that form the basis for pushing for low-energy buildings. The paper is based on a case study of the proactive attempt of a Danish municipality to force through an actual...

  11. Classification of low energy houses in Danish Building Regulations

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    The new Danish Building Regulations (Building Regulations, 2005) introduces the total energy consumption, i.e. energy use for heating, ventilation, cooling and domestic hot water, for buildings as a measure for the energy efficiency of new buildings, i.e. moving away from the former U-value demands....... In addition to the minimum requirements for new buildings, the new Building Regulations also specify requirements for characterizing a building as either low energy building class 1 or low energy building class 2. This paper describes a type-house that is presently being built in Denmark. The type......-house easily meets the requirements for being categorized as a low energy building class 1, and the paper investigates how much U-values can be increased if the type-house were to fulfil the requirements for a low energy building class 2 or a building that just fulfils the minimum demands....

  12. Biological assessments for the low energy demonstration accelerator, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1997-03-01

    This report discusses the biological impact to the area around the Los Alamos National Laboratory of the Low Energy Demonstration Accelerator. In particular the impact to the soils, water quality, vegetation, and wildlife are discussed.

  13. Low-energy nuclear reactions with double-solenoid- based ...

    Indian Academy of Sciences (India)

    solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

  14. Low energy effective Lagrangians in open superstring theory

    International Nuclear Information System (INIS)

    Medina, Ricardo

    2008-01-01

    The low energy effective Lagrangian describes the interactions of the massless modes of String Theory. Present work is being done to obtain all alpha' 3 terms (bosonic and fermionic) by means of the known 5-point amplitudes and SUSY

  15. Bag-model quantum chromodynamics for hyperons at low energy

    International Nuclear Information System (INIS)

    Weber, H.J.; Maslow, J.N.

    1980-01-01

    In a non-perturbative bag model framework, gluon exchange which mediates quark exchange scattering in conjunction with quark interchange is shown to be the basis of the OBE interactions of hyperons at low energy. (orig.)

  16. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The Ward identities of current algebra are combined with gauge invariance constraints, on-shell PCAC and the Bjorken limit to obtain the low-energy expressions of the pion photo- and electroproduction invariant amplitudes for physical pions

  17. Surface Passivation and Junction Formation Using Low Energy Hydrogen Implants

    Science.gov (United States)

    Fonash, S. J.

    1985-01-01

    New applications for high current, low energy hydrogen ion implants on single crystal and polycrystal silicon grain boundaries are discussed. The effects of low energy hydrogen ion beams on crystalline Si surfaces are considered. The effect of these beams on bulk defects in crystalline Si is addressed. Specific applications of H+ implants to crystalline Si processing are discussed. In all of the situations reported on, the hydrogen beams were produced using a high current Kaufman ion source.

  18. Low-energy limit of two-scale field theories

    International Nuclear Information System (INIS)

    Leon, J.; Perez-Mercader, J.; Sanchez, M.F.

    1991-01-01

    We present a full and self-contained discussion of the decoupling theorem applied to several general models in four-dimensional field theory. We compute in each case the low-energy effective action and show the explicit one-loop expressions for each of the effective parameters. We find that for suitable conditions one can always build an effective low-energy theory where the conditions of the decoupling theorem are satisfied

  19. Space charge and working point studies in the CERN Low Energy Ion Ring

    CERN Document Server

    Huschauer, A; Hancock, S; Kain, V

    2017-01-01

    The Low Energy Ion Ring (LEIR) is at the heart ofCERN’s heavy ion physics programme and was designed toprovide the high phase space densities required by the exper-iments at the Large Hadron Collider (LHC). LEIR is the firstsynchrotron of the LHC ion injector chain and it receives aquasi-continuous pulse of lead ions (Pb54+) from Linac3, ex-ploiting a sophisticated multi-turn injection scheme in bothtransverse and longitudinal planes. Seven of these pulses areinjected and accumulated, which requires continuous elec-tron cooling (EC) at low energy to decrease the phase spacevolume of the circulating beam in between two injections.Subsequently, the coasting beam is adiabatically capturedin two bunches, which are then accelerated and extractedtowards the Proton Synchrotron (PS). Figure 1 shows theLEIR magnetic cycle and the different steps required forbeam production.

  20. Energy analyzer for Auger electron spectroscopy and low-energy backscattering ion spectroscopy

    International Nuclear Information System (INIS)

    Volkov, S.S.; Gorelik, V.A.; Gutenko, V.T.; Protopopov, O.D.; Trubitsin, A.A.; Shuvalova, Z.A.; Yakushev, G.A.

    1988-01-01

    Energy analyzer for electron Auger spectroscopy and low-energy backscattering ion spectroscopy is described. Analyzer presents one-cascade variant of cylindrical mirror with second-order focusing. Energy relative resolution is continuously adjusted within 0.2-1.2% limits. Signal/noise relation by Cu Auger-line at 1 muA current of exciting beam changes upper limit of range 150-450

  1. Internal defibrillation: pain perception of low energy shocks.

    Science.gov (United States)

    Steinhaus, David M; Cardinal, Debbie S; Mongeon, Luc; Musley, Shailesh Kumar; Foley, Laura; Corrigan, Susie

    2002-07-01

    Recently, device-based low energy cardoversion shocks have been used as therapy for AF. However, discomfort from internal low energy electrical shocks is poorly understood. The aim of this study was to evaluate pain perception with low energy internal discharges. Eighteen patients with ICD devices for malignant ventricular arrhythmias were recruited to receive shocks of 0.4 and 2 J in the nonsedated state. Discharges were delivered in a blinded, random order and questionnaires were used to determine discomfort levels and tolerability. Patients perceived discharges at these energies as relatively uncomfortable, averaging a score of 7.3 on a discomfort scale of 0-10, and could not distinguish 0.4-J shocks from 2-J shocks. Second shocks were perceived as more uncomfortable than initial discharges, regardless of the order in which the shocks were delivered. Despite the perceived discomfort, 83% of patients stated that they would tolerate discharges of this magnitude once per month, and 44% would tolerate weekly discharges. Patients perceive low energy discharges as painful and cannot distinguish between shocks of 0.4 and 2 J. The results suggest that ICD systems developed to treat atrial tachyarrhythmias should minimize the number of shocks delivered to terminate an atrial tachyarrhythmia episode. The majority of the patients tolerated low energy shocks provided the discharges are infrequent (once per month).

  2. Coulomb effects in low-energy nuclear fragmentation

    Science.gov (United States)

    Wilson, John W.; Chun, Sang Y.; Badavi, Francis F.; John, Sarah

    1993-01-01

    Early versions of the Langley nuclear fragmentation code NUCFRAG (and a publicly released version called HZEFRG1) assumed straight-line trajectories throughout the interaction. As a consequence, NUCFRAG and HZEFRG1 give unrealistic cross sections for large mass removal from the projectile and target at low energies. A correction for the distortion of the trajectory by the nuclear Coulomb fields is used to derive fragmentation cross sections. A simple energy-loss term is applied to estimate the energy downshifts that greatly alter the Coulomb trajectory at low energy. The results, which are far more realistic than prior versions of the code, should provide the data base for future transport calculations. The systematic behavior of charge-removal cross sections compares favorably with results from low-energy experiments.

  3. European national strategies to move towards very low energy buildings

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Thomsen, Kirsten Engelund

    high energy performance. It is important to stress the need for MS to introduce a national or regional definition of very low energy buildings in their building regulation and to develop a national strategy towards this level of energy performance to become the standard. This market transformation...... the ambition in the EU Action plan - to develop an EU strategy towards very low energy houses. The current recast of the EPBD is an opportunity, which must not be missed to introduce the requirement to MS to define very low energy buildings and a national strategy towards this level of energy performance....... A strategy for improved energy efficiency of existing buildings is a necessity if the energy consumption is to be reduced significantly over a limited period of time. The life time of buildings ranges from 50 to 100 years and improvement of the existing building stock will thus have much higher impact than...

  4. Coulomb and Nuclear Breakup at Low Energies: Scaling Laws

    Directory of Open Access Journals (Sweden)

    Hussein M. S.

    2013-12-01

    Full Text Available We report on a recent work on the low-energy behavior of the breakup cross section in so far as it has important role in the fusion of weakly bound and halo nuclei at near-barrier energies. We assess the way the nuclear component of this cross section scales with the target mass. In complete accord with previous finding at higher energies we verify that the low energy behavior of the breakup cross section for a given projectile and relative center of mass energy with respect to the Coulomb barrier height scales as the cubic root of the mass number of the target. Surprisingly we find that the Coulomb component of the breakup cross section at these low energies also obeys scaling, but with a linear dependence on the target charge. Our findings are important when planning for experiments involving these exotic nuclei.

  5. Low-energy limit of the extended Linear Sigma Model

    Energy Technology Data Exchange (ETDEWEB)

    Divotgey, Florian [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Kovacs, Peter [Wigner Research Center for Physics, Hungarian Academy of Sciences, Institute for Particle and Nuclear Physics, Budapest (Hungary); GSI Helmholtzzentrum fuer Schwerionenforschung, ExtreMe Matter Institute, Darmstadt (Germany); Giacosa, Francesco [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); Jan-Kochanowski University, Institute of Physics, Kielce (Poland); Rischke, Dirk H. [Johann Wolfgang Goethe-Universitaet, Institut fuer Theoretische Physik, Frankfurt am Main (Germany); University of Science and Technology of China, Interdisciplinary Center for Theoretical Study and Department of Modern Physics, Hefei, Anhui (China)

    2018-01-15

    The extended Linear Sigma Model is an effective hadronic model based on the linear realization of chiral symmetry SU(N{sub f}){sub L} x SU(N{sub f}){sub R}, with (pseudo)scalar and (axial-)vector mesons as degrees of freedom. In this paper, we study the low-energy limit of the extended Linear Sigma Model (eLSM) for N{sub f} = flavors by integrating out all fields except for the pions, the (pseudo-)Nambu-Goldstone bosons of chiral symmetry breaking. The resulting low-energy effective action is identical to Chiral Perturbation Theory (ChPT) after choosing a representative for the coset space generated by chiral symmetry breaking and expanding it in powers of (derivatives of) the pion fields. The tree-level values of the coupling constants of the effective low-energy action agree remarkably well with those of ChPT. (orig.)

  6. Low-energy physics of high-temperature superconductors

    International Nuclear Information System (INIS)

    Emery, V.J.; Kivelson, S.A.

    1992-01-01

    It is argued that the low-energy properties of high temperature superconductors are dominated by the interaction between the mobile holes and a particular class of collective modes, corresponding to local large-amplitude low-energy fluctuations in the hole density. The latter are a consequence of the competition between the effects of long-range Coulomb interactions and the tendency of a low concentration of holes in an antiferromagnet to phase separate. The low-energy behavior of the system is governed by the same fixed point as the two-channel Kondo problem, which accounts for the ''universality'' of the properties of the cuprate superconductors. Predictions of the optical properties and the spin dynamics are compared with experiment. The pairing resonance of the two Kondo problem gives a mechanism of high temperature superconductivity with an unconventional symmetry of the order parameter

  7. Electric and Magnetic Dipole Strength at Low Energy

    Science.gov (United States)

    Sieja, K.

    2017-08-01

    A low-energy enhancement of radiative strength functions was deduced from recent experiments in several mass regions of nuclei, which is believed to impact considerably the calculated neutron capture rates. In this Letter we investigate the behavior of the low-energy γ -ray strength of the Sc 44 isotope, for the first time taking into account both electric and magnetic dipole contributions obtained coherently in the same theoretical approach. The calculations are performed using the large-scale shell-model framework in a full 1 ℏω s d -p f -g d s model space. Our results corroborate previous theoretical findings for the low-energy enhancement of the M 1 strength but show quite different behavior for the E 1 strength.

  8. Electron polarimetry at low energies in Hall C at JLab

    International Nuclear Information System (INIS)

    Gaskell, D.

    2013-01-01

    Although the majority of Jefferson Lab experiments require multi-GeV electron beams, there have been a few opportunities to make electron beam polarization measurements at rather low energies. This proceedings will discuss some of the practical difficulties encountered in performing electron polarimetry via Mo/ller scattering at energies on the order of a few hundred MeV. Prospects for Compton polarimetry at very low energies will also be discussed. While Mo/ller scattering is likely the preferred method for electron polarimetry at energies below 500 MeV, there are certain aspects of the polarimeter and experiment design that must be carefully considered

  9. A facility for low energy charged particle induced reaction studies

    International Nuclear Information System (INIS)

    Vilaithong, T.; Singkarat, S.; Yu, L.D.; Intarasiri, S.; Tippawan, U.

    2000-01-01

    In Chiang Mai, a highly stable low energy ion accelerator (0 - 350 kV) facility is being established. A subnano-second pulsing system will be incorporated into the beam transport line. The detecting system will consist of a time-of-flight charged particle spectrometer and a high resolution gamma-ray system. The new facility will be used in the studies of low energy heavy ion backscattering and charged particle induced cross section measurement in the interests of material characterization and nucleosynthesis. (author)

  10. Scattering of polarized low-energy electrons by ferromagnetic metals

    International Nuclear Information System (INIS)

    Helman, J.S.

    1981-01-01

    A source of spin polarized electrons with remarkable characteristics based on negative electron affinity (NEA) GaAs has recently been developed. It constitutes a unique tool to investigate spin dependent interactions in electron scattering processes. The characteristics and working principles of the source are briefly described. Some theoretical aspects of the scattering of polarized low-energy electrons by ferromagnetic metals are discussed. Finally, the results of the first polarized low-energy electron diffraction experiment using the NEA GaAs source are reviewed; they give information about the surface magnetization of ferromagnetic Ni (110). (Author) [pt

  11. Very low energy scanning electron microscopy in nanotechnology

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Hovorka, Miloš; Mika, Filip; Mikmeková, Eliška; Mikmeková, Šárka; Pokorná, Zuzana; Frank, Luděk

    2012-01-01

    Roč. 9, 8/9 (2012), s. 695-716 ISSN 1475-7435 R&D Projects: GA MŠk OE08012; GA MŠk ED0017/01/01; GA AV ČR IAA100650902 Institutional research plan: CEZ:AV0Z20650511 Keywords : scanning electron microscopy * very low energy electrons * cathode lens * grain contrast * strain contrast * imaging of participates * dopant contrast * very low energy STEM * graphene Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.087, year: 2012

  12. Obervations of low energy magnetospheric plasma outside the plasmasphere

    International Nuclear Information System (INIS)

    Hultqvist, B.

    1985-01-01

    After some introductory discussions about morphological concepts and limitations of various measurement techniques, existing low energy plasma data, orginating primarily from the GEOS, Dynamics Explorer, and Prognoz spacecraft, is described and discussed. The plasmasphere measurements are not included (but for some observations of plasmasphere refilling). It is finally concluded that we are very far from a complete picture of the low-energy plasma component in the magnetosphere and that this problem has to be given high priority in planning payloads of future space plasma physics missions. (Author)

  13. Progress on a spherical TPC for low energy neutrino detection

    International Nuclear Information System (INIS)

    Aune, S; Colas, P; Deschamps, H; Dolbeau, J; Fanourakis, G; Ribas, E Ferrer; Enqvist, T; Geralis, T; Giomataris, Y; Gorodetzky, P; Gounaris, G J; Gros, M; Irastorza, I G; Kousouris, K; Lepeltier, V; Morales, J; Patzak, T; Paschos, E A; Salin, P; Savvidis, I; Vergados, J D

    2006-01-01

    The new concept of the spherical TPC aims at relatively large target masses with low threshold and background, keeping an extremely simple and robust operation. Such a device would open the way to detect the neutrino-nucleus interaction, which, although a standard process, remains undetected due to the low energy of the neutrino-induced nuclear recoils. The progress in the development of the first 1 m 3 prototype at Saclay is presented. Other physics goals of such a device could include supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino, among others

  14. Universality in low energy three-body systems

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Tomio, L; Frederico, T.

    1997-01-01

    The renormalizability of the quantum theory of non-relativistic three-body system with zero range interaction, warranties that all the low-energy three-body properties are well defined and the low-energy two-body and only one three-body physical information are known. Considering this observation, we have shown that the conditions for the occurrence of Efimov states can be easily reached with any model of short range potential where the three-body ground state and the corresponding binding energy of the subsystems are kept fixed. This approach was applied to the recently discovered halo nuclei. (author)

  15. Ultra-low-energy wide electron exposure unit

    International Nuclear Information System (INIS)

    Yonago, Akinobu; Oono, Yukihiko; Tokunaga, Kazutoshi; Kishimoto, Junichi; Wakamoto, Ikuo

    2001-01-01

    Heat and ultraviolet ray processes are used in surface dryness of paint, surface treatment of construction materials and surface sterilization of food containers. A process using a low-energy wide-area electron beam (EB) has been developed that features high speed and low drive cost. EB processing is not widespread in general industry, however, due to high equipment cost and difficult maintenance. We developed an ultra-low-energy wide-area electron beam exposure unit, the Mitsubishi Wide Electron Exposure Unit (MIWEL) to solve these problems. (author)

  16. Track structure for low energy ions including charge exchange processes

    International Nuclear Information System (INIS)

    Uehara, S.; Nikjoo, H.

    2002-01-01

    The model and development is described of a new generation of Monte Carlo track structure codes. The code LEAHIST simulates full slowing down of low-energy proton history tracks in the range 1 keV-1 MeV and the code LEAHIST simulates low-energy alpha particle history tracks in the range 1 keV-8 MeV in water. All primary ion interactions are followed down to 1 keV and all electrons to 1 eV. Tracks of secondary electrons ejected by ions were traced using the electron code KURBUC. Microdosimetric parameters derived by analysis of generated tracks are presented. (author)

  17. Occupant Experiences and Satisfaction with New Low-Energy Houses

    DEFF Research Database (Denmark)

    Knudsen, Henrik Nellemose; Thomsen, Kirsten Engelund; Mørck, Ove

    2013-01-01

    -energy houses that meet the future lower energy requirements of the planned Danish Building Regulations 2015. The purpose was to study experiences and satisfaction among occupants living in new low-energy houses. It included i.a. overall satisfaction, perceived indoor climate and experiences and satisfaction...... be addressed in order to make low-energy houses attractive to ordinary people. Occupants experienced among other things noise from the technical installations and that it was too hot in summer and too cold in winter, that there were a series of problems with the technical installations and that their use...

  18. Calculation of low-energy reactor neutrino spectra reactor for reactor neutrino experiments

    Energy Technology Data Exchange (ETDEWEB)

    Riyana, Eka Sapta; Suda, Shoya; Ishibashi, Kenji; Matsuura, Hideaki [Dept. of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Kyushu (Japan); Katakura, Junichi [Dept. of Nuclear System Safety Engineering, Nagaoka University of Technology, Nagaoka (Japan)

    2016-06-15

    Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% {sup 235}U contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. {sup 241}Pu) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate. Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.

  19. Charge-coupled device area detector for low energy electrons

    Czech Academy of Sciences Publication Activity Database

    Horáček, Miroslav

    2003-01-01

    Roč. 74, č. 7 (2003), s. 3379 - 3384 ISSN 0034-6748 R&D Projects: GA ČR GA102/00/P001 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy electrons * charged-coupled device * detector Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.343, year: 2003

  20. Utilization of low-energy electron accelerators in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2003-02-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  1. Corrosion behavior of low energy, high temperature nitrogen ion ...

    Indian Academy of Sciences (India)

    Corrosion behavior of low energy, high temperature nitrogen ion-implanted AISI 304 stainless steel. M GHORANNEVISS1, A SHOKOUHY1,∗, M M LARIJANI1,2,. S H HAJI HOSSEINI 1, M YARI1, A ANVARI4, M GHOLIPUR SHAHRAKI1,3,. A H SARI1 and M R HANTEHZADEH1. 1Plasma Physics Research Center, Science ...

  2. Acceleration of low energy charged particles by gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Voyatzis, G. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)]. E-mail: voyatzis@auth.gr; Vlahos, L. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Ichtiaroglou, S. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Papadopoulos, D. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)

    2006-04-03

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

  3. Acceleration of low energy charged particles by gravitational waves

    International Nuclear Information System (INIS)

    Voyatzis, G.; Vlahos, L.; Ichtiaroglou, S.; Papadopoulos, D.

    2006-01-01

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state

  4. Low energy supersymmetric models for several generations and proton decay

    International Nuclear Information System (INIS)

    Deo, B.B.; Sarkar, U.

    1983-08-01

    It is found that by invoking additional horizontal gauge symmetries required to explain the generational structure the low energy standard supersymmetric unified theories avoid the renormalizable unsuppressed baryon number violating interactions in a natural way. Theories considered here are anomaly-free by construction. (author)

  5. Low energy house in existing buildings; Niedrigenergiehaus im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Sahner, G. [BDA, Stuttgart/Augsburg (Germany)

    2008-07-01

    Presented is an energetic sanitation of residential units in the frame of a German pilot program (''low energy houses in the existing building sector'') initiated by the ministry of traffic, civil engineering and city development. (GL)

  6. Chiral symmetry and nucleon structure: Low energy aspects

    International Nuclear Information System (INIS)

    Weise, W.

    1989-01-01

    The symmetries and currents of QCD at low energy and long wavelength are realized in the form of mesons, rather than quarks and gluons. In this talk I summarize the merits, but also the limits, of chiral non-linear meson theories and their soliton solutions, in descriptions of nucleon structure and the nucleon-nucleon interaction. (orig.)

  7. Low-energy cosmic rays in the Orion region

    DEFF Research Database (Denmark)

    Pohl, M.

    1998-01-01

    The recently observed nuclear gamma-ray line emission from the Orion complex implies a high flux of low-energy cosmic rays (LECR) with unusual abundance. This cosmic ray component would dominate the energy density, pressure, and ionising power of cosmic rays, and thus would have a strong impact...

  8. Overview of the low energy accelerator scanning system

    International Nuclear Information System (INIS)

    Leo Kwee Wah; Lojius Lombigit; Muhamad Zahidee Taat; Abu Bakar Ghazali; Mohd Rizal Ibrahim; Mohd Rizal Chulan Md Chulan; Azaman Ahmad; Abdul Halim Baijan; Rokiah Mohd Sabri

    2009-01-01

    This paper describes the specification of the low energy accelerator (Baby-EBM; Electron Beam Machine) scanning system. It comprises a discussion of coil inductance measurement, power supply design and the test results. The scanning horn system was completely assembled and tested; it was found that the system is able to scan the beam across the scanning window with a required beam profile. (Author)

  9. Low-energy nuclear reactions with double-solenoid

    Indian Academy of Sciences (India)

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems ...

  10. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  11. MEIC Proton Beam Formation with a Low Energy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  12. Low-energy properties of fractional helical Luttinger liquids

    NARCIS (Netherlands)

    Meng, T.; Fritz, L.|info:eu-repo/dai/nl/371569559; Schuricht, D.|info:eu-repo/dai/nl/369284690; Loss, D.

    2014-01-01

    We investigate the low-energy properties of (quasi) helical and fractional helical Luttinger liquids. In particular, we calculate the Drude peak of the optical conductivity, the density of states, as well as charge transport properties of the interacting system with and without attached Fermi liquid

  13. Utilization of low-energy electron accelerators in Korea

    International Nuclear Information System (INIS)

    Lee, Byung Cheol

    2003-01-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  14. Elastic scattering of low energy γ-rays

    International Nuclear Information System (INIS)

    Whittingham, I.B.

    1978-01-01

    The current status of the theory of the elastic scattering of low energy γ rays is reviewed and a detailed analysis of the theoretical background to the recent calculation of Rayleigh scattering by W.R.Johnson and co-workers is presented

  15. Characterization of low energy radioactive beams using direct reactions

    DEFF Research Database (Denmark)

    Johansen, J.G.; Fraser, M.A.; Bildstein, V.

    2013-01-01

    We demonstrate a new technique to determine the beam structure of low energy radioactive beams using coincidence events from a direct reaction. The technique will be described and tested using Geant4 simulations. We use the technique to determine for the first time the width, divergence and energy...

  16. Low-energy positron beams - origins, developments and applications

    International Nuclear Information System (INIS)

    Beling, C.D.; Charlton, M.

    1987-01-01

    Over the last 15 years there have been rapid advances in the technology associated with low-energy positron beams. The origins of these advances, and some of the major developments, are discussed. Some applications from the diverse fields of surface physics, atomic scattering and positronium studies are highlighted. (author)

  17. Performance of the Low-energy House in Sisimiut

    DEFF Research Database (Denmark)

    Rode, Carsten; Kragh, Jesper; Borchersen, Egil

    2009-01-01

    A low-energy house was built in Sisimiut, Greenland in 2004-05 and since its inauguration in April 2005, its performance and operation have been object of study for researchers and students. The house is characterised by a highly insulated building envelope, advanced windows and a ventilation sys...

  18. QCD at low energy: a many-body approach

    International Nuclear Information System (INIS)

    Yépez-Martínez, T; Hess, P O; Lerma, S; Szczepaniak, A; Civitarese, O

    2011-01-01

    A review is given on recent results in the treatment of an arbitrary number of orbital levels in low energy QCD. For the pure quark part, analytic results for the dominant part of the Hamiltonian are presented. Possible extensions, including dynamic gluons, are discussed.

  19. Layout of the LER [Low Energy Ring] Arc

    International Nuclear Information System (INIS)

    Hutton, A.

    1990-01-01

    We have recently been trying to accumulate all of the information necessary to decide on the layout of the regular curved arcs of the Low Energy Ring (LER) and there have been several ABC Notes published on different aspects of the problem. This note will describe the layout that has been derived from these considerations

  20. Low energy quasi free scattering on nuclear surface

    Energy Technology Data Exchange (ETDEWEB)

    Shiyuan, S.

    1983-05-01

    The result of RGM calculation of low energy /sup 3/He(n, n)/sup 3/ He total elastic cross section does not agree well with experimental data for E/sub n/<1 MeV. This discrepancy can be improved by assuming lwo energy quasi-free scattering of particles beyond the nuclear surface.

  1. Working group report: Low energy and flavour physics

    Indian Academy of Sciences (India)

    This is a report of the low energy and flavour physics working group at ... that calculates the non-leptonic decay amplitudes including the long-distance con- tributions. There were three lectures that lasted for over seven hours, and were.

  2. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

  3. Low energy p anti p strong interactions: theoretical perspective

    International Nuclear Information System (INIS)

    Dover, C.B.

    1985-01-01

    Several of the frontier problems in low energy nucleon-antinucleon phenomenology are addressed. Spin observables and dynamical selection rules in N anti N annihilation are used as examples of phenomena which offer particularly strong constraints on theoretical models, formulated either in terms of meson and baryon exchange or as effective operators in a non-perturbative quark-gluon picture. 24 refs

  4. Low-energy nuclear fission and our understanding of the nucleus

    International Nuclear Information System (INIS)

    Hall, H.L.; Hoffman, D.C.

    1990-01-01

    The interactions between experimental discoveries in low-energy nuclear fission and the theoretical understanding of the structure of the nucleus are reviewed. The history of this synergistic relationship begins with the discovery of fission, the development of the liquid-drop model and the experimental evidence for magic numbers, continues through the development of the shell model, the experimental discovery of shape isomerism, the double-humped fission barrier the spontaneous fission half-life disaster, the discovery of symmetric mass division in spontaneous fission and theoretical treatments based on different paths to scission. It concludes with a brief review of current experimental and theoretical understanding of low-energy fission and the prospects for future developments. (author) 150 refs.; 5 figs.; 1 tab

  5. Low energy houses and passive houses - common questions; Laagenergihus och passivhus - vanliga fraagestaellningar

    Energy Technology Data Exchange (ETDEWEB)

    Sikander, Eva; Samuelson, Ingemar; Gustavsson, Thorbjoern; Ruud, Svein; Larsson, Krister; Hiller, Carolina; Werner, Goesta; Gabrielii, Kristina

    2009-07-01

    This feasibility study of passive houses and low-energy houses has raised several questions concerning aspects of which more knowledge is needed. Many can be answered by existing knowledge, but there are still several that can only partly be answered, and some that cannot be answered at all. As there is a substantial demand for, and interest in, the construction of low-energy houses and passive houses, it is important that the remaining questions should be addressed so that the building sector can continue to develop. Examples of areas where further knowledge is needed include: moisture safe and energy-efficient building envelopes; demand-responsive ventilation, without risk of poor indoor environmental conditions; thermal comfort (summer and winter); airtight and durable detailing; design systems and working methods to ensure retention of good characteristics when converting or extending buildings; durability aspects of certain components and functions; the effects of occupants on energy use; how indoor environment conditions and functions will cope with climate change; quality assurance in order to ensure that the appropriate knowledge is applied, and that the work is carried out properly. Some important points to emphasise: The design and construction of low-energy houses and passive houses must be firmly based on the correct design principles and appropriate standards of workmanship, in order to ensure that the houses are energy-efficient, have good indoor environmental conditions and can be expected to have long lives. Proper understanding of the principles, coupled with constant quality awareness, are essential in all stages of the work from the developer, designer and construction personnel but also during operation-phase. Hitherto, low-energy houses and passive houses have been built in relatively small numbers, but the expectation is that interest in them will increase. This raises the question of how, if production is to be very much more than at present

  6. Radiation processing of liquid with low energy electron accelerator

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2003-01-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

  7. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  8. Utilization of bio-resources by low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2003-01-01

    Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  9. Emittance measurements in low energy ion storage rings

    Science.gov (United States)

    Hunt, J. R.; Carli, C.; Resta-López, J.; Welsch, C. P.

    2018-07-01

    The development of the next generation of ultra-low energy antiproton and ion facilities requires precise information about the beam emittance to guarantee optimum performance. In the Extra-Low ENergy Antiproton storage ring (ELENA) the transverse emittances will be measured by scraping. However, this diagnostic measurement faces several challenges: non-zero dispersion, non-Gaussian beam distributions due to effects of the electron cooler and various systematic errors such as closed orbit offsets and inaccurate rms momentum spread estimation. In addition, diffusion processes, such as intra-beam scattering might lead to emittance overestimates. Here, we present algorithms to efficiently address the emittance reconstruction in presence of the above effects, and present simulation results for the case of ELENA.

  10. Low-energy restoration of parity and maximal symmetry

    International Nuclear Information System (INIS)

    Raychaudhuri, A.; Sarkar, U.

    1982-01-01

    The maximal symmetry of fermions of one generation, SU(16), which includes the left-right-symmetric Pati-Salam group, SU(4)/sub c/ x SU(2) /sub L/ x SU(2)/sub R/, as a subgroup, allows the possibility of a low-energy (M/sub R/approx.100 GeV) breaking of the left-right symmetry. It is known that such a low-energy restoration of parity can be consistent with weak-interaction phenomenology. We examine different chains of descent of SU(16) that admit a low value of M/sub R/ and determine the other intermediate symmetry-breaking mass scales associated with each of these chains. These additional mass scales provide an alternative to the ''great desert'' expected in some grand unifying models. The contributions of the Higgs fields in the renormalization-group equations are retained and are found to be important

  11. Experimental nuclear physics research challenges at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E.; Morales G, L. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Murillo O, G. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2010-02-15

    Experimental research with low energy beams of ions (a few MeV) in nuclear physics has gone through a phase transition along its evolution in fifty years because of the increasing complexity (and cost) of the equipment required to conduct meaningful investigations. Many of the small cyclotrons and Van de Graaff (single ended and tandem) accelerators have been used for the last three decades mostly in applications related to the characterization and modification of materials. Specific experimental investigations in nuclear physics with low energy accelerators are proposed in this work. Specifically we discuss the topic of nuclear radii measurements of radioactive species produced via (d,n) reactions. Some emphasis is given to the instrumentation required. (Author)

  12. Si etching with reactive neutral beams of very low energy

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Yasuhiro [Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-chou, Suita, Osaka 565-0871 (Japan); Hamagaki, Manabu; Mise, Takaya [RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan); Iwata, Naotaka; Hara, Tamio [Toyota Technological Institute, 2-12-1 Hisakata, Tenpaku-ku, Nagoya 468-8511 (Japan)

    2014-12-14

    A Si etching process has been investigated with reactive neutral beams (NBs) extracted using a low acceleration voltage of less than 100 V from CF{sub 4} and Ar mixed plasmas. The etched Si profile shows that the etching process is predominantly anisotropic. The reactive NB has a constant Si etching rate in the acceleration voltage range from 20 V to 80 V. It is considered that low-energy NBs can trigger Si etching because F radicals adsorb onto the Si surface and weaken Si–Si bonds. The etching rate per unit beam flux is 33 times higher than that with Ar NB. These results show that the low-energy reactive NB is useful for damage-free high speed Si etching.

  13. Diagnosis and dynamics of low energy electron beams using DIADYN

    International Nuclear Information System (INIS)

    Marghitu, S.; Oproiu, C.; Toader, D.; Ruset, C.; Grigore, E.; Marghitu, O.; Vasiliu, M.

    2008-01-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  14. Diagnosis and dynamics of low energy electron beams using DIADYN

    Energy Technology Data Exchange (ETDEWEB)

    Marghitu, S [Electrostatica, ICPE-CA S.A., Spaiul Unirii 313, Sector 3, RO-74204 Bucharest (Romania); Oproiu, C; Toader, D; Ruset, C; Grigore, E [National Institute for Laser, Plasma and Radiation Physics, PO Box MG-36, 409 Atomistilor Street, RO-76900 Bucharest-Magurele (Romania); Marghitu, O [Institute for Space Sciences, INCDLPFR, PO Box MG-23, RO-76911 Bucharest-Magurele (Romania); Vasiliu, M [Politehnica University, 313 Splaiul Independentei, RO-060032, Bucharest (Romania)

    2008-07-01

    The paper presents original results concerning electron beam diagnosis and dynamics using DIADYN, a low energy (10 - 50 kV), medium intensity (0.1 - 1 A) laboratory equipment. A key stage in the operation of DIADYN is the beam diagnosis, performed by the non-destructive, modified three-gradient method (MTGM). We concentrate on the better use of experimental and computational techniques, in order to improve the consistency of the results. At present, DIADYN is equipped with a hot filament vacuum electron source (VES), consisting of a convergent Pierce diode, working in a pulse mode. Since the plasma electron sources (PES) have a longer lifetime and produce higher beam currents, we discuss the possibility to replace the VES with a PES. Special attention is given to VES results in a functioning regime typical for a low energy glow discharge PES. (authors)

  15. Low-energy proton increases associated with interplanetary shock waves.

    Science.gov (United States)

    Palmeira, R. A. R.; Allum, F. R.; Rao, U. R.

    1971-01-01

    Impulsive increases in the low energy proton flux observed by the Explorer 34 satellite, in very close time association with geomagnetic storm sudden commencements are described. It is shown that these events are of short duration (20-30 min) and occur only during the decay phase of a solar cosmic-ray flare event. The differential energy spectrum and the angular distribution of the direction of arrival of the particles are discussed. Two similar increases observed far away from the earth by the Pioneer 7 and 8 deep-space probes are also presented. These impulsive increases are compared with Energetic Storm Particle events and their similarities and differences are discussed. A model is suggested to explain these increases, based on the sweeping and trapping of low energy cosmic rays of solar origin by the advancing shock front responsible for the sudden commencement detected on the earth.

  16. Energy performance of the low-energy house in Greenland

    DEFF Research Database (Denmark)

    Kragh, Jesper; Svendsen, Svend

    2005-01-01

    by ventilation heat recovery (90% efficiency) specially designed for arctic conditions, by using thicker insulation in walls (300 mm) and roof/floor (350 mm), and by using solar hot water heating (3250 kWh/year). The building is intended to enhance sustainability in the building sector in Greenland....... energy gain, efficient ventilation system with heat recovery and solar heating. In this paper the results of a calculation of the energy consumption of low-energy house is presented. The calculation was done using the program BSim2002 [1] and a new weather test reference year based on climatic data......The object of the low-energy house in Sisimiut in Greenland was to build a house with an energy consumption less than 80 kWh/m² corresponding to half the energy frame of the coming building code. Therefore the focus in this project has been on large insulation thicknesses, windows with high net...

  17. Revealing low-energy part of the beta spectra

    International Nuclear Information System (INIS)

    Selvi, S.; Celiktas, C.

    2002-01-01

    An effective method is proposed to separate electronic noise from the beta-particle spectra revealing lower energy part of the spectra. The available methods for reducing the noise problem cut the noise along with the low-energy part of the beta spectra by using a discriminator. Our setup eliminates this undesirable effect by shifting the noise toward the lowest energy scale leaving the low-energy part of spectra undisturbed. We achieved this noise-pulse-separation by treating the noise as a pulse so that we can exploit the application of the pulse-shape analyzer equipment used for pulse shape identification of particles and rejection of defective pulses. To the best of our knowledge this method of the noise separation is a novel approach

  18. Challenges in validating radiation sterilization with low energy electron irradiation

    International Nuclear Information System (INIS)

    Miller, A.; Helt-Hansen, J.

    2011-01-01

    Complete text of publication follows. Low energy electron irradiation (80-300 keV) is used increasingly for sterilization or decontamination in connection with isolators for aseptic filling lines in the pharmaceutical industry. It is not defined how validation for this process shall be carried out. A method can be derived from the medical device standard for radiation sterilization, ISO 11137, because the principles described in this standard can be applied to almost any industrial irradiation process. The validations elements are: Process definition, concerning specification of the dose required for the process and the maximum acceptable dose for the product. Installation qualification, concerning acceptance the irradiation facility. Operational qualification, concerning characterization of the facility. Performance qualification, concerning setting up the process. Process control, concerning routine monitoring. The limited penetration of the low energy electrons leads to problems with respect to executing these validation steps. This paper discusses these problems, and shows with examples how they can be solved.

  19. Consumer Unit for Low Energy District Heating Net

    DEFF Research Database (Denmark)

    Paulsen, Otto; Fan, Jianhua; Furbo, Simon

    2008-01-01

    to reduce heat loss in the network. The consumer’s installation is a unit type with an accumulation tank for smoothing the heat load related to the domestic hot water. The building heat load is delivered by an under-floor heating system. The heavy under-floor heating system is assumed to smooth the room...... heat load on a daily basis, having a flow temperature control based on outdoor climate. The unit is designed for a near constant district heating water flow. The paper describes two concepts. The analyses are based on TRNSYS (Klein et al., 2006) simulation, supplied with laboratory verification......A low energy/ low temperature consumer installation is designed and analyzed. The consumer type is a low energy single family house 145 m2 with annual energy consumption in the range of 7000 kWh, incl. domestic hot water in a 2800 degree day climate. The network is an extreme low temperature system...

  20. Low-energy neutral current phenomenology and grand unified theories

    International Nuclear Information System (INIS)

    Del Aguila, F.; Mendez, A.

    1981-01-01

    We derive necessary and sufficient conditions to be satisfied by any expanded electroweak gauge model in order to reproduce the standard model low-energy neutral current predictions. These conditions imply several constraints on the neutral gauge boson masses and the quantum number assignments for the ordinary fermions. Using these conditions, we prove that the popular grand unified theories based on the gauge groups SO(10) and E6 can only accommodate trivial extensions of the standard model. As a consequence, if any of these grand unified models works at some energy scale, present low-energy neutral current phenomenology implies that the Z-boson must be produced with the expected mass and couplings to the ordinary fermions. Any additional neutral gauge boson (with the possible exception of very heavy ones) could only be produced in hadronic collisions and it would not decay in e + e - . (orig.)

  1. The Phobos low energy telescope charged particle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, R.G.; Henrion, J.P.G.; Wenzel, K.P. (European Space Agency, Noordwijk (Netherlands). Space Science Dept.); Afonin, V.V. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Balazs, A.; Erdoes, G.; Rusznyak, P.; Somogyi, A.; Szalai, S.; Varga, A.; Varhalmi, L. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics); Richter, A.K.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.))

    1990-05-01

    The Low Energy Telescope (LET) experiment on board the Phobos 1 and 2 spacecraft measures the flux, energy spectra and elemental composition of solar energetic particles and cosmic ray nuclei from hydrogen up to iron in the energy range {proportional to}1 to {proportional to}75 MeV/n. The LET sensor system comprises a double dE/dX vs E solid-state detector telescope surrounded by a cylindrical plastic scintillator anticoincidence shield, and the instrument is equipped with a comprehensive particle identifier and event priority system that enables rare nuclei to be analysed in preference to the more common species. Isotope separation for light nuclei such as He is also achieved. The sensor is mounted on a rotating platform to enable coarse anisotropy measurements of low energy protons to be made. (orig.).

  2. Luminescence model with quantum impact parameter for low energies

    International Nuclear Information System (INIS)

    Cruz G, H.S.; Michaelian, K.; Galindo U, S.; Martinez D, A.; Belmont M, E.

    2000-01-01

    The analytical model of induced light production in scintillator materials by energetic ions proposed by Michaelian and Menchaca (M-M) adjusts very well the luminescence substance data in a wide energy interval of the incident ions (10-100 MeV). However at low energies, that is, under to 10 MeV, the experimental deviations of the predictions of M-M model, show that the causes may be certain physical effects, all they important at low energies, which were not considered. We have modified lightly the M-M model using the basic fact that the Quantum mechanics gives to a different limit for the quantum impact parameter instead of the classic approximation. (Author)

  3. Negative ions as a source of low energy neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems.

  4. Low energy pion--nucleon and pion--deuteron interactions

    International Nuclear Information System (INIS)

    Burman, R.L.

    1975-01-01

    This survey concentrates upon current experiments in the fields of pion-nucleon and pion-deuteron interactions, for low-energy incident pions--below 300 MeV. The discussion is restricted to very recent work. The topics to be covered are: π +- p → π +- p, Elastic Scattering; π +- p → π +- pγ, Bremsstrahlung; π + d → pp, Absorption; π d → π + d, Elastic Scattering; and π + d → π + pn, Breakup. (14 figures) (U.S.)

  5. Low Energy Supersymmetry from the Heterotic String Landscape

    CERN Document Server

    Lebedev, O; Raby, S; Ramos-Sanchez, S; Ratz, M; Vaudrevange, P K S; Wingerter, A; Lebedev, Oleg; Nilles, Hans-Peter; Raby, Stuart; Ramos-Sanchez, Saul; Ratz, Michael; Vaudrevange, Patrick K. S.; Wingerter, Akin

    2007-01-01

    We study possible correlations between properties of the observable and hidden sectors in heterotic string theory. Specifically, we analyze the case of the Z6-II orbifold compactification which produces a significant number of models with the spectrum of the supersymmetric standard model. We find that requiring realistic features does affect the hidden sector such that hidden sector gauge group factors SU(4) and SO(8) are favoured. In the context of gaugino condensation, this implies low energy supersymmetry breaking.

  6. Low Energy Electron Gun on Board a Scientific Satellite GEOTAIL

    OpenAIRE

    TSUTSUI, Minoru; ONISHI, Yoshiaki; MATSUMOTO, Hiroshi; KIMURA, Iwane; 筒井, 稔; 大西, 嘉昭; 松本, 紘; 木村, 磐根

    1988-01-01

    A low energy electron gun to be used for beam-plasma interaction experiments by a scientific satellite GEOTAIL has been designed and manufactured. Electrodes of the gun have been modified from the Pierce type gun because of the use of a directly heated cathode. Spatial density distributions of beam electrons emitted from the new gun have been measured in a large vacuum chamber, and characteristic curves of emission currents for some beam energies and cathode powers have been checked repeatedl...

  7. Practical Use of Scanning Low Energy Electron Microscope (SLEEM)

    Czech Academy of Sciences Publication Activity Database

    Müllerová, Ilona; Mikmeková, Eliška; Mikmeková, Šárka; Konvalina, Ivo; Frank, Luděk

    2016-01-01

    Roč. 22, S3 (2016), s. 1650-1651 ISSN 1431-9276 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : scanning low energy * SLEEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

  8. The TRIUMF low energy pion spectrometer and channel

    International Nuclear Information System (INIS)

    Sobie, R.J.; Drake, T.E.; Barnett, B.M.; Erdman, K.L.; Gyles, W.; Johnson, R.R.; Roser, H.W.; Tacik, R.; Blackmore, E.W.; Gill, D.R.

    1983-08-01

    A low energy pion spectrometer has been developed for use with the TRIUMF M13 pion channel. The combined channel and spectrometer resolution is presently 1.1 MeV at T = 50 MeV. This is limited by the amount of gas and detector material in the spectrometer in addition to the inherent resolution of the channel. Improvements to both the spectrometer and channel are discussed

  9. Delayed hot spots in a low energy plasma focus

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1991-01-01

    In a low energy Mather-type plasma focus device, hot spots having temperature in the range of few keV have been observed even 1 μs after the pinch disintegration and in regions away from the pinch area. These hot spots are perhaps created by the thermal runaway due to temperature fluctuations in the background gas. (author). 12 refs., 6 figs

  10. Programs for low-energy nuclear physics data processing

    International Nuclear Information System (INIS)

    Antuf'ev, Yu.P.; Dejneko, A.S.; Ekhichev, O.I.; Kuz'menko, V.A.; Mashkarov, Yu.G.; Nemashkalo, B.A.; Skakun, E.A.; Storizhko, V.E.; Shlyakhov, N.A.

    1978-01-01

    Purpose of six computer programs developed in KhPTI of AN USSR for the processing of the experimental data on low energy nuclear physics ia friendly described. The programs are written in Algol-60 language. They are applied to some types of nuclear reactions and permit to process differential cross sections and γ spectra, to compute statistical tensors and excitation functions as well as to analyze some processes by means of theoretical models

  11. Radiation processing of natural polymers using low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2004-01-01

    Radiation processing is widely used in Japan and the economic scale of radiation application amounted to about 71 b$ (ratio relative to GDP: 1.7%) in total. It consisted of 60 b$ (85%) in industry, 10 b$ (14%) in medicine and 1 b$ (1%) in agriculture. Irradiation using gamma-ray from 60 Co and electron beam is commercially used for the sterilization and modification of materials. Utilization of natural polymers by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin were easily degraded by irradiation and induced various kinds of biological activities, i.e. anti-bacterial activity, elicitor activity, plant growth promotion, suppression of environmental stress on plants. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. Low energy electron beam (EB) irradiation has a variety of applications and good safety. A self-shielded low energy electron accelerator system needs an initial investment much lower than a 60 Co facility. It was demonstrated that the liquid sample irradiation system using low energy EB was effective not only for the preparation of degraded polysaccharides but also for radiation vulcanization of natural rubber latex (RVNRL). Some carbohydrate derivatives, carboxymethylcellulose (CMC), carboxymethyl-starch and carboxymethyl-chitin/chitosan, can be crosslinked under certain radiation condition and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  12. Method of making a low energy gamma ray collimator

    International Nuclear Information System (INIS)

    Muehllehner, Gerd.

    1975-01-01

    Described herein is a method for making a low energy gamma ray collimator which involves corrugating lead foil strips by passing them through pinion wire rollers and gluing corrugated strips between straight strips using an adhesive such as epoxy to build up a honeycomb-like structure. A thin aluminum sheet is glued to both edges of the strips to protect them and to provide a more rigid assembly which may be sawed to a desired shape. (Patent Office Record)

  13. Negative ions as a source of low energy neutral beams

    International Nuclear Information System (INIS)

    Fink, J.H.

    1980-01-01

    Little consideration has been given to the impact of recent developments in negative ion source technology on the design of low energy neutral beam injectors. However, negative ion sources of improved operating efficiency, higher gas efficiency, and smaller beam divergence will lead to neutral deuterium injectors, operating at less than 100 keV, with better operating efficiencies and more compact layouts than can be obtained from positive ion systems

  14. Sausage instability threshold in a low energy plasma focus

    International Nuclear Information System (INIS)

    Zakaullah, M.; Nasir, M.; Khattak, F.Y.; Murtaza, G.

    1993-01-01

    Development of sausage instability (m = 0 mode) is studied in a small low energy Mather-type plasma focus. A shadow graphic study of the current sheath has shown that the focused plasma necks off during the radial phase before the maximum compression. This may indicate the lowering of the instability threshold. Three hook-type structures are observed which may not be due to the multifoci formation. The bubble shape structure is observed to be developed in the expansion phase. (author)

  15. Low energy He+ irradiation effect on graphite surface

    International Nuclear Information System (INIS)

    Asari, E.; Nakamura, K.G.; Kitajima, M.; Kawabe, T.

    1992-01-01

    Study on the lattice disordering and the secondary electron emission under low energy (1-5keV) He + irradiation is reported. Real-time Raman measurements show that difference in the observed Raman spectra for different ion energies is due to the difference of the damage depth. The relation between the observed Raman spectrum and the depth profile of lattice damage is discussed. Energy dependence of the secondary electron emission coefficient are also described. (author)

  16. Low-energy phenomenology of a realistic composite model

    International Nuclear Information System (INIS)

    Korpa, C.; Ryzak, Z.

    1986-01-01

    The low-energy limit of the strongly coupled standard model (Abbott-Farhi composite model) is analyzed. The effects of the excited W isotriplet and isoscalar bosons are investigated and compared with experimental data. As a result, constraints on parameters (masses, coupling constants, etc.) of these vector bosons are obtained. They are not severe enough (certain cancellations are possible) to exclude the model on experimental basis

  17. Overview of Light Hydrogen-Based Low Energy Nuclear Reactions

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.

    This paper reviews light water and hydrogen-based low-energy nuclear reactions (LENRs) including the different methodologies used to study these reactions and the results obtained. Reports of excess heat production, transmutation reactions, and nuclear radiation emission are cited. An aim of this review is to present a summary of the present status of light water LENR research and provide some insight into where this research is heading.

  18. Elastic scattering of low energy electrons by hydrogen molecule

    International Nuclear Information System (INIS)

    Freitas, L.C.G.; Mu-Tao, L.; Botelho, L.F.

    1987-01-01

    The coherent version of the Renormalized Multiple-Centre Potential Model (RMPM) has been extended to treat the elastic scattering of low energy electrons by H2 molecule. The intramolecular Multiple Scattering (MS) effect has also been included. The comparison against the experimental data shows that the inclusion of the MS improves significantly with experiment. The extension of the present method to study electron-polyatomic molecule interaction is also discussed. (author) [pt

  19. Generation of low-energy muons with laser resonant ionization

    International Nuclear Information System (INIS)

    Matsuda, Y.; Bakule, P.; Iwasaki, M.; Matsuzaki, T.; Miyake, Y.; Ikedo, Y.; Strasser, P.; Shimomura, K.; Makimura, S.; Nagamine, K.

    2006-01-01

    We have constructed a low-energy muSR spectrometer at RIKEN-RAL muon facility in ISIS, the UK. With low-background of pulsed muon beam, and short pulse width from laser resonant ionization method, it is hoped this instrument will open new possibilities for studies of material sciences with muon beam. It is enphasized that this method is well suited to the facility where intense pulsed proton beam is available

  20. Low Energy Contrast of Metal Matrix Composite in SEM

    Czech Academy of Sciences Publication Activity Database

    Frank, Luděk; Matsuda, K.; Hrnčiřík, Petr; Müllerová, Ilona

    2003-01-01

    Roč. 9, Sup. 3 (2003), s. 328 - 329 ISSN 1431-9276. [MC 2003. Dresden, 07.09.2003-12.09.2003] R&D Projects: GA AV ČR IAA1065304 Institutional research plan: CEZ:AV0Z2065902 Keywords : low energy contrasts * scanning electron microscope * aluminium alloys Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.648, year: 2003

  1. Nuclear reactions video (knowledge base on low energy nuclear physics)

    International Nuclear Information System (INIS)

    Zagrebaev, V.; Kozhin, A.

    1999-01-01

    The NRV (nuclear reactions video) is an open and permanently extended global system of management and graphical representation of nuclear data and video-graphic computer simulation of low energy nuclear dynamics. It consists of a complete and renewed nuclear database and well known theoretical models of low energy nuclear reactions altogether forming the 'low energy nuclear knowledge base'. The NRV solves two main problems: 1) fast and visualized obtaining and processing experimental data on nuclear structure and nuclear reactions; 2) possibility for any inexperienced user to analyze experimental data within reliable commonly used models of nuclear dynamics. The system is based on the realization of the following principal things: the net and code compatibility with the main existing nuclear databases; maximal simplicity in handling: extended menu, friendly graphical interface, hypertext description of the models, and so on; maximal visualization of input data, dynamics of studied processes and final results by means of real three-dimensional images, plots, tables and formulas and a three-dimensional animation. All the codes are composed as the real Windows applications and work under Windows 95/NT

  2. Low Energy Electrons in the Mars Plasma Environment

    Science.gov (United States)

    Link, Richard

    2001-01-01

    The ionosphere of Mars is rather poorly understood. The only direct measurements were performed by the Viking 1 and 2 landers in 1976, both of which carried a Retarding Potential Analyzer. The RPA was designed to measure ion properties during the descent, although electron fluxes were estimated from changes in the ion currents. Using these derived low-energy electron fluxes, Mantas and Hanson studied the photoelectron and the solar wind electron interactions with the atmosphere and ionosphere of Mars. Unanswered questions remain regarding the origin of the low-energy electron fluxes in the vicinity of the Mars plasma boundary. Crider, in an analysis of Mars Global Surveyor Magnetometer/Electron Reflectometer measurements, has attributed the formation of the magnetic pile-up boundary to electron impact ionization of exospheric neutral species by solar wind electrons. However, the role of photoelectrons escaping from the lower ionosphere was not determined. In the proposed work, we will examine the role of solar wind and ionospheric photoelectrons in producing ionization in the upper ionosphere of Mars. Low-energy (internal (photoelectron) sources of ionization, and accounts for Auger electron production. The code will be used to analyze Mars Global Surveyor measurements of solar wind and photoelectrons down to altitudes below 200 km in the Mars ionosphere, in order to determine the relative roles of solar wind and escaping photoelectrons in maintaining plasma densities in the region of the Mars plasma boundary.

  3. Ultra-low energy storage ring at FLAIR

    International Nuclear Information System (INIS)

    Welsch, Carsten P.; Papash, A. I.; Gorda, O.; Harasimowicz, J.; Karamyshev, O.; Karamysheva, G.; Newton, D.; Panniello, M.; Putignano, M.; Siggel-King, M. R. F.; Smirnov, A.

    2012-01-01

    The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV and possibly less. The USR has been completely redesigned over the past three years. The ring structure is based on a “split achromat” lattice that allows in-ring experiments with internal gas jet target. Beam parameters might be adjusted in a wide range: from very short pulses in the nanosecond regime to a Coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Detailed investigations of the USR, including studies into the ring’s long term beam dynamics, life time, equilibrium momentum spread and equilibrium lateral spread during collisions with an internal target were carried out. New tools and beam handling techniques for diagnostics of ultra-low energy ions at beam intensities less than 10 6 were developed by the QUASAR Group. In this paper, progress on the USR project will be presented with an emphasis on the expected beam parameters available to the experiments at FLAIR.

  4. Energy sharing and sputtering in low-energy collision cascades

    International Nuclear Information System (INIS)

    Weller, R.A.; Weller, M.R.

    1982-01-01

    Using a non-linear transport equation to describe the energy-sharing process in an isotropic collision cascade, we have numerically calculated sputtered particle velocity spectra for several very low energy (=< 10 eV) primary recoil distributions. Our formulation of the sputtering process is essentially that used in the linear model and our equations yield the familiar linear model results in the appropriate limit. Discrepancies between our calculations and the linear model results in other cases may be understood by considering the effects of the linear model assumptions on the sputtering yield at very low energies. Our calculations are also compared with recent experimental results investigating ion-explosion sputtering. The results of this comparison support the conclusion that in insulators sputtering is initiated by very low energy recoil atoms when the energy of the incident beam is high enough that the stopping power is dominated by the electronic contribution. The calculations also suggest that energy spectra similar to those for evaporation may result from non-equilibrium processes but that the apparent temperatures of evaporation are not related in a simple way to any real temperature within the target. (author)

  5. Scanning ion microscopy with low energy lithium ions

    International Nuclear Information System (INIS)

    Twedt, Kevin A.; Chen, Lei; McClelland, Jabez J.

    2014-01-01

    Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500 eV to 5 keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process. - Highlights: • We use an ion source based on photoionization of laser-cooled lithium atoms. • The ion source makes possible a low energy (500 eV to 5 keV) scanning ion microscope. • Low energy is preferred for ion microscopy with backscattered ions. • We use the microscope to image a thin resist used in nano-imprint lithography

  6. Accuracy estimation for intermediate and low energy neutron transport calculation with Monte Carlo code MCNP

    International Nuclear Information System (INIS)

    Kotegawa, Hiroshi; Sasamoto, Nobuo; Tanaka, Shun-ichi

    1987-02-01

    Both ''measured radioactive inventory due to neutron activation in the shield concrete of JPDR'' and ''measured intermediate and low energy neutron spectra penetrating through a graphite sphere'' are analyzed using a continuous energy model Monte Carlo code MCNP so as to estimate calculational accuracy of the code for neutron transport in thermal and epithermal energy regions. Analyses reveal that MCNP calculates thermal neutron spectra fairly accurately, while it apparently over-estimates epithermal neutron spectra (of approximate 1/E distribution) as compared with the measurements. (author)

  7. Center for Coal-Derived Low Energy Materials for Sustainable Construction

    Energy Technology Data Exchange (ETDEWEB)

    Jewell, Robert; Robl, Tom; Rathbone, Robert

    2012-06-30

    The overarching goal of this project was to create a sustained center to support the continued development of new products and industries that manufacture construction materials from coal combustion by-products or CCB’s (e.g., cements, grouts, wallboard, masonry block, fillers, roofing materials, etc). Specific objectives includes the development of a research kiln and associated system and the formulation and production of high performance low-energy, low-CO2 emitting calcium sulfoaluminate (CAS) cement that utilize coal combustion byproducts as raw materials.

  8. Developing effective rockfall protection barriers for low energy impacts

    Science.gov (United States)

    Mentani, Alessio; Giacomini, Anna; Buzzi, Olivier; Govoni, Laura; Gottardi, Guido; Fityus, Stephen

    2016-04-01

    Recently, important progresses have been made towards the development of high capacity rockfall barriers (100 kJ - 8000 kJ). The interest of researchers and practitioners is now turning to the development of fences of minor capacity, whose use becomes essential in areas where rockfall events generally have low intensity and the use of high capacity barriers would be accompanied by excessive costs and high environmental impact. Low energy barriers can also provide a cost-effective solution even in areas where high energies events are expected. Results of full-scale tests are vital to any investigation on the behaviour of these structures. An experimental set-up has been developed at The University of Newcastle (AUS), to investigate the response of low energy rockfall barrier prototypes to low energy impacts. The Australian territory, and in particular New South Wales, is in fact characterised by rockfall events of low-to-medium intensity (50 kJ - 500 kJ) and the need of protection structures working within such energy range, is particularly felt [1]. The experiments involved the impact of a test block onto three spans, low energy barrier prototypes, made of steel structural posts, fully fixed at the base, side cables and a steel meshwork constituted by a double twist hexagonal wire net [2]. Test data enabled the development, calibration and assessment of FE models [3], on which non-linear and dynamic analyses have been performed addressing the effect of the block size. Results have shown that the response of the structure is strongly governed by the net. Data from tests conducted on the sole net and on the entire barrier showed in fact a similar trend, different to what typically observed for high capacity barriers, whose behaviour is also led by the presence of uphill cables and brakes. In particular, the numerical analyses have demonstrated a dependence of the net performance on the block size. In particular, a loss of capacity in the order of 50% occurred as the

  9. Low-energy electron microdosimetry of CS-137

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Wrenn, M.E.

    1980-09-01

    The mass of tissue irradiated by an internal emitter depends upon the distribution of the radionuclide within the organism and the type of radiation emitted. The range (95% absorption) of low-energy electron effectively defines the sensitive volume in which the energy of the emitted electron is deposited. Accordingly, in the case of Auger electron microdosimetry of internal emitters the correct definition of the sensitive volume is of paramount importance. The amount of energy delivered by the monoenergetic electrons emitted by the decay system 137 Cs → sup(137m)Ba to spherical volumes of water-like tissue media of radii equivalent to the estimated ranges of those electrons in water is calculated and discussed as far as the variations of the estimated ranges of electrons as a function of the initial energy of emission are concerned. Although there are still many uncertainties on the actual ranges of low-energy electrons, one can state confidently that the ranges of the Auger electrons of the decay system 137 Cs → 137 sup(m) Ba → 137 Ba can be considered to be in the same order of magnitude of the diameter of a cell. The energy deposition in spherical volumes of water-like tissue media, considered equivalent to the sensitive volumes for the Auger electrons of the decay system 137 Cs → 137 sub(m) Ba → 137 Ba, range for several orders of magnitude from 10 2 to about 10 10 times higher than the energy deposition in similar media by the internal conversion electrons of this decay system. If equivalent variations of energy deposition per unit mass occur when the masses considered are cellular, and subcellular structures, then the effects into the sensitive volume should be taken into biological consideration as far as the microdosimetry of low-energy electrons (approximately equal to 10 keV) is considered, whenever there is internal localization of Auger emitters. (Author) [pt

  10. Clinical application of low energy intracardiac cardioversion of atrial fibrillation

    International Nuclear Information System (INIS)

    Wu Liqun; Gu Gang; Su Kan; Su Renying; Shen Yongchu; Shen Weifeng

    2002-01-01

    Objective: To evaluate the efficacy and safety of low energy intracardiac cardioversion in persistent atria fibrillation. Methods: Low energy intracardiac cardioversion was performed by delivering R wave-synchronized biphasic shocks in 7 patients (4 men, 3 women) with persistent atrial fibrillation. Prior to the procedure, all patients underwent transesophageal echocardiographic examinations to rule out the presence of intracardiac thrombus and received subcutaneous injection of low molecular weight heparin for 3-5 days. Two custom-made 6 Fr catheters (Rhythm Technologies of Getz, USA) were used for de-fibrillation shock delivery. One catheter was positioned in the lower right atrium so that the majority of the catheter electrodes had firm contact with the right atrial free wall. The second catheter was placed randomly either in coronary sinus through right internal jugular vein or in the left pulmonary artery through femoral vein. In addition, a standard diagnostic 6-F quadrupolar catheter was placed at the right ventricular apex for ventricular synchronization and postshock ventricular pacing. Shocks were delivered by Implant Support Device (Model 4510, Teleceronics). After conversion, all patients were treated with intravenous amiodarone in the first 24 hours followed by oral administration. Results: In all 7 patients cardioversion of atrial fibrillation to sinus rhythm was successfully obtained. A mean of 2 ± 1 shocks per patient has been delivered with a total amount of 13 shocks. The average delivered energy was 7.8 ± 2.2 Joules. No complication occurred. At a mean follow-up of 18 ± 9 months, 4 of the 7 patients treated successfully showed sinus rhythm there after. Atrial fibrillation recurred in 3 patients at the second, fifth day and eighth month after cardioversion. Conclusions: Low energy intracardiac cardioversion is effective and safe, and can be easily performed in patients without general anesthesia. It offers a new option for restoring sinus

  11. Low energy electron beam processing of YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chromik, Š., E-mail: stefan.chromik@savba.sk [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Camerlingo, C. [CNR-SPIN, Istituto Superconduttori, Materiali Innovativi e Dispositivi, via Campi Flegrei 34, 80078 Pozzuoli (Italy); Sojková, M.; Štrbík, V.; Talacko, M. [Institute of Electrical Engineering, SAS, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Malka, I.; Bar, I.; Bareli, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Jung, G. [Department of Physics, Ben Gurion University of the Negev, P.O.B. 653, 84105 Beer Sheva (Israel); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland)

    2017-02-15

    Highlights: • Improvement of superconducting properties of irradiated bridges under certain conditions. • 30 keV irradiation influence CuO{sub 2} planes as well as oxygen chains. • Direct confirmation of changes in oxygen chains using micro-Raman spectroscopy. • Possibility of electron writing. - Abstract: Effects of low energy 30 keV electron irradiation of superconducting YBa{sub 2}Cu{sub 3}O{sub 7−δ} thin films have been investigated by means of transport and micro-Raman spectroscopy measurements. The critical temperature and the critical current of 200 nm thick films initially increase with increasing fluency of the electron irradiation, reach the maximum at fluency 3 − 4 × 10{sup 20} electrons/cm{sup 2}, and then decrease with further fluency increase. In much thinner films (75 nm), the critical temperature increases while the critical current decreases after low energy electron irradiation with fluencies below 10{sup 20} electrons/cm{sup 2}. The Raman investigations suggest that critical temperature increase in irradiated films is due to healing of broken Cu−O chains that results in increased carrier’s concentration in superconducting CuO{sub 2} planes. Changes in the critical current are controlled by changes in the density of oxygen vacancies acting as effective pinning centers for flux vortices. The effects of low energy electron irradiation of YBCO turned out to result from a subtle balance of many processes involving oxygen removal, both by thermal activation and kick-off processes, and ordering of chains environment by incident electrons.

  12. EPIDEMIOLOGICAL STUDY OF LOW ENERGY FRACTURES IN REPUBLIC OF ARMENIA

    Directory of Open Access Journals (Sweden)

    S. Saakyan

    2017-01-01

    Full Text Available Until present no data was available inArmeniain respect of incidence of low energy fractures that are typical of osteoporotic locations which consequently did not allow to evaluate the scope of this problem across the country.Purpose of the study – to identify the incidence of low energy fractures in proximal femur, in distal forearm, in proximal humerus and in distal tibia across population ofArmenia aged 50 years and older.Materials and methods. An observing population study was performed in two regions of Armenia during 2011-2013 where the frequency of selected locations in cases of moderate trauma was identified. During 2011-2012 the information was collected based on traumatology service records adding in 2013 other sources including primary level of healthcare due to observed infrequent applications for medical help in cases of trauma. Results. In 2013 the incidence of proximal femur fractures in men was reported as 136 cases per 100 000 of population aged 50 years and older, in women – 201 cases per 100 000. At the same time only 57.7% of patients with proximal femur fractures were admitted to hospital. Distal forearm fractures incidence in men and women was observed correspondingly 56/100 000 and 176/100 000 cases, proximal humerus fractures – 39/100 000 and 86/100 000 cases and distal tibia fractures – 39/100 000 and 86/100 000 cases. The predicted annual number of proximal femur fracture in Armenia amounts to 2067 cases, distal forearm fractures – 1205, proximal humerus fractures – 640.Conclusion. Epidemiological data that was collected for the first time on low energy fractures incidence confirmed the acute osteoporosis issue inArmenia and revealed the problems in organization of medical care for the group of senior patients with injuries.

  13. Collisions between low-energy antihydrogen and atoms

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Chamberlain, C.W.; Liu, Y.; Martin, G.D.R.

    2004-01-01

    Antihydrogen is currently the subject of great interest as cold H-bar has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH-bar scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H-bar system and give a progress report on the calculation that we are currently carrying out for this system

  14. Use of a streamer chamber for low energy nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Van Bibber, K.; Pang, W.; Avery, M.; Bloemhof, E.

    1979-10-01

    A small streamer chamber has been implemented for low energy heavy ion reaction studies at the LBL 88-inch cyclotron. The response of the chamber to light and heavy ions below 35 MeV/nucleon has been examined. The limited sensitivity of light output as a function of ionization works to advantage in recording a wide variety of tracks in the same photograph whose energy loss may vary considerably. Furthermore, as gas targets are attractive for several reasons, we have investigated the suitability of Ar and Xe for use in streamer chambers.

  15. Use of a streamer chamber for low energy nuclear physics

    International Nuclear Information System (INIS)

    Van Bibber, K.; Pang, W.; Avery, M.; Bloemhof, E.

    1979-10-01

    A small streamer chamber has been implemented for low energy heavy ion reaction studies at the LBL 88-inch cyclotron. The response of the chamber to light and heavy ions below 35 MeV/nucleon has been examined. The limited sensitivity of light output as a function of ionization works to advantage in recording a wide variety of tracks in the same photograph whose energy loss may vary considerably. Furthermore, as gas targets are attractive for several reasons, we have investigated the suitability of Ar and Xe for use in streamer chambers

  16. MITP Workshop on Low-Energy Precision Physics

    CERN Document Server

    2013-01-01

    The scientific program will be focussed on the theory of low-energy precision physics relevant to the MESA and TRIGA initiatives. Topics include searches for TeV-scale physics beyond the Standard Model via ultra-precise measurements of parity-violating electron scattering asymmetries, determinations of neutron decay parameters via precision measurements of its lifetime and decay asymmetries, and searches for EDMs of nucleons, nuclei and atoms. The necessary high-precision theoretical tools to analyse these experiments, which include advanced calculations of radiative corrections, will be explored and developed.

  17. Energy loss and thermalization of low-energy electrons

    International Nuclear Information System (INIS)

    LaVerne, J.A.; Mozumder, A.; Notre Dame Univ., IN

    1984-01-01

    Various processes involved in the moderation of low-energy electrons (< 10 keV in energy) have been delineated in gaseous and liquid media. The discussion proceeds in two stages. The first stage ends and the second stage begins when the electron energy equals the first excitation potential of the medium. The second stage ends with thermalization. Cross sections for electronic excitation and for the excitation (and de-excitation) of sub-electronic processes have been evaluated and incorporated in suitable stopping power and transport theories. Comparison between experiment and theory and intercomparisons between theories and experiments have been provided where possible. (author)

  18. Shock waves in water at low energy pulsed electric discharges

    International Nuclear Information System (INIS)

    Pinchuk, M E; Kolikov, V A; Rutberg, Ph G; Leks, A G; Dolinovskaya, R V; Snetov, V N; Stogov, A Yu

    2012-01-01

    Experimental results of shock wave formation and propagation in water at low energy pulsed electric discharges are presented. To study the hydrodynamic structure of the shock waves, the direct shadow optical diagnostic device with time resolution of 5 ns and spatial resolution of 0.1 mm was designed and developed. Synchronization of the diagnostic and electrodischarge units by the fast optocouplers was carried out. The dependences of shock wave velocities after breakdown of interelectrode gap for various energy inputs (at range of ≤1 J) into discharge were obtained. Based on the experimental results the recommendations for the adjustment parameters of the power supply and load were suggested.

  19. Interpretation of diffuse low-energy electron diffraction intensities

    International Nuclear Information System (INIS)

    Saldin, D.K.; Pendry, J.B.; Van Hove, M.A.; Somorjai, G.A.

    1985-01-01

    It is shown that the diffuse low-energy electron diffraction (LEED) that occurs between sharp LEED beams can be used to determine the local bonding configuration near disordered surface atoms. Two approaches to the calculation of diffuse LEED intensities are presented for the case of lattice-gas disorder of an adsorbate on a crystalline substrate. The capabilities of this technique are most similar to those of near-edge extended x-ray absorption fine structure, but avoid the restrictions due to the use of photons

  20. Low-energy house in Sisimiut - Data overview

    Energy Technology Data Exchange (ETDEWEB)

    Hvidthoeft Delff Andersen, P.; Rode, C.; Madsen, Henrik

    2013-08-15

    Experiments with persistently exciting heat inputs are a fundamental tool in identification of heat dynamics in buildings. The Low-energy house in Sisimiut, Greenland, provides an advanced experimental setup with frequent measurements of temperatures, heat inputs, and much more. This paper presents an overview of data collected since the installation of the new measurement and control system. Focus is on heat dynamics so only data related to that will be shown. 5 experiments have been conducted. They are described, and resulting data is shown. (Author)

  1. Degradation of vitamin C by low-energy electrons

    Science.gov (United States)

    Abdoul-Carime, Hassan; Illenberger, Eugen

    2004-06-01

    We report on the degradation of gas phase vitamin C (ascorbic acid, AA) induced by low-energy electrons. In the energy range of (0-12) eV, different negatively charged fragments, attributed to the dehydro-ascorbic acid anion ((AA-H) -), OH -, O - and H -, are observed. The yield functions indicate that these ions are formed via dissociative electron attachment, DEA. While the formation of (AA-H) - is exclusively observed at sub-excitation energies (<1.5 eV), the other fragments arise from resonance features at higher energies. Possible implications of these observations for radiation damage and food treatment by high energy radiation are considered.

  2. Low energy, low cost, efficient CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Michael C. Trachtenberg; Lihong Bao; David A. Smith; Remy Dumortier [Carbozyme, Inc., Monmouth Junction, NJ (United States)

    2006-07-01

    This paper discusses the development and some characteristics of a new, enzyme-based, contained liquid membrane contactor to capture CO{sub 2}. The enzyme carbonic anhydrase catalyzes the removal of CO{sub 2} while the membrane contactor increases the surface area to allow the reduction of the size of the system. The modular system design is easily scaled to any required size reducing the investment costs. The system captures CO{sub 2} at a low energy and low cost promising to be a cost effective technology for CO{sub 2} capture. 5 refs., 7 figs.

  3. Collisions between low-energy antihydrogen and atoms

    Energy Technology Data Exchange (ETDEWEB)

    Armour, E.A.G. E-mail: edward.armour@nottingham.ac.uk; Chamberlain, C.W.; Liu, Y.; Martin, G.D.R

    2004-07-01

    Antihydrogen is currently the subject of great interest as cold H-bar has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH-bar scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H-bar system and give a progress report on the calculation that we are currently carrying out for this system.

  4. Measurements of low energy neutral hydrogen efflux during ICRF heating

    International Nuclear Information System (INIS)

    Cohen, S.A.; Ruzic, D.; Voss, D.E.

    1984-09-01

    Using the Low Energy Neutral Atom Spectrometer, measurements were made of the H 0 and D 0 efflux from PLT during ion cyclotron heating experiments. The application of rf power at frequencies appropriate to fundamental and 2nd-harmonic heating results in a rapid, toroidally uniform rise in the charge-exchange efflux at a rate of about 10 15 cm -2 s -1 MW -1 . This flux increase is larger at lower plasma currents. The cause of this flux and its impact on plasma behavior are discussed

  5. Radiation degradation of marine polysaccharides by low energy electron beam

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Nagasawa, Naotsugu; Kume, Tamikazu

    2003-01-01

    The radiation degradations of marine polysaccharides by both gamma Co-60 and electron beam irradiations are investigated. Polysaccharides and oligosaccharides can be produced by degradation of corresponding polysaccharides including marine polysaccharides such as alginates, chitin chitosan and carrageenan. The viscosity of alginate, chitosan and carrageenan solution decreases markedly with increase of the low energy electron beam irradiation time and the beam current. Furthermore, the viscosity is reduced sharply in short time for polysaccharide solution with low concentration, for instance carrageenan solution of 1%. (author)

  6. Treatment of surfaces with low-energy electrons

    Czech Academy of Sciences Publication Activity Database

    Frank, Luděk; Mikmeková, Eliška; Lejeune, M.

    2017-01-01

    Roč. 407, JUN 15 (2017), s. 105-108 ISSN 0169-4332 R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Low- energy electrons * Electron beam induced release * Graphene * Ultimate cleaning of surfaces Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Nano-processes (applications on nano-scale) Impact factor: 3.387, year: 2016

  7. The Low Energy Level Structure of {sup 191}lr

    Energy Technology Data Exchange (ETDEWEB)

    Malmskog, S G; Berg, V [AB Atomenergi, Nykoeping (Sweden); [Inst. of Physics, U niv. of Stockholm (Sweden); Baecklin, A; Hedin, G [Inst. of Physics, Univ. of Upp sala (Sweden)

    1970-02-15

    The decay of {sup 191}Pt to {sup 191}Ir has been investigated using Ge(Li)-detectors and a double focusing beta spectrometer. 35 transitions were observed and most of them were placed in a level scheme. Special attention was given to the low energy level band structure. Several multipolarity mixing ratios were determined from L-subshell ratio measurements. Using the delayed coincidence technique the half-life of the 179.05 keV level was measured to 40 {+-} 12 psec. The low level decay properties are discussed in terms of the Nilsson model with the inclusion of Coriolis coupling.

  8. GEANT4 simulations for low energy proton computerized tomography

    International Nuclear Information System (INIS)

    Milhoretto, Edney; Schelin, Hugo R.; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A.; Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O.; Lopes, Ricardo T.; Vinagre Filho, Ubirajara M.

    2010-01-01

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  9. GEANT4 simulations for low energy proton computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Milhoretto, Edney [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O. [Polytechnic Institute/UERJ, Rua Alberto Rangel s/n, N. Friburgo, RJ, Brazil 28630-050 (Brazil); Lopes, Ricardo T. [Nuclear Instr. Lab./COPPE/UFRJ, Av. Horacio Macedo 2030, Rio de Janeiro-RJ (Brazil); Vinagre Filho, Ubirajara M. [Institute of Nuclear Engineering-IEN/CNEN, Rua Helio de Almeida 75, Rio de Janeiro-RJ (Brazil)

    2010-04-15

    This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

  10. A simple model for low energy ion-solid interactions

    International Nuclear Information System (INIS)

    Mohajerzadeh, S.; Selvakumar, C.R.

    1997-01-01

    A simple analytical model for ion-solid interactions, suitable for low energy beam depositions, is reported. An approximation for the nuclear stopping power is used to obtain the analytic solution for the deposited energy in the solid. The ratio of the deposited energy in the bulk to the energy deposited in the surface yields a ceiling for the beam energy above which more defects are generated in the bulk resulting in defective films. The numerical evaluations agree with the existing results in the literature. copyright 1997 American Institute of Physics

  11. Low-energy CZT detector array for the ASIM mission

    DEFF Research Database (Denmark)

    Cenkeramaddi, Linga Reddy; Genov, Georgi; Kohfeldt, Anja

    2012-01-01

    In this article we introduce the low-energy CZT (CdZnTe) 16 384-pixel detector array on-board the Atmosphere Space Interaction Monitor (ASIM), funded by the European Space Agency. This detector is a part of the larger Modular X-and Gamma-ray sensor (MXGS). The CZT detector array is sensitive...... to photons with energies between 15 keV and 400 keV. The principal objective of the MXGS instrument is to detect Terrestrial Gamma ray Flashes (TGFs), which are related to thunderstorm activity. The concept of the detector array is presented, together with brief descriptions of its mechanical structure...

  12. The low energy tagger for the KLOE-2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Babusci, D. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Bini, C. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Ciambrone, P.; Corradi, G. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); De Santis, A.; De Zorzi, G.; Di Domenico, A. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Fiore, S., E-mail: salvatore.fiore@roma1.infn.i [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Gauzzi, P. [Dipartimento di Fisica dell' universita Sapienza di Roma, p.le Aldo Moro 2, 00185 Roma (Italy); INFN sezione di Roma, Roma (Italy); Iannarelli, M.; Miscetti, S.; Paglia, C.; Tagnani, D.; Turri, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy)

    2010-05-21

    The KLOE experiment at the upgraded DAFNE e{sup +}e{sup -} collider in Frascati (KLOE-2) is going to start a new data taking at the beginning of 2010 with its detector upgraded with a tagging system for the identification of gamma-gamma interactions. The tagging stations for low-energy e{sup +}e{sup -} will consist in two calorimeters placed between the beam-pipe outer support structure and the inner wall of the KLOE drift chamber. This calorimeter will be made of LYSO crystals readout by Silicon Photomultipliers, to achieve an energy resolution better than 8% at 200 MeV.

  13. The interaction of low-energy electrons with fructose molecules

    Science.gov (United States)

    Chernyshova, I. V.; Kontrosh, E. E.; Markush, P. P.; Shpenik, O. B.

    2017-11-01

    Using a hypocycloidal electronic spectrometer, the interactions of low energy electrons (0-8.50 eV) with fructose molecules, namely, electron scattering and dissociative attachment, are studied. The results of these studies showed that the fragmentation of fructose molecules occurs effectively even at an electron energy close to zero. In the total electron-scattering cross section by molecules, resonance features (at energies 3.10 and 5.00 eV) were first observed near the formation thresholds of light ion fragments OH- and H-. The correlation of the features observed in the cross sections of electron scattering and dissociative attachment is analyzed.

  14. Selected challenges in low-energy QCD and hadron physics

    Energy Technology Data Exchange (ETDEWEB)

    Weise, Wolfram [Physik-Department, Technische Universitaet Muenchen, D-85747 Garching (Germany)

    2009-11-15

    This presentation briefly addresses three basic issues of low-energy QCD: first, whether the Nambu-Goldstone scenario of spontaneous chiral symmetry breaking is well established; secondly, whether there is a dynamical entanglement of the chiral and deconfinement crossover transitions in QCD; and thirdly, what is the status of knowledge about the phase diagram of QCD at low temperature and non-zero baryon density. These three topics were injected as key words into a panel discussion at the Schladming school on Challenges in QCD. The following exposition reflects the style and character of the discussions, with no claim of completeness.

  15. Qt based control system software for Low Energy Accelerator Facility

    International Nuclear Information System (INIS)

    Basu, A.; Singh, S.; Nagraju, S.B.V.; Gupta, S.; Singh, P.

    2012-01-01

    Qt based control system software for Low Energy Accelerating Facility (LEAF) is operational at Bhabha Atomic Research Centre (BARC), Trombay, Mumbai. LEAF is a 50 keV negative ion electrostatic accelerator based on SNICS ion source. Control system uses Nokia Trolltech's QT 4.x API for control system software. Ni 6008 USB based multifunction cards has been used for control and read back field equipments such as power supplies, pumps, valves etc. Control system architecture is designed to be client server. Qt is chosen for its excellent GUI capability and platform independent nature. Control system follows client server architecture. The paper will describe the control system. (author)

  16. Early forest fire detection using low-energy hydrogen sensors

    Directory of Open Access Journals (Sweden)

    K. Nörthemann

    2013-11-01

    Full Text Available Most huge forest fires start in partial combustion. In the beginning of a smouldering fire, emission of hydrogen in low concentration occurs. Therefore, hydrogen can be used to detect forest fires before open flames are visible and high temperatures are generated. We have developed a hydrogen sensor comprising of a metal/solid electrolyte/insulator/semiconductor (MEIS structure which allows an economical production. Due to the low energy consumption, an autarkic working unit in the forest was established. In this contribution, first experiments are shown demonstrating the possibility to detect forest fires at a very early stage using the hydrogen sensor.

  17. Electronuclear amplifiers with low-energy proton beams

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Shelaev, I.A.

    1998-01-01

    The use of proton accelerators with energy 200-300 MeV in subcritical electronuclear systems seems more preferable in comparison with more complicated and expensive machines with energy about 1 GeV, which are considered as favourite now. Such an approach allows one to build comparatively simple electronuclear plants in particular, for a safety and profitable incineration of plutonium from power plants and spells, in fact, a new strategy of electronuclear technology. Potentialities of the use of low-energy accelerators are illustrated by an electronuclear arrangements designed now in Dubna

  18. Some advances in medical applications of low energy accelerators

    Science.gov (United States)

    Valković, V.; Moschini, G.

    1991-05-01

    Medical applications of low energy accelerators include: the use of nuclear analytical methods and procedures for laboratory studies and routine measurements; material productions and modifications to meet special requirements; radioisotope productions and their applications in radiopharmaceuticals as well as in positron emission tomography; and radiotherapy with ions, based on improved understanding of the interaction of charged particles with living tissue. Some of the recent advances in these fields are critically summarized. The plan for an improved charged particle facility in a hospital environment dedicated to applications in biology and medicine is presented.

  19. Combining high-scale inflation with low-energy SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan [Basel Univ. (Switzerland). Dept. of Physics; Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut; Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Halter, Sebastian [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut

    2011-12-15

    We propose a general scenario for moduli stabilization where low-energy supersymmetry can be accommodated with a high scale of inflation. The key ingredient is that the stabilization of the modulus field during and after inflation is not associated with a single, common scale, but relies on two different mechanisms. We illustrate this general scenario in a simple example, where during inflation the modulus is stabilized with a large mass by a Kaehler potential coupling to the field which provides the inflationary vacuum energy via its F-term. After inflation, the modulus is stabilized, for instance, by a KKLT superpotential. (orig.)

  20. Status of the low energy neutron source at Indiana University

    International Nuclear Information System (INIS)

    Baxter, D.V.; Cameron, J.M.; Derenchuk, V.P.; Lavelle, C.M.; Leuschner, M.B.; Lone, M.A.; Meyer, H.O.; Rinckel, T.; Snow, W.M.

    2005-01-01

    The National Science Foundation has recently approved funding for LENS (the low energy neutron source) at Indiana University and construction of this facility has begun. LENS represents a new paradigm for economically introducing neutron scattering into a university or industrial setting. In this design, neutrons are produced in a long-pulse (1 ms) mode through (p,n) reactions on a water-cooled Be target and the target is tightly coupled to a cryogenic moderator with a water reflector. This design gives a facility suitable for materials research, the development of new neutron instrumentation, and the education of new neutron scientists

  1. Determination of the low energy spectra in the superstring theory

    International Nuclear Information System (INIS)

    Rausch de Traubenberg, M.

    1990-01-01

    There is one solution to the superstring theory in 10 dimensions (SO(32) ou E8xE8) but in a 4-dimensions space, there are plenty of solutions, so a classification is necessary. The author has used a formulation named fermionic, where the solution is easy to build and he has developed a program in terms of formal calculation (REDUCE). In a first time, this program verifies the constraints induced by the modular invariance and then reproduces the low energy spectra

  2. Introduction to the theory of low-energy electron diffraction

    International Nuclear Information System (INIS)

    Fingerland, A.; Tomasek, M.

    1975-01-01

    An elementary introduction to the basic principles of the theory of low-energy electron diffraction is presented. General scattering theory is used to classify the hitherto known approaches to the problem (optical potential and one-electron approximation; formal scattering theory: Born expansion and multiple scattering; translational symmetry: Ewald construction; classification of LEED theories by means of the T matrix; pseudokinematical theory for crystal with clean surface and with an adsorbed monomolecular layer; dynamical theory; inclusion of inelastic collisions; discussion of a simple example by means of the band-structure approach)

  3. Low-energy electron scattering from molecules, biomolecules and surfaces

    CERN Document Server

    Carsky, Petr

    2011-01-01

    Since the turn of the 21st century, the field of electron molecule collisions has undergone a renaissance. The importance of such collisions in applications from radiation chemistry to astrochemistry has flowered, and their role in industrial processes such as plasma technology and lighting are vital to the advancement of next generation devices. Furthermore, the development of the scanning tunneling microscope highlights the role of such collisions in the condensed phase, in surface processing, and in the development of nanotechnology.Low-Energy Electron Scattering from Molecules, Biomolecule

  4. Collisions between low-energy antihydrogen and atoms

    CERN Document Server

    Armour, E A G; Liu, Y; Martin, G D R

    2004-01-01

    Antihydrogen is currently the subject of great interest as cold H has recently been prepared at CERN by the ATHENA and ATRAP projects. This work is described elsewhere in this volume. In this paper, we describe a calculation that we have carried out recently for very low-energy HH scattering using the Kohn variational method and including three rearrangement channels in addition to the elastic channel. We also consider the He-H system and give a progress report on the calculation that we are currently carrying out for this system.

  5. The low energy tagger for the KLOE-2 experiment

    International Nuclear Information System (INIS)

    Babusci, D.; Bini, C.; Ciambrone, P.; Corradi, G.; De Santis, A.; De Zorzi, G.; Di Domenico, A.; Fiore, S.; Gauzzi, P.; Iannarelli, M.; Miscetti, S.; Paglia, C.; Tagnani, D.; Turri, E.

    2010-01-01

    The KLOE experiment at the upgraded DAFNE e + e - collider in Frascati (KLOE-2) is going to start a new data taking at the beginning of 2010 with its detector upgraded with a tagging system for the identification of gamma-gamma interactions. The tagging stations for low-energy e + e - will consist in two calorimeters placed between the beam-pipe outer support structure and the inner wall of the KLOE drift chamber. This calorimeter will be made of LYSO crystals readout by Silicon Photomultipliers, to achieve an energy resolution better than 8% at 200 MeV.

  6. Low-energy gamma rays from Cygnus X-1

    International Nuclear Information System (INIS)

    Roques, J.P.; Mandrou, P.; Lebrun, F.; Paul, J.

    1985-08-01

    Cyg X-1 was observed by the CESR balloon borne telescope OPALE, in June 1976. The high-energy spectrum of the source, which was in its ''superlow state'', was seen to extend well beyond 1 MeV. In this paper, the observed low-energy γ-ray component of Cyg X-1 is compared with the predictions of recent models involving accretion onto a stellar black hole, and including a possible contribution from the pair-annihilation 511 keV γ-ray line

  7. Implantation profile of low-energy positrons in solids

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Lynn, K.G.

    1990-01-01

    A simple form for an implantation profile of monoenergetic, low-energy (1--10 keV) positrons in solids is presented. Materials studied include aluminum, copper, molybdenum, palladium, and gold with atomic number ranging from 13 to 79. A simple set of parameters can describe the currently used Makhov profile in slow positron studies of solids. We provide curves and tables for the parameters that can be used to describe the implantation profiles of positrons in any material with atomic number in between 13 and 79

  8. Mott transition: Low-energy excitations and superconductivity

    International Nuclear Information System (INIS)

    Ioffe, L.B.; Larkin, A.I.

    1988-09-01

    It is possible that metal-dielectric transition does not result in changes of magnetic or crystallographic symmetry. In this case a fermionic spectrum is not changed at the transition, but additional low-energy excitations appear which can be described as a gauge field that has the same symmetry as an electromagnetic one. In the case of a non half-filled band gapless scalar Bose excitations also appear. Due to the presence of additional gauge field the physical conductivity is determined by the lowest conductivity of the Fermi or Bose subsystems. (author). 11 refs

  9. Low energy electron beams for industrial and environmental applications

    CERN Document Server

    Skarda, Vlad

    2017-01-01

    EuCARD-2 Workshop, 8-9 December 2016, Warsaw, Poland. Organizers: Science and Technology Facilities Council, UK CERN - The European Organization for Nuclear Research, Switzerland, Institute of Nuclear Chemistry and Technology, Poland, Fraunhofer Institute for Electron Beam and Plasma Technology, Germany, Warsaw University of Technology, Poland. An article presents short information about EuCARD-2 Workshop “Low energy electron beams for industrial and environmental applications”, which was held in December 2016 in Warsaw. Objectives, main topics and expected output of meeting are described. List of organizers is included.

  10. Proceedings of RIKEN BNL Resarch Center Workshop: Fluctuations, Correlations and RHIC Low Energy Runs

    Energy Technology Data Exchange (ETDEWEB)

    Karsch, F.; Kojo, T.; Mukherjee, S.; Stephanov, M.; Xu, N.

    2011-10-27

    background for the search of the CEP using observables related to fluctuations and correlations. While new data are pouring in from the RHIC low energy scan program, many recent advances have also been made in the phenomenological and lattice gauge theory sides in order to have a better theoretical understanding of the wealth of new data. This workshop tried to create a synergy between the experimental, phenomenological and lattice QCD aspects of the fluctuation and correlation related studies of the RHIC low energy scan program. The workshop brought together all the leading experts from related fields under the same forum to share new ideas among themselves in order to streamline the continuing search of CEP in the RHIC low energy scan program.

  11. Development of a low energy micro sheet forming machine

    Science.gov (United States)

    Razali, A. R.; Ann, C. T.; Shariff, H. M.; Kasim, N. I.; Musa, M. A.; Ahmad, A. F.

    2017-10-01

    It is expected that with the miniaturization of materials being processed, energy consumption is also being `miniaturized' proportionally. The focus of this study was to design a low energy micro-sheet-forming machine for thin sheet metal application and fabricate a low direct current powered micro-sheet-forming machine. A prototype of low energy system for a micro-sheet-forming machine which includes mechanical and electronic elements was developed. The machine was tested for its performance in terms of natural frequency, punching forces, punching speed and capability, energy consumption (single punch and frequency-time based). Based on the experiments, the machine can do 600 stroke per minute and the process is unaffected by the machine's natural frequency. It was also found that sub-Joule of power was required for a single stroke of punching/blanking process. Up to 100micron thick carbon steel shim was successfully tested and punched. It concludes that low power forming machine is feasible to be developed and be used to replace high powered machineries to form micro-products/parts.

  12. Low energy recoil detection with a spherical proportional counter

    Science.gov (United States)

    Savvidis, I.; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2018-01-01

    We present results for the detection of low energy nuclear recoils in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An 241Am-9Be fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the keV energy region was measured by observing the 5.9 keV line of a 55Fe X-ray source, with energy resolution of 10% (σ). The toolkit GEANT4 was used to simulate the irradiation of the detector by an 241Am-9Be source, while SRIM was used to calculate the Ionization Quenching Factor (IQF), the simulation results are compared with the measurements. The potential of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searches (via coherent elastic scattering).

  13. Development of Low Energy Gap and Fully Regioregular Polythienylenevinylene Derivative

    Directory of Open Access Journals (Sweden)

    Tanya M. S. David

    2014-01-01

    Full Text Available Low energy gap and fully regioregular conjugated polymers find its wide use in solar energy conversion applications. This paper will first briefly review this type of polymers and also report synthesis and characterization of a specific example new polymer, a low energy gap, fully regioregular, terminal functionalized, and processable conjugated polymer poly-(3-dodecyloxy-2,5-thienylene vinylene or PDDTV. The polymer exhibited an optical energy gap of 1.46 eV based on the UV-vis-NIR absorption spectrum. The electrochemically measured highest occupied molecular orbital (HOMO level is −4.79 eV, resulting in the lowest unoccupied molecular orbital (LUMO level of −3.33 eV based on optical energy gap. The polymer was synthesized via Horner-Emmons condensation and is fairly soluble in common organic solvents such as tetrahydrofuran and chloroform with gentle heating. DSC showed two endothermic peaks at 67°C and 227°C that can be attributed to transitions between crystalline and liquid states. The polymer is thermally stable up to about 300°C. This polymer appears very promising for cost-effective solar cell applications.

  14. rf quadrupole linac: a new low-energy accelerator

    International Nuclear Information System (INIS)

    Hamm, R.W.; Crandall, K.R.; Fuller, C.W.

    1980-01-01

    A new concept in low-energy particle accelerators, the radio-frequency quadrupole (RFQ) linac, is currently being developed at the Los Alamos National Scientific Laboratory. In this new linear accelerating structure both the focusing and accelerating forces are produced by the rf fields. It can accept a high-current, low-velocity dc ion beam and bunch it with a high capture efficiency. The performance of this structure as a low-energy linear accelerator has been verified with the successful construction of a proton RFQ linac. This test structure has accelerated 38 mA of protons from 100 keV to 640 keV in 1.1 meters with a capture efficiency greater than 80%. In this paper a general description of the RFQ linac and an outline of the basic RFQ linac design procedure are presented in addition to the experimental results from the test accelerator. Finally, several applications of this new accelerator are discussed

  15. Formation of a high intensity low energy positron string

    Science.gov (United States)

    Donets, E. D.; Donets, E. E.; Syresin, E. M.; Itahashi, T.; Dubinov, A. E.

    2004-05-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5×109 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production.

  16. Formation of a high intensity low energy positron string

    International Nuclear Information System (INIS)

    Donets, E.D.; Donets, E.E.; Syresin, E.M.; Itahashi, T.; Dubinov, A.E.

    2004-01-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5x10 9 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production

  17. Low-energy control of electrical turbulence in the heart

    Science.gov (United States)

    Luther, Stefan; Fenton, Flavio H.; Kornreich, Bruce G.; Squires, Amgad; Bittihn, Philip; Hornung, Daniel; Zabel, Markus; Flanders, James; Gladuli, Andrea; Campoy, Luis; Cherry, Elizabeth M.; Luther, Gisa; Hasenfuss, Gerd; Krinsky, Valentin I.; Pumir, Alain; Gilmour, Robert F.; Bodenschatz, Eberhard

    2011-07-01

    Controlling the complex spatio-temporal dynamics underlying life-threatening cardiac arrhythmias such as fibrillation is extremely difficult, because of the nonlinear interaction of excitation waves in a heterogeneous anatomical substrate. In the absence of a better strategy, strong, globally resetting electrical shocks remain the only reliable treatment for cardiac fibrillation. Here we establish the relationship between the response of the tissue to an electric field and the spatial distribution of heterogeneities in the scale-free coronary vascular structure. We show that in response to a pulsed electric field, E, these heterogeneities serve as nucleation sites for the generation of intramural electrical waves with a source density ρ(E) and a characteristic time, τ, for tissue depolarization that obeys the power law τ~Eα. These intramural wave sources permit targeting of electrical turbulence near the cores of the vortices of electrical activity that drive complex fibrillatory dynamics. We show in vitro that simultaneous and direct access to multiple vortex cores results in rapid synchronization of cardiac tissue and therefore, efficient termination of fibrillation. Using this control strategy, we demonstrate low-energy termination of fibrillation in vivo. Our results give new insights into the mechanisms and dynamics underlying the control of spatio-temporal chaos in heterogeneous excitable media and provide new research perspectives towards alternative, life-saving low-energy defibrillation techniques.

  18. Do paralympic track and field athletes have low energy availability?

    Directory of Open Access Journals (Sweden)

    Daniel Paduan Joaquim

    2018-03-01

    Full Text Available One of the greatest challenges when working with athletes is to achieve the energy demands for physiological processes and exercise expenditure. The aim of this study was to assess the energy availability (EA of Paralympic track and field athletes (sprinters. Seventeen athletes (9 male and 8 female with visual impairment (VI, n=10, cerebral palsy (CP, n=4 and limb deficiency (LD, n=3 were assessed for energy intake (EI (4-day food photographic record, energy expenditure with exercise (EEex (motion sensor, and body composition (skinfolds method. Energy availability was estimated using the equation: EA = (EIkcal - EEexkcal / fat-free mass (FFM / day, and values ≤ 30kcal/kgFFM/day were considered as low energy availability (LEA. EEex varied from 130 to 477kcal/h and athletes trained in average for 3.2 hours per day. Mean EA for VI, LD and CP were 36 (2.19, 37 (1.90 and 38 (3.38 kcal/kgFFM/day, respectively. Most (82.3% participants presented EA below ≥ 45kcal/kgFFM/day, throughout the days, which are the recommended values for athletes without disability. Athletes should be encouraged to consume adequate EA to avoid consequences related to low energy availability. There is need of further research to identify cut-off values adequate for this population.

  19. Low-energy-state dynamics of entanglement for spin systems

    International Nuclear Information System (INIS)

    Jafari, R.

    2010-01-01

    We develop the ideas of the quantum renormalization group and quantum information by exploring the low-energy-state dynamics of entanglement resources of a system close to its quantum critical point. We demonstrate that low-energy-state dynamical quantities of one-dimensional magnetic systems can show a quantum phase transition point and show scaling behavior in the vicinity of the transition point. To present our idea, we study the evolution of two spin entanglements in the one-dimensional Ising model in the transverse field. The system is initialized as the so-called thermal ground state of the pure Ising model. We investigate the evolution of the generation of entanglement with increasing magnetic field. We obtain that the derivative of the time at which the entanglement reaches its maximum with respect to the transverse field diverges at the critical point and its scaling behaviors versus the size of the system are the same as the static ground-state entanglement of the system.

  20. Low-Energy Electron Scattering by Sugarcane Lignocellulosic Biomass Molecules

    Science.gov (United States)

    Oliveira, Eliane; Sanchez, Sergio; Bettega, Marcio; Lima, Marco; Varella, Marcio

    2012-06-01

    The use of second generation (SG) bioethanol instead of fossil fuels could be a good strategy to reduce greenhouse gas emissions. However, the efficient production of SG bioethanol has being a challenge to researchers around the world. The main barrier one must overcome is the pretreatment, a very important step in SG bioethanol aimed at breaking down the biomass and facilitates the extraction of sugars from the biomass. Plasma-based treatment, which can generate reactive species, could be an interesting possibility since involves low-cost atmospheric-pressure plasma. In order to offer theoretical support to this technique, the interaction of low-energy electrons from the plasma with biomass is investigated. This study was motived by several works developed by Sanche et al., in which they understood that DNA damage arises from dissociative electron attachment, a mechanism in which electrons are resonantly trapped by DNA subunits. We will present elastic cross sections for low-energy electron scattering by sugarcane biomass molecules, obtained with the Schwinger multichannel method. Our calculations indicate the formation of π* shape resonances in the lignin subunits, while a series of broad and overlapping σ* resonances are found in cellulose and hemicellulose subunits. The presence of π* and σ* resonances could give rise to direct and indirect dissociation pathways in biomass. Then, theoretical resonance energies can be useful to guide the plasma-based pretreatment to break down specific linkages of interest in biomass.

  1. Low energy description of quantum gravity and complementarity

    International Nuclear Information System (INIS)

    Nomura, Yasunori; Varela, Jaime; Weinberg, Sean J.

    2014-01-01

    We consider a framework in which low energy dynamics of quantum gravity is described preserving locality, and yet taking into account the effects that are not captured by the naive global spacetime picture, e.g. those associated with black hole complementarity. Our framework employs a “special relativistic” description of gravity; specifically, gravity is treated as a force measured by the observer tied to the coordinate system associated with a freely falling local Lorentz frame. We identify, in simple cases, regions of spacetime in which low energy local descriptions are applicable as viewed from the freely falling frame; in particular, we identify a surface called the gravitational observer horizon on which the local proper acceleration measured in the observer's coordinates becomes the cutoff (string) scale. This allows for separating between the “low-energy” local physics and “trans-Planckian” intrinsically quantum gravitational (stringy) physics, and allows for developing physical pictures of the origins of various effects. We explore the structure of the Hilbert space in which the proposed scheme is realized in a simple manner, and classify its elements according to certain horizons they possess. We also discuss implications of our framework on the firewall problem. We conjecture that the complementarity picture may persist due to properties of trans-Planckian physics.

  2. Low energy nanoemulsification to design veterinary controlled drug delivery devices

    Directory of Open Access Journals (Sweden)

    Thierry F Vandamme

    2010-10-01

    Full Text Available Thierry F Vandamme, Nicolas Anton, University of Strasbourg, Faculty of Pharmacy, Illkirch Cedex, France; UMR CNRS 7199, Laboratoire de Conception et Application de Molécules Bioactives, équipe de Pharmacie Biogalénique, Illkirch Cedex, France,  This work is selected as Controlled Release Society Outstanding Veterinary Paper Award 2010Abstract: The unique properties of nanomaterials related to structural stability and quantum-scale reactive properties open up a world of possibilities that could be exploited to design and to target drug delivery or create truly microscale biological sensors for veterinary applications. We developed cost-saving and solvent-free nanoemulsions. Formulated with a low-energy method, these nanoemulsions can find application in the delivery of controlled amounts of drugs into the beverage of breeding animals (such as poultry, cattle, pigs or be used for the controlled release of injectable poorly water-soluble drugs.Keywords: nanoemulsion, nanomedicine, low-energy emulsification, veterinary, ketoprofen, sulfamethazine

  3. The low energy detector of Simbol-X

    Science.gov (United States)

    Lechner, P.; Andricek, L.; Briel, U.; Hasinger, G.; Heinzinger, K.; Herrmann, S.; Huber, H.; Kendziorra, E.; Lauf, T.; Lutz, G.; Richter, R.; Santangelo, A.; Schaller, G.; Schnecke, M.; Schopper, F.; Segneri, G.; Strüder, L.; Treis, J.

    2008-07-01

    Simbol-X is a French-Italian-German hard energy X-ray mission with a projected launch in 2014. Being sensitive in the energy range from 500 eV to 80 keV it will cover the sensitivity gap beyond the energy interval of today's telescopes XMM-Newton and Chandra. Simbol-X will use an imaging telescope of nested Wolter-I mirrors. To provide a focal length of 20 m it will be the first mission of two independent mirror and detector spacecrafts in autonomous formation flight. The detector spacecraft's payload is composed of an imaging silicon low energy detector in front of a pixelated cadmium-telluride hard energy detector. Both have a sensitive area of 8 × 8 cm2 to cover a 12 arcmin field of view and a pixel size of 625 × 625 μm2 adapted to the telescope's resolution of 20 arcsec. The additional LED specifications are: high energy resolution, high quantum efficiency, fast readout and optional window mode, monolithic device with 100 % fill factor and suspension mounting, and operation at warm temperature. To match these requirements the low energy detector is composed of 'active macro pixels', combining the large, scalable area of a Silicon Drift Detector and the low-noise, on-demand readout of an integrated DEPFET amplifier. Flight representative prototypes have been processed at the MPI semiconductor laboratory, and the prototype's measured performance demonstrates the technology readiness.

  4. Low energy electron point source microscopy: beyond imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Andre; Goelzhaeuser, Armin [Physics of Supramolecular Systems and Surfaces, University of Bielefeld, Postfach 100131, 33501 Bielefeld (Germany)

    2010-09-01

    Low energy electron point source (LEEPS) microscopy has the capability to record in-line holograms at very high magnifications with a fairly simple set-up. After the holograms are numerically reconstructed, structural features with the size of about 2 nm can be resolved. The achievement of an even higher resolution has been predicted. However, a number of obstacles are known to impede the realization of this goal, for example the presence of electric fields around the imaged object, electrostatic charging or radiation induced processes. This topical review gives an overview of the achievements as well as the difficulties in the efforts to shift the resolution limit of LEEPS microscopy towards the atomic level. A special emphasis is laid on the high sensitivity of low energy electrons to electrical fields, which limits the structural determination of the imaged objects. On the other hand, the investigation of the electrical field around objects of known structure is very useful for other tasks and LEEPS microscopy can be extended beyond the task of imaging. The determination of the electrical resistance of individual nanowires can be achieved by a proper analysis of the corresponding LEEPS micrographs. This conductivity imaging may be a very useful application for LEEPS microscopes. (topical review)

  5. Homestake result, sterile neutrinos, and low energy solar neutrino experiments

    Science.gov (United States)

    de Holanda, P. C.; Smirnov, A. Yu.

    2004-06-01

    The Homestake result is about ˜2σ lower than the Ar-production rate, QAr, predicted by the large mixing angle (LMA) Mikheyev-Smirnov-Wolfenstein solution of the solar neutrino problem. Also there is no apparent upturn of the energy spectrum (R≡Nobs/NSSM) at low energies in SNO and Super-Kamiokande. Both these facts can be explained if a light, Δm201˜(0.2 2)×10-5 eV2, sterile neutrino exists which mixes very weakly with active neutrinos: sin2 2α˜(10-5 10-3). We perform both the analytical and numerical study of the conversion effects in the system of two active neutrinos with the LMA parameters and one weakly mixed sterile neutrino. The presence of sterile neutrino leads to a dip in the survival probability in the intermediate energy range E=(0.5 5) MeV thus suppressing the Be, or/and pep, CNO, as well as B electron neutrino fluxes. Apart from diminishing QAr it leads to decrease of the Ge-production rate and may lead to the decrease of the BOREXINO signal as well as the CC/NC ratio at SNO. Future studies of the solar neutrinos by SNO, SK, BOREXINO, and KamLAND as well as by the new low energy experiments will allow us to check this possibility.

  6. New Mechanism of Low Energy Nuclear Reactions Using Superlow

    Science.gov (United States)

    Gareev, F. A.; Zhidkova, I. E.

    2006-03-01

    We proposed a new mechanism of LENR (low energy nuclear reactions) cooperative processes in the whole system - nuclei+atoms+condensed matter can occur at smaller threshold than the corresponding ones assoiciated with free constituents. The cooperative processes can be induced and enhanced by (``superlow energy'') external fields. The excess heat is the emission of internal energy, and transmutations from LENR are the result of redistribution of the internal energy of the whole system. A review of possible stimulation mechanisms of LENR is presented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the known fundamental physical laws: The universal resonance synchronization principle, and based on it, different enhancement mechanisms of reaction rates are responsible for these processes. The excitation and ionization of atoms may play the role of a trigger for LENR. F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0511092 v1 30 Nov 2005. F.A. Gareev, In: FPB-98, Novosibirsk, June 1998, p.92; F.A.Gareev, G.F. Gareeva, in: Novosibirsk, July 2000, p.161. F.A. Gareev, I.E. Zhidkova and Yu.L. Ratis, Preprint JINR P4-2004-68, Dubna, 2004. F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0505021 9 May 2005.

  7. Calculation and Measurement of Low-Energy Radiative Moller Scattering

    Science.gov (United States)

    Epstein, Charles; DarkLight Collaboration

    2017-09-01

    A number of current nuclear physics experiments have come to rely on precise knowledge of electron-electron (Moller) and positron-electron (Bhabha) scattering. Some of these experiments, having lepton beams on targets containing atomic electrons, use these purely-QED processes as normalization. In other scenarios, with electron beams at low energy and very high intensity, Moller scattering and radiative Moller scattering have such enormous cross-sections that the backgrounds they produce must be understood. In this low-energy regime, the electron mass is also not negligible in the calculation of the cross section. This is important, for example, in the DarkLight experiment (100 MeV). As a result, we have developed a new event generator for the radiative Moller and Bhabha processes, with new calculations that keep all terms of the electron mass. The MIT High Voltage Research Laboratory provides us a unique opportunity to study this process experimentally and compare it with our work, at a low beam energy of 2.5 MeV where the effects of the electron mass are significant. We are preparing a dedicated apparatus consisting of a magnetic spectrometer in order to directly measure this process. An overview of the calculation and the status of the experiment will be presented.

  8. Low energy probes of PeV scale sfermions

    Energy Technology Data Exchange (ETDEWEB)

    Altmannshofer, Wolfgang; Harnik, Roni; Zupan, Jure

    2013-11-27

    We derive bounds on squark and slepton masses in mini-split supersymmetry scenario using low energy experiments. In this setup gauginos are at the TeV scale, while sfermions are heavier by a loop factor. We cover the most sensitive low energy probes including electric dipole moments (EDMs), meson oscillations and charged lepton flavor violation (LFV) transitions. A leading log resummation of the large logs of gluino to sfermion mass ratio is performed. A sensitivity to PeV squark masses is obtained at present from kaon mixing measurements. A number of observables, including neutron EDMs, mu->e transitions and charmed meson mixing, will start probing sfermion masses in the 100 TeV-1000 TeV range with the projected improvements in the experimental sensitivities. We also discuss the implications of our results for a variety of models that address the flavor hierarchy of quarks and leptons. We find that EDM searches will be a robust probe of models in which fermion masses are generated radiatively, while LFV searches remain sensitive to simple-texture based flavor models.

  9. Dynamical black holes in low-energy string theory

    Energy Technology Data Exchange (ETDEWEB)

    Aniceto, Pedro [Departamento de Matemática, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Rocha, Jorge V. [Departament de Física Quàntica i Astrofísica, Institut de Ciències del Cosmos (ICCUB),Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain)

    2017-05-08

    We investigate time-dependent spherically symmetric solutions of the four-dimensional Einstein-Maxwell-axion-dilaton system, with the dilaton coupling that occurs in low-energy effective heterotic string theory. A class of dilaton-electrovacuum radiating solutions with a trivial axion, previously found by Güven and Yörük, is re-derived in a simpler manner and its causal structure is clarified. It is shown that such dynamical spacetimes featuring apparent horizons do not possess a regular light-like past null infinity or future null infinity, depending on whether they are radiating or accreting. These solutions are then extended in two ways. First we consider a Vaidya-like generalisation, which introduces a null dust source. Such spacetimes are used to test the status of cosmic censorship in the context of low-energy string theory. We prove that — within this family of solutions — regular black holes cannot evolve into naked singularities by accreting null dust, unless standard energy conditions are violated. Secondly, we employ S-duality to derive new time-dependent dyon solutions with a nontrivial axion turned on. Although they share the same causal structure as their Einstein-Maxwell-dilaton counterparts, these solutions possess both electric and magnetic charges.

  10. Low energy methods of molecular laser isotope separation

    International Nuclear Information System (INIS)

    Makarov, G N

    2015-01-01

    Of the many proposals to date for laser-assisted isotope separation methods, isotope-selective infrared (IR) multiphoton dissociation (MPD) of molecules has been the most fully developed. This concept served as the basis for the development and operation of the carbon isotope separation facility in Kaliningrad, Russia. The extension of this method to heavy elements, including uranium, is hindered by, among other factors, the high power consumption and the lack of high-efficiency high-power laser systems. In this connection, research and development covering low energy methods for the laser separation of isotopes (including those of heavy atoms) is currently in high demand. This paper reviews approaches to the realization of IR-laser-induced isotope-selective processes, some of which are potentially the basis on which low-energy methods for molecular laser isotope separation can be developed. The basic physics and chemistry, application potential, and strengths and weaknesses of these approaches are discussed. Potentially promising alternatives to the title methods are examined. (reviews of topical problems)

  11. Assessing risk from low energy radionuclide aerosol dispersal

    International Nuclear Information System (INIS)

    Waller, Edward; Perera, Sharman; Erhardt, Lorne; Cousins, Tom; Desrosiers, Marc

    2008-01-01

    Full text: When considering the potential dispersal of radionuclides into the environment, there are two broad classifications: explosive and non-explosive dispersal. An explosive dispersal relies on a violent and sudden release of energy, which may disrupt or vapourised any source containment. As such, the explosion provides the energy to both convert the source into a dispersable physical form and provides initial kinetic energy to transport the source away from the initiation point. This would be the case for sources of radiation in proximity to a steam or chemical explosion of high energy density. A low energy dispersal, on the other hand, may involve a lower energy initiator event (such as a fire or water spray) that transports particles into the near release zone, to be spread via wind or mechanical fields. For this type of dispersion to take place, the source must be in physical form ready for dispersal. In broad terms, this suggests either an ab initio powder form, or soluble/insoluble particulate form in a liquid matrix. This may be the case for radioactive material released from pressurized piping systems, material released through ventilation systems, or deliberate dispersals. To study aerosol dispersion of radionuclides and risk from low energy density initiators, there are a number of important parameters to consider. For example, particle size distribution, physicochemical form, atmospheric effects, charge effects, coagulation and agglomeration. At the University of Ontario Institute of Technology (UOIT) a unique small scale aerosol test chamber has been developed to study the low energy dispersal properties of a number of radioactive source simulant. Principle emphasis has been given to salts (CsCl and CoCl 2 ) and oxides (SrTiO 3 , CeO 2 and EuO 2 ). A planetary ball mill has been utilized to reduce particle size distributions when required. Particle sizing has been performed using Malvern Spraytec spray particle analyzers, cascade impactors, and

  12. Demonstration of low-energy district heating for low-energy buildings in EnergyFlexHouse. Subreport 1; Demonstration af lavenergifjernvarme til lavenergibyggeri i energyflexhouse. Delrapport 1

    Energy Technology Data Exchange (ETDEWEB)

    Holm Christiansen, C.

    2011-05-15

    This report concerns demonstration of a new concept for low temperature district heating to low energy buildings with district heating flow temperatures on just above 50 deg. C. The concept was developed in a previous energy research project under the EFP-2007-programme supported by the Danish Energy Agency. New types of prototypes for district heating consumer substations and district heating pipes in very small dimensions were developed and manufactured. Demonstration has been carried out in the Danish Technological Institute test houses 'EnergyFlexHouse' with the objective of analyzing and evaluating the performance of the concept in a real low energy house. The EnergyFlexHouse is actually two houses either each designed to be energy neutral with PV's but also fulfilling the Danish building codes low energy class 2015 requirements without the PV's. The two houses are called 'Lab' and 'Family' and are supplied with district heating from a small local distribution network. The tests are carried out in the 'Lab' house connected with a district heating branch twin pipe with two service pipes of just 10 mm inner diameter/14 mm outer diameter and with outer casing diameter of 110 mm corresponding to series 2 insulation. An accumulator consumer substation with a 175 liter storage tank on the primary side (district heating side) has been subject to tests. Tree different tapping patterns of domestic hot water were performed including tapping patterns based on the European standard PrEN50440. Generally the results show that balancing the primary loading flow in relation to actual tapping patterns and domestic hot water consumption is important in order to keep the district heating return temperature as low as possible. Based on the results different options are proposed in order to optimize the operation of the consumer substation. Recently a new project under the EUDP 2010-II has received grant to continue improving and

  13. Low energy, high power injection in JT-60 NBI

    International Nuclear Information System (INIS)

    Mizuno, Makoto; Dairaku, Masayuki; Horiike, Hiroshi

    1988-05-01

    JT-60 neutral beam injector (JT-60 NBI) is designed to inject 20 MW neutral hydrogen beam at energies of 70 ∼ 100 keV and the injection power decreases significantly at low energies (∼40 keV). For the extention of operation region aiming at the low density plasma heating and achieving H-mode by plasma periphery heating, increment of the injection power at low beam energies was required. The single-stage acceleration system was investigated in advance at the Prototype Injector Unit. From this result, the total injection power of 17 MW at 40 keV, 48 A per source was expected at the JT-60 NBI. This system was adopted in the JT-60 NBI from June, 1987 to July, 1987 and 17.6 MW neutral beam injection power was achieved. In the NB heating experiment, the H-mode transition phenomena was observed in JT-60 plasma. (author)

  14. The nuclear structure and low-energy reactions (NSLER) collaboration

    International Nuclear Information System (INIS)

    Dean, D J

    2006-01-01

    The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible

  15. Safety in design and operation of low energy particle accelerators

    International Nuclear Information System (INIS)

    Badawy, I.

    1991-01-01

    This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

  16. Development of a low energy neutral analyzer (LENA). Final report

    International Nuclear Information System (INIS)

    Curtis, C.C.; Fan, C.Y.; Hsieh, K.C.; McCullen, J.D.

    1986-05-01

    A low energy neutral particle analyzer (LENA) has been developed at the University of Arizona to detect particles originating in the edge plasma of fusion reactors. LENA was designed to perform energy analysis and measure flux levels of neutrals having energies between 5 and 50 eV (with possible extension to 500 eV neutrals), and do this with 1 to 10 ms time resolution. The instrument uses hot filaments to produce a 10 mA diffusion electron beam which ionizes incoming neutrals in a nearly field free region so that their velocity distribution is nearly undisturbed. The resultant ions are energy analyzed in a hyperbolic electrostatic analyzer, and detected by an MCP detector. LENA has been installed and operated on the ALCATOR C tokamak at the MIT Plasma Fusion Center. Results to date are discussed. At present, the LENA exhibits excessive sensitivity to the extremely high ultraviolet photon flux emanating from the plasma. Measures to correct this are suggested

  17. Radiation from silver films bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Chung, M.S.; Callcott, T.A.; Kretschmann, E.; Arakawa, E.T.

    1980-01-01

    Emission spectra from Ag films irradiated by low energy electrons (20-1500 eV) have been measured, and the results compared with theory. For relatively smooth films, two peaks in the spectra are resolved. One at 3.73 eV, the volume plasmon energy, is attributed to transition radiation and/or bremsstrahlung. The second, at about 3.60 eV, is very sensitive to surface roughness in both position and magnitude and is produced by roughness-coupled radiation from surface plasmons. For rough films, the roughness-coupled radiation dominates the emission. In addition to spectral shapes, the polarization of the radiation and its intensity as a function of electron energy were measured. The experimental results are compared with new calculations of roughness-coupled emission which account for most of our observations. They indicate that high wavevector roughness components play the dominant role in the emission process. (orig.)

  18. Elastic scattering of low-energy electrons with Sr atoms

    International Nuclear Information System (INIS)

    Yuan, J.; Zhang, Z.; Wan, H.

    1990-01-01

    Static-exchange, plus correlation-polarization-potential calculations are performed for elastic low-energy electron scattering from Sr atoms while paying attention to the low-lying shape resonances. The correlation potential is calculated both with and without a scaling factor. A 2 D-shape resonance is produced at 1.0 eV with a parameter-free, and at 1.25 eV with a scaled, correlation potential. No 2 P-shape resonances are predicted, but evidence to support the existence of a stable negative ion Sr - in the 5s 2 5p electron configuration is given from the viewpoint of electron scattering. The bound energy of the extra electron in the negative ion is estimated by transforming the phase shift of the corresponding partial wave into the polarization quantum-defect number and extrapolating the number from positive to negative energies

  19. Confab - Systematic generation of diverse low-energy conformers

    Directory of Open Access Journals (Sweden)

    O'Boyle Noel M

    2011-03-01

    Full Text Available Abstract Background Many computational chemistry analyses require the generation of conformers, either on-the-fly, or in advance. We present Confab, an open source command-line application for the systematic generation of low-energy conformers according to a diversity criterion. Results Confab generates conformations using the 'torsion driving approach' which involves iterating systematically through a set of allowed torsion angles for each rotatable bond. Energy is assessed using the MMFF94 forcefield. Diversity is measured using the heavy-atom root-mean-square deviation (RMSD relative to conformers already stored. We investigated the recovery of crystal structures for a dataset of 1000 ligands from the Protein Data Bank with fewer than 1 million conformations. Confab can recover 97% of the molecules to within 1.5 Å at a diversity level of 1.5 Å and an energy cutoff of 50 kcal/mol. Conclusions Confab is available from http://confab.googlecode.com.

  20. Automorphic properties of low energy string amplitudes in various dimensions

    International Nuclear Information System (INIS)

    Green, Michael B.; Russo, Jorge G.; Vanhove, Pierre

    2010-01-01

    This paper explores the moduli-dependent coefficients of higher-derivative interactions that appear in the low-energy expansion of the four-supergraviton amplitude of maximally supersymmetric string theory compactified on a d torus. These automorphic functions are determined for terms up to order ∂ 6 R 4 and various values of d by imposing a variety of consistency conditions. They satisfy Laplace eigenvalue equations with or without source terms, whose solutions are given in terms of Eisenstein series, or more general automorphic functions, for certain parabolic subgroups of the relevant U-duality groups. The ultraviolet divergences of the corresponding supergravity field theory limits are encoded in various logarithms, although the string theory expressions are finite. This analysis includes intriguing representations of SL(d) and SO(d,d) Eisenstein series in terms of toroidally compactified one and two-loop string and supergravity amplitudes.

  1. A New Instrument Design for Imaging Low Energy Neutral Atoms

    Science.gov (United States)

    Keller, John W.; Collier, Michael R.; Chornay, Dennis; Rozmarynowski, Paul; Getty, Stephanie; Cooper, John F.; Smith, Billy

    2007-01-01

    The MidSTAR-2 satellite, to be built at the US Naval Academy as a follow-on to the successful MidSTAR-1 satellite (http://web.ew.usna.edu/midstar/), will launch in 2011 and carry three Goddard Space Flight Center (GSFC) experiments developed under Goddard's Internal Research and Development (IRAD) program. One of these GSFC instruments, the Miniature Imager for Neutral Ionospheric atoms and Magnetospheric Electrons (MINI-ME) builds on the heritage of the Goddard-developed Low-Energy Neutral Atom (LENA) imager launched on the IMAGE spacecraft in 2000. MINI-ME features a Venetian-blind conversion surface assembly that improves both light rejection and conversion efficiency in a smaller and lighter package than LENA making this an highly effective instrument for viewing solar wind charge exchange with terrestrial and planetary exospheres. We will describe the MINI-ME prototyping effort and its science targets.

  2. Simulation of a low energy beam transport line

    International Nuclear Information System (INIS)

    Yang Yao; Liu Zhanwen; Zhang Wenhui; Ma Hongyi; Zhang Xuezhen; Zhao Hongwei; Yao Ze'en

    2012-01-01

    A 2.45 GHz electron cyclotron resonance intense proton source and a low energy beam transport line with dual-Glaser lens were designed and fabricated by Institute of Modern Physics for a compact pulsed hadron source at Tsinghua. The intense proton beams extracted from the ion source are transported through the transport line to match the downstream radio frequency quadrupole accelerator. Particle-in-cell code BEAMPATH was used to carry out the beam transport simulations and optimize the magnetic field structures of the transport line. Emittance growth due to space charge and spherical aberrations of the Glaser lens were studied in both theory and simulation. The results show that narrow beam has smaller aberrations and better beam quality through the transport line. To better match the radio frequency quadrupole accelerator, a shorter transport line is desired with sufficient space charge neutralization. (authors)

  3. A simulation of low energy channeling of protons in silicon

    International Nuclear Information System (INIS)

    Sabin, J.R.

    1994-01-01

    The authors present early results from the CHANNEL code, which simulates the passage of ionized projectiles through bulk solids. CHANNEL solves the classical equations of motion for the projectile using the force obtained from the gradient of the quantum mechanically derived coulombic potential of the solid (determined via a full potential augmented plane wave FLAPW calculation on the bulk) and a quantum mechanical energy dissipation term, the stopping power, as determined from the local electron density, using the method of Echenique, Nieminen, and Ritchie. The code then generates the trajectory of the ionic projectile for a given initial velocity and a given incident position on the unit cell face. For each incident projectile velocity, the authors generate trajectories for incidence distributed over the channel face. The distribution of ranges generates an implantation profile. In this paper, they report ion (proton) implantation profiles for low energy protons with initial velocity along the (100) and (110) channel directions of diamond structured Silicon

  4. The quasi deuteron model for low energy pion absorption

    International Nuclear Information System (INIS)

    Gouweloos, M.

    1986-01-01

    In this thesis pion absorption in complex nuclei is studied in the quasi-deuteron model in which the pion is absorbed on a nucleon pair in the nucleus. The mechanism is studied in the low-energy domain since then the in-medium (pi→NN) operator turns out to be of simple character. In Ch. 2 and 3 this operator is constructed and analytical expressions are derived for (pi,NN) distributions in a plane wave impulse approximation for nuclei. The results turn out to be very useful for developing insight in the possibilities inherent in the QDM and the interpretation of the results in later chapters. Ch. 4 to 6 are devoted to the more realistic distorted wave calculations. In Ch. 4 the formal framework is presented and the calculational details are discussed. Ch.5 and 6 contain the comparison to stopped pion and in-flight data respectively. In Ch. 7 the main results are summarized. (Auth.)

  5. Elastic positron-cadmium scattering at low energies

    International Nuclear Information System (INIS)

    Bromley, M. W. J.; Mitroy, J.

    2010-01-01

    The elastic and annihilation cross sections for positron-cadmium scattering are reported up to the positronium-formation threshold (at 2.2 eV). The low-energy phase shifts for the elastic scattering of positrons from cadmium were derived from the bound and pseudostate energies of a very large basis configuration-interaction calculation of the e + -Cd system. The s-wave binding energy is estimated to be 126±42 meV, with a scattering length of A scat =(14.2±2.1)a 0 , while the threshold annihilation parameter, Z eff , was 93.9±26.5. The p-wave phase shift exhibits a weak shape resonance that results in a peak Z eff of 91±17 at a collision energy of about 490±50 meV.

  6. Measurements of sputtering yields for low-energy plasma ions

    International Nuclear Information System (INIS)

    Nishi, M.; Yamada, M.; Suckewer, S.; Rosengaus, E.

    1979-04-01

    Sputtering yields of various wall/limiter materials of fusion devices have been extensively measured in the relevant plasma environment for low-energy light ions (E 14 cm -3 and electron temperature up to 10eV. Target materials used were C (graphite), Ti, Mo, Ta, W, and Fe (stainless steel). In order to study the dependence of the sputtering yields on the incident energy of ions, the target samples were held at negative bias voltage up to 300V. The sputtering yields were determined by a weight-loss method and by spectral line intensity measurements. The data obtained in the present experiment agree well with those previously obtained at the higher energies (E greater than or equal to 200eV) by other authors using different schemes; the present data also extend to substantially lower energies (E approx. > 30eV) than hitherto

  7. Degradation of carrageenan by low energy electron accelerator

    International Nuclear Information System (INIS)

    Relleve, L.; Aranilla, C.; Abad, L.; Dela Rosa, A.; Nagasawa, Naotsugu; Yagi, Toshiaki; Kume, Tamikazu; Yoshii, Fumio

    2004-01-01

    Degradation of κ-carrageenan using vessel-type low energy electron accelerator was investigated. Carrageenan with different molecular weights were obtained from irradiation of high molecular weight (HMW) and low molecular weight (LMW) κ-carrageenan. Other results presented were obtained from degradation studies of carrageenan by gamma rays. The decrease in molecular weight was accompanied by partial desulfation. From comparison of radiation degradation yield (Gd), it was found that the susceptibility to radiation of the three types of carrageenans in aqueous/gel forms follows the order of λ->ι->>κ- and could have been influenced by their conformational state. κ-carrageenan with molecular weight of ca. 10,000 showed strong growth promotion effect for potato in tissue culture. (author)

  8. The low-energy frontier of particle physics

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2010-02-01

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  9. A theory of low energy π-3He elastic scattering

    International Nuclear Information System (INIS)

    Geffen, F.M.M. van.

    1991-01-01

    The main aim of this work is the construction of a first-order optical potential for the scattering of pions by 3 He at low energy with as few approximations as possible. In particular the Fermi motion is treated extremely carefully by using microscopic 3 He wave functions and by performing the complete Fermi-integral. Differential cross-sections and analyzing powers have been calculated. In a detailed comparison between the first-order optical with one which results from using the semi-factored approximation, it became clear that the latter has the following shortcomings: 1. the dependence of the subenergy on the pion-nucleus scattering angle, and 2. the independence of this energy on the relative motion of the spectator nucleons. (author). 101 refs.; 15 figs.; 3 tabs

  10. Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

    Science.gov (United States)

    Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

    2017-07-28

    We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

  11. Medipix 2 detector applied to low energy electron microscopy

    International Nuclear Information System (INIS)

    Gastel, R. van; Sikharulidze, I.; Schramm, S.; Abrahams, J.P.; Poelsema, B.; Tromp, R.M.; Molen, S.J. van der

    2009-01-01

    Low energy electron microscopy (LEEM) and photo-emission electron microscopy (PEEM) traditionally use microchannel plates (MCPs), a phosphor screen and a CCD-camera to record images and diffraction patterns. In recent years, however, MCPs have become a limiting factor for these types of microscopy. Here, we report on a successful test series using a solid state hybrid pixel detector, Medipix 2, in LEEM and PEEM. Medipix 2 is a background-free detector with an infinite dynamic range, making it very promising for both real-space imaging and spectroscopy. We demonstrate a significant enhancement of both image contrast and resolution, as compared to MCPs. Since aging of the Medipix 2 detector is negligible for the electron energies used in LEEM/PEEM, we expect Medipix to become the detector of choice for a new generation of systems.

  12. Medipix 2 detector applied to low energy electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gastel, R. van, E-mail: R.vanGastel@utwente.nl [University of Twente, MESA Institute for Nanotechnology, P.O. Box 217, NL-7500 AE Enschede (Netherlands); Sikharulidze, I. [Leiden University, Leiden Institute of Chemistry, P.O. Box 9502, NL-2300 RA Leiden (Netherlands); Schramm, S. [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands); Abrahams, J.P. [Leiden University, Leiden Institute of Chemistry, P.O. Box 9502, NL-2300 RA Leiden (Netherlands); Poelsema, B. [University of Twente, MESA Institute for Nanotechnology, P.O. Box 217, NL-7500 AE Enschede (Netherlands); Tromp, R.M. [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands); IBM Research Division, T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598 (United States); Molen, S.J. van der [Leiden University, Kamerlingh Onnes Laboratorium, P.O. Box 9504, NL-2300 RA Leiden (Netherlands)

    2009-12-15

    Low energy electron microscopy (LEEM) and photo-emission electron microscopy (PEEM) traditionally use microchannel plates (MCPs), a phosphor screen and a CCD-camera to record images and diffraction patterns. In recent years, however, MCPs have become a limiting factor for these types of microscopy. Here, we report on a successful test series using a solid state hybrid pixel detector, Medipix 2, in LEEM and PEEM. Medipix 2 is a background-free detector with an infinite dynamic range, making it very promising for both real-space imaging and spectroscopy. We demonstrate a significant enhancement of both image contrast and resolution, as compared to MCPs. Since aging of the Medipix 2 detector is negligible for the electron energies used in LEEM/PEEM, we expect Medipix to become the detector of choice for a new generation of systems.

  13. New directions in low energy electron molecule collision calculations

    International Nuclear Information System (INIS)

    Burke, P.G.; Noble, C.J.

    1982-01-01

    New theoretical and computational methods for studying low energy electron molecule collisions are discussed. Having considered the fixed-nuclei approximation and the form of the expansion of the total collision wavefunction, the various approximations which have been made are examined, including the static plus model exchange approximation, the static exchange approximation and the close coupling approximation, particular attention being paid to methods of including the molecular charge polarisation. Various ways which have been developed to solve the resultant equations are discussed and it is found that there is increasing emphasis being given to methods which combine the advantages of discrete multi-centre analytic bases with single centre numerical bases. (U.K.)

  14. Does the effective Lagrangian for low-energy QCD scale?

    International Nuclear Information System (INIS)

    Birse, M.C.

    1994-01-01

    Quantum chromodynamics is not an approximately scale-invariant theory. Hence a dilaton field is not expected to provide a good description of the low-energy dynamics associated with the gluon condensate. Even if such a field is introduced, it remains almost unchanged in hadronic matter at normal densities. This is because the large glueball mass together with the size of the phenomenological gluon condensate ensure that changes to that condensate are very small at such densities. Any changes in hadronic masses and decay constants in matter generated by that condensate will be much smaller than those produced directly by changes in the quark condensate. Hence, masses and decay constants are not expected to display a universal scaling. (author)

  15. B meson mixing and low-energy dynamical flavour

    International Nuclear Information System (INIS)

    Chkareuli, J.L.

    1990-01-01

    The low-energy quantum flavour dynamics offered by the local horizontal symmetry SU(3) H for quark-lepton families is presented in some detail. It is shown that spontaneous breaking of this symmetry naturally leads to the simple Fritzsch ansatz for the quark mass matrices and simultaneously provides the observed magnitude of B d 0 -anti B d 0 mixing without any appreciable perturbation of the K 0 -anti K 0 system. This mixing determines a real scale for the masses of the SU(3) H gauge bosons. In marked contrast to the standard model this new approach is certain to give rise to small B s 0 -anti B s 0 mixing and large D 0 -anti D 0 mixing that can be of real interest in the near future. (orig.)

  16. Cost analysis of low energy electron accelerator for film curing

    International Nuclear Information System (INIS)

    Ochi, Masafumi

    2003-01-01

    Low energy electron accelerators are recognized as one of the advanced curing means of converting processes for films and papers. In the last three years the price of the accelerator equipment has been greatly reduced. The targeted application areas are mainly processes of curing inks, coatings, and adhesives to make packaging materials. The operating cost analyses were made for electron beam (EB) processes over the conventional ones without EB. Then three new proposals for cost reduction of EB processes are introduced. Also being developed are new EB chemistries such as coatings, laminating adhesives and inks. EB processes give instantaneous cure and EB chemistries are basically non solvent causing less VOC emission to the environment. These developments of both equipment and chemistries might have a potential to change conventional packaging film industries. (author)

  17. Very low-energy hydrogen-antihydrogen scattering

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Chamberlain, C.W.

    2003-01-01

    In view of current interest in the trapping of antihydrogen (H-bar) atoms at very low temperatures, we have carried out a calculation of s-wave hydrogen-antihydrogen scattering at very low energies, using the Kohn variational method, taking into account rearrangement scattering into the three channels that contain positronium in its ground state and lie closest to threshold. We find that our values for the elastic cross section are in good agreement with the values obtained by Jonsell et al. [2001 Phys. Rev. A 64 052712] using a distorted wave approximation. However, our values for the total rearrangement cross section are much larger than their values and we predict that cooling of H-bar by cold H would be considerably less efficient than was found to be the case by Jonsell et al.. (author)

  18. New results for single stage low energy carbon AMS

    International Nuclear Information System (INIS)

    Klody, G.M.; Schroeder, J.B.; Norton, G.A.; Loger, R.L.; Kitchen, R.L.; Sundquist, M.L.

    2005-01-01

    A new configuration of the NEC single stage, low energy carbon AMS system (U.S. Patent 6,815,666 B2) has been built and tested. The injector includes two 40-sample ion sources, electrostatic and magnetic analysis, and fast sequential injection. The gas stripper, analyzing magnet, electrostatic analyzer, and detector are on an open air 250 kV deck. Both 12 C and 13 C currents are measured on the deck after the stripper, and an SSB detector is used for 14 C counting. Injected 12 C and mass 13 ( 13 C and 12 CH) currents are also measured. Automated controls follow a user-specified run list for unattended operation. Initial test results show precision for 14 C/ 12 C ratios of better than 5 per mil, and backgrounds for unprocessed graphite of less than 0.005 x modern. We will report final results for precision, background, and throughput and discuss related design features

  19. Analysis of parity violating nuclear effects at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Desplanques, B; Missimer, J [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

    1978-05-15

    The authors present an analysis of parity-violating nuclear effects at low energy which attempts to circumvent the uncertainties due to the weak and strong nucleon-nucleon interactions at short distances. Extending Danilov's parametrization of the parity-violating nucleon-nucleon scattering amplitude, they introduce six parameters: one for the long-range contribution due to the pion exchange and five for the shorter-range contributions. This choice gives an accurate representation of parity-violating effects in the nucleon-nucleon system up to a lab energy of 75 MeV. For calculations in nuclei, an effective two-body potential is derived in terms of the parameters. The analysis of presently measured effects shows that they are consistent, and, in particular, that the circular polarization of photons in n + p ..-->.. d + ..gamma.. is not incompatible with the other measurements. It does not imply a dominant isotensor component.

  20. The reactor antineutrino anomaly and low energy threshold neutrino experiments

    Science.gov (United States)

    Cañas, B. C.; Garcés, E. A.; Miranda, O. G.; Parada, A.

    2018-01-01

    Short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. In this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. We discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. We find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. We also analyze the measurements of antineutrino scattering off electrons from short distance reactor experiments. In this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the Gallium anomaly.

  1. Auger vs resonance neutralization in low energy He+ ion scattering

    International Nuclear Information System (INIS)

    Woodruff, D.P.

    1983-01-01

    He + ions incident on a metal surface can neutralize either by an Auger or resonant charge exchange. While the Auger process has always been thought to be dominant, recent theoretical interest in the simpler one-electron resonance process has led to suggestions that this alone can account for the neutralization seen in low energy He + ion scattering. In this paper this assertion is analysed by looking at the wider information available on charge exchange processes for He + ion scattering through comparison with Li + ion scattering, the importance of multiple scattering in both these scattering experiments and the results of ion neutralization spectroscopy. These lead to the conclusion that while resonance neutralization to produce metastable He* may well occur at a substantial rate in He + ion scattering, the dominant process leading to loss of ions from the final scattered signal is Auger neutralization as originally proposed. (author)

  2. Linac4 Low Energy Beam Measurements with Negative Hydrogen

    CERN Document Server

    Scrivens, R; Crettiez, O; Dimov, V; Gerard, D; Granemann Souza, E; Guida, R; Hansen, J; Lallement, J B; Lettry, J; Lombardi, A; Midttun, O; Pasquino, C; Raich, U; Riffaud, B; Roncarolo, F; Valerio-Lizarraga, C A; Wallner, J; Yarmohammadi Satri, M; Zickler, T

    2014-01-01

    Linac4, a 160 MeV normal-conducting H- linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H- beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  3. Further evidence for low-energy protonium production in vacuum

    CERN Document Server

    Lodi Rizzini, E; Zurlo, N; Charlton, M; Amsler, C; Bonomi, G; Canali, C; Carraro, C; Fontana, A; Genova, P; Hayano, R; Jorgensen, L V; Kellerbauer, A; Lagomarsino, V; Landua, R; Macri, M; Manuzio, G; Montagna, P; Regenfus, C; Rotondi, A; Testera, G; Variola, A; van der Werf, D P

    2012-01-01

    We describe an experiment performed in the ATHENA apparatus in which there is evidence that the antiproton-proton bound state, protonium, has been produced at very low energies in vacuum following the interaction of cold antiprotons with a trapped cloud of molecular hydrogen ions. The latter were confined in a centrifugally separated belt outside a positron plasma used for antihydrogen formation. Studies have been performed at low positron plasma temperatures in which the protonium annihilation signal has been identified along with that from antihydrogen, and we discuss how their contributions can be disentangled. With the positron plasma heated to around 10000 K the ions become distributed in the positrons, and the majority of the annihilation signal can be explained in terms of protonium formation, as antihydrogen creation is heavily suppressed. In this case we compare the observed protonium formation rate with expectations from theory and find reasonable accord, when experimental systematics are taken into...

  4. Precocious scaling in antiproton-proton scattering at low energies

    International Nuclear Information System (INIS)

    Ion, D.B.; Petrascu, C.; Topor Pop, V.; Popa, V.

    1993-08-01

    The scaling of the diffraction peak in antiproton-proton scattering has been investigated from nera threshold up to 3 GeV/c laboratory momenta. It was shown that the scaling of the differential cross sections are evidentiated with a surprising accuracy not only at high energies, but also at very low ones (e.g. p LAB = 0.1 - 0.5 GeV/c), beyond the resonance and exotic resonance regions. This precocious scaling strongly suggests that the s-channel helicity conservation (SCHC) can be a peculiar property that should be tested in antiproton-proton interaction not only at high energies but also at low energy even below p LAB = 1 GeV/c. (author). 36 refs, 9 figs

  5. New development for low energy electron beam processor

    International Nuclear Information System (INIS)

    Takei, Taro; Goto, Hitoshi; Oizumi, Matsutoshi; Hirakawa, Tetsuya; Ochi, Masafumi

    2003-01-01

    Newly developed low-energy electron beam (EB) processors that have unique designs and configurations compared to conventional ones enable electron-beam treatment of small three-dimensional objects, such as grain-like agricultural products and small plastic parts. As the EB processor can irradiate the products from the whole angles, the uniform EB treatment can be achieved at one time regardless the complex shapes of the product. Here presented are two new EB processors: the first system has cylindrical process zone, which allows three-dimensional objects to be irradiated with one-pass treatment. The second is a tube-type small EB processor, achieving not only its compactor design, but also higher beam extraction efficiency and flexible installation of the irradiation heads. The basic design of each processor and potential applications with them will be presented in this paper. (author)

  6. Pion-nucleon interactions in low energy region

    International Nuclear Information System (INIS)

    Hiroshige, Noboru; Tsujimura, Tadakuni.

    1977-01-01

    Pion-nucleon interactions in low energy region (below 320 MeV in kinetic energy) are investigated on the basis of the one-particle-exchange model. The model is directly compared with the experimental data, i.e., differential cross sections and recoil nucleon polarizations, since phase shifts have not been uniquely determined. It is shown that these experimental data can be well reproduced by taking account of N (nucleon), Δ 33 , N 11 , N 13 , rho, f 0 and S (scalar meson) in the intermediate state. Some comments are given on the coupling constants which are determined so as to minimize chi-squared value (chi 2 ). Our predicted phase shifts for s-, p- and d-waves are also compared with other authors'. (auth.)

  7. Opportunistic Sensor Data Collection with Bluetooth Low Energy

    Directory of Open Access Journals (Sweden)

    Sergio Aguilar

    2017-01-01

    Full Text Available Bluetooth Low Energy (BLE has gained very high momentum, as witnessed by its widespread presence in smartphones, wearables and other consumer electronics devices. This fact can be leveraged to carry out opportunistic sensor data collection (OSDC in scenarios where a sensor node cannot communicate with infrastructure nodes. In such cases, a mobile entity (e.g., a pedestrian or a vehicle equipped with a BLE-enabled device can collect the data obtained by the sensor node when both are within direct communication range. In this paper, we characterize, both analytically and experimentally, the performance and trade-offs of BLE as a technology for OSDC, for the two main identified approaches, and considering the impact of its most crucial configuration parameters. Results show that a BLE sensor node running on a coin cell battery can achieve a lifetime beyond one year while transferring around 10 Mbit/day, in realistic OSDC scenarios.

  8. Opportunistic Sensor Data Collection with Bluetooth Low Energy.

    Science.gov (United States)

    Aguilar, Sergio; Vidal, Rafael; Gomez, Carles

    2017-01-23

    Bluetooth Low Energy (BLE) has gained very high momentum, as witnessed by its widespread presence in smartphones, wearables and other consumer electronics devices. This fact can be leveraged to carry out opportunistic sensor data collection (OSDC) in scenarios where a sensor node cannot communicate with infrastructure nodes. In such cases, a mobile entity (e.g., a pedestrian or a vehicle) equipped with a BLE-enabled device can collect the data obtained by the sensor node when both are within direct communication range. In this paper, we characterize, both analytically and experimentally, the performance and trade-offs of BLE as a technology for OSDC, for the two main identified approaches, and considering the impact of its most crucial configuration parameters. Results show that a BLE sensor node running on a coin cell battery can achieve a lifetime beyond one year while transferring around 10 Mbit/day, in realistic OSDC scenarios.

  9. Bluetooth low energy: wireless connectivity for medical monitoring.

    Science.gov (United States)

    Omre, Alf Helge

    2010-03-01

    Electronic wireless sensors could cut medical costs by enabling physicians to remotely monitor vital signs such as blood pressure, blood glucose, and blood oxygenation while patients remain at home. According to the IDC report "Worldwide Bluetooth Semiconductor 2008-2012 Forecast," published November 2008, a forthcoming radio frequency communication ("wireless connectivity") standard, Bluetooth low energy, will link wireless sensors via radio signals to the 70% of cell phones and computers likely to be fitted with the next generation of Bluetooth wireless technology, leveraging a ready-built infrastructure for data transmission. Analysis of trends indicated by this data can help physicians better manage diseases such as diabetes. The technology also addresses the concerns of cost, compatibility, and interoperability that have previously stalled widespread adoption of wireless technology in medical applications. (c) 2010 Diabetes Technology Society.

  10. Linac4 low energy beam measurements with negative hydrogen ions

    Energy Technology Data Exchange (ETDEWEB)

    Scrivens, R., E-mail: richard.scrivens@cern.ch; Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T. [CERN, 1211 Geneva 23 (Switzerland)

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  11. Search for low Energy solar Axions with CAST

    CERN Document Server

    Cantatore, Giovanni; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Boydag, F.S.; Brauninger, H.; Cantatore, G.; Carmona, J.M.; Cebrian, S.; Cetin, S.A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O.B.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Franz, J.; Galan, J.; Gazis, E.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, F.H.; Hikmet, I.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Karageorgopoulou, T.; Karuza, M.; Konigsmann, Kay; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lozza, V.; Lutz, G.; Luzon, G.; Miller, D.; Morales, A.; Morales, J.; Niinikoski, T.; Nordt, A.; Ortiz, A.; Papaevangelou, T.; Pivovaroff, M.; Placci, A.; Raiteri, G.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Solanki, S.K.; Soufli, R.; Stewart, L.; Tsagri, M.; van Bibber, K.; Villar, J.; Vogel, J.; Walckiers, L.; Zioutas, K.

    2008-01-01

    We have started the development of a detector system, sensitive to single photons in the eV energy range, to be suitably coupled to one of the CAST magnet ports. This system should open to CAST a window on possible detection of low energy Axion Like Particles emitted by the sun. Preliminary tests have involved a cooled photomultiplier tube coupled to the CAST magnet via a Galileian telescope and a switched 40 m long optical fiber. This system has reached the limit background level of the detector alone in ideal conditions, and two solar tracking runs have been performed with it at CAST. Such a measurement has never been done before with an axion helioscope. We will present results from these runs and briefly discuss future detector developments.

  12. Manipulation of rare isotope beams - from high to low energies

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States)], E-mail: bollen@nscl.msu.edu; Campbell, C.; Chouhan, S.; Guenaut, C.; Lawton, D.; Marti, F. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Ottarson, J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Pang, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Department of Chemistry, Michigan State University, East Lansing, MI (United States); Schwarz, S.; Zeller, A.F.; Zavodszky, P. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States)

    2008-10-15

    Projectile fragmentation above 50 MeV/u and in-flight separation is a powerful technique for the production and delivery of rare isotopes. The production is fast and chemistry independent, providing nuclides far away from the valley of beta stability and for a very large range of elements. These benefits can be maximized if the produced rare isotopes are made available also as low-energy beams (<15 MeV/u) and at rest. For this purpose the fast beams need to be slowed down and thermalized before being re-accelerated to the desired energy. This can be achieved with gas stopping techniques. This paper discusses various aspects of stopping fast rare isotope beams, including the development of a 'cyclotron gas stopper' that promises to overcome the limitations of present linear gas stopping schemes.

  13. Low Energy Reaction cell for advanced space power applications

    International Nuclear Information System (INIS)

    Miley, George H.; Rice, Eric

    2001-01-01

    Power units using Low Energy Reactions (LENRs) are under study as a radical new approach to power units that could potentially replace nuclear and chemical power sources for a number of space applications. These cells employ thin metallic films (order of 500 deg., using variously Ni, Pd and Ti) as cathodes with various electrolytes such as 0.5-1 molar lithium sulfate in light water. Power densities exceeding 10 W/cm3 in the thin-films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies ∼20% of the total cell volume. If this is achieved, overall power densities of ∼20 W/cm3 appear feasible, opening the way to a number of potential applications ranging from distributed power units in spacecraft to advanced propulsion

  14. Five low energy phosphorene allotropes constructed through gene segments recombination.

    Science.gov (United States)

    He, Chaoyu; Zhang, ChunXiao; Tang, Chao; Ouyang, Tao; Li, Jin; Zhong, Jianxin

    2017-04-27

    Based on the crystal structures of the previously proposed low energy η-P and θ-P, five new phosphorene allotropes were predicted through gene segments recombination method. These five new phosphorene allotropes are confirmed dynamically stable and energetically more favorable than their parents (η-P and θ-P). Especially, the XX-XX type G1-P is confirmed energetically more favorable than most of all the previously proposed phosphorene allotropes, including black phosphorene and blue phosphorene, which is highly expected to be synthesized in future experiment through vapor deposition or epitaxial growth method like blue β-P. The calculated results also show that such a new promising phosphorene allotrope G1-P is a potential candidate for application in nano-electronics according to its middle band gap of about 1.491 eV from DFT-HSE06 calculation.

  15. The nucleon-antinucleon interaction at low energies

    International Nuclear Information System (INIS)

    Alvear, C.

    1977-08-01

    A theoretical analysis is made of recent low energy data relative to scattering process p sup(-)d → p + pions from 300 to 600 Mev/c laboratory incident momentum, with the purpose of obtaining information about resonances in the pure iso-spin system p sup(-)n (I = 1). The single and double term of the multiple scattering series are evaluated using a formalism based on Glauber theory and Feynman rules. Then, the differential cross section with respect to the invariant mass of the produced pions is obtained. The theoretical results are used to analyse the available data, which are then shown to be consistent with a non resonant behavior of the p sup(-)n system. (Author) [pt

  16. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    In the future energy system a considerable increase in the penetration of renewable energy is expected, challenging the stability of the system, as both production and consumption will have fluctuating patterns. Hence, the concept of energy flexibility will be necessary in order for the consumption...... to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study...... the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...

  17. Low energy current accumulator for high-energy proton rings

    International Nuclear Information System (INIS)

    Month, M.

    1977-01-01

    Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum

  18. Low-energy photo- and electroproduction for physical pions

    International Nuclear Information System (INIS)

    MacMullen, J.T.

    1979-02-01

    The background resonance Δ(1230), Nsup(*)(1520), Nsup(*)(1470) and Nsup(*)(1535)pion and axial-vector amplitudes are first calculated in the soft pion and on-shell configuration, respectively. Then a comparison is made with the usual soft pion theorems and on-shell low-energy expansions of current algebra as worked out in the previous paper. The agreement is good and we also deduce a nucleon dipole form factor axial-vector mass of msub(A)approximately equal to 1,23 GeV. Finally an approximate value for the non-strange current quark mass of m equal to 0,64 +- 1,11μ is extracted from the data

  19. Low-energy house in Sisimiut - Measurement equipment

    Energy Technology Data Exchange (ETDEWEB)

    Hvidthoeft Delff Andersen, P.; Rode, C.; Madsen, Henrik

    2013-08-15

    This paper documents the measurement equipment in a low-energy house in Sisimiut, Greenland. Detailed measurements are being taken on energy consumption, indoor temperatures, floor heating, ventilation, open/closed state of doors and windows, and indoors climate. Equipped with a central control unit, experiments can be designed in order to study heat dynamics of the building. It is described how to plan and execute such experiments in one apartment in the building. The building also features both a solar thermal system and extra buffer tank facilitating testing of storage strategies on the power generated by the solar thermal system. A weather station equipped with thermometer, pyranometer and anemometer is installed on the building as well. Finally, it is described how to retrieve data from an SQL server which is configured to take monthly backups. R functions have been implemented to fetch and prepare the data for time series analysis. Examples are given on the use of these. (Author)

  20. Geometric low-energy effective action in a doubled spacetime

    Science.gov (United States)

    Ma, Chen-Te; Pezzella, Franco

    2018-05-01

    The ten-dimensional supergravity theory is a geometric low-energy effective theory and the equations of motion for its fields can be obtained from string theory by computing β functions. With d compact dimensions, an O (d , d ; Z) geometric structure can be added to it giving the supergravity theory with T-duality manifest. In this paper, this is constructed through the use of a suitable star product whose role is the one to implement the weak constraint on the fields and the gauge parameters in order to have a closed gauge symmetry algebra. The consistency of the action here proposed is based on the orthogonality of the momenta associated with fields in their triple star products in the cubic terms defined for d ≥ 1. This orthogonality holds also for an arbitrary number of star products of fields for d = 1. Finally, we extend our analysis to the double sigma model, non-commutative geometry and open string theory.

  1. Hierarchical fuzzy control of low-energy building systems

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhen; Dexter, Arthur [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom)

    2010-04-15

    A hierarchical fuzzy supervisory controller is described that is capable of optimizing the operation of a low-energy building, which uses solar energy to heat and cool its interior spaces. The highest level fuzzy rules choose the most appropriate set of lower level rules according to the weather and occupancy information; the second level fuzzy rules determine an optimal energy profile and the overall modes of operation of the heating, ventilating and air-conditioning system (HVAC); the third level fuzzy rules select the mode of operation of specific equipment, and assign schedules to the local controllers so that the optimal energy profile can be achieved in the most efficient way. Computer simulation is used to compare the hierarchical fuzzy control scheme with a supervisory control scheme based on expert rules. The performance is evaluated by comparing the energy consumption and thermal comfort. (author)

  2. First evidence of low energy enhancement in Ge isotopes

    Directory of Open Access Journals (Sweden)

    Renstrøm T.

    2015-01-01

    Full Text Available The γ-strength functions and level densities of 73,74Ge have been extracted from particle-γ coincidence data using the Oslo method. In addition the γ-strength function of 74Ge above the neutron separation threshold, Sn = 10.196 MeV has been extracted from photoneutron measurements. When combined, these two experiments give a γ-strength function covering the energy range of ∼1-13 MeV for 74Ge. This thorough investigation of 74Ge is a part of an international campaign to study the previously reported low energy enhancement in this mass region in the γ-strength function from ∼3MeV towards lower γ energies. The obtained data show that both 73,74Ge display an increase in strength at low γ energies.

  3. Luminescence model with quantum impact parameter for low energy ions

    CERN Document Server

    Cruz-Galindo, H S; Martínez-Davalos, A; Belmont-Moreno, E; Galindo, S

    2002-01-01

    We have modified an analytical model of induced light production by energetic ions interacting in scintillating materials. The original model is based on the distribution of energy deposited by secondary electrons produced along the ion's track. The range of scattered electrons, and thus the energy distribution, depends on a classical impact parameter between the electron and the ion's track. The only adjustable parameter of the model is the quenching density rho sub q. The modification here presented, consists in proposing a quantum impact parameter that leads to a better fit of the model to the experimental data at low incident ion energies. The light output response of CsI(Tl) detectors to low energy ions (<3 MeV/A) is fitted with the modified model and comparison is made to the original model.

  4. Photon energy-fluence correction factor in low energy brachytherapy

    International Nuclear Information System (INIS)

    Antunes, Paula C.G.; Yoriyaz, Hélio; Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo

    2017-01-01

    The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D tis ) and dose-to-water (D w ). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the 125 I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

  5. Photon energy-fluence correction factor in low energy brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Paula C.G.; Yoriyaz, Hélio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vijande, Javier; Giménez-Alventosa, Vicent; Ballester, Facundo, E-mail: pacrisguian@gmail.com [Department of Atomic, Molecular, and Nuclear Physics and Instituto de Física Corpuscular (UV-CSIC), University of Valencia (Spain)

    2017-07-01

    The AAPM TG-43 brachytherapy dosimetry formalism has become a standard for brachytherapy dosimetry worldwide; it implicitly assumes that charged-particle equilibrium (CPE) exists for the determination of absorbed dose to water at different locations. At the time of relating dose to tissue and dose to water, or vice versa, it is usually assumed that the photon fluence in water and in tissues are practically identical, so that the absorbed dose in the two media can be related by their ratio of mass energy-absorption coefficients. The purpose of this work is to study the influence of photon energy-fluence in different media and to evaluate a proposal for energy-fluence correction factors for the conversion between dose-to-tissue (D{sub tis}) and dose-to-water (D{sub w}). State-of-the art Monte Carlo (MC) calculations are used to score photon fluence differential in energy in water and in various human tissues (muscle, adipose and bone) in two different codes, MCNP and PENELOPE, which in all cases include a realistic modeling of the {sup 125}I low-energy brachytherapy seed in order to benchmark the formalism proposed. A correction is introduced that is based on the ratio of the water-to-tissue photon energy-fluences using the large-cavity theory. In this work, an efficient way to correlate absorbed dose to water and absorbed dose to tissue in brachytherapy calculations at clinically relevant distances for low-energy photon emitting seed is proposed. The energy-fluence based corrections given in this work are able to correlate absorbed dose to tissue and absorbed dose to water with an accuracy better than 0.5% in the most critical cases. (author)

  6. Low energy ion beam dynamics of NANOGAN ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sarvesh, E-mail: sarvesh@iuac.res.in; Mandal, A.

    2016-04-01

    A new low energy ion beam facility (LEIBF) has been developed for providing the mass analyzed highly charged intense ion beams of energy ranging from a few tens of keV to a few MeV for atomic, molecular and materials sciences research. The new facility consists of an all permanent magnet 10 GHz electron cyclotron resonance (ECR) ion source (NANOGAN) installed on a high voltage platform (400 kV) which provides large currents of multiply charged ion beams. Higher emittance at low energy of intense ion beam puts a tremendous challenge to the beam optical design of this facility. The beam line consists of mainly the electrostatic quadrupoles, an accelerating section, analyzing cum switching magnet and suitable beam diagnostics including vacuum components. The accelerated ion beam is analyzed for a particular mass to charge (m/q) ratio as well as guided to three different lines along 75°, 90° and 105° using a large acceptance analyzing cum switching magnet. The details of transverse beam optics to all the beam lines with TRANSPORT and GICOSY beam optics codes are being described. Field computation code, OPERA 3D has been utilized to design the magnets and electrostatic quadrupoles. A theoretical estimation of emittance for optimized geometry of ion source is given so as to form the basis of beam optics calculations. The method of quadrupole scan of the beam is used to characterize the emittance of the final beam on the target. The measured beam emittance increases with m/q ratios of various ion beams similar to the trend observed theoretically.

  7. Performance Evaluation of Bluetooth Low Energy: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Jacopo Tosi

    2017-12-01

    Full Text Available Small, compact and embedded sensors are a pervasive technology in everyday life for a wide number of applications (e.g., wearable devices, domotics, e-health systems, etc.. In this context, wireless transmission plays a key role, and among available solutions, Bluetooth Low Energy (BLE is gaining more and more popularity. BLE merges together good performance, low-energy consumption and widespread diffusion. The aim of this work is to review the main methodologies adopted to investigate BLE performance. The first part of this review is an in-depth description of the protocol, highlighting the main characteristics and implementation details. The second part reviews the state of the art on BLE characteristics and performance. In particular, we analyze throughput, maximum number of connectable sensors, power consumption, latency and maximum reachable range, with the aim to identify what are the current limits of BLE technology. The main results can be resumed as follows: throughput may theoretically reach the limit of ~230 kbps, but actual applications analyzed in this review show throughputs limited to ~100 kbps; the maximum reachable range is strictly dependent on the radio power, and it goes up to a few tens of meters; the maximum number of nodes in the network depends on connection parameters, on the network architecture and specific device characteristics, but it is usually lower than 10; power consumption and latency are largely modeled and analyzed and are strictly dependent on a huge number of parameters. Most of these characteristics are based on analytical models, but there is a need for rigorous experimental evaluations to understand the actual limits.

  8. Negotiating comfort in low energy housing: The politics of intermediation

    International Nuclear Information System (INIS)

    Grandclément, Catherine; Karvonen, Andrew; Guy, Simon

    2015-01-01

    Optimising the energy performance of buildings is technically and economically challenging but it also has significant social implications. Maintaining comfortable indoor conditions while reducing energy consumption involves careful design, construction, and management of the built environment and its inhabitants. In this paper, we present findings from the study of a new low energy building for older people in Grenoble, France where conflicts emerged over the simultaneous pursuit of energy efficiency and comfort. The findings contribute to the contemporary literature on the sociotechnical study of buildings and energy use by focusing on intermediation, those activities that associate a technology to end users. Intermediation activities take many forms, and in some cases, can result in the harmonisation or alignment of energy efficiency goals and comfort goals. In other cases, intermediation is unsuccessful, leading to the conventional dichotomy between optimising technical performance and meeting occupant preferences. By highlighting the multiple ways that comfort and energy efficiency is negotiated, we conclude that buildings are provisional achievements that are constantly being intermediated. This suggests that building energy efficiency policies and programmes need to provide opportunities for intermediaries to negotiate the desires and preferences of the multiple stakeholders that are implicated in low energy buildings. -- Highlights: •Energy efficiency and comfort are two possibly contradictory aims of buildings. •We study the pursuit of these aims at the occupation stage of a new building. •Aligning these aims involve negotiating them with occupants. •Intermediation processes are key to such negotiations. •Intermediation processes involve both actors and technical devices

  9. Performance of broiler chicken fed multicarbohydrases supplemented low energy diet

    Directory of Open Access Journals (Sweden)

    Kumar Govil

    2017-07-01

    Full Text Available Aim: Objective of this study was to investigate the effect of multicarbohydrases supplementation on performance of broilers fed low energy diet. Materials and Methods: A total of 75 days old chicks were selected and randomly divided into three treatments groups (T1, T2, and T3; each group contained 25 chicks distributed in five replicates of five chicks each. T1 group (positive control was offered control ration formulated as per Bureau of Indian Standards recommendations. In T2 group (negative control ration, metabolizable energy (ME was reduced by 100 kcal/kg diet. T3 group ration was same as that of T2 except that it was supplemented with multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton. Feed intake and body weight of all experimental birds were recorded weekly. Metabolic trial was conducted for 3 days at the end of experiment to know the retention of nutrients. Results: Significant improvement (p<0.01 was observed in total weight gain, feed conversion efficiency, and performance index in broilers under supplementary group T3 as compared to T1 and T2 groups. Retention of crude protein and ether extract was significantly increased (p<0.05 in T3 group supplemented with multicarbohydrases as compared to other groups. Retention of dry matter, crude fiber, and nitrogen-free extract was comparable in all the three groups. Significantly highest dressed weight, eviscerated weight, and drawn weight (% of live body weight were observed in multicarbohydrases supplemented T3 group, however it was comparable in T1 and T2 groups. Conclusion: It was concluded that the supplementation of multicarbohydrases (xylanase at 50 g/ton+mannanase at 50 g/ton+amylase at 40 g/ton in low energy diet improved overall performance of broilers.

  10. Variations of Low-energy Ion Distributions Measured in the Heliosheath

    International Nuclear Information System (INIS)

    Decker, R. B.; Roelof, E. C.; Hill, M. E.; Krimigis, S. M.

    2010-01-01

    This report is an update of low-energy ion intensities and angular distributions measured recently by the Low Energy Charged Particle instruments on the Voyager 1 and 2 spacecraft in the inner heliosheath.

  11. High beam current shut-off systems in the APS linac and low energy transfer line

    International Nuclear Information System (INIS)

    Wang, X.; Knott, M.; Lumpkin, A.

    1994-01-01

    Two independent high beam current shut-off current monitoring systems (BESOCM) have been installed in the APS linac and the low energy transport line to provide personnel safety protection in the event of acceleration of excessive beam currents. Beam current is monitored by a fast current transformer (FCT) and fully redundant supervisory circuits connected to the Access Control Interlock System (ACIS) for beam intensity related shutdowns of the linac. One FCT is located at the end of the positron linac and the other in the low energy transport line, which directs beam to the positron accumulator ring (PAR). To ensure a high degree of reliability, both systems employ a continuous self-checking function, which injects a test pulse to a single-turn test winding after each ''real'' beam pulse to verify that the system is fully functional. The system is designed to be fail-safe for all possible system faults, such as loss of power, open or shorted signal or test cables, loss of external trigger, malfunction of gated integrator, etc. The system has been successfully commissioned and is now a reliable part of the total ACIS

  12. Low energy X-ray radiation impact on coated Si constructions

    International Nuclear Information System (INIS)

    Adliene, D.; Cibulskaite, I.; Meskinis, S.

    2010-01-01

    Low energy X-ray radiation impact on the coated Si structures is discussed in this paper. Experimental sandwich structures consisting of amorphous hydrogenated a:C-H or SiO x -containing DLC films were synthesized on Si wafers using direct ion deposition method and exposed to low energy (medical diagnostic range) X-ray photons. Irradiation of samples was performed continuously or in sequences and protective characteristics of the irradiated DLC films were investigated. Experimental data were used as the input data for Monte Carlo modelling of X-ray scattering effects in the coated silicon constructions, which affect significantly the 'signal to noise ratio' in DLC-coated Si structures proposed for their application in medical radiation detectors. Modelling results obtained in the case of DLC coatings were compared to the results of calculations performed for other commonly used combinations coating-detector material. The evaluation method of coated structures for their possible application in medical radiation detector constructions has been proposed in this paper. It is based on the best achieved compatibility between the appropriate mechanical characteristics, coating's resistance against the radiation damage and the lowest estimated scattering to total dose ratio in the coated radiation sensitive volume.

  13. Probing quark mass effects in low-energy hadron physics

    International Nuclear Information System (INIS)

    Ditsche, Christoph

    2012-01-01

    Since quarks are confined inside hadrons, their properties as well as their contributions to hadronic observables can be assessed by indirect methods only. As the strength of the strong interaction increases with the spatial distance, the treatment of quantum chromodynamics at low energies in general requires non-perturbative methods like dispersion relations or lattice gauge theory. Based on the fact that the light quark masses are very small with respect to the typical hadronic mass scales for mesons and baryons, furthermore effective field theories can be constructed to describe low-energy properties and dynamics of hadrons perturbatively. The present work is concerned with two particularly interesting hadronic processes that are closely related to the light quark masses. Although distinct theoretical frameworks utilizing different calculational techniques are applied, in both cases the investigations at hand are prerequisites for high-precision analyses of the respective quark-mass effects. In the first part of this thesis, we investigate higher-order isospin-breaking effects in η→3π decays, namely η→π 0 π + π - and η→3π 0 , in chiral perturbation theory. By evaluating the second-order mixed strong and electromagnetic isospin-breaking corrections, we confirm the picture that the electromagnetic contributions are small. Therefore, η→3π is perfectly suited to extract isospin-breaking ratios of light quark masses via comparing theoretical predictions with experimental results. Since for an accurate determination a detailed description of the Dalitz plot distributions is necessary, we study the different effects of higher-order isospin breaking in η→3π on a more general basis. In particular, we investigate corrections to isospin relations between both decay channels at the level of Dalitz plot parameters, showing that the branching ratio of the two partial decay widths entails sizeable uncertainties. In the second part, we develop a dispersive

  14. Low-energy lepton violation from supersymmetric flipped SU(5)

    Energy Technology Data Exchange (ETDEWEB)

    Brahm, D.E.; Hall, L.J. (Physics Department, University of California, Berkeley, California 94720 (US) Theoretical Physics Group, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720)

    1989-10-01

    We construct a supersymmetric flipped SU(5){direct product}U(1) model which violates {ital R} parity and electron number at low energies, through a superpotential term (1/2{ital C}{sup {ital ijk}}L{sub i}L{sub j}E{sub k}{sup c}). Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the {ital C}{sup {ital ijk}} coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting {ital Z}{sup 0} decays are predicted: e.g., {ital Z}{sup 0}{r arrow}e{sup {minus}}{mu}{sup +}e{sup +}{mu}{sup {minus}} with invariant-mass peaks in the ({ital e},{mu}) channels.

  15. Dose controlled low energy electron irradiator for biomolecular films.

    Science.gov (United States)

    Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

    2016-03-01

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  16. Generalized hidden symmetry for low-energy hadron phsics

    International Nuclear Information System (INIS)

    Kaiser, N.; Meissner, U.G.

    1990-01-01

    We present a detailed study of an effective chiral meson lagrangian involving pseudoscalar, vector and axial-vector mesons. We employ the recently proposed technique to introduce vector and axial-vector mesons as composite gauge bosons of an extended hidden gauge symmetry of the non-linear σ-model. In particular, we write down the most general anomalous action (Wess-Zumino term) in accordance with low-energy theorems and chiral symmetry. The global flavor anomalies of QCD are given by the standard (5-dimensional) Wess-Zumino-Witten action of the pseudoscalar mesons, whereas all the processes violating natural parity for the vectors and axials are chirally (gauge) symmetric and therefore do not contribute to the Wess-Zumino anomaly equation. We find fourteen independent terms with a priori unknown (real) coefficients. We are able to fix some of these coefficients from anomalous hadronic and radiative vector/axial-vector meson decays. A comparison to the gauged Wess-Zumino action in the so-called massive Yang-Mills approach shows that both anomalous actions are indeed equivalent for a special choice of the unknown coefficients. We finally propose a realistic two-flavor chiral effective lagrangian incorporating pions, the vector mesons ρ and ω as well as the axial A 1 meson which should be used in skyrmion physics at energy scales up to about 1 GeV. (orig.)

  17. Charge-coupled device area detector for low energy electrons

    International Nuclear Information System (INIS)

    Horacek, Miroslav

    2003-01-01

    A fast position-sensitive detector was designed for the angle- and energy-selective detection of signal electrons in the scanning low energy electron microscope (SLEEM), based on a thinned back-side directly electron-bombarded charged-coupled device (CCD) sensor (EBCCD). The principle of the SLEEM operation and the motivation for the development of the detector are explained. The electronics of the detector is described as well as the methods used for the measurement of the electron-bombarded gain and of the dark signal. The EBCCD gain of 565 for electron energy 5 keV and dynamic range 59 dB for short integration time up to 10 ms at room temperature were obtained. The energy dependence of EBCCD gain and the detection efficiency are presented for electron energy between 2 and 5 keV, and the integration time dependence of the output signals under dark conditions is given for integration time from 1 to 500 ms

  18. Inelastic pion scattering by 13C at low energies

    International Nuclear Information System (INIS)

    Mitchell, J.H.

    1987-03-01

    Angular distributions for inelastically scattered pions were obtained for several states in 13 C at an incident energy of 65 MeV. The data include results from both π + and π - measurements. In addition, π - measurements were made at T/sub π/ = 50 MeV at one angle to give a two point fixed-q excitation function. The data are compared to theory and the data of others. As might be expected, medium corrections are shown to be considerably more important at low energies than at resonance. This is true for inelastic transitions of multipolarity 0,2 and 3. Parameters derived from an analysis of elastic pion scattering and SCX data also provide an adequate description of the inelastic transitions. The charge asymmetry in the cross sections for the 9/2 + state that was seen at resonance persists at these energies. This result is consistent with an impulse approximation treatment of the spin-flip amplitude. This is true even though the incoming energy of the pions is far below the range where the validity of an impulse treatment is expected. 65 refs., 45 figs

  19. Fundamentals of low-energy neutral atom imaging

    International Nuclear Information System (INIS)

    McComas, D.J.; Funsten, H.O.; Gosling, J.T.; Moore, K.R.; Scime, E.E.; Thomsen, M.F.

    1994-01-01

    Imaging of the space plasma environment via low-energy neutral atoms (LENAs) promises to revolutionize the way in which large-scale space plasma phenomena are viewed and understood. LENAs are produced by charge exchange between plasma ions (less than tens of kilo-electron-volts) and cold geocoronal neutrals; these LENAs radiate outward in all directions from their points of origin. Previously developed methods for imaging higher energy neutrals are not suitable for observing the majority of the terrestrial magnetosphere, which is comprised primarily of lower energy plasma populations. This paper briefly describes both the direct and indirect techniques that have been suggested for imaging LENAs to date. The authors then examine in more detail the most advanced of these techniques appropriate for magnetospheric imaging, indirect detection based on ionization of LENAs as they transit ultra thin foils. Such a LENA imager consists of four basic components: (1) a biased collimator to remove the ambient charged particles and set the azimuthal field of view; (2) an ultra thin foil, which ionizes a portion of the incident LENAs; (3) an electrostatic analyzer to reject UV light and set the energy passband; and (4) a coincidence position detector to measure converted LENAs while rejecting noise and penetrating radiation

  20. Comparative study of low-energy neutral atom imaging techniques

    International Nuclear Information System (INIS)

    Funsten, H.O.; McComas, D.J.; Scime, E.E.

    1994-01-01

    Low-energy neutral atom (LENA) imaging promise to be a revolutionary tool for global imaging of space plasmas. The technical challenges of LENA detection include separating them from the intense ambient UV without losing information about their incident trajectories, quantifying their trajectories, and obtaining high-sensitivity measurements. Two techniques that have been proposed for this purpose are based on fundamentally different atomic interaction mechanisms between LENAs and a solid; LENA transmission through an ultra thin foil and LENA reflection from a solid surface. Both of these methods provide LENA ionization (for subsequent removal from the UV by electrostatic deflection) and secondary electron emission (for time-of-flight start pulse generation and/or coincidence). They present a comparative study of the transmission and reflection techniques based on differences in atomic interactions with solids and surfaces. Transmission methods are shown to be superior for secondary electron emission rather than reflection methods. Furthermore, transmission methods are shown to be a sufficient for LENA imaging at LENA energies of approximately 1 keV to greater than 30 keV. A hybrid instrument using reflection from a low work function surface for LENA ionization and transmission for secondary electron emission is optimal for imaging of LENAs with energies less than approximately 1 keV

  1. Terrestrial magnetospheric imaging: Numerical modeling of low energy neutral atoms

    International Nuclear Information System (INIS)

    Moore, K.R.; Funsten, H.O.; McComas, D.J.; Scime, E.E.; Thomsen, M.F.

    1993-01-01

    Imaging of the terrestrial magnetosphere can be performed by detection of low energy neutral atoms (LENAs) that are produced by charge exchange between magnetospheric plasma ions and cold neutral atoms of the Earth's geocorona. As a result of recent instrumentation advances it is now feasible to make energy-resolved measurements of LENAs from less than I key to greater than 30 key. To model expected LENA fluxes at a spacecraft, we initially used a simplistic, spherically symmetric magnetospheric plasma model. 6 We now present improved calculations of both hydrogen and oxygen line-of-sight LENA fluxes expected on orbit for various plasma regimes as predicted by the Rice University Magnetospheric Specification Model. We also estimate expected image count rates based on realistic instrument geometric factors, energy passbands, and image accumulation intervals. The results indicate that presently proposed LENA instruments are capable of imaging of storm time ring current and potentially even quiet time ring current fluxes, and that phenomena such as ion injections from the tail and subsequent drifts toward the dayside magnetopause may also be deduced

  2. Low-energy neutral atom emission from the Earth's magnetosphere

    International Nuclear Information System (INIS)

    Moore, K.R.; Scime, E.E.; Funsten, H.O.; McComas, D.J.; Thomsen, M.F.

    1994-01-01

    Imaging of the terrestrial magnetosphere is possible through the detection of low-energy neutral atoms (LENAs) produced by charge exchange between magnetospheric plasma ions and neutral atoms of the Earth's geocorona. The authors present calculations of both hydrogen and oxygen line-of-sight LENA fluxes expected on orbit for various plasma regimes as predicted by the Rice University Magnetospheric Specification Model. To decrease the required computation time, they are in the process of adapting their code for massively parallel computers. The speed gains achieved from parallel algorithms are substantial, and they present results from computational runs on the Connection Machine CM-2 data parallel supercomputer. They also estimate expected image count rates and image quality based on realistic instrument geometric factors, energy passbands, neutral atom scattering in the instrument, and image accumulation intervals. The results indicate that LENA imaging instruments will need a geometric factor (G) on the order of 0.1 cm 2 sr eV/eV to be capable of imaging storm time ring currents, and a G of 1.0 cm 2 sr eV/eV in order to image the quiet time ring current fluxes, ion injections from the tail, and subsequent ion drifts toward the dayside magnetopause

  3. AES based secure low energy adaptive clustering hierarchy for WSNs

    Science.gov (United States)

    Kishore, K. R.; Sarma, N. V. S. N.

    2013-01-01

    Wireless sensor networks (WSNs) provide a low cost solution in diversified application areas. The wireless sensor nodes are inexpensive tiny devices with limited storage, computational capability and power. They are being deployed in large scale in both military and civilian applications. Security of the data is one of the key concerns where large numbers of nodes are deployed. Here, an energy-efficient secure routing protocol, secure-LEACH (Low Energy Adaptive Clustering Hierarchy) for WSNs based on the Advanced Encryption Standard (AES) is being proposed. This crypto system is a session based one and a new session key is assigned for each new session. The network (WSN) is divided into number of groups or clusters and a cluster head (CH) is selected among the member nodes of each cluster. The measured data from the nodes is aggregated by the respective CH's and then each CH relays this data to another CH towards the gateway node in the WSN which in turn sends the same to the Base station (BS). In order to maintain confidentiality of data while being transmitted, it is necessary to encrypt the data before sending at every hop, from a node to the CH and from the CH to another CH or to the gateway node.

  4. Dynamics of anion-molecule reactions at low energy

    International Nuclear Information System (INIS)

    Mikosch, J.

    2007-11-01

    Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S N 2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S N 2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S N 2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S N 2 mechanism involving CH 3 -rotation. (orig.)

  5. Review of lattice results concerning low-energy particle physics

    International Nuclear Information System (INIS)

    Aoki, S.; Aoki, Y.; Brookhaven National Laboratory, Upton, NY; Becirevic, D.

    2016-07-01

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f_+(0), arising in the semileptonic K→π transition at zero momentum transfer, as well as the decay constant ratio f_K/f_π and its consequences for the CKM matrix elements V_u_s and V_u_d. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)_L x SU(2)_R and SU(3)_L x SU(3)_R Chiral Perturbation Theory. We review the determination of the B_K parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m_c and m_b (also new compared to the previous review), as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α_s.

  6. Transport and matching of low energy space charge dominated beams

    International Nuclear Information System (INIS)

    Pandit, V.S.

    2013-01-01

    The transport and matching of low energy high intensity beams from the ion source to the subsequent accelerating structure are of considerable interest in recent years for variety of applications such as Accelerator driven system (ADSS), transmutation of nuclear waste, spallation neutron sources etc. It is essential to perform detailed simulations with experimentation to predict the beam evolution in the presence of nonlinear self as well as external fields before the design of the next accelerating structure is finalized. In order to study and settle various physics and technical issues related with transport of space charge dominated beams we have developed a 2.45 GHz microwave ion source at VECC which is now delivering more than 10 mA proton beam current at 80 keV. We have successfully transported well collimated 8 mA proton beam through the solenoid based 3 meter long transport line and studied various beam properties. We have also studied the transport of beam through spiral inflector at low beam current ∼ 1mA. In this article we will discuss the beam transport issues and describe a technique for simulation of beam envelopes in presence of linear space charge effects. We use canonical description of the motion of a single particle and then obtain first order differential equations for evolution of the moments of beam ensemble by assuming uniform distribution of the beam. We will also discuss the methodology used in the simulations to understand the observed beam behaviour during transport. (author)

  7. Low energy microcolumn for large field view inspection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Chul [Department of Optometry, Eulji University, 212 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 461-713 (Korea, Republic of); Ahn, Seung-Joon; Oh, Tae-Sik; Kim, Dae-Wook [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Kim, Ho-Seob, E-mail: hskim3@sunmoon.ac.kr [Department of Nanoscience, Sun Moon University 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Jang, Won Kweon [Division of Electronic, Computer and Communication Engineering, Hanseo University 360 DaeKook-ri, Haemi-myun, Seosan-si, Chungnam 356-706 (Korea, Republic of)

    2011-12-15

    Since the development of microcolumn system, it attracted much attention because multiple microcolumns can be assembled into arrayed form, which is expected to generate multiple electron beams and overcome the disadvantage of electron beam inspection equipments, low throughput . However, it is not easy to apply a microcolumn to the practical inspection or testing equipment since its scanning area is too small. Even if the arrayed operation using multiple microcolumns can overcome this limit, it requires complicated supporting systems and related technologies to operate a number of microcolumns simultaneously. Therefore, we tried to modify microcolumn design itself so that it can have a large field of view. In this work, two kinds of modified columns will be suggested and the preliminary results showing their performance of scanning large area will be discussed. -- Highlights: Black-Right-Pointing-Pointer Two types of microcolumn designs to achieve a large field of view are fabricated. Black-Right-Pointing-Pointer Field of view of a microcolumn increases linearly with the working distance. Black-Right-Pointing-Pointer New designed microcolumns can be developed as a low energy column system for large view inspections.

  8. Advanced photon source low-energy undulator test line

    International Nuclear Information System (INIS)

    Milton, S.V.

    1997-01-01

    The injector system of the Advanced Photon Source (APS) consists of a linac capable of producing 450-MeV positrons or > 650-MeV electrons, a positron accumulator ring (PAR), and a booster synchrotron designed to accelerate particles to 7 GeV. There are long periods of time when these machines are not required for filling the main storage ring and instead can be used for synchrotron radiation research. We describe here an extension of the linac beam transport called the Low-Energy Undulator Test Line (LEUTL). The LEUTL will have a twofold purpose. The first is to fully characterize innovative, future generation undulators, some of which may prove difficult or impossible to measure by traditional techniques. These might include small-gap and superconducting undulators, very long undulators, undulators with designed-in internal focusing, and helical undulators. This technique also holds the promise of extending the magnetic measurement sensitivity beyond that presently attainable. This line will provide the capability to directly test undulators before their possible insertion into operating storage rings. A second use for the test line will be to investigate the generation of coherent radiation at wavelengths down to a few tens of nanometers

  9. Wettability Modification of Nanomaterials by Low-Energy Electron Flux

    Directory of Open Access Journals (Sweden)

    Torchinsky I

    2009-01-01

    Full Text Available Abstract Controllable modification of surface free energy and related properties (wettability, hygroscopicity, agglomeration, etc. of powders allows both understanding of fine physical mechanism acting on nanoparticle surfaces and improvement of their key characteristics in a number of nanotechnology applications. In this work, we report on the method we developed for electron-induced surface energy and modification of basic, related properties of powders of quite different physical origins such as diamond and ZnO. The applied technique has afforded gradual tuning of the surface free energy, resulting in a wide range of wettability modulation. In ZnO nanomaterial, the wettability has been strongly modified, while for the diamond particles identical electron treatment leads to a weak variation of the same property. Detailed investigation into electron-modified wettability properties has been performed by the use of capillary rise method using a few probing liquids. Basic thermodynamic approaches have been applied to calculations of components of solid–liquid interaction energy. We show that defect-free, low-energy electron treatment technique strongly varies elementary interface interactions and may be used for the development of new technology in the field of nanomaterials.

  10. Sgoldstino-less inflation and low energy SUSY breaking

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes, Université Libre de Bruxelles, CP231, B-1050 Brussels (Belgium); Coone, Dries; Mariotti, Alberto [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Heurtier, Lucien, E-mail: rargurio@ulb.ac.be, E-mail: a.a.coone@rug.nl, E-mail: lucien.heurtier@ulb.ac.be, E-mail: alberto.mariotti@vub.ac.be [Service de Physique Théorique, Université Libre de Bruxelles, CP225, B-1050 Brussels (Belgium)

    2017-07-01

    We assess the range of validity of sgoldstino-less inflation in a scenario of low energy supersymmetry breaking. We first analyze the consistency conditions that an effective theory of the inflaton and goldstino superfields should satisfy in order to be faithfully described by a sgoldstino-less model. Enlarging the scope of previous studies, we investigate the case where the effective field theory cut-off, and hence also the sgoldstino mass, are inflaton-dependent. We then introduce a UV complete model where one can realize successfully sgoldstino-less inflation and gauge mediation of supersymmetry breaking, combining the α-attractor mechanism and a weakly coupled model of spontaneous breaking of supersymmetry. In this class of models we find that, given current limits on superpartner masses, the gravitino mass has a lower bound of the order of the MeV, i.e. we cannot reach very low supersymmetry breaking scales. On the plus side, we recognize that in this framework, one can derive the complete superpartner spectrum as well as compute inflation observables, the reheating temperature, and address the gravitino overabundance problem. We then show that further constraints come from collider results and inflation observables. Their non trivial interplay seems a staple feature of phenomenological studies of supersymmetric inflationary models.

  11. Fusion reaction using low energy neutron-excess nucleus beam

    International Nuclear Information System (INIS)

    Fukuda, Tomokazu

    1994-01-01

    The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

  12. Emittance scanner for intense low-energy ion beams

    International Nuclear Information System (INIS)

    Allison, P.W.; Sherman, J.D.; Holtkamp, D.B.

    1983-01-01

    An emittance scanner has been developed for use with low-energy H - ion beams to satisfy the following requirements: (1) angular resolution of +-1/2 mrad, (2) small errors from beam space charge, and (3) compact and simple design. The scanner consists of a 10-cm-long analyzer containing two slits and a pair of electric deflection plates driven by a +-500-V linear ramp generator. As the analyzer is mechanically driven across the beam, the front slit passes a thin ribbon of beam through the plates. The ion transit time is short compared with the ramp speed; therefore, the initial angle of the ions that pass through the rear slit is proportional to the instantaneous ramp voltage. The current through the rear slit then is proportional to the phase-space density d 2 i/dxdx'. The data are computer-analyzed to give, for example, rms emittance and phase-space density contours. Comparison of measured data with those calculated from a prepared (collimated) phase space is in good agreement

  13. Low-energy radioactive ion beam production of 22Mg

    International Nuclear Information System (INIS)

    Duy, N.N.; Kubono, S.; Yamaguchi, H.; Kahl, D.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Kwon, Y.K.; Khiem, L.H.; Kim, Y.H.; Song, J.S.; Hu, J.; Ayyad, Y.

    2013-01-01

    The 22 Mg nucleus plays an important role in nuclear astrophysics, specially in the 22 Mg(α,p) 25 Al and proton capture 22 Mg(p,γ) 23 Al reactions. It is believed that 22 Mg is a waiting point in the αp-process of nucleosynthesis in novae. We proposed a direct measurement of the 22 Mg+α resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22 Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22 Mg beam used for the direct measurement of the scattering reaction 22 Mg(α,α) 22 Mg, and the stellar reaction 22 Mg(α,p) 25 Al in the energy region concerning an astrophysical temperature of T 9 =1–3 GK

  14. District Heating in Areas with Low Energy Houses

    DEFF Research Database (Denmark)

    Tol, Hakan Ibrahim

    -energy houses involved, together with the idea of utilizing booster pumps in the district heating network and (ii) use of network layouts of either a branched (tree-like) or a looped type. The methods developed were applied in a case study, the data of which was provided by the municipality of Roskilde...... in Denmark. The second case study was aimed at solving another regional energy planning scheme, one concerned with already existing houses, the heat requirements of which were currently being met by use of a natural gas grid or a conventional high-temperature district heating network. The idea considered......This PhD thesis presents a summary of a three-year PhD project involving three case studies, each pertaining to a typical regional Danish energy planning scheme with regard to the extensive use of low-energy district heating systems, operating at temperatures as low as 55°C for supply and 25°C...

  15. Theory of the low-energy pion-nucleon interaction

    International Nuclear Information System (INIS)

    Banerjee, M.K.; Cammarata, J.B.

    1978-01-01

    A once-subtracted form of the Low equation for the pion-nucleon scattering amplitude is derived, with partial conservation of axial-vector current used to define the amplitude when one pion is off the mass shell. The static approximation is not made and both the seagull terms and the antinucleon contribution (z graphs) are retained. The theory is applied to calculate the S-wave amplitudes in the elastic scattering region. Good agreement is found with the phase shift fits to the data when we use vertical-barg/sub π/(4M 2 ) vertical-bar = 11.69 and 25.5 MeV for the πN sigma commutator. The implications of this work for the analysis of low-energy elastic scattering of pions form nuclei are discussed. In particular, we point out how this work establishes the presence of a Laplacian term in the pion-nucleus optical potential with a magnitude that is fixed from the value of the sigma commutator

  16. Individual Low-Energy Toroidal Dipole State in Mg 24

    Science.gov (United States)

    Nesterenko, V. O.; Repko, A.; Kvasil, J.; Reinhard, P.-G.

    2018-05-01

    The low-energy dipole excitations in Mg 24 are investigated within the Skyrme quasiparticle random phase approximation for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest IπK =1-1 excitation (E =7.92 MeV ) in Mg 24 is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of the well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an individual TS which can be much more easily discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in Mg 24 . The result persists for different Skyrme parametrizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of Mg 24 . Similar TSs could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.

  17. Interlaboratory comparison of low energies anthropo-radiometers

    International Nuclear Information System (INIS)

    Didier, F.; Berard, Ph.; Dubiau, C.; Soulie, R.

    1999-01-01

    The radio-toxicology of actinides (U, Pu, Am) has for aim to verify the norms respect by proceeding to doses evaluations following an internal irradiation. The in vivo measure, called also pulmonary anthropo-radiometry consists in estimating the quantity of radionuclides present in lungs by the direct measurement of their low energies X and gamma rays. This technique is particularly used at the Laboratories of Medical Biology Analysis. It has the great advantage to give the totality of activity present at a given time and kept in lungs. But the low activities to measure and the strong absorption of rays in these tissues lead to a lack of sensitivity of measurement systems usually used and to a difficulty in calibrating these installations. These determinations need performing methods to detect and quantify some quantities of actinides in human body. Nine laboratories have taken part in intercomparison, the results have allowed to collect numerous and very useful information, the following objective is to realize a French standardization of practices in the anthropo-radiometry measurement. (N.C.)

  18. Channeling effect for low energy ion implantation in Si

    International Nuclear Information System (INIS)

    Cho, K.; Allen, W.R.; Finstad, T.G.; Chu, W.K.; Liu, J.; Wortman, J.J.

    1985-01-01

    Ion implantation is one of the most important processes in semiconductor device fabrication. Due to the crystalline nature of Si, channeling of implanted ions occurs during this process. Modern devices become smaller and shallower and therefore require ion implantation at lower energies. The effect of channeling on ion implantation becomes a significant problem for low energy ion implantation. The critical angle for axial and planar channeling increases with decreasing energy. This corresponds to an increased probability for channeling with lowering of ion energy. The industry approach to avoid the channeling problem is to employ a tilt angle of 7 0 between the ion implantation direction and the surface normal. We approach the problem by mapping major crystalline axes and planes near the [100] surface normal. Our analysis indicates that a 7 0 tilt is not an optimum selection in channeling reduction. Tilt angles in the range 5 0 to 6 0 combined with 7 0 +- 0.5 0 rotation from the (100) plane are better selections for the reduction of the channeling effect. The range of suitable angles is a function of the implantation energy. Implantations of boron along well specified crystallographic directions have been carried out by careful alignment and the resulting boron profiles measured by SIMS. (orig.)

  19. Automation of variable low-energy positron beam experiments

    CERN Document Server

    Jayapandian, J; Amarendra, G; Venugopal-Rao, G; Purniah, B; Viswanathan, B

    2000-01-01

    By exploiting the special BIOS interrupt (INT 1CH) of PC in conjunction with a compatible high-voltage controller card and menu-driven control program, we report here the automation of variable low-energy positron beam experiments. The beam experiment consists of monitoring the Doppler broadening lineshape parameters corresponding to the annihilation 511 keV gamma-ray at various positron beam implantation energies. The variation and monitoring of the sample high voltage, which determines positron beam energy, is carried out using a controller add-on card coupled to a 0-30 kV high-voltage unit. The design features of this controller card are discussed. This controller card is housed in a PC, which also houses a multichannel analyser (MCA) card. The MCA stores the Doppler energy spectrum of the annihilation gamma-ray. The interactive control program, written in Turbo C, carries out the assigned tasks. The design features of the automation and results are presented.

  20. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report by Lawrence Berkeley National Laboratory identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most U.S. locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  1. Addressing Kitchen Contaminants for Healthy, Low-Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Stratton, J. Chris; Singer, Brett C.

    2014-01-01

    Cooking and cooking burners emit pollutants that can adversely affect indoor air quality in residences and significantly impact occupant health. Effective kitchen exhaust ventilation can reduce exposure to cooking-related air pollutants as an enabling step to healthier, low-energy homes. This report identifies barriers to the widespread adoption of kitchen exhaust ventilation technologies and practice and proposes a suite of strategies to overcome these barriers. The recommendations have been vetted by a group of industry, regulatory, health, and research experts and stakeholders who convened for two web-based meetings and provided input and feedback to early drafts of this document. The most fundamental barriers are (1) the common misconception, based on a sensory perception of risk, that kitchen exhaust when cooking is unnecessary and (2) the lack of a code requirement for kitchen ventilation in most US locations. Highest priority objectives include the following: (1) Raise awareness among the public and the building industry of the need to install and routinely use kitchen ventilation; (2) Incorporate kitchen exhaust ventilation as a requirement of building codes and improve the mechanisms for code enforcement; (3) Provide best practice product and use-behavior guidance to ventilation equipment purchasers and installers, and; (4) Develop test methods and performance targets to advance development of high performance products. A specific, urgent need is the development of an over-the-range microwave that meets the airflow and sound requirements of ASHRAE Standard 62.2.

  2. Progress update on the low-energy demonstration accelerator (LEDA)

    International Nuclear Information System (INIS)

    Schneider, J.D.; Chan, K.C.D.

    1997-01-01

    As part of the linac design for the accelerator production of tritium (APT) project, the authors are assembling the first approximately 20 MeV portion of this cw proton accelerator. Primary objective of this low-energy demonstration accelerator (LEDA) is to verify the design codes, gain fabrication knowledge, understand LEDA's beam operation, and be able to better predict costs and operational availability for the full 1,700 MeV APT accelerator. This paper provides an updated report on this past year's progress that includes beam tests of the 75 keV injector, fabrication of the 6.7 MeV radio-frequency quadrupole (RFQ), preparation of the facility, procurement and assembly of the rf system, and detailed design and documentation of many pieces of support equipment. First tests with the 6.7 MeV, 100 mA, cw beam from the RFQ are scheduled for late 1998. References are given to many detailed papers on LEDA at this conference

  3. Low energy booster radio frequency cavity structural analysis

    International Nuclear Information System (INIS)

    Jones, K.

    1994-01-01

    The structural design of the Superconducting Super Collider Low Energy Booster (LEB) Radio Frequency (RF) Cavity is very unique. The cavity is made of three different materials which all contribute to its structural strength while at the same time providing a good medium for magnetic properties. Its outer conductor is made of thin walled stainless steel which is later copper plated to reduce the electrical losses. Its tuner housing is made of a fiber reinforced composite laminate, similar to G10, glued to stainless steel plating. The stainless steel of the tuner is slotted to significantly diminish the magnetically-induced eddy currents. The composite laminate is bonded to the stainless steel to restore the structural strength that was lost in slotting. The composite laminate is also a barrier against leakage of the pressurized internal ferrite coolant fluid. The cavity's inner conductor, made of copper and stainless steel, is subjected to high heat loads and must be liquid cooled. The requirements of the Cavity are very stringent and driven primarily by deflection, natural frequency and temperature. Therefore, very intricate finite element analysis was used to complement conventional hand analysis in the design of the cavity. Structural testing of the assembled prototype cavity is planned to demonstrate the compliance of the cavity design to all of its requirements

  4. Low energy booster radio frequency cavity structural analysis

    International Nuclear Information System (INIS)

    Jones, K.

    1993-04-01

    The structural design of the Superconducting Super Collider Low Energy Booster (LEB) Radio Frequency (RF) Cavity is very unique. The cavity is made of three different materials which all contribute to its structural strength while at the same time providing a good medium for magnetic properties. Its outer conductor is made of thin walled stainless steel which is later copper plated to reduce the electrical losses. Its tuner housing is made of a fiber reinforced composite laminate, similar to G10, glued to stainless steel plating. The stainless steel of the tuner is slotted to significantly diminish the magnetically-induced eddy currents. The composite laminate is bonded to the stainless steel to restore the structural strength that was lost in slotting. The composite laminate is also a barrier against leakage of the pressurized internal ferrite coolant fluid. The cavity's inner conductor, made of copper and stainless steel, is subjected to high heat loads and must be liquid cooled. The requirements of the Cavity are very stringent and driven primarily by deflection, natural frequency and temperature. Therefore, very intricate finite element analysis was used to complement conventional hand analysis in the design of the cavity. Structural testing of the assembled prototype cavity is planned to demonstrate the compliance of the cavity design to all of its requirements

  5. Low energy electron microscopy imaging using Medipix2 detector

    International Nuclear Information System (INIS)

    Sikharulidze, I.; Gastel, R. van; Schramm, S.; Abrahams, J.P.; Poelsema, B.; Tromp, R.M.; Molen, S.J. van der

    2011-01-01

    Low Energy Electron Microscopy (LEEM) and Photo-Emission Electron Microscopy (PEEM) predominantly use a combination of microchannel plate (MCP), phosphor screen and optical camera to record images formed by 10-20 keV electrons. We have tested the performance of a LEEM/PEEM instrument with a Medipix2 hybrid pixel detector using an Ir(1 1 1) sample with graphene flakes grown on its surface. We find that Medipix2 offers a number of advantages over the MCP. The adjustable threshold settings allow Medipix2 to operate as a noiseless detector, offering an improved signal-to-noise ratio for the same amount of signal compared to the MCP. At the same magnification Medipix2 images exhibit superior resolution and can handle significantly higher electron current densities than an MCP, offering the prospect of substantially higher frame rates in LEEM imaging. These factors make Medipix2 an excellent candidate to become the detector of choice for LEEM/PEEM applications.

  6. Low energy electron microscopy imaging using Medipix2 detector

    Energy Technology Data Exchange (ETDEWEB)

    Sikharulidze, I., E-mail: irakli@chem.leidenuniv.nl [Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300RA Leiden (Netherlands); Gastel, R. van [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands); Schramm, S. [Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300RA Leiden (Netherlands); Abrahams, J.P. [Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300RA Leiden (Netherlands); Poelsema, B. [MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands); Tromp, R.M. [Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300RA Leiden (Netherlands); IBM Research Division, T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598 (United States); Molen, S.J. van der [Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300RA Leiden (Netherlands)

    2011-05-15

    Low Energy Electron Microscopy (LEEM) and Photo-Emission Electron Microscopy (PEEM) predominantly use a combination of microchannel plate (MCP), phosphor screen and optical camera to record images formed by 10-20 keV electrons. We have tested the performance of a LEEM/PEEM instrument with a Medipix2 hybrid pixel detector using an Ir(1 1 1) sample with graphene flakes grown on its surface. We find that Medipix2 offers a number of advantages over the MCP. The adjustable threshold settings allow Medipix2 to operate as a noiseless detector, offering an improved signal-to-noise ratio for the same amount of signal compared to the MCP. At the same magnification Medipix2 images exhibit superior resolution and can handle significantly higher electron current densities than an MCP, offering the prospect of substantially higher frame rates in LEEM imaging. These factors make Medipix2 an excellent candidate to become the detector of choice for LEEM/PEEM applications.

  7. Low-energy positron interactions with atoms and molecules

    International Nuclear Information System (INIS)

    Surko, C M; Gribakin, G F; Buckman, S J

    2005-01-01

    This paper is a review of low-energy positron interactions with atoms and molecules. Processes of interest include elastic scattering, electronic and vibrational excitation, ionization, positronium formation and annihilation. An overview is presented of the currently available theoretical and experimental techniques to study these phenomena, including the use of trap-based positron beam sources to study collision processes with improved energy resolution. State-resolved measurements of electronic and vibrational excitation cross sections and measurement of annihilation rates in atoms and molecules as a function of incident positron energy are discussed. Where data are available, comparisons are made with analogous electron scattering cross sections. Resonance phenomena, common in electron scattering, appear to be less common in positron scattering. Possible exceptions include the sharp onsets of positron-impact electronic and vibrational excitation of selected molecules. Recent energy-resolved studies of positron annihilation in hydrocarbons containing more than a few carbon atoms provide direct evidence that vibrational Feshbach resonances underpin the anomalously large annihilation rates observed for many polyatomic species. We discuss open questions regarding this process in larger molecules, as well as positron annihilation in smaller molecules where the theoretical picture is less clear. (topical review)

  8. Strong interactions and electromagnetism in low-energy hadron physics

    International Nuclear Information System (INIS)

    Kubis, B.

    2002-10-01

    In the present work, we study various aspects of the entanglement of the strong and electromagnetic interactions as it is manifest in low-energy hadron physics. In the framework of chiral perturbation theory, two aspects are investigated: the test of the structure of baryons as probed by external electromagnetic currents, and the modification of reactions mediated by the strong interactions in the presence of internal (virtual) photons. In the first part of this work, we study the electromagnetic form factors of nucleons and the ground state baryon octet, as well as strangeness form factors of the nucleon. Emphasis is put on the comparison of a new relativistic scheme for the calculation of loop diagrams to the heavy-baryon formalism, and on the convergence of higher-order corrections in both schemes. The new scheme is shown to yield both a phenomenologically more successful description of the data and better convergence behaviour. In the second part, we study isospin violation in pion-kaon scattering as mediated by virtual photon effects and the light quark mass difference. This investigation is of particular importance for the extraction of scattering lengths from measurements of lifetime and energy levels in pion-kaon atoms. The isospin breaking corrections are shown to be small and sufficiently well under control. (orig.)

  9. Stopping powers of solids for low-energy protons

    International Nuclear Information System (INIS)

    Ashley, J.C.; Ritchie, R.H.

    1984-01-01

    Electron gas models are useful approximations for describing the valence electron response of a solid to the passage of a charged particle. A simple free-electron gas model was used by Fermi and Teller to estimate the time required for a mesotron to be stopped in various solids. More recent work has employed the Lindhard dielectric response function, or approximations thereto, for calculations of the valence electron contributions to energy loss per unit pathlength for protons. Such calculations have generally shown rather poor agreement with experimental data for low-energy protons (velocity small compared to the Fermi velocity, v<< v/sub F/). The purpose of this paper is to draw attention to a recent calculation of the stopping power for slow protons using a density-functional formalism. These new results have been shown to give good agreement with experimental data and thus should provide valuable theoretical guidance in estimating stopping powers of solids for which no experimental data are available

  10. Low-energy antikaon nucleon and nucleus interaction studies

    Science.gov (United States)

    Marton, Johann; Leannis Collaboration

    2011-04-01

    The antikaon (K-) interaction on nucleons and nuclei at low energy is neither simple nor well understood. Kaonic hydrogen is a very interesting case where the strong interaction of K- with the proton leads to an energy shift and a broadening of the 1s ground state. These two observables can be precisely studied with x-ray spectroscopy. The behavior at threshold is influenced strongly by the elusive Lambda(1405) resonance. In Europe the DAFNE electron-positron collider at Laboratori Nazionali di Frascati (LNF) provides an unique source of monoenergetic kaons emitted in the Phi meson decay. Recently the experiment SIDDHARTA on kaonic hydrogen and helium isotopes was successfully performed at LNF. A European network LEANNIS with an outreach to J-PARC in Japan was set up which is promoting the research on the antikaon interactions with nucleons and nuclei. This talk will give an overview of LEANNIS research tasks, the present status and an outlook to future perspectives. Financial support by the EU project HadronPhysics2 is gratefully acknowledged.

  11. Argon defect complexes in low energy Ar irradiated molybdenum

    International Nuclear Information System (INIS)

    Veen, A. van; Buters, W.T.M.; Kolk, G.J. van der; Caspers, L.M.; Armstrong, T.R.

    1982-01-01

    Thermal desorption spectrometry has been used to study the defects created in Mo irradiated along the direction with Ar ions ranging in energy from 0.1 to 2 keV. In addition to monitoring the release of the implanted Ar, additional information has been obtained by decoration of the defects with low energy helium and subsequent monitoring of the helium release. The studies show evidence that the Ar can be trapped in both substitutional sites and in a configuration in which the Ar is associated with vacancies (ArVsub(n), n >= 2). Most of the Ar implanted at high energy is released at approx. equal to 1500 K by thermal vacancy assisted diffusion. Argon trapped closer to the surface is released at lower temperatures via at least three different surface related release mechanisms. Additional results are presented on the interaction of self interstitial atoms (introduced by 100 eV Xe bombardment) with the Ar defects. Substitutional Ar is found to convert to interstitial Ar which seems to be mobile at room temperature. The Ar-vacancy complexes are found to be reduced to substitutional Ar. The results of atomistic calculations of the release mechanisms will also be presented. (orig.)

  12. Low Energy Trauma in Older Persons: Where to Next?

    Science.gov (United States)

    Chehade, Mellick; Gill, Tiffany K; Visvanathan, Renuka

    2015-01-01

    The global population is increasing rapidly with older persons accounting for the greatest proportion. Associated with this rise is an increased rate of injury, including polytrauma, for which low energy falls has become the main cause. The resultant growing impact on trauma resources represents a major burden to the health system. Frailty, with its related issues of cognitive dysfunction and sarcopenia, is emerging as the unifying concept that relates both to the initial event and subsequent outcomes. Strategies to better assess and manage frailty are key to both preventing injury and improving trauma outcomes in the older population and research that links measures of frailty to trauma outcomes will be critical to informing future directions and health policy. The introduction of "Geriatric Emergency Departments" and the development of "Fracture Units" for frail older people will facilitate increased involvement of Geriatricians in trauma care and aid in the education of other health disciplines in the core principles of geriatric assessment and management. Collectively these should lead to improved care and outcomes for both survivors and those requiring end of life decisions and palliation.

  13. CO ionization and fragmentation by low-energy positrons.

    Science.gov (United States)

    Schrader, D. M.; Moxom, J.

    2000-06-01

    Using the positron beam associated with the electron LINAC ORELA at Oak Ridge National Laboratory, ion yields from carbon monoxide colliding with positrons of low energy are observed as functions of positron beam energy from threshold to 100 eV. Observed appearence potentials are compared with those for electron bombardment, and are interpreted with the aid of potential energy curves for CO, CO^+, and CO^2+. The latter are calculated in the present work at the FORS/MCSCF level using the code GAMESS.^(a) Present results are compared with those of Bluhme, et al.^(b) Progress on our work with the targets N2 and O2 will be discussed and with present results for CO. It is significant that CO and N2 are very similar, but that CO gives a richer mass spectrum because the atomic cations are experimentally distinguishable from the molecular dication. ^(a) M. W. Schmidt, et al., J. Comput. Chem. 14, 1347 (1993). ^(b) H. Bluhme, et al., J. Phys. B 32, 5825 (1999).

  14. A low-energy antiproton detector prototype for AFIS

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Lingxin; Greenwald, Daniel; Hahn, Alexander; Hauptmann, Philipp; Konorov, Igor; Losekamm, Martin; Paul, Stephan; Poeschl, Thomas; Renker, Dieter [Technische Universitaet Muenchen (Germany)

    2014-07-01

    Antiprotons are produced in interactions of primary cosmic rays with earth's exosphere, where a fraction of them will be confined in the geomagnetic field in the inner van Allen Belt. The antiproton-to-proton flux ratio predicted by theory is in good agreement with recent results from the South Atlantic Anomaly (SAA) published by the PAMELA collaboration. We have designed the AFIS (Antiproton Flux in Space) project in order to extend the measurable range of antiprotons towards the low-energy region. In scope of this project a small antiproton detector consisting of scintillating fibers and silicon photomultipliers is being developed as payload for a CubeSat traversing the SAA in Low Earth Orbit. For the proof of concept we have built a prototype called ''CubeZero'' which completed its first test using pion and proton beams at PSI, Switzerland. Our primary goal was to investigate on the performance of tracking and Bragg peak identification in hardware and software. Analysis of detector performance based on data taken during this beam test is presented in this talk.

  15. Low-energy beam transport using space-charge lenses

    International Nuclear Information System (INIS)

    Meusel, O.; Bechtold, A.; Pozimski, J.; Ratzinger, U.; Schempp, A.; Klein, H.

    2005-01-01

    Space-charge lenses (SCL) of the Gabor type provide strong cylinder symmetric focusing for low-energy ion beams using a confined nonneutral plasma. They need modest magnetic and electrostatic field strength and provide a short installation length when compared to conventional LEBT-lenses like quadrupoles and magnetic solenoids. The density distribution of the enclosed space charge within the Gabor lens is given by the confinement in transverse and longitudinal directions. In the case of a positive ion beam, the space charge of the confined electron cloud may cause an overcompensation of the ion beam space-charge force and consequently focuses the beam. To investigate the capabilities of an SCL double-lens system for ion beam into an RFQ, a test injector was installed at IAP and put into operation successfully. Furthermore, to study the focusing capabilities of this lens at beam energies up to 500 keV, a high-field Gabor lens was built and installed downstream of the RFQ. Experimental results of the beam injection into the RFQ are presented as well as those of these first bunched beam-focusing tests with the 110 A keV He + beam

  16. Modelling interaction cross sections for intermediate and low energy ions

    International Nuclear Information System (INIS)

    Toburen, L.H.; Shinpaugh, J.L.; Justiniano, E.L.B.

    2002-01-01

    When charged particles slow in tissue they undergo electron capture and loss processes than can have profound effects on subsequent interaction cross sections. Although a large amount of data exists for the interaction of bare charged particles with atoms and molecules, few experiments have been reported for these 'dressed' particles. Projectile electrons contribute to an impact-parameter-dependent screening of the projectile charge that precludes straightforward scaling of energy loss cross sections from those of bare charged particles. The objective of this work is to develop an analytical model for the energy-loss-dependent effects of screening on differential ionisation cross sections that can be used in track structure calculations for high LET ions. As a first step a model of differential ionisation cross sections for bare ions has been combined with a simple screening model to explore cross sections for intermediate and low energy dressed ions in collisions with atomic and molecular gas targets. The model is described briefly and preliminary results compared to measured electron energy spectra. (author)

  17. Shape resonances in low-energy-electron collisions with halopyrimidines

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Alessandra Souza; Bettega, Márcio H. F., E-mail: bettega@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná (Brazil)

    2013-12-07

    We report calculated cross sections for elastic collisions of low-energy electrons with halopyrimidines, namely, 2-chloro, 2-bromo, and 5-bromopyrimidine. We employed the Schwinger multichannel method with pseudopotentials to compute the cross sections in the static-exchange and static-exchange plus polarization levels of approximation for energies up to 10 eV. We found four shape resonances for each molecule: three of π* nature localized on the ring and one of σ* nature localized along the carbon–halogen bond. We compared the calculated positions of the resonances with the electron transmission spectroscopy data measured by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)]. In general the agreement between theory and experiment is good. In particular, our results show the existence of a π* temporary anion state of A{sub 2} symmetry for all three halopyrimidines, in agreement with the dissociative electron attachment spectra also reported by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)].

  18. High-Resolution Measurements of Low-Energy Conversion Electrons

    CERN Multimedia

    Gizon, A; Putaux, J

    2002-01-01

    Measurements of low-energy internal conversion electrons have been performed with high energy resolution in some N = 105 odd and odd-odd nuclei using a semi-circular spectrograph associated to a specific tape transport system. These experiments aimed to answer the following questions~: \\begin{itemize} \\item Do M3 isomeric transitions exist in $^{183}$Pt and $^{181}$Os, isotones of $^{184}$Au~? \\item Are the neutron configurations proposed to describe the isomeric and ground states of $^{184}$Au right or wrong~? \\item Does it exist an isomeric state in $^{182}$Ir, isotone of $^{181}$Os, $^{183}$Pt and $^{184}$Au~? \\item What are the spin and parity values of the excited states of $^{182}$Ir~? \\end{itemize} In $^{183}$Pt, the 35.0 keV M3 isomeric transition has been clearly observed and the reduced transition probability has been determined. The deduced hindrance factor is close to that observed in the neighbouring odd-odd $^{184}$Au nucleus. This confirms the neutron configurations previously proposed for the ...

  19. Low-energy charge transfer excitations in NiO

    International Nuclear Information System (INIS)

    Sokolov, V I; Yermakov, A Ye; Uimin, M A; Gruzdev, N B; Pustovarov, V A; Churmanov, V N; Ivanov, V Yu; Sokolov, P S; Baranov, A N; Moskvin, A S

    2012-01-01

    Comparative analysis of photoluminescence (PL) and photoluminescence excitation (PLE) spectra of NiO poly- and nanocrystals in the spectral range 2-5.5 eV reveals two PLE bands peaked near 3.7 and 4.6 eV with a dramatic rise in the low-temperature PLE spectral weight of the 3.7 eV PLE band in the nanocrystalline NiO as compared with its polycrystalline counterpart. In frames of a cluster model approach we assign the 3.7 eV PLE band to the low-energy bulk-forbidden p-d (t 1g (π)-e g ) charge transfer (CT) transition which becomes the allowed one in the nanocrystalline state while the 4.6 eV PLE band is related to a bulk allowed d-d (e g -e g ) CT transition scarcely susceptible to the nanocrystallization. The PLE spectroscopy of the nanocrystalline materials appears to be a novel informative technique for inspection of different CT transitions.

  20. The low-energy frontier of particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, Joerg [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-02-15

    Most embeddings of the Standard Model into a more unified theory, in particular the ones based on supergravity or superstrings, predict the existence of a hidden sector of particles which have only very weak interactions with the visible sector Standard Model particles. Some of these exotic particle candidates (such as e.g. ''axions'', ''axion-like particles'' and ''hidden U(1) gauge bosons'') may be very light, with masses in the sub-eV range, and have very weak interactions with photons. Correspondingly, these very weakly interacting sub-eV particles (WISPs) may lead to observable effects in experiments (as well as in astrophysical and cosmological observations) searching for light shining through a wall, for changes in laser polarisation, for non-linear processes in large electromagnetic fields and for deviations from Coulomb's law. We present the physics case and a status report of this emerging low-energy frontier of fundamental physics. (orig.)

  1. Low-energy particle treatment of GaAs surface

    International Nuclear Information System (INIS)

    Pincik, E.; Ivanco, J.; Brunner, R.; Jergel, M.; Falcony, C.; Ortega, L.; Kucera, J. M.

    2002-01-01

    The paper presents results of a complex study of surface properties of high-doped (2x10 18 cm -3 ) and semi-insulating GaAs after an interaction with the particles coming from low-energy ion sources such as RF plasma and ion beams. The virgin samples were mechano-chemically polished liquid-encapsulated Czochralski-grown GaAs (100) oriented wafers. The crystals were mounted on the grounded electrode (holder). The mixture Ar+H 2 as well as O 2 and CF 4 were used as working gases: In addition, a combination of two different in-situ exposures was applied, such as e.g. hydrogen and oxygen. Structural, electrical and optical properties of the exposed surfaces were investigated using X-ray diffraction at grazing incidence, quasi-static and high-frequency C-V curve measurements, deep-level transient spectroscopy, photo-reflectance, and photoluminescence. Plasma and ion beam exposures were performed in a commercial RF capacitively coupled plasma equipment SECON XPL-200P and a commercial LPAI device, respectively. The evolution of surface properties as a function of the pressure of working gas and the duration of exposure was observed. (Authors)

  2. Diagnostics for low energy buncher stability at PLF, Mumbai

    International Nuclear Information System (INIS)

    Pal, S.; Karande, J.N.; Dhumal, P.; Takke, A.N.; Nanal, V.; Pillay, R.G.

    2013-01-01

    The buncher system at Pelletron Linac Facility (PLF), Mumbai consists of room-temperature double-harmonic drift bunchers, situated at the entrance of the Pelletron accelerator and a superconducting cavity at the injection of the LINAC. Low energy (LE) bunchers operate at sub harmonic of the LINAC reference clock (∼150 MHz)) with a bunching efficiency ∼ 66% and a typical FWHM of 1.5 ns.The dark current between adjacent bunches is swept away by RF parallel plate sweeper situated at exit of the Pelletron operating at f/32. The transit time variation arising due to Pelletron terminal voltage fluctuations are compensated by locking the reference of the LE bunchers to the phase detector operating at f/4 and situated at the injection of the LINAC. For a stable injection in the LINAC, the LE bunchers, the sweeper and the phase detector need too be phase synchronized with the LINAC master clock. To achieve a better stability on the phase lock, detailed phase stability measurements of the RF subsystem consisting of various RF devices, which operate at different sub harmonic of LINAC clock (f/32, f/16, f/8, f/4 and f) have been carried out. It was observed that temperature instabilities, ground loops and poor RF/EMI shielding due to aging effects were responsible for the phase jitter and drifts. The long term drifts and phase noise in the RF control of the LE buncher system have been minimized to a level better than 50 ps. (author)

  3. Testing SO(10)-inspired leptogenesis with low energy neutrino experiments

    CERN Document Server

    Di Bari, Pasquale

    2011-01-01

    We extend the results of a previous analysis of ours showing that, when both heavy and light flavour effects are taken into account, successful minimal (type I + thermal) leptogenesis with SO(10)-inspired relations is possible. Barring fine tuned choices of the parameters, these relations enforce a hierarchical RH neutrino mass spectrum that results into a final asymmetry dominantly produced by the next-to-lightest RH neutrino decays (N_2 dominated leptogenesis). We present the constraints on the whole set of low energy neutrino parameters. Allowing a small misalignment between the Dirac basis and the charged lepton basis as in the quark sector, the allowed regions enlarge and the lower bound on the reheating temperature gets relaxed to values as low as ~ 10^10 GeV. It is confirmed that for normal ordering (NO) there are two allowed ranges of values for the lightest neutrino mass: m_1 \\simeq (1-5)\\times 10^-3 eV and m_1\\simeq (0.03-0.1) eV. For m_1\\lesssim 0.01 eV the allowed region in the plane theta_13-thet...

  4. Application of low energy electron beam to precoated steel plates

    International Nuclear Information System (INIS)

    Koshiishi, Kenji

    1989-01-01

    Recently in the fields of home electric appliances, machinery and equipment and interior building materials, the needs for the precoated steel plates having the design and function of high class increase rapidly. In order to cope with such needs, the authors have advanced the examination on the application of electron beam hardening technology to precoated steel plates, and developed the precoated steel plates of high grade and high design 'Super Tecstar EB Series' by utilizing low energy electron beam. The features of this process are (1) hardening can be done at room temperature in a short time-thermally weak films can be adhered, (2) high energy irradiation-the hardening of thick enamel coating and the adhesion of colored films are feasible, (3) the use of monomers of low molecular weight-by high crosslinking, the performance of high sharpness, high hardness, anti-contamination property and so on can be given. The application to precoated steel plate production process is the coating and curing of electron beam hardening type paints, the coating of films with electron beam hardening type adhesives, and the reforming of surface polymer layers by impregnating monomers and causing graft polymerization with electron beam irradiation. The outline of the Super Tecstar EB Series is described. (K.I.)

  5. Observational techniques of gamma rays astronomy in low energy

    International Nuclear Information System (INIS)

    Costa, J.M. da.

    1982-02-01

    Due to the absorption of great part of the gamma-ray spectrum of cosmic origin, by the earth's atmosphere at heights above 20Km, gamma-ray astronomy achieved its full development only after the advent of the space age. Ballons and satellites are the space vehicles which have been used to transport gamma-ray telescopes to observational heights in the atmosphere, or out of it. The results of these experiments can determine the sources, the energy spectra and the intensities of the cosmic gamma-rays, and provide other important information of astrophysical interest. The detection of gamma-rays of cosmic origin is very difficult. The observational techniques used in gamma-ray astronomy are dependent on the energy range of the gamma-rays which one desires to detect. The most common telescopes of low energy gamma-ray astronomy (50KeV - 20MeV) use NaI(Tl) scintillators, or germanium diodes, as principal detectors, surrounded by an active shield (anticoincidence) of organic or inorganic scintillators. (Author) [pt

  6. Dose controlled low energy electron irradiator for biomolecular films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.; Tsering, Thupten [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

    2016-03-15

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  7. Low energy consumption vortex wave flow membrane bioreactor.

    Science.gov (United States)

    Wang, Zhiqiang; Dong, Weilong; Hu, Xiaohong; Sun, Tianyu; Wang, Tao; Sun, Youshan

    2017-11-01

    In order to reduce the energy consumption and membrane fouling of the conventional membrane bioreactor (MBR), a kind of low energy consumption vortex wave flow MBR was exploited based on the combination of biofilm process and membrane filtration process, as well as the vortex wave flow technique. The experimental results showed that the vortex wave flow state in the membrane module could be formed when the Reynolds number (Re) of liquid was adjusted between 450 and 1,050, and the membrane flux declined more slowly in the vortex wave flow state than those in the laminar flow state and turbulent flow state. The MBR system was used to treat domestic wastewater under the condition of vortex wave flow state for 30 days. The results showed that the removal efficiency for CODcr and NH 3 -N was 82% and 98% respectively, and the permeate quality met the requirement of 'Water quality standard for urban miscellaneous water consumption (GB/T 18920-2002)'. Analysis of the energy consumption of the MBR showed that the average energy consumption was 1.90 ± 0.55 kWh/m 3 (permeate), which was only two thirds of conventional MBR energy consumption.

  8. Dynamics of anion-molecule reactions at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Mikosch, J.

    2007-11-15

    Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S{sub N}2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S{sub N}2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S{sub N}2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S{sub N}2 mechanism involving CH{sub 3}-rotation. (orig.)

  9. Latest version of the Munich pulsed low energy positron system

    International Nuclear Information System (INIS)

    Bauer-Kugelmann, W.; Sperr, P.; Koegel, G.; Triftshaeuser, W.

    2001-01-01

    Further improvements of the Munich pulsed low energy positron system have been performed. A new chopper, configured as a double plate deflection system with an external resonator and a new buncher working like a classical double gap buncher, are implemented. The complete rf-power electronic was redesigned and operates now at an overall master-frequency of 50 MHz for all bunching and chopping components. A new target station with an enlarged Faraday cage is installed. The sample temperature is variable between 30 K and 600 K. Up to ten samples can be stored in a magazine and transferred under vacuum conditions to the measuring position. With a primary source of 30 mCi 22 Na a count rate of up to 4 kHz can be achieved with a peak-to-background ratio of 3000:1. This ratio can be further improved by the use of a Wien filter. A beam diameter of about 2 mm was determined. The total time resolution (pulsing plus detector system) is 250 ps (FWHM). (orig.)

  10. Reassessing a proposed low-energy strategy for the UK

    International Nuclear Information System (INIS)

    Kumar, S.; Taylor, R.; Probert, D.

    1999-01-01

    Predictions, as made in Leach et al. (A low-energy strategy for the United Kingdom. Science Reviews Ltd., Austria: International Institute for Environment and Development, 1979.) have been compared with actual values for subsequent years. Their disparities are discussed, together with the associated lessons. It would have been unreasonable to expect the 1979 predictive procedure to anticipate the 'dash for gas', but it can be realised in retrospect that greater emphasis should have been placed on the likely increasing concern (of successive governments) with environmental protection. In any strategy, the main mechanism (within a government's control) to achieve energy thrift is to raise the unit prices for (i) all fossil fuels and electricity derived from them and especially for (ii) polluting fuels for private cars and aircraft. These measures would simultaneously reduce the overall rate of environmental degradation. There should also be more introductory subsidies, provided by the state, for the implementation of all energy-thrift measures and equipment (e.g. combined heat-and-power plant), that satisfy the criterion of achieving a pay-back period of less than 7 years. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Rydberg phases of Hydrogen and low energy nuclear reactions

    Science.gov (United States)

    Olafsson, Sveinn; Holmlid, Leif

    2016-03-01

    For over the last 26 years the science of cold fusion/LENR has been researched around the world with slow pace of progress. Modest quantity of excess heat and signatures of nuclear transmutation and helium production have been confirmed in experiments and theoretical work has only resulted in a large flora of inadequate theoretical scenarios. Here we review current state of research in Rydberg matter of Hydrogen that is showing strong signature of nuclear processes. In the presentation experimental behavior of Rydberg matter of hydrogen is described. An extensive collaboration effort of surface physics, catalysis, atomic physics, solid state physics, nuclear physics and quantum information is need to tackle the surprising experimental results that have so far been obtained. Rydberg matter of Hydrogen is the only known state of matter that is able to bring huge collection of protons to so short distances and for so long time that tunneling becomes a reasonable process for making low energy nuclear reactions. Nuclear quantum entanglement can also become realistic process at theses conditions.

  12. Theories of Variable Mass Particles and Low Energy Nuclear Phenomena

    Science.gov (United States)

    Davidson, Mark

    2014-02-01

    Variable particle masses have sometimes been invoked to explain observed anomalies in low energy nuclear reactions (LENR). Such behavior has never been observed directly, and is not considered possible in theoretical nuclear physics. Nevertheless, there are covariant off-mass-shell theories of relativistic particle dynamics, based on works by Fock, Stueckelberg, Feynman, Greenberger, Horwitz, and others. We review some of these and we also consider virtual particles that arise in conventional Feynman diagrams in relativistic field theories. Effective Lagrangian models incorporating variable mass particle theories might be useful in describing anomalous nuclear reactions by combining mass shifts together with resonant tunneling and other effects. A detailed model for resonant fusion in a deuterium molecule with off-shell deuterons and electrons is presented as an example. Experimental means of observing such off-shell behavior directly, if it exists, is proposed and described. Brief explanations for elemental transmutation and formation of micro-craters are also given, and an alternative mechanism for the mass shift in the Widom-Larsen theory is presented. If variable mass theories were to find experimental support from LENR, then they would undoubtedly have important implications for the foundations of quantum mechanics, and practical applications may arise.

  13. Resonant Electromagnetic Interaction in Low Energy Nuclear Reactions

    Science.gov (United States)

    Chubb, Scott

    2008-03-01

    Basic ideas about how resonant electromagnetic interaction (EMI) can take place in finite solids are reviewed. These ideas not only provide a basis for conventional, electron energy band theory (which explains charge and heat transport in solids), but they also explain how through finite size effects, it is possible to create many of the kinds of effects envisioned by Giuliano Preparata. The underlying formalism predicts that the orientation of the external fields in the SPAWAR protocolootnotetextKrivit, Steven B., New Energy Times, 2007, issue 21, item 10. http://newenergytimes.com/news/2007/NET21.htm^,ootnotetextSzpak, S.; Mosier-Boss, P.A.; Gordon, F.E. Further evidence of nuclear reactions in the Pd lattice: emission of charged particles. Naturwissenschaften 94,511(2007)..has direct bearing on the emission of high-energy particles. Resonant EMI also implies that nano-scale solids, of a particular size, provide an optimal environment for initiating Low Energy Nuclear Reactions (LENR) in the PdD system.

  14. Studies on functional polymer films utilizing low energy electron beam

    International Nuclear Information System (INIS)

    Ando, Masayuki

    1992-01-01

    Also in adhesives and tackifiers, with the expansion of the fields of application, the required characteristics have become high grade and complex. As one of them, the instantaneous hardening of adhesives can be taken up. In the field of lamination works, the low energy type electron beam accelerators having the linear filament of accelerating voltage below 300 kV were developed in 1970s, and the interest in the development of electron beam-handened adhesives has heightend. The authors have carried out research aiming at heightening the functions of the polymer films obtained by electron beam hardening reaction, and developed the adhesives. In this report, the features of electron beam hardening reaction, the structure and properties of electron beam-hardened polymer films and the molecular design of electron beam-hardened monomer oligomers are described. The feature of electron beam hardening reaction is the cross-linking of high degree as the structure of oligomers is maintained. By controlling the structure at the time of electron beam hardening, the heightening of the functions of electron beam-hardened polymer films is feasible. (K.I.)

  15. Photon strength and the low-energy enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeking, M. [iThemba LABS, P.O. Box 722, Somerset West 7129 (South Africa); Bernstein, L. A.; Bleuel, D. L.; Burke, J. T.; Hatarik, R.; Lesher, S. R.; Scielzo, N. D. [Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Krtička, M. [Faculty of Mathematics and Physics, Charles University, V Holešovickách 2, Prague 8 (Czech Republic); Allmond, J. M. [Department of Physics, University of Richmond, Virginia 23173 (United States); Basunia, M. S.; Fallon, P.; Firestone, R. B.; Lake, P. T.; Lee, I-Y.; Paschalis, S.; Petri, M.; Phair, L. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Goldblum, B. L. [Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)

    2014-08-14

    Several measurements in medium mass nuclei have reported a low-energy enhancement in the photon strength function. Although, much effort has been invested in unraveling the mysteries of this effect, its physical origin is still not conclusively understood. Here, a completely model-independent experimental approach to investigate the existence of this enhancement is presented. The experiment was designed to study statistical feeding from the quasi-continuum (below the neutron separation energy) to individual low-lying discrete levels in {sup 95}Mo produced in the (d, p) reaction. A key aspect to successfully study gamma decay from the region of high-level density is the detection and extraction of correlated particle-gamma-gamma events which was accomplished using an array of Clover HPGe detectors and large area annular silicon detectors. The entrance channel excitation energy into the residual nucleus produced in the reaction was inferred from the detected proton energies in the silicon detectors. Gating on gamma-transitions originating from low-lying discrete levels specifies the state fed by statistical gamma-rays. Any particle-gamma-gamma event in combination with specific energy sum requirements ensures a clean and unambiguous determination of the initial and final state of the observed gamma rays. With these requirements the statistical feeding to individual discrete levels is extracted on an event-by-event basis. The results are presented and compared to {sup 95}Mo photon strength function data measured at the University of Oslo.

  16. Effective low-energy Hamiltonians for interacting nanostructures

    Science.gov (United States)

    Kinza, Michael; Ortloff, Jutta; Honerkamp, Carsten

    2010-10-01

    We present a functional renormalization group (fRG) treatment of trigonal graphene nanodisks and composites thereof, modeled by finite-size Hubbard-like Hamiltonians with honeycomb lattice structure. At half filling, the noninteracting spectrum of these structures contains a certain number of half-filled states at the Fermi level. For the case of trigonal nanodisks, including interactions between these degenerate states was argued to lead to a large ground state spin with potential spintronics applications [M. Ezawa, Eur. Phys. J. B 67, 543 (2009)10.1140/epjb/e2009-00041-7]. Here we perform a systematic fRG flow where the excited single-particle states are integrated out with a decreasing energy cutoff, yielding a renormalized low-energy Hamiltonian for the zero-energy states that includes effects of the excited levels. The numerical implementation corroborates the results obtained with a simpler Hartree-Fock treatment of the interaction effects within the zero-energy states only. In particular, for trigonal nanodisks the degeneracy of the one-particle-states with zero energy turns out to be protected against influences of the higher levels. As an explanation, we give a general argument that within this fRG scheme the zero-energy degeneracy remains unsplit under quite general conditions and for any size of the trigonal nanodisk. We also discuss a second class of nanostructures, bow-tie-shaped systems, where the zero-energy states are not protected.

  17. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Aoki, Y. [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); Bernard, C. [Washington University, Department of Physics, Saint Louis, MO (United States); Blum, T. [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); University of Connecticut, Physics Department, Storrs, CT (United States); Colangelo, G.; Leutwyler, H.; Necco, S.; Wenger, U. [Institut fuer theoretische Physik, Universitaet Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland); Della Morte, M. [University of Southern Denmark, CP3-Origins and Danish IAS, Odense M (Denmark); IFIC (CSIC), Paterna (Spain); Duerr, S. [Bergische Universitaet Wuppertal, Wuppertal (Germany); Juelich Supercomputing Center, Juelich (Germany); El-Khadra, A.X. [University of Illinois, Department of Physics, Urbana, IL (United States); Fukaya, H.; Onogi, T. [Osaka University, Department of Physics, Osaka (Japan); Horsley, R. [University of Edinburgh, School of Physics, Edinburgh (United Kingdom); Juettner, A.; Sachrajda, C.T. [University of Southampton, School of Physics and Astronomy, Southampton (United Kingdom); Kaneko, T. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan); Laiho, J. [University of Glasgow, SUPA, Department of Physics and Astronomy, Glasgow (United Kingdom); Syracuse University, Department of Physics, Syracuse, New York (United States); Lellouch, L. [Aix-Marseille Universite, CNRS, CPT, UMR 7332, Marseille (France); Universite de Toulon, CNRS, CPT, UMR 7332, La Garde (France); Lubicz, V. [Universita Roma Tre, Dipartimento di Matematica e Fisica, Rome (Italy); Sezione di Roma Tre, INFN, Rome (Italy); Lunghi, E. [Indiana University, Physics Department, Bloomington, IN (United States); Pena, C. [Universidad Autonoma de Madrid, Instituto de Fisica Teorica UAM/CSIC and Departamento de Fisica Teorica, Madrid (Spain); Sharpe, S.R. [University of Washington, Physics Department, Seattle, WA (United States); Simula, S. [Sezione di Roma Tre, INFN, Rome (Italy); Sommer, R. [NIC rate at DESY, Zeuthen (Germany); Water, R.S.V. de [Fermi National Accelerator Laboratory, Batavia, IL (United States); Vladikas, A. [Universita di Roma Tor Vergata, INFN, Sezione di Tor Vergata, c/o Dipartimento di Fisica, Rome (Italy); Wittig, H. [University of Mainz, PRISMA Cluster of Excellence, Institut fuer Kernphysik and Helmholtz Institute Mainz, Mainz (Germany); Collaboration: FLAG Working Group

    2014-09-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the lightquark masses, the form factor f{sub +}(0), arising in semileptonic K → π transition at zero momentum transfer, as well as the decay-constant ratio f{sub K}/f{sub π} of decay constants and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} andSU(3)L{sub L} x SU(3){sub R} Chiral Perturbation Theory and review the determination of the BK parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, we focus here on D- and B-meson decay constants, form factors, and mixing parameters, since these are most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. In addition we review the status of lattice determinations of the strong coupling constant α{sub s}. (orig.)

  18. Can Low Energy Electrons Affect High Energy Physics Accelerators?

    International Nuclear Information System (INIS)

    Cimino, Roberto

    2004-01-01

    The properties of the electrons participating in the build up of an electron cloud (EC) inside the beam-pipe have become an increasingly important issue for present and future accelerators whose performance may be limited by this effect. The EC formation and evolution are determined by the wall-surface properties of the accelerator vacuum chamber. Thus, the accurate modeling of these surface properties is an indispensible input to simulation codes aimed at the correct prediction of build-up thresholds, electron-induced instability or EC heat load. In this letter, we present the results of surface measurements performed on a prototype of the beam screen adopted for the Large Hadron Collider (LHC), which presently is under construction at CERN. We have measured the total secondary electron yield (SEY) as well as the related energy distribution curves (EDC) of the secondary electrons as a function of incident electron energy. Attention has been paid, for the first time in this context, to the probability at which low-energy electrons (<∼ 20 eV) impacting on the wall create secondaries or are elastically reflected. It is shown that the ratio of reflected to true-secondary electrons increases for decreasing energy and that the SEY approaches unity in the limit of zero primary electron energy

  19. E1 and M1 strength functions at low energy

    Science.gov (United States)

    Schwengner, Ronald; Massarczyk, Ralph; Bemmerer, Daniel; Beyer, Roland; Junghans, Arnd R.; Kögler, Toni; Rusev, Gencho; Tonchev, Anton P.; Tornow, Werner; Wagner, Andreas

    2017-09-01

    We report photon-scattering experiments using bremsstrahlung at the γELBE facility of Helmholtz-Zentrum Dresden-Rossendorf and using quasi-monoenergetic, polarized γ beams at the HIγS facility of the Triangle Universities Nuclear Laboratory in Durham. To deduce the photoabsorption cross sections at high excitation energy and high level density, unresolved strength in the quasicontinuum of nuclear states has been taken into account. In the analysis of the spectra measured by using bremsstrahlung at γELBE, we perform simulations of statistical γ-ray cascades using the code γDEX to estimate intensities of inelastic transitions to low-lying excited states. Simulated average branching ratios are compared with model-independent branching ratios obtained from spectra measured by using monoenergetic γ beams at HIγS. E1 strength in the energy region of the pygmy dipole resonance is discussed in nuclei around mass 90 and in xenon isotopes. M1 strength in the region of the spin-flip resonance is also considered for xenon isotopes. The dipole strength function of 74Ge deduced from γELBE experiments is compared with the one obtained from experiments at the Oslo Cyclotron Laboratory. The low-energy upbend seen in the Oslo data is interpreted as M1 strength on the basis of shell-model calculations.

  20. E1 and M1 strength functions at low energy

    Directory of Open Access Journals (Sweden)

    Schwengner Ronald

    2017-01-01

    Full Text Available We report photon-scattering experiments using bremsstrahlung at the γELBE facility of Helmholtz-Zentrum Dresden-Rossendorf and using quasi-monoenergetic, polarized γ beams at the HIγS facility of the Triangle Universities Nuclear Laboratory in Durham. To deduce the photoabsorption cross sections at high excitation energy and high level density, unresolved strength in the quasicontinuum of nuclear states has been taken into account. In the analysis of the spectra measured by using bremsstrahlung at γELBE, we perform simulations of statistical γ-ray cascades using the code γDEX to estimate intensities of inelastic transitions to low-lying excited states. Simulated average branching ratios are compared with model-independent branching ratios obtained from spectra measured by using monoenergetic γ beams at HIγS. E1 strength in the energy region of the pygmy dipole resonance is discussed in nuclei around mass 90 and in xenon isotopes. M1 strength in the region of the spin-flip resonance is also considered for xenon isotopes. The dipole strength function of 74Ge deduced from γELBE experiments is compared with the one obtained from experiments at the Oslo Cyclotron Laboratory. The low-energy upbend seen in the Oslo data is interpreted as M1 strength on the basis of shell-model calculations.

  1. Early Forest Fire Detection Using Low Energy Hydrogen Sensors

    Directory of Open Access Journals (Sweden)

    Jürgen Müller

    2016-08-01

    Full Text Available The North-east German Lowlands is a region with one of the highest forest fire risks in Europe. In order to keep damage levels as low as possible, it is important to have an effective early warning system. Such a system is being developed on the basis of a hydrogen sensor, which makes it possible to detect a smouldering forest fire before the development of open flames. The prototype hydrogen sensor produced at the Humboldt University Berlin has a metal/ solid electrolyte/insulator/ semiconductor (MEIS structure, which allows cost-effective production. Due to the low energy consumption, an autarchic working unit could be installed in the forest. Field trials have shown that it is possible to identify a forest fire in its early stages when hydrogen concentrations are still low. A significant change in the signal due to a fire was measured at a distance of about 100m. In view of the potential impacts of climate change, the innovative pre-ignition warning system is an important early diagnosis and monitoring module for the protection of the forests.

  2. A Monte Carlo track structure code for low energy protons

    CERN Document Server

    Endo, S; Nikjoo, H; Uehara, S; Hoshi, M; Ishikawa, M; Shizuma, K

    2002-01-01

    A code is described for simulation of protons (100 eV to 10 MeV) track structure in water vapor. The code simulates molecular interaction by interaction for the transport of primary ions and secondary electrons in the form of ionizations and excitations. When a low velocity ion collides with the atoms or molecules of a target, the ion may also capture or lose electrons. The probabilities for these processes are described by the quantity cross-section. Although proton track simulation at energies above Bragg peak (>0.3 MeV) has been achieved to a high degree of precision, simulations at energies near or below the Bragg peak have only been attempted recently because of the lack of relevant cross-section data. As the hydrogen atom has a different ionization cross-section from that of a proton, charge exchange processes need to be considered in order to calculate stopping power for low energy protons. In this paper, we have used state-of-the-art Monte Carlo track simulation techniques, in conjunction with the pub...

  3. Low energy class 1 typehouses according to the Danish building regulations

    DEFF Research Database (Denmark)

    Rose, Jørgen; Kragh, Jesper; Svendsen, Svend

    2008-01-01

    In 2005 the Danish Building regulations introduced two low energy classes for buildings in addition to tightened minimum requirements. The low energy class 1 and low energy class 2 correspond to total energy use, i.e. energy use for heating, ventilation, cooling and domestic hot water, as 50......% and 75% of the minimum requirement respectively. The main purpose of introducing the low energy classes were to further support and encourage the development of low energy buildings in Denmark. In 2010 it is expected that demands in the Building Regulations are tightened by 25-30% and in 2015...... it is expected that the minimum demand will correspond to the low energy class 1 demands of today. In order to secure this development in the building regulations, it is essential to support the development of low energy solutions and demonstrate that the goal is well within reach of the Danish building industry...

  4. Calculation of W for low energy electrons in tissue-equivalent gas. [<10 keV

    Energy Technology Data Exchange (ETDEWEB)

    Dayashankar, [Bhabha Atomic Research Centre, Bombay (India). Div. of Radiation Protection

    1977-11-01

    The mean energy expended per ion pair formed (W-value) in the tissue-equivalent gas for incident electrons of energy up to 10 keV has been calculated in the continuous slowing-down approximation. The effect of secondary and tertiary electrons has been considered by utilizing recent measurements of Opal et al., (1971, J. Chem. Phys., 55,4100) on the energy spectra of low-energy secondary electrons and the Mott formula for the spectra of high-energy secondaries. The results, which are provisional in nature due to the limitations on the accuracy of the input cross-section data and the neglect of the discrete nature of energy loss process, are compared with the available measurements.

  5. In vivo measurements background estimation of low energy trough the anthropometric parameters correlation and with the potassium body content

    International Nuclear Information System (INIS)

    Sousa, Wanderson O.; Dantas, Ana Leticia A.; Dantas, Bernardo M.

    2002-01-01

    The occupational monitoring of individuals with potential risk of incorporation of radionuclides such as Am-241, U-238, U-235 and Ra-226 by inhalation in workplaces where particulates in suspension can be present, is frequently performed by in vivo measurements of the lungs. The activity calculation involves a comparison of the acquired spectrum with a reference spectrum. The accuracy of the background prediction is critical when the expected activities are close to the minimum detection limit. This is the case of occupational monitoring where most of the activities observed are bellow or very close the detection limit. The use of a inappropriate reference spectrum can lead to false-positive or false-negative results. The variability of potassium content among individuals in one of the major factors in the fluctuation of the count rate in the low energy region of the spectrum. This contribution is associated with the Compton effect due to the interaction of 1461 keV photons emitted by K-40. In order to verify the correlation between the background count rate in the various regions of interest of the low energy spectra with the potassium mass in the body it was designed an experimental procedure consisting of measuring a thoracic phantom containing known amounts of potassium. The strong correlation observed motivated the continuity of this work which consisted in the analysis of real low energy in vivo spectra with the aim of verifying the correlation between anthropometric parameters (sex, age, weight and height) and the count rates in the region of K-40 with the count rates in the low energy regions of interest. The results obtained show a significant correlation between the selected parameters with the count rate of the background. This allows a more reliable estimation of activity of low energy radionuclides in individuals monitored through in vivo measurements. The occupational monitoring. (author)

  6. Reactions induced by low energy electrons in cryogenic films

    International Nuclear Information System (INIS)

    Bass, A.D.; Sanche, L.

    2003-01-01

    We review recent research on reactions (including dissociation) initiated by low-energy electron bombardment of monolayer and multilayer molecular solids at cryogenic temperatures. With incident electrons of energies below 20 eV, dissociation is observed by the electron stimulated desorption (ESD) of anions from target films and is attributed to the processes of dissociative electron attachment (DEA) and to dipolar dissociation. It is shown that DEA to condensed molecules is sensitive to environmental factors such as the identity of co-adsorbed species and film morphology. The effects of image-charge induced polarization on cross-sections for DEA to CH3Cl are also discussed. Taking as examples, the electron-induced production of CO within multilayer films of methanol and acetone, it is shown that the detection of electronic excited states by high resolution electron energy loss spectroscopy can be used to monitor electron beam damage. In particular, the incident energy dependence of the CO indicates that below 19 eV, dissociation proceeds via the decay of transient negative ions (TNI) into electronically excited dissociative states. The electron induced dissociation of biomolecular targets is also considered, taking as examples the ribose analog tetrahydrofuran and DNA bases adenine and thymine, cytosine and guanine. The ESD of anions from such films also show dissociation via the formation of TNI. In multilayer molecular solids, fragment species resulting from dissociation, may react with neighboring molecules, as is demonstrated in anion ESD measurements from films containing O 2 and various hydrocarbon molecules. X-ray photoelectron spectroscopy measurements reported for electron irradiated monolayers of H 2 O and CF 4 on a Si - H passivated surface further show that DEA is an important initial step in the electron-induced chemisorption of fragment species

  7. Effect of projectile on incomplete fusion reactions at low energies

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2017-01-01

    Full Text Available Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n excess projectile 13C (as compared to 12C results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B and forward (F α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  8. Effect of projectile on incomplete fusion reactions at low energies

    Science.gov (United States)

    Sharma, Vijay R.; Shuaib, Mohd.; Yadav, Abhishek; Singh, Pushpendra P.; Sharma, Manoj K.; Kumar, R.; Singh, Devendra P.; Singh, B. P.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.; Prasad, R.

    2017-11-01

    Present work deals with the experimental studies of incomplete fusion reaction dynamics at energies as low as ≈ 4 - 7 MeV/A. Excitation functions populated via complete fusion and/or incomplete fusion processes in 12C+175Lu, and 13C+169Tm systems have been measured within the framework of PACE4 code. Data of excitation function measurements on comparison with different projectile-target combinations suggest the existence of ICF even at slightly above barrier energies where complete fusion (CF) is supposed to be the sole contributor, and further demonstrates strong projectile structure dependence of ICF. The incomplete fusion strength functions for 12C+175Lu, and 13C+169Tm systems are analyzed as a function of various physical parameters at a constant vrel ≈ 0.053c. It has been found that one neutron (1n) excess projectile 13C (as compared to 12C) results in less incomplete fusion contribution due to its relatively large negative α-Q-value, hence, α Q-value seems to be a reliable parameter to understand the ICF dynamics at low energies. In order to explore the reaction modes on the basis of their entry state spin population, the spin distribution of residues populated via CF and/or ICF in 16O+159Tb system has been done using particle-γ coincidence technique. CF-α and ICF-α channels have been identified from backward (B) and forward (F) α-gated γspectra, respectively. Reaction dependent decay patterns have been observed in different α emitting channels. The CF channels are found to be fed over a broad spin range, however, ICF-α channels was observed only for high-spin states. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states

  9. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto Univ. (Japan). Yukawa Inst. for Theoretical Physics; Aoki, Y. [Nagoya Univ. (Japan). Kobayashi-Maskawa Inst. for the Origin of Particles and the Universe; Brookhaven National Laboratory, Upton, NY (United States). RIKEN BNL Research Center; Becirevic, D. [Univ. Paris-Saclay, Orsay (France). CNRS; Collaboration: FLAG Working Group; and others

    2016-07-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f{sub +}(0), arising in the semileptonic K→π transition at zero momentum transfer, as well as the decay constant ratio f{sub K}/f{sub π} and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} and SU(3){sub L} x SU(3){sub R} Chiral Perturbation Theory. We review the determination of the B{sub K} parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m{sub c} and m{sub b} (also new compared to the previous review), as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α{sub s}.

  10. Vibrational excitation of D2 by low energy electrons

    International Nuclear Information System (INIS)

    Buckman, S.J.; Phelps, A.V.

    1985-01-01

    Excitation coefficients for the production of vibrationally exicted D 2 by low energy electrons have been determined from measurements of the intensity of infrared emission from mixtures of D 2 and small concentrations of CO 2 or CO. The measurements were made using the electron drift tube technique and covered electric field to gas density ratios (E/n) from (5 to 80) x 10 -21 V m 2 , corresponding to mean electron energies between 0.45 and 4.5 eV. The CO 2 and CO concentrations were chosen to allow efficient excitation transfer from the D 2 to the carbon containing molecule, but to minimize direct excitation of the CO 2 or CO. The measured infrared intensities were normalized to predicted values for N 2 --CO 2 and N 2 --CO mixtures at E/n where the efficiency of vibrational excitation is known to be very close to 100%. The experimental excitation coefficients are in satisfactory agreement with predictions based on electron--D 2 cross sections at mean electron energies below 1 eV, but are about 50% too high at mean energies above about 2 eV. Application of the technique to H 2 did not yield useful vibrational excitation coefficients. The effective coefficients in H 2 --CO 2 mixtures were a factor of about 3 times the predicted values. For our H 2 --CO mixtures the excitation of CO via excitation transfer from H 2 is small compared to direct electron excitation of CO molecules. Published experiments and theories on electron--H 2 and electron--D 2 collisions are reviewed to obtain the cross sections used in the predictions

  11. Leptogenesis and low energy CP-violation in neutrino physics

    International Nuclear Information System (INIS)

    Pascoli, S.; Petcov, S.T.; Riotto, A.

    2007-01-01

    Taking into account the recent progress in the understanding of the lepton flavor effects in leptogenesis, we investigate in detail the possibility that the CP-violation necessary for the generation of the baryon asymmetry of the Universe is due exclusively to the Dirac and/or Majorana CP-violating phases in the PMNS neutrino mixing matrix U, and thus is directly related to the low energy CP-violation in the lepton sector (e.g., in neutrino oscillations, etc.). We first derive the conditions of CP-invariance of the neutrino Yukawa couplings λ in the see-saw Lagrangian, and of the complex orthogonal matrix R in the 'orthogonal' parametrization of λ. We show, e.g. that under certain conditions (i) real R and specific CP-conserving values of the Majorana and Dirac phases can imply CP-violation, and (ii) purely imaginary R does not necessarily imply breaking of CP-symmetry. We study in detail the case of hierarchical heavy Majorana neutrino mass spectrum, presenting results for three possible types of light neutrino mass spectrum: (i) normal hierarchical, (ii) inverted hierarchical, and (iii) quasi-degenerate. Results in the alternative case of quasi-degenerate in mass heavy Majorana neutrinos, are also derived. The minimal supersymmetric extension of the standard theory with right-handed Majorana neutrinos and see-saw mechanism of neutrino mass generation is discussed as well. We illustrate the possible correlations between the baryon asymmetry of the Universe and (i) the rephasing invariant J CP controlling the magnitude of CP-violation in neutrino oscillations, or (ii) the effective Majorana mass in neutrinoless double beta decay, in the cases when the only source of CP-violation is respectively the Dirac or the Majorana phases in the neutrino mixing matrix

  12. Detectors for low energy electron cooling in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, F. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-15

    Low-energy operation of RHIC is of particular interest to study the location of a possible critical point in the QCD phase diagram. The performance of RHIC at energies equal to or lower than 10 GV/nucleon is limited by nonlinearities, Intra-BeamScattering (IBS) processes and space-charge effects. To successfully address the luminosity and ion store lifetime limitations imposed by IBS, the method of electron cooling has been envisaged. During electron cooling processes electrons are injected along with the ion beam at the nominal ion bunch velocities. The velocity spread of the ion beam is reduced in all planes through Coulomb interactions between the cold electron beam and the ion beam. The electron cooling system proposed for RHIC will be the first of its kind to use bunched beams for the delivery of the electron bunches, and will therefore be accompanied by the necessary challenges. The designed electron cooler will be located in IP2. The electron bunches will be accelerated by a linac before being injected along side the ion beams. Thirty consecutive electron bunches will be injected to overlap with a single ion bunch. They will first cool the yellow beam before being extracted, turned by 180-degrees, and reinjected into the blue beam for cooling. As such, both the yellow and blue beams will be cooled by the same ion bunches. This will pose considerable challenges to ensure proper electron beam quality to cool the second ion beam. Furthermore, no ondulator will be used in the electron cooler so radiative recombination between the ions and the electrons will occur.

  13. Pattern formation on Ge by low energy ion beam erosion

    International Nuclear Information System (INIS)

    Teichmann, Marc; Lorbeer, Jan; Frost, Frank; Rauschenbach, Bernd; Ziberi, Bashkim

    2013-01-01

    Modification of nanoscale surface topography is inherent to low-energy ion beam erosion processes and is one of the most important fields of nanotechnology. In this report a comprehensive study of surface smoothing and self-organized pattern formation on Ge(100) by using different noble gases ion beam erosion is presented. The investigations focus on low ion energies (⩽ 2000 eV) and include the entire range of ion incidence angles. It is found that for ions (Ne, Ar) with masses lower than the mass of the Ge target atoms, no pattern formation occurs and surface smoothing is observed for all angles of ion incidence. In contrast, for erosion with higher mass ions (Kr, Xe), ripple formation starts at incidence angles of about 65° depending on ion energy. At smaller incident angles surface smoothing occurs again. Investigations of the surface dynamics for specific ion incidence angles by changing the ion fluence over two orders of magnitude gives a clear evidence for coarsening and faceting of the surface pattern. Both observations indicate that gradient-dependent sputtering and reflection of primary ions play crucial role in the pattern evolution, just at the lowest accessible fluences. The results are discussed in relation to recently proposed redistributive or stress-induced models for pattern formation. In addition, it is argued that a large angular variation of the sputter yield and reflected primary ions can significantly contribute to pattern formation and evolution as nonlinear and non-local processes as supported by simulation of sputtering and ion reflection. (paper)

  14. Properties of states of low energy on cosmological spacetimes

    International Nuclear Information System (INIS)

    Degner, Andreas

    2013-01-01

    The present thesis investigates properties of a class of physical states of the quantised scalar field in FRW spacetimes, namely the states of low energy (SLE's). These states are characterised by minimising the time-smeared energy density measured by an isotropic observer, where the smearing is performed with respect to a test function f of compact support. Furthermore, they share all spatial symmetries of the spacetime. Since SLE's are Hadamard states, expectations values of observables like the energy density can be rigorously defined via the so called point-splitting method. In a first step, this procedure is applied to the explicit calculation of the energy density in SLE's for the case of de Sitter space with flat spatial sections. In particular, the e ect of the choice of the mass m and the test function f is discussed. The obtained results motivate the question whether SLE's converge to a distinguished state (namely the Bunch Davies state) when the support of f is shifted to the infinite past. It is shown that this is indeed the case, even in the more general class of asymptotic de Sitter spacetimes, where an analogon of the Bunch Davies state can be defined. This result enables the interpretation of such distinguished states to be SLE's in the infinite past, independently of the form of the smearing function f. Finally, the role of SLE's for the semiclassical backreaction problem is discussed. We derive the semiclassical Friedmann equation in a perturbative approach over Minkowski space. This equation allows for a stability analysis of Minkowski space by the investigation of asymptotic properties of solutions. We also treat this problem using a numerical method.

  15. Review of lattice results concerning low-energy particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kyoto University, Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Aoki, Y. [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Becirevic, D. [Universite Paris-Sud, Universite Paris-Saclay, Laboratoire de Physique Theorique (UMR8627), CNRS, Orsay (France); Bernard, C. [Washington University, Department of Physics, Saint Louis, MO (United States); Blum, T. [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States); University of Connecticut, Physics Department, Storrs, CT (United States); Colangelo, G.; Leutwyler, H.; Wenger, U. [Universitaet Bern, Albert Einstein Center for Fundamental Physics, Institut fuer Theoretische Physik, Bern (Switzerland); Della Morte, M. [University of Southern Denmark, CP3-Origins and Danish IAS, Odense M (Denmark); IFIC (CSIC), Paterna (Spain); Dimopoulos, P. [Centro Fermi-Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi Compendio del Viminale, Rome (Italy); Universita di Roma Tor Vergata, c/o Dipartimento di Fisica, Rome (Italy); Duerr, S. [University of Wuppertal, Wuppertal (Germany); Juelich Supercomputing Center, Forschungszentrum Juelich, Juelich (Germany); Fukaya, H.; Onogi, T. [Osaka University, Department of Physics, Toyonaka, Osaka (Japan); Golterman, M. [San Francisco State University, Department of Physics and Astronomy, San Francisco, CA (United States); Gottlieb, Steven; Lunghi, E. [Indiana University, Department of Physics, Bloomington, IN (United States); Hashimoto, S.; Kaneko, T. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); The Graduate University for Advanced Studies (Sokendai), School of High Energy Accelerator Science, Tsukuba (Japan); Heller, U.M. [American Physical Society (APS), Ridge, NY (United States); Horsley, R. [University of Edinburgh, Higgs Centre for Theoretical Physics, School of Physics and Astronomy, Edinburgh (United Kingdom); Juettner, A.; Sachrajda, C.T. [University of Southampton, School of Physics and Astronomy, Southampton (United Kingdom); Lellouch, L. [CNRS, Aix-Marseille Universite, Universite de Toulon, Centre de Physique Theorique, UMR 7332, Marseille (France); Lin, C.J.D. [CNRS, Aix-Marseille Universite, Universite de Toulon, Centre de Physique Theorique, UMR 7332, Marseille (France); National Chiao-Tung University, Institute of Physics, Hsinchu (China); Lubicz, V. [Universita Roma Tre, Dipartimento di Matematica e Fisica, Rome (Italy); INFN, Sezione di Roma Tre, Rome (Italy); Mawhinney, R. [Columbia University, Physics Department, New York, NY (United States); Pena, C. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Sharpe, S.R. [University of Washington, Physics Department, Seattle, WA (United States); Simula, S. [INFN, Sezione di Roma Tre, Rome (Italy); Sommer, R. [DESY, John von Neumann Institute for Computing (NIC), Zeuthen (Germany); Vladikas, A. [Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); INFN, Rome (Italy); Wittig, H. [University of Mainz, PRISMA Cluster of Excellence, Institut fuer Kernphysik and Helmholtz Institute Mainz, Mainz (Germany); Collaboration: Flavour Lattice Averaging Group (FLAG)

    2017-02-15

    We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor f{sub +}(0), arising in the semileptonic K → π transition at zero momentum transfer, as well as the decay constant ratio f{sub K}/f{sub π} and its consequences for the CKM matrix elements V{sub us} and V{sub ud}. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2){sub L} x SU(2){sub R} and SU(3){sub L} x SU(3){sub R} Chiral Perturbation Theory. We review the determination of the B{sub K} parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for m{sub c} and m{sub b} (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant α{sub s}. (orig.)

  16. Properties of states of low energy on cosmological spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Degner, Andreas

    2013-01-15

    The present thesis investigates properties of a class of physical states of the quantised scalar field in FRW spacetimes, namely the states of low energy (SLE's). These states are characterised by minimising the time-smeared energy density measured by an isotropic observer, where the smearing is performed with respect to a test function f of compact support. Furthermore, they share all spatial symmetries of the spacetime. Since SLE's are Hadamard states, expectations values of observables like the energy density can be rigorously defined via the so called point-splitting method. In a first step, this procedure is applied to the explicit calculation of the energy density in SLE's for the case of de Sitter space with flat spatial sections. In particular, the e ect of the choice of the mass m and the test function f is discussed. The obtained results motivate the question whether SLE's converge to a distinguished state (namely the Bunch Davies state) when the support of f is shifted to the infinite past. It is shown that this is indeed the case, even in the more general class of asymptotic de Sitter spacetimes, where an analogon of the Bunch Davies state can be defined. This result enables the interpretation of such distinguished states to be SLE's in the infinite past, independently of the form of the smearing function f. Finally, the role of SLE's for the semiclassical backreaction problem is discussed. We derive the semiclassical Friedmann equation in a perturbative approach over Minkowski space. This equation allows for a stability analysis of Minkowski space by the investigation of asymptotic properties of solutions. We also treat this problem using a numerical method.

  17. Low energy electron-driven damage in biomolecules

    International Nuclear Information System (INIS)

    Sanche, L.

    2005-01-01

    The damage induced by the impact of low energy electrons (LEE) on biomolecules is reviewed from a radiobiological perspective with emphasis on transient anion formation. The major type of experiments, which measure the yields of fragments produced as a function of incident electron energy (0.1 - 30 eV), are briefly described. Theoretical advances are also summarized. Several examples are presented from the results of recent experiments performed in the gas-phase and on bio-molecular films bombarded with LEE under ultra-high vacuum conditions. These include the results obtained from DNA films and those obtained from the fragmentation of elementary components of the DNA molecule (i.e., the bases, sugar and phosphate group analogs and oligonucleotides) and of proteins (e.g. amino acids). By comparing the results from different experiments and theory, it is possible to determine fundamental mechanisms that are involved in the dissociation of the biomolecules and the production of single- and double-strand breaks in DNA. Below 15 eV, electron resonances (i.e., the formation of transient anions) play a dominant role in the fragmentation of all biomolecules investigated. These transient anions fragment molecules by decaying into dissociative electronically excited states or by dissociating into a stable anion and a neutral radical. These fragments can initiate further reactions within large biomolecules or with nearby molecules and thus cause more complex chemical damage. Dissociation of a transient anion within DNA may occur by direct electron attachment at the location of dissociation or by electron transfer from another subunit. Damage to DNA is dependent on the molecular environment, topology, type of counter ion, sequence context and chemical modifications. (author)

  18. Silicon passivation study under low energy electron irradiation conditions

    International Nuclear Information System (INIS)

    Cluzel, R.

    2010-01-01

    Backside illuminated thinned CMOS (Complementary Metal Oxide Semiconductor) imaging system is a technology developed to increase the signal to noise ratio and the sensibility of such sensors. This configuration is adapted to the electrons detection from the energy range of [1 - 12 keV]. The impinging electron creates by multiplication several hundreds of secondary electrons close to the surface. A P ++ highly-doped passivation layer of the rear face is required to reduce the secondary electron surface recombination rate. Thanks to the potential barrier induced by the P ++ layer, the passivation layer increases the collected charges number and so the sensor collection gain. The goal of this study is to develop some experimental methods in order to determine the effect of six different passivation processes on the collection gain. Beforehand, the energy profile deposited by an incident electron is studied with the combination of Monte-Carlo simulations and some analytical calculations. The final collection gain model shows that the mirror effect from the passivation layer is a key factor at high energies whereas the passivation layer has to be as thin as possible at low energies. A first experimental setup which consists in irradiating P ++ /N large diodes allows to study the passivation process impacts on the surface recombinations. Thanks to a second setup based on a single event upset directly on thinned CMOS sensor, passivation techniques are discriminated in term of mirror effect and the implied spreading charges. The doping atoms activation laser annealing is turn out to be a multiplication gain inhomogeneity source impacting directly the matrix uniformity. (author)

  19. Smartphone-Based Indoor Localization with Bluetooth Low Energy Beacons.

    Science.gov (United States)

    Zhuang, Yuan; Yang, Jun; Li, You; Qi, Longning; El-Sheimy, Naser

    2016-04-26

    Indoor wireless localization using Bluetooth Low Energy (BLE) beacons has attracted considerable attention after the release of the BLE protocol. In this paper, we propose an algorithm that uses the combination of channel-separate polynomial regression model (PRM), channel-separate fingerprinting (FP), outlier detection and extended Kalman filtering (EKF) for smartphone-based indoor localization with BLE beacons. The proposed algorithm uses FP and PRM to estimate the target's location and the distances between the target and BLE beacons respectively. We compare the performance of distance estimation that uses separate PRM for three advertisement channels (i.e., the separate strategy) with that use an aggregate PRM generated through the combination of information from all channels (i.e., the aggregate strategy). The performance of FP-based location estimation results of the separate strategy and the aggregate strategy are also compared. It was found that the separate strategy can provide higher accuracy; thus, it is preferred to adopt PRM and FP for each BLE advertisement channel separately. Furthermore, to enhance the robustness of the algorithm, a two-level outlier detection mechanism is designed. Distance and location estimates obtained from PRM and FP are passed to the first outlier detection to generate improved distance estimates for the EKF. After the EKF process, the second outlier detection algorithm based on statistical testing is further performed to remove the outliers. The proposed algorithm was evaluated by various field experiments. Results show that the proposed algorithm achieved the accuracy of EKF algorithm and 15.77% more accurate than EKF algorithm. With sparse deployment (1 beacon per 18 m), the proposed algorithm achieves the accuracies of EKF algorithm and 21.41% better than EKF algorithm. Therefore, the proposed algorithm is especially useful to improve the localization accuracy in environments with sparse beacon deployment.

  20. Mechanisms of emission of particles charged in 6Li + 6Li and 6Li + 10B reactions at low energies

    International Nuclear Information System (INIS)

    Quebert, Jean

    1964-01-01

    The lithium 6 nucleus is a projectile of interest to study nuclear reactions at low energy due to the possibility to obtain high heats of reaction, and to its structure which can play an important role in the projectile-target interaction. This research thesis focused on the study of two low-energy reactions provoked by lithium projectiles. These reactions are studied within the framework of the theoretical model of aggregates. The first part presents the experimental conditions of both reactions, reports the development and analysis of nuclear plates, and the transformation of a given type of particle histogram into a spectrum in the mass centre system. The next parts report the study of the 6 Li + 6 Li reaction (previous results, kinematic analysis, spectrum of secondary particles, theoretical analysis of results) and of the 6 Li + 10 B reaction (previous results, experimental results, study of the continuous spectrum of alpha particle, reaction mechanisms)

  1. Low Energy Electrons as Probing Tool for Astrochemical Reaction Mechanisms

    Science.gov (United States)

    Hendrik Bredehöft, Jan; Swiderek, Petra; Hamann, Thorben

    hitting anything solid, they will create secondary electrons. These electrons are in fact the energy source needed to run interstellar chemistry. Slow electrons can in principle trigger three different primary processes in a molecule. The first is ionisation by electron impact (EI), which is used to create ions in mass spectrometry. In this process an electron hits a molecule M and knocks an outer shell electron to create a cation. This occurs whenever the electron energy is above the ionisation threshold of the target molecule. Another possibility is the attachment of a slow electron to a molecule to create an anion. This can occur at sharply defined resonance energies specific to the molecule M. A third possibility is to excite the molecule M to a neutral state M∗ .[9] M + e- -> M+ + 2 e- (Electron impact ionisation) M + e- -> M- (Electron attachment) M + e- -> M∗ + e- (Neutral excitation) The created states M+ , M- and M∗ are usually not stable states so they very often dissociate into ions and radicals, which can then further react with neighbouring molecules to form new chemical species. In these chemical reactions some products can be formed even at very low temperatures that would otherwise require a lot of thermal energy and/or special catalysts. The formation of ethylamine from ethylene and ammonia by hydroamination is one such example. The reaction is characterized by a high activation barrier caused by the electronic repulsion between the electron density rich C=C double bound and the lone pair electrons of ammo-nia. The reaction also has a highly negative entropy, so it becomes less favourable at higher temperatures, ruling out heat as a means to facilitate the reaction. In classical chemistry this problem is overcome by the use of catalysts. Unfortunately there still is no general catalyst for this kind of reaction. Recently it was shown that the reaction can efficiently be induced by low energy electron radiation.[10] One of the reaction partners is

  2. LEAP [Low-Energy Antiproton]: A balloon-borne search for low-energy cosmic-ray antiprotons

    International Nuclear Information System (INIS)

    Moats, A.R.M.

    1989-01-01

    The LEAP (Low-Energy Antiproton) experiment is a search for cosmic-ray antiprotons in the 120 MeV to 1.2 GeV kinetic energy range. The motivation for this project was the result announced by Buffington et. al. (1981) that indicated an anomalously high antiproton flux below 300 MeV; this result has compelled theorists to propose sources of primary antiprotons above the small secondary antiproton flux produced by high energy cosmic-ray collisions with nuclei in the interstellar medium. LEAP consisted of the NMSU magnetic spectrometer, a time-of-flight system designed at Goddard Space Flight Center, two scintillation detectors, and a Cherenkov counter designed and built at the University of Arizona. Analysis of flight data performed by the high-energy astrophysics group at Goddard Space Flight Center revealed no antiproton candidates found in the 120 MeV to 360 MeV range; 3 possible antiproton candidate events were found in the 500 MeV to 1.2 GeV range in an analysis done here at the University of Arizona. However, since it will be necessary to sharpen the calibration on all of the LEAP systems in order to positively identify these events as antiprotons, only an upper limit has been determined at present. Thus, combining the analyses performed at the University of Arizona and Goddard Space Flight Center, 90% confidence upper limits of 3.5 x 10 -5 in the 120 MeV to 360 MeV range and 2.3 x 10 -4 in the 500 MeV to 1.2 GeV range for the antiproton/proton ratio is indicated by the LEAP results. LEAP disagrees sharply with the results of the Buffington group, indicating a low antiproton flux at these energies

  3. Differences between food group reports of low energy reporters and non-low energy reporters on a food frequency questionnaire

    Science.gov (United States)

    Millen, Amy E.; Tooze, Janet A.; Subar, Amy F.; Kahle, Lisa L.; Schatzkin, Arthur; Krebs-Smith, Susan M.

    2013-01-01

    Background Low-energy reporters (LERs) and non-LERs differ with respect to a number of characteristics, including self-reported intake of foods. Limited data exists investigating food intake differences with LERs identified using doubly labeled water (DLW). Objective In the Observing Protein and Energy Nutrition Study (September, 1999-March, 2000), differences were examined between food group reports of LERs and non-LERs on a food frequency questionnaire (FFQ) (n=440). Design LERs were identified using DLW. LERs' (n=220) and non-LERs' (n=220) reports of 43 food groups on the FFQ were examined in three ways: whether they reported consuming a food group (yes/no), how frequently they reported consuming it (times/day), and the reported portion size (small, medium, or large). Analyses were adjusted for total energy expenditure from DLW. Results LERs compared to non-LERs were less likely to report consumption for one food group among women (soft drinks/regular) and no food groups among men. Reported mean daily frequency of consumption was lower in LERs compared to non-LERs for 23 food groups among women and 24 food groups among men (18 food groups were similar in men and women). Additionally, reported mean portion sizes were smaller for LERs compared to non-LERs for 6 food groups among women and 5 food groups among men (3 food groups were similar in men and women). Results varied minimally by sex and body mass index (BMI). Conclusions LERs as compared to non-LERs were more likely to differ regarding their reported frequency of consumption of food groups than their reported consumption (yes/no) of the food groups or the food groups' reported portion sizes. Results did not vary greatly by sex or BMI. It still remains to be known whether improvement in questionnaire design or additional tools or methods would lead to a decrease in differential reporting due to LER status on an FFQ. PMID:19559136

  4. Identification and tracking of low energy spectator protons

    Energy Technology Data Exchange (ETDEWEB)

    Mussgiller, A.

    2007-07-20

    The present theses discusses the development, technical design and realization as well as the read-out electronics of a detection system for the identification and tracking of low energy spectator protons. With the knowledge of the four-momentum of such spectator protons it will be possible to use deuterium as an effective neutron target. Previous measurements with an early version of the detection system have already shown that this method works quite well to investigate for instance the {omega} or {eta}-meson production in proton-neutron collisions. Moreover, after the completion and installation of the polarized internal target (PIT) at ANKE, it will be even possible to engage in that field with double polarized experiments. To increase the luminosity the polarized target is equipped with an extended target cell. The described detection-system will provide the vertex reconstruction for this extended interaction region. In addition, it will act as an independent beam polarimeter at ANKE. The detection system consists of three layers of double-sided silicon strip detectors which are arranged in a telescope structure and placed inside the accelerator vacuum as close as 2 cm to the interaction region. The modular design of the electronics and the support structures for the detectors allows one to exchange detectors and electronics in a maximum flexible way. In a minimum configuration the telescope is equipped with two detectors, a thin ({approx} 69 {mu}m) double-sided Silicon strip detector as a first layer and a very thick ({>=} 5 mm) double-sided micro-structured Lithium-drifted Silicon detector as a second layer. With this arrangement it is possible to track and identify protons in a kinetic energy range from 2.5 MeV to 25 MeV. For deuterons this range for such a telescope configuration is from 4 MeV to 34 MeV. The performance concerning the energy determination and tracking is shown based on data taken during a beam-time in November of 2003. With the existing

  5. Smartphone-Based Indoor Localization with Bluetooth Low Energy Beacons

    Directory of Open Access Journals (Sweden)

    Yuan Zhuang

    2016-04-01

    Full Text Available Indoor wireless localization using Bluetooth Low Energy (BLE beacons has attracted considerable attention after the release of the BLE protocol. In this paper, we propose an algorithm that uses the combination of channel-separate polynomial regression model (PRM, channel-separate fingerprinting (FP, outlier detection and extended Kalman filtering (EKF for smartphone-based indoor localization with BLE beacons. The proposed algorithm uses FP and PRM to estimate the target’s location and the distances between the target and BLE beacons respectively. We compare the performance of distance estimation that uses separate PRM for three advertisement channels (i.e., the separate strategy with that use an aggregate PRM generated through the combination of information from all channels (i.e., the aggregate strategy. The performance of FP-based location estimation results of the separate strategy and the aggregate strategy are also compared. It was found that the separate strategy can provide higher accuracy; thus, it is preferred to adopt PRM and FP for each BLE advertisement channel separately. Furthermore, to enhance the robustness of the algorithm, a two-level outlier detection mechanism is designed. Distance and location estimates obtained from PRM and FP are passed to the first outlier detection to generate improved distance estimates for the EKF. After the EKF process, the second outlier detection algorithm based on statistical testing is further performed to remove the outliers. The proposed algorithm was evaluated by various field experiments. Results show that the proposed algorithm achieved the accuracy of <2.56 m at 90% of the time with dense deployment of BLE beacons (1 beacon per 9 m, which performs 35.82% better than <3.99 m from the Propagation Model (PM + EKF algorithm and 15.77% more accurate than <3.04 m from the FP + EKF algorithm. With sparse deployment (1 beacon per 18 m, the proposed algorithm achieves the accuracies of <3.88 m at

  6. Beyond the EPBD: The low energy residential settlement Borgo Solare

    International Nuclear Information System (INIS)

    Aste, Niccolo; Adhikari, R.S.; Buzzetti, Michela

    2010-01-01

    and technologies the higher initial embodied energy in a low energy building could quickly paid back during its life span. The economic analysis, in the same way, evidences that higher initial investment in case of energy efficient building could become economically convenient during the life span of the building. This kind of analysis is essential to determine the actual sustainability of a building.

  7. Identification and tracking of low energy spectator protons

    International Nuclear Information System (INIS)

    Mussgiller, A.

    2007-01-01

    The present theses discusses the development, technical design and realization as well as the read-out electronics of a detection system for the identification and tracking of low energy spectator protons. With the knowledge of the four-momentum of such spectator protons it will be possible to use deuterium as an effective neutron target. Previous measurements with an early version of the detection system have already shown that this method works quite well to investigate for instance the ω or η-meson production in proton-neutron collisions. Moreover, after the completion and installation of the polarized internal target (PIT) at ANKE, it will be even possible to engage in that field with double polarized experiments. To increase the luminosity the polarized target is equipped with an extended target cell. The described detection-system will provide the vertex reconstruction for this extended interaction region. In addition, it will act as an independent beam polarimeter at ANKE. The detection system consists of three layers of double-sided silicon strip detectors which are arranged in a telescope structure and placed inside the accelerator vacuum as close as 2 cm to the interaction region. The modular design of the electronics and the support structures for the detectors allows one to exchange detectors and electronics in a maximum flexible way. In a minimum configuration the telescope is equipped with two detectors, a thin (∼ 69 μm) double-sided Silicon strip detector as a first layer and a very thick (≥ 5 mm) double-sided micro-structured Lithium-drifted Silicon detector as a second layer. With this arrangement it is possible to track and identify protons in a kinetic energy range from 2.5 MeV to 25 MeV. For deuterons this range for such a telescope configuration is from 4 MeV to 34 MeV. The performance concerning the energy determination and tracking is shown based on data taken during a beam-time in November of 2003. With the existing setup an energy

  8. Low energy implantation of boron with decaborane ions

    Science.gov (United States)

    Albano, Maria Angela

    The goal of this dissertation was to determine the feasibility of a novel approach to forming ultra shallow p-type junctions (tens of nm) needed for future generations of Si MOS devices. In the new approach, B dopant atoms are implanted by cluster ions obtained by ionization of decaborane (B 10H14) vapor. An experimental ion implanter with an electron impact ion source and magnetic mass separation was built at the Ion Beam and Thin Film Research Laboratory at NJIT. Beams of B10Hx+ ions with currents of a few microamperes and energies of 1 to 12 keV were obtained and used for implantation experiments. Profiles of B and H atoms implanted in Si were measured by Secondary Ion Mass Spectroscopy (SIMS) before and after rapid thermal annealing (RTA). From the profiles, the junction depth of 57 nm (at 1018 cm-3 B concentration) was obtained with 12 keV decaborane ions followed by RTA. The dose of B atoms that can be implanted at low energy into Si is limited by sputtering as the ion beam sputters both the matrix and the implanted atoms. As the number of sputtered B atoms increases with the implanted dose and approaches the number of the implanted atoms, equilibrium of B in Si is established. This effect was investigated by comparison of the B dose calculated from the ion beam integration with B content in the sample measured by Nuclear Reaction Analysis (NRA). Maximum (equilibrium) doses of 1.35 x 1016 B cm -2 and 2.67 x 1016 B cm-2 were obtained at the beam energies of 5 and 12 keV, respectively. The problem of forming shallow p-type junctions in Si is related not only to implantation depth, but also to transient enhanced diffusion (TED). TED in Si implanted with B10Hx+ was measured on boron doping superlattice (B-DSL) marker layers. It was found that TED, following decaborane implantation, is the same as with monomer B+ ion implantation of equivalent energy and that it decreases with the decreasing ion energy. (Abstract shortened by UMI.)

  9. Multi-step direct reactions at low energies

    International Nuclear Information System (INIS)

    Marcinkowski, A.; Marianski, B.

    2001-01-01

    Full text: The theory of the multistep direct (MSD) reactions of Feshbach, Kerman and Koonin has for quite some time become a subject of controversy due to the bi orthogonal distorted waves involved in the transition amplitudes describing the MSD cross sections. The bi orthogonal wave functions result in non-normal DWBA matrix elements, that can be expressed in terms of normal DWBA matrix elements multiplied by the inverse elastic scattering S-matrix. It has been argued that the enhancing inverse S-factors are washed out by averaging over energy in the continuum. As a result normal DWBA matrix elements are commonly used in practical calculations. Almost all analyses of inelastic scattering and charge-exchange reactions using the DWBA matrix elements have concluded that nucleon emission at low energies can be described as one-step reaction mainly. On the other hand, it has been shown that the limits imposed by the energy weighted sum rules (EWSR's) on transition of given angular momentum transfer lead to a significant reduction of the one step cross section that can be compensated by the enhanced MSD cross sections obtained with the use of the non-normal DWBA matrix elements. Very recently the MSD theory of FKK was modified to include collective excitations and the non-normal DWBA matrix elements and the prescription for calculations of the cross sections for the MSD reactions was given. In the present paper we present the results of the modified theory used for describing the 93 Nb (n,xn) 93 Nb reaction at incident energy of 20 MeV and the 65 Cu (p,xn) 65 Zn reaction at 27 MeV. The results show enhanced contributions from two-, three- and four step reactions. We investigate the importance of the multi-phonon, multi particle hole and the mixed particle hole-phonon excitations in neutron scattering to the continuum. We also show the importance of the different sequences of collisions of the leading continuum nucleon that contribute to the MSD (p,n) reaction. When all

  10. Deep influence of passive low energy consumption multi-storey residential building in cold region

    Science.gov (United States)

    Shuai, Zhang; Lihua, Zhao; Rong, Jin; Dong, Junyan

    2018-02-01

    The example of passive architecture demonstration building in Jilin Province, China, based on the practical experience of this project, the control index of passive and low energy consumption residential buildings in cold and passive buildings is referenced by reference to the German construction standard and the Chinese residence construction document, “passive ultra-low energy consumption green Building Technology Guide (Trial)”. The requirement of passive low energy residential buildings on the ground heat transfer coefficient limits is determined, and the performance requirements of passive residential buildings are discussed. This paper analyzes the requirement of the passive low energy residential building on the ground heat transfer coefficient limit, and probes into the influence factors of the ground thermal insulation of the passive low energy consumption residential building. The construction method of passive low energy consumption residential building is proposed.

  11. The Marshall Space Flight Center Low-Energy Ion Facility: a preliminary report

    International Nuclear Information System (INIS)

    Biddle, A.P.; Reynolds, J.W.; Chisholm, W.L. Jr.; Hunt, R.D.

    1983-10-01

    The Low-Energy Ion Facility (LEIF) is designed for laboratory research of low-energy ion beams similar to those present in the magnetosphere. In addition, it provides the ability to develop and calibrate low-energy, less than 50 eV, plasma instrumentation over its full range of energy, mass, flux, and arrival angle. The current status of this evolving resource is described. It also provides necessary information to allow users to utilize it most efficiently

  12. Influence of low-energy scattering on loosely bound states

    International Nuclear Information System (INIS)

    Sparenberg, Jean-Marc; Capel, Pierre; Baye, Daniel

    2010-01-01

    Compact algebraic equations are derived that connect the binding energy and the asymptotic normalization constant (ANC) of a subthreshold bound state with the effective-range expansion of the corresponding partial wave. These relations are established for positively charged and neutral particles, using the analytic continuation of the scattering (S) matrix in the complex wave-number plane. Their accuracy is checked on simple local potential models for the 16 O+n, 16 O+p, and 12 C+α nuclear systems, with exotic nuclei and nuclear astrophysics applications in mind.

  13. Milagro: A low energy threshold extensive air shower array

    Energy Technology Data Exchange (ETDEWEB)

    Sinnis, C.

    1994-12-31

    Observations of high-energy gamma rays from astronomical sources have revolutionized our view of the cosmos. Gamma rays with energies up to {approximately}10 GeV can be observed directly with space-based instruments. Above 100 GeV the low flux of gamma rays requires one to utilize ground-based instruments. Milagro is a new type of gamma-ray detector based on water Cerenkov technology. This new design will enable to continuously observe the entire overhead sky, and be sensitive to cosmic rays with energies above {approximately}250 GeV. These attributes make Milagro an ideal detector for the study of high-energy transient phenomenon.

  14. Low energy neutrino astronomy with the large liquid-scintillation detector LENA

    International Nuclear Information System (INIS)

    Undagoitia, T Marrodan; Feilitzsch, F von; Goeger-Neff, M; Hochmuth, K A; Oberauer, L; Potzel, W; Wurm, M

    2006-01-01

    The detection of low energy neutrinos in a large liquid scintillation detector may provide further important information on astrophysical processes as supernova physics, solar physics and elementary particle physics as well as geophysics. In this contribution, a new project for Low Energy Neutrino Astronomy (LENA) consisting of a 50 kt scintillation detector is presented

  15. Simulation to support passive and low energy cooling system design in the Czech Republic

    NARCIS (Netherlands)

    Lain, M.; Bartak, M.; Drkal, F.; Hensen, J.L.M.

    2005-01-01

    This paper deals with the passive and low energy cooling technologies in the Czech Republic. The role of computer simulation in low energy building design and optimization is discussed. The work includes buildings and systems analysis as well as climate analysis in order to estimate the potential of

  16. Calculations for very low energy scattering of positrons by molecular hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J.N. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)], E-mail: james.cooper@maths.nottingham.ac.uk; Armour, E.A.G. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2008-02-15

    We give a progress report on ongoing calculations of phase shifts for very low energy elastic scattering of positrons by molecular hydrogen, using the generalised Kohn variational method. Further, provisional calculations of Z{sub eff} for molecular hydrogen at low energies are presented and discussed. The preliminary nature of the work is emphasised throughout.

  17. Air Tightness and Energy Performance of an Arctic Low-Energy House

    DEFF Research Database (Denmark)

    Rode, Carsten; Vladyková, Petra; Kotol, Martin

    2010-01-01

    A low-energy house has been built in Sisimiut, Greenland, five years ago. An ambitious target was set for its low energy consumption for heating: 80 kWh/(m2∙a). But unfortunately, the house has used more energy than planned, approximately 140 kWh/(m2∙a). Although higher than anticipated, this is ...

  18. Solar X-ray Spectrometer (SOXS) Mission – Low Energy Payload

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We present the first results from the 'Low Energy Detector' payload of 'Solar X-ray Spectrometer (SOXS)' mission, which was launched onboard GSAT-2 Indian spacecraft on 08 May 2003 by GSLV-D2 rocket to study the solar flares. The SOXS Low Energy Detector (SLD) payload was designed, developed ...

  19. Determination of low-energy constants of Wilson chiral perturbation theory

    International Nuclear Information System (INIS)

    Herdoiza, Gregorio; Univ. Autonoma de Madrid, Contoblanco; Univ. Autonoma de Madrid; Jansen, Karl; Univ. Cyprus, Nicosia; Michael, Chris; Ottnad, Konstantin; Urbach, Carsten; Univ. Bonn

    2013-03-01

    By matching Wilson twisted mass lattice QCD determinations of pseudoscalar meson masses to Wilson Chiral Perturbation Theory we determine the low-energy constants W 6 ' , W 8 ' and their linear combination c 2 . We explore the dependence of these low-energy constants on the choice of the lattice action and on the number of dynamical flavours.

  20. Performance of low-temperature district heating for low-energy houses

    DEFF Research Database (Denmark)

    Brand, Marek; Dalla Rosa, Alessandro; Svendsen, Svend

    2010-01-01

    A Low Energy District Heating (LEDH) network supplying district heating water with temperature 50°C was built in Lærkehaven-Lystrup, Denmark, as a part of the ongoing “Energy Technology Development and Demonstration Programme” [EUDP, 2008] focused on “CO2-reduction in low energy buildings and com...

  1. MicroBooNE: The Search For The MiniBooNE Low Energy Excess

    Energy Technology Data Exchange (ETDEWEB)

    Kaleko, David [Columbia Univ., New York, NY (United States)

    2017-01-01

    This thesis describes work towards the search for a low energy excess in MicroBooNE. What MicroBooNE is, what the low energy excess is, and how one searches for the latter in the former will be described in detail.

  2. Excitation and dissociation of molecules by low-energy (0-15 eV) electrons

    International Nuclear Information System (INIS)

    Verhaart, G.J.

    1980-01-01

    The author deals with excitation and dissociation processes which result from the interaction between low-energy (0.15 eV) electrons and molecules. Low-energy electron-impact spectroscopy is used to gain a better knowledge of the electronic structure of halomethanes, ethylene and some of its halogen substituted derivatives, and some more complex organic molecules. (Auth.)

  3. Perceptional and socio-economic factors in adoption of low energy houses

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Krushna; Nair, Gireesh; Gustavsson, Leif [Ecotechnology, Mid Sweden Univ., Oestersund (Sweden)

    2009-07-01

    Diffusion of low energy houses reduces greenhouse emission from residential sector. However, adoption of such houses depends on the perception of the potential buyers. In this paper we have analyzed Swedish homeowners' perception of low energy houses. Data was collected in 2008 from a mail-in questionnaire survey of about 3000 owners of detached houses. Results showed that about 39% of respondents, especially young, educated or whose household income was high, would consider buying a low energy house. Majority of the respondents agreed that a low energy house in comparison to a conventional house has lower operating energy cost, but higher investment cost. Majority thought that low energy houses do not have lower resale value, lower aesthetic appearance, or greater operational difficulty

  4. A topological screening heuristic for low-energy, high-index surfaces

    Science.gov (United States)

    Sun, Wenhao; Ceder, Gerbrand

    2018-03-01

    Robust ab initio investigations of nanoparticle surface properties require a method to identify candidate low-energy surface facets a priori. By assuming that low-energy surfaces are planes with high atomic density, we devise an efficient algorithm to screen for low-energy surface orientations, even if they have high (hkl) miller indices. We successfully predict the observed low-energy, high-index { 10 12 bar } and { 10 1 bar 4 } surfaces of hematite α-Fe2O3, the {311} surfaces of cuprite Cu2O, and the {112} surfaces of anatase TiO2. We further tabulate candidate low-energy surface orientations for nine of the most common binary oxide structures. Screened surfaces are found to be generally applicable across isostructural compounds with varying chemistries, although relative surface energies between facets may vary based on the preferred coordination of the surface atoms.

  5. Hard x-ray to low energy gamma ray spectrum of the Crab Nebula

    International Nuclear Information System (INIS)

    Jung, G.V.

    1986-01-01

    The spectrum of the Crab Nebula has been determined in the energy range 10 keV to 5 MeV from the data of the UCSD/MIT Hard-X-ray and Low Energy Gamma Ray Experiment on the first High Energy Astronomy Observatory, HEAO-1. The x-ray to γ-ray portion of the continuous emission from the Crab is indicative of the electron spectrum, its transport through the nebula, and the physical conditions near the shocked interface between the nebular region and the wind which is the physical link between the nebula and the pulsar, NP0532. The power-law dependence of the spectrum found in the lower-energy decade of this observation (10 to 100 keV) is not continued without modification to higher energies. Evidence for this has been accumulating from previous observations in the γ-ray ranges of 1-10 MeV and above 35 MeV. The observations on which this dissertation is based further characterize the spectral change in the 100 keV to 1 MeV region. These observations provide a crucial connection between the x-ray and γ-ray spectrum of the non-pulsed emission of the Crab Nebula. The continuity of this spectrum suggests that the emission mechanism responsible for the non-pulsed γ-rays observed above 35 MeV is of the same origin as the emission at lower energies, i.e. that of synchrotron radiation in the magnetic field of the nebula

  6. Studies of nuclear reaction at very low energies

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1992-01-01

    The deuteron radiative capture reactions on 2 H, 6 Li and 10 B have been measured between center of mass energies of 20 and 140 keV. Of note is the observation that the gamma ray-to-charged particle branching ratio for the DD reaction appears independent of energy down to a center of mass energy of 20 keV, consistent with some and contrary to other theoretical models. We have investigated the ratio of the reactions D(d,p)T and D(d,n) 3 He down to c.m. energies of 3 keV and the ratio of the reactions 6Li(d,p) 7 Li and 6 LI(d,α) 4 He down to a c.m. energy of 19 keV. The DD reaction ratio is independent of energy while the (d,p) branch of the D- 6 Li evinces a significant enhancement at the lowest measured energies. We have continued our investigation of charged particle production from deuterium-metal systems at a modest level of activity. Noteworthy in this investigation is the observation of 3 MeV protons from deuteron beam loaded Ti and LiD targets subjected to extreme thermal disequilibria. Significant facility improvements were realized during the most recent contract period. Specifically the downstream magnetic analysis system proposed to eliminate beam induced contaminants has been installed and thoroughly tested. This improvement should allow the D(a,γ) 6 Li reaction to be measured in the coming contract period. A scattering chamber required for the measurement of the 7 Li( 3 He,p) 9 Be reaction has been designed, fabricated and installed on the accelerator. A CAMAC based charged particle identification system has been assembled also for use in our proposed measurement of the 7 Li( 3 He, p) 9 Be

  7. Low-energy excitations in amorphous films of silicon and germanium

    International Nuclear Information System (INIS)

    Liu, X.; Pohl, R.O.

    1998-01-01

    We present measurements of internal friction and shear modulus of amorphous Si (a-Si) and amorphous Ge (a-Ge) films on double-paddle oscillators at 5500 Hz from 0.5 K up to room temperature. The temperature- independent plateau in internal friction below 10 K, which is common to all amorphous solids, also exists in these films. However, its magnitude is smaller than found for all other amorphous solids studied to date. Furthermore, it depends critically on the deposition methods. For a-Si films, it decreases in the sequence of electron-beam evaporation, sputtering, self-ion implantation, and hot-wire chemical-vapor deposition (HWCVD). Annealing can also reduce the internal friction of the amorphous films considerably. Hydrogenated a-Si with 1 at.% H prepared by HWCVD leads to an internal friction more than two orders of magnitude smaller than observed for all other amorphous solids. The internal friction increases after the hydrogen is removed by effusion. Our results are compared with earlier measurements on a-Si and a-Ge films, none of which had the sensitivity achieved here. The variability of the low-energy tunneling states in the a-Si and a-Ge films may be a consequence of the tetrahedrally bonded covalent continuous random network. The perfection of this network, however, depends critically on the preparation conditions, with hydrogen incorporation playing a particularly important role. copyright 1998 The American Physical Society

  8. Green infrastructure and low energy architecture for eco-tourism in Asinara island

    Science.gov (United States)

    Trombadore, Antonella; Rolovic, Dusan; Congiatu, Pier Paolo

    2018-05-01

    The paper will present the sustainable and low energy architecture approach that has been developed for a small island in Sardinia, Italy. The island has hosted several prison complexes in the past two centuries, now converted into a National Park, since its creation as a national park its architectural and urban patrimony have been completely abandoned. Its few built-up areas and/or urban developments do have an enormous potential, but past administrations failed in the attempt to offer a commercially attractive model. The project focuses mainly on the development of a Strategic Plan for the regeneration of the island: the main goal is to create completely new activities and functions which are both compatible with its touristic potential and especially with the natural fragility of the ecosystem. These functions have been planned in order to give life and continuous activity to the island, but with extreme care towards its cohesion with the environment and the biodiversity. Results consist in various minor agricultural activities that have been reinstated based on the past activities, and different touristic functions focused on a specific and Eco-responsible market niche. These activities are supported by a complex network of structures and services dedicated to maintaining the balance of the ecosystem intact, while this increases the quality of its offer, thus allowing the creation of a model of sustainable management of natural resources and commercial exploitation without risk for the environment.

  9. Insights into reactive scattering of Pu + H2 at low energies

    Science.gov (United States)

    Gao, Cong-Zhang; Wu, Yong; Liu, Ling; Wang, Pei; Wang, Jian-Guo

    2017-08-01

    The corrosion of metal interfaces, due to continuous exposure to gaseous hydrogen atmosphere, significantly limits the applications of plutonium-based nuclear materials in the related fields. In this work, we simplify the situations by considering the fundamental reactions of Pu atom with a single H2 molecule, and investigate from a theoretical perspective collision dynamics of Pu + H2 at low energies (0.2 \\text{eV}\\text{--}13 \\text{eV}) based on ab initio potential energy surfaces. Trajectory calculation analysis shows that three main channels, the formation of the PuH2, the PuH fragment, and the fragmentation, exhibit different energy-dependent cross sections, from which we observed that the PuH2 formation is non-threshold reaction, whereas the other two channels are featured by pronounced threshold effects, which is in consistent with experimental observations. In addition, we find that three-body effects can play a decisive role in the reactions since the simplified Morse potential energy surfaces can even yield spurious results in some situations.

  10. Design study of low-energy beam transport for multi-charge beams at RAON

    Science.gov (United States)

    Bahng, Jungbae; Qiang, Ji; Kim, Eun-San

    2015-12-01

    The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

  11. Design study of low-energy beam transport for multi-charge beams at RAON

    Energy Technology Data Exchange (ETDEWEB)

    Bahng, Jungbae [Department of Physics, Kyungpook National University, Daegu 41566 (Korea, Republic of); Qiang, Ji [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kim, Eun-San, E-mail: eskim1@korea.ac.kr [Department of Accelerator Science, Graduate School, Korea University Sejong Campus, Sejong 30019 (Korea, Republic of)

    2015-12-21

    The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-energy beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-energy beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial beam energy of 10 keV/u. After extraction, the ion beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the beam dynamics of the LEBT system.

  12. Radiation damage in urania crystals implanted with low-energy ions

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tien Hien, E-mail: tien-hien.nguyen@u-psud.fr [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM – UMR 8609), CNRS-IN2P3-Université Paris-Sud, Bâtiments 104-108, 91405 Orsay Campus (France); Garrido, Frédérico; Debelle, Aurélien; Mylonas, Stamatis [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM – UMR 8609), CNRS-IN2P3-Université Paris-Sud, Bâtiments 104-108, 91405 Orsay Campus (France); Nowicki, Lech [The Andrzej Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Thomé, Lionel; Bourçois, Jérôme; Moeyaert, Jérémy [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM – UMR 8609), CNRS-IN2P3-Université Paris-Sud, Bâtiments 104-108, 91405 Orsay Campus (France)

    2014-05-01

    Implantations with low-energy ions (470-keV Xe and 500-keV La with corresponding ion range Rp ∼ 85 nm and range straggling ΔRp ∼ 40 nm) have been performed to investigate both radiation and chemical effects due to the incorporation of different species in UO{sub 2} (urania) crystals. The presence of defects was monitored in situ after each implantation fluence step by the RBS/C technique. Channelling data were analysed afterwards by Monte-Carlo simulations with a model of defects involving (i) randomly displaced atoms (RDA) and (ii) distorted rows, i.e. bent channels (BC). While increasing the ion fluence, the accumulation of RDA leads to a steep increase of the defect fraction in the range from 4 to 7 dpa regardless of the nature of bombarding ions followed by a saturation plateau over a large dpa range. A clear difference of 6% in the yield of saturation plateaus between irradiation with Xe and La ions was observed. Conversely, the evolutions of the fraction of BC showed a similar regular increase with increasing ion fluence for both ions. Moreover, this increase is shifted to a larger fluence in comparison to the sharp increase step of RDA. This phenomenon indicates a continuous structural modification of UO{sub 2} crystals under irradiation unseen by the measurement of RDA.

  13. Extraction design and low energy beam transport optimization of space charge dominated multispecies ion beam sources

    International Nuclear Information System (INIS)

    Delferriere, O.; De Menezes, D.

    2004-01-01

    In all accelerator projects, the low energy part of the accelerator has to be carefully optimized to match the beam characteristic requirements of the higher energy parts. Since 1994 with the beginning of the Injector of Protons for High Intensity (IPHI) project and Source of Light Ions with High Intensities (SILHI) electron cyclotron resonance (ECR) ion source development at CEA/Saclay, we are using a set of two-dimensional (2D) codes for extraction system optimization (AXCEL, OPERA-2D) and beam transport (MULTIPART). The 95 keV SILHI extraction system optimization has largely increased the extracted current, and improved the beam line transmission. From these good results, a 130 mA D + extraction system for the International Fusion Material Irradiation Facility project has been designed in the same way as SILHI one. We are also now involved in the SPIRAL 2 project for the building of a 40 keV D + ECR ion source, continuously tunable from 0.1 to 5 mA, for which a special four-electrode extraction system has been studied. In this article we will describe the 2D design process and present the different extraction geometries and beam characteristics. Simulation results of SILHI H + beam emittance will be compared with experimental measurements

  14. Study on garbage disposal mode with low energy consumption for villages and towns in cold region

    Directory of Open Access Journals (Sweden)

    Ma Yi

    2016-01-01

    Full Text Available Through field research of typical villages and towns in China's northern cold region, this paper research energy consumption and resource recovery in the process of village and town garbage collection and disposal and organizes current situation and problems of village and town garbage collection and disposal. At present, village and town garbage collection and disposal means and thoughts are traditional and lag behind in China's northern cold region. There is the lack of garbage collection and disposal mode suitable for cold villages and towns. Thus, village and town resources are not effectively utilized, and residents’ living environment is affected continuously. This paper selects two mature garbage disposal methods: sanitary landfill and incineration power generation. Meanwhile, energy consumption and ultimate emission utilization of two schemes in garbage collection and disposal links are overall compared to propose garbage collection and disposal mode with low energy consumption suitable for green villages and towns in cold region. Besides, various control indexes of village and town garbage disposal schemes are explained in detail in combination of specific conditions.

  15. The effective QCD theory at low energy; La theorie effective de QCD a basse energie

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, M. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    1995-12-31

    Quantum chromodynamics is studied here in the range of low energies. The Chiral perturbation theory is presented, this theory is based on a thorough study of QCD symmetry, of general field theory principles and of S-matrices. Ward identities are defined within the scope of current algebras and by using functional method. Their consequences on Chiral structure of QCD emptiness and on strong interaction at low energies are studied. The pion-pion diffusion at low energies is treated as an example. (A.C.) 70 refs.

  16. Can cellulite be treated with low-energy extracorporeal shock wave therapy?

    Science.gov (United States)

    Angehrn, Fiorenzo; Kuhn, Christoph; Voss, Axel

    2007-01-01

    The present study investigates the effects of low-energy defocused extracorporeal generated shock waves on collagen structure of cellulite afflicted skin. Cellulite measurement using high-resolution ultrasound technology was performed before and after low-energy defocused extracorporeal shock wave therapy (ESWT) in 21 female subjects. ESWT was applied onto the skin at the lateral thigh twice a week for a period of six weeks. Results provide evidence that low-energy defocused ESWT caused remodeling of the collagen within the dermis of the tested region. Improving device-parameters and therapy regimes will be essential for future development of a scientific based approach to cellulite treatment. PMID:18225463

  17. Comparison of low-energy versus high-energy biphasic defibrillation shocks following prolonged ventricular fibrillation.

    Science.gov (United States)

    Walcott, Gregory P; Melnick, Sharon B; Killingsworth, Cheryl R; Ideker, Raymond E

    2010-01-01

    Since the initial development of the defibrillator, there has been concern that, while delivery of a large electric shock would stop fibrillation, it would also cause damage to the heart. This concern has been raised again with the development of the biphasic defibrillator. To compare defibrillation efficacy, postshock cardiac function, and troponin I levels following 150-J and 360-J shocks. Nineteen swine were anesthetized with isoflurane and instrumented with pressure catheters in the left ventricle, aorta, and right atrium. The animals were fibrillated for 6 minutes, followed by defibrillation with either low-energy (n = 8) or high-energy (n = 11) shocks. After defibrillation, chest compressions were initiated and continued until return of spontaneous circulation (ROSC). Epinephrine, 0.01 mg/kg every 3 minutes, was given for arterial blood pressure < 50 mmHg. Hemodynamic parameters were recorded for four hours. Transthoracic echocardiography was performed and troponin I levels were measured at baseline and four hours following ventricular fibrillation (VF). Survival rates at four hours were not different between the two groups (low-energy, 5 of 8; high-energy, 7 of 11). Results for arterial blood pressure, positive dP/dt (first derivative of pressure measured over time, a measure of left ventricular contractility), and negative dP/dt at the time of lowest arterial blood pressure (ABP) following ROSC were not different between the two groups (p = not significant [NS]), but were lower than at baseline. All hemodynamic measures returned to baseline by four hours. Ejection fractions, stroke volumes, and cardiac outputs were not different between the two groups at four hours. Troponin I levels at four hours were not different between the two groups (12 +/- 11 ng/mL versus 21 +/- 26 ng/mL, p = NS) but were higher at four hours than at baseline (19 +/- 19 ng/mL versus 0.8 +/- 0.5 ng/mL, p < 0.05, groups combined). Biphasic 360-J shocks do not cause more cardiac damage

  18. The production of radionuclides for nuclear medicine from a compact, low-energy accelerator system.

    Science.gov (United States)

    Webster, William D; Parks, Geoffrey T; Titov, Dmitry; Beasley, Paul

    2014-05-01

    The field of nuclear medicine is reliant on radionuclides for medical imaging procedures and radioimmunotherapy (RIT). The recent shut-downs of key radionuclide producers have highlighted the fragility of the current radionuclide supply network, however. To ensure that nuclear medicine can continue to grow, adding new diagnostic and therapy options to healthcare, novel and reliable production methods are required. Siemens are developing a low-energy, high-current - up to 10 MeV and 1 mA respectively - accelerator. The capability of this low-cost, compact system for radionuclide production, for use in nuclear medicine procedures, has been considered. The production of three medically important radionuclides - (89)Zr, (64)Cu, and (103)Pd - has been considered, via the (89)Y(p,n), (64)Ni(p,n) and (103)Rh(p,n) reactions, respectively. Theoretical cross-sections were generated using TALYS and compared to experimental data available from EXFOR. Stopping power values generated by SRIM have been used, with the TALYS-generated excitation functions, to calculate potential yields and isotopic purity in different irradiation regimes. The TALYS excitation functions were found to have a good agreement with the experimental data available from the EXFOR database. It was found that both (89)Zr and (64)Cu could be produced with high isotopic purity (over 99%), with activity yields suitable for medical diagnostics and therapy, at a proton energy of 10MeV. At 10MeV, the irradiation of (103)Rh produced appreciable quantities of (102)Pd, reducing the isotopic purity. A reduction in beam energy to 9.5MeV increased the radioisotopic purity to 99% with only a small reduction in activity yield. This work demonstrates that the low-energy, compact accelerator system under development by Siemens would be capable of providing sufficient quantities of (89)Zr, (64)Cu, and (103)Pd for use in medical diagnostics and therapy. It is suggested that the system could be used to produce many other

  19. Low energy characterization of Caliste HD, a CdTe based imaging spectrometer

    International Nuclear Information System (INIS)

    Dubos, S.; Limousin, O.; Blondel, C.; Chipaux, R.; Menesguen, Y.; Meuris, A.; Orduna, T.; Tourette, T.; Sauvageon, A.

    2012-01-01

    Caliste HD is a recently developed micro-camera designed for X and gamma-rays astronomy, based on a 1*1 cm 2 CdTe Schottky pixelated detector. Its entire surface is composed of 256 pixels, disposed on a 16*16 pixels matrix with 625 micrometers pitch. This spectrometer is buttable on its 4 sides and can be used to create a large focal plane. Caliste HD is designed for space environment and its front-end electronic has a low power consumption and excellent noise performances which can provide an extended dynamic range, from 2 keV to 1 MeV as well as excellent energy resolutions. This large spectroscopic window is suited to observe astrophysical sources for a wide range of wavelengths. Moreover, electronic noise performances of this instrument were designed to set the low level-threshold lower than 2 keV; these continuous improvements now allow studying detailed spectroscopic performances at very low energies. For this purpose, we have exposed the Caliste HD module to a mono-energetic X-rays beam, and set energies between 2 and 12 keV emphasizing the 2 to 6 keV band. We could measure accurately detections efficiencies for the lowest energies and found it to be from 43% to 75% at 2.1 keV and 11.6 keV respectively, considering only particles detected in photopeak for single events, ignoring events impinging between two adjacent pixels. Absorption edges due to the Platinum (Pt) entrance electrode have been detected, as well as other characteristics absorption edges on the efficiency curve caused by Cd and Te elements. This efficiency detection profile thereby highlights crucial effects of the Pt electrode opacity on Caliste HD low energy response, and suggests the presence of absorption zones at the interface between CdTe crystal and Platinum. Besides, using a mono-energetic beam allows fine energy resolution measurement. It has been found to be ranging from 560 and 760 eV FWHM between 2 and 12 keV. In the same way, another crucial parameter - the linearity of the

  20. Before the Ring: synthesis of linear organic molecules in astrophysical ices by low energy electron impact

    Science.gov (United States)

    Huels, Michael A.; Bass Andrew, D.; Mirsaleh-Kohan, Nasrin; Sanche, Leon

    The question of the origin for the building blocks of life, either synthesized here on earth, or in space [1], has been the subject of much debate, experimental investigation, or astronomical observation, much of it stimulated by the early experiments of Miller [2], and subsequent space radiation related variations thereof [3-5]. And while the precise details of the formation of even the simplest biomolecules that make up life on earth still remain shrouded inmystery, one of the notions that persist throughout the debate is that the building blocks of life, such as amino-acids, or even the cyclic components of RNA and DNA, or other cyclic hydrocarbons (e.g. PHAs), where synthesized via radiolysis [6] either in the earths proto-atmosphere, its early oceans, or in the near interstellar space surrounding the early earth. Here we provide experimental evidence for the hypothesis that interactions of low energy secondary electrons and ions, formed during the radiolysis of matter, with atoms and molecules in the medium, may have played, and may still play an important role in the chemical transformation of astrophysical or planetary surface ices [7], where they lead to the synthesis of more complex chemical species from less complex, naturally occurring components. We report the synthesis and desorption of new chemical species from simple molecular surface ices, containing CH4 / CD4 , C2 D2 , O2 , CO, CO2 , or N2 in various combination mixtures, irradiated by low energy (CO+ (n = 1-3), among others. The formation of all these linear, pre-biotic molecular species, produced here by electron initiated cation-reactions in simple molecular films, suggests that similar mechanisms likely precede the synthesis of life's most basic cyclic molecular components in planetary, or astrophysical surface ices that are continuously subjected to the types of space radiations (UV, X-or -ray, or heavy ions) that can generate such low energy secondary electrons. [Funded by NSERC and Canadian