Sample records for axion power international

  1. Axion Power International Inc formerly Tamboril | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovation in Carbon CaptureAtria PowerAxeon Technology Ltd Jump

  2. The International Axion Observatory (IAXO)

    E-Print Network [OSTI]

    I. G. Irastorza; F. T. Avignone; G. Cantatore; S. Caspi; J. M. Carmona; T. Dafni; M. Davenport; A. Dudarev; G. Fanourakis; E. Ferrer-Ribas; J. Galan; J. A. Garcia; T. Geralis; I. Giomataris; S. Gninenko; H. Gomez; D. H. H. Hoffmann; F. J. Iguaz; K. Jakovcic; M. Krcmar; B. Lakic; G. Luzon; A. Lindner; M. Pivovaroff; T. Papaevangelou; G. Raffelt; J. Redondo; A. Rodr?guez; S. Russenschuck; J. Ruz; I. Shilon; H. Ten Kate; A. Tomas; S. Troitsky; K. van Bibber; J. A. Villar; J. Vogel; L. Walckiers; K. Zioutas

    2012-01-18T23:59:59.000Z

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of a few 10$^{12}$ GeV$^{-1}$, i.e. 1 - 1.5 orders of magnitude beyond the one currently achieved by CAST. The project relies on improvements in magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include the detection of electron-coupled axions invoked to solve the white dwarfs anomaly, relic axions, and a large variety of more generic axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics. This contribution is a summary of our paper [1] to which we refer for further details.

  3. Conceptual Design of the International Axion Observatory (IAXO)

    E-Print Network [OSTI]

    Armengaud, E; Betz, M; Brax, P; Brun, P; Cantatore, G; Carmona, J M; Carosi, G P; Caspers, F; Caspi, S; Cetin, S A; Chelouche, D; Christensen, F E; Dael, A; Dafni, T; Davenport, M; Derbin, A V; Desch, K; Diago, A; Döbrich, B; Dratchnev, I; Dudarev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Galán, J; García, J A; Garza, J G; Geralis, T; Gimeno, B; Giomataris, I; Gninenko, S; Gómez, H; González-Díaz, D; Guendelman, E; Hailey, C J; Hiramatsu, T; Hoffmann, D H H; Horns, D; Iguaz, F J; Irastorza, I G; Isern, J; Imai, K; Jakobsen, A C; Jaeckel, J; Jakov?i?, K; Kaminski, J; Kawasaki, M; Karuza, M; Kr?mar, M; Kousouris, K; Krieger, C; Laki?, B; Limousin, O; Lindner, A; Liolios, A; Luzón, G; Matsuki, S; Muratova, V N; Nones, C; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Ringwald, A; Russenschuck, S; Ruz, J; Saikawa, K; Savvidis, I; Sekiguchi, T; Semertzidis, Y K; Shilon, I; Sikivie, P; Silva, H; Kate, H ten; Tomas, A; Troitsky, S; Vafeiadis, T; Bibber, K van; Vedrine, P; Villar, J A; Vogel, J K; Walckiers, L; Weltman, A; Wester, W; Yildiz, S C; Zioutas, K

    2014-01-01T23:59:59.000Z

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few $\\times 10^{-12}$ GeV$^{-1}$ and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling $g_{ae}$ with sensitivity $-$for the first time$-$ to values of $g_{ae}$ not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, w...

  4. New superconducting toroidal magnet system for IAXO, the international AXion observatory

    SciTech Connect (OSTI)

    Shilon, I.; Dudarev, A.; Silva, H.; Wagner, U.; Kate, H. H. J. ten [European Organization for Nuclear Research (CERN), CH-1211, Genève 23 (Switzerland)

    2014-01-29T23:59:59.000Z

    Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored energy of 500 MJ. The magnetic field optimization process to arrive at maximum detector yield is described. In addition, materials selection and their structure and sizing has been determined by force and stress calculations. Thermal loads are estimated to size the necessary cryogenic power and the concept of a forced flow supercritical helium based cryogenic system is given. A quench simulation confirmed the quench protection scheme.

  5. Axion Cosmology

    E-Print Network [OSTI]

    Pierre Sikivie

    2006-11-10T23:59:59.000Z

    Outline: 1. Thermal axions 2. Axion field evolution 3. The domain wall problem 4. Cold axions 5. Axion miniclusters 6. Axion isocurvature perturbations

  6. Search of Axions from a Nuclear Power Reactor with a High-Purity Germanium Detector

    E-Print Network [OSTI]

    H. M. Chang; TEXONO Collaboration

    2007-01-21T23:59:59.000Z

    A search of axions produced in nuclear transitions was performed at the Kuo-Sheng Nuclear Power Station with a high-purity germanium detector of mass 1.06 kg at a distance of 28 m from the 2.9 GW reactor core. The expected experimental signatures were mono-energetic lines produced by their Primakoff or Compton conversions at the detector. Based on 459.0/96.3 days of Reactor ON/OFF data, no evidence of axion emissions were observed and constraints on the couplings $\\gagg$ and $\\gaee$ versus axion mass $m_a$ within the framework of invisible axion models were placed. The KSVZ and DFSZ models can be excluded for 10^4 eV < m_a < 10^6 ~eV. Model-independent constraints on \\gagg \\gv1 < 7.7 X 10^{-9} GeV^{-2} for m_{a} < 10^5 eV and \\gaee \\gv1 < 1.3 X 10^{-10} for m_{a} < 10^6 eV at 90% confidence level were derived. This experimental approach provides a unique probe for axion mass at the keV--MeV range not accessible to the other techniques.

  7. Axion beams at HERA?

    E-Print Network [OSTI]

    K. Piotrzkowski

    2007-01-09T23:59:59.000Z

    If the recently observed anomaly in the PVLAS experiment is due to the axion, then the powerful beams of synchrotron photons, propagating through high magnetic field of the HERA beamline, become strong axion sources. This gives a unique opportunity of detection of the axion-photon interactions by installing a small detector in the HERA tunnel, and to corroborate the axion hypothesis within a few days of running.

  8. International Power Engineering Research Collaborations

    E-Print Network [OSTI]

    Gross, George

    , Power Systems, International Cooperation, Power Engineering Education, Industry and Government Support of electricity is on the rise as efficient and environmentally sensitive electricity services are key have major impacts on the topics of research projects and the education of the new generation of power

  9. Sandia National Laboratories: Solar Power International

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Power International Sandia to host PV Bankability workshop at Solar Power International (SPI) 2013 On September 24, 2013, in Conferences, Energy, Events, News & Events,...

  10. Transplanckian axions !?

    E-Print Network [OSTI]

    Miguel Montero; Angel M. Uranga; Irene Valenzuela

    2015-04-15T23:59:59.000Z

    We discuss quantum gravitational effects in Einstein theory coupled to periodic axion scalars to analyze the viability of several proposals to achieve superplanckian axion periods (aka decay constants) and their possible application to large field inflation models. The effects we study correspond to the nucleation of euclidean gravitational instantons charged under the axion, and our results are essentially compatible with (but independent of) the Weak Gravity Conjecture, as follows: Single axion theories with superplanckian periods contain gravitational instantons inducing sizable higher harmonics in the axion potential, which spoil superplanckian inflaton field range. A similar result holds for multi-axion models with lattice alignment (like the Kim-Nilles-Peloso model). Finally, theories with $N$ axions can still achieve a moderately superplanckian periodicity (by a $\\sqrt{N}$ factor) with no higher harmonics in the axion potential. The Weak Gravity Conjecture fails to hold in this case due to the absence of some instantons, which are forbidden by a discrete $\\mathbf{Z}_N$ gauge symmetry. Finally we discuss the realization of these instantons as euclidean D-branes in string compactifications.

  11. Axion alternatives

    E-Print Network [OSTI]

    I. Antoniadis; A. Boyarsky; Oleg Ruchayskiy

    2006-06-29T23:59:59.000Z

    If recent results of the PVLAS collaboration proved to be correct, some alternative to the traditional axion models are needed. We present one of the simplest possible modifications of axion paradigm, which explains the results of PVLAS experiment, while avoiding all the astrophysical and cosmological restrictions. We also mention other possible models that possess similar effects.

  12. Axions 05

    E-Print Network [OSTI]

    Pierre Sikivie

    2005-10-02T23:59:59.000Z

    The Strong CP Problem and its resolution through the existence of an axion are briefly reviewed. The combined constraints from accelerator searches, the evolution of red giants and the duration of the SN 1987a neutrino pulse require the axion mass $m_a$ to be less than $3 \\cdot 10^{-3}$ eV. On the other hand, the requirement that the axion does not overclose the universe implies a lower bound on $m_a$ of order $10^{-6}$ eV. This lower bound can, however, be relaxed in a number of ways. If $m_a$ is near the lower bound, axions are an important contribution to the energy density of the universe in the form of (very) cold dark matter. Dark matter axions can be searched for on Earth by stimulating their conversion to microwave photons in an electromagnetic cavity permeated by a magnetic field. Using this technique, limits on the local halo density have been placed by the Axion Dark Matter eXperiment. I'll give a status report on ADMX and its upgrade presently under construction. I'll also report on recent results from solar axion searches and laser experiments.

  13. Kinetic Gravity Braiding and axion inflation

    E-Print Network [OSTI]

    Debaprasad Maity

    2013-03-11T23:59:59.000Z

    We constructed a new class of inflationary model with the higher derivative axion field which obeys constant shift symmetry. In the usual axion (natural) inflation, the axion decay constant is predicted to be in the super-Planckian regime which is believed to be incompatible with an effective field theory framework. With a novel mechanism originating from a higher derivative kinetic gravity braiding (KGB) of an axion field we found that there exist a huge parameter regime in our model where axion decay constant could be naturally sub-Planckian. Thanks to the KGB which effectively reduces the Planck constant. This effectively reduced Planck scale provides us the mechanism of further lowering down the speed of an axion field rolling down its potential without introducing super-Planckian axion decay constant. We also find that with that wide range of parameter values, our model induces almost scale invariant power spectrum as observed in CMB experiments.

  14. R-axion detection at LHC

    SciTech Connect (OSTI)

    Goh, Hock-Seng; /UC, Berkeley /LBL, Berkeley; Ibe, Masahiro; /SLAC

    2009-06-19T23:59:59.000Z

    Supersymmetric models with spontaneously broken approximate R-symmetry contains a light spin 0 particle, the R-axion. The properties of the particle can be a powerful probe of the structure of the new physics. In this paper, we discuss the possibilities of the R-axion detection at the LHC experiments. It is challenge to observe this light particle in the LHC environment. However, for typical values in which the mass of the R-axion is a few hundred MeV, we show that those particles can be detected by searching for displaced vertices from R-axion decay.

  15. ccsd00000764 AXION BREMSSTRAHLUNG

    E-Print Network [OSTI]

    ccsd­00000764 (version 1) : 20 Oct 2003 AXION BREMSSTRAHLUNG D.V. GAL'TSOV #3; , E.Yu. MELKUMOVA #3 axion production is proposed: axion bremsstrahlung from collisions of straight global strings. This e#11;ect is of the second order in the axion coupling constant, but the resulting cosmological estimate

  16. Experimental probes of axions

    SciTech Connect (OSTI)

    Chou, Aaron S.; /Fermilab

    2009-10-01T23:59:59.000Z

    Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

  17. Tokyo Axion Helioscope

    SciTech Connect (OSTI)

    Minowa, Makoto [Department of Physics and RESCEU, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2010-08-30T23:59:59.000Z

    The idea of a magnetic axion helioscope was first proposed by Pierre Sikivie in 1983. Tokyo axion helioscope was built exploiting its detection principle with a dedicated cryogen-free superconducting magnet and PIN photodiodes for x-ray detectors. Solar axions, if exist, would be converted into x-ray photons in the magnetic field. Conversion is coherently enhanced even for massive axions by filling the conversion region with helium gas. Its start up, search results so far and prospects are presented.

  18. Dark matter axions `96

    SciTech Connect (OSTI)

    Sikivie, P.

    1996-12-31T23:59:59.000Z

    This report discusses why axions have been postulated to exist, what cosmology implies about their presence as cold dark matter in the galactic halo, how axions might be detected in cavities wherein strong magnetic fields stimulate their conversion into photons, and relations between axions` energy spectra and galactic halos` properties.

  19. CMB probes on the correlated axion isocurvature perturbation

    E-Print Network [OSTI]

    Kenji Kadota; Jinn-Ouk Gong; Kiyotomo Ichiki; Takahiko Matsubara

    2015-01-22T23:59:59.000Z

    We explore the possible cosmological consequence of the gravitational coupling between the inflaton and axion-like fields. In view of the forthcoming cosmic microwave background (CMB) polarization and lensing data, we study the sensitivity of the CMB data on the cross-correlation between the curvature and axion isocurvature perturbations. Through a concrete example, we illustrate the explicit dependence of the scale dependent cross-correlation power spectrum on the axion parameters.

  20. Tokyo Axion Helioscope

    E-Print Network [OSTI]

    M. Minowa; Y. Inoue; Y. Akimoto; R. Ohta; T. Mizumoto; A. Yamamoto

    2008-09-03T23:59:59.000Z

    A new search result of the Tokyo axion helioscope is presented. The axion helioscope consists of a dedicated cryogen-free 4T superconducting magnet with an effective length of 2.3 m and PIN photodiodes as x-ray detectors. Solar axions, if exist, would be converted into X-ray photons through the inverse Primakoff process in the magnetic field. Conversion is coherently enhanced even for massive axions by filling the conversion region with helium gas. The present third phase measurement sets a new limit of g_{a\\gamma\\gamma}axion mass of 0.84

  1. Axion braneworld cosmology

    E-Print Network [OSTI]

    Cosimo Bambi; Masahiro Kawasaki; Federico R. Urban

    2009-03-26T23:59:59.000Z

    We study axion cosmology in a 5D Universe, in the case of flat and warped extra dimension. The comparison between theoretical predictions and observations constrains the 5D axion decay constant and the 5D Planck mass, which has to be taken into account in building 5D axion models. The framework developed in this paper can be readily applied to other bulk fields in brane universes.

  2. Axion braneworld cosmology

    SciTech Connect (OSTI)

    Bambi, Cosimo [IPMU, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); Kawasaki, Masahiro [IPMU, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan); ICRR, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Urban, Federico R. [UBC, Department of Physics and Astronomy, Vancouver, B.C. V6T 1Z1 (Canada); KITPC, Chinese Academy of Sciences, Beijing, 100190 (China)

    2009-07-15T23:59:59.000Z

    We study axion cosmology in a 5D universe, in the case of flat and warped extra dimensions. The comparison between theoretical predictions and observations constrains the 5D axion decay constant and the 5D Planck mass, which have to be taken into account in building 5D axion models. The framework developed in this paper can be readily applied to other bulk fields in brane universes.

  3. Dimming Supernovae by Axions

    E-Print Network [OSTI]

    We considered a model with a hypothetical axion (a type of particle that appears in many models of new physics, including string theory). ...

  4. Fermion dispersion in axion medium

    E-Print Network [OSTI]

    N. V. Mikheev; E. N. Narynskaya

    2008-12-02T23:59:59.000Z

    The interaction of a fermion with the dense axion medium is investigated for the purpose of finding an axion medium effect on the fermion dispersion. It is shown that axion medium influence on the fermion dispersion under astrophysical conditions is negligible small if the correct Lagrangian of the axion-fermion interaction is used.

  5. Axion Quintessence Revisited Carl Gardner

    E-Print Network [OSTI]

    Gardner, Carl

    Axion Quintessence Revisited Carl Gardner School of Mathematical & Statistical Sciences Arizona;Axion Quintessence Define /MP Focus on stable & unstable axion quintessence with DE,0 = 0.72 & -1 axion quintessence V() = A cos(), 0 i/ 0.23 produces a universe like

  6. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2014-03-21T23:59:59.000Z

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  7. Axion dark matter searches

    SciTech Connect (OSTI)

    Stern, Ian P. [Department of Physics, Univerisity of Florida, Gainesville, FL 32611-8440 (United States); Collaboration: ADMX Collaboration; ADMX-HF Collaboration

    2014-06-24T23:59:59.000Z

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a ?eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 ?eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  8. Nonabelian Strings and Axion

    E-Print Network [OSTI]

    A. Gorsky; M. Shifman; A. Yung

    2006-01-18T23:59:59.000Z

    We address two distinct but related issues: (i) the impact of (two-dimensional) axions in a two-dimensional theory known to model confinement, the CP(N-1) model; (ii) bulk axions in four-dimensional Yang-Mills theory supporting non-Abelian strings. In the first case n, \\bar n kinks play the role of "quarks." They are known to be confined. We show that introduction of axions leads to deconfinement (at very large distances). This is akin to the phenomenon of wall liberation in four-dimensional Yang-Mills theory. In the second case we demonstrate that the bulk axion does not liberate confined (anti)monopoles, in contradistinction with the two-dimensional model. A novel physical effect which we observe is the axion radiation caused by monopole-antimonopole pairs attached to the non-Abelian strings.

  9. Weak Gravity Strongly Constrains Large-Field Axion Inflation

    E-Print Network [OSTI]

    Ben Heidenreich; Matthew Reece; Tom Rudelius

    2015-06-10T23:59:59.000Z

    Models of large-field inflation based on axion-like fields with shift symmetries can be simple and natural, and make a promising prediction of detectable primordial gravitational waves. The Weak Gravity Conjecture is known to constrain the simplest case in which a single axion descends from a gauge field in an extra dimension. By supplementing the Weak Gravity Conjecture with considerations of how the mass spectrum of the theory varies across the axion moduli space, we obtain more powerful constraints that apply to a variety of multi-axion theories including N-flation and alignment models. In every case that we consider, plausible assumptions lead to field ranges that cannot be parametrically larger than the Planck scale. Our results are strongly suggestive of a general inconsistency in models of large-field inflation based on axions, and possibly of a more general principle forbidding super-Planckian field ranges.

  10. Weak Gravity Strongly Constrains Large-Field Axion Inflation

    E-Print Network [OSTI]

    Heidenreich, Ben; Rudelius, Tom

    2015-01-01T23:59:59.000Z

    Models of large-field inflation based on axion-like fields with shift symmetries can be simple and natural, and make a promising prediction of detectable primordial gravitational waves. The Weak Gravity Conjecture is known to constrain the simplest case in which a single axion descends from a gauge field in an extra dimension. By supplementing the Weak Gravity Conjecture with considerations of how the mass spectrum of the theory varies across the axion moduli space, we obtain more powerful constraints that apply to a variety of multi-axion theories including N-flation and alignment models. In every case that we consider, plausible assumptions lead to field ranges that cannot be parametrically larger than the Planck scale. Our results are strongly suggestive of a general inconsistency in models of large-field inflation based on axions, and possibly of a more general principle forbidding super-Planckian field ranges.

  11. Future cosmological sensitivity for hot dark matter axions

    E-Print Network [OSTI]

    Archidiacono, Maria; Hamann, Jan; Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y Y

    2015-01-01T23:59:59.000Z

    We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for hot dark matter. Nonetheless, the lowest accessible axion masses are limited by the fact that axions lighter than $\\sim 0.15$ eV decouple before the QCD epoch, assumed here to occur at a temperature $T_{\\rm QCD} \\sim 170$ MeV; this leaves an axion population of such low density that its late-time cosmological impact is negligible. For larger axion masses, $m_a \\gtrsim 0.15$ eV, where axions remain in equilibrium until after the QCD phase transition, we find that a Euclid-like survey combined with Planck CMB data can detect $m_a$ at very high significance. Our conclusions are robust against assumptions about prior knowledge of the neutrino mass. Given that the proposed IAXO solar axion search is sensitive to $m_a\\lesssim 0.2$ eV, the axion mass range probed by cosmology is n...

  12. Dark matter axions revisited

    SciTech Connect (OSTI)

    Visinelli, Luca; Gondolo, Paolo [Department of Physics, University of Utah, 115 S 1400 E 201, Salt Lake City, Utah 84102 (United States)

    2009-08-01T23:59:59.000Z

    We study for what specific values of the theoretical parameters the axion can form the totality of cold dark matter. We examine the allowed axion parameter region in the light of recent data collected by the WMAP5 mission plus baryon acoustic oscillations and supernovae, and assume an inflationary scenario and standard cosmology. We also upgrade the treatment of anharmonicities in the axion potential, which we find important in certain cases. If the Peccei-Quinn symmetry is restored after inflation, we recover the usual relation between axion mass and density, so that an axion mass m{sub a}=(85{+-}3) {mu}eV makes the axion 100% of the cold dark matter. If the Peccei-Quinn symmetry is broken during inflation, the axion can instead be 100% of the cold dark matter for m{sub a}<15 meV provided a specific value of the initial misalignment angle {theta}{sub i} is chosen in correspondence to a given value of its mass m{sub a}. Large values of the Peccei-Quinn symmetry breaking scale correspond to small, perhaps uncomfortably small, values of the initial misalignment angle {theta}{sub i}.

  13. On the robustness of cosmological axion mass limits

    E-Print Network [OSTI]

    Di Valentino, Eleonora; Giusarma, Elena; Mena, Olga

    2015-01-01T23:59:59.000Z

    We present cosmological bounds on the thermal axion mass in an extended cosmological scenario in which the primordial power spectrum of scalar perturbations differs from the usual power-law shape predicted by the simplest inflationary models. The power spectrum is instead modeled by means of a "piecewise cubic Hermite interpolating polynomial" (PCHIP). When using Cosmic Microwave Background measurements combined with other cosmological data sets, the thermal axion mass constraints are degraded only slightly. The addition of the measurements of $\\sigma_8$ and $\\Omega_m$ from the 2013 Planck cluster catalogue on galaxy number counts relaxes the bounds on the thermal axion mass, mildly favouring a $\\sim 1$~eV axion mass, regardless of the model adopted for the primordial power spectrum.

  14. Best Power International LLC | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomass ConversionsSouth Carolina: EnergyConnecticut:NewCarolina:Power International

  15. International Power Corporation Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunanInformation source History View NewInternational Power

  16. Axions in gauge mediation

    SciTech Connect (OSTI)

    Carpenter, Linda M.; Dine, Michael; Festuccia, Guido; Ubaldi, Lorenzo [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz California 95064 (United States)

    2009-12-15T23:59:59.000Z

    In supersymmetric theories, the presence of axions usually implies the existence of a noncompact, (pseudo)moduli space. In gauge-mediated models, the axion would seem a particularly promising dark matter candidate. The cosmology of the moduli then constrains the gravitino mass and the axion decay constant; the former cannot be much below 10 MeV; the latter cannot be much larger than 10{sup 13} GeV. Axinos, when identifiable, are typically heavy and do not play an important role in cosmology.

  17. Revisiting the Impact of Axions in the Cooling of White Dwarfs

    E-Print Network [OSTI]

    Brenda Melendez; Marcelo Miller Bertolami; Leandro Althaus

    2012-10-01T23:59:59.000Z

    It has been shown that the shape of the luminosity function of white dwarfs can be a powerful tool to check for the possible existence of DFSZ-axions. In particular, Isern et al. (2008) showed that, if the axion mass is of the order of a few meV, then the white dwarf luminosity function is sensitive enough to detect their existence. For axion masses of about $m_a > 5$ meV the axion emission can be a primary cooling mechanism for the white dwarf and the feedback of the axion emission into the thermal structure of the white dwarf needs to be considered. Here we present computations of white dwarf cooling sequences that take into account the effect of axion emission in a self consistent way by means of full stellar evolution computations. Then, we study and discuss the impact of the axion emission in the white dwarf luminosity function.

  18. Towards a realistic axion star

    E-Print Network [OSTI]

    J. Barranco; A. Bernal

    2008-08-01T23:59:59.000Z

    In this work we estimate the radius and the mass of a self-gravitating system made of axions. The quantum axion field satisfies the Klein-Gordon equation in a curved space-time and the metric components of this space-time are solutions to the Einstein equations with a source term given by the vacuum expectation value of the energy-momentum operator constructed from the axion field. As a first step towards an axion star we consider the up to the sixth term in the axion potential expansion. We found that axion stars would have masses of the order of asteroids and radius of the order of few centimeters.

  19. Astrophysical Axion Bounds

    E-Print Network [OSTI]

    Georg G. Raffelt

    2006-11-28T23:59:59.000Z

    Axion emission by hot and dense plasmas is a new energy-loss channel for stars. Observational consequences include a modification of the solar sound-speed profile, an increase of the solar neutrino flux, a reduction of the helium-burning lifetime of globular-cluster stars, accelerated white-dwarf cooling, and a reduction of the supernova SN 1987A neutrino burst duration. We review and update these arguments and summarize the resulting axion constraints.

  20. The hunt for axions

    E-Print Network [OSTI]

    Ringwald, Andreas

    2015-01-01T23:59:59.000Z

    Many theoretically well-motivated extensions of the Standard Model of particle physics predict the existence of the axion and further ultralight axion-like particles. They may constitute the mysterious dark matter in the universe and solve some puzzles in stellar and high-energy astrophysics. There are new, relatively small experiments around the globe, which started to hunt for these elusive particles and complement the accelerator based search for physics beyond the Standard Model.

  1. Resonant mechanism of axion photoproduction in a magnetized electron gas

    SciTech Connect (OSTI)

    Skobelev, V. V. [Moscow State Industrial University (Russian Federation)], E-mail: V.Skobelev@inbox.ru

    2007-11-15T23:59:59.000Z

    It was shown that the contribution of diagrams with electron-positron vacuum excitation in a strong magnetic field B >> B{sub 0} = m{sup 2}/e = 4.41 x 10{sup 13} G in the Compton mechanism of axion production {gamma}e {sup {yields}} ae at temperatures on the order of the axion mass exceeds the contribution of the 'simple' Compton diagram and the contribution of the neutrino production {gamma}e {sup {yields}} ({nu}{nu}-bar)e to the radiation power by many orders of magnitude. The conclusion is made on the probable axionic nature of the cold hidden mass of the Universe.

  2. Photon propagator for axion electrodynamics

    SciTech Connect (OSTI)

    Itin, Yakov [Institute of Mathematics, Hebrew University of Jerusalem, Givat Ram, Jerusalem, 91904 (Israel) and Jerusalem College of Technology, P.O.B. 16031, Jerusalem, 91160 (Israel)

    2007-10-15T23:59:59.000Z

    The axion modified electrodynamics is usually used as a model for description of possible violation of Lorentz invariance in field theory. The low-energy manifestation of Lorentz violation can hopefully be observed in experiments with electromagnetic waves. It justifies the importance of studying how a small axion addition can modify the wave propagation. Although a constant axion does not contribute to the dispersion relation at all, even a slowly varying axion field destroys the light cone structure. In this paper, we study the wave propagation in the axion modified electrodynamics in the framework of the premetric approach. In addition to the modified dispersion relation, we derive the axion generalization of the photon propagator in Feynman and Landau gauge. Our consideration is free of the usual restriction to the constant gradient axion field. It is remarkable that the axion modified propagator is Hermitian. Consequently, the dissipation effects are absent even in the phenomenological model considered here.

  3. Final Report: Axion "Roadmap" Workshop

    SciTech Connect (OSTI)

    Rosenberg, Leslie J

    2013-03-19T23:59:59.000Z

    Final report for "Vistas in Axion Physics: A Roadmap for Theoretical and Experimental Axion Physics through 2025", which was held at the University of Washington, INT, from April 23 - 26, 2012.

  4. Axion helioscopes update: the status of CAST and IAXO

    E-Print Network [OSTI]

    T. Dafni; F. J. Iguaz; on behalf of the CAST; IAXO collaborations

    2015-01-07T23:59:59.000Z

    Almost 35 years since their suggestion as a good solution to the strong CP-problem, axions remain one of the few viable candidates for the Dark Matter, although still eluding detection. Most of the methods for their detection are based on their coupling to photons, one of the most sensitive ones being the helioscope technique. We report on the current status of the CERN Axion Solar Telescope and the future International Axion Observatory (IAXO). Recent results from the second part of CAST phase II, where the magnet bores were filled with 3He gas at variable pressure achieving sensibilities on the axion mass up to 1.2 eV, are presented. Currently, CAST is expecting to improve its sensitivity to solar axions with rest mass below 0.02 eV/c^2 after the upgrade of the X-ray detectors and with the implementation of a second X-ray optic. At the same time, it is exploring other possibilities at the low energy physics frontier. On the other hand IAXO, the fourth generation axion helioscope, aims to improve CAST's performance in terms of axion-photon coupling by 1-1.5 orders of magnitude. The details of the project building a dedicated magnet, optics and X-ray detectors are given.

  5. Axion Cosmology Revisited

    E-Print Network [OSTI]

    Olivier Wantz; E. P. S. Shellard

    2011-02-13T23:59:59.000Z

    The misalignment mechanism for axion production depends on the temperature-dependent axion mass. The latter has recently been determined within the interacting instanton liquid model (IILM), and provides for the first time a well-motivated axion mass for all temperatures. We reexamine the constraints placed on the axion parameter space in the light of this new mass function. We find an accurate and updated constraint $ f_a \\le 2.8(\\pm2)\\times 10^{11}\\units{GeV}$ or $m_a \\ge 21(\\pm2) \\units{\\mu eV}$ from the misalignment mechanism in the classic axion window (thermal scenario). However, this is superseded by axion string radiation which leads to $ f_a \\lesssim 3.2^{+4}_{-2} \\times 10^{10} \\units{GeV}$ or $m_a \\gtrsim 0.20 ^{+0.2}_{-0.1} \\units{meV}$. In this analysis, we take care to precisely compute the effective degrees of freedom and, to fill a gap in the literature, we present accurate fitting formulas. We solve the evolution equations exactly, and find that analytic results used to date generally underestimate the full numerical solution by a factor 2-3. In the inflationary scenario, axions induce isocurvature fluctuations and constrain the allowed inflationary scale $H_I$. Taking anharmonic effects into account, we show that these bounds are actually weaker than previously computed. Considering the fine-tuning issue of the misalignment angle in the whole of the anthropic window, we derive new bounds which open up the inflationary window near $\\theta_a \\to \\pi$. In particular, we find that inflationary dark matter axions can have masses as high as 0.01--1$\\units{meV}$, covering the whole thermal axion range, with values of $H_I$ up to $10^9$GeV. Quantum fluctuations during inflation exclude dominant dark matter axions with masses above $m_a\\lesssim 1$meV.

  6. Axion cosmology revisited

    SciTech Connect (OSTI)

    Wantz, Olivier; Shellard, E. P. S. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2010-12-15T23:59:59.000Z

    The misalignment mechanism for axion production depends on the temperature-dependent axion mass. The latter has recently been determined within the interacting instanton liquid model, and provides for the first time a well-motivated axion mass for all temperatures. We reexamine the constraints placed on the axion parameter space in the light of this new mass function. Taking this mass at face value, we find an accurate and updated constraint f{sub a{<=}}2.8({+-}2)x10{sup 11} GeV or m{sub a{>=}}21({+-}2) {mu}eV from the misalignment mechanism in the classic axion window (thermal scenario). However, this is superseded by axion string radiation which leads to f{sub a} < or approx. 3.2{sub -2}{sup +4}x10{sup 10} GeV or m{sub a} > or approx. 0.20{sub -0.1}{sup +0.2} meV. In this analysis, we take care to precisely compute the effective degrees of freedom and, to fill a gap in the literature, we present accurate fitting formulas. We solve the evolution equations exactly, and find that analytic results used to date generally underestimate the full numerical solution by a factor 2-3. In the inflationary scenario, axions induce isocurvature fluctuations and constrain the allowed inflationary scale H{sub I}. Taking anharmonic effects into account, we show that these bounds are actually weaker than previously computed. Considering the fine-tuning issue of the misalignment angle in the whole of the anthropic window, we derive new bounds which open up the inflationary window near {theta}{sub a{yields}{pi}}. In particular, we find that inflationary dark matter axions can have masses as high as 0.01-1 meV, covering the whole thermal axion range, with values of H{sub I} up to 10{sup 9} GeV. Quantum fluctuations during inflation exclude dominant dark matter axions with masses above m{sub a} < or approx. 1 meV.

  7. The GammeV suite of experimental searches for axion-like particles

    SciTech Connect (OSTI)

    Steffen, Jason H.; /Fermilab; Upadhye, Amol; /KICP, Chicago /Chicago U., EFI

    2009-08-01T23:59:59.000Z

    We report on the design and results of the GammeV search for axion-like particles and for chameleon particles. We also discuss plans for an improved experiment to search for chameleon particles, one which is sensitive to both cosmological and power-law chameleon models. Plans for an improved axion-like particle search using coupled resonant cavities are also presented. This experiment will be more sensitive to axion-like particles than stellar astrophysical models or current helioscope experiments.

  8. Axion domain wall baryogenesis

    E-Print Network [OSTI]

    Daido, Ryuji; Takahashi, Fuminobu

    2015-01-01T23:59:59.000Z

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, $m \\simeq 10^8 -10^{13}$ GeV and $f \\simeq 10^{13} - 10^{16}$ GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  9. A Heterotic QCD Axion

    E-Print Network [OSTI]

    Evgeny I. Buchbinder; Andrei Constantin; Andre Lukas

    2015-02-27T23:59:59.000Z

    We show that a KSVZ axion with a decay constant in the phenomenologically allowed range can be obtained in certain $E_8\\times E_8$ heterotic string models. These models have an enhanced symmetry locus in the moduli space, and a non-universal, Kahler moduli dependent Fayet-Iliopoulos term which vanishes at this locus. Close to this locus the Fayet-Iliopoulos term is small and can lead to an axion decay constant significantly lower than the string scale. In this way, the no-go arguments of Svrcek and Witten, which are based on a universal, dilaton-dependent Fayet-Iliopoulos term, can be avoided. The relevant axion originates from phases of bundle moduli which correspond to deformations away from the enhanced symmetry locus. We construct an explicit example, based on a heterotic line bundle standard model, with all the required ingredients.

  10. F-term Axion Monodromy Inflation

    E-Print Network [OSTI]

    Fernando Marchesano; Gary Shiu; Angel M. Uranga

    2014-10-09T23:59:59.000Z

    The continuous shift symmetry of axions is at the heart of several realizations of inflationary models. In particular, axion monodromy inflation aims at achieving super-Planckian field ranges for the inflaton in the context of string theory. Despite the elegant underlying principle, explicit models constructed hitherto are exceedingly complicated. We propose a new and better axion monodromy inflationary scenario, where the inflaton potential arises from an F-term. We present several scenarios, where the axion arises from the Kaluza-Klein compactification of higher dimensional gauge fields (or p-form potentials) in the presence of fluxes and/or torsion homology. The monodromy corresponds to a change in the background fluxes, and its F-term nature manifests in the existence of domain walls interpolating among flux configurations. Our scenario leads to diverse inflaton potentials, including linear large field behaviour, chaotic inflation, as well as potentials with even higher powers. They provide an elegant set of constructions with properties in the ballpark of the recent BICEP2 observational data on primordial gravitational waves.

  11. Axion hot dark matter bounds after Planck

    SciTech Connect (OSTI)

    Archidiacono, Maria; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus DK-8000 Aarhus C (Denmark); Mirizzi, Alessandro [II. Institut für Theoretische Physik, Universität Hamburg Luruper Chaussee 149, D-22761 Hamburg (Germany); Raffelt, Georg [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) Föhringer Ring 6, D-80805 München (Germany); Wong, Yvonne Y.Y., E-mail: archi@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: alessandro.mirizzi@desy.de, E-mail: raffelt@mpp.mpg.de, E-mail: yvonne.y.wong@unsw.edu.au [School of Physics, The University of New South Wales Sydney NSW 2052 (Australia)

    2013-10-01T23:59:59.000Z

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m{sub a} < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H{sub 0} released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H{sub 0} measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m{sub a} has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H{sub 0} and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from ? m{sub ?} < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.

  12. Isocurvature constraints and anharmonic effects on QCD axion dark matter

    SciTech Connect (OSTI)

    Kobayashi, Takeshi [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 3H8 (Canada); Kurematsu, Ryosuke; Takahashi, Fuminobu, E-mail: takeshi@cita.utoronto.ca, E-mail: rkurematsu@tuhep.phys.tohoku.ac.jp, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

    2013-09-01T23:59:59.000Z

    We revisit the isocurvature density perturbations induced by quantum fluctuations of the axion field by extending a recently developed analytic method and approximations to a time-dependent scalar potential, which enables us to follow the evolution of the axion until it starts to oscillate. We find that, as the initial misalignment angle approaches the hilltop of the potential, the isocurvature perturbations become significantly enhanced, while the non-Gaussianity parameter increases slowly but surely. As a result, the isocurvature constraint on the inflation scale is tightened as H{sub inf}?axion decay constant f{sub a}?<10{sup 10} GeV, near the smaller end of the axion dark matter window. We also derive useful formulae for the power spectrum and non-Gaussianity of the isocurvature perturbations.

  13. Experimental overview of axion searches

    SciTech Connect (OSTI)

    van Bibber, K.

    1995-06-28T23:59:59.000Z

    Experimental methods to search for the ``invisible axion`` (f{sub a} {much_gt} 250 GeV) are reviewed. The report focuses on the axion-photon coupling, both for laboratory experiments as well as those looking for stellar or cosmologically produced axions. The conclusion is that while the axion-photon mixing in principle would permit laboratory axion searches which are broadband in mass, in fact no such experiment could have the sensitivity to the axion, where m{sub afa} {approx} m{sub {pi}f{pi}}. The only experiments which promise to have any chance to find the axion are the microwave cavity experiments, which presume axions to constitute our galactic halo dark matter. The conversion of axions into a monochromatic microwave signal in a resonant circuit affords the experiment the extraordinary sensitivity required to see the axion, at the expense of being narrow-band in mass, i.e. a tuning experiment. Two such efforts are underway in the world.

  14. Cosmological Consequences of String Axions

    SciTech Connect (OSTI)

    Kain, Ben

    2005-12-15T23:59:59.000Z

    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.

  15. Dual Axion Electrodynamics

    E-Print Network [OSTI]

    Luca Visinelli

    2011-11-06T23:59:59.000Z

    The duality relation between the electric and magnetic fields, in the presence of an additional axion-like field, is considered. We derive the new equations that describe the electrodynamics in this model, and we discuss the implications for the conservation of the electric and magnetic four-currents and for the propagation of waves.

  16. Towards a Realistic Axion Star

    SciTech Connect (OSTI)

    Barranco, J. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-360, 01000. Mexico D.F. (Mexico); Bernal, A. [Instituto de Fisica de la Universidad de Guanajuato, C.P. 37150, Leon, Guanajuato (Mexico)

    2008-07-02T23:59:59.000Z

    In this work we estimate the radius and the mass of a self-gravitating system made of axions. The quantum axion field satisfies the Klein-Gordon equation in a curved space-time and the metric components of this space-time are solutions to the Einstein equations with a source term given by the vacuum expectation value of the energy-momentum operator constructed from the axion field. As a first step towards an axion star we consider the up to the {phi}{sup 6} term in the axion potential expansion. We found that axion stars would have masses of the order of asteroids ({approx}10{sup -10}M{center_dot}) and radius of the order {approx} few centimeters.

  17. Establishment of the International Power Institute. Final technical report

    SciTech Connect (OSTI)

    Julius E. Coles

    2000-08-04T23:59:59.000Z

    The International Power Institute, in collaboration with American industries, seeks to address technical, political, economic and cultural issues of developing countries in the interest of facilitating profitable transactions in power related infrastructure projects. IPI works with universities, governments and commercial organizations to render project-specific recommendations for private-sector investment considerations. IPI also established the following goals: Facilitate electric power infrastructure transactions between developing countries and the US power industry; Collaborate with developing countries to identify development strategies to achieve energy stability; and Encourage market driven solutions and work collaboratively with other international trade energy, technology and banking organizations.

  18. Wave propagation in axion electrodynamics

    E-Print Network [OSTI]

    Yakov Itin

    2007-06-20T23:59:59.000Z

    In this paper, the axion contribution to the electromagnetic wave propagation is studied. First we show how the axion electrodynamics model can be embedded into a premetric formalism of Maxwell electrodynamics. In this formalism, the axion field is not an arbitrary added Chern-Simon term of the Lagrangian, but emerges in a natural way as an irreducible part of a general constitutive tensor.We show that in order to represent the axion contribution to the wave propagation it is necessary to go beyond the geometric approximation, which is usually used in the premetric formalism. We derive a covariant dispersion relation for the axion modified electrodynamics. The wave propagation in this model is studied for an axion field with timelike, spacelike and null derivative covectors. The birefringence effect emerges in all these classes as a signal of Lorentz violation. This effect is however completely different from the ordinary birefringence appearing in classical optics and in premetric electrodynamics. The axion field does not simple double the ordinary light cone structure. In fact, it modifies the global topological structure of light cones surfaces. In CFJ-electrodynamics, such a modification results in violation of causality. In addition, the optical metrics in axion electrodynamics are not pseudo-Riemannian. In fact, for all types of the axion field, they are even non-Finslerian.

  19. Cosmological consequences of string axions

    SciTech Connect (OSTI)

    Kain, Ben [Department of Physics, University of California and Theoretical Physics Group, Bldg. 50A5104, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2006-06-15T23:59:59.000Z

    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} > or approx. 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T < or approx. {lambda}{sub QCD}.

  20. Axion Bounds from Precision Cosmology

    SciTech Connect (OSTI)

    Raffelt, G. G. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), 80805 Muenchen (Germany); Hamann, J.; Hannestad, S. [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark); Mirizzi, A. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, 22761 Hamburg (Germany); Wong, Y. Y. Y. [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen, 52056 Aachen (Germany)

    2010-08-30T23:59:59.000Z

    Depending on their mass, axions produced in the early universe can leave different imprints in cosmic structures. If axions have masses in the eV-range, they contribute a hot dark matter fraction, allowing one to constrain m{sub a} in analogy to neutrinos. In the more favored scenario where axions play the role of cold dark matter and if reheating after inflation does not restore the Peccei-Quinn symmetry, the axion field provides isocurvature fluctuations that are severely constrained by precision cosmology. There remains a small sliver in parameter space where isocurvature fluctuations could still show up in future probes.

  1. Topology in QCD and the axion abundance

    E-Print Network [OSTI]

    Ryuichiro Kitano; Norikazu Yamada

    2015-06-01T23:59:59.000Z

    The temperature dependence of the topological susceptibility (chi_t) in QCD essentially determines the abundance of the QCD axion in the Universe, and is commonly estimated, based on the instanton picture, to be a certain negative power of temperature. While lattice QCD should be able to check the instanton picture in principle, the region of the temperature where lattice calculations of chi_t are reliable is rather limited in practice, because existing methods on the lattice will probably fail when chi_t decreases rapidly with temperatures. In this work, two exploratory studies are presented. First, to realize the limitation of temperature we perform lattice calculations of chi_t in the quenched approximation and find that it becomes difficult with a given resource when T > 2 T_c. A possible way out is proposed and some test calculations are given. The absolute value and the temperature dependence of chi_t in real QCD can be significantly different from that in the quenched approximation, and is not well established over a wide range of the temperature above its critical value. Motivated by this fact and precedent arguments which disagree with the conventional instanton picture, we estimate the axion abundance in an extreme case where chi_t decreases much faster than the conventional power-like function. We find a significant enhancement of the axion abundance in such a case.

  2. Axions in String Theory

    SciTech Connect (OSTI)

    Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC; Witten, Edward; /Princeton, Inst. Advanced Study

    2006-06-09T23:59:59.000Z

    In the context of string theory, axions appear to provide the most plausible solution of the strong CP problem. However, as has been known for a long time, in many string-based models, the axion coupling parameter Fa is several orders of magnitude higher than the standard cosmological bounds. We re-examine this problem in a variety of models, showing that Fa is close to the GUT scale or above in many models that have GUT-like phenomenology, as well as some that do not. On the other hand, in some models with Standard Model gauge fields supported on vanishing cycles, it is possible for Fa to be well below the GUT scale.

  3. String compactification, QCD axion and axion-photon-photon coupling

    E-Print Network [OSTI]

    Kang-Sin Choi; Ian-Woo Kim; Jihn E. Kim

    2007-01-13T23:59:59.000Z

    It is pointed out that there exist a few problems to be overcome toward an observable sub-eV QCD axion in superstring compactification. We give a general expression for the axion decay constant. For a large domain wall number $N_{DW}$, the axion decay constant can be substantially lowered from a generic value of a scalar singlet VEV. The Yukawa coupling structure in the recent $Z_{12-I}$ model is studied completely, including the needed nonrenormalizable terms toward realistic quark and lepton masses. In this model we find an approximate global symmetry and vacuum so that a QCD axion results but its decay constant is at the GUT scale. The axion-photon-photon coupling is calculated for a realistic vacuum satisfying the quark and lepton mass matrix conditions. It is the first time calculation of $c_{a\\gamma\\gamma}$ in realistic string compactifications: $c_{a\\gamma\\gamma}={5/3}-1.93\\simeq -0.26$.

  4. Non-Abelian Strings and Axions

    SciTech Connect (OSTI)

    Shifman, M. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN 55455 (United States)

    2010-08-30T23:59:59.000Z

    Axion-like fields can have a strong impact on non-Abelian strings. I discuss axion connection to such strings and its implications in two cases: (i) axion localized on the strings, and (ii) axions propagating in the four-dimensional bulk.

  5. Superconducting Radio Frequency Cavities as Axion Dark Matter Detectors

    E-Print Network [OSTI]

    P. Sikivie

    2013-01-20T23:59:59.000Z

    A modification of the cavity technique for axion dark matter detection is described in which the cavity is driven with input power instead of being permeated by a static magnetic field. A small fraction of the input power is pumped by the axion field to a receiving mode of frequency $\\omega_1$ when the resonance condition $\\omega_1 = \\omega_0 \\pm m_a$ is satisfied, where $\\omega_0$ is the frequency of the input mode and $m_a$ the axion mass. The relevant form factor is calculated for any pair of input and output modes in a cylindrical cavity. The overall search strategy is discussed and the technical challenges to be overcome by an actual experiment are listed.

  6. Cosmological Constant and Axions in String Theory

    SciTech Connect (OSTI)

    Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC

    2006-08-18T23:59:59.000Z

    String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.

  7. Axion Dark Matter Detection using Atomic Transitions

    E-Print Network [OSTI]

    P. Sikivie

    2014-09-09T23:59:59.000Z

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

  8. Revisiting the axion bounds from the Galactic white dwarf luminosity function

    E-Print Network [OSTI]

    Marcelo M. Miller Bertolami; Brenda E. Melendez; Leandro G. Althaus; Jordi Isern

    2014-10-07T23:59:59.000Z

    It has been shown that the shape of the luminosity function of white dwarfs (WDLF) is a powerful tool to check for the possible existence of DFSZ-axions, a proposed but not yet detected type of weakly interacting particles. With the aim of deriving new constraints on the axion mass, we compute in this paper new theoretical WDLFs on the basis of WD evolving models that incorporate for the feedback of axions on the thermal structure of the white dwarf. We find that the impact of the axion emission into the neutrino emission can not be neglected at high luminosities ($M_{\\rm Bol}\\lesssim 8$) and that the axion emission needs to be incorporated self-consistently into the evolution of the white dwarfs when dealing with axion masses larger than $m_a\\cos^2\\beta\\gtrsim 5$ meV (i.e. axion-electron coupling constant $g_{ae}\\gtrsim 1.4\\times 10^{-13}$). We went beyond previous works by including 5 different derivations of the WDLF in our analysis. Then we have performed $\\chi^2$-tests to have a quantitative measure of the assessment between the theoretical WDLFs ---computed under the assumptions of different axion masses and normalization methods--- and the observed WDLFs of the Galactic disk. While all the WDLF studied in this work disfavour axion masses in the range suggested by asteroseismology ($m_a\\cos^2\\beta\\gtrsim 10$ meV; $g_{ae}\\gtrsim 2.8\\times 10^{-13}$) lower axion masses can not be discarded from our current knowledge of the WDLF of the Galactic Disk. A larger set of completely independent derivations of the WDLF of the galactic disk as well as a detailed study of the uncertainties of the theoretical WDLFs is needed before quantitative constraints on the axion-electron coupling constant can be made.

  9. Axionic dark energy and a composite QCD axion

    SciTech Connect (OSTI)

    Kim, Jihn E. [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Nilles, Hans Peter, E-mail: jekim@ctp.snu.ac.kr, E-mail: nilles@th.physik.uni-bonn.de [Bethe Center for Theoretical Physics and Physikalisches Institut, Universitaet Bonn, D-53115, Bonn (Germany)

    2009-05-15T23:59:59.000Z

    We discuss the idea that the model-independent (MI) axion of string theory is the source of quintessential dark energy. The scenario is completed with a composite QCD axion from hidden sector squark condensation that could serve as dark matter candidate. The mechanism relies on the fact that the hidden sector anomaly contribution to the composite axion is much smaller than the QCD anomaly term. This intuitively surprising scenario is based on the fact that below the hidden sector scale {Lambda}{sub h} there are many light hidden sector quarks. Simply, by counting engineering dimensions the hidden sector instanton potential can be made negligible compared to the QCD anomaly term.

  10. Sandia Energy - Solar Power International (SPI) Workshop

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol Home Distribution GridDocumentsInstitute ofSiting andSolar GlarePower

  11. Axion dark matter, solitons, and the cusp-core problem

    E-Print Network [OSTI]

    Marsh, David J E

    2015-01-01T23:59:59.000Z

    Self-gravitating bosonic fields can support stable and localised field configurations. For real fields, these solutions oscillate in time and are known as oscillatons. The density profile is static, and is soliton. Such solitons should be ubiquitous in models of axion dark matter, with the soliton characteristic mass and size depending on some inverse power of the axion mass. Stable configurations of non-relativistic axions are studied numerically using the Schr\\"{o}dinger-Poisson system. This method, and the resulting soliton density profiles, are reviewed. Using a scaling symmetry and the uncertainty principle, the core size of the soliton can be related to the central density and axion mass, $m_a$, in a universal way. Solitons have a constant central density due to pressure-support, unlike the cuspy profile of cold dark matter (CDM). One consequence of this fact is that solitons composed of ultra-light axions (ULAs) may resolve the `cusp-core' problem of CDM. In DM halos, thermodynamics will lead to a CDM-...

  12. Probing axions with radiation from magnetic stars

    SciTech Connect (OSTI)

    Lai Dong; Heyl, Jeremy [Center for Radiophysics and Space Research, Department of Astronomy, Cornell University, Ithaca, New York 14853 (United States); Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada)

    2006-12-15T23:59:59.000Z

    Recent experiments suggest that polarized photons may couple significantly to pseudoscalar particles such as axions. We study the possible observational signatures of axion-photon coupling for radiation from magnetic stars, with particular focus on neutron stars. We present general methods for calculating the axion-photon conversion probability during propagation through a varying magnetized vacuum as well as across an inhomogeneous atmosphere. Partial axion-photon conversion may take place in the vacuum region outside the neutron star. Strong axion-photon mixing occurs due to a resonance in the atmosphere and, depending on the axion coupling strength and other parameters, significant axion-photon conversion can take place at the resonance. Such conversions may produce observable effects on the radiation spectra and polarization signals from the star. We also apply our results to axion-photon propagation in the Sun and in magnetic white dwarfs. We find that there is no appreciable conversion of solar axions to photons during the propagation.

  13. Non-gaussianity in axion N-flation models Quadratic and $??^4$ plus axion potentials

    E-Print Network [OSTI]

    Mehran Kamarpour

    2012-10-27T23:59:59.000Z

    In this paper we investigate large non-gaussianity in axion N-flation models, taking account while dynamically a large number of axions begin away from the hilltop region(come down from the hill) and so serve only to be the source of the Hubble rate. Therefore the single field stays closest to the hilltop sources the non-Gaussianity. In this case most of axions can be replaced by a single effective field with a quadratic potential. So our potential will contain two fields. The full cosine is responsible for the axion closest to hilltop and quadratic term which is a source for Hubble rate [4]. We obtain power spectrum, spectral index and non-gaussianity parameter, then we impose conditions from WMAP for power spectrum and spectral index and see how large on non-gaussianity parameter it is possible to achieve with such conditions. Finally we swap quadratic term to {\\lambda}{\\phi}^4 and see whether this makes it harder or easier to achieve large non-gaussianity.We find large non-gaussianity is achievable by imposing data from WMAP conditional on axion decay constant f has reasonable value in connection with Planck mass and by requiring number of e-folds must be bounded between 40-60.When we swap to {\\lambda}{\\phi}^4 we find that it is harder to achieve non-Gaussianity, because we are imposed to investigate only {\\lambda}{\\phi}^4 domination in consistency with WMAP data for spectral index. Although, in this case we find that large non-gaussianity is still achievable. Finally we verify imposing the condition for spectral index to be nearly one and find acceptable and detectable value for non-gaussianity typically of order of 10 and 100 depending on value of decay constant f.Swapping to {\\lambda}{\\phi}^4 in this case does not give us any significant relation. In this paper we consider models which can generate large non-gaussianity. We restrict ourselves to axion N-flation models.

  14. Is the Universal String Axion the QCD Axion

    SciTech Connect (OSTI)

    Gaillard, Mary K.; Kain, Ben

    2005-10-14T23:59:59.000Z

    We consider the class of effective supergravity theories from the weakly coupled heterotic string in which local supersymmetry is broken by gaugino condensation in a hidden sector, with dilaton stabilization achieved through corrections to the classical dilaton Kahler potential. If there is a single hidden condensing (simple) gauge group, the axion is massless (up to contributions from higher dimension operators) above the QCD condensation scale. We show how the standard relation between the axion mass and its Planck scale coupling constant is modified in this class of models due to a contribution to the axion-gluon coupling that appears below the scale of supersymmetry breaking when gluinos are integrated out. In particular there is a point of enhanced symmetry in parameter space where the axion mass is suppressed. We revisit the question of the universal axion as the Peccei-Quinn axion in the light of these results, and find that the strong CP problem is avoided in most compactifications of the weakly coupled heterotic string.

  15. Wind Power Forecasting Error Distributions: An International Comparison; Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Lew, D.; Milligan, M.; Holttinen, H.; Sillanpaa, S.; Gomez-Lazaro, E.; Scharff, R.; Soder, L.; Larsen, X. G.; Giebel, G.; Flynn, D.; Dobschinski, J.

    2012-09-01T23:59:59.000Z

    Wind power forecasting is expected to be an important enabler for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that do occur can be critical to system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.

  16. Axion Battery Products Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof EnergyInnovation in Carbon CaptureAtria PowerAxeon Technology Ltd Jump to:AxioAxion

  17. Axions in gravity with torsion

    E-Print Network [OSTI]

    Oscar Castillo-Felisola; Cristobal Corral; Sergey Kovalenko; Ivan Schmidt; Valery E. Lyubovitskij

    2015-04-13T23:59:59.000Z

    We study a scenario allowing a solution of the strong charge parity problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so-called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the viewpoint of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.

  18. Axions in gravity with torsion

    E-Print Network [OSTI]

    Castillo-Felisola, Oscar; Kovalenko, Sergey; Schmidt, Ivan; Lyubovitskij, Valery E

    2015-01-01T23:59:59.000Z

    We study a scenario allowing a solution of the strong CP-problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the view point of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.

  19. CAST results and Axion review

    E-Print Network [OSTI]

    T. Geralis; for the CAST collaboration

    2009-05-26T23:59:59.000Z

    We present results from the CERN Axion Solar Telescope (CAST) and the Axion Dark Matter eXperiment (ADMX), together with a brief review on prospects on Axion searches with a variety of experimental techniques. CAST has explored masses up to 0.64 eV setting the most stringent limit on the axion-photon coupling, apart for the micro-eV region where ADMX is the most competitive experiment. CAST is aiming at surpassing the 1eV WMAP upper limit and possibly revisiting the operation in vacuum with extra sensitive X-ray detectors, while ADMX, using improved extra sensitive SQUID amplifiers will explore the micro-eV mass range.

  20. Ultrasensitive Searches for the Axion

    SciTech Connect (OSTI)

    van Bibber, K A; Rosenberg, L J

    2006-07-14T23:59:59.000Z

    The axion, a hypothetical elementary particle arising from a compelling solution to the strong-CP problem, has eluded discovery for three decades. Experiments based on coherent axion-photon mixing in strong magnetic fields are just now reaching the sensitivity to detect it, either as the dark matter or as a component of the solar flux. Although of lower sensitivity, purely laboratory experiments hold potential for surprise.

  1. Updated Axion CDM energy density

    E-Print Network [OSTI]

    Ji-Haeng Huh

    2008-10-08T23:59:59.000Z

    We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Lambda_{QCD}, the current quark masses m_q's and the Peccei-Quinn scale F_a, including firstly introduced 1.85 factor which is from the initial overshoot.

  2. Dark matter axions and caustic rings

    SciTech Connect (OSTI)

    Sikivie, P.

    1997-11-01T23:59:59.000Z

    This report contains discussions on the following topics: the strong CP problem; dark matter axions; the cavity detector of galactic halo axions; and caustic rings in the density distribution of cold dark matter halos.

  3. New Atomic probes for Dark Matter detection: Axions, Axion-like particles and Topological Defects

    E-Print Network [OSTI]

    Yevgeny V. Stadnik; Victor V. Flambaum

    2014-09-10T23:59:59.000Z

    We present a brief overview of recently proposed detection schemes for axion, axion-like pseudoscalar particle and topological defect dark matter. We focus mainly on the possibility of using atomic and molecular systems for dark matter detection. For axions and axion-like particles, these methods are complementary probes to ongoing photon-axion interconversion experiments and astrophysical observations. For topological defects, these methods are complementary to conventional astrophysical search schemes based on gravitational signatures.

  4. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect (OSTI)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01T23:59:59.000Z

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  5. Intermediate Scale Accidental Axion and ALPs

    E-Print Network [OSTI]

    Alex G. Dias

    2014-09-28T23:59:59.000Z

    We discuss the problem of constructing models containing an axion and axion-like particles, motivated by astrophysical observations, with decay constants at the intermediate scale ranging from $10^9$GeV to $10^{13}$GeV. We present examples in which the axion and axion-like particles arise accidentally as pseudo Nambu-Goldstone bosons of automatic global chiral symmetries, in models having exact discrete symmetries.

  6. Production of Axions by Cosmic Magnetic Helicity

    E-Print Network [OSTI]

    L. Campanelli; M. Giannotti

    2006-04-05T23:59:59.000Z

    We investigate the effects of an external magnetic helicity production on the evolution of the cosmic axion field. It is shown that a helicity larger than (few \\times 10^{-15} G)^2 Mpc, if produced at temperatures above a few GeV, is in contradiction with the existence of the axion, since it would produce too much of an axion relic abundance.

  7. How a cold axion background influences photons

    E-Print Network [OSTI]

    Domènec Espriu; Albert Renau

    2011-11-14T23:59:59.000Z

    A cold relic axion condensate resulting from vacuum misalignment in the early universe oscillates with a frequency \\sim m_a, where m_a is the axion mass. We summarize how the properties of photons propagating in such a medium are modified. Although the effects are small due to the magnitude of the axion-photon coupling, some consequences are striking.

  8. Axion-medium effect on fermion dispersion

    SciTech Connect (OSTI)

    Mikheev, N. V., E-mail: mikheev@uniyar.ac.ru; Narynskaya, E. N., E-mail: elenan@uniyar.ac.r [Yaroslavl State University (Russian Federation)

    2008-08-15T23:59:59.000Z

    The interaction of fermions with a dense axion medium is considered with the aim of studying the effect of the axionmediumon fermion dispersion. It is shown that, if use is made of a correct Lagrangian for axion-fermion interaction, the effect of a dense axion medium on fermion dispersion is negligible under real astrophysical conditions.

  9. The Fully Quantized Axion and Dark Energy

    E-Print Network [OSTI]

    Dylan Tanner

    2012-12-17T23:59:59.000Z

    This letter reviews the exact evolution equation for the axion effective potential with the axion scale factor f and phenomenological consequences of the flat effective potential solution are discussed. It is shown that the corresponding vacuum energy can be consistent with Dark Energy, and we compare this result to other studies relating the axion and Dark Energy.

  10. International reservoir operations agreement helps NW fish & power

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergy International Fuel7 12 BONNEVILLE POWER

  11. Axion dark matter, solitons, and the cusp-core problem

    E-Print Network [OSTI]

    David J. E. Marsh; Ana-Roxana Pop

    2015-06-17T23:59:59.000Z

    Self-gravitating bosonic fields can support stable and localised field configurations. For real fields, these solutions oscillate in time and are known as oscillatons. The density profile is static, and is soliton. Such solitons should be ubiquitous in models of axion dark matter, with the soliton characteristic mass and size depending on some inverse power of the axion mass. Stable configurations of non-relativistic axions are studied numerically using the Schr\\"{o}dinger-Poisson system. This method, and the resulting soliton density profiles, are reviewed. Using a scaling symmetry and the uncertainty principle, the core size of the soliton can be related to the central density and axion mass, $m_a$, in a universal way. Solitons have a constant central density due to pressure-support, unlike the cuspy profile of cold dark matter (CDM). One consequence of this fact is that solitons composed of ultra-light axions (ULAs) may resolve the `cusp-core' problem of CDM. In DM halos, thermodynamics will lead to a CDM-like Navarro-Frenk-White profile at large radii, with a central soliton core at small radii. Using Monte-Carlo techniques to explore the possible density profiles of this form, a fit to stellar-kinematical data of dwarf spheroidal galaxies is performed. In order for ULAs to resolve the cusp-core problem (without recourse to baryon feedback or other astrophysical effects) the axion mass must satisfy $m_a<1.1\\times 10^{-22}\\text{ eV}$ at 95\\% C.L. On the other hand, ULAs with $m_a\\lesssim 1\\times 10^{-22}\\text{ eV}$ are in some tension with cosmological structure formation. An axion solution to the cusp-core problem thus makes novel predictions for future measurements of the epoch of reionisation. On the other hand, this can be seen as evidence that structure formation could soon impose a \\emph{Catch 22} on axion/scalar field DM, similar to the case of warm DM.

  12. Inflationary Axion Cosmology Beyond Our Horizon

    E-Print Network [OSTI]

    David B. Kaplan; Ann E. Nelson

    2008-09-07T23:59:59.000Z

    In theories of axion dark matter with large axion decay constant, temperature variations in the CMB are extremely sensitive to perturbations in the initial axion field, allowing one to place a lower bound on the total amount of inflation. The most stringent bound comes from axion strings, which for axion decay constant f=10^17 GeV would currently be observable at a distance of 6 x 10^16 light-years, nearly ten million times as far away as our horizon.

  13. Resonantly-enhanced axion-photon regeneration

    SciTech Connect (OSTI)

    Mueller, Guido; Sikivie, Pierre; Tanner, David B. [Department of Physics, University of Florida, Gainesville, FL 32611 (United States); Bibber, Karl van [Naval Postgraduate School, Monterey, CA 93943 (United States)

    2010-08-30T23:59:59.000Z

    A resonantly-enhanced photon-regeneration experiment to search for the axion or axion-like particles is discussed. Photons enter a strong magnetic field and some are converted to axions; the axions can pass through an opaque wall and some may convert back to photons in a second high-field region. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon regeneration magnet. The optics for this experiment are discussed, with emphasis on the alignment of the two cavities.

  14. Axions, inflation and the anthropic principle

    SciTech Connect (OSTI)

    Mack, Katherine J., E-mail: mack@ast.cam.ac.uk [Kavli Institute for Cosmology, Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)

    2011-07-01T23:59:59.000Z

    The QCD axion is the leading solution to the strong-CP problem, a dark matter candidate, and a possible result of string theory compactifications. However, for axions produced before inflation, symmetry-breaking scales of f{sub a}?>10{sup 12} GeV (which are favored in string-theoretic axion models) are ruled out by cosmological constraints unless both the axion misalignment angle ?{sub 0} and the inflationary Hubble scale H{sub I} are extremely fine-tuned. We show that attempting to accommodate a high-f{sub a} axion in inflationary cosmology leads to a fine-tuning problem that is worse than the strong-CP problem the axion was originally invented to solve. We also show that this problem remains unresolved by anthropic selection arguments commonly applied to the high-f{sub a} axion scenario.

  15. Initial Studies into theInitial Studies into the Design of an AxionDesign of an Axion

    E-Print Network [OSTI]

    Gollin, George

    Initial Studies into theInitial Studies into the Design of an AxionDesign of an Axion Cannon. George Gollin #12;History of AxionsHistory of Axions Strong CP Problem in QCDStrong CP Problem in QCD little CP violation observed It also predicts the existence of the axionIt also predicts the existence

  16. New axion and hidden photon constraints from a solar data global fit

    E-Print Network [OSTI]

    Vinyoles, Núria; Villante, Francesco L; Basu, Sarbani; Redondo, Javier; Isern, Jordi

    2015-01-01T23:59:59.000Z

    We present a new statistical analysis that combines helioseismology (sound speed, surface helium and convective radius) and solar neutrino observations (boron and beryllium fluxes) to place upper limits to the properties of non standard weakly interacting particles. Our analysis includes theoretical and observational errors, accounts for tensions between input parameters of solar models and can be easily extended to include other observational constraints. We present two applications to test the method: the well studied case of axions and axion-like particles and the more novel case of low mass hidden photons. For axions we obtain an upper limit at 3 sigma for the axion-photon coupling constant of g_a-gamma solar constraints based on the Standard Solar Models showing the power of our global statistical ap...

  17. Constraints on axion and corrections to Newtonian gravity from the Casimir effect

    E-Print Network [OSTI]

    G. L. Klimchitskaya; V. M. Mostepanenko

    2015-02-26T23:59:59.000Z

    Axion is a light pseudoscalar particle of much interest for physics of elementary particles and for astrophysics. We review the recently obtained constraints on axion to nucleon coupling constants following from different experiments on measuring the Casimir interaction. These constraints are compared with those following from other laboratory experiments within the wide range of masses of axion-like particles from 10^{-10} to 20 eV. We also collect the most strong constraints on the Yukawa-type and power-type corrections to the Newton law of gravitation which follow from measurements of the Casimir interaction, Eotvos- and Cavendish-type experiments. The possibility to obtain stronger constraints on an axion from the Casimir effect is proposed.

  18. Constraints on axion and corrections to Newtonian gravity from the Casimir effect

    E-Print Network [OSTI]

    Klimchitskaya, G L

    2015-01-01T23:59:59.000Z

    Axion is a light pseudoscalar particle of much interest for physics of elementary particles and for astrophysics. We review the recently obtained constraints on axion to nucleon coupling constants following from different experiments on measuring the Casimir interaction. These constraints are compared with those following from other laboratory experiments within the wide range of masses of axion-like particles from 10^{-10} to 20 eV. We also collect the most strong constraints on the Yukawa-type and power-type corrections to the Newton law of gravitation which follow from measurements of the Casimir interaction, Eotvos- and Cavendish-type experiments. The possibility to obtain stronger constraints on an axion from the Casimir effect is proposed.

  19. Axion production and CMB spectral distortion in cosmological tangled magnetic field

    E-Print Network [OSTI]

    Damian Ejlli

    2015-04-01T23:59:59.000Z

    Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both processes to CMB $\\mu$ distortion in the case of resonant photon-axion mixing is studied. Assuming that magnetic field power spectrum is approximated by a power law $P_B(k)\\propto k^n$ with spectral index $n$, it is shown that for magnetic field cut-off scales $172.5$ pc $\\leq \\lambda_B\\leq 4\\times 10^3$ pc, axion contribution to CMB $\\mu$ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using COBE upper limit on $\\mu$ and for magnetic field scale $\\lambda_B\\simeq 415$ pc, weaker limit in comparison with other studies on the magnetic field strength ($B_0\\leq 8.5\\times 10^{-8}$ G) up to a factor 10 for the DFSZ axion model and axion mass $m_a\\geq 2.6\\times 10^{-6}$ eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on $\\mu$ is also presented.

  20. Axion production and CMB spectral distortion in cosmological tangled magnetic field

    E-Print Network [OSTI]

    Ejlli, Damian

    2015-01-01T23:59:59.000Z

    Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both processes to CMB $\\mu$ distortion in the case of resonant photon-axion mixing is studied. Assuming that magnetic field power spectrum is approximated by a power law $P_B(k)\\propto k^n$ with spectral index $n$, it is shown that for magnetic field cut-off scales $172.5$ pc $\\leq \\lambda_B\\leq 4\\times 10^3$ pc, axion contribution to CMB $\\mu$ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using COBE upper limit on $\\mu$ and for magnetic field scale $\\lambda_B\\simeq 415$ pc, weaker limit in comparison with other studies on the magnetic field strength ($B_0\\leq 8.5\\times 10^{-8}$ G) up to a factor 10 for the DFSZ axion model and axion mass $m_a\\geq 2.6\\times 10^{-6}$ eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on...

  1. China Power International New Energy Holding Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here.TelluricPower International New Energy Holding Ltd Place: Shanghai

  2. Towards a new generation axion helioscope

    E-Print Network [OSTI]

    I. G. Irastorza; F. T. Avignone; S. Caspi; J. M. Carmona; T. Dafni; M. Davenport; A. Dudarev; G. Fanourakis; E. Ferrer-Ribas; J. Galan; J. A. Garcia; T. Geralis; I. Giomataris; H. Gomez; D. H. H. Hoffmann; F. J. Iguaz; K. Jakovcic; M. Krcmar; B. Lakic; G. Luzon; M. Pivovaroff; T. Papaevangelou; G. Raffelt; J. Redondo; A. Rodriguez; S. Russenschuck; J. Ruz; I. Shilon; H. Ten Kate; A. Tomas; S. Troitsky; K. van Bibber; J. A. Villar; J. Vogel; L. Walckiers; K. Zioutas

    2011-05-23T23:59:59.000Z

    We study the feasibility of a new generation axion helioscope, the most ambitious and promising detector of solar axions to date. We show that large improvements in magnetic field volume, x-ray focusing optics and detector backgrounds are possible beyond those achieved in the CERN Axion Solar Telescope (CAST). For hadronic models, a sensitivity to the axion-photon coupling of $\\gagamma\\gtrsim {\\rm few} \\times 10^{-12}$ GeV$^{-1}$ is conceivable, 1--1.5 orders of magnitude beyond the CAST sensitivity. If axions also couple to electrons, the Sun produces a larger flux for the same value of the Peccei-Quinn scale, allowing one to probe a broader class of models. Except for the axion dark matter searches, this experiment will be the most sensitive axion search ever, reaching or surpassing the stringent bounds from SN1987A and possibly testing the axion interpretation of anomalous white-dwarf cooling that predicts $m_a$ of a few meV. Beyond axions, this new instrument will probe entirely unexplored ranges of parameters for a large variety of axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics.

  3. Towards a new generation axion helioscope

    SciTech Connect (OSTI)

    Irastorza, I.G.; Carmona, J.M.; Dafni, T., E-mail: Igor.Irastorza@cern.ch, E-mail: titus3@me.com, E-mail: jcarmona@unizar.es [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Zaragoza (Spain); and others

    2011-06-01T23:59:59.000Z

    We study the feasibility of a new generation axion helioscope, the most ambitious and promising detector of solar axions to date. We show that large improvements in magnetic field volume, x-ray focusing optics and detector backgrounds are possible beyond those achieved in the CERN Axion Solar Telescope (CAST). For hadronic models, a sensitivity to the axion-photon coupling of g{sub a?} ?> few × 10{sup ?12} GeV{sup ?1} is conceivable, 1–1.5 orders of magnitude beyond the CAST sensitivity. If axions also couple to electrons, the Sun produces a larger flux for the same value of the Peccei-Quinn scale, allowing one to probe a broader class of models. Except for the axion dark matter searches, this experiment will be the most sensitive axion search ever, reaching or surpassing the stringent bounds from SN1987A and possibly testing the axion interpretation of anomalous white-dwarf cooling that predicts m{sub a} of a few meV. Beyond axions, this new instrument will probe entirely unexplored ranges of parameters for a large variety of axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics.

  4. Fermion measure and axion fields

    E-Print Network [OSTI]

    Mitra, P

    2015-01-01T23:59:59.000Z

    It is known from path integral studies of the chiral anomaly that the fermion measure has to depend on gauge fields interacting with the fermion. It is argued here that in the presence of axion fields interacting with the fermion, they too may be involved in the measure, with unexpected consequences.

  5. Axion results: what is new?

    E-Print Network [OSTI]

    Eduard Masso; Javier Redondo

    2006-09-27T23:59:59.000Z

    The PVLAS collaboration has obtained results that may be interpreted in terms of a light axion-like particle, while the CAST collaboration has not found any signal of such particles. Moreover, the PVLAS results are in gross contradiction with astrophysical bounds. We develop a particle physics model with two paraphotons and with a low energy scale in which these apparent inconsistencies are circumvented.

  6. EDM, Axions, AxionEDM, Axions, Axion--Like ParticlesLike Particles, and, and TheThe Dark SideDark SideTheThe Dark SideDark Side

    E-Print Network [OSTI]

    Pines, Alexander

    EDM, Axions, AxionEDM, Axions, Axion--Like ParticlesLike Particles, and, and TheThe Dark Side EDM · Proposed search for cosmic domains of A i Lik P i lAxion Like Particles 3 CP violation workshop 2013 #12;10-12 · Introduced to solve strong CP problem in QCD: · why is n-EDM so small?y · Axions may

  7. Cosmological constraints on axionic dark radiation from axion-photon conversion in the early Universe

    SciTech Connect (OSTI)

    Higaki, Tetsutaro [Theory Center, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nakayama, Kazunori [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Takahashi, Fuminobu, E-mail: thigaki@post.kek.jp, E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

    2013-09-01T23:59:59.000Z

    Axions seem ubiquitous in string theories and some of them may be produced non-thermally by heavy scalar decays, contributing to dark radiation. We study various cosmological effects of photons produced from the axionic dark radiation through axion-photon conversion in the presence of primordial magnetic fields, and derive tight constraints on the combination of the axion-photon coupling and the primordial magnetic field.

  8. axion solar telescope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    deviations from standard solar models, allowing us to derive new limits on anomalous solar energy losses by the Primakoff emission of axions. For an axion-photon coupling...

  9. New confining force solution of QCD axion domain wall problem

    E-Print Network [OSTI]

    S. M. Barr; Jihn E. Kim

    2014-11-13T23:59:59.000Z

    The serious cosmological problems created by the axion-string/axion-domain-wall system in standard axion models are alleviated by positing the existence of a new confining force. The instantons of this force can generate an axion potential that erases the axion strings long before QCD effects become important, thus preventing QCD-generated axion walls from ever appearing. Axion walls generated by the new confining force would decay so early as not to contribute significantly to the energy in axion dark matter.

  10. Resonantly Enhanced Axion-Photon Regeneration

    E-Print Network [OSTI]

    P. Sikivie; D. B. Tanner; Karl van Bibber

    2007-01-23T23:59:59.000Z

    We point out that photon regeneration-experiments that search for the axion, or axion-like particles, may be resonantly enhanced by employing matched Fabry-Perot optical cavities encompassing both the axion production and conversion magnetic field regions. Compared to a simple photon regeneration experiment, which uses the laser in a single-pass geometry, this technique can result in a gain in rate of order ${\\cal F}^2$, where ${\\cal F}$ is the finesse of the cavities. This gain could feasibly be $10^{(10-12)}$, corresponding to an improvement in sensitivity in the axion-photon coupling, $g_{a\\gamma\\gamma}$ , of order ${\\cal F}^{1/2} \\sim 10^{(2.5-3)}$, permitting a practical purely laboratory search to probe axion-photon couplings not previously excluded by stellar evolution limits, or solar axion searches.

  11. Guidelines for axion identification in astrophysical observations

    E-Print Network [OSTI]

    K. Zioutas; Y. Semertzidis; Th. Papaevangelou

    2005-12-21T23:59:59.000Z

    The origin of various celestial phenomena have remained mysterious for conventional astrophysics. Therefore, alternative solutions should be considered, taking into account the involvement of unstable dark-matter particle candidates, such as the celebrated axions or other as yet unforeseen axion-like particles. Their spontaneous and induced decay by the ubiquitous solar magnetic fields can be at the origin of persisting enigmatic X-ray emission, giving rise to a steady and a transient/local solar activity, respectively. The (coherent) conversion of photons into axion(-like) particles in intrinsic magnetic fields may modify the solar axion spectrum. The reversed process can be behind transient (solar) luminosity deficits in the visible. Then, the Sun might be also a strong source of ~eV-axions. Thus, enigmatic observations might be the as yet missing direct signature for axion(-like) particles in earth-bound detectors.

  12. Non-linear hydrodynamics of axion dark matter: relative velocity effects and "quantum forces"

    E-Print Network [OSTI]

    Marsh, David J E

    2015-01-01T23:59:59.000Z

    The non-linear hydrodynamic equations for axion/scalar field dark matter (DM) in the non-relativistic Madelung-Shcr\\"{o}dinger form are derived in a simple manner, including the effects of universal expansion and Hubble drag. The hydrodynamic equations are used to investigate the relative velocity between axion DM and baryons, and the moving-background perturbation theory (MBPT) derived. Axions massive enough to be all of the DM do not affect the coherence length of the relative velocity, but the MBPT equations are modified by the inclusion of the axion effective sound speed. These MBPT equations are necessary for accurately modelling the effects of axion DM on the formation of the first cosmic structures, and suggest that the 21cm power spectrum could improve constraints on axion mass by up to four orders of magnitude with respect to the current best constraints. A further application of these results uses the "quantum force" analogy to model scalar field gradient energy in a smoothed-particle hydrodynamics ...

  13. Power and efficiency limits for internal combustion engines via methods of finite-time thermodynamics

    E-Print Network [OSTI]

    Berry, R. Stephen

    Power and efficiency limits for internal combustion engines via methods of finite publication 17 June 1993) Analytical expressionsfor the upper bounds of power and efficiency of an internal and expensiveto compute and analyze.2If we are interestedin maximum power output or in maximum effi- ciency

  14. International Conference of the Centennial Anniversary of the Purchasing Power of Money by Irving Fisher

    E-Print Network [OSTI]

    Boyer, Edmond

    International Conference of the Centennial Anniversary of the Purchasing Power of Money monétaires en économie ouverte. When French economists read The Purchasing Power of Money "International Conference of the Centennial Anniversary of the Purchasing Power of Money by Irving Fisher, Lyon

  15. Search for Axions with the CDMS Experiment

    SciTech Connect (OSTI)

    Ahmed, Z.; /Caltech; Akerib, D.S.; /Case Western Reserve U.; Arrenberg, S.; /Zurich U.; Bailey, C.N.; /Case Western Reserve U.; Balakishiyeva, D.; /Florida U.; Baudis, L.; /Zurich U.; Bauer, D.A.; /Fermilab; Beaty, J.; /Minnesota U.; Brink, P.L.; /Stanford U., Phys. Dept.; Bruch, T.; /Zurich U.; Bunker, R.; /UC, Santa Barbara /Stanford U., Phys. Dept.

    2009-02-01T23:59:59.000Z

    We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local Galactic axion conversion into electrons in the germanium crystal detectors. The solar axion search sets an upper limit on the Primakov coupling g{sub a{gamma}{gamma}} of 2.4 x 10{sup ?9} GeV{sup -1} at the 95% confidence level for an axion mass less than 0.1 keV/c{sup 2}. This limit benefits from the first precise measurement of the absolute crystal plane orientations in this type of experiment. The Galactic axion search analysis sets a world-leading experimental upper limit on the axio-electric coupling g{sub a{bar e}e} of 1.4 x 10{sup -12} at the 90% confidence level for an axion mass of 2.5 keV/c{sup 2}. This analysis excludes an interpretation of the DAMA annual modulation result in terms of Galactic axion interactions for axion masses above 1.4 keV/c{sup 2}.

  16. Axion physics in a Josephson junction environment

    E-Print Network [OSTI]

    Christian Beck

    2011-11-23T23:59:59.000Z

    We show that recent experiments based on Josephson junctions, SQUIDS, and coupled Josephson qubits have a cosmological interpretation in terms of axionic dark matter physics, in the sense that they allow for analogue simulation of early-universe axion physics. We propose new experimental setups in which SQUID-like axionic interactions in a resonant Josephson junction environment can be tested, similar in nature to recent experiments that test for quantum entanglement of two coupled Josephson qubits. We point out that the parameter values relevant for early-universe axion cosmology are accessible with present day's achievements in nanotechnology.

  17. axions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    far exceeds the conventional cosmological bound. Such theories have several dark matter candidates. David B. Kaplan; Kathryn M. Zurek 2005-07-29 4 QCD axion and...

  18. Axion inflation with gauge field production and primordial black holes

    E-Print Network [OSTI]

    Edgar Bugaev; Peter Klimai

    2014-10-19T23:59:59.000Z

    We study the process of primordial black hole (PBH) formation at the beginning of radiation era for the cosmological scenario in which the inflaton is a pseudo-Nambu-Goldstone boson (axion) and there is a coupling of the inflaton with some gauge field. In this model inflation is accompanied by the gauge quanta production and a strong rise of the curvature power spectrum amplitude at small scales (along with non-Gaussianity) is predicted. We show that data on PBH searches can be used for a derivation of essential constraints on the model parameters in such an axion inflation scenario. We compare our numerical results with the similar results published earlier, in the work by Linde et al.

  19. Oscillations in the CMB from Axion Monodromy Inflation

    SciTech Connect (OSTI)

    Flauger, Raphael; /Texas U.; McAllister, Liam; Pajer, Enrico; /Cornell U., Phys. Dept.; Westphal, Alexander; /SLAC /Stanford U., Phys. Dept.; Xu, Gang; /Cornell U., Phys. Dept.

    2011-12-01T23:59:59.000Z

    We study the CMB observables in axion monodromy inflation. These well-motivated scenarios for inflation in string theory have monomial potentials over super-Planckian field ranges, with superimposed sinusoidal modulations from instanton effects. Such periodic modulations of the potential can drive resonant enhancements of the correlation functions of cosmological perturbations, with characteristic modulations of the amplitude as a function of wavenumber. We give an analytical result for the scalar power spectrum in this class of models, and we determine the limits that present data places on the amplitude and frequency of modulations. Then, incorporating an improved understanding of the realization of axion monodromy inflation in string theory, we perform a careful study of microphysical constraints in this scenario. We find that detectable modulations of the scalar power spectrum are commonplace in well-controlled examples, while resonant contributions to the bispectrum are undetectable in some classes of examples and detectable in others. We conclude that resonant contributions to the spectrum and bispectrum are a characteristic signature of axion monodromy inflation that, in favorable cases, could be detected in near-future experiments.

  20. Oscillations in the CMB from axion monodromy inflation

    SciTech Connect (OSTI)

    Flauger, Raphael [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); McAllister, Liam; Pajer, Enrico; Xu, Gang [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Westphal, Alexander, E-mail: raphael.flauger@yale.edu, E-mail: mcallister@cornell.edu, E-mail: ep295@cornell.edu, E-mail: awestpha@stanford.edu, E-mail: gx26@cornell.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2010-06-01T23:59:59.000Z

    We study the CMB observables in axion monodromy inflation. These well-motivated scenarios for inflation in string theory have monomial potentials over super-Planckian field ranges, with superimposed sinusoidal modulations from instanton effects. Such periodic modulations of the potential can drive resonant enhancements of the correlation functions of cosmological perturbations, with characteristic modulations of the amplitude as a function of wavenumber. We give an analytical result for the scalar power spectrum in this class of models, and we determine the limits that present data places on the amplitude and frequency of modulations. Then, incorporating an improved understanding of the realization of axion monodromy inflation in string theory, we perform a careful study of microphysical constraints in this scenario. We find that detectable modulations of the scalar power spectrum are commonplace in well-controlled examples, while resonant contributions to the bispectrum are undetectable in some classes of examples and detectable in others. We conclude that resonant contributions to the spectrum and bispectrum are a characteristic signature of axion monodromy inflation that, in favorable cases, could be detected in near-future experiments.

  1. Prospects for the CERN Axion Solar Telescope Sensitivity to 14.4 keV Axions

    E-Print Network [OSTI]

    Kresimir Jakovcic; for the CAST Collaboration

    2006-11-15T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) is searching for solar axions using the 9.0 T strong and 9.26 m long transverse magnetic field of a twin aperture LHC test magnet, where axions could be converted into X-rays via reverse Primakoff process. Here we explore the potential of CAST to search for 14.4 keV axions that could be emitted from the Sun in M1 nuclear transition between the first, thermally excited state, and the ground state of 57Fe nuclide. Calculations of the expected signals, with respect to the axion-photon coupling, axion-nucleon coupling and axion mass, are presented in comparison with the experimental sensitivity.

  2. Fast Radio Bursts from Axion Stars

    E-Print Network [OSTI]

    Aiichi Iwazaki

    2015-04-20T23:59:59.000Z

    Axions are one of the most promising candidates of dark matter. The axions have been shown to form miniclusters with masses $\\sim 10^{-12}M_{\\odot}$, some of which condense to form axion stars. We have recently shown a possible origin of fast radio bursts ( FRBs ) by assuming that the axion stars are main component of halos: FRBs arise from the collisions between the axion stars and neutron stars. It is remarkable that the masses of the axion stars obtained by the comparison of the theoretical and observational event rates are coincident with the mass $\\sim 10^{-12}M_{\\odot}$. In this paper, we describe our model of FRBs in detail. We derive the approximate solutions of the axion stars with large radii and constraint their masses for the approximation to be valid. The FRBs are emitted from the atmospheres of neutron stars in the collisions. By calculating the optical depth of the atmospheres, we show that they are transparent for the radiations with the frequency given by the axion mass $m_a$ such as $m_a/2\\pi\\simeq 2.4$GHz$(m_a/10^{-5}\\rm eV)$. Although the radiations are linearly polarized when they are emitted, they are shown to be circularly polarized after they pass magnetospheres of neutron stars. We also show that the frequencies of the FRBs have finite bandwidths owing to the Doppler effect when the neutron stars pass through the axion stars. The presence of the finite bandwidths is a distinctive feature of our model and can be tested observationally. Furthermore, we show that similar FRBs may arise when the axion stars collide with magnetic white dwarfs. The characteristic feature is that the durations of the bursts are of the order of $0.1$second and they are monochromatic contrary to the FRBs observed. We can determine the axion mass by the observating both of the their frequencies and red shifts $z$.

  3. Dark Matter Related to Axion and Axino

    E-Print Network [OSTI]

    Jihn E. Kim

    2008-10-30T23:59:59.000Z

    I discuss the essential features of the QCD axion: the strong CP solution and hence its theoretical necessity. I also review the axion and axino effects on astrophysics and cosmology, in particular with emphasis on their role in the dark matter component in the universe.

  4. Searches for Astrophysical and Cosmological Axions

    SciTech Connect (OSTI)

    Asztalos, S J; Rosenberg, L J; van Bibber, K; Sikivie, P; Zioutas, K

    2006-05-03T23:59:59.000Z

    The axion remains, after nearly 30 years, the most compelling and elegant solution to the strong-CP problem, i.e. why this symmetry is protected in QCD in spite of CP violation elsewhere. The axion is expected to be extremely light, and possess extraordinarily feeble couplings to matter and radiation. Because of its small couplings, the axion has defied experimental confirmation and is unlikely to be discovered in conventional laboratory experiments (i.e. production-detection). Nevertheless, a sufficiently light axion would have been produced abundantly in the Big Bang and is an excellent candidate for the dark matter of the Universe. Through the axion's two-photon coupling, implying axion-photon mixing in an external electromagnetic field, galactic halo axions may be feasibly detected by their resonant conversion to RF photons in a microwave cavity permeated by magnetic field with current technology. Over the past decade experiments have already set interesting limits in mass and coupling; upgrades in progress to photon detection schemes at or below the standard quantum limit will soon enable definitive searches. Similarly, axions produced in the solar burning core might be detectable by their conversion to x-rays in a magnetic helioscope. Indeed current published limits already equal the best bounds on axion-photon coupling inferred from the concordance of stellar evolution models and observations, from horizontal branch stars. Significant improvements in both the mass range and sensitivity of the axion helioscope technique will be forthcoming in the next few years. This report will first summarize the theoretical background of the axion, and laboratory, astrophysical and cosmological limits on its mass and couplings. Cavity microwave searches for cosmic axions will then be reviewed, focusing on the current large-scale experiments (ADMX in the US; CARRACK in Japan), and their enabling technologies (HFET and SQUID amplifiers; Rydberg-atom single-quantum detection). Last, the searches for solar axions will be discussed, with particular attention to the CAST experiment at CERN. The conclusion provides a basis for cautious optimism that a definitive verdict on the axion, or at least its role as a dark matter component, could be expected within a decade.

  5. Solar axion search with the CAST experiment

    E-Print Network [OSTI]

    CAST Collaboration; E. Arik; S. Aune; D. Autiero; K. Barth; A. Belov; B. Beltrán; S. Borghi; F. S. Boydag; H. Bräuninger; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; T. Dafni; M. Davenport; L. Di Lella; O. B. Dogan; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; H. Fischer; J. Franz; J. Galán; E. Gazis; T. Geralis; I. Giomataris; S. Gninenko; H. Gómez; M. Hasinoff; F. H. Heinsius; I. Hikmet; D. H. H. Hoffmann; I. G. Irastorza; J. Jacoby; K. Jakov?i?; D. Kang; T. Karageorgopoulou; M. Karuza; K. Königsmann; R. Kotthaus; M. Kr?mar; K. Kousouris; M. Kuster; B. Laki?; C. Lasseur; A. Liolios; A. Ljubi?i?; V. Lozza; G. Lutz; G. Luzón; D. Miller; J. Morales; T. Niinikoski; A. Nordt; A. Ortiz; T. Papaevangelou; M. J. Pivovaroff; A. Placci; G. Raiteri; G. Raffelt; H. Riege; A. Rodríguez; J. Ruz; I. Savvidis; Y. Semertzidis; P. Serpico; S. K. Solanki; R. Soufli; L. Stewart; M. Tsagri; K. van Bibber; J5D. Villar; J. Vogel; L. Walckiers; K. Zioutas

    2008-10-10T23:59:59.000Z

    The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipe of an LHC dipole. The analysis of the data recorded during the first phase of the experiment with vacuum in the magnet pipes has resulted in the most restrictive experimental limit on the coupling constant of axions to photons. In the second phase, CAST is operating with a buffer gas inside the magnet pipes in order to extent the sensitivity of the experiment to higher axion masses. We will present the first results on the $^{4}{\\rm He}$ data taking as well as the system upgrades that have been operated in the last year in order to adapt the experiment for the $^{3}{\\rm He}$ data taking. Expected sensitivities on the coupling constant of axions to photons will be given for the recent $^{3}{\\rm He}$ run just started in March 2008.

  6. Continuous Axion Photon Duality and its Consequences

    E-Print Network [OSTI]

    E. I. Guendelman

    2007-11-23T23:59:59.000Z

    The axion photon system in an external magnetic field, when for example considered with the geometry of the experiments exploring axion photon mixing, displays a continuous axion-photon duality symmetry in the limit the axion mass is neglected. The conservation law that follows from this symmetry is obtained. The magnetic field interaction is seen to be equivalent to first order to the interaction of a complex charged field with an external electric potential, where this ficticious "electric potential" is proportional to the external magnetic field. This allows to solve for the scattering amplitudes using already known scalar QED results. It is argued that in more generic conditions (not just related to these experiments) axion-photon condensation could be obtained for high magnetic fields. Finally an exact constraint originating fromthe current conservation on the amplitudes of reflected and transmited waves is obtained.

  7. Axion constraints in nonstandard thermal histories

    SciTech Connect (OSTI)

    Grin, Daniel; Smith, Tristan L.; Kamionkowski, Marc [California Institute of Technology, Mail Code 130-33, Pasadena, California 91125 (United States)

    2008-04-15T23:59:59.000Z

    It is usually assumed that dark matter is produced during the radiation-dominated era. There is, however, no direct evidence for radiation domination prior to big-bang nucleosynthesis. Two nonstandard thermal histories are considered. In one, the low-temperature-reheating scenario, radiation domination begins as late as {approx}1 MeV, and is preceded by significant entropy generation. Thermal axion relic abundances are then suppressed, and cosmological limits to axions are loosened. For reheating temperatures T{sub rh} < or approx. 35 MeV, the large-scale structure limit to the axion mass is lifted. The remaining constraint from the total density of matter is significantly relaxed. Constraints are also relaxed for higher reheating temperatures. In a kination scenario, a more modest change to cosmological axion constraints is obtained. Future possible constraints to axions and low-temperature reheating from the helium abundance and next-generation large-scale-structure surveys are discussed.

  8. Resonantly Enhanced Axion-Photon Regeneration

    SciTech Connect (OSTI)

    Sikivie, P. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Theoretical Physics Division, CERN, CH-1211 Geneva 23 (Switzerland); Tanner, D. B. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Bibber, Karl van [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2007-04-27T23:59:59.000Z

    Photon-regeneration experiments which search for the axion, or axionlike particles, may be resonantly enhanced by employing matched Fabry-Perot optical cavities encompassing both the axion production and conversion magnetic field regions. Compared to a simple photon-regeneration experiment, which uses the laser in a single-pass geometry, this technique can result in a gain in rate of order F{sup 2}, where F is the finesse of the cavities. This gain could feasibly be 10{sup (10-12)}, corresponding to an improvement in sensitivity in the axion-photon coupling g{sub a{gamma}}{sub {gamma}} of order F{sup 1/2}{approx}10{sup (2.5-3)}, permitting a practical purely laboratory search to probe axion-photon couplings not previously excluded by stellar evolution limits or solar axion searches.

  9. Constraints on the axion-electron coupling for solar axions produced by Compton process and bremsstrahlung

    E-Print Network [OSTI]

    A. V. Derbin; A. S. Kayunov; V. N. Muratova; D. A. Semenov; E. V. Unzhakov

    2011-01-12T23:59:59.000Z

    The search for solar axions produced by Compton ($\\gamma+e^-\\rightarrow e^-+A$) and bremsstrahlung-like ($e^-+Z \\rightarrow Z+e^-+A$) processes has been performed. The axion flux in the both cases depends on the axion-electron coupling constant. The resonant excitation of low-lying nuclear level of $^{169}\\rm{Tm}$ was looked for: $A+^{169}$Tm $\\rightarrow ^{169}$Tm$^*$ $\\rightarrow ^{169}$Tm $+ \\gamma$ (8.41 keV). The Si(Li) detector and $^{169}$Tm target installed inside the low-background setup were used to detect 8.41 keV $\\gamma$-rays. As a result, a new model independent restriction on the axion-electron and the axion-nucleon couplings was obtained: $g_{Ae}\\times|g^0_{AN}+ g^3_{AN}|\\leq 2.1\\times10^{-14}$. In model of hadronic axion this restriction corresponds to the upper limit on the axion-electron coupling and on the axion mass $g_{Ae}\\times m_A\\leq3.1\\times10^{-7}$ eV (90% c.l.). The limits on axion mass are $m_A\\leq$ 105 eV and $m_A\\leq$ 1.3 keV for DFSZ- and KSVZ-axion models, correspondingly (90% c.l.).

  10. Extended axion electrodynamics: Optical activity induced by nonstationary dark matter

    E-Print Network [OSTI]

    A. B. Balakin; N. O. Tarasova

    2012-01-14T23:59:59.000Z

    We establish a new self-consistent Einstein-Maxwell-axion model based on the Lagrangian, which is linear in the pseudoscalar (axion) field and its four-gradient and includes the four-vector of macroscopic velocity of the axion system as a whole. We consider extended equations of the axion electrodynamics, modified gravity field equations, and discuss nonstationary effects in the phenomenon of optical activity induced by axions.

  11. Quark mass uncertainties revive Kim-Shifman-Vainshtein-Zakharov axion dark matter

    E-Print Network [OSTI]

    Buckley, Matthew R.; Murayama, Hitoshi

    2007-01-01T23:59:59.000Z

    mass uncertainties revive KSVZ axion dark matter Matthew R.bounds on the QCD axion, speci?cally KSVZ axions in the 2 ?particles. The as-yet-unseen axion, origi- nally proposed to

  12. Operating Reserves and Wind Power Integration: An International Comparison; Preprint

    SciTech Connect (OSTI)

    Milligan, M.; Donohoo, P.; Lew, D.; Ela, E.; Kirby, B.; Holttinen, H.; Lannoye, E.; Flynn, D.; O'Malley, M.; Miller, N.; Eriksen, P. B.; Gottig, A.; Rawn, B.; Gibescu, M.; Lazaro, E. G.; Robitaille, A.; Kamwa, I.

    2010-10-01T23:59:59.000Z

    This paper provides a high-level international comparison of methods and key results from both operating practice and integration analysis, based on an informal International Energy Agency Task 25: Large-scale Wind Integration.

  13. Axion mass estimates from resonant Josephson junctions

    E-Print Network [OSTI]

    Christian Beck

    2014-06-10T23:59:59.000Z

    Recently it has been proposed that dark matter axions from the galactic halo can produce a small Shapiro step-like signal in Josephson junctions whose Josephson frequency resonates with the axion mass [C. Beck, PRL 111, 231801 (2013)]. Here we show that the axion field equations in a voltage-driven Josephson junction environment allow for a nontrivial solution where the axion-induced electric current manifests itself as an oscillating supercurrent. The linear change of phase associated with this nontrivial solution implies the formal existence of a large magnetic field in a tiny surface area of the weak link region of the junction which makes incoming axions decay into microwave photons. We derive a condition for the design of Josephson junction experiments so that they can act as optimum axion detectors. Four independent recent experiments are discussed in this context. The observed Shapiro step anomalies of all four experiments consistently point towards an axion mass of $(110 \\pm 2)\\mu $eV. This mass value is compatible with the recent BICEP2 results and implies that Peccei-Quinn symmetry breaking was taking place after inflation.

  14. Large Field Inflation from Axion Mixing

    E-Print Network [OSTI]

    Shiu, Gary; Ye, Fang

    2015-01-01T23:59:59.000Z

    We study the general multi-axion systems, focusing on the possibility of large field inflation driven by axions. We find that through axion mixing from a non-diagonal metric on the moduli space and/or from St\\"uckelberg coupling to a U(1) gauge field, an effectively super-Planckian decay constant can be generated without the need of "alignment" in the axion decay constants. We also investigate the consistency conditions related to the gauge symmetries in the multi-axion systems, such as vanishing gauge anomalies and the potential presence of generalized Chern-Simons terms. Our scenario applies generally to field theory models whose axion periodicities are intrinsically sub-Planckian, but it is most naturally realized in string theory. The types of axion mixings invoked in our scenario appear quite commonly in D-brane models, and we present its implementation in type II superstring theory. Explicit stringy models exhibiting all the characteristics of our ideas are constructed within the frameworks of Type IIA ...

  15. Axionic shortcuts for high energy photons

    SciTech Connect (OSTI)

    Nicolaidis, A., E-mail: nicolaid@auth.gr [Theoretical Physics Department, University of Thessaloniki, 54124 Thessaloniki (Greece)

    2010-04-01T23:59:59.000Z

    We study the photon axion mixing in the presence of large extra dimensions. The eigenvalues and eigenstates of the mixing matrix are analyzed and we establish the resonance condition for the total conversion of a high energy photon into a Kaluza-Klein (KK) axion state. This resonant transition, a photon transformed into a KK axion traveling freely through the bulk and converting back into a photon, may provide a plausible explanation for the transparency of the universe to energetic photons. If the brane we live in is curved, then there are shortcuts through the bulk, which the axion can take. Within our model, the photons having the appropriate resonance energy are using the axionic shortcut and arrive earlier compared to the photons which follow the geodesic on the brane. We suggest that such axionic shortcuts are at the root of the dispersion of time arrival of photons observed by the MAGIC telescope. We indicate also the cosmological significance of the existence of axionic shortcuts for the photon.

  16. Search for Axions with the CDMS Experiment

    SciTech Connect (OSTI)

    Ahmed, Z.; Golwala, S. R.; Moore, D.; Wang, G. [Department of Physics, California Institute of Technology, Pasadena, California 91125 (United States); Akerib, D. S.; Bailey, C. N.; Dragowsky, M. R.; Grant, D. R.; Hennings-Yeomans, R. [Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Arrenberg, S.; Baudis, L.; Bruch, T.; Tarka, M. [Physics Institute, University of Zuerich, Zuerich (Switzerland); Balakishiyeva, D.; Saab, T. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Bauer, D. A.; DeJongh, F.; Hall, J.; Holmgren, D.; Hsu, L. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

    2009-10-02T23:59:59.000Z

    We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local galactic axion conversion into electrons in the germanium crystal detectors. The solar axion search sets an upper limit on the Primakov coupling g{sub ag}amma{sub {gamma}} of 2.4x10{sup -9} GeV{sup -1} at the 95% confidence level for an axion mass less than 0.1 keV/c{sup 2}. This limit benefits from the first precise measurement of the absolute crystal plane orientations in this type of experiment. The galactic axion search analysis sets a world-leading experimental upper limit on the axioelectric coupling g{sub aee} of 1.4x10{sup -12} at the 90% confidence level for an axion mass of 2.5 keV/c{sup 2}.

  17. CAST: An Inspiring Axion Helioscope ala Sikivie

    SciTech Connect (OSTI)

    Zioutas, K.; Anastassopoulos, V. [University of Patras, Patras (Greece); Tsagri, M. [University of Patras, Patras (Greece); CERN, 1211 Geneve 23 (Switzerland); Semertzidis, Y. [Brookhaven National Laboratory, Upton, NY (United States); Papaevangelou, T. [IRFU, Centre d'Etudes Nucleaires de Saclay, Gif-sur-Yvette (France)

    2010-08-30T23:59:59.000Z

    CAST is a data taking axion helioscope using a recycled LHC test magnet, CERN's detector technology and cryogenics expertise. An imaging X-ray telescope improves substantially the detection sensitivity and axion-ID. Massive axion-like particles of the Kaluza-Klein type were first introduced to explain the paradox of the hot corona, which is even hotter at locations overlying magnetic spots. This is suggesting that the CAST detection principle might be at work there, but being somehow modified and performing better. Remarkably, the density profile of the Sun allows for resonance crossing (m{sub axion}c{sup 2{approx_equal}}h{omega}{sub plasma}), which axion helioscopes are aiming to reach. The restless Sun favours this occasionally even further. Then, such processes can give rise to a chimera of converted axions or the like, making the Sun appear, within known physics, as mysterious and unpredictable as it is. CAST axion limits were used to conclude also for the hidden sector paraphotons. This is then suggestive for novel helioscopes for exotica like paraphotons, chameleons, etc. Pierre Sikivie's pioneering idea was to use a magnetic field as a catalyst to transform particles from the dark sector to ours, and vice versa.

  18. Axion hot dark matter bounds

    E-Print Network [OSTI]

    G. Raffelt; S. Hannestad; A. Mirizzi; Y. Y. Y. Wong

    2008-08-06T23:59:59.000Z

    We derive cosmological limits on two-component hot dark matter consisting of neutrinos and axions. We restrict the large-scale structure data to the safely linear regime, excluding the Lyman-alpha forest. We derive Bayesian credible regions in the two-parameter space consisting of m_a and sum(m_nu). Marginalizing over sum(m_nu) provides m_aaxions the same data and methods give sum(m_nu)< 0.63 eV (95% CL).

  19. A Model of Visible QCD Axion

    E-Print Network [OSTI]

    Fukuda, Hajime; Ibe, Masahiro; Yanagida, Tsutomu T

    2015-01-01T23:59:59.000Z

    We pursue a class of visible axion models where the axion mass is enhanced by strong dynamics in a mirrored copy of the Standard Model in the line of the idea put forward by Rubakov. In particular, we examine the consistency of the models with laboratory, astrophysical, and cosmological constraints. As a result, viable parameter regions are found, where the mass of the axion is of $O(100)$ MeV or above while the Peccei-Quinn breaking scale is at around $10^{3\\mbox{-}5}$ GeV.

  20. A Model of Visible QCD Axion

    E-Print Network [OSTI]

    Hajime Fukuda; Keisuke Harigaya; Masahiro Ibe; Tsutomu T. Yanagida

    2015-05-07T23:59:59.000Z

    We pursue a class of visible axion models where the axion mass is enhanced by strong dynamics in a mirrored copy of the Standard Model in the line of the idea put forward by Rubakov. In particular, we examine the consistency of the models with laboratory, astrophysical, and cosmological constraints. As a result, viable parameter regions are found, where the mass of the axion is of $O(100)$ MeV or above while the Peccei-Quinn breaking scale is at around $10^{3\\mbox{-}5}$ GeV.

  1. Axion Induced Oscillating Electric Dipole Moments

    E-Print Network [OSTI]

    Hill, Christopher T

    2015-01-01T23:59:59.000Z

    The axion electromagnetic anomaly induces an oscillating electric dipole for any static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency $m_a$ and strength $\\sim 10^{-32}$ e-cm, two orders of magnitude above the nucleon, and within four orders of magnitude of the present standard model DC limit. This may suggest sensitive new experimental venues for the axion dark matter search.

  2. Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches

    E-Print Network [OSTI]

    F. J. Iguaz; S. Aune; F. Aznar; J. F. Castel; T. Dafni; M. Davenport; E. Ferrer-Ribas; J. Galan; J. A. Garcia; J. G. Garza; I. Giomataris; I. G. Irastorza; T. Papaevangelou; A. Rodriguez; A. Tomas; T. Vafeiadis; S. C. Yildiz

    2015-01-07T23:59:59.000Z

    Axion helioscopes search for solar axions by their conversion in x-rays in the presence of high magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. In this work, we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The actual setup in CAST has achieved background levels below 10$^{-6}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$, a factor 100 lower than the first generation of Micromegas detectors. This reduction is based on active and passive shielding techniques, the selection of radiopure materials, offline discrimination techniques and the high granularity of the readout. We describe in detail the background model of the detector, based on its operation at CAST site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4 simulations. The best levels currently achieved at LSC are low than 10$^{-7}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$ and show good prospects for the application of this technology in IAXO. Finally, we present some ideas and results for reducing the energy threshold of these detectors below 1 keV, using high-transparent windows, autotrigger electronics and studying the cluster shape at different energies. As a high flux of axion-like-particles is expected in this energy range, a sub-keV threshold detector could enlarge the physics case of axion helioscopes.

  3. Thermodynamics of non-local materials: extra fluxes and internal powers

    E-Print Network [OSTI]

    Mauro Fabrizio; Barbara Lazzari; Roberta Nibbi

    2011-04-15T23:59:59.000Z

    The most usual formulation of the Laws of Thermodynamics turns out to be suitable for local or simple materials, while for non-local systems there are two different ways: either modify this usual formulation by introducing suitable extra fluxes or express the Laws of Thermodynamics in terms of internal powers directly, as we propose in this paper. The first choice is subject to the criticism that the vector fluxes must be introduced a posteriori in order to obtain the compatibility with the Laws of Thermodynamics. On the contrary, the formulation in terms of internal powers is more general, because it is a priori defined on the basis of the constitutive equations. Besides it allows to highlight, without ambiguity, the contribution of the internal powers in the variation of the thermodynamic potentials. Finally, in this paper, we consider some examples of non-local materials and derive the proper expressions of their internal powers from the power balance laws.

  4. Thermal production of axions in the Earth

    SciTech Connect (OSTI)

    Davoudiasl, Hooman; Huber, Patrick [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Department of Physics, IPNAS, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2009-05-01T23:59:59.000Z

    We estimate the production rate of axion-type particles in the core of the Earth, at a temperature T{approx_equal}5000 K. We constrain thermal geo-axion emission by demanding a core-cooling rate less than O(100) K/Gyr, as suggested by geophysics. This yields a 'nonstellar' (unaffected by extreme stellar temperatures or densities) bound on the axion-electron (ae) fine structure constant, {alpha}{sub ae} < or approx. 10{sup -18}, stronger than the existing accelerator (vacuum) bound by 4 orders of magnitude. We consider the prospects for measuring the geo-axion flux through conversion into photons in a geoscope; such measurements can further constrain {alpha}{sub ae}.

  5. Axions from cosmic string and wall decay

    SciTech Connect (OSTI)

    Hagmann, C A

    2010-03-10T23:59:59.000Z

    If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.

  6. Axions from cosmic string and wall decay

    SciTech Connect (OSTI)

    Hagmann, Chris [Lawrence Livermore National Laboratory, L-59, 7000 East Ave, Livermore, CA (United States)

    2010-08-30T23:59:59.000Z

    If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall{approx}}1-100(f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.

  7. 24 DTU International Energy Report 2013 Stochastic power generation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    that their power output can be curtailed if necessary. Renewable energy sources such as wind, solar, wave and tidal are not dispatchable. Indeed, wind farms and solar power plants can be scheduled and controlled only to the extent of energy storage, which can compen- sate for the limited predictability of wind and solar power. Changing

  8. Remarks on Axion-like models

    E-Print Network [OSTI]

    Patricio Gaete; Iván Schmidt

    2006-12-29T23:59:59.000Z

    For a recently proposed alternative to the traditional axion model, we study its long distance behavior, in particular the confinement versus screening issue, and show that a compactified version of this theory can be further mapped into the massive Schwinger model. Our calculation is based on the gauge-invariant but path-dependent variables formalism. This result agrees qualitatively with the usual axion model.

  9. Update of axion CDM energy density

    SciTech Connect (OSTI)

    Huh, Ji-Haeng [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2008-11-23T23:59:59.000Z

    We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale {lambda}{sub QCD}, the current quark masses m{sub q}'s and the Peccei-Quinn scale F{sub a}, including firstly introduced 1.85 factor which is from the initial overshoot.

  10. Phenomenological Implications of Heavy Axion Models

    SciTech Connect (OSTI)

    Giannotti, M.; Nita, R.; Welch, E. [Physical Sciences, Barry University, FL 33161, Miami Shores (United States)

    2010-08-30T23:59:59.000Z

    Several models predict the existence of heavy (mass{approx}MeV or so) pseudoscalar (axion-like) particles. This possibility is permitted only if the relation between the axion mass and the Peccei-Quinn constant is relaxed.Here we consider a possible phenomenological consequence of these models. After being produced in the supernova core, these heavy axions would escape and a fraction of them would decay into photons before reaching the earth. We calculated the expected spectrum of these photons from the supernovae SN1987A and CAS A, in terms of the axion mass and the Peccei-Quinn constant f{sub a}, and compared our results to the data from the FERMI Large Area Telescope. The analysis provides strong constraints on the allowed region in the axion parameter space for 100 keV < or approx. m{sub a} < or approx. 1 GeV. This mass region is completely excluded unless f{sub a}>10{sup 112} GeV. For axion masses {approx}100 MeV, the constraint is stronger f{sub a}> a few 10{sup 14} GeV.

  11. Topology in QCD and the axion abundance

    E-Print Network [OSTI]

    Kitano, Ryuichiro

    2015-01-01T23:59:59.000Z

    The temperature dependence of the topological susceptibility (chi_t) in QCD essentially determines the abundance of the QCD axion in the Universe, and is commonly estimated, based on the instanton picture, to be a certain negative power of temperature. While lattice QCD should be able to check the instanton picture in principle, the region of the temperature where lattice calculations of chi_t are reliable is rather limited in practice, because existing methods on the lattice will probably fail when chi_t decreases rapidly with temperatures. In this work, two exploratory studies are presented. First, to realize the limitation of temperature we perform lattice calculations of chi_t in the quenched approximation and find that it becomes difficult with a given resource when T > 2 T_c. A possible way out is proposed and some test calculations are given. The absolute value and the temperature dependence of chi_t in real QCD can be significantly different from that in the quenched approximation, and is not well est...

  12. Market power in international carbon emissions trading: a laboratory test

    E-Print Network [OSTI]

    Carlén, Björn.

    The prospect that governments of one or a few large countries, or trading blocs, would engage in international greenhouse gas emissions trading has led several policy analysts to express concerns that trade would be ...

  13. A review on axions and the strong CP problem

    SciTech Connect (OSTI)

    Kim, Jihn E. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2010-02-10T23:59:59.000Z

    We review the recent developments on axion physics. Some new comments on the strong CP problem, the axion mass, and the simple energy loss mechanism of white dwarfs and related issues are included.

  14. Axion as a fundamental entity in the Universe

    SciTech Connect (OSTI)

    Kim, Jihn E. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2010-08-30T23:59:59.000Z

    I comment on Sikivie's remarkable achievements in particle physics and cosmology which include the introduction of the E{sub 6} grand unification idea, axions as cold dark matter components, and axion search experiments.

  15. 1st International Workshop on High Performance Computing, Networking and Analytics for the Power Grid

    E-Print Network [OSTI]

    1st International Workshop on High Performance Computing, Networking and Analytics for the Power Transient Stability" #12;1st International Workshop on High Performance Computing, Networking and Analytics (University of Vermont). "Developing a Dynamic Model of Cascading Failure for High Performance Computing using

  16. Notes from the 3rd Axion Strategy Meeting

    SciTech Connect (OSTI)

    Baker, O. K. [Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520 (United States); Cantatore, G. [Universita and INFN Trieste, via Valerio 2, 34127 Trieste (Italy); Jaeckel, J. [Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE (United Kingdom); Mueller, G. [Department of Physics, University of Florida, PO Box 118440, Gainesville, FL 32611 (United States)

    2010-08-30T23:59:59.000Z

    In this note we briefly summarize the main future targets and strategies for axion and general low energy particle physics identified in the ''3rd axion strategy meeting'' held during the AXIONS 2010 workshop. This summary follows a wide discussion with contributions from many of the workshop attendees.

  17. Axion Stars in the Infrared Limit

    E-Print Network [OSTI]

    Joshua Eby; Peter Suranyi; Cenalo Vaz; L. C. R. Wijewardhana

    2015-02-06T23:59:59.000Z

    Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, $f_a$, satisfying $\\delta=(f_a\\,/\\,M_P)^2\\ll 1$, where $M_P$ is the Planck mass. Similarly, the applicability of the Ruffini-Bonazzola method to axion stars also requires that the relative binding energy of axions satisfies $\\Delta=\\sqrt{1-(E_a\\,/\\,m_a)^2}\\ll1$, where $E_a$ and $m_a$ are the energy and mass of the axion. The simultaneous expansion of the equations of motion in $\\delta$ and $\\Delta$ leads to a simplified set of equations, depending only on the parameter, $\\lambda=\\sqrt{\\delta}\\,/\\,\\Delta$ in leading order of the expansions. Keeping leading order in $\\Delta$ is equivalent to the infrared limit, in which only relevant and marginal terms contribute to the equations of motion. The number of axions in the star is uniquely determined by $\\lambda$. Numerical solutions are found in a wide range of $\\lambda$. At small $\\lambda$ the mass and radius of the axion star rise linearly with $\\lambda$. While at larger $\\lambda$ the radius of the star continues to rise, the mass of the star, $M$, attains a maximum at $\\lambda_{\\rm max}\\simeq 0.58$. All stars are unstable for $\\lambda>\\lambda_{\\rm max}$ . We discuss the relationship of our results to current observational constraints on dark matter and the phenomenology of Fast Radio Bursts.

  18. ACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 2010 ACEEE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the output power directly from the shaft without any need to calculate losses. Conventionally, the shaftACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 1 © 2010 ACEEE DOI: 01.ijepe.01.01.01 Energy Audit And Management Of Induction Motor Using Field Test And Genetic

  19. Bombs unbuilt : power, ideas and institutions in international politics

    E-Print Network [OSTI]

    Walsh, James Joseph, 1959-

    2001-01-01T23:59:59.000Z

    Nuclear weapons are the most powerful weapons in human history, but contrary to virtually every prediction by scholars, relatively few states have acquired them. Why are there so few nuclear weapons states? What factors ...

  20. Lattice QCD input for axion cosmology

    E-Print Network [OSTI]

    Evan Berkowitz; Michael I. Buchoff; Enrico Rinaldi

    2015-05-27T23:59:59.000Z

    One intriguing BSM particle is the QCD axion, which could simultaneously provide a solution to the Strong CP problem and account for some, if not all, of the dark matter density in the universe. This particle is a pNGB of the conjectured Peccei-Quinn (PQ) symmetry of the Standard Model. Its mass and interactions are suppressed by a heavy symmetry breaking scale, $f_a$, whose value is roughly greater than $10^{9}$ GeV (or, conversely, the axion mass, $m_a$, is roughly less than $10^4\\ \\mu \\text{eV}$). The density of axions in the universe, which cannot exceed the relic dark matter density and is a quantity of great interest in axion experiments like ADMX, is a result of the early-universe interplay between cosmological evolution and the axion mass as a function of temperature. The latter quantity is proportional to the second derivative of the QCD free energy with respect to the CP-violating phase, $\\theta$. However, this quantity is generically non-perturbative and previous calculations have only employed instanton models at the high temperatures of interest (roughly 1 GeV). In this and future works, we aim to calculate the temperature-dependent axion mass at small $\\theta$ from first-principle lattice calculations, with controlled statistical and systematic errors. Once calculated, this temperature-dependent axion mass is input for the classical evolution equations of the axion density of the universe. Due to a variety of lattice systematic effects at the very high temperatures required, we perform a calculation of the leading small-$\\theta$ cumulant of the theta vacua on large volume lattices for SU(3) Yang-Mills with high statistics as a first proof of concept, before attempting a full QCD calculation in the future. From these pure glue results, the misalignment mechanism yields the axion mass bound $m_a \\geq (14.6\\pm0.1) \\ \\mu \\text{eV}$ when PQ-breaking occurs after inflation.

  1. Axion-dilaton cosmology and dark energy

    SciTech Connect (OSTI)

    Catena, Riccardo; Moeller, Jan, E-mail: catena@sissa.it, E-mail: janmoe@mail.desy.de [Deutsches Elektronen-Synchrotron DESY, Theory Group, Notkestrasse 85, D-22603 Hamburg (Germany)

    2008-03-15T23:59:59.000Z

    We discuss a class of flat FRW cosmological models based on D = 4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in the absence of cosmological background fluids. We observe that, once we impose the existence of radiation- and matter-dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. Explicit computations are done considering a universal metric coupling between the dilaton and the matter fields. As a result we find that during the matter-dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions.

  2. Axion inflation in type II string theory

    SciTech Connect (OSTI)

    Grimm, Thomas W. [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany) and Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2008-06-15T23:59:59.000Z

    Inflationary models driven by a large number of axion fields are discussed in the context of type IIB compactifications with N=1 supersymmetry. The inflatons arise as the scalar modes of the R-R two-forms evaluated on vanishing two-cycles in the compact geometry. The vanishing cycles are resolved by small two-volumes or NS-NS B fields which sit together with the inflatons in the same supermultiplets. String world sheets wrapping the vanishing cycles correct the metric of the R-R inflatons. They can help to generate kinetic terms close to the Planck scale and a mass hierarchy between the axions and their nonaxionic partners during inflation. At small string coupling, D-brane corrections are subleading in the metric of the R-R inflatons. However, an axion potential can be generated by D1 instantons or gaugino condensates on D5-branes. Models with a sufficiently large number of axions admit regions of chaotic inflation which can stretch over the whole axion field range for potentials from gaugino condensates. These models could allow for a possibly detectable amount of gravitational waves with tensor to scalar ratio as high as r<0.14.

  3. Lattice QCD input for axion cosmology

    E-Print Network [OSTI]

    Berkowitz, Evan; Rinaldi, Enrico

    2015-01-01T23:59:59.000Z

    One intriguing BSM particle is the QCD axion, which could simultaneously provide a solution to the Strong CP problem and account for some, if not all, of the dark matter density in the universe. This particle is a pNGB of the conjectured Peccei-Quinn (PQ) symmetry of the Standard Model. Its mass and interactions are suppressed by a heavy symmetry breaking scale, $f_a$, whose value is roughly greater than $10^{9}$ GeV (or, conversely, the axion mass, $m_a$, is roughly less than $10^4\\ \\mu \\text{eV}$). The density of axions in the universe, which cannot exceed the relic dark matter density and is a quantity of great interest in axion experiments like ADMX, is a result of the early-universe interplay between cosmological evolution and the axion mass as a function of temperature. The latter quantity is proportional to the second derivative of the QCD free energy with respect to the CP-violating phase, $\\theta$. However, this quantity is generically non-perturbative and previous calculations have only employed ins...

  4. Axion-Dilaton Cosmology and Dark Energy

    E-Print Network [OSTI]

    Riccardo Catena; Jan Möller

    2007-09-12T23:59:59.000Z

    We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation -and matter- dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions.

  5. Axions and the strong CP problem

    SciTech Connect (OSTI)

    Kim, Jihn E.; Carosi, Gianpaolo [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Physical Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2010-01-15T23:59:59.000Z

    Current upper bounds on the neutron electric dipole moment constrain the physically observable quantum chromodynamic (QCD) vacuum angle |{theta}|(less-or-similar sign)10{sup -11}. Since QCD explains a great deal of experimental data from the 100 MeV to the TeV scale, it is desirable to explain this smallness of |{theta}| in the QCD framework; this is the strong CP problem. There now exist two plausible solutions to this problem, one of which leads to the existence of a very light axion. The axion decay constant window, 10{sup 9}(less-or-similar sign)F{sub a}(less-or-similar sign)10{sup 12} GeV for an O(1) initial misalignment angle {theta}{sub 1}, has been obtained from astrophysical and cosmological data. For F{sub a}(greater-or-similar sign)10{sup 12} GeV with {theta}{sub 1}axions may constitute a significant fraction of the dark matter of the universe. The supersymmetrized axion solution of the strong CP problem introduces its superpartner the axino, which might have affected the evolution of the Universe significantly. The very light axion (theory, supersymmetrization, and models) using recent particle, astrophysical, and cosmological data, and present prospects for its discovery is reviewed here.

  6. Axion Constraints in Non-standard Thermal Histories

    SciTech Connect (OSTI)

    Grin, Daniel; Smith, Tristan; Kamionkowski, Marc [California Institute of Technology, Mail Code 130-33, Pasadena, CA 91125 (United States)

    2009-09-08T23:59:59.000Z

    There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins as late as {approx}1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more modest change to axion constraints occurs. Future possible constraints to axions and low-temperature reheating are discussed.

  7. Thermal axion constraints in non-standard thermal histories

    SciTech Connect (OSTI)

    Grin, Daniel; Smith, Tristan; Kamionkowski, Marc [California Institute of Technology, Mail Code 130-33, Pasadena, CA 91125 (United States)

    2010-08-30T23:59:59.000Z

    There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins as late as {approx}1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more modest change to axion constraints occurs. Future possible constraints to axions and low-temperature reheating are discussed.

  8. Bose-Einstein Condensation of Dark Matter Axions

    SciTech Connect (OSTI)

    Sikivie, P.; Yang, Q. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2009-09-11T23:59:59.000Z

    We show that cold dark matter axions thermalize and form a Bose-Einstein condensate (BEC). We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the nonlinear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.

  9. Thermal axion constraints in non-standard thermal histories

    E-Print Network [OSTI]

    Daniel Grin; Tristan Smith; Marc Kamionkowski

    2009-11-10T23:59:59.000Z

    There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins at temperatures as low as 1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more modest change to axion constraints occurs. Future possible constraints to axions and low-temperature reheating are discussed.

  10. SQUID-based Resonant Detection of Axion Dark Matter

    E-Print Network [OSTI]

    Vladimir Popov

    2014-10-24T23:59:59.000Z

    A new method for searching for Dark Matter axions is proposed. It is shown that a two-contact SQUID can detect oscillating magnetic perturbations induced by the axions in a strong inhomogeneous magnetic field. A resonant signal is a steplike response in the SQUID current-voltage characteristic at a voltage corresponding to the axion mass with a height depending on the axion energy density near the Earth. The proposed experimental technique appears to be sensitive to the axions with masses $m_a\\lesssim 10^{-4}$ eV, which is well-motivated by current researches both in cosmology and in particle physics.

  11. Resonantly-enhanced axion-photon regeneration Guido Mueller, Pierre Sikivie, David B. Tanner,

    E-Print Network [OSTI]

    Tanner, David B.

    Resonantly-enhanced axion-photon regeneration Guido Mueller, Pierre Sikivie, David B. Tanner to search for the axion or axion-like particles is discussed. Photons enter a strong magnetic field and some are converted to axions; the axions can pass through an opaque wall and some may convert back to photons

  12. INTERNATIONAL STATIONARY FUEL CELL DEMONSTRATION John Vogel, Plug Power Inc.

    E-Print Network [OSTI]

    control algorithms to improve cost of energy. Cost of Energy Algorithms Ref Air Stack Air Cat Flow Ref Air-TEK 14 February, 2007 Clean, Reliable On-site Energy #12;SAFE HARBOR STATEMENT This presentation Power Inc. #12;ORGANIZATIONAL CHART J. Vogel #12;PROJECT OVERVIEW AND OBJECTIVES Develop, test

  13. Axion Stars and Fast Radio Bursts

    E-Print Network [OSTI]

    A. Iwazaki

    2014-10-23T23:59:59.000Z

    We show that fast radio bursts arise from collisions between axion stars and neutron stars. The bursts are emitted in the atmosphere of the neutron stars. The observed frequencies of the bursts are given by the axion mass $m_a$ such as $m_a/2\\pi\\simeq 1.4\\,\\mbox{GHz}\\,\\big(m_a/(6\\times 10^{-6}\\mbox{eV})\\big)$. From the event rate $\\sim 10^{-3}$ per year in a galaxy, we can determine the mass $\\sim 10^{-11}M_{\\odot}$ of the axion stars. Using these values we can explain short durations ( $\\sim $ms ) and amount of radiation energies ( $\\sim 10^{43}$GeV ) of the bursts.

  14. Cosmological Axion Problem in Chaotic Inflationary Universe

    E-Print Network [OSTI]

    S. Kasuya; M. Kawasaki; T. Yanagida

    1997-05-16T23:59:59.000Z

    We investigate two cosmological axion problems (isocurvature fluctuations and domain-wall formation) in chaotic inflationary universe. It is believed that these problems are solved if potential for the Peccei-Quinn scalar field is very flat. However, we find that too many domain walls are produced through parametric resonance decay of the Peccei-Quinn scalar field. Only the axion model with N=1(N: QCD anomaly factor) is consistent with observations. We also point out that the flat potential is naturally obtained in a supersymmetric extension of the Peccei-Quinn model. If Peccei-Quinn breaking scale $F_a$ is about 10^{12} GeV, this model predicts anisotropies of cosmic microwave background radiation due to the axion isocurvature fluctuations which may be detectable in future observations.

  15. Axion cold dark matter in nonstandard cosmologies

    SciTech Connect (OSTI)

    Visinelli, Luca; Gondolo, Paolo [Department of Physics and Astronomy, University of Utah, 115 South 1400 East 201, Salt Lake City, Utah 84112-0830 (United States)

    2010-03-15T23:59:59.000Z

    We study the parameter space of cold dark matter axions in two cosmological scenarios with nonstandard thermal histories before big bang nucleosynthesis: the low-temperature reheating (LTR) cosmology and the kination cosmology. If the Peccei-Quinn symmetry breaks during inflation, we find more allowed parameter space in the LTR cosmology than in the standard cosmology and less in the kination cosmology. On the contrary, if the Peccei-Quinn symmetry breaks after inflation, the Peccei-Quinn scale is orders of magnitude higher than standard in the LTR cosmology and lower in the kination cosmology. We show that the axion velocity dispersion may be used to distinguish some of these nonstandard cosmologies. Thus, axion cold dark matter may be a good probe of the history of the Universe before big bang nucleosynthesis.

  16. Isocurvature forecast in the anthropic axion window

    SciTech Connect (OSTI)

    Hamann, J. [LAPTh, Université de Savoie, CNRS, BP 110, F-74941 Annecy-le-Vieux Cedex (France); Hannestad, S. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Raffelt, G.G. [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Wong, Y.Y.Y., E-mail: hamann@lapp.in2p3.fr, E-mail: sth@phys.au.dk, E-mail: raffelt@mppmu.mpg.de, E-mail: yvonne.wong@cern.ch [Theory Division, Physics Department, CERN, CH-1211 Genève 23 (Switzerland)

    2009-06-01T23:59:59.000Z

    We explore the cosmological sensitivity to the amplitude of isocurvature fluctuations that would be caused by axions in the ''anthropic window'' where the axion decay constant f{sub a} >> 10{sup 12} GeV and the initial misalignment angle ?{sub i} << 1. In a minimal ?CDM cosmology extended with subdominant scale-invariant isocurvature fluctuations, existing data constrain the isocurvature fraction to ? < 0.09 at 95% C.L. If no signal shows up, Planck can improve this constraint to 0.042 while an ultimate CMB probe limited only by cosmic variance in both temperature and E-polarisation can reach 0.017, about a factor of five better than the current limit. In the parameter space of f{sub a} and H{sub I} (Hubble parameter during inflation) we identify a small region where axion detection remains within the reach of realistic cosmological probes.

  17. Axions as quintessence in string theory

    SciTech Connect (OSTI)

    Panda, Sudhakar [Harish-Chandra Research Institute, Allahabad 211019 (India); Sumitomo, Yoske; Trivedi, Sandip P. [Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2011-04-15T23:59:59.000Z

    We construct a model of quintessence in string theory based on the idea of axion monodromy as discussed by McAllister, Silverstein and Westphal [L. McAllister, E. Silverstein, and A. Westphal, Phys. Rev. D 82, 046003 (2010)]. In the model, the quintessence field is an axion whose shift symmetry is broken by the presence of 5-branes which are placed in highly warped throats. This gives rise to a potential for the axion field which is slowly varying, even after incorporating the effects of moduli stabilization and supersymmetry breaking. We find that the resulting time dependence in the equation of state of dark energy is potentially detectable, depending on the initial conditions. The model has many very light extra particles which live in the highly warped throats, but these are hard to detect. A signal in the rotation of the CMB polarization can also possibly arise.

  18. Viable axion from gauged flavor symmetries

    SciTech Connect (OSTI)

    Berenstein, David; Perkins, Erik [Department of Physics, University of California, Santa Barbara, California 93106 (United States)

    2010-11-15T23:59:59.000Z

    We consider a string-inspired nonsupersymmetric extension of the standard model with gauged anomalous U(1) flavor symmetries. Consistency requires the Green-Schwarz (GS) mechanism to cancel mixed anomalies. The additional required scalars provide Stueckelberg masses for the Z{sup '} particles associated to the gauged flavor symmetry, so they decouple at low energies. Our models also include a complex scalar field {phi} to generate Froggatt-Nielsen mass terms for light particles, giving a partial solution to the fermion mass problem. A residual approximate (anomalous) global symmetry survives at low energies. The associated pseudo-Goldstone mode is the phase of the {phi} scalar field, and it becomes the dominant contribution to the physical axion. An effective field theory analysis that includes neutrino masses gives a prediction for the axion decay constant. We find a simple model where the axion decay constant is in the center of the allowed window.

  19. Solitonic axion condensates modeling dark matter halos

    SciTech Connect (OSTI)

    Castañeda Valle, David, E-mail: casvada@gmail.com; Mielke, Eckehard W., E-mail: ekke@xanum.uam.mx

    2013-09-15T23:59:59.000Z

    Instead of fluid type dark matter (DM), axion-like scalar fields with a periodic self-interaction or some truncations of it are analyzed as a model of galaxy halos. It is probed if such cold Bose–Einstein type condensates could provide a viable soliton type interpretation of the DM ‘bullets’ observed by means of gravitational lensing in merging galaxy clusters. We study solitary waves for two self-interacting potentials in the relativistic Klein–Gordon equation, mainly in lower dimensions, and visualize the approximately shape-invariant collisions of two ‘lump’ type solitons. -- Highlights: •An axion model of dark matter is considered. •Collision of axion type solitons are studied in a two dimensional toy model. •Relations to dark matter collisions in galaxy clusters are proposed.

  20. Axion emission from a magnetized neutron gas

    SciTech Connect (OSTI)

    Skobelev, V. V., E-mail: v.skobelev@inbox.ru [Moscow State Industrial University (Russian Federation)

    2011-01-15T23:59:59.000Z

    By using the polarization density matrix for a neutron in a magnetic field, the axion luminosity of magnetic neutron stars that is associated with the flip of the anomalous magnetic moment of degenerate nonrelativistic neutrons is calculated. It is shown that, at values of the magnetic-field induction in the region B Greater-Than-Or-Equivalent-To 10{sup 18} G, this mechanism of axion emission is dominant in 'young' neutron stars of temperature about a few tens of MeV units. At B {approx} 10{sup 17} G, it is one of the basic mechanisms. The Fermi energy of a degenerate neutron gas in a magnetic field is found, and it is shown that there is no such mechanism of axion emission in the degenerate case.

  1. Dark matter through the axion portal

    SciTech Connect (OSTI)

    Nomura, Yasunori; Thaler, Jesse [Berkeley Center for Theoretical Physics, University of California, Berkeley, California 94720 (United States) and Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2009-04-01T23:59:59.000Z

    Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar 'axion'. The positron excess and the absence of an antiproton or gamma ray excess constrain the axion mass and branching ratios. In the simplest realization, the axion is associated with a Peccei-Quinn symmetry, in which case it has a mass around 360-800 MeV and decays into muons. We present a simple and predictive supersymmetric model implementing this scenario, where both the Higgsino and dark matter obtain masses from the same source of TeV-scale spontaneous symmetry breaking.

  2. Axion Induced Oscillating Electric Dipole Moments

    E-Print Network [OSTI]

    Christopher T. Hill

    2015-04-10T23:59:59.000Z

    The axion electromagnetic anomaly induces an oscillating electric dipole for {\\em any} static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion in the limit that it is only locally time dependent $(\\overrightarrow{\\beta}=0)$. The electron will acquire an oscillating electric dipole of frequency $m_a$ and strength $\\sim 10^{-32}$ e-cm, three orders of magnitude above the nucleon, and within four orders of magnitude of the present standard model DC limit. This may suggest sensitive new experimental venues for the axion dark matter search.

  3. Self-gravitating system made of axions

    SciTech Connect (OSTI)

    Barranco, J.; Bernal, A. [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm (Germany); Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm (Germany)

    2011-02-15T23:59:59.000Z

    We show that the inclusion of an axionlike effective potential in the construction of a self-gravitating system of scalar fields decreases its compactness when the value of the self-interaction coupling constant is increased. By including the current values for the axion mass m and decay constant f{sub a}, we have computed the mass and the radius for self-gravitating systems made of axion particles. It is found that such objects will have asteroid size masses and radii of a few meters, thus a self-gravitating system made of axions could play the role of scalar mini-MACHOs and mimic a cold dark matter model for the galactic halo.

  4. Widening the Axion Window via Kinetic and Stückelberg Mixings

    E-Print Network [OSTI]

    Gary Shiu; Wieland Staessens; Fang Ye

    2015-03-03T23:59:59.000Z

    We point out that kinetic and St\\"uckelberg mixings that are generically present in the low energy effective action of axions can significantly widen the window of axion decay constants. We show that an effective super-Planckian decay constant can be obtained even when the axion kinetic matrix has only sub-Planckian entries. Our minimal model involves only two axions, a St\\"uckelberg U(1) and a modest rank instanton generating non-Abelian group. Below the mass of the St\\"uckelberg U(1), there is only a single axion with a non-perturbatively generated potential. In contrast to previous approaches, the enhancement of the axion decay constant is not tied to the number of degrees of freedom introduced. We also discuss how kinetic mixings can lower the decay constant to the desired axion dark matter window. String theory embeddings of this scenario and their phenomenological features are briefly discussed.

  5. CAST constraints on the axion-electron coupling

    SciTech Connect (OSTI)

    Barth, K.; Davenport, M.; Lella, L. Di [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A. [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Beltran, B.; Carmona, J.M.; Dafni, T.; Galan, J.; García, J.A. [Laboratorio de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Braeuninger, H.; Englhauser, J.; Friedrich, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Collar, J.I. [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C. [Aristoteles University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G.; Geralis, T. [National Center for Scientific Research ''Demokritos'', Athens (Greece); Ferrer-Ribas, E.; Giomataris, I. [IRFU, Centre d'Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Fischer, H.; Franz, J., E-mail: Jaime.Ruz@cern.ch, E-mail: Julia.Vogel@cern.ch, E-mail: redondo@mpp.mpg.de [Albert-Ludwigs-Universitaet Freiburg, Freiburg (Germany); and others

    2013-05-01T23:59:59.000Z

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the ''BCA processes.'' Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g{sub ae} and axion-photon interaction strength g{sub a?} using the CAST phase-I data (vacuum phase). For m{sub a}?<10 meV/c{sup 2} we find g{sub a?} g{sub ae} < 8.1 × 10{sup ?23} GeV{sup ?1} at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  6. International Power Group Ltd IPWG | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunanInformation source History View NewInternational

  7. Sea Solar Power International Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt Ltd JumpInformationScotts Corners, New York: EnergySea Solar Power

  8. International Rectifier Power Control Systems | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtelInterias Solar Energy Jump to:IES Jump to:PartnershipPower Control

  9. Beijing Tianqing Power International CDM Consulting | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomass Conversions IncBay County,SouthCity County,NewPowerSunpu Solar PV

  10. Hypothetical Dark Matter/Axion rockets: What can be said about Dark Matter in terms of space physics propulsion

    SciTech Connect (OSTI)

    Beckwith, Andrew [APS/Fermi contractor Aurora, Illinois 60502 630-840-2201 (United States)

    2009-03-16T23:59:59.000Z

    This paper discusses dark matter (DM) particle candidates from non-supersymmetry (SUSY) processes and explores how a DM candidate particle in the 100-400 GeV range could be created. Thrust from DM particles is also proposed for Photon rocket and Axion rockets. It would use a magnetic field to convert DM particles to near photonlike particles in a chamber to create thrust from the discharge of the near-photon-like particles. The presence of DM particles would suggest that thrust from the emerging near-photon-like particle would be greater than with conventional photon rockets. This amplifies and improves on an 'axion rocket ramjet' for interstellar travel. It is assumed that the same methodology used in an axion ramjet could be used with DM, with perhaps greater thrust/power conversion efficiencies.

  11. Cavity Microwave Searches for Cosmological Axions

    SciTech Connect (OSTI)

    Carosi, G; van Bibber, K

    2007-01-22T23:59:59.000Z

    This chapter will cover the search for dark matter axions based on microwave cavity experiments proposed by Pierre Sikivie. We will start with a brief overview of halo dark matter and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described as well as practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of this chapter will be the two complementary strategies for ultra-low noise detection of the microwave photons--the 'photon-as-wave' approach (i.e. conventional heterojunction amplifiers and soon to be quantum-limited SQUID devices), and 'photon-as-particle' (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The section will conclude with a discussion of future plans and challenges for the microwave cavity experiment.

  12. The instanton liquid and the axion

    E-Print Network [OSTI]

    Wantz, Olivier

    2010-05-04T23:59:59.000Z

    ). The thesis describes the significant advances made within the IILM in order to study the quark-gluon plasma in realistic parameter regimes. In particular, a determination of the temperature-dependent axion mass in the IILM lays the foundation for a critical...

  13. 2010 International Conference on Power System Technology Renewable energy integration: mechanism for

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    capacity that can integrate the wind energy blocks. Both the new grids and upgrade grid must have a stepped2010 International Conference on Power System Technology Renewable energy integration: mechanism with high uncertainty, as it usually happens with renewable energies. This work faces this problem

  14. Direct detection of dark matter axions with directional sensitivity

    SciTech Connect (OSTI)

    Irastorza, Igor G.; García, Juan A., E-mail: Igor.Irastorza@cern.ch, E-mail: jagarpas@unizar.es [Laboratorio de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C/ Pedro Cerbuna 12, 50009, Zaragoza (Spain)

    2012-10-01T23:59:59.000Z

    We study the directional effect of the expected axion dark matter signal in a resonant cavity of an axion haloscope detector, for cavity geometries not satisfying the condition that the axion de Broglie wavelength ?{sub a} is sufficiently larger than the cavity dimensions L for a fully coherent conversion, i.e. ?{sub a}?>2?L. We focus on long thin cavities immersed in dipole magnets and find, for appropriately chosen cavity lengths, an O(1) modulation of the signal with the cavity orientation with respect the momentum distribution of the relic axion background predicted by the isothermal sphere model for the galactic dark matter halo. This effect can be exploited to design directional axion dark matter detectors, providing an unmistakable signature of the extraterrestrial origin of a possible positive detection. Moreover, the precise shape of the modulation may give information of the galactic halo distribution and, for specific halo models, give extra sensitivity for higher axion masses.

  15. Cosmologically safe QCD axion as a present from extra dimension

    E-Print Network [OSTI]

    Kawasaki, Masahiro; Yanagida, Tsutomu T

    2015-01-01T23:59:59.000Z

    We propose a QCD axion model where the origin of PQ symmetry and suppression of axion isocurvature perturbations are explained by introducing an extra dimension. Each extra quark-antiquark pair lives on branes separately to suppress PQ breaking operators. The size of the extra dimension changes after inflation due to an interaction between inflaton and a bulk scalar field, which implies that the PQ symmetry can be drastically broken during inflation to suppress undesirable axion isocurvature fluctuations.

  16. On the Possibility of Large Axion Moduli Spaces

    E-Print Network [OSTI]

    Tom Rudelius

    2015-05-23T23:59:59.000Z

    We study the diameters of axion moduli spaces, focusing primarily on type IIB compactifications on Calabi-Yau three-folds. In this case, we derive a stringent bound on the diameter in the large volume region of parameter space for Calabi-Yaus with simplicial K\\"ahler cone. This bound can be violated by Calabi-Yaus with non-simplicial K\\"ahler cones, but additional contributions are introduced to the effective action which can restrict the field range accessible to the axions. We perform a statistical analysis of simulated moduli spaces, finding in all cases that these additional contributions restrict the diameter so that these moduli spaces are no more likely to yield successful inflation than those with simplicial K\\"ahler cone or with far fewer axions. Further heuristic arguments for axions in other corners of the duality web suggest that the difficulty observed in hep-th/0303252 of finding an axion decay constant parametrically larger than $M_p$ applies not only to individual axions, but to the diagonals of axion moduli space as well. This observation is shown to follow from the weak gravity conjecture of hep-th/0601001, so it likely applies not only to axions in string theory, but also to axions in any consistent theory of quantum gravity.

  17. Results on axion physics from the CAST Experiment at CERN

    E-Print Network [OSTI]

    Christos Eleftheriadis

    2007-06-05T23:59:59.000Z

    Axions are expected to be produced in the sun via the Primakoff process. They may be detected through the inverse process in the laboratory, under the influence of a strong magnetic field, giving rise to X-rays of energies in the range of a few keV. Such an Axion detector is the CERN Axion Solar Telescope (CAST), collecting data since 2003. Results have been published, pushing the axion-photon coupling g$_{a\\gamma}$ below the 10$^{-10}$ GeV$^{-1}$ limit at 95% CL, for axion masses less than 0.02 eV. This limit is nearly an order of magnitude lower than previous experimental limits and surpassed for the first time limits set from astrophysical arguments based on the energy-loss concept. The experiment is currently exploring axion masses in the range of 0.02 eV $axion mass explored will be extended up to the limit of 1.1 eV, testing for the first time the region of theoretical axion models with the axion helioscope method.

  18. axion racing team: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    far exceeds the conventional cosmological bound. Such theories have several dark matter candidates. David B. Kaplan; Kathryn M. Zurek 2005-07-29 8 QCD axion and...

  19. axion press genealogical: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    far exceeds the conventional cosmological bound. Such theories have several dark matter candidates. David B. Kaplan; Kathryn M. Zurek 2005-07-29 5 QCD axion and...

  20. Results on axion physics from the CAST Experiment at CERN

    E-Print Network [OSTI]

    Eleftheriadis, Christos A; Aune, S; Barth, K; Belov, A; Beltran, B; Bräuninger, H; Carmona, J; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Gomez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubicic, cA; Lutz, G; Luzón, G; Miller, D; Morales, A; Morales, J; Nordt, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege1, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, L; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2007-01-01T23:59:59.000Z

    Axions are expected to be produced in the sun via the Primakoff process. They may be detected through the inverse process in the laboratory, under the influence of a strong magnetic field, giving rise to X-rays of energies in the range of a few keV. Such an Axion detector is the CERN Axion Solar Telescope (CAST), collecting data since 2003. Results have been published, pushing the axion-photon coupling g$_{a\\gamma}$ below the 10$^{-10}$ GeV$^{-1}$ limit at 95% CL, for axion masses less than 0.02 eV. This limit is nearly an order of magnitude lower than previous experimental limits and surpassed for the first time limits set from astrophysical arguments based on the energy-loss concept. The experiment is currently exploring axion masses in the range of 0.02 eV $< m_a <$ 1.1 eV. In the next run, currently under preparation, the axion mass explored will be extended up to the limit of 1.1 eV, testing for the first time the region of theoretical axion models with the axion helioscope method.

  1. Mixed axion-wino dark matter

    E-Print Network [OSTI]

    Bae, Kyu Jung; Lessa, Andre; Serce, Hasan

    2015-01-01T23:59:59.000Z

    A variety of supersymmetric models give rise to a split mass spectrum characterized by very heavy scalars but sub-TeV gauginos, usually with a wino-like LSP. Such models predict a thermally-produced underabundance of wino-like WIMP dark matter so that non-thermal DM production mechanisms are necessary. We examine the case where theories with a wino-like LSP are augmented by a Peccei-Quinn sector including an axion-axino-saxion supermultiplet in either the SUSY KSVZ or SUSY DFSZ models and with/without saxion decays to axions/axinos. We show allowed ranges of PQ breaking scale f_a for various cases which are generated by solving the necessary coupled Boltzmann equations. We also present results for a model with radiatively-driven naturalness but with a wino-like LSP.

  2. Large Non-Gaussianity in Axion Inflation

    SciTech Connect (OSTI)

    Barnaby, Neil; Peloso, Marco [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2011-05-06T23:59:59.000Z

    The inflationary paradigm has enjoyed phenomenological success; however, a compelling particle physics realization is still lacking. Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry. We reconsider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields c{phi}FF-tilde, which is generically present in these models. This coupling leads to production of gauge quanta, which provide a new source of inflaton fluctuations, {delta}{phi}. For c > or approx. 10{sup 2}M{sub p}{sup -1}, these dominate over the vacuum fluctuations, and non-Gaussianity exceeds the current observational bound. This regime is typical for concrete realizations that admit a UV completion; hence, large non-Gaussianity is easily obtained in minimal and natural realizations of inflation.

  3. Discovering the QCD Axion with Black Holes and Gravitational Waves

    E-Print Network [OSTI]

    Asimina Arvanitaki; Masha Baryakhtar; Xinlu Huang

    2015-03-23T23:59:59.000Z

    Advanced LIGO may be the first experiment to detect gravitational waves. Through superradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angular momentum from the black hole. Axions transitioning between levels of the gravitational atom and axions annihilating to gravitons can produce observable gravitational wave signals. The signals are long-lasting, monochromatic, and can be distinguished from ordinary astrophysical sources. We estimate up to O(1) transition events at aLIGO for an axion between 10^-11 and 10^-10 eV and up to 10^4 annihilation events for an axion between 10^-13 and 10^-11 eV. In the event of a null search, aLIGO can constrain the axion mass for a range of rapidly spinning black hole formation rates. Axion annihilations are also promising for much lighter masses at future lower-frequency gravitational wave observatories; the rates have large uncertainties, dominated by supermassive black hole spin distributions. Our projections for aLIGO are robust against perturbations from the black hole environment and account for our updated exclusion on the QCD axion of 6*10^-13 eV < ma < 2*10^-11 eV suggested by stellar black hole spin measurements.

  4. Axion isocurvature fluctuations with extremely blue spectrum

    SciTech Connect (OSTI)

    Kasuya, Shinta [Department of Information Science, Kanagawa University, Kanagawa 259-1293 (Japan); Kawasaki, Masahiro [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Chiba 277-8582 (Japan)

    2009-07-15T23:59:59.000Z

    We construct an axion model for generating isocurvature fluctuations with blue spectrum, n{sub iso}=2-4, which is suggested by recent analyses of admixture of adiabatic and isocurvature perturbations with independent spectral indices, n{sub ad}{ne}n{sub iso}. The distinctive feature of the model is that the spectrum is blue at large scales while scale invariant at small scales. This is naturally realized by the dynamics of the Peccei-Quinn scalar field.

  5. Experimental determination of radiated internal wave power without pressure field data

    SciTech Connect (OSTI)

    Lee, Frank M.; Morrison, P. J. [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States); Paoletti, M. S.; Swinney, Harry L. [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)

    2014-04-15T23:59:59.000Z

    We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ?. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

  6. Multiverse Dark Matter: SUSY or Axions

    E-Print Network [OSTI]

    Francesco D'Eramo; Lawrence J. Hall; Duccio Pappadopulo

    2015-03-11T23:59:59.000Z

    The observed values of the cosmological constant {\\it and} the abundance of Dark Matter (DM) can be successfully understood, using certain measures, by imposing the anthropic requirement that density perturbations go non-linear and virialize to form halos. This requires a probability distribution favoring low amounts of DM, i.e. low values of the PQ scale $f$ for the QCD axion and low values of the superpartner mass scale $\\tilde{m}$ for LSP thermal relics. In theories with independent scanning of multiple DM components, there is a high probability for DM to be dominated by a single component. For example, with independent scanning of $f$ and $\\tilde{m}$, TeV-scale LSP DM and an axion solution to the strong CP problem are unlikely to coexist. With thermal LSP DM, the scheme allows an understanding of a Little SUSY Hierarchy with multi-TeV superpartners. Alternatively, with axion DM, PQ breaking before (after) inflation leads to $f$ typically below (below) the projected range of the current ADMX experiment of $f = (3 - 30) \\times 10^{11}$ GeV, providing strong motivation to develop experimental techniques for probing lower $f$.

  7. Multiverse Dark Matter: SUSY or Axions

    E-Print Network [OSTI]

    D'Eramo, Francesco; Pappadopulo, Duccio

    2014-01-01T23:59:59.000Z

    The observed values of the cosmological constant {\\it and} the abundance of Dark Matter (DM) can be successfully understood, using certain measures, by imposing the anthropic requirement that density perturbations go non-linear and virialize to form halos. This requires a probability distribution favoring low amounts of DM, i.e. low values of the PQ scale $f$ for the QCD axion and low values of the superpartner mass scale $\\tilde{m}$ for LSP thermal relics. In theories with independent scanning of multiple DM components, there is a high probability for DM to be dominated by a single component. For example, with independent scanning of $f$ and $\\tilde{m}$, TeV-scale LSP DM and an axion solution to the strong CP problem are unlikely to coexist. With thermal LSP DM, the scheme allows an understanding of a Little SUSY Hierarchy with multi-TeV superpartners. Alternatively, with axion DM, PQ breaking before (after) inflation leads to $f$ typically below (below) the projected range of the current ADMX experiment of ...

  8. INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Accepted June 2008 HYDROGEN STORAGE FOR MIXED WIND-NUCLEAR POWER PLANTS IN

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    evaluation of hydrogen production and storage for a mixed wind-nuclear power plant considering some new : nuclear power plant production (MW) GP : total wind-nuclear power plant production (MW) EP : electrolyzerINTERNATIONAL JOURNAL OF HYDROGEN ENERGY Accepted June 2008 1 HYDROGEN STORAGE FOR MIXED WIND-NUCLEAR

  9. [Establishment and support of the International Power Institute]. Quarterly technical progress report, October--December, 1997

    SciTech Connect (OSTI)

    Coles, J.E.

    1998-04-02T23:59:59.000Z

    This is the quarterly report of the International Power Institute for October--December 1997. The topics of the report include pre-cooperative agreement activities, a discussion of the deputy director position, the IPI brochure, exploration of collaborative arrangements, formation of the IPI advisory board, a review of the advisory board meeting, report of a meeting with African electric utility executives, report of a visit to South Africa to explore a collaborative relationship.

  10. Cosmological problems with multiple axion-like fields

    SciTech Connect (OSTI)

    Mack, Katherine J. [Kavli Institute for Cosmology, Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Steinhardt, Paul J., E-mail: mack@ast.cam.ac.uk, E-mail: steinh@princeton.edu [Department of Physics, Princeton University, Jadwin Hall, Princeton, NJ 08544 (United States)

    2011-05-01T23:59:59.000Z

    Incorporating the QCD axion and simultaneously satisfying current constraints on the dark matter density and isocurvature fluctuations requires non-minimal fine-tuning of inflationary parameters or the axion misalignment angle (or both) for Peccei-Quinn symmetry-breaking scales f{sub a} > 10{sup 12} GeV. To gauge the degree of tuning in models with many axion-like fields at similar symmetry-breaking scales and masses, as may occur in string theoretic models that include a QCD axion, we introduce a figure of merit F that measures the fractional volume of allowed parameter space: the product of the slow roll parameter ? and each of the axion misalignment angles, ?{sub 0}. For a single axion, F?<10{sup ?11} is needed to avoid conflict with observations. We show that the fine tuning of F becomes exponentially more extreme in the case of numerous axion-like fields. Anthropic arguments are insufficient to explain the fine tuning because the bulk of the anthropically allowed parameter space is observationally ruled out by limits on the cosmic microwave background isocurvature modes. Therefore, this tuning presents a challenge to the compatibility of string-theoretic models with light axions and inflationary cosmology.

  11. Dark radiation constraints on mixed Axion/Neutralino dark matter

    SciTech Connect (OSTI)

    Bae, Kyu Jung; Baer, Howard [Dept. of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Lessa, Andre, E-mail: bae@nhn.ou.edu, E-mail: baer@nhn.ou.edu, E-mail: lessa@fma.if.usp.br [Instituto de Física, Universidade de São Paulo, São Paulo - SP (Brazil)

    2013-04-01T23:59:59.000Z

    Recent analyses of CMB data combined with the measurement of BAO and H{sub 0} show that dark radiation — parametrized by the apparent number of additional neutrinos ?N{sub eff} contributing to the cosmic expansion — is bounded from above by about ?N{sub eff}?<1.6 at 95% CL. We consider the mixed axion/neutralino cold dark matter scenario which arises in R-parity conserving supersymmetric (SUSY) models wherein the strong CP problem is solved by hadronic axions with a concommitant axion(a)/saxion(s)/axino(ã) supermultiplet. Our new results include improved calculations of thermal axion and saxion production and include effects of saxion decay to axinos and axions. We show that the above bound on ?N{sub eff} is easily satisfied if saxions are mainly thermally produced and m{sub LSP} < m{sub ã}?axions. Furthermore we show that scenarios with mixed neutralino/axion dark matter are highly constrained by combined CMB, BBN and Xe-100 constraints. In particular, supersymmetric models with a standard overabundance of neutralino dark matter are excluded for all values of the Peccei-Quinn breaking scale. Next generation WIMP direct detection experiments may be able to discover or exclude mixed axion-neutralino CDM scenarios where s ? aa is the dominant saxion decay mode.

  12. Higgs inflation and suppression of axion isocurvature perturbation

    E-Print Network [OSTI]

    Nakayama, Kazunori

    2015-01-01T23:59:59.000Z

    We point out that cosmological constraint from the axion isocurvature perturbation is relaxed if the Higgs field obtains a large field value during inflation in the DFSZ axion model. This scenario is consistent with the Higgs inflation model, in which two Higgs doublets have non-minimal couplings and play a role of inflaton.

  13. Photon-Axion conversions in transversely inhomogeneous magnetic fields

    E-Print Network [OSTI]

    Javier Redondo

    2010-03-01T23:59:59.000Z

    We compute the photon-axion conversion probability in an external magnetic field with a strong transverse gradient in the eikonal approximation for plane waves. We find it typically smaller than a comparable uniform case. Some insights into the phenomenon of photon-axion splitting are given.

  14. Photon and Axion Splitting in an Inhomogeneous Magnetic Field

    E-Print Network [OSTI]

    E. I. Guendelman

    2008-02-03T23:59:59.000Z

    The axion photon system in an external magnetic field, when the direction of propagation of axions and photons is orthogonal to the direction of the external magnetic field, displays a continuous axion-photon duality symmetry in the limit the axion mass is neglected. The conservation law that follow in this effective 2+1 dimensional theory from this symmetry is obtained. The magnetic field interaction is seen to be equivalent to first order to the interaction of a complex charged field with an external electric potential, where this ficticious "electric potential" is proportional to the external magnetic field. This allows one to solve for the scattering amplitudes using already known scalar QED results. From the scalar QED analog the axion and the photon are symmetric and antisymmetric combinations of particle and antiparticle. If one considers therefore scattering experiments in which the two spatial dimensions of the effective theory are involved non trivially, one observes that both particle and antiparticle components of photons and axions are preferentially scattered in different directions, thus producing the splitting or decomposition of the photon and axion into their particle and antiparticle components in an inhomogeneous magnetic field. This observable in principle effect is of first order in the axion photon coupling, unlike the "light shining through a wall phenomena ", which is second order.

  15. Higgs inflation and suppression of axion isocurvature perturbation

    E-Print Network [OSTI]

    Kazunori Nakayama; Masahiro Takimoto

    2015-05-22T23:59:59.000Z

    We point out that cosmological constraint from the axion isocurvature perturbation is relaxed if the Higgs field obtains a large field value during inflation in the DFSZ axion model. This scenario is consistent with the Higgs inflation model, in which two Higgs doublets have non-minimal couplings and play a role of inflaton.

  16. axion dark matter: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    axion dark matter First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Dark matter axions HEP -...

  17. Diluting the inflationary axion fluctuation by a stronger QCD in the early Universe

    E-Print Network [OSTI]

    Choi, Kiwoon; Im, Sang Hui; Jeong, Kwang Sik

    2015-01-01T23:59:59.000Z

    We propose a new mechanism to suppress the axion isocurvature perturbation, while producing the right amount of axion dark matter, within the framework of supersymmetric axion models with the axion scale induced by supersymmetry breaking. The mechanism involves an intermediate phase transition to generate the Higgs \\mu-parameter, before which the weak scale is comparable to the axion scale and the resulting stronger QCD yields an axion mass heavier than the Hubble scale over a certain period. Combined with that the Hubble-induced axion scale during the primordial inflation is well above the intermediate axion scale at present, the stronger QCD in the early Universe suppresses the axion fluctuation to be small enough even when the inflationary Hubble scale saturates the current upper bound, while generating an axion misalignment angle of order unity.

  18. An improved cosmological bound on the thermal axion mass

    E-Print Network [OSTI]

    Alessandro Melchiorri; Olga Mena; Anze Slosar

    2007-05-18T23:59:59.000Z

    Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous cosmological bounds on the axion mass m_a in the so-called hadronic axion window. We obtain a limit on the axion mass m_a axion mass. If neutrino masses belong to an inverted hierarchy scheme, for example, the above constraint is improved to m_a < 0.38eV at the 95% c.l. (m_a < 0.67eV at the 99% c.l.). Future data from experiments as CAST will provide a direct test of the cosmological bound.

  19. Mechanical Energy and Power Systems Laboratory Mechanical Energy and Power Systems Laboratory Proceedings of the ASME 2009 International Mechanical Engineering Conference and

    E-Print Network [OSTI]

    Van de Ven, James D.

    Mechanical Energy and Power Systems Laboratory Mechanical Energy and Power Systems Laboratory Proceedings of the ASME 2009 International Mechanical Engineering Conference and Exposition ASME/IMECE 2009 Copyright c 2009 by ASME Dr. James D. Van de Ven #12;seal, and several of it's important variables.C(3

  20. Constraints on the axion-electron coupling for solar axions produced by a Compton process and bremsstrahlung

    SciTech Connect (OSTI)

    Derbin, A. V.; Kayunov, A. S.; Muratova, V. V.; Semenov, D. A.; Unzhakov, E. V. [St. Petersburg Nuclear Physics Institute, Gatchina, 188300 (Russian Federation)

    2011-01-15T23:59:59.000Z

    The search for solar axions produced by Compton ({gamma}+e{sup -}{yields}e{sup -}+A) and bremsstrahlunglike (e{sup -}+Z{yields}Z+e{sup -}+A) processes has been performed. The axion flux in both cases depends on the axion-electron coupling constant. The resonant excitation of the low-lying nuclear level of {sup 169}Tm was looked for: A+{sup 169}Tm{yields}{sup 169}Tm{sup *}{yields}{sup 169}Tm+{gamma} (8.41 keV). The Si(Li) detector and {sup 169}Tm target installed inside the low-background setup were used to detect 8.41 keV {gamma} rays. As a result, a new model-independent restriction on the axion-electron and the axion-nucleon couplings was obtained: g{sub Ae}x|g{sub AN}{sup 0}+g{sub AN}{sup 3}|{<=}2.1x10{sup -14}. In the model of the hadronic axion this restriction corresponds to the upper limit on the axion-electron coupling and on the axion mass g{sub Ae}xm{sub A{<=}}3.1x10{sup -7} eV (90% C.L.). The limits on the axion mass are m{sub A{<=}}105 eV and m{sub A{<=}}1.3 keV for the Dine-Fischler-Srednicki-Zhitnitskii- and Kim-Shifman-Vainstein-Zakharov-axion models, correspondingly (90% C.L.).

  1. Electrical power system failure detection, isolation and recovery on the International Space Station Alpha

    SciTech Connect (OSTI)

    Aghabarari, E. [Rockwell International, Canoga Park, CA (United States). Rocketdyne Division; Varney, J. [McDonnell Douglas, Houston, TX (United States)

    1995-12-31T23:59:59.000Z

    The problem of how to detect, isolate, and recover from failures on the International Space Station Alpha (ISSA) is currently under study and development by NASA and a number of contractors including Rocketdyne Division of Rockwell International. The effort is planned to provide an advanced real-time failure detection system for the station. The autonomous power system project is designed to demonstrate the abilities of integrated intelligent diagnosis, control and scheduling techniques to space power distribution hardware. In this paper the latest failure detection, isolation, and recovery (FDIR) design, which provides an autonomous FDIR for the Electric Power System (EPS), will be described. The ISSA Concept of Operations and Utilization (COU) defines the ability of the vehicle to ``survive 24 hours of operation without crew or ground intervention``. This results in a necessity to design and develop automatic failure detection techniques to accomplish such autonomous operation without routine commanding. This paper addresses the current EPS FDIR design concept and concentrates on how to resolve the FDIR issues and come up with a robust design to recover from abnormal behavior.

  2. Safety and Nonsafety Communications and Interactions in International Nuclear Power Plants

    SciTech Connect (OSTI)

    Kisner, Roger A [ORNL; Mullens, James Allen [ORNL; Wilson, Thomas L [ORNL; Wood, Richard Thomas [ORNL; Korsah, Kofi [ORNL; Qualls, A L [ORNL; Muhlheim, Michael David [ORNL; Holcomb, David Eugene [ORNL; Loebl, Andy [ORNL

    2007-08-01T23:59:59.000Z

    Current industry and NRC guidance documents such as IEEE 7-4.3.2, Reg. Guide 1.152, and IEEE 603 do not sufficiently define a level of detail for evaluating interdivisional communications independence. The NRC seeks to establish criteria for safety systems communications that can be uniformly applied in evaluation of a variety of safety system designs. This report focuses strictly on communication issues related to data sent between safety systems and between safety and nonsafety systems. Further, the report does not provide design guidance for communication systems nor present detailed failure modes and effects analysis (FMEA) results for existing designs. This letter report describes communications between safety and nonsafety systems in nuclear power plants outside the United States. A limited study of international nuclear power plants was conducted to ascertain important communication implementations that might have bearing on systems proposed for licensing in the United States. This report provides that following information: 1.communications types and structures used in a representative set of international nuclear power reactors, and 2.communications issues derived from standards and other source documents relevant to safety and nonsafety communications. Topics that are discussed include the following: communication among redundant safety divisions, communications between safety divisions and nonsafety systems, control of safety equipment from a nonsafety workstation, and connection of nonsafety programming, maintenance, and test equipment to redundant safety divisions during operation. Information for this report was obtained through publicly available sources such as published papers and presentations. No proprietary information is represented.

  3. The Axion from Five-Dimensional Supergravity

    E-Print Network [OSTI]

    McReynolds, Sean

    2007-01-01T23:59:59.000Z

    We consider the axion arising from five-dimensional supergravity in the presence of boundaries. We find the approximate bosonic effective action to estimate the lower bound on the "Peccei-Quinn" energy scale with a flat bulk. With a warped bulk, one can obtain a scale within the standard window; this puts a bound on the required curvature scale relative to the proper separation between boundaries. We comment on the scalar potential that may ruin the strong-CP resolution, and the effective derivative coupling to matter in 5D hypermultiplets.

  4. The Axion from Five-Dimensional Supergravity

    E-Print Network [OSTI]

    Sean McReynolds

    2007-07-03T23:59:59.000Z

    We consider the axion arising from five-dimensional supergravity in the presence of boundaries. We find the approximate bosonic effective action to estimate the lower bound on the "Peccei-Quinn" energy scale with a flat bulk. With a warped bulk, one can obtain a scale within the standard window; this puts a bound on the required curvature scale relative to the proper separation between boundaries. We comment on the scalar potential that may ruin the strong-CP resolution, and the effective derivative coupling to matter in 5D hypermultiplets.

  5. Proceedings of the Third International Workshop on the implementation of ALARA at nuclear power plants

    SciTech Connect (OSTI)

    Khan, T.A. [comp.] [Brookhaven National Lab., Upton, NY (United States); Roecklein, A.K. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications

    1995-03-01T23:59:59.000Z

    This report contains the papers presented and the discussions that took place at the Third International Workshop on ALARA Implementation at Nuclear Power Plants, held in Hauppauge, Long Island, New York from May 8--11, 1994. The purpose of the workshop was to bring together scientists, engineers, health physicists, regulators, managers and other persons who are involved with occupational dose control and ALARA issues. The countries represented were: Canada, Finland, France, Germany, Japan, Korea, Mexico, the Netherlands, Spain, Sweden, the United Kingdom and the United States. The workshop was organized into twelve sessions and three panel discussions. Individual papers have been cataloged separately.

  6. Magnetic helicity generation from the cosmic axion field

    SciTech Connect (OSTI)

    Campanelli, L.; Giannotti, M. [Dipartimento di Fisica, Universita di Ferrara, I-44100 Ferrara (Italy); INFN-Sezione di Ferrara, I-44100 Ferrara (Italy)

    2005-12-15T23:59:59.000Z

    The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about vertical bar H{sub B} vertical bar {approx_equal}(10{sup -20}G){sup 2} kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.

  7. Magnetic Helicity Generation from the Cosmic Axion Field

    E-Print Network [OSTI]

    L. Campanelli; M. Giannotti

    2005-12-12T23:59:59.000Z

    The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about |H_B| \\simeq (10^{-20} G)^2 kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.

  8. Dilution of axion dark radiation by thermal inflation

    E-Print Network [OSTI]

    Hattori, Hironori; Omoto, Naoya; Seto, Osamu

    2015-01-01T23:59:59.000Z

    Axion in the Peccei-Quinn (PQ) mechanism provides a promising solution to the strong CP problem in the standard model of particle physics. Coherently generated PQ scalar fields could dominate the energy density in the early Universe and decay into relativistic axions, which would confront with the current dark radiation constraints. We study the possibility that a thermal inflation driven by a $U(1)$ gauged Higgs field dilutes such axions. A well motivated extra gauged $U(1)$ would be the local $B-L$ symmetry. We also discuss the implication for the case of $U(1)_{B-L}$ and available baryogenesis mechanism in such cosmology.

  9. Modeling of reciprocating internal combustion engines for power generation and heat recovery

    SciTech Connect (OSTI)

    Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

    2013-02-01T23:59:59.000Z

    This paper presents a power generation and heat recovery model for reciprocating internal combustion engines (ICEs). The purpose of the proposed model is to provide realistic estimates of performance/efficiency maps for both electrical power output and useful thermal output for various capacities of engines for use in a preliminary CHP design/simulation process. The proposed model will serve as an alternative to constant engine efficiencies or empirical efficiency curves commonly used in the current literature for simulations of CHP systems. The engine performance/efficiency calculation algorithm has been coded to a publicly distributed FORTRAN Dynamic Link Library (DLL), and a user friendly tool has been developed using Visual Basic programming. Simulation results using the proposed model are validated against manufacturer’s technical data.

  10. Comparison of Different Internal Dosimetry Systems for Selected Radionuclides Important to Nuclear Power Production

    SciTech Connect (OSTI)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Manger, Ryan P [ORNL

    2013-08-01T23:59:59.000Z

    This report compares three different radiation dosimetry systems currently applied by various U.S. Federal agencies and dose estimates based on these three dosimetry systems for a set of radionuclides often identified in power reactor effluents. These dosimetry systems were developed and applied by the International Commission on Radiological Protection at different times over the past six decades. Two primary modes of intake of radionuclides are addressed: ingestion in drinking water and inhalation. Estimated doses to individual organs and to the whole body based on each dosimetry system are compared for each of four age groups: infant, child, teenager, and adult. Substantial differences between dosimetry systems in estimated dose per unit intake are found for some individual radionuclides, but differences in estimated dose per unit intake generally are modest for mixtures of radionuclides typically found in nuclear power plant effluents.

  11. Fourth International Workshop on Large-Scale Integration of Wind Power and Transmission Networks for Offshore Wind Farms,

    E-Print Network [OSTI]

    for Offshore Wind Farms, 20-21 October 2003, Billund, Denmark C. S. Nielsen, Hans F. Ravn, Camilla Schaumburg1 Fourth International Workshop on Large-Scale Integration of Wind Power and Transmission Networks of Denmark, B. 321, DK-2800 Lyngby, Denmark, csm@imm.dtu.dk Two wind power prognosis criteria and regulating

  12. Production and Detection of Axion-Like Particles in a HERA Dipole Magnet - Letter-of-Intent for the ALPS experiment -

    E-Print Network [OSTI]

    Klaus Ehret; Maik Frede; Ernst-Axel Knabbe; Dietmar Kracht; Axel Lindner; Niels Meyer; Dieter Notz; Andreas Ringwald; Guenter Wiedemann

    2007-02-13T23:59:59.000Z

    Recently, the PVLAS collaboration has reported evidence for an anomalous rotation of the polarization of light in vacuum in the presence of a transverse magnetic field. This may be explained through the production of a new light spin-zero (axion-like) neutral particle coupled to two photons. In this letter-of-intent, we propose to test this hypothesis by setting up a photon regeneration experiment which exploits the photon beam of a high-power infrared laser, sent along the transverse magnetic field of a superconducting HERA dipole magnet. The proposed ALPS (Axion-Like Particle Search) experiment offers a window of opportunity for a rapid firm establishment or exclusion of the axion-like particle interpretation of the anomaly published by PVALS. It will also allow for the measurement of mass, parity, and coupling strength of this particle. [The experiment has been approved by the DESY directorate on January 11, 2007.

  13. Leptogenesis during Axion Relaxation after Inflation

    E-Print Network [OSTI]

    Schmitz, Kai

    2015-01-01T23:59:59.000Z

    In this talk, I present a novel and minimal alternative to thermal leptogenesis, which builds upon the assumption that the electroweak gauge bosons are coupled to an axion-like scalar field, as it is, for instance, the case in certain string compactifications. The motion of this axion-like field after the end of inflation generates an effective chemical potential for leptons and antileptons, which, in the presence of lepton number-violating scatterings mediated by heavy Majorana neutrinos, provides an opportunity for baryogenesis via leptogenesis. In contrast to thermal leptogenesis, the final baryon asymmetry turns out to be insensitive to the masses and CP-violating phases in the heavy neutrino sector. Moreover, the proposed scenario requires a reheating temperature of at least O(10^12) GeV and it is, in particular, consistent with heavy neutrino masses close the scale of grand unification. This talk was given in February 2015 at HPNP 2015 at Toyama University and is based on recent work (arXiv:1412.2043 [h...

  14. Cosmic axion background propagation in galaxies

    E-Print Network [OSTI]

    Day, Francesca V

    2015-01-01T23:59:59.000Z

    Many extensions of the Standard Model include axions or axion-like particles (ALPs). Here we study ALP to photon conversion in the magnetic field of the Milky Way and starburst galaxies. By modelling the effects of the coherent and random magnetic fields, the warm ionized medium and the warm neutral medium on the conversion process, we simulate maps of the conversion probability across the sky for a range of ALP energies. In particular, we consider a diffuse cosmic ALP background (CAB) analogous to the CMB, whose existence is suggested by string models of inflation. ALP-photon conversion of a CAB in the magnetic fields of galaxy clusters has been proposed as an explanation of the cluster soft X-ray excess. We therefore study the phenomenology and expected photon signal of CAB propagation in the Milky Way. We find that, for the CAB parameters required to explain the cluster soft X-ray excess, the photon flux from ALP-photon conversion in the Milky Way would be unobservably small. The ALP-photon conversion prob...

  15. Aspects of Axion Phenomenology in a slice of AdS_5

    E-Print Network [OSTI]

    Thomas Flacke; David Maybury

    2006-12-11T23:59:59.000Z

    Motivated by multi-throat considerations, we study the phenomenological implications of a bulk axion in a slice of AdS_5 with a large extra dimension: k~0.01 eV, kR > 1. In particular, we compare axion physics with a warped geometry to axions in flat compactifications. As in flat compactification scenarios, we find that the mass of the axion can become independent from the underlying Peccei-Quinn scale. Surprisingly, we find that in warped extra dimensions the axion's invisibility, cosmological viability, and basic phenomenology remain essentially unaltered in comparison to axions in flat compactifications.

  16. Search for solar chameleons and relic axions with CAST

    E-Print Network [OSTI]

    Cantatore, G; Zioutas, K

    2015-01-01T23:59:59.000Z

    New CAST research proposal covering the period 2015-2018 detailing motivations and novel techniques to search for solar Chameleons and new searches for relic Axions with the CAST dipole magnet

  17. Thermal axion production in the primordial quark-gluon plasma

    SciTech Connect (OSTI)

    Graf, Peter; Steffen, Frank Daniel [Max-Planck-Institut fuer Physik, Foehringer Ring 6, D-80805 Munich (Germany)

    2011-04-01T23:59:59.000Z

    We calculate the rate for thermal production of axions via scattering of quarks and gluons in the primordial quark-gluon plasma. To obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling, we use systematic field theoretical methods such as hard thermal loop resummation and the Braaten-Yuan prescription. The thermally produced yield, the decoupling temperature, and the density parameter are computed for axions with a mass below 10 meV. In this regime, with a Peccei-Quinn scale above 6x10{sup 8} GeV, the associated axion population can still be relativistic today and can coexist with the axion cold dark matter condensate.

  18. Thermal axion production in the primordial quark-gluon plasma

    E-Print Network [OSTI]

    Peter Graf; Frank Daniel Steffen

    2011-04-20T23:59:59.000Z

    We calculate the rate for thermal production of axions via scattering of quarks and gluons in the primordial quark-gluon plasma. To obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling, we use systematic field theoretical methods such as hard thermal loop resummation and the Braaten-Yuan prescription. The thermally produced yield, the decoupling temperature, and the density parameter are computed for axions with a mass below 10 meV. In this regime, with a Peccei-Quinn scale above 6x10^8 GeV, the associated axion population can still be relativistic today and can coexist with the axion cold dark matter condensate.

  19. Constraints on Axion Inflation from the Weak Gravity Conjecture

    E-Print Network [OSTI]

    Rudelius, Tom

    2015-01-01T23:59:59.000Z

    We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and `anti-alignment' of $C_4$ axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the `generalized' weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of $C_4$ axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from $D7$-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.

  20. Axion inflation and gravity waves in string theory

    SciTech Connect (OSTI)

    Kallosh, Renata; Sivanandam, Navin; Soroush, Masoud [Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, California 94305-4060 (United States)

    2008-02-15T23:59:59.000Z

    The majority of models of inflation in string theory predict an absence of measurable gravitational waves, r<<10{sup -3}. The most promising proposals for making string theoretic models that yield measurable tensor fluctuations involve axion fields with slightly broken shift symmetry. We consider such models in detail, with a particular focus on the N-flation scenario and on axion valley/natural inflation models. We find that in Calabi-Yau threefold compactifications with logarithmic Kaehler potentials K it appears to be difficult to meet the conditions required for axion inflation in the supergravity regime. However, in supergravities with an (approximately) quadratic shift-symmetric K, axion inflation may be viable. Such Kaehler potentials do arise in some string models, in specific limits of the moduli space. We describe the most promising classes of models; more detailed study will be required before one can conclude that working models exist.

  1. Axion cosmology with long-lived domain walls

    SciTech Connect (OSTI)

    Hiramatsu, Takashi [Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Kawasaki, Masahiro; Saikawa, Ken'ichi [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa City, Chiba 277-8582 (Japan); Sekiguchi, Toyokazu, E-mail: hiramatz@yukawa.kyoto-u.ac.jp, E-mail: kawasaki@icrr.u-tokyo.ac.jp, E-mail: saikawa@icrr.u-tokyo.ac.jp, E-mail: sekiguti@a.phys.nagoya-u.ac.jp [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya City, Aichi 464-8602 (Japan)

    2013-01-01T23:59:59.000Z

    We investigate the cosmological constraints on axion models where the domain wall number is greater than one. In these models, multiple domain walls attached to strings are formed, and they survive for a long time. Their annihilation occurs due to the effects of explicit symmetry breaking term which might be raised by Planck-scale physics. We perform three-dimensional lattice simulations and compute the spectra of axions and gravitational waves produced by long-lived domain walls. Using the numerical results, we estimated relic density of axions and gravitational waves. We find that the existence of long-lived domain walls leads to the overproduction of cold dark matter axions, while the density of gravitational waves is too small to observe at the present time. Combining the results with other observational constraints, we find that the whole parameter region of models are excluded unless an unacceptable fine-tuning exists.

  2. Localized Axion Photon States in a Strong Magnetic Field

    E-Print Network [OSTI]

    E. I. Guendelman

    2008-01-04T23:59:59.000Z

    We consider the axion field and electromagnetic waves with rapid time dependence, coupled to a strong time independent, asymptotically approaching a constant at infinity "mean" magnetic field, which takes into account the back reaction from the axion field and electromagnetic waves with rapid time dependence in a time averaged way. The direction of the self consistent mean field is orthogonal to the common direction of propagation of the axion and electromagnetic waves with rapid time dependence and parallel to the polarization of these electromagnetic waves. Then, there is an effective U(1) symmetry mixing axions and photons. Using the natural complex variables that this U(1) symmetry suggests we find localized planar soliton solutions. These solutions appear to be stable since they produce a different magnetic flux than the state with only a constant magnetic field, which we take as our "ground state". The solitons also have non trivial U(1) charge defined before, different from the uncharged vacuum.

  3. The spectral index and its running in axionic curvaton

    SciTech Connect (OSTI)

    Takahashi, Fuminobu, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

    2013-06-01T23:59:59.000Z

    We show that a sizable running spectral index suggested by the recent SPT data can be explained in the axionic curvaton model with a potential that consists of two sinusoidal contributions of different height and period. We find that the running spectral index is generically given by dn{sub s}/dln k ? 2?/?N (n{sub s}?1), where ?N is the e-folds during one period of modulations. In the string axiverse, axions naturally acquire a mass from multiple contributions, and one of the axions may be responsible for the density perturbations with a sizable running spectral index via the curvaton mechanism. We note that the axionic curvaton model with modulations can also accommodate the red-tilted spectrum with a negligible running, without relying on large-field inflation.

  4. In Search Of Axions: The CAST Experiment George K. Fanourakis

    E-Print Network [OSTI]

    Hudson, Hugh

    , Greece Abstract. The CERN Axion Solar Telescope (CAST) experiment uses a decommissioned LHC test magnet-Planck-Institut fur Extraterrestrische Physik, Garching, Germany, 6 Instituto de Fisica Nuclear y Altas Energias

  5. axion hot dark: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Axion hot dark matter bounds HEP - Phenomenology (arXiv) Summary: We derive cosmological limits on...

  6. axion cold dark: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Axions as Hot and Cold Dark Matter HEP - Phenomenology (arXiv) Summary: The presence of a hot dark matter component has...

  7. axion project incubation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    R; Melkumova, Elena; Tsov, Dmitry V. Gal'; Kerner, Richard 2003-01-01 3 Axion Dark Matter Searches HEP - Experiment (arXiv) Summary: Nearly all astrophysical and cosmological...

  8. axion cosmology revisited: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (arXiv) Summary: In axion quintessence, the cosmological era with an energy contrast in dark energy 0.1 < OmegaDE < 0.9 may represent a significant fraction of the universe's...

  9. Radio-loud Magnetars as Detectors for Axions and Axion-like Particles

    E-Print Network [OSTI]

    Doron Chelouche; Eduardo I. Guendelman

    2012-02-01T23:59:59.000Z

    We show that, by studying the arrival times of radio pulses from highly-magnetized transient beamed sources, it may be possible to detect light pseudo-scalar particles, such as axions and axion-like particles, whose existence could have considerable implications for the strong-CP problem of QCD as well as the dark matter problem in cosmology. Specifically, such light bosons may be detected with a much greater sensitivity, over a broad particle mass range, than is currently achievable by terrestrial experiments, and using indirect astrophysical considerations. The observable effect was discussed in Chelouche & Guendelman (2009), and is akin to the Stern-Gerlach experiment: the splitting of a photon beam naturally arises when finite coupling exists between the electro-magnetic field and the axion field. The splitting angle of the light beams linearly depends on the photon wavelength, the size of the magnetized region, and the magnetic field gradient in the transverse direction to the propagation direction of the photons. If radio emission in radio-loud magnetars is beamed and originates in regions with strong magnetic field gradients, then splitting of individual pulses may be detectable. We quantify the effect for a simplified model for magnetars, and search for radio beam splitting in the 2\\,GHz radio light curves of the radio loud magnetar XTE\\,J1810-197.

  10. Class of Einstein-Maxwell-dilaton-axion space-times

    SciTech Connect (OSTI)

    Matos, Tonatiuh; Miranda, Galaxia; Sanchez-Sanchez, Ruben; Wiederhold, Petra [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Distrito Federal (Mexico); Departamento de Fisica, Escuela Superior de Fisica y Matematicas del IPN, Edificio 9, 07738 Distrito Federal (Mexico); Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada del IPN, Legaria 694, 11500 Distrito Federal (Mexico); Departamento de Control Automatico, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Distrito Federal (Mexico)

    2009-06-15T23:59:59.000Z

    We use the harmonic maps ansatz to find exact solutions of the Einstein-Maxwell-dilaton-axion (EMDA) equations. The solutions are harmonic maps invariant to the symplectic real group in four dimensions Sp(4,R){approx}O(5). We find solutions of the EMDA field equations for the one- and two-dimensional subspaces of the symplectic group. Specially, for illustration of the method, we find space-times that generalize the Schwarzschild solution with dilaton, axion, and electromagnetic fields.

  11. Class of Einstein-Maxwell-Dilaton-Axion Space-Times

    E-Print Network [OSTI]

    Tonatiuh Matos; Galaxia Miranda; Ruben Sanchez-Sanchez; Petra Wiederhold

    2009-05-26T23:59:59.000Z

    We use the harmonic maps ansatz to find exact solutions of the Einstein-Maxwell-Dilaton-Axion (EMDA) equations. The solutions are harmonic maps invariant to the symplectic real group in four dimensions $Sp(4,\\Rreal)\\sim O(5)$. We find solutions of the EMDA field equations for the one and two dimensional subspaces of the symplectic group. Specially, for illustration of the method, we find space-times that generalise the Schwarzschild solution with dilaton, axion and electromagnetic fields.

  12. A First Look at Preheating after Axion Monodromy Inflation

    E-Print Network [OSTI]

    Moghaddam, Hossein Bazrafshan

    2015-01-01T23:59:59.000Z

    We take a first look at preheating after axion monodromy inflation, assuming a standard coupling between the inflaton field and a scalar matter field. We find that in spite of the fact that the oscillation of the inflaton about the field value which minimizes the potential is anharmonic, there is nevertheless a parametric resonance instability, and we determine the Floquet exponent which describes this instability as a function of the parameters of the axion monodromy potential.

  13. First Axion Results from the XENON100 Experiment

    E-Print Network [OSTI]

    The XENON100 Collaboration; E. Aprile; F. Agostini; M. Alfonsi; K. Arisaka; F. Arneodo; M. Auger; C. Balan; P. Barrow; L. Baudis; B. Bauermeister; A. Behrens; P. Beltrame; K. Bokeloh; A. Brown; E. Brown; S. Bruenner; G. Bruno; R. Budnik; J. M. R. Cardoso; A. P. Colijn; H. Contreras; J. P. Cussonneau; M. P. Decowski; E. Duchovni; S. Fattori; A. D. Ferella; W. Fulgione; F. Gao; M. Garbini; C. Geis; L. W. Goetzke; C. Grignon; E. Gross; W. Hampel; R. Itay; F. Kaether; G. Kessler; A. Kish; H. Landsman; R. F. Lang; M. Le Calloch; D. Lellouch; C. Levy; S. Lindemann; M. Lindner; J. A. M. Lopes; K. Lung; A. Lyashenko; S. Macmullin; T. Marrodan Undagoitia; J. Masbou; F. V. Massoli; D. Mayani Paras; A. J. Melgarejo Fernandez; Y. Meng; M. Messina; B. Miguez; A. Molinario; M. Murra; J. Naganoma; U. Oberlack; S. E. A. Orrigo; E. Pantic; R. Persiani; F. Piastra; J. Pienaar; G. Plante; N. Priel; S. Reichard; C. Reuter; A. Rizzo; S. Rosendahl; J. M. F. dos Santos; G. Sartorelli; S. Schindler; J. Schreiner; M. Schumann; L. Scotto Lavina; M. Selvi; P. Shagin; H. Simgen; A. Teymourian; D. Thers; A. Tiseni; G. Trinchero; O. Vitells; H. Wang; M. Weber; C. Weinheimer

    2014-08-27T23:59:59.000Z

    We present the first results of searches for axions and axion-like-particles with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$, has been tested by exploiting the axio-electric effect in liquid xenon. A profile likelihood analysis of 224.6 live days $\\times$ 34 kg exposure has shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \\times 10^{-12}$ (90% CL) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For axion-like-particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than $1 \\times 10^{-12}$ (90% CL) for masses between 5 and 10 keV/c$^2$.

  14. Conversion and Operation of CAST as a massive axion detector

    E-Print Network [OSTI]

    Elias, Nuno; Bordalo, Paula

    2010-01-01T23:59:59.000Z

    The axion was postulated after an elegant solution proposed by R. Peccei and H. Quinn to solve the strong CP problem of Quantum Chromodynamics. The CAST experiment searches for axions created in the core of the Sun. It uses an LHC superconducting prototype magnet to trigger the axion conversion into detectable X-ray photons. During its First Phase, with the magnetic field region kept under vacuum, CAST searched with high sensitivity for axion masses up to 0.02 eV/c2, for higher values the conversion coherence is lost. This thesis reflects the work that allows CAST to extend its search up to axion masses of 1 eV/c2. To restore the lost coherence a buffer gas is introduced in the magnet cold bores, such that the photon arising from the Primakoff conversion acquires an effective mass. The axion mass can be effectively scanned by fine tuning the gas density. The conversion of the experiment required the study, design and construction of a complex gas handling system to deal with a rare helium isotope, 3He. It rep...

  15. Axion Photon Oscillations From a "Particle-Antiparticle" View Point

    E-Print Network [OSTI]

    E. I. Guendelman

    2007-11-26T23:59:59.000Z

    We observe that it is very usefull to introduce a complex field for the axion photon system in an external magnetic field, when for example considered with the geometry of the experiments exploring axion photon mixing, where the real part is the axion and the imaginary part is the photon polarization that couples to the axion when the magnetic field is present. In the absence of the external magnetic field, the theory displays charge conjugation symmetry. In this formulation the axion and photon are the symmetric and antisymmetric combinations of particle and antiparticle (as defined from the complex field) respectively and they do not mix if the external magnetic field is set to zero. The magnetic field interaction is seen to be equivalent to first order to the interaction of the complex charged field with an external electric potential, where this ficticious "electric potential" is proportional to the external magnetic field. This interaction breaks the charge conjugation symmetry and therefore symmetric and antysymmetric combinations are not mantained in time. As a result one obtains axion photon mixing in the presence of an external magnetic field, a well known result understood in a different way.

  16. Reactor Vessel and Reactor Vessel Internals Segmentation at Zion Nuclear Power Station - 13230

    SciTech Connect (OSTI)

    Cooke, Conrad; Spann, Holger [Siempelkamp Nuclear Services: 5229 Sunset Blvd., (Suite M), West Columbia, SC, 29169 (United States)] [Siempelkamp Nuclear Services: 5229 Sunset Blvd., (Suite M), West Columbia, SC, 29169 (United States)

    2013-07-01T23:59:59.000Z

    Zion Nuclear Power Station (ZNPS) is a dual-unit Pressurized Water Reactor (PWR) nuclear power plant located on the Lake Michigan shoreline, in the city of Zion, Illinois approximately 64 km (40 miles) north of Chicago, Illinois and 67 km (42 miles) south of Milwaukee, Wisconsin. Each PWR is of the Westinghouse design and had a generation capacity of 1040 MW. Exelon Corporation operated both reactors with the first unit starting production of power in 1973 and the second unit coming on line in 1974. The operation of both reactors ceased in 1996/1997. In 2010 the Nuclear Regulatory Commission approved the transfer of Exelon Corporation's license to ZionSolutions, the Long Term Stewardship subsidiary of EnergySolutions responsible for the decommissioning of ZNPS. In October 2010, ZionSolutions awarded Siempelkamp Nuclear Services, Inc. (SNS) the contract to plan, segment, remove, and package both reactor vessels and their respective internals. This presentation discusses the tools employed by SNS to remove and segment the Reactor Vessel Internals (RVI) and Reactor Vessels (RV) and conveys the recent progress. SNS's mechanical segmentation tooling includes the C-HORCE (Circumferential Hydraulically Operated Cutting Equipment), BMT (Bolt Milling Tool), FaST (Former Attachment Severing Tool) and the VRS (Volume Reduction Station). Thermal segmentation of the reactor vessels will be accomplished using an Oxygen- Propane cutting system. The tools for internals segmentation were designed by SNS using their experience from other successful reactor and large component decommissioning and demolition (D and D) projects in the US. All of the designs allow for the mechanical segmentation of the internals remotely in the water-filled reactor cavities. The C-HORCE is designed to saw seven circumferential cuts through the Core Barrel and Thermal Shield walls with individual thicknesses up to 100 mm (4 inches). The BMT is designed to remove the bolts that fasten the Baffle Plates to the Baffle Former Plates. The FaST is designed to remove the Baffle Former Plates from the Core Barrel. The VRS further volume reduces segmented components using multiple configurations of the 38i and horizontal reciprocating saws. After the successful removal and volume reduction of the Internals, the RV will be segmented using a 'First in the US' thermal cutting process through a co-operative effort with Siempelkamp NIS Ingenieurgesellschaft mbH using their experience at the Stade NPP and Karlsruhe in Germany. SNS mobilized in the fall of 2011 to commence execution of the project in order to complete the RVI segmentation, removal and packaging activities for the first unit (Unit 2) by end of the 2012/beginning 2013 and then mobilize to the second unit, Unit 1. Parallel to the completion of the segmentation of the reactor vessel internals at Unit 1, SNS will segment the Unit 2 pressure vessel and at completion move to Unit 1. (authors)

  17. Observational constraints on gauge field production in axion inflation

    SciTech Connect (OSTI)

    Meerburg, P.D. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08540 (United States); Pajer, E., E-mail: meerburg@princeton.edu, E-mail: enrico.pajer@gmail.com [Department of Physics, Princeton University, Princeton, NJ 08544 (United States)

    2013-02-01T23:59:59.000Z

    Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of the observational consequences are directly related to this symmetry and hence are correlated. Large tensor modes can be accompanied by the observable effects of a the shift-symmetric coupling ?F F-tilde to a gauge field. During inflation this coupling leads to a copious production of gauge quanta and consequently a very distinct modification of the primordial curvature perturbations. In this work we compare these predictions with observations. We find that the leading constraint on the model comes from the CMB power spectrum when considering both WMAP 7-year and ACT data. The bispectrum generated by the non-Gaussian inverse-decay of the gauge field leads to a comparable but slightly weaker constraint. There is also a constraint from ?-distortion using TRIS plus COBE/FIRAS data, but it is much weaker. Finally we comment on a generalization of the model to massive gauge fields. When the mass is generated by some light Higgs field, observably large local non-Gaussianity can be produced.

  18. Bifid Throats for Axion Monodromy Inflation

    E-Print Network [OSTI]

    Retolaza, Ander; Westphal, Alexander

    2015-01-01T23:59:59.000Z

    We construct a simple explicit local geometry providing a `bifid throat' for 5-brane axion monodromy. A bifid throat is a throat that splits into two daughter throats in the IR, containing a homologous 2-cycle family reaching down into each daughter throat. Our example consists of a deformed \\mathbb{Z}_3 \\times \\mathbb{Z}_2 orbifold of the conifold, which provides us with an explicit holographic dual of the bifid throat including D3-branes and fractional 5-branes at the toric singularities of our setup. Having the holographic description in terms of the dual gauge theory allows us to address the effect of 5-brane-antibrane pair backreaction including the warping effects. This leads to the size of the backreaction being small and controllable after imposing proper normalization of the inflaton potential and hence the warping scales.

  19. Dilaton and axion bremsstrahlung from collisions of cosmic (super)strings

    E-Print Network [OSTI]

    E. Yu. Melkumova; D. V. Gal'tsov; K. Salehi

    2006-12-26T23:59:59.000Z

    We calculate dilaton and axion radiation generated in the collision of two straight initially unexcited strings and give a rough cosmological estimate of dilaton and axion densities produced via this mechanism in the early universe.

  20. Internal combustion engine system having a power turbine with a broad efficiency range

    DOE Patents [OSTI]

    Whiting, Todd Mathew; Vuk, Carl Thomas

    2010-04-13T23:59:59.000Z

    An engine system incorporating an air breathing, reciprocating internal combustion engine having an inlet for air and an exhaust for products of combustion. A centripetal turbine receives products of the combustion and has a housing in which a turbine wheel is rotatable. The housing has first and second passages leading from the inlet to discrete, approximately 180.degree., portions of the circumference of the turbine wheel. The passages have fixed vanes adjacent the periphery of the turbine wheel and the angle of the vanes in one of the passages is different than those in the other so as to accommodate different power levels providing optimum approach angles between the gases passing the vanes and the blades of the turbine wheel. Flow through the passages is controlled by a flapper valve to direct it to one or the other or both passages depending upon the load factor for the engine.

  1. GammeV: Fermilab axion-like particle photon regeneration results

    SciTech Connect (OSTI)

    Wester, William; /Fermilab

    2008-09-01T23:59:59.000Z

    GammeV is an axion-like particle photon regeneration experiment conducted at Fermilab that employs the light shining through a wall technique. They obtain limits on the coupling of a photon to an axion-like particle that extend previous limits for both scalar and pseudoscalar axion-like particles in the milli-eV mass range. They are able to exclude the axion-like particle interpretation of the anomalous PVLAS 2006 result by more than 5 standard deviations.

  2. Resonantly Enhanced Axion-Photon Regeneration P. Sikivie,1,2

    E-Print Network [OSTI]

    Tanner, David B.

    Resonantly Enhanced Axion-Photon Regeneration P. Sikivie,1,2 D. B. Tanner,1 and Karl van Bibber3 1 search for the axion, or axionlike particles, may be resonantly enhanced by employing matched Fabry-Perot optical cavities encompassing both the axion production and conversion magnetic field regions. Compared

  3. Searching for an Axion-like Particle at the Large Hadron Collider

    E-Print Network [OSTI]

    Claudio Coriano; Marco Guzzi; Antonio Mariano

    2009-05-27T23:59:59.000Z

    Axion-like particles are an important part of the spectrum of anomalous gauge theories involving modified mechanisms of cancellation of the gauge anomalies. Among these are intersecting brane models, which are characterized by the presence of one physical axion. We overview a recent study of their supersymmetric construction and some LHC studies of the productions rates for a gauged axion.

  4. Computational Design of Axion Insulators Based on 5d Spinel Compounds Xiangang Wan,1

    E-Print Network [OSTI]

    Savrasov, Sergej Y.

    Computational Design of Axion Insulators Based on 5d Spinel Compounds Xiangang Wan,1 Ashvin electronic properties, in particular, a large magnetoelectric coupling charac- teristic of axion of the axion electrodynamics parameter ¼ [10,11]. When time reversal symmetry as well as spatial symme- tries

  5. Volume 125B, number 2,3 PHYSICS LETTERS 26 May 1983 DYON-AXION DYNAMICS

    E-Print Network [OSTI]

    Preskill, John

    Volume 125B, number 2,3 PHYSICS LETTERS 26 May 1983 DYON-AXION DYNAMICS Willy FISCHLER 1 Department between magnetic monopoles and axions induced by the Witten effect, and discuss the cosmo- logical implications of monopole-axion interactions. The discovery by Witten [1] that a magnetic mono- pole of minimal

  6. Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1

    E-Print Network [OSTI]

    Durrer, Ruth

    Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1 and Mairi Sakellariadou the energy spectra for massless Kalb-Ramond axions in four-dimensional anisotropic string cosmological models). In contrast, the axion energy spectra were found to be diverging at large scales, red spectra, leading to very

  7. Searching for axion-like-particles in the sky C. Burragea

    E-Print Network [OSTI]

    1 Searching for axion-like-particles in the sky C. Burragea a Theory Group, Deutsches Elektronen it behaves as an Axion-Like-Particle (ALP). ALPs mix with photons in the presence of magnetic fields of a coupling between the scalar field and photons. Fields with such couplings are generically known as Axion

  8. Axion-induced effects in atoms, molecules and nuclei: Parity nonconservation, anapole moments, electric dipole moments, and spin-gravity and spin-axion momentum couplings

    E-Print Network [OSTI]

    Y. V. Stadnik; V. V. Flambaum

    2015-02-24T23:59:59.000Z

    We show that the interaction of an axion field, or in general a pseudoscalar field, with the axial-vector current generated by an electron through a derivative-type coupling can give rise to a time-dependent mixing of opposite-parity states in atomic and molecular systems. Likewise, the analogous interaction of an axion field with the axial-vector current generated by a nucleon can give rise to time-dependent mixing of opposite-parity states in nuclear systems. This mixing can induce oscillating electric dipole moments, oscillating parity non-conservation effects and oscillating anapole moments in such systems. By adjusting the energy separation between the opposite-parity states of interest to match the axion mass energy, axion-induced experimental observables can be enhanced by many orders of magnitude. Oscillating atomic electric dipole moments can also be generated by axions through hadronic mechanisms, namely the P,T-violating nucleon-nucleon interaction and through the axion-induced electric dipole moments of valence nucleons, which comprise the nuclei. The axion field is modified by the Earth's gravitational field. The interaction of the spin of either an electron or nucleon with this modified axion field leads to axion-induced observable effects. These effects, which are of the form $\\mathbf{g} \\cdot \\mathbf{\\sigma}$, differ from the axion-wind effect, which has the form $\\mathbf{p}_{\\textrm{a}} \\cdot \\mathbf{\\sigma}$.

  9. Volume 120B, number 1,2,3 PHYSICSLETTERS 6 January 1983 A COSMOLOGICAL BOUND ON THE INVISIBLE AXION

    E-Print Network [OSTI]

    Columbia University

    Volume 120B, number 1,2,3 PHYSICSLETTERS 6 January 1983 A COSMOLOGICAL BOUND ON THE INVISIBLE AXION The production of axions in the early universe is studied. Axion models which break the U(1)pQ symmetry above 1012 GeV are found to produce an unacceptably large axion energy density. The absence of CP violation

  10. Volume 120B, number 1,2,3 PHYSICS LETTERS 6 January 1983 COSMOLOGY OF THE INVISIBLE AXION

    E-Print Network [OSTI]

    Preskill, John

    Volume 120B, number 1,2,3 PHYSICS LETTERS 6 January 1983 COSMOLOGY OF THE INVISIBLE AXION John with an invisible axion, unrelated to the domain wall problem. Because the axion is very weakly coupled, the energy density stored in the oscillationsof the classical axion field does not dissipate rapidly;it exceeds

  11. Constraining axion by polarized prompt emission from gamma ray bursts

    E-Print Network [OSTI]

    A. Rubbia; A. S. Sakharov

    2007-08-21T23:59:59.000Z

    A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of invisible axion. The axionic induced dichroism of gamma rays at different energies should cause a misalignment of the polarization plane for higher energy events relative to that one for lower energies events resulting in the loss of statistics needed to form a pattern of the polarization signal to be recognized in a detector. According to this, any evidence of polarized gamma rays coming from an object with extended magnetic field could be interpreted as a constraint on the existence of the invisible axion for a certain parameter range. Based on reports of polarized MeV emission detected in several GRBs we derive a constraint on the axion-photon coupling. This constraint $\\g_{a\\gamma\\gamma}\\le 2.2\\cdot 10^{-11} {\\rm GeV^{-1}}$ calculated for the axion mass $m_a=10^{-3} {\\rm eV}$ is competitive with the sensitivity of CAST and becomes even stronger for lower masses.

  12. New solar axion search in CAST with $^4$He filling

    E-Print Network [OSTI]

    Arik, M; Barth, K; Belov, A; Brauninger, H; Bremer, J; Burwitz, V; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Dermenev, A; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Galan, J; Garcia, J A; Gardikiotis, A.; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Marzoa, M Gomez; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; K.Jakovcic; Karuza, M; Kavuk, M; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Luzon, G; Neff, S; Niinikoski, T; Nordt, A; Ortega, I; Papaevangelou, T; Pivovaroff, M .J; Raffelt, G; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Solanki, S K; Stewart, L; Tomas, A; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2015-01-01T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) searches for $a\\to\\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the X-ray refractive mass $m_\\gamma$ to the axion search mass $m_a$. After the vacuum phase (2003--2004), which is optimal for $m_a\\lesssim0.02$ eV, we used $^4$He in 2005--2007 to cover the mass range of 0.02--0.39 eV and $^3$He in 2009--2011 to scan from 0.39--1.17 eV. After improving the detectors and shielding, we returned to $^4$He in 2012 to investigate a narrow $m_a$ range around 0.2 eV ("candidate setting" of our earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with $^4$He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to $g_{a\\gamma}< 1.47\\times10^{-10} {\\rm GeV}^{-1}$ (95% C.L.), depending on the pressure settings. Since 2013, we have returned to vacuum and aim for a s...

  13. Axion monodromy in a model of holographic gluodynamics

    E-Print Network [OSTI]

    Sergei Dubovsky; Albion Lawrence; Matthew M. Roberts

    2011-11-10T23:59:59.000Z

    The low energy field theory for N type IIA D4-branes at strong 't Hooft coupling, wrapped on a circle with antiperiodic boundary conditions for fermions, is known to have a vacuum energy which depends on the $\\theta$ angle for the gauge fields, and which is a multivalued function of this angle. This gives a field-theoretic realization of "axion monodromy" for a nondynamical axion. We construct the supergravity solution dual to the field theory in the metastable state which is the adiabatic continuation of the vacuum to large values of $\\theta$. We compute the energy of this state and show that it initially rises quadratically and then flattens out. We show that the glueball mass decreases with $\\theta$, becoming much lower than the 5d KK scale governing the UV completion of this model. We construct two different classes of domain walls interpolating between adjacent vacua. We identify a number of instability modes -- nucleation of domain walls, bulk Casimir forces, and condensation of tachyonic winding modes in the bulk -- which indicate that the metastable branch eventually becomes unstable. Finally, we discuss two phenomena which can arise when the axion is dynamical; axion-driven inflation, and axion strings.

  14. New solar axion search in CAST with $^4$He filling

    E-Print Network [OSTI]

    M. Arik; S. Aune; K. Barth; A. Belov; H. Bräuninger; J. Bremer; V. Burwitz; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; E. Da Riva; T. Dafni; M. Davenport; A. Dermenev; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; J. Galán; J. A. García; A. Gardikiotis; J. G. Garza; E. N. Gazis; T. Geralis; E. Georgiopoulou; I. Giomataris; S. Gninenko; M. Gómez Marzoa; M. D. Hasinoff; D. H. H. Hoffmann; F. J. Iguaz; I. G. Irastorza; J. Jacoby; K. Jakov?i?; M. Karuza; M. Kavuk; M. Kr?mar; M. Kuster; B. Laki?; J. M. Laurent; A. Liolios; A. Ljubi?i?; G. Luzón; S. Neff; T. Niinikoski; A. Nordt; I. Ortega; T. Papaevangelou; M. J. Pivovaroff; G. Raffelt A. Rodríguez; M. Rosu; J. Ruz; I. Savvidis; I. Shilon; S. K. Solanki; L. Stewart; A. Tomás; T. Vafeiadis; J. Villar; J. K. Vogel; S. C. Yildiz; K. Zioutas

    2015-06-11T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) searches for $a\\to\\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the X-ray refractive mass $m_\\gamma$ to the axion search mass $m_a$. After the vacuum phase (2003--2004), which is optimal for $m_a\\lesssim0.02$ eV, we used $^4$He in 2005--2007 to cover the mass range of 0.02--0.39 eV and $^3$He in 2009--2011 to scan from 0.39--1.17 eV. After improving the detectors and shielding, we returned to $^4$He in 2012 to investigate a narrow $m_a$ range around 0.2 eV ("candidate setting" of our earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with $^4$He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to $g_{a\\gamma}< 1.47\\times10^{-10} {\\rm GeV}^{-1}$ (95% C.L.), depending on the pressure settings. Since 2013, we have returned to vacuum and aim for a significant increase in sensitivity.

  15. Improved cosmological bound on the thermal axion mass

    SciTech Connect (OSTI)

    Melchiorri, Alessandro; Mena, Olga [INFN Sez. di Roma, Dipartimento di Fisica, Universita di Roma 'La Sapienza', P.le A. Moro, 5, I-00185 Rome (Italy); Slosar, Anze [Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Road, OX3RH1, Oxford (United Kingdom); Faculty of Mathematics and Physics, University of Ljubljana (Slovenia)

    2007-08-15T23:59:59.000Z

    Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous cosmological bounds on the axion mass m{sub a} in the so-called hadronic axion window. We obtain a limit on the axion mass m{sub a}<0.42 eV at the 95% C.L. (m{sub a}<0.72 eV at the 99% C.L.). A novel aspect of the analysis presented here is the inclusion of massive neutrinos and how they may affect the bound on the axion mass. If neutrino masses belong to an inverted hierarchy scheme, for example, the above constraint is improved to m{sub a}<0.38 eV at the 95% C.L. (m{sub a}<0.67 eV at the 99% C.L.). Future data from experiments as CAST will provide a direct test of the cosmological bound.

  16. New solar axion search in CAST with $^4$He filling

    E-Print Network [OSTI]

    M. Arik; S. Aune; K. Barth; A. Belov; H. Bräuninger; J. Bremer; V. Burwitz; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; E. Da Riva; T. Dafni; M. Davenport; A. Dermenev; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; J. Galán; J. A. García; A. Gardikiotis; J. G. Garza; E. N. Gazis; T. Geralis; E. Georgiopoulou; I. Giomataris; S. Gninenko; M. Gómez Marzoa; M. D. Hasinoff; D. H. H. Hoffmann; F. J. Iguaz; I. G. Irastorza; J. Jacoby; K. Jakov?i?; M. Karuza; M. Kavuk; M. Kr?mar; M. Kuster; B. Laki?; J. M. Laurent; A. Liolios; A. Ljubi?i?; G. Luzón; S. Neff; T. Niinikoski; A. Nordt; I. Ortega; T. Papaevangelou; M. J. Pivovaroff; G. Raffelt A. Rodríguez; M. Rosu; J. Ruz; I. Savvidis; I. Shilon; S. K. Solanki; L. Stewart; A. Tomás; T. Vafeiadis; J. Villar; J. K. Vogel; S. C. Yildiz; K. Zioutas

    2015-03-02T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) searches for $a\\to\\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the X-ray refractive mass $m_\\gamma$ to the axion search mass $m_a$. After the vacuum phase (2003--2004), which is optimal for $m_a\\lesssim0.02$ eV, we used $^4$He in 2005--2007 to cover the mass range of 0.02--0.39 eV and $^3$He in 2009--2011 to scan from 0.39--1.17 eV. After improving the detectors and shielding, we returned to $^4$He in 2012 to investigate a narrow $m_a$ range around 0.2 eV ("candidate setting" of our earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with $^4$He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to $g_{a\\gamma}< 1.47\\times10^{-10} {\\rm GeV}^{-1}$ (95% C.L.), depending on the pressure settings. Since 2013, we have returned to vacuum and aim for a significant increase in sensitivity.

  17. International Energy Workshop, Cape Town, June 19-21, 2012 Power system and Carbon capture under Climate policy

    E-Print Network [OSTI]

    Boyer, Edmond

    International Energy Workshop, Cape Town, June 19-21, 2012 Power system and Carbon capture under-term modelling, TIAM-FR, Climate change, CO2 mitigation, Carbon Capture and Storage (CCS), Water impact 1 `readiness' of advanced technologies, in particular the industrial scale of carbon capture and storage (CCS

  18. A SQUID-based microwave cavity search for dark-matter axions

    SciTech Connect (OSTI)

    Asztalos, S J; Carosi, G; Hagmann, C; Kinion, D; van Bibber, K; Hotz, M; Rosenberg, L; Rybka, G; Hoskins, J; Hwang, J; Sikivie, P; Tanner, D B; Bradley, R; Clarke, J

    2009-10-21T23:59:59.000Z

    Axions in the {mu}eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. The first result from such an axion search using a superconducting first-stage amplifier (SQUID) is reported. The SQUID amplifier, replacing a conventional GaAs field-effect transistor amplifier, successfully reached axion-photon coupling sensitivity in the band set by present axion models and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

  19. Iso-curvature fluctuations through axion trapping by cosmic string wakes

    E-Print Network [OSTI]

    Biswanath Layek

    2005-03-07T23:59:59.000Z

    We consider wake-like density fluctuations produced by cosmic strings at the quark-hadron transition in the early universe. We show that low momentum axions which are produced through the radiation from the axionic string at an earlier stage, may get trapped inside these wakes due to delayed hadronization in these overdense regions. As the interfaces, bordering the wakes, collapse, the axions pick-up momentum from the walls and finally leave the wake regions. These axions thus can produce large scale iso-curvature fluctuations. We have calculated the detailed profile of these axionic density fluctuations and discuss its astrophysical consequences.

  20. An invisible axion model with controlled FCNCs at tree level

    E-Print Network [OSTI]

    Alejandro Celis; Javier Fuentes-Martin; Hugo Serodio

    2015-01-04T23:59:59.000Z

    We derive the necessary conditions to build a class of invisible axion models with Flavor Changing Neutral Currents at tree-level controlled by the fermion mixing matrices and present an explicit model implementation. A horizontal Peccei-Quinn symmetry provides a solution to the strong CP problem via the Peccei-Quinn mechanism and predicts a cold dark mater candidate, the invisible axion or familon. The smallness of active neutrino masses can be explained via a type I seesaw mechanism, providing a dynamical origin for the heavy seesaw scale. The possibility to avoid the domain wall problem stands as one of the most interesting features of the type of models considered. Experimental limits relying on the axion-photon coupling, astrophysical considerations and familon searches in rare kaon and muon decays are discussed.

  1. Gamma-ray bursts, axion emission and string theory dilaton

    E-Print Network [OSTI]

    O. Bertolami

    1999-01-14T23:59:59.000Z

    The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has been recently confirmed by the observed correlation between the burst of April 25, 1998 and the supernova SN1998bw. We argue that the axion convertion into photons can be more efficient if one considers the coupling between an intermediate scale axion and the string theory dilaton along with the inclusion of string loops. We also discuss the way dilaton dynamics may allow for a more effective energy exchange with electromagnetic radiation in the expansion process of fireballs.

  2. Born-Infeld Axion-Dilaton Electrodynamics and Electromagnetic Confinement

    E-Print Network [OSTI]

    D. A. Burton; T. Dereli; R. W. Tucker

    2011-08-16T23:59:59.000Z

    A generalization of Born-Infeld non-linear vacuum electrodynamics involving axion and dilaton fields is constructed with couplings dictated by electromagnetic duality and SL(2,R) symmetries in the weak field limit. Besides the Newtonian gravitational constant the model contains a single fundamental coupling parameter b0. In the absence of axion and dilaton interactions it reduces, in the limit as b0 tends to infinity, to Maxwell's linear vacuum theory while for finite b0 it reduces to the original Born-Infeld model. The spherically symmetric static sector of the theory is explored in a background Minkowski spacetime where numerical evidence suggests the existence of axion-dilaton bound states possessing confined electric flux.

  3. Axion-Dilaton Domain Walls and Fake Supergravity

    E-Print Network [OSTI]

    Julian Sonner; Paul K. Townsend

    2007-05-07T23:59:59.000Z

    Dynamical systems methods are used to investigate domain-wall solutions of a two-parameter family of models in which gravity is coupled to an axion, and to a dilaton with an exponential potential of either sign. A complete global analysis is presented for (i) constant axion and (ii) flat walls, including a study of bifurcations and a new exact domain-wall solution with non-constant axion. We reconsider `fake supergravity' issues in light of these results. We show, by example, how domain walls determine multi-valued superpotentials that branch at stationary points that are not stationary points of the potential, and we apply this result to potentials with anti-de Sitter vacua. We also show by example that `adapted' truncation to a single-scalar model is sometimes inconsistent, and we propose a `generalized' fake supergravity formalism that applies in some such cases.

  4. Cosmological bounds on sub-MeV mass axions

    SciTech Connect (OSTI)

    Cadamuro, Davide; Raffelt, Georg; Redondo, Javier [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Hannestad, Steen, E-mail: cadamuro@mppmu.mpg.de, E-mail: sth@phys.au.dk, E-mail: raffelt@mppmu.mpg.de, E-mail: redondo@mppmu.mpg.de [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

    2011-02-01T23:59:59.000Z

    Axions with mass m{sub a} ?> 0.7 eV are excluded by cosmological precision data because they provide too much hot dark matter. While for m{sub a} ?> 20 eV the a ? 2? lifetime drops below the age of the universe, we show that the cosmological exclusion range can be extended to 0.7eV ?< m{sub a} ?< 300 keV, primarily by the cosmic deuterium abundance: axion decays would strongly modify the baryon-to-photon ratio at BBN relative to the one at CMB decoupling. Additional arguments include neutrino dilution relative to photons by axion decays and spectral CMB distortions. Our new cosmological constraints complement stellar-evolution and laboratory bounds.

  5. Widening the Axion Window via Kinetic and St\\"uckelberg Mixings

    E-Print Network [OSTI]

    Shiu, Gary; Ye, Fang

    2015-01-01T23:59:59.000Z

    We point out that kinetic and St\\"uckelberg mixings that are generically present in the low energy effective action of axions can significantly widen the window of axion decay constants. We show that an effective super-Planckian decay constant can be obtained even when the axion kinetic matrix has only sub-Planckian entries. Our minimal model involves only two axions, a St\\"uckelberg U(1) and a modest rank instanton generating non-Abelian group. Below the mass of the St\\"uckelberg U(1), there is only a single axion with a non-perturbatively generated potential. In contrast to previous approaches, the enhancement of the axion decay constant is not tied to the number of degrees of freedom introduced. We also discuss how kinetic mixings can lower the decay constant to the desired axion dark matter window. String theory embeddings of this scenario and their phenomenological features are briefly discussed.

  6. Mixed axion/neutralino cold dark matter in supersymmetric models

    SciTech Connect (OSTI)

    Baer, Howard; Lessa, Andre; Rajagopalan, Shibi; Sreethawong, Warintorn, E-mail: baer@nhn.ou.edu, E-mail: lessa@nhn.ou.edu, E-mail: shibi@nhn.ou.edu, E-mail: wstan@nhn.ou.edu [Dept. of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2011-06-01T23:59:59.000Z

    We consider supersymmetric (SUSY) models wherein the strong CP problem is solved by the Peccei-Quinn (PQ) mechanism with a concommitant axion/axino supermultiplet. We examine R-parity conserving models where the neutralino is the lightest SUSY particle, so that a mixture of neutralinos and axions serve as cold dark matter (a Z-tilde {sub 1} CDM). The mixed a Z-tilde {sub 1} CDM scenario can match the measured dark matter abundance for SUSY models which typically give too low a value of the usual thermal neutralino abundance, such as models with wino-like or higgsino-like dark matter. The usual thermal neutralino abundance can be greatly enhanced by the decay of thermally-produced axinos (ã) to neutralinos, followed by neutralino re-annihilation at temperatures much lower than freeze-out. In this case, the relic density is usually neutralino dominated, and goes as ? (f{sub a}/N)/m{sub ã}{sup 3/2}. If axino decay occurs before neutralino freeze-out, then instead the neutralino abundance can be augmented by relic axions to match the measured abundance. Entropy production from late-time axino decays can diminish the axion abundance, but ultimately not the neutralino abundance. In a Z-tilde {sub 1} CDM models, it may be possible to detect both a WIMP and an axion as dark matter relics. We also discuss possible modifications of our results due to production and decay of saxions. In the appendices, we present expressions for the Hubble expansion rate and the axion and neutralino relic densities in radiation, matter and decaying-particle dominated universes.

  7. Review of the Shoreham Nuclear Power Station Probabilistic Risk Assessment: internal events and core damage frequency

    SciTech Connect (OSTI)

    Ilberg, D.; Shiu, K.; Hanan, N.; Anavim, E.

    1985-11-01T23:59:59.000Z

    A review of the Probabilistic Risk Assessment of the Shoreham Nuclear Power Station was conducted with the broad objective of evaluating its risks in relation to those identified in the Reactor Safety Study (WASH-1400). The scope of the review was limited to the ''front end'' part, i.e., to the evaluation of the frequencies of states in which core damage may occur. Furthermore, the review considered only internally generated accidents, consistent with the scope of the PRA. The review included an assessment of the assumptions and methods used in the Shoreham study. It also encompassed a reevaluation of the main results within the scope and general methodological framework of the Shoreham PRA, including both qualitative and quantitative analyses of accident initiators, data bases, and accident sequences which result in initiation of core damage. Specific comparisons are given between the Shoreham study, the results of the present review, and the WASH-1400 BWR, for the core damage frequency. The effect of modeling uncertainties was considered by a limited sensitivity study so as to show how the results would change if other assumptions were made. This review provides an independently assessed point value estimate of core damage frequency and describes the major contributors, by frontline systems and by accident sequences. 17 figs., 81 tabs.

  8. Parametric Resonance and Dark Matter Axion-Like Particles

    E-Print Network [OSTI]

    Arza, Ariel; Gamboa, Jorge

    2015-01-01T23:59:59.000Z

    We study the local effects of an external time-dependent magnetic field on axion-like particles assuming they are all the dark matter of the universe. We find that under suitable conditions the amplitude of the dark matter field can resonate parametrically. The resonance depends on the velocity of the axion-like particles and scales quadratically with the strength} of the external magnetic field, $\\frac{\\rho}{\\rho_{DM}} \\sim {B_0}^3$. By considering typical experimental benchmark values, we find the resonance could amplify around two orders of magnitude the local energy density stored in the dark matter condensate.

  9. Axion arising from warped extra-dimensional gauge fields

    SciTech Connect (OSTI)

    Burnier, Y.; Kuehnel, F. [Department of Physics and Astronomy, SUNY, Stony Brook, New York 11794-3800 (United States); Arnold Sommerfeld Center, Ludwig-Maximilians University, Theresienstr. 37, 80333 Muenchen (Germany)

    2011-06-01T23:59:59.000Z

    We present a connection between two known solutions to the strong-CP problem: the standard introduction of axions and the extra-dimensional one, relying on topological arguments. Using an equivalent lower-dimensional setup with a warped extra dimension but without adding any new fields, it is shown that an additional light degree of freedom appears. Like an axion, it couples to the topological charge density via fermionic loop corrections. Its decay constant is related to the geometry of the extra dimension and is suppressed by the warping scale.

  10. Observable dark radiation from cosmologically safe QCD axion

    E-Print Network [OSTI]

    Kawasaki, Masahiro; Yanagida, Tsutomu T

    2015-01-01T23:59:59.000Z

    We propose a QCD axion model that avoids the cosmological domain wall problem, introducing a global SU(3)_f family symmetry to which we embed the unwanted PQ discrete symmetry. The spontaneous breaking of SU(3)_f and PQ symmetry predicts eight NG bosons as well as axion, all of which contribute to dark radiation in the Universe. The derivation from the standard model prediction of dark radiation can be observed by future observations of CMB fluctuations. Our model also predicts a sizable exotic kaon decay rate, which is marginally consistent with the present collider data and would be tested by future collider experiments.

  11. Axions, strong and weak CP, and KNP inflation

    E-Print Network [OSTI]

    Kim, Jihn E

    2015-01-01T23:59:59.000Z

    I review the ideas leading to the QCD axion and also comment on the Jarlskog determinant describing the observed weak CP violation, and the axion-related Kim-Nilles-Peloso inflation. All of these use pseudoscalars, and the underlying principle is the discrete gauge symmetry either in the bottom-up or top-down approaches. Here, the effects of gravity are required to be unimportant in the low energy effective theory. String compactification is safe from the gravity spoil of global symmetries and some examples from string compactification are commented.

  12. A keV String Axion from High Scale Supersymmetry

    E-Print Network [OSTI]

    Brian Henning; John Kehayias; Hitoshi Murayama; David Pinner; Tsutomu T. Yanagida

    2015-03-20T23:59:59.000Z

    Various theoretical and experimental considerations motivate models with high scale supersymmetry breaking. While such models may be difficult to test in colliders, we propose looking for signatures at much lower energies. We show that a keV line in the X-ray spectrum of galaxy clusters (such as the recently disputed 3.5 keV observation) can have its origin in a universal string axion coupled to a hidden supersymmetry breaking sector. A linear combination of the string axion and an additional axion in the hidden sector remains light, obtaining a mass of order 10 keV through supersymmetry breaking dynamics. In order to explain the X-ray line, the scale of supersymmetry breaking must be about $10^{11-12}$ GeV. This motivates high scale supersymmetry as in pure gravity mediation or minimal split supersymmetry and is consistent with all current limits. Since the axion mass is controlled by a dynamical mass scale, this mass can be much higher during inflation, avoiding isocurvature (and domain wall) problems associated with high scale inflation. In an appendix we present a mechanism for dilaton stabilization that additionally leads to $\\mathcal{O}(1)$ modifications of the gaugino mass from anomaly mediation.

  13. Gauge/Gravity Theory with Running Dilaton and Running Axion

    E-Print Network [OSTI]

    Girma Hailu

    2007-12-27T23:59:59.000Z

    We present a new gauge/gravity duality construction of the Klebanov-Strassler throat which takes corrections to the anomalous mass dimension proposed in [1] into account on the gauge theory side and both the dilaton and the axion run on the gravity side. The corresponding supergravity solutions are found using equations for type IIB flows with N=1 supersymmetry obtained in [2]. We find that magnetic couplings of the axion to D7-branes filling 4-d spacetime and wrapping 4-cycles at locations of duality transitions and invisible Dirac 8-branes whose worldvolume emanates from the worldvolume of the D7-branes are the sources for the runnings of the dilaton and the axion. Our construction provides the first explicit example of a gauge/gravity duality mapping with a running dilaton or a running axion which is an important component towards finding gravity duals to gauge theories with physically more interesting renormalization group flows such as pure confining gauge theories in four dimensions. The D7-branes also serve as gravitational source for Seiberg duality transitions. The supergravity background has distinct features which could be useful for constructing cosmological models and studying possibilities for probing stringy signatures from the early universe.

  14. Guide to authorization procedures for the international export of electricity and electric power lines crossing international borders

    SciTech Connect (OSTI)

    None

    1980-11-01T23:59:59.000Z

    The Economic Regulatory Administration (ERA) has prepared this guide to assist utilities and other entities in filing applications for (1) authorizations to export electricity and (2) Presidential Permits. The guide is not intended to be all inclusive; however, it will provide an applicant with the type of information required in the application, define lead times, and direct an applicant to the proper source documents for preparing a complete application. The booklet is organized into two sections. The first part outlines the procedures for preparing an application for authorization to export electricity. The second part outlines the procedures for applying for a Presidential Permit to construct, connect, operate, or maintain electric transmission facilities at international boundaries.

  15. ACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 2010 ACEEE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    is the best suited variable speed wind generator for high power wind farms apart from complex control tragedy

  16. Axions and 'light shining through a wall': A detailed theoretical analysis

    SciTech Connect (OSTI)

    Adler, Stephen L. [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)], E-mail: adler@ias.edu; Gamboa, J. [Departamento de Fisica, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: jgamboa@usach.cl; Mendez, F. [Departamento de Fisica, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: fmendez@usach.cl; Lopez-Sarrion, J. [Department of Physics, The City College of the CUNY, NY 10031 (United States)], E-mail: justinux75@gmail.com

    2008-11-15T23:59:59.000Z

    We give a detailed study of axion-photon and photon-axion conversion amplitudes, which enter the analysis of 'light shining through a wall' experiments. Several different calculational methods are employed and compared, and in all cases we retain a nonzero axion mass. To leading order, we find that when the photon frequency {omega} is very close to the axion mass m, there is a threshold cusp which significantly enhances the photon to axion conversion amplitude, by a factor {omega}/{radical}({omega}{sup 2}-m{sup 2}) relative to the corresponding axion to photon conversion process. When m=0, the enhancement factor reduces to unity and the results of previous calculations are recovered. Our calculations include an exact wave matching analysis, which shows how unitarity is maintained near threshold at {omega}=m, and a discussion of the case when the magnetic field extends into the 'wall' region.

  17. Axion electrodynamics and dark matter fingerprints in the terrestrial magnetic and electric fields

    E-Print Network [OSTI]

    A. B. Balakin; L. V. Grunskaya

    2012-09-27T23:59:59.000Z

    We consider mathematical aspects of the axion electrodynamics in application to the problem of evolution of geomagnetic and terrestrial electric fields, which are coupled by relic axions born in the early Universe and (hypothetically) forming now the cold dark matter. We find axionic analogs of the Debye potentials, well-known in the standard Faraday - Maxwell electrodynamics, and discuss exact solutions to the equations of the axion electrodynamics describing the state of axionically coupled electric and magnetic fields in a spherical resonator Earth-Ionosphere. We focus on the properties of the specific electric and magnetic oscillations, which appeared as a result of the axion-photon coupling in the dark matter environment. We indicate such electric and magnetic field configurations as longitudinal electro-magnetic clusters.

  18. Mississippi State Axion Search: A Light Shining though a Wall ALP Search

    E-Print Network [OSTI]

    Mohanmurthy, Prajwal; Formaggio, Joseph; Fowler, Nicholas; Gaerlan, Mikhail; Jiang, Yipeng; Madsen, John; Oblath, Noah; Powers, Adam; Ray, Amy; Riehle, Robertson

    2015-01-01T23:59:59.000Z

    The elegant solutions to the strong CP problem predict the existence of a particle called axion. Thus, the search for axion like particles (ALP) has been an ongoing endeavor. The possibility that these axion like particles couple to photons in presence of magnetic field gives rise to a technique of detecting these particles known as light shining through a wall (LSW). Mississippi State Axion Search (MASS) is an experiment employing the LSW technique in search for axion like particles. The apparatus consists of two radio frequency (RF) cavities, both under the influence of strong magnetic field and separated by a lead wall. While one of the cavities houses a strong RF generator, the other cavity houses the detector systems. The MASS apparatus looks for excesses in RF photons that tunnel through the wall as a signature of candidate axion-like particles. The concept behind the experiment as well as the projected sensitivities are presented here.

  19. Mississippi State Axion Search: A Light Shining though a Wall ALP Search

    E-Print Network [OSTI]

    Prajwal Mohanmurthy; Dipangkar Dutta; Joseph Formaggio; Nicholas Fowler; Mikhail Gaerlan; Yipeng Jiang; John Madsen; Noah Oblath; Adam Powers; Amy Ray; Robertson Riehle

    2015-03-08T23:59:59.000Z

    The elegant solutions to the strong CP problem predict the existence of a particle called axion. Thus, the search for axion like particles (ALP) has been an ongoing endeavor. The possibility that these axion like particles couple to photons in presence of magnetic field gives rise to a technique of detecting these particles known as light shining through a wall (LSW). Mississippi State Axion Search (MASS) is an experiment employing the LSW technique in search for axion like particles. The apparatus consists of two radio frequency (RF) cavities, both under the influence of strong magnetic field and separated by a lead wall. While one of the cavities houses a strong RF generator, the other cavity houses the detector systems. The MASS apparatus looks for excesses in RF photons that tunnel through the wall as a signature of candidate axion-like particles. The concept behind the experiment as well as the projected sensitivities are presented here.

  20. ACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 2010 ACEEE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the transmission of control signals via large distances in a multimachine power system. Fast response and pure to a multimachine power system requires to sending these signals through large distances of transmission channels ACEEE DOI: 01.ijepe.01.01.02 Centralized Optimal Control for a Multimachine Power System Stability

  1. ACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 2010 ACEEE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ACEEE DOI: 01.ijepe.01.01.03 Security Constrained UCP with Operational and Power Flow Constraints S An algorithm to solve security constrained unit commitment problem (UCP) with both operational and power flow model repeated optimal power flow for the satisfactory unit combinations for every line removal under

  2. Andersen Efficient Audio Power Amplification -Challenges International Conference, Copenhagen, Denmark, 2005 September 24 1

    E-Print Network [OSTI]

    . ANDERSEN Oersted-DTU, Technical University of Denmark, Lyngby, Denmark ma@oersted.dtu.dk For more than in various forms are the state-of-the-art. The technical steps that lead to this evolution are described. As the dominating audio power amplifier principle was the class-B/AB higher output power meant higher power losses

  3. The Axion Dark-Matter eXperiment: Results and plans

    E-Print Network [OSTI]

    Tanner, David B.

    The Axion Dark-Matter eXperiment: Results and plans S.J. Asztalos,1 R. Bradley,2 G. Carosi,1 J.3204/DESY-PROC-2011-04/rybka gray The axion affects issues of the origin of CP symmetry in the strongV­ 10 meV, with the low end of this range (1­10 µeV) especially significant for dark-matter axions

  4. Axion Searches in the Past, at Present, and in the Near Future

    E-Print Network [OSTI]

    R. Battesti; B. Beltran; H. Davoudiasl; M. Kuster; P. Pugnat; R. Rabadan; A. Ringwald; N. Spooner; K. Zioutas

    2007-05-04T23:59:59.000Z

    Theoretical axion models state that axions are very weakly interacting particles. In order to experimentally detect them, the use of colorful and inspired techniques becomes mandatory. There is a wide variety of experimental approaches that were developed during the last 30 years, most of them make use of the Primakoff effect, by which axions convert into photons in the presence of an electromagnetic field. We review the experimental techniques used to search for axions and will give an outlook on experiments planned for the near future.

  5. Axion Bose-Einstein Condensation: a model beyond Cold Dark Matter

    SciTech Connect (OSTI)

    Yang, Q. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2010-08-30T23:59:59.000Z

    Cold dark matter axions form a Bose-Einstein condensate if the axions thermalize. Recently, it was found [1] that they do thermalize when the photon temperature reaches T{approx}100 eV(f/10{sup 12} GeV){sup 1/2} and that they continue to do so thereafter. We discuss the differences between axion BEC and CDM in the linear regime and the non-linear regime of evolution of density perturbations. We find that axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multi-poles.

  6. Extending the reach of axion-photon regeneration experiments towards larger masses with phase shift plates

    E-Print Network [OSTI]

    Joerg Jaeckel; Andreas Ringwald

    2007-06-05T23:59:59.000Z

    We present a scheme to extend the sensitivity of axion-photon regeneration experiments towards larger masses with the help of properly chosen and placed phase shift plates.

  7. Search for solar hadronic axions produced by a bremsstrahlung-like process

    E-Print Network [OSTI]

    D. Kekez; A. Ljubicic; Z. Krecak; M. Krcmar

    2008-12-22T23:59:59.000Z

    We have searched for hadronic axions which may be produced in the Sun by a bremsstrahlung-like process, and observed in the HPGe detector by an axioelectric effect. A conservative upper limit on the hadronic axion mass m_a < 334 eV at 95% C.L. is obtained. Our experimental approach is based on the axion-electron coupling and it does not include the axion-nucleon coupling, which suffers from the large uncertainties related to the estimation of the flavor-singlet axial-vector matrix element.

  8. Modeling the performance of the piston ring-pack with consideration of non-axisymmetric characteristics of the power cylinder system in internal combustion engines

    E-Print Network [OSTI]

    Liu, Liang, 1971-

    2005-01-01T23:59:59.000Z

    The performance of the piston ring-pack is directly associated with the friction, oil consumption, wear, and blow-by in internal combustion engines. Because of non-axisymmetric characteristics of the power cylinder system, ...

  9. Pathos and policy: the power of emotions in shaping perceptions of international relations 

    E-Print Network [OSTI]

    Skorick, J Mark

    2006-10-30T23:59:59.000Z

    of emotions is introduced and integrated into the existing research on foreign policy decision making. Hypotheses pertaining to the influence of negative emotions on information processing and choice in international relations are derived from the model...

  10. International Conference on the Physics of Reactors "Nuclear Power: A Sustainable Resource" Casino-Kursaal Conference Center, Interlaken, Switzerland, September 14-19, 2008

    E-Print Network [OSTI]

    Boyer, Edmond

    International Conference on the Physics of Reactors "Nuclear Power: A Sustainable Resource" Casino International Forum for the new nuclear energy systems, we have developed a new concept of molten salt reactor Products which poison the core can be extracted without stopping reactor operation; nuclear waste

  11. Search for Sub-eV Mass Solar Axions by the CERN Axion Solar Telescope with {sup 3}He Buffer Gas

    SciTech Connect (OSTI)

    Arik, M.; Cetin, S. A.; Ezer, C.; Yildiz, S. C. [Dogus University, Istanbul (Turkey); Aune, S.; Ferrer-Ribas, E.; Giomataris, I.; Papaevangelou, T. [IRFU, Centre d'Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Barth, K.; Borghi, S.; Davenport, M.; Elias, N.; Haug, F.; Laurent, J. M.; Niinikoski, T.; Silva, P. S.; Stewart, L. [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A.; Gninenko, S. [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Braeuninger, H. [Max-Planck-Institut fuer Extraterrestrische Physik, Garching (Germany)

    2011-12-23T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using {sup 3}He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with {sup 4}He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV < or approx. m{sub a} < or approx. 0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g{sub a}{gamma} < or approx. 2.3x10{sup -10} GeV{sup -1} at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m{sub a} < or approx. 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  12. ACEEE International Journal on Electrical and Power Engineering, Vol. 1, No. 1, Jan 2010 2010 ACEEE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with accrued benefits on account of their cleanliness, modularity, high efficiency & reliability. Among the different green power technologies e.g. wind power, photovoltaic, micro turbine, & fuel cells, the fuel cell efficiency (40-60%), reliability and higher potential capability [1],[2]. The Distributed Generation in fact

  13. Experimental determination of radiated internal wave power without pressure field Frank M. Lee,1

    E-Print Network [OSTI]

    Morrison, Philip J.,

    = S d2 x pv · ^n , (1) where J = pv is the baroclinic energy flux, p is the perturbed pressure field, v to determine, using only velocity field data, the time-averaged energy flux J and total radiated power P) that can be used to compute the energy flux and power from any two-dimensional velocity field data. PACS

  14. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison (Presentation)

    SciTech Connect (OSTI)

    Zhang, J.; Hodge, B.; Miettinen, J.; Holttinen, H.; Gomez-Lozaro, E.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Lovholm, A.; Berge, E.; Dobschinski, J.

    2013-10-01T23:59:59.000Z

    This presentation summarizes the work to investigate the uncertainty in wind forecasting at different times of year and compare wind forecast errors in different power systems using large-scale wind power prediction data from six countries: the United States, Finland, Spain, Denmark, Norway, and Germany.

  15. Search for low Energy solar Axions with CAST

    E-Print Network [OSTI]

    Arik, E; Autiero, D; Barth, K; Belov, A; Beltrán, B; Borghi, S; Boydag, F S; Bräuninger, H; Cantatore, G; Carmona, J M; Cebrián, S; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Dogan, O B; Eleftheriadis, C; Elias, N; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Galán, J; Gazis, E; Geralis, T; Giomataris, Ioanis; Gninenko, S; Gómez, H; Hasinoff, M; Heinsius, F H; Hikmet, I; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovicic, K; Kang, D; Karageorgopoulou, T; Karuza, M; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzón, 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; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, Pasquale Dario; Solanki, S K; Soufli, R; Stewart, L; Tsagri, M; Van Bibber, K; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2008-01-01T23:59:59.000Z

    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.

  16. Search for low Energy solar Axions with CAST

    E-Print Network [OSTI]

    Giovanni Cantatore; for the CAST Collaboration; :; E. Arik; S. Aune; D. Autiero; K. Barth; A. Belov; B. Beltrán; S. Borghi; F. S. Boydag; H. Bräuninger; G. Cantatore; J. M. Carmona; S. Cebrián; S. A. Cetin; J. I. Collar; T. Dafni; M. Davenport; L. Di Lella; O. B. Dogan; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; H. Fischer; J. Franz; J. Galán; E. Gazis; T. Geralis; I. Giomataris; S. Gninenko; H. Gómez; M. Hasinoff; F. H. Heinsius; I. Hikmet; D. H. H. Hoffmann; I. G. Irastorza; J. Jacoby; K. Jakov?i?; D. Kang; T. Karageorgopoulou; M. Karuza; K. Königsmann; R. Kotthaus; M. Kr?mar; K. Kousouris; M. Kuster; B. Laki?; C. Lasseur; A. Liolios; A. Ljubi?i?; V. Lozza; G. Lutz; G. Luzón; D. Miller; A. Morales; {deceased}; J. Morales; T. Niinikoski; A. Nordt; A. Ortiz; T. Papaevangelou; M. Pivovaroff; A. Placci; G. Raiteri; G. Raffelt; H. Riege; A. Rodríguez; J. Ruz; I. Savvidis; Y. Semertzidis; P. Serpico; S. K. Solanki; R. Soufli; L. Stewart; M. Tsagri; K. van Bibber; J. Villar; J. Vogel; L. Walckiers; K. Zioutas

    2008-09-29T23:59:59.000Z

    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.

  17. Photon-Axion-Like Particle Coupling Constant and Cosmological Observations

    E-Print Network [OSTI]

    M. Yu. Piotrovich; Yu. N. Gnedin; T. M. Natsvlishvili

    2008-05-23T23:59:59.000Z

    We estimated the photon-pseudoscalar particle mixing constant from the effect of cosmological alignment and cosmological rotation of polarization plane of distant QSOs. This effect is explained in terms of birefringent phenomenon due to photon-pseudoscalar (axion-like) particle mixing in a cosmic magnetic field. On the contrary, one can estimate the strength of the cosmic magnetic field using the constraints on the photon-axion-like particle coupling constant from the CAST experiment and from SNe Ia dimming effect. In a result, the lower limit on the intergalactic ($z\\approx 1\\div 2$) magnetic field appears at the level of about $4\\times 10^{-10}\\div 10^{-11}$ G.

  18. Non-Gaussianity in Axion N-flation Models

    SciTech Connect (OSTI)

    Kim, Soo A. [Department of Astronomy and Space Science, Kyung Hee University, Yong-in 446-701 (Korea, Republic of); Liddle, Andrew R.; Seery, David [Astronomy Centre, University of Sussex, Brighton BN1 9QH (United Kingdom)

    2010-10-29T23:59:59.000Z

    We study perturbations in the multifield axion N-flation model, taking account of the full cosine potential. We find significant differences from previous analyses which made a quadratic approximation to the potential. The tensor-to-scalar ratio and the scalar spectral index move to lower values, which nevertheless provide an acceptable fit to observation. Most significantly, we find that the bispectrum non-Gaussianity parameter f{sub NL} may be large, typically of order 10 for moderate values of the axion decay constant, increasing to of order 100 for decay constants slightly smaller than the Planck scale. Such a non-Gaussian fraction is detectable. We argue that this property is generic in multifield models of hilltop inflation.

  19. Holographic transports and stability in anisotropic linear axion model

    E-Print Network [OSTI]

    Xian-Hui Ge; Yi Ling; Chao Niu; Sang-Jin Sin

    2015-01-15T23:59:59.000Z

    We study thermoelectric conductivities and shear viscosities in a holographically anisotropic model. Momentum relaxation is realized through perturbing the linear axion field. AC conductivity exhibits a conherent/incoherent metal transition. The longitudinal shear viscosity for prolate anisotropy violates the bound conjectured by Kovtun-Son-Starinets. We also find that thermodynamic and dynamical instabilities are not always equivalent, which provides a counter example of the Gubser-Mitra conjecture.

  20. New polarimetric constraints on axion-like particles

    SciTech Connect (OSTI)

    Payez, A.; Cudell, J.R.; Hutsemékers, D., E-mail: A.Payez@ulg.ac.be, E-mail: JR.Cudell@ulg.ac.be, E-mail: D.Hutsemekers@ulg.ac.be [AGO Dept., U. of Liège, allée du 6 août 17, Liège (Belgium)

    2012-07-01T23:59:59.000Z

    We show that the parameter space of axion-like particles can be severely constrained using high-precision measurements of quasar polarisations. Robust limits are derived from the measured bounds on optical circular polarisation and from the distribution of linear polarisations of quasars. As an outlook, this technique can be improved by the observation of objects located behind clusters of galaxies, using upcoming space-borne X-ray polarimeters.

  1. Brane-antibrane backreaction in axion monodromy inflation

    SciTech Connect (OSTI)

    Conlon, Joseph P., E-mail: j.conlon1@physics.ox.ac.uk [Rudolf Peierls Center for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

    2012-01-01T23:59:59.000Z

    We calculate the interaction potential between D5 and D-bar 5 branes wrapping distant but homologous 2-cycles. The interaction potential is logarithmic in the separation radius and does not decouple at infinity. We show that logarithmic backreaction is generic for 5-branes wrapping distant but homologous 2-cycles, and we argue that this destabilises models of axion monodromy inflation involving NS5 brane-antibrane pairs in separate warped throats towards an uncontrolled region.

  2. Entropy of charged dilaton-axion black hole

    E-Print Network [OSTI]

    Tanwi Ghosh; Soumitra SenGupta

    2008-06-06T23:59:59.000Z

    Using brick wall method the entropy of charged dilaton-axion black hole is determined for both asymptotically flat and non-flat cases. The entropy turns out to be proportional to the horizon area of the black hole confirming the Beckenstien, Hawking area-entropy formula for black holes. The leading order logarithmic corrections to the entropy are also derived for such black holes.

  3. Measurement of the magnetically-induced QED birefringence of the vacuum and an improved search for laboratory axions: Technical report. Project definition study of the use of assets and facilities of the Superconducting Super Collider Laboratory

    SciTech Connect (OSTI)

    Lee, S.A.; Fairbank, W.M. Jr.; Toki, W.H. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Physics; Hall, J.L. [Univ. of Colorado, Boulder, CO (United States). Joint Inst. for Lab. Astrophysics]|[National Inst. of Standards and Technology, Boulder, CO (United States); Kraushaar, P.F. Jr.; Jaffery, T.S. [Superconducting Super Collider Lab., Waxahachie, TX (United States)

    1994-10-31T23:59:59.000Z

    The Colorado State Collaboration has studied the feasibility of a high sensitivity QED birefringence/axion search measurement. The objective of this work is to measure, for the first time, the birefringence induced in the vacuum on a light beam travelling in a powerful magnetic field. The same experimental setup also allows a highly sensitive search for axion or axion-like particles. The experiment would combined custom-designed optical heterodyne interferometry with a string of six SSC prototype superconducting dipole magnets at the N-15 site of the SSC Laboratory. With these powerful laser tools, sensitivity advances of 10{sup 7} to 10{sup 9} over previous optical experiments will be possible. The proposed experiment will be able to measure the QED light-by-light scattering effect with a 0.5% accuracy. The increased sensitivity for the axion-two photon interaction will result in a bound on this process rivaling the results based on astrophysical arguments. In the technical report the authors address the scientific significance of these experiments and examine the limiting technical parameters which control their feasibility. The proposed optical/electronic scheme is presented in the context of a background of the known and projected systematic problems which will confront any serious attempt to make such measurements.

  4. Dilaton and axion as compensators coupled to N=1 supergravity

    SciTech Connect (OSTI)

    Nishino, Hitoshi; Rajpoot, Subhash [Department of Physics and Astronomy, California State University, 1250 Bellflower Boulevard, Long Beach, California 90840 (United States)

    2008-12-15T23:59:59.000Z

    We present a locally N=1 supersymmetric model of the dilaton {phi} and the two-form tensor (axion) B{sub {mu}}{sub {nu}} as compensators without propagation. This is a generalization of our previous model with global N=1 supersymmetry to local N=1 supersymmetry. The dilaton {phi} and the axion B{sub {mu}}{sub {nu}} are, respectively, absorbed into the vector A{sub {mu}} and the three-form tensor C{sub {mu}}{sub {nu}}{sub {rho}}, where the latter is dual to the ordinary auxiliary field D in the usual vector multiplet. With local N=1 supersymmetry, we have three multiplets: the multiplet of supergravity (e{sub {mu}}{sup m},{psi}{sub {mu}}), linear multiplet (B{sub {mu}}{sub {nu}},{chi},{phi}), and the vector multiplet (A{sub {mu}},{lambda},C{sub {mu}}{sub {nu}}{sub {rho}}). We find that the field strengths of B and C need the following particular Chern-Simons terms for consistency with local supersymmetry: G{identical_to}3dB-6BD{phi}+3mBA+mC and H=4dC-6BF+4GA+8CD{phi}-4mCA. The newly established supergravity couplings provide the supporting evidence of the consistency of our basic system of the dilaton and axion as compensators.

  5. New constraints for heavy axion-like particles from supernovae

    SciTech Connect (OSTI)

    Giannotti, M.; Nita, R. [Physical Sciences, Barry University, Miami Shores, FL 33161 (United States); Duffy, L.D., E-mail: mgiannotti@mail.barry.edu, E-mail: ldd@lanl.gov, E-mail: Rafaela.Nita@mymail.barry.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2011-01-01T23:59:59.000Z

    We derive new constraints on the coupling of heavy pseudoscalar (axion-like) particles to photons, based on the gamma ray flux expected from the decay of these particles into photons. After being produced in the supernova core, these heavy axion-like particles would escape and a fraction of them would decay into photons before reaching the Earth. We have calculated the expected flux on Earth of these photons from the supernovae SN 1987A and Cassiopeia A and compared our results to data from the Fermi Large Area Telescope. This analysis provides strong constraints on the parameter space for axion-like particles. For a particle mass of 100 MeV, we find that the Peccei-Quinn constant, f{sub a}, must be greater than about 10{sup 15} GeV. Alternatively, for f{sub a} = 10{sup 12} GeV, we exclude the mass region between approximately 100 eV and 1 GeV.

  6. Gauge-preheating and the end of axion inflation

    E-Print Network [OSTI]

    Adshead, Peter; Scully, Timothy R; Sfakianakis, Evangelos I

    2015-01-01T23:59:59.000Z

    We study the onset of the reheating epoch at the end of axion-driven inflation where the axion is coupled to an Abelian, $U(1)$, gauge field via a Chern-Simons interaction term. We focus primarily on $m^2\\phi^2$ inflation and explore the possibility that preheating can occur for a range of coupling values consistent with recent observations and bounds on the overproduction of primordial black holes. We find that for a wide range of parameters preheating is efficient. In certain cases the inflaton is seen to transfer all its energy to the gauge fields within a few oscillations. We find that the gauge fields on sub-horizon scales end in an unpolarized state, due to the existence of strong rescattering between the inflaton and gauge modes. We also present a preliminary study of an axion monodromy model coupled to $U(1)$ gauge fields, seeing a similarly efficient preheating behavior as well as indications that the coupling strength has an effect on the creation of oscillons.

  7. Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

    SciTech Connect (OSTI)

    Not Available

    1992-10-01T23:59:59.000Z

    This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.

  8. New PVLAS model independent limit for the axion coupling to $??$ for axion masses above 1meV

    E-Print Network [OSTI]

    F. Della Valle; A. Ejlli; U. Gastaldi; G. Messineo; E. Milotti; R. Pengo; L. Piemontese; G. Ruoso; G. Zavattini

    2014-10-15T23:59:59.000Z

    During 2014 the PVLAS experiment has started data taking with a new apparatus installed at the INFN Section of Ferrara, Italy. The main target of the experiment is the observation of magnetic birefringence of vacuum. According to QED, the ellipticity generated by the magnetic birefringence of vacuum in the experimental apparatus is expected to be $\\psi^{\\rm(QED)} \\approx 5\\times10^{-11}$. No ellipticity signal is present so far with a noise floor $\\psi^{\\rm(noise)} \\approx 2.5\\times10^{-9}$ after 210 hours of data taking. The resulting ellipticity limit provides the best model independent upper limit on the coupling of axions to $\\gamma\\gamma$ for axion masses above $10^{-3}$eV.

  9. AIP/123-QED Experimental determination of radiated internal wave power without pressure field

    E-Print Network [OSTI]

    Texas at Austin. University of

    S is given by, P = S d2 x J · ^n = S d2 x pv · ^n , (1) where J = pv is the baroclinic energy flux, p, using only velocity field data, the time-averaged energy flux J and total radiated power P for two the energy flux and power from any two-dimensional velocity field data. PACS numbers: Valid PACS appear here

  10. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison: Preprint

    SciTech Connect (OSTI)

    Zhang, J.; Hodge, B. M.; Gomez-Lazaro, E.; Lovholm, A. L.; Berge, E.; Miettinen, J.; Holttinen, H.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Dobschinski, J.

    2013-10-01T23:59:59.000Z

    One of the critical challenges of wind power integration is the variable and uncertain nature of the resource. This paper investigates the variability and uncertainty in wind forecasting for multiple power systems in six countries. An extensive comparison of wind forecasting is performed among the six power systems by analyzing the following scenarios: (i) wind forecast errors throughout a year; (ii) forecast errors at a specific time of day throughout a year; (iii) forecast errors at peak and off-peak hours of a day; (iv) forecast errors in different seasons; (v) extreme forecasts with large overforecast or underforecast errors; and (vi) forecast errors when wind power generation is at different percentages of the total wind capacity. The kernel density estimation method is adopted to characterize the distribution of forecast errors. The results show that the level of uncertainty and the forecast error distribution vary among different power systems and scenarios. In addition, for most power systems, (i) there is a tendency to underforecast in winter; and (ii) the forecasts in winter generally have more uncertainty than the forecasts in summer.

  11. Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

    E-Print Network [OSTI]

    García, Juan Antonio

    2015-01-01T23:59:59.000Z

    Axions are well motivated particles proposed in an extension of the SM as a solution to the strong CP problem. Also, there is the category of Axion-Like Particles (ALPs) which appear in extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data of the three Micromegas detectors during the 2011 data taking campaign at CAST is presented in this thesis, obtaining a limit on the coupling constant of g$_{a \\gamma}$ < 3.90 $\\times$ 10$^{-10}$ GeV$^{-1}$ at a 95$\\%$ of confidence level, for axion masses from 1 to 1.17 eV. CAST Micromegas detectors exploit different strategies developed for the reduction of the background level. Moreov...

  12. Determination of effective axion masses in the helium-3 buffer of CAST

    SciTech Connect (OSTI)

    Ruz, J

    2011-11-18T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c{sup 2}. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c{sup 2}. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  13. Solving Cosmological Problems of Supersymmetric Axion Models in an Inflationary Universe

    E-Print Network [OSTI]

    Masahiro Kawasaki; Kazunori Nakayama

    2008-04-28T23:59:59.000Z

    We revisit inflationary cosmology of axion models in the light of recent developments on the inflaton decay in supergravity. We find that all the cosmological difficulties, including gravitino, axino overproduction and axionic isocurvature fluctuation, can be avoided if the saxion field has large initial amplitude during inflation and decays before big-bang nucleosynthesis.

  14. Asymptotic singular behaviour of inhomogeneous cosmologies in Einstein-Maxwell-dilaton-axion theory

    E-Print Network [OSTI]

    Luis A. Lopez; Nora Breton

    2006-08-29T23:59:59.000Z

    We present the study of exact inhomogeneous cosmological solutions to a four-dimensional low energy limit of string theory containing non-minimal interacting electromagnetic, dilaton and axion fields. We analyze Einstein-Rosen solutions of Einstein-Maxwell-dilaton-axion equations and show, by explicitly taken the asymptotic limits, that they have asymptotically velocity-term dominated (AVTD) singularities.

  15. Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

    E-Print Network [OSTI]

    Garcia Pascual, Juan Antonio

    Axions are well motivated particles proposed in an extension of the Standard Model (SM) as a solution to the CP problem in strong interactions. On the other hand, there is the category of axion-like particles (ALPs) which appear in diverse extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are hypothetical neutral particles that interact weakly with matter, being candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. The magnet is mounted on a movable platform that allows tracking the Sun $\\sim$1.5 hours during sunset and during sunrise. The axion signal would be an excess of X-rays in the detectors located at the magnet bore ends and thus low background detectors are mandatory. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data o...

  16. The asymmetry and the diurnal variation in axionic dark matter searches

    E-Print Network [OSTI]

    Y. Semertzidis; J. D. Vergados

    2014-12-22T23:59:59.000Z

    In the present work we propose to study the modulation signal in Axion Dark Matter searches. This can be seen in directional experiments employing cylindrical resonant cavities, which exploit the axion photon-conversion in the presence of strong magnetic fields

  17. INTERNATIONAL AGREEMENTS

    Office of Environmental Management (EM)

    generators, reactor pressure vessel and internals, cables, piping, pumps, valves) - optimization of nuclear power plant generation capacity (digital I&C upgrades, advanced...

  18. Generation and search of axion-like light particle using intense crystalline field

    E-Print Network [OSTI]

    Wei Liao

    2011-07-19T23:59:59.000Z

    Intense electric field $\\sim 10^{10}-10^{11}$ V/cm in crystal has been known for a long time and has wide applications. We study the conversion of axion-like light particle and photon in the intense electric field in crystal. We find that the conversion of axion-like particle and photon happens for energy larger than keV range. We propose search of axion-like light particle using the intense crystalline field. We discuss the solar axion search experiment and a variety of shining-through-wall experiment using crystalline field. Due to the intense crystalline field which corresponds to magnetic field $\\sim 10^4-10^5$ Tesla these experiments are very interesting. In particular these experiments can probe the mass range of axion-like particle from eV to keV.

  19. Constraints on axion-nucleon coupling constants from measuring the Casimir force between corrugated surfaces

    E-Print Network [OSTI]

    V. B. Bezerra; G. L. Klimchitskaya; V. M. Mostepanenko; C. Romero

    2014-08-31T23:59:59.000Z

    We obtain stronger laboratory constraints on the coupling constants of axion-like particles to nucleons from measurements of the normal and lateral Casimir forces between sinusoidally corrugated surfaces of a sphere and a plate. For this purpose, the normal and lateral additional force arising in the experimental configurations due to two-axion exchange between protons and neutrons are calculated. Our constraints following from measurements of the normal and lateral Casimir forces are stronger than the laboratory constraints reported so far for masses of axion-like particles larger than 11eV and 8eV, respectively. A comparison between various laboratory constraints on the coupling constants of axion-like particles to nucleons obtained from the magnetometer measurements, Eotvos- and Cavendish-type experiments, and from the Casimir effect is performed over the wide range of masses of axion-like particles from 10^{-10}eV to 20eV.

  20. The topological susceptibility from grand canonical simulations in the interacting instanton liquid model: chiral phase transition and axion mass

    E-Print Network [OSTI]

    Olivier Wantz; E. P. S. Shellard

    2010-01-14T23:59:59.000Z

    This is the last in a series of papers on the topological susceptibility in the interacting instanton liquid model (IILM). We will derive improved finite temperature interactions to study the thermodynamic limit of grand canonical Monte Carlo simulations in the quenched and unquenched case with light, physical quark masses. In particular, we will be interested in chiral symmetry breaking. The paper culminates by giving, for the first time, a well-motivated temperature-dependent axion mass. Especially, this work finally provides a computation of the axion mass in the low temperature regime, $m^2_a f^2_a = 1.46 10^{-3}\\Lambda^4 \\frac{1+0.50 T/\\Lambda}{1+(3.53 T/\\Lambda)^{7.48}}$. It connects smoothly to the high temperature dilute gas approximation; the latter is improved by including quark threshold effects. To compare with earlier studies, we also provide the usual power-law $m^2_a = \\frac{\\alpha_a \\Lambda^4}{f_a^2 (T/\\Lambda)^n}$, where $\\Lambda=400\\units{MeV}$, $n=6.68$ and $\\alpha=1.68 10^{-7}$.

  1. Gamma-ray boxes from axion-mediated dark matter

    SciTech Connect (OSTI)

    Ibarra, Alejandro; Gehler, Sergio López; Pato, Miguel [Physik-Department T30d, Technische Universität München, James-Franck-Strasse, 85748 Garching (Germany); Lee, Hyun Min; Park, Wan-Il, E-mail: ibarra@tum.de, E-mail: hyun.min.lee@cern.ch, E-mail: sergio.lopez@ph.tum.de, E-mail: wipark@kias.re.kr, E-mail: miguel.pato@tum.de [School of Physics, KIAS, Seoul 130-722 (Korea, Republic of)

    2013-05-01T23:59:59.000Z

    We compute the gamma-ray output of axion-mediated dark matter and derive the corresponding constraints set by recent data. In such scenarios the dark matter candidate is a Dirac fermion that pair-annihilates into axions and/or scalars. Provided that the axion decays (at least partly) into photons, these models naturally give rise to a box-shaped gamma-ray spectrum that may present two distinct phenomenological behaviours: a narrow box, resembling a line at half the dark matter mass, or a wide box, spanning an extensive energy range up to the dark matter mass. Remarkably, we find that in both cases a sizable gamma-ray flux is predicted for a thermal relic without fine-tuning the model parameters nor invoking boost factors. This large output is in line with recent Fermi-LAT observations towards the galactic centre region and is on the verge of being excluded. We then make use of the Fermi-LAT and H.E.S.S. data to derive robust, model-independent upper limits on the dark matter annihilation cross section for the narrow and wide box scenarios. H.E.S.S. constraints, in particular, turn out to match the ones from Fermi-LAT at hundreds of GeV and extend to multi-TeV masses. Future ?erenkov telescopes will likely probe gamma-ray boxes from thermal dark matter relics in the whole multi-TeV range, a region hardly accessible to direct detection, collider searches and other indirect detection strategies.

  2. Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

    E-Print Network [OSTI]

    Rosu, Madalin Mihai; Zioutas, Konstantin

    2015-06-09T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced due to the Primakoff effect in the hot and dense core of from the coupling of a real and a virtual photon. The solar models predict a peak Axion luminosity at an energy of 3 keV originating mostly from the inner 20% of the solar radius. Thus an intensity peak at an energy of 3 keV is also expected in the case of the X-ray radiation resulting from Axion conversion. CAST uses a high precision movement system for tracking the Sun twice a day with a LHC dipole twin aperture prototype magnet, 9.26 meters long and with a field of...

  3. Bounds on QCD axion mass and primordial magnetic field from CMB $?$-distortion

    E-Print Network [OSTI]

    Damian Ejlli

    2014-11-19T23:59:59.000Z

    The oscillation of the CMB photons into axions can cause CMB spectral distortion in the presence of large scale magnetic field. With the COBE limit on the $\\mu$ parameter and a homogeneous magnetic field with strength $B\\lesssim 3.2$ nG at the horizon scale, stronger lower limit on the axion mass in comparison with the limit of the ADMX experiment is found to be, $4.8\\times 10^{-5}$ eV $\\lesssim m_a$ for the KSVZ axion model. On the other hand, using the experimental limit on the axion mass $3.5\\times 10^{-6}$ eV $\\lesssim m_a$ from the ADMX experiment together with the COBE bound on $\\mu$, is found $B\\lesssim 53$ nG for the KSVZ axion model and $B\\lesssim 141$ nG for DFSZ axion model, for a homogeneous magnetic field with coherence length at the present epoch $\\lambda_B\\sim 1.3$ Mpc. Limits on $B$ and $m_a$ for PIXIE/PRISM expected sensitivity on $\\mu$ are derived. If CMB $\\mu$ distortion would be detected by the future space missions PIXIE/PRISM and assuming that the strength of the large scale magnetic field is close to its canonical value, $B\\sim 1-3$ nG, axions in the mass range $2\\, \\mu$eV - $3\\, \\mu$eV would be potential candidates of CMB $\\mu$-distortion.

  4. Detailed design of a resonantly enhanced axion-photon regeneration experiment

    SciTech Connect (OSTI)

    Mueller, Guido; Sikivie, Pierre; Tanner, D. B.; Bibber, Karl van [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Naval Postgraduate School, Monterey, California 93943 (United States)

    2009-10-01T23:59:59.000Z

    A resonantly enhanced photon-regeneration experiment to search for the axion or axionlike particles is described. This experiment is a shining light through walls study, where photons traveling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon-regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/{pi}){sup 2}, where F is the finesse of each cavity. This gain could feasibly be as high as 10{sup 10}, corresponding to an improvement in the sensitivity to the axion-photon coupling, g{sub a{gamma}}{sub {gamma}}, of order (F/{pi}){sup 1/2}{approx}300. This improvement would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.

  5. Axion Couplings and Effective Cut-Offs in Superstring Compactifications

    E-Print Network [OSTI]

    Mary K. Gaillard; T. R. Taylor

    1992-02-18T23:59:59.000Z

    We use the linear supermultiplet formalism of supergravity to study axion couplings and chiral anomalies in the context of field-theoretical Lagrangians describing orbifold compactifications beyond the classical approximation. By matching amplitudes computed in the effective low energy theory with the results of string loop calculations we determine the appropriate counterterm in this effective theory that assures modular invariance to all loop order. We use supersymmetry consistency constraints to identify the correct ultra-violet cut-offs for the effective low energy theory. Our results have a simple interpretation in terms of two-loop unification of gauge coupling constants at the string scale.

  6. Spectroscopy of the Einstein-Maxwell-Dilaton-Axion black hole

    E-Print Network [OSTI]

    Deyou Chen; Haitang Yang

    2012-10-03T23:59:59.000Z

    The entropy spectrum of a spherically symmetric black hole was derived via the Bohr-Sommerfeld quantization rule in Majhi and Vagenas's work. Extending this work to charged and rotating black holes, we quantize the horizon area and the entropy of an Einstein-Maxwell-Dilaton-Axion (EMDA) black hole via the Bohr-Sommerfeld quantization rule and the adiabatic invariance. The result shows the area spectrum and the entropy spectrum are respectively equally spaced and independent on the parameters of the black hole.

  7. Improved Constraints on an Axion-Mediated Force

    SciTech Connect (OSTI)

    Hoedl, S. A.; Fleischer, F.; Adelberger, E. G.; Heckel, B. R. [Center for Experimental Nuclear Physics and Astrophysics, Box 354290, University of Washington, Seattle, Washington 98195-4290 (United States)

    2011-01-28T23:59:59.000Z

    Low mass pseudoscalars, such as the axion, can mediate macroscopic parity and time-reversal symmetry-violating forces. We searched for such a force between polarized electrons and unpolarized atoms using a novel, magnetically unshielded torsion pendulum. We improved the laboratory bounds on this force by more than 10 orders of magnitude for pseudoscalars heavier than 1 meV and have constrained this force over a broad range of astrophysically interesting masses (10 {mu}eV to 10 meV).

  8. Integrating Variable Renewable Energy in Electric Power Markers: Best Practices from International Experience

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other NewsSpin andInterim DataCooling -INTEGRATING

  9. Microsoft PowerPoint - Pittsburgh International Airport to Morgantown Site Directions.ppt [Compatibility Mode]

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand RetrievalsFinalModule8.pptStates AOnline0,PROJECTS

  10. Results and perspectives of the solar axion search with the CAST experiment

    E-Print Network [OSTI]

    E. Ferrer-Ribas; M. Arik; S. Aune; K. Barth; A. Belov; S. Borghi; H. Bräuninger; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; T. Dafni; M. Davenport; C. Eleftheriadis; N. Elias; C. Ezer; G. Fanourakis; P. Friedrich; J. Galán; J. A. García; A. Gardikiotis; J. G. Garza; E. N. Gazis; T. Geralis; I. Giomataris; S. Gninenko; H. Gómez; E. Gruber; T. Guthörl; R. Hartmann; F. Haug; M. D. Hasinoff; D. H. H. Hoffmann; F. J. Iguaz; I. G. Irastorza; J. Jacoby; K. Jakov\\vci?; M. Karuza; K. Königsmann; R. Kotthaus; M. Kr?mar; M. Kuster; B. Laki?; J. M. Laurent; A. Liolios; A. Ljubi?i?; V. Lozza; G. Lutz; G. Luzón; J. Morales; T. Niinikoski; A. Nordt; T. Papaevangelou; M. J. Pivovaroff; G. Raffelt; T. Rashba; H. Riege; A. Rodríguez; M. Rosu; J. Ruz; I. Savvidis; P. S. Silva; S. K. Solanki; L. Stewart; A. Tomás; M. Tsagri; K. van Bibber; T. Vafeiadis; J. Villar; J. K. Vogel; S. C. Yildiz; K. Zioutas

    2012-10-30T23:59:59.000Z

    The status of the solar axion search with the CERN Axion Solar Telescope (CAST) will be presented. Recent results obtained by the use of $^3$He as a buffer gas has allowed us to extend our sensitivity to higher axion masses than our previous measurements with $^4$He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV$ \\le m_{a} \\le $ 0.64 eV. From the absence of an excess of x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g$_{a\\gamma} \\le 2.3\\times 10^{-10}$ GeV$^{-1}$ at 95% C.L., the exact value depending on the pressure setting. CAST published results represent the best experimental limit on the photon couplings to axions and other similar exotic particles dubbed WISPs (Weakly Interacting Slim Particles) in the considered mass range and for the first time the limit enters the region favored by QCD axion models. Preliminary sensitivities for axion masses up to 1.16 eV will also be shown reaching mean upper limits on the axion-photon coupling of g$_{a\\gamma} \\le 3.5\\times 10^{-10}$ GeV$^{-1}$ at 95% C.L. Expected sensibilities for the extension of the CAST program up to 2014 will be presented. Moreover long term options for a new helioscope experiment will be evoked.

  11. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience

    SciTech Connect (OSTI)

    Cochran, J.; Bird, L.; Heeter, J.; Arent, D. A.

    2012-04-01T23:59:59.000Z

    Many countries -- reflecting very different geographies, markets, and power systems -- are successfully managing high levels of variable renewable energy on the electric grid, including that from wind and solar energy. This study documents the diverse approaches to effective integration of variable renewable energy among six countries -- Australia (South Australia), Denmark, Germany, Ireland, Spain, and the United States (Western region-Colorado and Texas)-- and summarizes policy best practices that energy ministers and other stakeholders can pursue to ensure that electricity markets and power systems can effectively coevolve with increasing penetrations of variable renewable energy. Each country has crafted its own combination of policies, market designs, and system operations to achieve the system reliability and flexibility needed to successfully integrate renewables. Notwithstanding this diversity, the approaches taken by the countries studied all coalesce around five strategic areas: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations. The ability to maintain a broad ecosystem perspective, to organize and make available the wealth of experiences, and to ensure a clear path from analysis to enactment should be the primary focus going forward.

  12. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience, Summary for Policymakers

    SciTech Connect (OSTI)

    Cochran, J.; Bird, L.; Heeter, J.; Arent, D. A.

    2012-04-01T23:59:59.000Z

    Many countries -- reflecting very different geographies, markets, and power systems -- are successfully managing high levels of variable renewable energy on the electric grid, including that from wind and solar energy. This document summarizes policy best practices that energy ministers and other stakeholders can pursue to ensure that electricity markets and power systems can effectively coevolve with increasing penetrations of variable renewable energy. There is no one-size-fits-all approach; each country studied has crafted its own combination of policies, market designs, and system operations to achieve the system reliability and flexibility needed to successfully integrate renewables. Notwithstanding this diversity, the approaches taken by the countries studied all coalesce around five strategic areas: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations. This study also emphatically underscores the value of countries sharing their experiences. The more diverse and robust the experience base from which a country can draw, the more likely that it will be able to implement an appropriate, optimized, and system-wide approach.

  13. Finding the Axion: The Search for the Dark Matter of the Universe

    SciTech Connect (OSTI)

    Carosi, G. [LLNL, L-270, 7000 East Ave, Livermore, CA, 94550 (United States)

    2007-04-23T23:59:59.000Z

    The nature of dark matter has been a mystery for over 70 years. One plausible candidate is the axion, an extremely light and weakly interacting particle, which results from the Peccei-Quinn solution to the strong CP problem. In this proceedings I will briefly review the evidence for dark matter as well as the motivation for the existence of the axion as a prime dark matter candidate. I will then discuss the experimental methods to search for axion dark matter focusing on a sensitive cavity experiment (ADMX) being run at Lawrence Livermore National Laboratory.

  14. Finding the Axion: The Search for the Dark Matter of the Universe

    SciTech Connect (OSTI)

    Carosi, G

    2006-11-03T23:59:59.000Z

    The nature of dark matter has been a mystery for over 70 years. One plausible candidate is the axion, an extremely light and weakly interacting particle, which results from the Peccei-Quinn solution to the strong CP problem. In this proceedings I will briefly review the evidence for dark matter as well as the motivation for the existence of the axion as a prime dark matter candidate. I will then discuss the experimental methods to search for axion dark matter focusing on a sensitive cavity experiment (ADMX) being run at Lawrence Livermore National Laboratory.

  15. The Axion Dark-Matter eXperiment (ADMX): Recent Results

    SciTech Connect (OSTI)

    Rosenberg, Leslie J. [Department of Physics, University of Washington, Seattle WA 98195 (United States)

    2010-08-30T23:59:59.000Z

    The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in the strong interactions. It's properties in addition make it a good dark-matter candidate. Even though dark-matter axions would make up the overwhelming majority of mass in the universe, they are extraordinarily difficult to detect. We have developed a detector, ADMX, for dark-matter axions that is at heart an exquisitely sensitive detector of electromagnetic radiation. This talk will describe the progress we have made in this experimental search.

  16. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-10-01T23:59:59.000Z

    Many countries--reflecting very different geographies, markets, and power systems--are successfully managing high levels of variable renewable energy (RE) on the grid. Australia (South Australia), Denmark, Germany, Ireland, Spain, and the United States (Colorado and Texas), for example, have effectively integrated variable RE utilizing diverse approaches. Analysis of the results from these case studies reveals a wide range of mechanisms that can be used to accommodate high penetrations of variable RE (e.g., from new market designs to centralized planning). Nevertheless, the myriad approaches collectively suggest that governments can best enable variable RE grid integration by implementing best practices in five areas of intervention: lead public engagement, particularly for new transmission; coordinate and integrate planning; develop rules for market evolution that enable system flexibility; expand access to diverse resources and geographic footprint of operations; and improve system operations.

  17. The key word is "supplying." In a load center or panel board, the main circuit breaker supplies power to the internal

    E-Print Network [OSTI]

    Johnson, Eric E.

    power to the internal bus bars, as do any backfed circuit breakers supplying power from the PV inverters these numbers translate to a 3,840-watt (AC inverter output) PV system on a 100-amp panel and a 7,680-watt PV on the circuit breakers. Many common PV inverters are rated at 2,500 watts and 240 volts. The rated output

  18. INTERNATIONAL CONFERENCE ON COMMUNICATION, COMPUTER AND POWER (ICCCP'09) MUSCAT, FEBRUARY 15-18, 2009 SQU-2009 ISSN: 1813-419X -1 -

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    INTERNATIONAL CONFERENCE ON COMMUNICATION, COMPUTER AND POWER (ICCCP'09) MUSCAT, FEBRUARY 15 on a precise recall of passwords and/or personal identifier numbers (PINs). As the number of on-line services as users seek passwords that they can readily remember. This has a potential security risk that could

  19. CAST solar axion search with 3^He buffer gas: Closing the hot dark matter gap

    E-Print Network [OSTI]

    M. Arik; S. Aune; K. Barth; A. Belov; S. Borghi; H. Brauninger; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; E. Da Riva; T. Dafni; M. Davenport; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; P. Friedrich; J. Galan; J. A. Garcia; A. Gardikiotis; J. G. Garza; E. N. Gazis; T. Geralis; E. Georgiopoulou; I. Giomataris; S. Gninenko; H. Gomez; M. Gomez Marzoa; E. Gruber; T. Guthorl; R. Hartmann; S. Hauf; F. Haug; M. D. Hasinoff; D. H. H. Hoffmann; F. J. Iguaz; I. G. Irastorza; J. Jacoby; K. Jakovcic; M. Karuza; K. Konigsmann; R. Kotthaus; M. Krcmar; M. Kuster; B. Lakic; P. M. Lang; J. M. Laurent; A. Liolios; A. Ljubicic; V. Lozza; G. Luzon; S. Neff; T. Niinikoski; A. Nordt; T. Papaevangelou; M. J. Pivovaroff; G. Raffelt; H. Riege; A. Rodriguez; M. Rosu; J. Ruz; I. Savvidis; I. Shilon; P. S. Silva; S. K. Solanki; L. Stewart; A. Tomas; M. Tsagri; K. van Bibber; T. Vafeiadis; J. Villar; J. K. Vogel; S. C. Yildiz; K. Zioutas

    2014-09-15T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  20. More on critical collapse of axion-dilaton system in dimension four

    SciTech Connect (OSTI)

    Álvarez-Gaumé, Luis [Theory Group, Physics Department, CERN, CH-1211, Geneva 23 (Switzerland); Hatefi, Ehsan, E-mail: Luis.Alvarez-Gaume@cern.ch, E-mail: ehsan.hatefi@cern.ch [International Centre for Theoretical Physics, Strada Costiera 11, Trieste (Italy)

    2013-10-01T23:59:59.000Z

    We complete our previous study of critical gravitational collapse in the axion-dilaton system by analysing the hyperbolic and parabolic ansaetze. As could be expected, the corresponding Choptuik exponents in four-dimensions differ from the elliptic case.

  1. Constraining the axion portal with B{yields}Kl{sup +}l{sup -}

    SciTech Connect (OSTI)

    Freytsis, Marat; Thaler, Jesse [Berkeley Center for Theoretical Physics, Department of Physics, University of California, Berkeley, California 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Ligeti, Zoltan [Theoretical Physics Group, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

    2010-02-01T23:59:59.000Z

    We investigate the bounds on axionlike states from flavor-changing neutral current b{yields}s decays, assuming the axion couples to the standard model through mixing with the Higgs sector. Such GeV-scale axions have received renewed attention in connection with observed cosmic ray excesses. We find that existing B{yields}Kl{sup +}l{sup -} data impose stringent bounds on the axion decay constant in the multi-TeV range, relevant for constraining the 'axion portal' model of dark matter. Such bounds also constrain light Higgs scenarios in the next-to-minimal supersymmetric standard model. These bounds can be improved by dedicated searches in B-factory data and at LHCb.

  2. Effects of axion-photon mixing on gamma-ray spectra from magnetized astrophysical sources

    SciTech Connect (OSTI)

    Hochmuth, Kathrin A. [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Munich (Germany); Sigl, Guenter [APC - AstroParticules et Cosmologie, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France) and Institut d'Astrophysique de Paris, UMR 7095 CNRS-Universite Pierre and Marie Curie, 98 bis boulevard Arago, F-75014 Paris (France)

    2007-12-15T23:59:59.000Z

    Astrophysical {gamma}-ray sources come in a variety of sizes and magnetizations. We deduce general conditions under which {gamma}-ray spectra from such sources would be significantly affected by axion-photon mixing. We show that, depending on strength and coherence of the magnetic field, axion couplings down to {approx}(10{sup 13}GeV){sup -1} can give rise to significant axion-photon conversions in the environment of accreting massive black holes. Resonances can occur between the axion mass term and the plasma frequency term as well as between the plasma frequency term and the vacuum Cotton-Mouton shift. Both resonances and nonresonant transitions could induce detectable features or even strong suppressions in finite energy intervals of {gamma}-ray spectra from active galactic nuclei. Such effects can occur at keV to TeV energies for couplings that are currently allowed by all experimental constraints.

  3. Probing the eV-Mass Range for Solar Axions with CAST

    SciTech Connect (OSTI)

    Vogel, J K; Pivovaroff, M J; Soufli, R; van Bibber, K; CAST, C

    2010-11-11T23:59:59.000Z

    The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, {sup 4}He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing {sup 3}He phase the studied mass range is now being extended further. In this contribution the final results of CAST's {sup 4}He phase will be presented and the current status of the {sup 3}He run will be given. This includes latest results as well as prospects of future axion experiments.

  4. Density gradients and absorption effects in gas-filled magnetic axion helioscopes

    SciTech Connect (OSTI)

    Creswick, R. J.; Avignone, F. T. III [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina, 29208 (United States); Nussinov, S [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina, 29208 (United States); Department of Physics, Tel Aviv University, Tel Aviv, Israel 69978 (Israel)

    2008-07-01T23:59:59.000Z

    The effects of absorption in the gas, and of density variations on the sensitivity of gas-filled solar-axion helioscopes, are theoretically investigated. It is concluded that the 10-meter long CAST helioscope, the most sensitive experiment to date, is near the limit of sensitivity in axion mass. Increasing the length, gas density, or tilt angle all have negative influences and will not improve the sensitivity.

  5. SIGNATURES OF PHOTON-AXION CONVERSION IN THE THERMAL SPECTRA AND POLARIZATION OF NEUTRON STARS

    SciTech Connect (OSTI)

    Perna, Rosalba [JILA and Department of Astrophysical and Planetary Science, University of Colorado at Boulder, 440 UCB, Boulder, CO 80304 (United States); Ho, Wynn C. G. [School of Mathematics, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Verde, Licia; Jimenez, Raul [ICREA and ICC, University of Barcelona (IEEC-UB) (Spain); Van Adelsberg, Matthew [Center for Relativistic Astrophysics and School of Physics Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2012-04-01T23:59:59.000Z

    Conversion of photons into axions under the presence of a strong magnetic field can dim the radiation from magnetized astrophysical objects. Here we perform a detailed calculation aimed at quantifying the signatures of photon-axion conversion in the spectra, light curves, and polarization of neutron stars (NSs). We take into account the energy and angle dependence of the conversion probability and the surface thermal emission from NSs. The latter is computed from magnetized atmosphere models that include the effect of photon polarization mode conversion due to vacuum polarization. The resulting spectral models, inclusive of the general-relativistic effects of gravitational redshift and light deflection, allow us to make realistic predictions for the effects of photon to axion conversion on observed NS spectra, light curves, and polarization signals. We identify unique signatures of the conversion, such as an increase of the effective area of a hot spot as it rotates away from the observer line of sight. For a star emitting from the entire surface, the conversion produces apparent radii that are either larger or smaller (depending on axion mass and coupling strength) than the limits set by NS equations of state. For an emission region that is observed phase-on, photon-axion conversion results in an inversion of the plane of polarization with respect to the no-conversion case. While the quantitative details of the features that we identify depend on NS properties (magnetic field strength and temperature) and axion parameters, the spectral and polarization signatures induced by photon-axion conversion are distinctive enough to make NSs very interesting and promising probes of axion physics.

  6. Density Gradient and Absorption Effects in Gas-Filled Magnetic Axion Helioscopes

    E-Print Network [OSTI]

    R. J. Creswick; S. Nussinov; F. T. Avignone III

    2008-05-14T23:59:59.000Z

    The effects of absorption in the gas, and of density variations on the sensitivity of gas-filled solar-axion helioscopes are theoretically investigated. It is concluded that the 10-meter long CAST helioscope, the most sensitive experiment to date is near the limit of sensitivity in axion mass. Increasing the length, gas density, or tilt angle all have negative influences, and will not improve the sensitivity.

  7. Red-giant evolution, metallicity, and new bounds on hadronic axions

    SciTech Connect (OSTI)

    Haxton, W.C.; Lee, K.Y. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (US))

    1991-05-20T23:59:59.000Z

    We explore stellar cooling by nuclear axion emission, identifying those special isotopes that dominate this process for temperatures {similar to}10{sup 7}--10{sup 9} K. We argue that such nuclear energy-loss mechanisms are distinctive because the effects track metallicity. Three observables associated with evolution of stars along the red-giant and horizontal branches are shown to impose new and restrictive constraints on axions in the hadronic window.

  8. Axion mechanism of Sun luminosity and TSI variations: light shining through the solar radiation zone

    E-Print Network [OSTI]

    Rusov, V D; Sharf, I V; Eingorn, M V; Smolyar, V P; Vlasenko, D S; Zelentsova, T N; Linnik, E P; Beglaryan, M E

    2014-01-01T23:59:59.000Z

    It is shown that the hypothesis of the axion mechanism of Sun luminosity suggesting that the solar axion-like particles are born in the core of the Sun and may be efficiently converted back into $\\gamma$-quanta in the magnetic field of the solar overshoot tachocline is physically relevant. As a result, it is also shown that the intensity variations of the $\\gamma$-quanta of axion origin, induced by the magnetic field variations in the tachocline, directly cause the Sun luminosity and total solar irradiance (TSI) variations and eventually characterize the active and quiet states of the Sun. Within the framework of this mechanism estimations of the strength of the axion coupling to a photon ($g_{a \\gamma} = 7.2 \\cdot 10^{-11} GeV^{-1}$) and the axion-like particle mass ($m_a \\sim 10^{-5} eV$) have been obtained. It is also shown that the claimed axion parameters do not contradict any known experimental and theoretical model-independent limitations.

  9. Oscillating axion bubbles as alternative to supermassive black holes at galactic centers

    E-Print Network [OSTI]

    Anatoly A. Svidzinsky

    2007-10-30T23:59:59.000Z

    Recent observations of near-infrared and X-ray flares from Sagittarius A*, which is believed to be a supermassive black hole at the Galactic center, show that the source exhibits about 20-minute periodic variability. Here we provide arguments based on a quantitative analysis that supermassive objects at galactic centers may be bubbles of dark matter axions rather than black holes. An oscillating axion bubble can explain periodic variability of Sagittarius A* and yields the axion mass about 0.6 meV which fits in the open axion mass window. The bubble scenario with no other free parameters explains lack of supermassive "black holes" with mass Maxion bubble can not exceed 1.5\\times 10^9 M_{Sun}, in agreement with the upper limit on the supermassive "black hole" mass obtained from observations. Our finding, if confirmed, suggests that Einstein general relativity is invalid for strong gravity and the gravitational field for the bubble effectively becomes repulsive at large potential. Imaging a shadow of the "black hole" at the Galactic center with VLBI in the next decade can distinguish between the black hole and the oscillating axion bubble scenarios. In the case of axion bubble, a steady shadow will not be observed. Instead, the shadow will appear and disappear periodically with a period of about 20 min.

  10. Axions and saxions from the primordial supersymmetric plasma and extra radiation signatures

    SciTech Connect (OSTI)

    Graf, Peter; Steffen, Frank Daniel, E-mail: graf@mpp.mpg.de, E-mail: steffen@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, D–80805 Munich (Germany)

    2013-02-01T23:59:59.000Z

    We calculate the rate for thermal production of axions and saxions via scattering of quarks, gluons, squarks, and gluinos in the primordial supersymmetric plasma. Systematic field theoretical methods such as hard thermal loop resummation are applied to obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling. We calculate the thermally produced yield and the decoupling temperature for both axions and saxions. For the generic case in which saxion decays into axions are possible, the emitted axions can constitute extra radiation already prior to big bang nucleosynthesis and well thereafter. We update associated limits imposed by recent studies of the primordial helium-4 abundance and by precision cosmology of the cosmic microwave background and large scale structure. We show that the trend towards extra radiation seen in those studies can be explained by late decays of thermal saxions into axions and that upcoming Planck results will probe supersymmetric axion models with unprecedented sensitivity.

  11. Signatures of photon and axion-like particle mixing in the gamma-ray burst jet

    E-Print Network [OSTI]

    Olga Mena; Soebur Razzaque; F. Villaescusa-Navarro

    2011-02-07T23:59:59.000Z

    Photons couple to Axion-Like Particles (ALPs) or more generally to any pseudo Nambu-Goldstone boson in the presence of an external electromagnetic field. Mixing between photons and ALPs in the strong magnetic field of a Gamma-Ray Burst (GRB) jet during the prompt emission phase can leave observable imprints on the gamma-ray polarization and spectrum. Mixing in the intergalactic medium is not expected to modify these signatures for ALP mass > 10^(-14) eV and/or for gamma ray emission. We also show that when the magnetic field orientation in the propagation region is perpendicular to the field orientation in the production region, the observed synchrotron spectrum becomes steeper than the theoretical prediction and as detected in a sizable fraction of GRB sample. Detection of the correlated polarization and spectral signatures from these steep-spectrum GRBs by gamma-ray polarimeters can be a very powerful probe to discover ALPs. Measurement of gamma-ray polarization from GRBs in general, with high statistics, can also be useful to search for ALPs.

  12. Wilson Fermions and Axion Electrodynamics in Optical Lattices

    E-Print Network [OSTI]

    A. Bermudez; L. Mazza; M. Rizzi; N. Goldman; M. Lewenstein; M. A. Martin-Delgado

    2010-11-12T23:59:59.000Z

    The formulation of massless relativistic fermions in lattice gauge theories is hampered by the fundamental problem of species doubling, namely, the rise of spurious fermions modifying the underlying physics. A suitable tailoring of the fermion masses prevents such abundance of species, and leads to the so-called Wilson fermions. Here we show that ultracold atoms provide us with the first controllable realization of these paradigmatic fermions, thus generating a quantum simulator of fermionic lattice gauge theories. We describe a novel scheme that exploits laser-assisted tunneling in a cubic optical superlattice to design the Wilson fermion masses. The high versatility of this proposal allows us to explore a variety of interesting phases in three-dimensional topological insulators, and to test the remarkable predictions of axion electrodynamics.

  13. Axion Like Particles and the Inverse Seesaw Mechanism

    E-Print Network [OSTI]

    Carvajal, C D R; Nishi, C C; Sánchez-Vega, B L

    2015-01-01T23:59:59.000Z

    Light pseudoscalars known as axion like particles (ALPs) may be behind physical phenomena like the Universe transparency to ultra-energetic photons, the soft $\\gamma$-ray excess from the Coma cluster, and the 3.5 keV line. We explore the connection of these particles with the inverse seesaw (ISS) mechanism for neutrino mass generation. We propose a very restrictive setting where the scalar field hosting the ALP is also responsible for generating the ISS mass scales through its vacuum expectation value on gravity induced nonrenormalizable operators. A discrete gauge symmetry protects the theory from the appearance of overly strong gravitational effects and discrete anomaly cancellation imposes strong constraints on the order of the group. The anomalous U$(1)$ symmetry leading to the ALP is an extended lepton number and the protective discrete symmetry can be always chosen as a subgroup of a combination of the lepton number and the baryon number.

  14. Adiabatic Pumping of Chern-Simons Axion Coupling

    E-Print Network [OSTI]

    Maryam Taherinejad; David Vanderbilt

    2014-11-06T23:59:59.000Z

    We study the adiabatic pumping of the Chern-Simons axion (CSA) coupling along a parametric loop characterized by a non-zero second Chern number $C^{(2)}$ from the viewpoint of the hybrid Wannier representation, in which the Wannier charge centers (WCCs) are visualized as sheets defined over a projected 2D Brillouin zone. We derive a new formula for the CSA coupling, expressing it as an integral involving Berry curvatures and potentials defined on the WCC sheets. We show that a loop characterized by a non-zero $C^{(2)}$ requires a series of sheet-touching events at which $2\\pi$ quanta of Berry curvature are passed from sheet to sheet, in such a way that $e^2/h$ units of CSA coupling are pumped by a lattice vector by the end of the cycle. We illustrate these behaviors via explicit calculations on a model tight-binding Hamiltonian and discuss their implications.

  15. Axionic superconductivity in three dimensional doped narrow gap semiconductors

    E-Print Network [OSTI]

    Pallab Goswami; Bitan Roy

    2014-08-07T23:59:59.000Z

    We consider the competition between the conventional s-wave and the triplet Balian-Werthamer or the B-phase pairings in the doped three dimensional narrow gap semiconductors, such as $\\mathrm{Cu}_x\\mathrm{Bi}_2\\mathrm{Se}_3$ and $\\mathrm{Sn}_{1-x}\\mathrm{In}_x\\mathrm{Te}$. When the coupling constants of the two contending channels are comparable, we find a simultaneously time-reversal and parity violating $p + is$ state at low temperatures, which provides an example of dynamic axionic state of matter. In contradistinction to the time-reversal invariant, topological B-phase, the $p + is$ state possesses gapped Majorana fermions as the surface Andreev bound states, which give rise to an anomalous surface thermal Hall effect. The anomalous gravitational and electrodynamic responses of the $p+is$ state can be described by the $\\theta$ vacuum structure, where $\\theta \

  16. Polarization mesurements of gamma ray bursts and axion like particles

    E-Print Network [OSTI]

    Andre Rubbia; Alexander Sakharov

    2008-09-03T23:59:59.000Z

    A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of axion like particles (ALPs). Based on evidences of polarized gamma ray emission detected in several gamma ray bursts we estimated the level of ALPs induced dichroism, which could take place in the magnetized fireball environment of a GRB. This allows to estimate the sensitivity of polarization measurements of GRBs to the ALP-photon coupling. This sensitivity $\\gag\\le 2.2\\cdot 10^{-11} {\\rm GeV^{-1}}$ calculated for the ALP mass $m_a=10^{-3}~{\\rm eV}$ and MeV energy spread of gamma ray emission is competitive with the sensitivity of CAST and becomes even stronger for lower ALPs masses.

  17. String theoretic QCD axions in the light of PLANCK and BICEP2

    E-Print Network [OSTI]

    Kiwoon Choi; Kwang Sik Jeong; Min-Seok Seo

    2014-07-21T23:59:59.000Z

    The QCD axion solving the strong CP problem may originate from antisymmetric tensor gauge fields in compactified string theory, with a decay constant around the GUT scale. Such possibility appears to be ruled out now by the detection of tensor modes by BICEP2 and the PLANCK constraints on isocurvature density perturbations. A more interesting and still viable possibility is that the string theoretic QCD axion is charged under an anomalous U(1)_A gauge symmetry. In such case, the axion decay constant can be much lower than the GUT scale if moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and U(1)_A-charged matter fields get a vacuum value far below the GUT scale due to a tachyonic SUSY breaking scalar mass. We examine the symmetry breaking pattern of such models during the inflationary epoch with the Hubble expansion rate 10^{14} GeV, and identify the range of the QCD axion decay constant, as well as the corresponding relic axion abundance, consistent with known cosmological constraints. In addition to the case that the PQ symmetry is restored during inflation, there are other viable scenarios, including that the PQ symmetry is broken during inflation at high scales around 10^{16}-10^{17} GeV due to a large Hubble-induced tachyonic scalar mass from the U(1)_A D-term, while the present axion scale is in the range 10^{9}-5\\times 10^{13} GeV, where the present value larger than 10^{12} GeV requires a fine-tuning of the axion misalignment angle. We also discuss the implications of our results for the size of SUSY breaking soft masses.

  18. An independent limit on the axion mass from the variable white dwarf star R548

    SciTech Connect (OSTI)

    Córsico, A.H.; Althaus, L.G. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, (1900) La Plata (Argentina); Romero, A.D.; Kepler, S.O. [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre 91501-970, RS (Brazil); Mukadam, A.S. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); García-Berro, E. [Departament de Física Aplicada, Universitat Politècnica de Catalunya, c/Esteve Terrades 5, 08860 Castelldefels (Spain); Isern, J. [Institut de Ciències de l'Espai (CSIC), Campus UAB, 08193 Bellaterra (Spain); Corti, M.A., E-mail: acorsico@fcaglp.unlp.edu.ar, E-mail: althaus@fcaglp.unlp.edu.ar, E-mail: aromero@fcaglp.unlp.edu.ar, E-mail: anjum@astro.washington.edu, E-mail: enrique.garcia-berro@upc.edu, E-mail: isern@ice.cat, E-mail: kepler@if.ufrgs.br, E-mail: mariela@fcaglp.fcaglp.unlp.edu.ar [Instituto Argentino de Radioastronomía (CCT-La Plata, CONICET), C.C. No. 5, 1894 Villa Elisa (Argentina)

    2012-12-01T23:59:59.000Z

    Pulsating white dwarfs with hydrogen-rich atmospheres, also known as DAV stars, can be used as astrophysical laboratories to constrain the properties of fundamental particles like axions. Comparing the measured cooling rates of these stars with the expected values from theoretical models allows us to search for sources of additional cooling due to the emission of weakly interacting particles. In this paper, we present an independent inference of the mass of the axion using the recent determination of the evolutionary cooling rate of R548, the DAV class prototype. We employ a state-of-the-art code which allows us to perform a detailed asteroseismological fit based on fully evolutionary sequences. Stellar cooling is the solely responsible of the rates of change of period with time (.?)) for the DAV class. Thus, the inclusion of axion emission in these sequences notably influences the evolutionary timescales, and also the expected pulsational properties of the DAV stars. This allows us to compare the theoretical .?) values to the corresponding empirical rate of change of period with time of R548 to discern the presence of axion cooling. We found that if the dominant period at 213.13 s in R548 is associated with a pulsation mode trapped in the hydrogen envelope, our models indicate the existence of additional cooling in this pulsating white dwarf, consistent with axions of mass m{sub a}cos {sup 2}? ? 17.1 meV at a 2? confidence level. This determination is in agreement with the value inferred from another well-studied DAV, G117-B15A. We now have two independent and consistent estimates of the mass of the axion obtained from DAVs, although additional studies of other pulsating white dwarfs are needed to confirm this value of the axion mass.

  19. 2005 International Conference on Wireless Networks, Communications and Mobile Computing Optimal Power Control for Multiple Access Channel

    E-Print Network [OSTI]

    Chen, Rong-Rong

    Power Control for Multiple Access Channel with Peak and Average Power Constraints Rong-Rong Chen}I@ece.utah.edu Abstract- In this paper, we study optimal power control for multiple access channel with peak and average and the receiver. We characterize the structures of the optimal power control policy and show that the optimal

  20. International Atomic Energy Agency specialists meeting on experience in ageing, maintenance, and modernization of instrumentation and control systems for improving nuclear power plant availability

    SciTech Connect (OSTI)

    Not Available

    1993-10-01T23:59:59.000Z

    This report presents the proceedings of the Specialist`s Meeting on Experience in Aging, Maintenance and Modernization of Instrumentation and Control Systems for Improving Nuclear Power Plant Availability that was held at the Ramada Inn in Rockville, Maryland on May 5--7, 1993. The Meeting was presented in cooperation with the Electric Power Research Institute, Oak Ridge National Laboratory and the International Atomic Energy Agency. There were approximately 65 participants from 13 countries at the Meeting. Individual reports have been cataloged separately.

  1. Role of local duality invariance in axion electrodynamics of topological insulators

    E-Print Network [OSTI]

    S. C. Tiwari

    2011-09-05T23:59:59.000Z

    Advances in material technology and confluence of ideas from particle physics, quantum field theory and condensed matter physics have led to the discovery of new states of matter as well as new physical phenomena: one of them termed as topological insulator has attracted a great deal of attention recently. Speculations on the possibility of observing the most elusive objects like axions and monopoles in topological insulators have led to studies that emphasize the role of symmetry and universality. In this paper we argue that electric-magnetic duality could be of deep significance in this context. We develop a duality invariant theory of topological insulators and show that under appropriate conditions this theory reduces to the axion electrodynamics for static case, topological quantization is related with the multi-valuedness of the duality gauge potential, and modifies Faraday's law for dynamical axion that would change the dispersion relation of axionic polariton. A new effect dual to the dynamical axion field effect is predicted and its physical consequences are discussed.

  2. Future Directions in the Microwave Cavity Search for Dark Matter Axions

    E-Print Network [OSTI]

    T. M. Shokair; J. Root; K. A. Van Bibber; B. Brubaker; Y. V. Gurevich; S. B. Cahn; S. K. Lamoreaux; M. A. Anil; K. W. Lehnert; B. K. Mitchell; A. Reed; G. Carosi

    2014-05-14T23:59:59.000Z

    The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonant conversion to photons in a microwave cavity permeated by a magnetic field. The current generation of the microwave cavity experiment has demonstrated sensitivity to plausible axion models, and upgrades in progress should achieve the sensitivity required for a definitive search, at least for low mass axions. However, a comprehensive strategy for scanning the entire mass range, from 1-1000 $\\mu$eV, will require significant technological advances to maintain the needed sensitivity at higher frequencies. Such advances could include sub-quantum-limited amplifiers based on squeezed vacuum states, bolometers, and/or superconducting microwave cavities. The Axion Dark Matter eXperiment at High Frequencies (ADMX-HF) represents both a pathfinder for first data in the 20-100 $\\mu$eV range ($\\sim$5-25 GHz), and an innovation test-bed for these concepts.

  3. Axion mass limit from observations of the neutron star in Cassiopeia A

    E-Print Network [OSTI]

    Lev B. Leinson

    2014-08-14T23:59:59.000Z

    Direct Chandra observations of a surface temperature of isolated neutron star in Cassiopeia A (Cas A NS) and its cooling scenario which has been recently simultaneously suggested by several scientific teams put stringent constraints on poorly known properties of the superfluid neutron star core. It was found also that the thermal energy losses from Cas A NS are approximately twice more intensive than it can be explained by the neutrino emission. We use these unique data and well-defined cooling scenario to estimate the strength of KSVZ axion interactions with neutrons. We speculate that enlarged energy losses occur owing to emission of axions from superfluid core of the neutron star. If the axion and neutrino losses are comparable we find $c_{n}^{2}m_{a}^{2}\\sim 5.7\\times 10^{-6}\\,\\text{eV}^2$, where $m_{a}$ is the axion mass, and $c_{n}$ is the effective Peccei-Quinn charge of the neutron. (Given the QCD uncertainties of the hadronic axion models, the dimensionless constant $c_{n}$ could range from $-0.05$ to $ 0.14$.)

  4. Constraining the photon-axion coupling constant with magnetic white dwarfs

    SciTech Connect (OSTI)

    Gill, Ramandeep; Heyl, Jeremy S. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)

    2011-10-15T23:59:59.000Z

    The light pseudoscalar particle, dubbed the axion, borne out of the Peccei-Quinn solution to the strong CP problem in QCD remains elusive. One avenue of inferring its existence is through its coupling to electromagnetic radiation. So far, laboratory experiments have dedicated all efforts to detect the axion in the mass range 10{sup -6}axion coupling strength g{sub a}{gamma}{gamma}<10{sup -10} GeV{sup -1}, where the limits are derived from astrophysical considerations. In this study, we present a novel way of constraining g{sub a}{gamma}{gamma} by looking at the level of linear polarization in the radiation emerging from magnetic white dwarfs. We find that photon-axion oscillations in white dwarf magnetospheres can enhance the degree of linear polarization. Observing that most magnetic white dwarfs show only 5% linear polarization, we derive upper limits on g{sub a}{gamma}{gamma} for different axion masses.

  5. A class of invisible axion models with FCNCs at tree level

    E-Print Network [OSTI]

    Alejandro Celis; Javier Fuentes-Martin; Hugo Serodio

    2015-01-06T23:59:59.000Z

    We build a class of invisible axion models with tree-level Flavor Changing Neutral Currents completely controlled by the fermion mixing matrices. The scalar sector of these models contains three-Higgs doublets and a complex scalar gauge singlet, with the same fermionic content than the Standard Model. A horizontal Peccei-Quinn symmetry provides a solution to the strong CP problem and predicts the existence of a very light and weakly coupled pseudo-Goldstone boson, the invisible axion or familon. A phenomenological analysis is performed taking into account familon searches in rare kaon and muon decays, astrophysical considerations and axion searches via axion-photon conversion. Drastic differences are found in the axion properties of different models due to the strong hierarchy of the CKM matrix, making some of the models considered much more constrained than others. We also obtain that a rich variety of these models avoid the domain wall problem. A possible mechanism to protect the solution to the strong CP problem against gravitational effects is also discussed.

  6. Photon production from the scattering of axions out of a solenoidal magnetic field

    SciTech Connect (OSTI)

    Guendelman, Eduardo I.; Shilon, Idan [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Cantatore, Giovanni [Università and INFN Trieste, via Valerio 2, 34127 Trieste (Italy); Zioutas, Konstantin, E-mail: guendel@bgu.ac.il, E-mail: silon@bgu.ac.il, E-mail: cantatore@trieste.infn.it, E-mail: Konstantin.Zioutas@cern.ch [Physics Department, University of Patras, Rio, 26504 Patras (Greece)

    2010-06-01T23:59:59.000Z

    We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D ?-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. Comparison between the 2D conversion probabilities for QCD inspired axions and those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect is made using an averaging prescription procedure of the 1D case. We also consider scattering at a resonance E{sub axion} ? m{sub axion}, which corresponds to the scattering from a ?-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem.

  7. Light supersymmetric axion in an anomalous Abelian extension of the standard model

    SciTech Connect (OSTI)

    Coriano, Claudio; Guzzi, Marco; Mariano, Antonio; Morelli, Simone [Dipartimento di Fisica, Universita del Salento Via Arnesano 73100 Lecce (Italy) and INFN Sezione di Lecce, Via Arnesano 73100 Lecce (Italy)

    2009-08-01T23:59:59.000Z

    We present a supersymmetric extension of the standard model (USSM-A) with an anomalous U(1) and Stueckelberg axions for anomaly cancellation, generalizing similar nonsupersymmetric constructions. The model, built by a bottom-up approach, is expected to capture the low-energy supersymmetric description of axionic symmetries in theories with gauged anomalous Abelian interactions, previously explored in the nonsupersymmetric case for scenarios with intersecting branes. The choice of a USSM-like superpotential, with one extra singlet superfield and an extra Abelian symmetry, allows a physical axionlike particle in the spectrum. We describe some general features of this construction and, in particular, the modification of the dark-matter sector which involves both the axion and several neutralinos with an axino component. The axion is expected to be very light in the absence of phases in the superpotential but could acquire a mass which can also be in the few GeV range or larger. In particular, the gauging of the anomalous symmetry allows independent mass/coupling interaction to the gauge fields of this particle, a feature which is absent in traditional (invisible) axion models. We comment on the general implications of our study for the signature of moduli from string theory due to the presence of these anomalous symmetries.

  8. 7th International Workshop on Large-Scale Integration of Wind Power and on Transmission Networks for Offshore Wind Farms Models for HLI analysis of power systems with

    E-Print Network [OSTI]

    Bak-Jensen, Birgitte

    for Offshore Wind Farms 1 Models for HLI analysis of power systems with offshore wind farms and distributed power plants, distributed generation and offshore wind farms. Particular attention is paid to the latter]-[4], but there is a lack of models of offshore wind farms, which introduce new issues for their representation, due to some

  9. Understanding Failures in International Safety-Critical Infrastructures: A Comparison of European and North American Power Failures

    E-Print Network [OSTI]

    Johnson, Chris

    of Glasgow, Scotland, UK. Keywords: Critical Infrastructures, Blackouts, Power Distribution, V2 Analysis. Abstract The increasing integration of safety-critical infrastructures introduces vulnerabilities-critical systems creates vulnerabilities across the power distribution, water supply and transportation industries

  10. International Journal of Power Electronics and Drive System (IJPEDS) Vol. 3, No. 1, March 2013, pp. 17~29

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    on the instantaneous power theory (p-q theory) to improve the wind generator performance through compensating

  11. 13th IEEE International Symposium on Consumer Electronics, 2009 Low-Power Multiplierless DCT for Image/Video

    E-Print Network [OSTI]

    Ziavras, Sotirios G.

    -- A multiplierless discrete cosine transform (DCT) architecture is proposed to improve the power efficiency of image/video coders. Power reduction is achieved by minimizing both the number of arithmetic operations and their bit; power dissipation; constant matrix multiplication (CMM) I. INTRODUCTION The discrete cosine transform

  12. Hawaii International Conference on System Science, January 2003, Hawaii, 2003 IEEE Blackout Mitigation Assessment in Power Transmission Systems

    E-Print Network [OSTI]

    @engr.wisc.edu Abstract Electric power transmission systems are a key infrastructure and blackouts of these systems have Electrical Reliability Council blackout data suggests the existence of blackout size distributions with power by the dynamics. 1. Introduction Electric power transmission systems are an important element of the national

  13. Proposal for a Search for Cosmic Axions Using an Optical Cavity

    SciTech Connect (OSTI)

    Melissinos, A. C. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)

    2009-05-22T23:59:59.000Z

    A high finesse optical cavity can be used to search for cosmic axions in the mass range 10{sup -6}axion density the usual figure of {rho}{sub a}=500 Mev/cm{sup 3}, the KSVZ axion line g{sub a{gamma}}{sub {gamma}}/m{sub a}=0.4 GeV{sup -2}, can be reached over the full mass range in a 1 yr search.

  14. Skewon-Axion Medium and Soft-and-Hard/DB Boundary Condition

    E-Print Network [OSTI]

    Ismo V. Lindell; Ari Sihvola

    2012-01-20T23:59:59.000Z

    The class of skewon-axion media can be defined in a simple and natural manner applying four-dimensional differential-form representation of electromagnetic fields and media. It has been recently shown that an interface of a uniaxial skewon-axion medium acts as a DB boundary requiring vanishing normal components of the D and B vectors. In the present paper a more general skewon-axion medium is considered. It is shown that a planar interface of such a medium acts as a boundary generalizing both soft-and-hard (SH) and DB boundary conditions to SHDB conditions. Reflection of a plane wave from a planar SHDB boundary is studied. It is shown that for the two eigenpolarizations the boundary can be replaced by equivalent PEC or PMC boundaries. The theory is tested with a numerical example.

  15. Negative spectral index of f{sub NL} in the axion-type curvaton model

    SciTech Connect (OSTI)

    Huang, Qing-Guo, E-mail: huangqg@itp.ac.cn [Kavli Institute for Theoretical Physics China (KITPC), Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-11-01T23:59:59.000Z

    We derive the spectral index of f{sub NL} and its running from isocurvature single field and investigate the curvaton models with a negative spectral index of f{sub NL} in detail. In particular, a numerical study of the axion-type curvaton model is illustrated, and we find that the spectral index of f{sub NL} is negative and its absolute value is maximized around ?{sub *} = ?f/2 for the potential V(?) = m{sup 2}f{sup 2}(1?cos (?/f)). The spectral index of f{sub NL} can be O(?0.1) for the axion-type curvaton model. A convincing detection of a positive n{sub f{sub N{sub L}}} will rule out the axion-type curvaton model. In addition, we also give a general discussion about the detectable parameter space for the curvaton model with a polynomial potential.

  16. Theoretical Estimate of the Sensitivity of the CUORE Detector to Solar Axions

    E-Print Network [OSTI]

    Li, Dawei; Avignone, F T; Wang, Yuanxu

    2015-01-01T23:59:59.000Z

    In this paper we calculate the potential sensitivity of the CUORE detector to axions produced in the Sun through the Primakoff process and detected by coherent Bragg conversion by the inverse Primakoff process. The conversion rate is calculated using density functional theory for the electron density and realistic expectations for the energy resolution and background of CUORE. Monte Carlo calculations for $5~$y$\\times741~$kg=$3705~$kg y of exposure are analyzed using time correlation of individual events with the theoretical time-dependent counting rate and lead to an expected limit on the axion-photon coupling $g_{a\\gamma\\gamma}<3.83\\times 10^{-10}~GeV^{-1}$ for axion masses less than several eV.

  17. Heat flow of the Earth and resonant capture of solar 57-Fe axions

    E-Print Network [OSTI]

    F. A. Danevich; A. V. Ivanov; V. V. Kobychev; V. I. Tretyak

    2009-05-07T23:59:59.000Z

    In a very conservative approach, supposing that total heat flow of the Earth is exclusively due to resonant capture inside the Earth of axions, emitted by 57-Fe nuclei on Sun, we obtain limit on mass of hadronic axion: m_aEarth, this estimation could be improved to the value: m_a<1.6 keV. Both the values are less restrictive than limits set in devoted experiments to search for 57-Fe axions (m_a<216-745 eV), but are much better than limits obtained in experiments with 83-Kr (m_a<5.5 keV) and 7-Li (m_a<13.9-32 keV).

  18. Magnetogenesis from axion and dilaton electromagnetism in torsioned spacetime

    E-Print Network [OSTI]

    L. C. G. Andrade

    2015-01-09T23:59:59.000Z

    Recently much controversy has been shed on BICEP 2 experiments for the concerning this validity or not and a possible set of new experiments to detect primordial inflation and gravitational waves. Since gravitational waves imply the existence of primordial magnetic fields in this context, C Bonvin, R Durrer and R Marteens [Phys Rev Lett (2014)] have tried to associate the presence of primordial magnetic fields to BICEP 2 by making use of CMB tensor modes. Here we show that by considering torsion dilatonic lagrangean one obtains cosmological magnetic fields of the order of $B\\sim{10^{-10}G}$ which may seed galactic dynamos. Actually this new result came out of a mistake of a recent paper published by myself in JCAP (2014). These results are more in accordance with Bamba results [JCAP (2014)] in the context of teleparallel theory of gravity with Einstein's distant parallelism and torsion. These results also support Einstein-Cartan sort of theories of gravity from well-known recent data. Another example which supports the use of modified gravities with torsion to investigate magnetogenesis is the alternative exampleof using axions with transmutation into torsion to obtain cosmic magnetic seed bound of $10^{-12}G$.This coincides with the lower bound obtained by Barrow et al [Phys Rev D (2012)] in the interval of $10^{-20}G$ to $10^{-12}G$ in Friedmann universes.

  19. Using government purchasing power to reduce equipment standby power

    E-Print Network [OSTI]

    Harris, Jeffrey; Meier, Alan; Bartholomew, Emily; Thomas, Alison; Glickman, Joan; Ware, Michelle

    2003-01-01T23:59:59.000Z

    or external power supply, other specifications, and purchasethe consumer to purchase extra power strips and extensionan internal standby power function, shall purchase Although

  20. Natural Theories of Ultra-Low Mass PNGB's: Axions and Quintessence

    E-Print Network [OSTI]

    Christopher T. Hill; Adam K. Leibovich

    2002-06-06T23:59:59.000Z

    We consider the Wilson Line PNGB which arises in a U(1)^N gauge theory, abstracted from a latticized, periodically compactified extra dimension U(1). Planck scale breaking of the PNGB's global symmetry is suppressed, providing natural candidates for the axion and quintessence. We construct an explicit model in which the axion may be viewed as the 5th component of the U(1)_Y gauge field in a 1+4 latticized periodically compactified extra dimension. We also construct a quintessence PNGB model where the ultra-low mass arises from Planck-scale suppressed physics itself.

  1. Quantization and 2{pi} periodicity of the axion action in topological insulators

    SciTech Connect (OSTI)

    Vazifeh, M. M.; Franz, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada)

    2010-12-15T23:59:59.000Z

    The Lagrangian describing the bulk electromagnetic response of a three-dimensional strong topological insulator contains a topological ''axion'' term of the form {theta}E{center_dot}B. It is often stated (without proof) that the corresponding action is quantized on periodic space time and therefore invariant under {theta}{yields}{theta}+2{pi}. Here we provide a simple, physically motivated proof of the axion action quantization on the periodic space time, assuming only that the vector potential is consistent with single valuedness of the electron wave functions in the underlying insulator.

  2. Pion mass effects on axion emission from neutron stars through NN bremsstrahlung processes

    E-Print Network [OSTI]

    S. Stoica; B. Pastrav; J. E. Horvath; M. P. Allen

    2009-11-30T23:59:59.000Z

    The rates of axion emission by nucleon-nucleon bremsstrahlung are calculated with the inclusion of the full momentum contribution from a nuclear one pion exchange (OPE) potential. The contributions of the neutron-neutron (nn), proton-proton (pp) and neutron-proton (np) processes in both the nondegenerate and degenerate limits are explicitly given. We find that the finite momentum corrections to the emissivities are quantitatively significant for the non-degenerate regime and temperature-dependent, and should affect the existing axion mass bounds. The trend of these nuclear effects is to diminish the emissivities.

  3. New generation low-energy probes for ultralight axion and scalar dark matter

    E-Print Network [OSTI]

    Stadnik, Yevgeny V

    2015-01-01T23:59:59.000Z

    We present a brief overview of a new generation of high-precision laboratory and astrophysical measurements to search for ultralight (sub-eV) axion, axion-like pseudoscalar and scalar dark matter, which form either a coherent condensate or topological defects (solitons). In these new detection methods, the sought effects are linear in the interaction constant between dark matter and ordinary matter, which is in stark contrast to traditional searches for dark matter, where the sought effects are quadratic or higher order in the underlying interaction constants (which are extremely small).

  4. Cardy-Verlinde formula for an axially symmetric dilaton-axion black hole

    E-Print Network [OSTI]

    Mubasher Jamil; M. Akbar; M. R. Setare

    2011-05-30T23:59:59.000Z

    It is shown that the Bekenstein-Hawking entropy of an axially symmetric dilaton-axion black hole can be expressed as a Cardy-Verlinde formula. By utilizing the first order quantum correction in the Bekenstein-Hawking entropy we find the modified expressions for the Casimir energy and pure extensive energy. The first order correction to the Cardy-Verlinde formula in the context of axially symmetric dilaton-axion black hole are obtained with the use of modified Casimir and pure extensive energies.

  5. New generation low-energy probes for ultralight axion and scalar dark matter

    E-Print Network [OSTI]

    Yevgeny V. Stadnik; Victor V. Flambaum

    2015-06-28T23:59:59.000Z

    We present a brief overview of a new generation of high-precision laboratory and astrophysical measurements to search for ultralight (sub-eV) axion, axion-like pseudoscalar and scalar dark matter, which form either a coherent condensate or topological defects (solitons). In these new detection methods, the sought effects are linear in the interaction constant between dark matter and ordinary matter, which is in stark contrast to traditional searches for dark matter, where the sought effects are quadratic or higher order in the underlying interaction constants (which are extremely small).

  6. Evolution of string-wall networks and axionic domain wall problem

    SciTech Connect (OSTI)

    Hiramatsu, Takashi [Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Kawasaki, Masahiro; Saikawa, Ken'ichi, E-mail: hiramatz@yukawa.kyoto-u.ac.jp, E-mail: kawasaki@icrr.u-tokyo.ac.jp, E-mail: saikawa@icrr.u-tokyo.ac.jp [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa City, Chiba 277-8582 (Japan)

    2011-08-01T23:59:59.000Z

    We study the cosmological evolution of domain walls bounded by strings which arise naturally in axion models. If we introduce a bias in the potential, walls become metastable and finally disappear. We perform two dimensional lattice simulations of domain wall networks and estimate the decay rate of domain walls. By using the numerical results, we give a constraint for the bias parameter and the Peccei-Quinn scale. We also discuss the possibility to probe axion models by direct detection of gravitational waves produced by domain walls.

  7. Theory for the Direct Detection of Solar Axions by Coherent Primakoff Conversion in Germanium Detectors

    E-Print Network [OSTI]

    R. J. Creswick; F. T. Avignone III; J. I. Collar; H. A. Farach; A. O. Gattone; S. Nussinov; K. Zioutas

    1997-08-01T23:59:59.000Z

    It is assumed that axions exist and are created in the Sun by Primakoff conversion of photons in the Coulomb fields of nuclei. Detection rates are calculated in germanium detectors due to the coherent conversion of axions to photons in the lattice when the incident angle fulfills the Bragg condition for a given crystalline plane. The rates are correlated with the relative positions of the Sun and detector, yielding a characteristic recognizable sub-diurnal temporal pattern. A major experiment is proposed based on a large detector array.

  8. Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion

    E-Print Network [OSTI]

    Guido D'Amico; Nemanja Kaloper

    2015-01-07T23:59:59.000Z

    Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.

  9. Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion

    E-Print Network [OSTI]

    D'Amico, Guido

    2015-01-01T23:59:59.000Z

    Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.

  10. Search for Resonant Absorption of Solar Axions Emitted in M1 Transition in $^{57}$Fe Nuclei

    E-Print Network [OSTI]

    A. V. Derbin; A. I. Egorov; I. A. Mitropol'sky; V. N. Muratova; D. A. Semenov; E. V. Unzhakov

    2009-06-01T23:59:59.000Z

    A search for resonant absorbtion of 14.4 keV solar axions by $^{57}$Fe target was performed. The Si(Li) detector placed inside the low-background setup was used to detect the $\\gamma$-quanta appearing in the deexcitation of 14.4 keV nuclear level: $A+\\rm{^{57}Fe} \\to \\rm{^{57}Fe^{*}} \\to \\rm{^{57}Fe} + \\gamma$. The new upper limit for the hadronic axion mass have been obtained: $m_{A} \\leq 151$ eV (90% C.L.) ($S$=0.5, $z$=0.56).

  11. Space Technology and Applications International Forum Proceedings, Albuquerque, New Mexico, January 2000 Miniaturized Radioisotope Solid State Power Sources

    E-Print Network [OSTI]

    thermoelectric generators (RTGs) have been successfully used for a number of deep space missions RTGs. However 2000 Miniaturized Radioisotope Solid State Power Sources J.-P. Fleurial, G.J. Snyder, J. Patel, J-pierre.fleurial@jpl.nasa.gov Abstract. Electrical power requirements for the next generation of deep space missions cover a wide range

  12. 2012 IEEE International Power Engineering and Optimization Conference (PEOC02012), Melaka, Malaysia: 6-7 June 2012 Design a Unified Power Quality Conditioner using

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    in market come with a enormous opportunity of using vehicle to grid (V2G) technology for power quality his working hour or the time he parked the car in home. The idea of using PHEV charging station demonstrated in V2G mode of operation. A smart park model with dynamic behavior of battery has been developed

  13. Improved constraints on the coupling constants of axion-like particles to nucleons from recent Casimir-less experiment

    E-Print Network [OSTI]

    G. L. Klimchitskaya; V. M. Mostepanenko

    2015-04-09T23:59:59.000Z

    We obtain improved constraints on the coupling constants of axion-like particles to nucleons from a recently performed Casimir-less experiment. For this purpose, the differential force between a Au-coated sphere and either Au or Si sectors of a rotating disc, arising due to two-axion exchange, is calculated. Over a wide region of axion masses from 1.7 meV to 0.9 eV the obtained constraints are stronger up to a factor of 60 than the previously known ones following from the Cavendish-type experiment and measurements of the effective Casimir pressure.

  14. Stronger constraints on the coupling constants of axion-like particles to nucleons from recent Casimir-less experiment

    E-Print Network [OSTI]

    Klimchitskaya, G L

    2015-01-01T23:59:59.000Z

    We obtain stronger constraints on the coupling constants of axion-like particles to nucleons from a recently performed Casimir-less experiment. For this purpose, the differential force between a Au-coated sphe\\-re and either Au or Si sectors of a rotating disc, arising due to two-axion exchange, is calculated. Over a wide region of axion masses from 1.7 meV to 0.9 eV the obtained constraints are stronger up to a factor of 60 than the previously known ones following from the Cavendish-type experiment and measurements of the effective Casimir pressure.

  15. Why is the Dark Axion Mass $10^{-22}$ eV?

    E-Print Network [OSTI]

    Tzihong Chiueh

    2014-09-25T23:59:59.000Z

    Scalar field dark matter likely is able to solve all small-scale cosmology problems facing the cold dark matter (CDM), and has become an emerging contender to challenge the CDM. It however requires a particle mass $\\sim 1 - 2 \\times10^{-22}$eV. We find such an extremely small particle mass can naturally arise from a non-QCD axion mechanism, under fairly general assumptions that a few species of self-interacting light particles of comparable masses and a massless gauge boson decouple from the bright sector since the photon temperature exceeds 200 GeV, and the axion is the dominant dark matter. These assumptions also set the axion decay constant scale to several $\\times 10^{16}$ GeV. Given the above axion mass range, we further pin down the dark-sector particles to consist of only one species of fermion and anti-fermion, likely right-handed neutrinos. With a mass around $92-128$ eV, the dark-sector particles may constitute a minority population of dark matter. If the gauge boson lives on SU(2), a dilute instanton gas can contribute about $2.5\\%$ of the total relativistic relics in the cosmic microwave background radiation.

  16. Dark energy, QCD axion, BICEP2, and trans-Planckian decay constant

    E-Print Network [OSTI]

    Jihn E. Kim

    2014-10-19T23:59:59.000Z

    Discrete symmetries allowed in string compactification are the mother of all global symmetries which are broken at some level. We discuss the resulting pseudo-Goldstone bosons, in particular the QCD axion and a temporary cosmological constant, and inflatons. We also comment on some implications of the recent BICEP2 data.

  17. Supersymmetry with radiatively-driven naturalness: implications for WIMP and axion searches

    E-Print Network [OSTI]

    Bae, Kyu Jung; Barger, Vernon; Savoy, Michael R; Serce, Hasan

    2015-01-01T23:59:59.000Z

    By insisting on naturalness in both the electroweak and QCD sectors of the MSSM, the portrait for dark matter production is seriously modified from the usual WIMP miracle picture. In SUSY models with radiatively-driven naturalness (radiative natural SUSY or RNS) which include a DFSZ-like solution to the strong CP and SUSY mu problems, dark matter is expected to be an admixture of both axions and higgsino-like WIMPs. The WIMP/axion abundance calculation requires simultaneous solution of a set of coupled Boltzmann equations which describe quasi-stable axinos and saxions. In most of parameter space, axions make up the dominant contribution of dark matter although regions of WIMP dominance also occur. We show the allowed range of PQ scale f_a and compare to the values expected to be probed by the ADMX axion detector in the near future. We also show WIMP detection rates which are suppressed from usual expectations because now WIMPs comprise only a fraction of the total dark matter. Nonetheless, ton-scale noble liq...

  18. Uniqueness Theorem for Stationary Axisymmetric Black Holes in Einstein-Maxwell-axion-dilaton Gravity

    E-Print Network [OSTI]

    Marek Rogatko

    2010-07-26T23:59:59.000Z

    We prove the uniqueness theorem for stationary axisymmetric black hole solution in Einstein-Maxwell-axion-dilaton gravity being the low-energy limit of the heterotic string theory. We consider both non-degenerate and extremal Kerr-Sen black hole solutions.

  19. Coupled Boltzmann calculation of mixed axion/neutralino cold dark matter production in the early universe

    SciTech Connect (OSTI)

    Baer, Howard; Sreethawong, Warintorn [Dept. of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Lessa, Andre, E-mail: baer@nhn.ou.edu, E-mail: lessa@fma.if.usp.br, E-mail: wstan@nhn.ou.edu [Instituto de Física, Universidade de São Paulo, São Paulo (Brazil)

    2012-01-01T23:59:59.000Z

    We calculate the relic abundance of mixed axion/neutralino cold dark matter which arises in R-parity conserving supersymmetric (SUSY) models wherein the strong CP problem is solved by the Peccei-Quinn (PQ) mechanism with a concommitant axion/saxion/axino supermultiplet. By numerically solving the coupled Boltzmann equations, we include the combined effects of 1. thermal axino production with cascade decays to a neutralino LSP, 2. thermal saxion production and production via coherent oscillations along with cascade decays and entropy injection, 3. thermal neutralino production and re-annihilation after both axino and saxion decays, 4. gravitino production and decay and 5. axion production both thermally and via oscillations. For SUSY models with too high a standard neutralino thermal abundance, we find the combined effect of SUSY PQ particles is not enough to lower the neutralino abundance down to its measured value, while at the same time respecting bounds on late-decaying neutral particles from BBN. However, models with a standard neutralino underabundance can now be allowed with either neutralino or axion domination of dark matter, and furthermore, these models can allow the PQ breaking scale f{sub a} to be pushed up into the 10{sup 14}?10{sup 15} GeV range, which is where it is typically expected to be in string theory models.

  20. Subtleties of the fermion measure in the presence of axion fields

    E-Print Network [OSTI]

    P. Mitra

    2015-05-01T23:59:59.000Z

    It is known from path integral studies of the chiral anomaly that the fermion measure has to depend on gauge fields interacting with the fermion. It is pointed out here that in the presence of an axion field interacting with the fermion, it too is involved in the measure, with unexpected consequences for the utility of the field.

  1. Thin-shell wormholes from charged black holes in generalized dilaton-axion gravity

    E-Print Network [OSTI]

    A. A. Usmani; F. Rahaman; Saibal Ray; Sk. A. Rakib; Z. Hasan; Peter K. F. Kuhfittig

    2010-06-05T23:59:59.000Z

    This paper discusses a new type of thin-shell wormhole constructed by applying the cut-and-paste technique to two copies of a charged black hole in generalized dilaton-axion gravity, which was inspired by low-energy string theory. After analyzing various aspects of this thin-shell wormhole, we discuss its stability to linearized spherically symmetric perturbations.

  2. Uniqueness theorem for stationary axisymmetric black holes in Einstein-Maxwell-axion-dilaton gravity

    SciTech Connect (OSTI)

    Rogatko, Marek [Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, pl. Marii Curie-Sklodowskiej 1 (Poland)

    2010-08-15T23:59:59.000Z

    We prove the uniqueness theorem for the stationary axisymmetric black hole solution in Einstein-Maxwell-axion-dilaton gravity being the low-energy limit of the heterotic string theory. We consider both the nonextremal and extremal Kerr-Sen black hole solutions.

  3. Characterization of oil transport in the power cylinder of internal combustion engines during steady state and transient operation

    E-Print Network [OSTI]

    Przesmitzki, Steve (Steve Victor)

    2008-01-01T23:59:59.000Z

    Engine friction, wear, and oil consumption are some of the primary interests for the automotive industry. However, there is currently a lack of understanding of the fundamentals involving oil transport inside the power ...

  4. First result of the experimental search for the 9.4 keV solar axion reactions with Kr-83 in the copper proportional counter

    E-Print Network [OSTI]

    Yu. M. Gavrilyuk; A. M. Gangapshev; A. V. Derbin; V. V. Kazalov; H. J. Kim; Y. D. Kim; V. V. Kobychev; V. V. Kuzminov; Luqman Ali; V. N. Muratova; S. I. Panasenko; S. S. Ratkevich; D. A. Semenov; D. A. Tekueva; S. P. Yakimenko; E. V. Unzhakov

    2014-05-06T23:59:59.000Z

    The experimental search for solar hadronic axions is started at the Baksan Neutrino Observatory of the Institute for Nuclear Researches Russian Academy of Science. It is assumed that axions are created in the Sun during M1-transition between the first thermally excited level at 9.4 keV and the ground state in Kr-83. The experiment is based on axion detection via resonant absorption process by the same nucleus in the detector. The big copper proportional counter filled with krypton is used to detect signals from axions. The experimental setup is situated in the deep underground low background laboratory. No evidence of axion detection were found after the 26.5 days data collection. Resulting new upper limit on axion mass is m_{A} < 130 eV at 95% C.L.

  5. Solar powered desalination system

    E-Print Network [OSTI]

    Mateo, Tiffany Alisa

    2011-01-01T23:59:59.000Z

    are many solar photovoltaic power plants internationally andUSA, Blythe, CA Solar electric power plant, Blythe USA, SanTX Blue Wing solar electric power plant USA, Jacksonville,

  6. Report of a workshop on nuclear power growth and nonproliferation held at the Woodrow Wilson international center for scholars, Washington, DC, April 21, 2010

    SciTech Connect (OSTI)

    Pilat, Joseph F [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    The workshop addressed the future of nuclear power and nonproliferation in light of global nuclear energy developments, changing US policy and growing concerns about nuclear proliferation and terrorism. The discussion reflected wide agreement on the need for nuclear power, the necessity of mitigating any proliferation and terrorism risks and support for international cooperation on solutions. There were considerable differences on the nature and extent of the risks of differing fuel cycle choices. There was some skepticism about the prospects for a global nuclear energy renaissance, but there was a recognition that nuclear power would expand somewhat in the decades ahead with some states expanding capacity dramatically (e.g., China) and at least a few new states developing nuclear power programs. It was also argued by some participants that under the right conditions, a genuine renaissance could occur some decades from now. The prospects for a dramatic growth in nuclear power will depend on the ability of governments and industry to address these concerns, including the effectiveness of, and the resources devoted to, plans to develop and implement technologies and approaches that strengthen nonproliferation, nuclear materials accountability and nuclear security Several participants noted that the United States will not be able to continue to lead global nonproliferation efforts and to shape the growth of nuclear power as well as the global environment and energy debates without a robust US nuclear energy program. Some participants argued that fully integrating nuclear energy growth and nonproliferation, proliferation resistance and physical protection objectives was possible. The growing consensus on these objectives and the growing concern about the potential impact of further proliferation on the industry was one reason for optimism. The Blue Ribbon commission led by Scowcroft and Hamilton was seen as going far beyond the need to find an alternative to Yucca Mountain, and the preeminent forum in the next years to address the back end of the fuel cycle and other issues. Some argued that addressing these issues is the critical missing element, or the final piece of the puzzle to ensure the benefits of nuclear power and to promote nonproliferation. In this context, many argued that R&D on closed as well as open fuel cycle options in order to ensure a suite of long-term options was essential.

  7. Proceedings of the 2. MIT international conference on the next generation of nuclear power technology. Final report

    SciTech Connect (OSTI)

    NONE

    1993-12-31T23:59:59.000Z

    The goal of the conference was to try to attract a variety of points of view from well-informed people to debate issues concerning nuclear power. Hopefully from that process a better understanding of what one should be doing will emerge. In organizing the conference lessons learned from the previous one were applied. A continuous effort was made to see to it that the arguments for the alternatives to nuclear power were given abundant time for presentation. This is ultimately because nuclear power is going to have to compete with all of the energy technologies. Thus, in discussing energy strategy all of the alternatives must be considered in a reasonable fashion. The structure the conference used has seven sessions. The first six led up to the final session which was concerned with what the future nuclear power strategy should be. Each session focused upon a question concerning the future. None of these questions has a unique correct answer. Rather, topics are addressed where reasonable people can disagree. In order to state some of the important arguments for each session`s question, the combination of a keynote paper followed by a respondent was used. The respondent`s paper is not necessarily included to be a rebuttal to the keynote; but rather, it was recognized that two people will look at a complex question with different shadings. Through those two papers the intention was to get out the most important arguments affecting the question for the session. The purpose of the papers was to set the stage for about an hour of discussion. The real product of this conference was that discussion.

  8. On Axion's Effect on Propagation of Monochromatic Electromagnetic Wave Through Strong Magnetic Field

    E-Print Network [OSTI]

    Mikhail Khankhasayev; Carol Scarlett

    2012-02-07T23:59:59.000Z

    A possibility of detecting the effect of photon-axion mixing in a cavity experiment is discussed. There are two photon-axion modes that acquire different indices of refraction and split in an inhomogeneous magnetic field. For a magnetic field inhomogeneous in the direction transverse to the light propagation an analytical solution is obtained both for the index of refraction and the beams' trajectories. In a cavity experiment, the beam splitting creates a bifurcation effect, which results in a decrease of the light intensity in the central region. Modulation of magnetic field can separate this effect from background by providing a narrow frequency range for any observed signal. When one integrates this effect over time and accounts for bandwidth, the overall drop in FWHM intensity is of order 10-2%. This is a very measurable effect.

  9. Supersymmetry and dark matter post LHC8: Why we may expect both axion and WIMP detection

    SciTech Connect (OSTI)

    Baer, Howard [Dep't of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2014-01-01T23:59:59.000Z

    In the post-LHC8 era, it is perceived that what is left of SUSY model parameter space is highly finetuned in the EW sector (EWFT). We discuss how conventional measures overestimate EWFT in SUSY theory. Radiatively-driven natural SUSY (RNS) models maintain the SUSY GUT paradigm with low EWFT at 10% level, but are characterized by light higgsinos ~100–300 GeV and a thermal underabundance of WIMP dark matter. Implementing the SUSY DFSZ solution to the strong CP problem explains the small ? parameter but indicates dark matter should be comprised mainly of axions with a small admixture of higgsino-like WIMPs. While RNS might escape LHC14 searches, we would expect ultimately direct detection of both WIMPs and axions. An e?e? collider with ?(s)~500–600 GeV should provide a thorough search for the predicted light higgsinos.

  10. Cyclic Operation of Power Plant: Technical, Operational and Cost Issues -- An International Seminar: Proceedings: ''Two Shifting'' Seminar

    SciTech Connect (OSTI)

    None

    2001-01-01T23:59:59.000Z

    Because of changes in demand and competition within the power industry, fossil fuel plants in many countries are now subject to two-shift operation, that is, generating power for 10-15 hours during the day only, usually in combination with a complete shutdown on weekends. Other fossil-fueled units, although running around the clock, need to follow changes in electricity demand. This mode of functioning, in which temperatures and pressures are never stable for more than a few hours, is referred to as ''cyclic operation of plant.'' The aim of the seminar at which these papers were presented was to identify the basic causes of component and equipment problems in two-shift operation, and to begin to identify procedures that could minimize operating and maintenance costs. The papers cover the following topics: Session 1: Plant Operation Experience and Design Issues; Session 2: Materials Issues; Session 3: Cost, Manpower and Management Issues; Session 4: Plant Automation Issues; Session 5: Hot Section Gas Turbine Issues; and Session 6: HRSG [heat recovery steam generator] Issues.

  11. We need lab experiments to look for axion-like particles

    E-Print Network [OSTI]

    Jaeckel, J; Redondo, J; Ringwald, A; Takahashi, F; Jaeckel, Joerg; Masso, Eduard; Redondo, Javier; Ringwald, Andreas; Takahashi, Fuminobu

    2006-01-01T23:59:59.000Z

    The PVLAS signal has renewed the interest in light bosons coupled to the electromagnetic field. However, astrophysical bounds coming from the lifetime of the sun and the CAST experiment are seemingly in conflict with this result. We discuss effective models that allow to suppress production of axion-like particles in the sun and thereby relax the bounds by some orders of magnitude. This stresses the importance of laboratory searches.

  12. On the energy of charged black holes in generalized dilaton-axion gravity

    E-Print Network [OSTI]

    I. Radinschi; Farook Rahaman; Asish Ghosh

    2010-03-15T23:59:59.000Z

    In this paper we calculate the energy distribution of some charged black holes in generalized dilaton-axion gravity. The solutions correspond to charged black holes arising in a Kalb-Ramond-dilaton background and some existing non-rotating black hole solutions are recovered in special cases. We focus our study to asymptotically flat and asymptotically non-flat types of solutions and resort for this purpose to the M{\\o}ller prescription. Various aspects of energy are also analyzed.

  13. The Milky Way's Dark Matter Distribution and Consequences for Axion Detection

    SciTech Connect (OSTI)

    Duffy, Leanne D. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545 (United States)

    2010-08-30T23:59:59.000Z

    Signals for both direct and indirect dark matter detection depend on the phase-space distribution of dark matter. The possibility of structures with high physical density, known as caustics, has provided an opportunity to increase the discovery potential of the Axion Dark Matter eXperiment (ADMX). I discuss the formation of dark matter caustics and consequences of the caustic ring model for ADMX.

  14. String solutions in Chern-Simons-Higgs model coupled to an axion

    E-Print Network [OSTI]

    J. Lopez-Sarrion; E. F. Moreno; F. A. Schaposnik; D. Slobinsky

    2006-03-11T23:59:59.000Z

    We study a d=2+1 dimensional Chern-Simons gauge theory coupled to a Higgs scalar and an axion field, finding the form of the potential that allows the existence of selfdual equations and the corresponding Bogomolny bound for the energy of static configurations. We show that the same conditions allow for the N=2 supersymmetric extension of the model, reobtaining the BPS equations from the supersymmetry requirement. Explicit electrically charged vortex-like solutions to these equations are presented.

  15. The Milky Way's dark matter distribution and consequences for axion detection

    SciTech Connect (OSTI)

    Duffy, Leanne D [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    Signals for both direct and indirect dark matter detection depend on the phase-space distribution of dark matter. The possibility of structures with high physical density, known as caustics, has provided an opportunity to increase the discovery potential of the Axion Dark Matter eXperiment (ADMX). I discuss the formation of dark matter caustics and consequences of the caustic ring model for ADMX.

  16. Test and demonstration of a 1-MW wellhead generator: helical screw expander power plant, Model 76-1. Final report to the International Energy Agency

    SciTech Connect (OSTI)

    Not Available

    1985-07-04T23:59:59.000Z

    A 1-MW geothermal wellhead power plant incorporating a Lysholm or helical screw expander (HSE) was field tested between 1980 and 1983 by Mexico, Italy, and New Zealand with technical assistance from the United States. The objectives were to provide data on the reliability and performance of the HSE and to assess the costs and benefits of its use. The range of conditions under which the HSE was tested included loads up to 933 kW, mass flowrates of 14,600 to 395, 000 lbs/hr, inlet pressures of 64 to 220 psia, inlet qualities of 0 to 100%, exhaust pressures of 3.1 to 40 psia, total dissolved solids up to 310,000 ppM, and noncondensible gases up to 38% of the vapor mass flow. Typical machine efficiencies of 40 to 50% were calculated. For most operations efficiency increased approximately logarithmically with shaft power, while inlet quality and rotor speed had only small effects. The HSE was designed with oversized internal clearances in the expectation that adherent scale would form during operation. Improvements in machine efficiency of 3.5 to 4 percentage points were observed over some test periods with some scale deposition. A comparison with a 1-MW back-pressure turbine showed that the HSE can compete favorably under certain conditions. The HSE was found to be a rugged energy conversion machine for geothermal applications, but some subsystems were found to require further development. 7 refs., 28 figs., 5 tabs.

  17. Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

    SciTech Connect (OSTI)

    Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

    2009-06-30T23:59:59.000Z

    This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown disposal. Membrane treatment (nanofiltration or reverse osmosis) can be employed to reduce TDS and sulfate concentrations to acceptable levels for reuse of the blowdown in the cooling systems as makeup water.

  18. International Conference on Human Resource Development for Nuclear Power Programmes: Strategies for Education and Training, Networking and Knowledge Management

    SciTech Connect (OSTI)

    Pepper, S.

    2014-06-24T23:59:59.000Z

    The IAEA’s Junior Professional Officer (JPO) program provides the opportunity for early career professionals to obtain valuable work experience while helping the IAEA perform basic, yet essential work that would otherwise be performed by an experienced staff member. JPO assignments span the spectrum of IAEA tasks, including open source information collection and analysis, equipment evaluation, testing, and installation, statistical analysis of data, software and web development, entomology, performance strategy, project management, communications, and stable isotope analysis. JPOs are college graduates with degrees in science, engineering, or other disciplines relevant to the work of the IAEA, generally 32 years old or younger, and have approximately two years’ professional experience. They work with the IAEA in entry-level positions for one or two years under extrabudgetary funding provided by an IAEA Member State. Currently, ten Member States have JPO agreements with the IAEA. The United States initiated its JPO program in 2004 and has found that the program has advantages for both the IAEA and the United States. The IAEA is an excellent environment for introducing young scientists, engineers and other professionals to the practical application of their education, to international civil service, to the challenges facing the global nuclear industry, and to the industry’s practitioners. This paper will summarize the advantages of the JPO program to the IAEA and to the Member State.

  19. Nuclear Instruments and Methods in Physics Research A 425 (1999) 480--487 A decommissioned LHC model magnet as an axion telescope

    E-Print Network [OSTI]

    Collar, Juan I.

    Laboratorio de Fisica Nuclear y Atlas Energias, Faculdad de Ciencias, Universidad de Zaragoza, E50009 Zaragoza LHC bending magnet can be utilized as a macroscopic coherent solar axion-to-photon converter.V. All rights reserved. PACS: 41.85.Lc; 85.25.Ly; 14.80.-j; 14.80.Mz; 92.60.Vb; 95 Keywords: Solar axions

  20. INTERNATIONAL International Internship for

    E-Print Network [OSTI]

    Napier, Terrence

    OFFICE OF INTERNATIONAL AFFAIRS International Internship for Global Leadership Program Student Portugal ­ Laura Sieger Ukraine ­ Mary Brune 2012 Internship Locations #12;Dear Friends and Colleagues of Lehigh University: The International Internship for Global Leadership Program provides Lehigh students

  1. Feasibility Study for Measuring Geomagnetic Conversion of Solar Axions to X-rays in Low Earth Orbits

    E-Print Network [OSTI]

    Davoudiasl, Hooman

    2008-01-01T23:59:59.000Z

    We present a detailed computation of the expected rate for Geomagnetic Conversion of Solar Axions to X-rays (GECOSAX) along the orbit of an x-ray satellite. We use realistic satellite orbits and propagation in time. A realistic model for the Earth's magnetic field, which properly accounts for its spatial non-uniformity, is used. We also account for the effect of the Earth's atmosphere on the propagation of x-rays in our calculation of axion-photon conversion probability. To estimate possible sensitivities to the axion-photon coupling g_{a\\gamma}, we use an actual measurement of the expected backgrounds by the SUZAKU satellite. Assuming a detector area of 10^3 cm^2 and about 10^6 s of data, we show that a 2 \\sigma limit of g_{a\\gamma} current laboratory sensitivities to g_{a\\gamma}.

  2. Feasibility Study for Measuring Geomagnetic Conversion of Solar Axions to X-rays in Low Earth Orbits

    E-Print Network [OSTI]

    Hooman Davoudiasl; Patrick Huber

    2009-03-20T23:59:59.000Z

    We present a detailed computation of the expected rate for Geomagnetic Conversion of Solar Axions to X-rays (GECOSAX) along the orbit of an x-ray satellite. We use realistic satellite orbits and propagation in time. A realistic model for the Earth's magnetic field, which properly accounts for its spatial non-uniformity, is used. We also account for the effect of the Earth's atmosphere on the propagation of x-rays in our calculation of axion-photon conversion probability. To estimate possible sensitivities to the axion-photon coupling g_{a\\gamma}, we use an actual measurement of the expected backgrounds by the SUZAKU satellite. Assuming a detector area of 10^3 cm^2 and about 10^6 s of data, we show that a 2 \\sigma limit of g_{a\\gamma} current laboratory sensitivities to g_{a\\gamma}.

  3. International reservoir operations agreement helps NW fish &...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    or 503-230-5131 International reservoir operations agreement helps Northwest fish and power Portland, Ore. - The Bonneville Power Administration and the British Columbia...

  4. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix I, Volume 2, Part 5

    SciTech Connect (OSTI)

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J. [Brookhaven National Lab., Upton, NY (United States); Bley, D.; Johnson, D. [PLG Inc., Newport Beach, CA (United States); Holmes, B. [AEA Technology, Dorset (United Kingdom)] [and others

    1994-06-01T23:59:59.000Z

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Lab. (BNL) and Sandia National Labs. (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this volume of the report is to document the approach utilized in the level-1 internal events PRA for the Surry plant, and discuss the results obtained. A phased approach was used in the level-1 program. In phase 1, which was completed in Fall 1991, a coarse screening analysis examining accidents initiated by internal events (including internal fire and flood) was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis.

  5. International energy annual 1996

    SciTech Connect (OSTI)

    NONE

    1998-02-01T23:59:59.000Z

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power, geothermal, solar, and wind electric power, biofuels energy for the US, and biofuels electric power for Brazil. New in the 1996 edition are estimates of carbon dioxide emissions from the consumption of petroleum and coal, and the consumption and flaring of natural gas. 72 tabs.

  6. Comparison of Test Procedures and Energy Efficiency Criteria in Selected International Standards & Labeling Programs for Copy Machines, External Power Supplies, LED Displays, Residential Gas Cooktops and Televisions

    E-Print Network [OSTI]

    Zheng, Nina

    2013-01-01T23:59:59.000Z

    external-power- supplies/meps/ Australia E3. 2012. “EU, Australia and Japan all have maximum power consumptionEU, Australia and Japan all have maximum power consumption

  7. Axionic Antiferromagnetic Insulator Phase in a Correlated and Spin-Orbit Coupled System

    E-Print Network [OSTI]

    Akihiko Sekine; Kentaro Nomura

    2014-09-24T23:59:59.000Z

    We study theoretically a three-dimensional correlated and spin-orbit coupled system, the half-filled extended Fu-Kane-Mele-Hubbard model on a diamond lattice, focusing on the topological magnetoelectric response of the antiferromagnetic insulator phase. In the antiferromagnetic insulator phase, the Dirac-like low-energy effective Hamiltonian is obtained. Then the theta term, which results in the magnetoelectric response, is derived as a consequence of the chiral anomaly. The realization of the dynamical axion field in our model is discussed. The relation with a symmetry broken phase induced by interactions in lattice quantum chromodynamics is also discussed.

  8. Quantum corrections to the entropy of Einstein-Maxwell dilaton-axion black holes

    E-Print Network [OSTI]

    M. Akbar; K. Saifullah

    2010-02-20T23:59:59.000Z

    We study the corrections to the entropy of Einstein-Maxwell dilaton-axion black holes beyond semiclassical approximations. We consider the entropy of the black hole as a state variable and derive these corrections using the exactness criteria of the first law of thermodynamics. We note that from this general frame-work the entropy corrections for "simpler" black holes like Schwarzschild, Reissner-Nordstr\\"{o}m and anti-de Sitter-Schwarzschild black holes follow easily. This procedure gives us the modified area law as well.

  9. Stability of Non-asymptotically flat thin-shell wormholes in generalized dilaton-axion gravity

    E-Print Network [OSTI]

    Ayan Banerjee; Farook Rahaman; Surajit Chattopadhyay; Sumita Banerjee

    2013-04-11T23:59:59.000Z

    We construct a new type of thin-shell wormhole for non-asymptotically flat charged black holes in generalized dilaton-axion gravity inspired by low-energy string theory using cut-and-paste technique. We have shown that this thin shell wormhole is stable. The most striking feature of our model is that the total amount of exotic matter needed to support the wormhole can be reduced as desired with the suitable choice of the value of a parameter. Various other aspects of thin-shell wormhole are also analyzed.

  10. R-Axion: A New LHC Physics Signature Involving Muon Pairs

    SciTech Connect (OSTI)

    Goh, Hock-Seng; /UC, Berkeley /LBL, Berkeley; Ibe, Masahiro; /SLAC

    2012-04-12T23:59:59.000Z

    In a class of models with gauge mediated supersymmetry breaking, the existence of a light pseudo scalar particle, R-axion, with a mass in hundreds MeV range is predicted. The striking feature of such a light R-axion is that it mainly decays into a pair of muons and leaves a displaced vertex inside detectors once it is produced. In this talk, we show how we can search for the R-axion at the coming LHC experiments. The one main goal of the LHC experiments is discovering supersymmetry which has been anticipated for a long time to solve the hierarchy problem. Once the supersymmetric standard model (SSM) is confirmed experimentally, the next question is how the supersymmetry is broken and how the effects of symmetry breaking are mediated to the SSM sector. In most cases, such investigations on 'beyond the SSM physics' rely on arguments based on extrapolations of the observed supersymmetry mass parameters to higher energies. However, there is one class of models of supersymmetry breaking where we can get a direct glimpse of the structure of the hidden sector with the help of the R-symmetry. The R-symmetry plays an important role in rather generic models of spontaneous supersymmetry breaking. At the same time, however, it must be broken in some way in order for the gauginos in the SSM sector to have non-vanishing masses. One possibility of the gaugino mass generation is to consider models where the gaugino masses are generated as a result of the explicit breaking of the R-symmetries. Unfortunately, in those models, the R-symmetry leaves little trace for the collider experiments, since the mass of the R-axion is typically heavy and beyond the reach of the LHC experiments. In this talk, instead, we consider a class of models with gauge mediation where the R-symmetry in the hidden/messenger sectors is exact in the limit of the infinite reduced Planck scale, i.e. M{sub PL} {yields} {infinity}. In this case, the gaugino masses are generated only after the R-symmetry is broken spontaneously. We also assume that the R-symmetry is respected by the SSM sector as well as the origin of the higgsino mass {mu} and the Higgs mass mixing B{mu} at the classical level. We call this scenario, the minimal R-symmetry breaking scenario.

  11. Identification of Severe Multiple Contingencies in Electric Power Systems

    E-Print Network [OSTI]

    Donde, Vaibhav; Lopez, Vanessa; Lesieutre, Bernard; Pinar, Ali; Yang, Chao; Meza, Juan

    2008-01-01T23:59:59.000Z

    collapse in electrical power systems,” IEEE Transactions onpower sys- tems,” International Journal of Electrical Power and Energy Systems,

  12. Identification of Severe Multiple Contingencies in Electric Power Systems

    E-Print Network [OSTI]

    Donde, Vaibhav

    2010-01-01T23:59:59.000Z

    collapse in electrical power systems,” IEEE Transactions onpower sys- tems,” International Journal of Electrical Power and Energy Systems,

  13. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix E (Sections E.9-E.16), Volume 2, Part 3B

    SciTech Connect (OSTI)

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Wong, S.M. [Brookhaven National Lab., Upton, NY (United States); Bley, D.; Johnson, D. [PLG Inc., Newport Beach, CA (United States)] [and others

    1994-06-01T23:59:59.000Z

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis.

  14. Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendices F-H, Volume 2, Part 4

    SciTech Connect (OSTI)

    Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J. [Brookhaven National Lab., Upton, NY (United States); Bley, D.; Johnson, D. [PLG Inc., Newport Beach, CA (United States); Holmes, B. [AEA Technology, Dorset (United Kingdom)] [and others

    1994-06-01T23:59:59.000Z

    Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis.

  15. Space-time singularities and the axion in the Poincare coset models ISO(2,1)/H

    E-Print Network [OSTI]

    Roberto Casadio; Benjamin Harms

    1996-06-12T23:59:59.000Z

    By promoting an invariant subgroup $H$ of $ISO(2,1)$ to a gauge symmetry of a WZWN action, we obtain the description of a bosonic string moving either in a curved 4-dimensional space--time with an axion field and curvature singularities or in 3-dimensional Minkowski space--time.

  16. A COSMIC AXION DETECTOR* C. Hagmann, P. Sikivie, N.S. Sullivan and D.B. Tanner

    E-Print Network [OSTI]

    Tanner, David B.

    into one photon in the presence of a static background field B0. Axion to photon conversion is greatly OFHCCucavley } superconducelng IB = 9,5 T Magne~ IOHHz kO )______~ Mixer TLF AMp I I Fig.l: schematic diagram

  17. Axion-Higgs interplay in the two Higgs-doublet model

    E-Print Network [OSTI]

    Espriu, Domenec; Renau, Albert

    2015-01-01T23:59:59.000Z

    We study the Dine-Fischler-Srednicki (DFS) model in the light of the recent Higgs LHC results and electroweak precision data. The DFS model is a natural extension of the two-Higgs doublet model endowed with a Peccei-Quinn symmetry and leading to a physically acceptable axion. For generic couplings, the model reproduces the minimal Standard Model showing only tiny deviations (extreme decoupling scenario) whereas all additional degrees of freedom (with the exception of the axion) are very heavy. Recently, new corners of this model have been highlighted where it may exhibit enlarged global symmetries making the corresponding models technically natural (naturalness scenario). In some cases an additional Higgs could be present at the weak scale. In this case, the new light $0^+$ state would be accompanied by relatively light charged and neutral pseudoscalar Higgses. We will use the oblique corrections, particularly $\\Delta\\rho$, to constrain the mass spectrum in this case. As a final result, we also work out the n...

  18. Constraining interactions mediated by axion-like particles with ultracold neutrons

    E-Print Network [OSTI]

    S. Afach; G. Ban; G. Bison; K. Bodek; M. Burghoff; M. Daum; M. Fertl; B. Franke; Z. D. Gruji?; V. Hélaine; M. Kasprzak; Y. Kermaïdic; K. Kirch; P. Knowles; H. -C. Koch; S. Komposch; A. Kozela; J. Krempel; B. Lauss; T. Lefort; Y. Lemière; A. Mtchedlishvili; O. Naviliat-Cuncic; F. M. Piegsa; G. Pignol; P. N. Prashanth; G. Quéméner; D. Rebreyend; D. Ries; S. Roccia; P. Schmidt-Wellenburg; A. Schnabel; N. Severijns; J. Voigt; A. Weis; G. Wyszynski J. Zejma; J. Zenner; G. Zsigmond

    2014-12-11T23:59:59.000Z

    We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms confined in the same volume. The measurement was performed in a $\\sim$1$\\mu$ T vertical magnetic holding field with the apparatus searching for a permanent electric dipole moment of the neutron at the Paul Scherrer Institute. A possible coupling between freely precessing polarized neutron spins and unpolarized nucleons of the wall material can be investigated by searching for a tiny change of the precession frequencies of neutron and mercury spins. Such a frequency change can be interpreted as a consequence of a short range spin-dependent interaction that could possibly be mediated by axions or axion-like particles. The interaction strength is proportional to the CP violating product of scalar and pseudoscalar coupling constants $g_Sg_P$. Our result confirms limits from complementary experiments with spin-polarized nuclei in a model-independent way. Limits from other neutron experiments are improved by up to two orders of magnitude in the interaction range of $10^{-6}<\\lambda<10^{-4}$ m.

  19. SO(10) SUSY GUTs with mainly axion cold dark matter: implications for cosmology and colliders

    SciTech Connect (OSTI)

    Baer, Howard [Dept. of Physics and Astronomy, University of Oklahoma, Norman, OK, 73019 (United States)

    2010-08-30T23:59:59.000Z

    Supersymmetric grand unified theories based on the gauge group SO(10) are highly motivated. In the simplest models, one expects t--b--{tau} Yukawa coupling unification, in addition to gauge, matter and Higgs unification. Yukawa unification only occurs with very special GUT scale boundary conditions, leading to a spectra with {approx} 10 TeV first and second generation scalars, TeV-scale third generation scalars, and light gauginos. The relic density of neutralino cold dark matter is calculated to be 10{sup 2}-10{sup 4} times higher than observation. If we extend the theory with the PQ solution to the strong CP problem, then instead a mixture of axions and axinos comprises the dark matter, with the measured abundance. Such a solution solves several cosmological problems. We predict a rather light gluino with m{sub g}-tilde{approx}300-500 GeV that should be visible in either Tevatron or forthcoming LHC run 1 data. We would also expect ultimately a positive result from relic axion search experiments.

  20. International Programs in Agriculture

    E-Print Network [OSTI]

    International Programs in Agriculture MessagefromtheDirector­ Staying Ahead of Globalization and more prosperous place for all. Fortunately, Purdue International Programs in Agriculture (IPIA) has natural disasters caution us to remember the power of nature. The United Nations Food and Agriculture

  1. International Conference

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other NewsSpinInteragency1Princeton PlasmaInternationalA

  2. International H

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergy International Fuel Services and Commercial2

  3. International Sunport

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn OtherEnergy International Fuel Services»Challenges

  4. Rotating Black Hole Solutions with Axion Dilaton and Two Vector Fields and Solutions with Metric and Fields of the Same Form

    E-Print Network [OSTI]

    E. Kyriakopoulos

    2009-05-15T23:59:59.000Z

    We present two rotating black hole solutions with axion $\\xi$, dilaton $\\phi$ and two U(1) vector fields. By applying the "Newman-Janis trick" to a metric with 3 arbitrary parameters we find a rotating metric $g_{\\mu\

  5. New limit on the mass of 14.4-keV solar axions emitted in an M1 transition in {sup 57}Fe nuclei

    SciTech Connect (OSTI)

    Derbin, A. V., E-mail: derbin@pnpi.spb.ru; Muratova, V. N.; Semenov, D. A.; Unzhakov, E. V. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation)

    2011-04-15T23:59:59.000Z

    Axions of energy 14.4 keV that originated from the M1 transition in {sup 57}Fe nuclei in the Sun were sought by using the resonance-absorption reaction A+{sup 57}Fe {yields} {sup 57}Fe* {yields} {sup 57}Fe+{gamma} (14.4 keV). Asectioned Si(Li) detector arranged in a low-background facility was used to record photons from this reaction. This resulted in setting a new limit on the axion couplings to nucleons, vertical bar -1.19g{sub AN}{sup 0} + g{sub AN}{sup 3} vertical bar {<=} 3.0 Multiplication-Sign 10{sup -6}. Within the hadronic-axion model, the respective constraint on the axion mass is m{sub A} {<=} 145 eV (at a 95% C.L.).

  6. Search for 14.4-KeV Solar Axions Emitted in the M1-Transition of Fe-57 Nuclei with CAST

    SciTech Connect (OSTI)

    Andriamonje, S.; Aune, S.; /DAPNIA, Saclay; Autiero, D.; /CERN /Lyon, IPN; Barth, K.; /CERN; Belov, A.; /Moscow, INR; Beltran, B.; /Zaragoza U. /Queen's U., Kingston; Brauninger, H.; /Garching, Max Planck Inst., MPE; Carmona, J.M.; Cebrian, S.; /Zaragoza U.; Collar, J.I.; /Chicago U., EFI /Chicago U., KICP; Dafni, T.; /DAPNIA, Saclay /Darmstadt, Tech. Hochsch. /Zaragoza U.; Davenport, M.; /CERN; Di Lella, L.; /CERN /Pisa, Scuola Normale Superiore; Eleftheriadis, C.; /Aristotle U., Thessaloniki; Englhauser, J.; /Garching, Max Planck Inst., MPE; Fanourakis, G.; /Democritos Nucl. Res. Ctr.; Ferrer-Ribas, E.; /DAPNIA, Saclay; Fischer, H.; Franz, J.; /Freiburg U.; Friedrich, P.; /Garching, Max Planck Inst., MPE; Geralis, T.; /Democritos Nucl. Res. Ctr. /DAPNIA, Saclay /Moscow, INR /Zaragoza U. /British Columbia U. /Freiburg U. /Darmstadt, Tech. Hochsch. /DAPNIA, Saclay /Zaragoza U. /Frankfurt U. /Boskovic Inst., Zagreb /Freiburg U. /Munich, Max Planck Inst. /Boskovic Inst., Zagreb /Democritos Nucl. Res. Ctr. /Darmstadt, Tech. Hochsch. /Garching, Max Planck Inst., MPE /Boskovic Inst., Zagreb /CERN /Aristotle U., Thessaloniki /Boskovic Inst., Zagreb /Munich, Max Planck Inst. /Zaragoza U. /Chicago U., EFI /Chicago U., KICP /Stanford U., Phys. Dept. /SLAC /Zaragoza U. /CERN /DAPNIA, Saclay /CERN /Munich, Max Planck Inst. /Darmstadt, Tech. Hochsch. /Zaragoza U. /Aristotle U., Thessaloniki /Patras U. /Brookhaven /CERN /Munich, Max Planck Inst. /CERN /Chicago U., EFI /Chicago U., KICP /Zaragoza U. /Freiburg U. /CERN /CERN /Patras U.

    2011-12-02T23:59:59.000Z

    We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g{sub ay}|-1.19g{sub aN}{sup 0}+g{sub aN}{sup 3}| < 1.36 x 10{sup -16} GeV{sup -1} for ma < 0.03 eV at the 95% confidence level.

  7. Thermionic power generation. January 1972-December 1980 (citations from the International Aerospace Abstracts Data Base). Report for January 1972-December 1980

    SciTech Connect (OSTI)

    Not Available

    1980-12-01T23:59:59.000Z

    Research on thermionic power generation, power plant design, converter design, and basic research on thermionic materials are cited in the bibliography. Spacecraft applications are also included. (Contains 142 citations, fully indexed and including a table of contents.)

  8. International Journal of Systems Science, 2000, volume 31, number 4, pages 519 527 Multi machine power system excitation control design via theories

    E-Print Network [OSTI]

    Qu, Zhihua

    . Controllers designed using modern state-space theory have been serving power systems for decades power system excitation control design via theories of feedback linearization control and nonlinear robust control DEQIANG GAN{, ZHIHUA QU{ and HONGZHI CAI{ The dynamics of a large-scale power system

  9. Space Science Technology Health General Sci-fi & Gaming Oddities International Business Politics Education Entertainment Sports Solar Power With A Twist

    E-Print Network [OSTI]

    Rogers, John A.

    Education Entertainment Sports Solar Power With A Twist Posted on: Monday, 6 October 2008, 07:25 CDT Solar-Champaign Source: redOrbit Staff & Wire Reports More News in this Category Related Articles Solar Power Showcased power is now available with a twist, thanks to U.S. researchers who found a way to make efficient

  10. 532 2007 IEEE International Solid-State Circuits Conference ISSCC 2007 / SESSION 29 / ANALOG AND POWER MANAGEMENT TECHNIQUES / 29.8

    E-Print Network [OSTI]

    Lemieux, Guy

    ) and clock-tree charge-recycling are used to further reduce power loss and improve conversion efficiency was previously used in [1], in which a clock resonance scheme reduces power loss in the clock network. In comparison, we use charge recycling and ZVS to decrease clock power loss. Figure 29.8.1 shows the block

  11. Hawaii International Conference on System Sciences, January 3-6, 2001, Maui, Hawaii. 2001 IEEE Modeling Blackout Dynamics in Power Transmission Networks

    E-Print Network [OSTI]

    in electric power transmission systems is implemented and studied in simple networks with a regular structure dynamics of cascading overloads and outages. The model dynamics are demonstrated on the simple power system Electric power transmission systems are complex engineering systems with many interacting components

  12. Hawaii International Conference on System Sciences, January 2001, Maui, Hawaii. c 2001 IEEE An initial model for complex dynamics in electric power system blackouts

    E-Print Network [OSTI]

    Newman, David

    An initial model for complex dynamics in electric power system blackouts I. Dobson ECE Department University of electric power transmission system blackouts. The model describes opposing forces which have been conjectured to cause self-organized criticality in power system blackouts. There is a slow time scale

  13. International Policy International Development

    E-Print Network [OSTI]

    Watson, Andrew

    Research Strategy 2006-2009 International Policy Energy Adaptation International Development Coasts Change Research. Our strategy builds upon our previous work on integrated assessment, energy, adaptation of time. In this spirit, the Centre reconfirms its vision statement: "The Tyndall Centre is the UK network

  14. Accepted for publication in Proceedings of IEEE International Conference on Communications, June 2001 A Novel Co-existence Algorithm for Unlicensed Variable Power Devices

    E-Print Network [OSTI]

    Peha, Jon M.

    ], the Federal Communications Commission (FCC) has created several unlicensed bands, such as the IndustryAccepted for publication in Proceedings of IEEE International Conference on Communications, June, Science and Medicine (ISM) bands, the Unlicensed Personal Communication Services (UPCS) band [2

  15. Axion-Like Particle Imprint in Cosmological Very-High-Energy Sources

    SciTech Connect (OSTI)

    Dominguez, A.; /Seville U. /IAA, Granada /Madrid, Autonoma U.; Sanchez-Conde, M.A.; /IAC, La Laguna /IAC, La Laguna /KIPAC, Menlo Park /SLAC; Prada, F.; /IAA, Granada

    2012-06-13T23:59:59.000Z

    Discoveries of very high energy (VHE) photons from distant blazars suggest that, after correction by extragalactic background light (EBL) absorption, there is a flatness or even a turn-up in their spectra at the highest energies that cannot be easily explained by the standard framework. Here, it is shown that a possible solution to this problem is achieved by assuming the existence of axion-like particles (ALPs) with masses {approx} 1 neV. The ALP scenario is tested making use of observations of the highest redshift blazars known in the VHE energy regime, namely 3C 279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to the observed spectra are found when including ALPs rather than considering EBL only. Interestingly, quite similar critical energies for photon/ALP conversions are also derived, independently of the source considered.

  16. Hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion black holes

    E-Print Network [OSTI]

    Deyou Chen; Hui Wang; Houwen Wu; Haitang Yang

    2010-10-19T23:59:59.000Z

    The hidden conformal symmetry of extreme and non-extreme Einstein-Maxwell-Dilaton-Axion (EMDA) black holes is addressed in this paper. For the non-extreme one, employing the wave equation of massless scalars, the conformal symmetry with left temperature $T_{L}=\\frac{M}{2\\pi a}$ and right temperature $T_{R}=\\frac{\\sqrt{M^{2}-a^{2}}}{2\\pi a}$ in the near region is found. The conformal symmetry is spontaneously broken due to the periodicity of the azimuthal angle. The microscopic entropy is derived by the Cardy formula and is fully in consistence with the Bekenstein-Hawking area-entropy law. The absorption cross section in the near region is calculated and exactly equals that in a 2D CFT. For the extreme case, by redefining the conformal coordinates, the duality between the solution space and CFT is studied. The microscopic entropy is found to exactly agree with the area-entropy law.

  17. Axion-like particle imprint in cosmological very-high-energy sources

    SciTech Connect (OSTI)

    Domínguez, A. [Dpto. de FAMN, Universidad de Sevilla, Apdo. Correos 1065, E-41080 Sevilla (Spain); Sánchez-Conde, M.A. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Prada, F., E-mail: alberto@iaa.es, E-mail: masc@stanford.edu, E-mail: fprada@iaa.es [Instituto de Astrofísica de Andalucía, CSIC, Apdo. Correos 3004, E-18080 Granada (Spain)

    2011-11-01T23:59:59.000Z

    Discoveries of very high energy (VHE) photons from distant blazars suggest that, after correction by extragalactic background light (EBL) absorption, there is a flatness or even a turn-up in their spectra at the highest energies that cannot be easily explained by the standard framework. Here, it is shown that a possible solution to this problem is achieved by assuming the existence of axion-like particles (ALPs) with masses ? 1 neV. The ALP scenario is tested making use of observations of the highest redshift blazars known in the VHE energy regime, namely 3C 279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to the observed spectra are found when including ALPs rather than considering EBL only. Interestingly, quite similar critical energies for photon/ALP conversions are also derived, independently of the source considered.

  18. Power Factor Reactive Power

    E-Print Network [OSTI]

    motor power: 117.7 V x 5.1 A = 600 W? = 0.6 kW? NOT the power measured by meter #12;Page 9 PSERC: displacement power factor: angle between voltage and current = 0 degrees pf = cos(0 degrees) = 1.0 true powerPage 1 PSERC Power Factor and Reactive Power Ward Jewell Wichita State University Power Systems

  19. Published in 39th International Symposium on Computer Architecture, June, 2012 Managing Distributed UPS Energy for Effective Power Capping in Data Centers

    E-Print Network [OSTI]

    Wang, Deli

    the lifetime of the data center (capital expenses, or capex) and monthly recur- ring operating expenses (opex) [22]. Capex costs are pro- portional to the provisioned IT power per facility, estimated at $10-20 per of distributed batteries in the data center to reduce both capex and opex costs. Power infrastructure is commonly

  20. Proceedings of the 2007 IEEE 10th International Conference on Rehabilitation Robotics, June 12-15, Noordwijk, The Netherlands Biomechanical Design of a Powered Ankle-Foot Prosthesis

    E-Print Network [OSTI]

    Herr, Hugh

    -15, Noordwijk, The Netherlands Biomechanical Design of a Powered Ankle-Foot Prosthesis Samuel K. Au, Jeff Weber, and Hugh Herr Abstract-Although the potential benefits of a powered ankle- foot prosthesis have been well documented, no one has suc- cessfully developed and verified that such a prosthesis can improve amputee gait

  1. Large-scale coherent orientations of quasar polarisation vectors: interpretation in terms of axion-like particles

    SciTech Connect (OSTI)

    Payez, A.; Hutsemekers, D.; Cudell, J. R. [University of Liege, Allee du 6 Aout 17, 4000 Liege (Belgium)

    2010-08-30T23:59:59.000Z

    The observation of redshift-dependent coherent orientations of quasar polarisation vectors over cosmological distances in some regions of the sky is reviewed. Based on a good-quality sample of 355 measured quasars, this observation seems to infer the existence of a new effect acting on light propagation on such huge distances.A solution in terms of nearly massless axion-like particles has been proposed in the literature and its current status is discussed.

  2. Reconciling thermal leptogenesis with the gravitino problem in SUSY models with mixed axion/axino dark matter

    SciTech Connect (OSTI)

    Baer, Howard; Lessa, Andre [Dept. of Physics and Astronomy, University of Oklahoma, 440 West Brooks, Norman, OK 73019 (United States); Kraml, Sabine [Laboratoire de Physique Subatomique et de Cosmologie, UJF Grenoble 1, CNRS/IN2P3, INPG, 53 Avenue des Martyrs, F-38026 Grenoble (France); Sekmen, Sezen, E-mail: baer@nhn.ou.edu, E-mail: sabine.kraml@lpsc.in2p3.fr, E-mail: lessa.a.p@gmail.com, E-mail: sezen.sekmen@cern.ch [Dept. of Physics, Florida State University, 513 Keen Bldg., Tallahassee, FL 32306 (United States)

    2010-11-01T23:59:59.000Z

    Successful implementation of thermal leptogenesis requires re-heat temperatures T{sub R}?>2 × 10{sup 9} GeV, in apparent conflict with SUSY models with TeV-scale gravitinos, which require much lower T{sub R} in order to avoid Big Bang Nucleosynthesis (BBN) constraints. We show that mixed axion/axino dark matter can reconcile thermal leptogenesis with the gravitino problem in models with m{sub G-tilde}?>30 TeV, a rather high Peccei-Quinn breaking scale and an initial mis-alignment angle ?{sub i} < 1. We calculate axion and axino dark matter production from four sources, and impose BBN constraints on long-lived gravitinos and neutralinos. Moreover, we discuss several SUSY models which naturally have gravitino masses of the order of tens of TeV. We find a reconciliation difficult in Yukawa-unified SUSY and in AMSB with a wino-like lightest neutralino. However, T{sub R} ? 10{sup 10}?10{sup 12} GeV can easily be achieved in effective SUSY and in models based on mixed moduli-anomaly mediation. Consequences of this scenario include: 1. an LHC SUSY discovery should be consistent with SUSY models with a large gravitino mass, 2. an apparent neutralino relic abundance ?{sub Z-tilde} {sub 1}h{sup 2}?<1, 3. no WIMP direct or indirect detection signals should be found, and 4. the axion mass should be less than ? 10{sup ?6} eV, somewhat below the conventional range which is explored by microwave cavity axion detection experiments.

  3. New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"

    E-Print Network [OSTI]

    R. Ballou; G. Deferne; M. Finger Jr.; M. Finger; L. Flekova; J. Hosek; S. Kunc; K. Macuchova; K. A. Meissner; P. Pugnat; M. Schott; A. Siemko; M. Slunecka; M. Sulc; C. Weinsheimer; J. Zicha

    2015-06-26T23:59:59.000Z

    Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of $2 \\times 14.3$ m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green spectral regime (532 nm). No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit to be less than $3.5\\cdot 10^{-8}$ GeV$^{-1}$ and $3.2\\cdot 10^{-8}$ GeV$^{-1}$, respectively.

  4. New Exclusion Limits for the Search of Scalar and Pseudoscalar Axion-Like Particles from "Light Shining Through a Wall"

    E-Print Network [OSTI]

    Ballou, R; Finger, M; Finger, M; Flekova, L; Hosek, J; Kunc, S; Macuchova, K; Meissner, K A; Pugnat, P; Schott, M; Siemko, A; Slunecka, M; Sulc, M; Weinsheimer, C; Zicha, J

    2015-01-01T23:59:59.000Z

    Physics beyond the Standard Model predicts the possible existence of new particles that can be searched at the low energy frontier in the sub-eV range. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles", such as axion or Axion-Like Particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of $2 \\times 14.3$ m. In 2014, this experiment has been run with an outstanding sensitivity, using an 18.5 W continuous wave laser emitting in the green spectral regime (532 nm). No regenerated photons have been detected after the wall, pushing the limits for the existence of axions and ALPs down to an unprecedented level for such a type of laboratory experiment. The di-photon couplings of possible pseudo-scalar and scalar ALPs can be constrained in the nearly massless limit to be less than $3.5\\cdot 10^{-8}$ GeV$^{-1}$ and $3.2\\cdot 10^{-8}$ GeV$^{-1}$, respectively.

  5. Reed-Joseph International Company

    E-Print Network [OSTI]

    is offering field downloadable GPS/VHF logging collars and Solar Powered GPS/VHF backpack loggers for birds of battery powered and solar powered PTTs in a wide range of sizes, exclusively for birds. We will startReed-Joseph International Company 55 YEARS OF EXCELLENCE IN BIRD AND WILDLIFE CONTROL THE U

  6. International energy annual 1997

    SciTech Connect (OSTI)

    NONE

    1999-04-01T23:59:59.000Z

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power and geothermal, solar, and wind electric power. Also included are biomass electric power for Brazil and the US, and biomass, geothermal, and solar energy produced in the US and not used for electricity generation. This report is published to keep the public and other interested parties fully informed of primary energy supplies on a global basis. The data presented have been largely derived from published sources. The data have been converted to units of measurement and thermal values (Appendices E and F) familiar to the American public. 93 tabs.

  7. International Energy Agency

    Broader source: Energy.gov [DOE]

    DOE's market transformation efforts have reached to European and other countries who are part of the international distributed and decentralized energy community. Through its partnership with DOE, the combined heat and power (CHP) program of the International Energy Agency (IEA) conducts research and analysis of CHP markets and deployment efforts around the world and has used lessons learned from U.S. research, development, and deployment efforts to recommend market transformation activities and policies that will lead to new CHP installations worldwide.

  8. Integrated CHP/Advanced Reciprocating Internal Combustion Engine...

    Broader source: Energy.gov (indexed) [DOE]

    restrictions. Integrated Combined Heat and PowerAdvanced Reciprocating Internal Combustion Engine System for Landfill Gas to Power Applications More Documents & Publications...

  9. August 24~28, 2014 International Convention Center (ICC) Jeju, Jeju Island, Korea

    E-Print Network [OSTI]

    Symposium on Future I&C for Nuclear Power Plants International Symposium on Symbiotic Nuclear Power Systems Plants International Symposium on Symbiotic Nuclear Power Systems ISOFIC/ISSNP 2014 #12;Foreword, Jeju Island, Korea International Symposium on Future I&C for Nuclear Power Plants International

  10. 337978-1-4577-1597-6/12/$26.00 2012 IEEE Proceedings of the 2012 24th International Symposium on Power Semiconductor Devices and ICs

    E-Print Network [OSTI]

    Ng, Wai Tung

    on Power Semiconductor Devices and ICs 3-7 June 2012 - Bruges, Belgium Fig.1 (a) Schematic cross-section of AlGaN/GaN HEMT with conventional field plate, where LFP is the field plate length. (b) with Novel Air-bridge bridge field plate distance, air bridge footprint width and gate­drain distance (drift region

  11. Conference 5739, SPIE International Symposium Integrated Optoelectronic Devices, 22-27 Jan 2005, San Jose, CA Development of high power green light emitting diode dies in

    E-Print Network [OSTI]

    Wetzel, Christian M.

    , San Jose, CA Development of high power green light emitting diode dies in piezoelectric Ga in green light emitting diodes is one of the big challenges towards all-solid- state lighting. The prime,3], and commercialization [4,5] of high brightness light emitting diodes LEDs has led to a 1.82 Billion-$/year world market

  12. IEEE International Conference on Power and Energy (PECon 08), December 1-3, 2008, Johor Bahru, Malaysia. Abstract--Electricity consumer dishonesty is a problem faced

    E-Print Network [OSTI]

    Ducatelle, Frederick

    , electricity theft, non-technical loss, load profile. I. INTRODUCTION LECTRIC utilities lose large amounts annual revenue [5], which is relatively low when compared to losses faced by electric utilities, Malaysia. Abstract--Electricity consumer dishonesty is a problem faced by all power utilities. Finding

  13. 8th International Conference on Probability Methods Applied to Power Systems, Ames Iowa, September 2004 Estimating Failure Propagation in Models of

    E-Print Network [OSTI]

    Reliability Technology Solutions and funding in part by the Assistant Secretary for Energy Efficiency Vickie E. Lynch Bertrand Nkei David E. Newman Abstract-- We compare and test statistical estimates and Renewable Energy, Office of Power Technologies, Transmission Reliability Program of the U.S. Department

  14. Proc. International Symposium on Circuits and Systems (ISCAS), vol. 5, pp 653 -656, Geneva (Switzerland), May 2000 Low Power/Low Voltage High Speed CMOS Differential

    E-Print Network [OSTI]

    Fayomi, Christian

    @vlsi.polymtl.ca ABSTRACT A new CMOS differential latched comparator suitable for low voltage, low-power application domains. At the same time, designing analog circuits that can operate from a low-voltage supply on a single ended design configuration. It consists of two operational transconductance amplifiers (NMOS

  15. International Conference on Renewable Energies and Power Quality 2009 (ICREPQ'08), Santander (Spain) 12-14 of March 2008 PWM CONTROL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of a stand-alone wind and photovoltaic system, associated with electrochemical energy storage [1, stand- alone system, energy modelling, PWM converter. 1. Introduction The sizing optimization with reactive power. Energy models are then inserted in a sizing optimization algorithm in order to minimize

  16. EIS-0032: 500 kV International Transmission Line NSP-TR-1, Forbes, Minnesota to Manitoba, Canada, Northern States Power Company

    Broader source: Energy.gov [DOE]

    The Economic Regulatory Administration developed this EIS to evaluate the environmental impacts of a 500-kilovolt transmission line proposed by the Northern States Power Company to provide a transmission facility for the exchange of electrical energy between Canada and the United States.

  17. Maxwell's field coupled nonminimally to quadratic torsion: Induced axion field and birefringence of the vacuum

    E-Print Network [OSTI]

    Yakov Itin; Friedrich W. Hehl

    2003-08-03T23:59:59.000Z

    We consider a possible (parity conserving) interaction between the electromagnetic field $F$ and a torsion field $T^\\alpha$ of spacetime. For generic elementary torsion, gauge invariant coupling terms of lowest order fall into two classes that are both nonminimal and {\\it quadratic} in torsion. These two classes are displayed explicitly. The first class of the type $\\sim F T^2$ yields (undesirable) modifications of the Maxwell equations. The second class of the type $\\sim F^2 T^2$ doesn't touch the Maxwell equations but rather modifies the constitutive tensor of spacetime. Such a modification can be completely described in the framework of metricfree electrodynamics. We recognize three physical effects generated by the torsion: (i) An axion field that induces an {\\em optical activity} into spacetime, (ii) a modification of the light cone structure that yields {\\em birefringence} of the vacuum, and (iii) a torsion dependence of the {\\em velocity of light.} We study these effects in the background of a Friedmann universe with torsion. {\\it File tor17.tex, 02 August 2003}

  18. CONSTRAINTS ON AXION-LIKE PARTICLES FROM X-RAY OBSERVATIONS OF THE HYDRA GALAXY CLUSTER

    SciTech Connect (OSTI)

    Wouters, Denis; Brun, Pierre, E-mail: denis.wouters@cea.fr, E-mail: pierre.brun@cea.fr [CEA, Irfu, Centre de Saclay, F-91191 Gif-sur-Yvette (France)

    2013-07-20T23:59:59.000Z

    Axion-like particles (ALPs) belong to a class of new pseudoscalar particles that generically couple to photons, opening the possibility of oscillations from photons into ALPs in an external magnetic field. Having witnessed the turbulence of their magnetic fields, these oscillations are expected to imprint irregularities on a limited energy range of the spectrum of astrophysical sources. In this study, Chandra observations of the Hydra galaxy cluster are used to constrain the value of the coupling of ALPs to photons. We consider the conversion of X-ray photons from the central source Hydra A in the magnetic field of the cluster. The magnetic field strength and structure are well determined observationally, which adds to the robustness of the analysis. The absence of anomalous irregularities in the X-ray spectrum of Hydra A conservatively provides the most competitive constraints on the coupling constant for ALP masses below 7 Multiplication-Sign 10{sup -12} eV at the level of g{sub {gamma}a} < 8.3 Multiplication-Sign 10{sup -12} GeV{sup -1} at the 95% confidence level. Because of the specific phenomenology involved, these constraints actually hold more generally for very light pseudo-Nambu-Goldstone bosons.

  19. Gravitational Lensing by Kerr-Sen Dilaton-Axion Black Hole in the Weak Deflection Limit

    SciTech Connect (OSTI)

    Gyulchev, G. N. [Department of Physics, Biophysics and Roentgenology, Faculty of Medicine, St. Kliment Ohridski, University of Sofia, 1 Kozyak str., 1407 Sofia (Bulgaria); Yazadjiev, S. S. [Department of Theoretical Physics, Faculty of Physics, St. Kliment Ohridski University of Sofia, 5 James Bourchier Blvd., 1164 Sofia (Bulgaria)

    2010-11-25T23:59:59.000Z

    We investigate analytically gravitational lensing by charged, stationary, axially symmetric Kerr-Sen dilaton-axion black hole in the weak deflection limit. Approximate solutions to the lightlike equations of motion are present up to and including third-order terms in M/b, a/b and r{sub {alpha}}/b, where M is the black hole mass, a is the angular momentum, r{sub {alpha}}= Q{sup 2}/M,Q being the charge and b is the impact parameter of the light ray. We compute the positions of the two weak field images up to post-Newtonian order. The shift of the critical curves as a function of the lens angular momentum is found, and it is shown that they decrease slightly with the increase of the charge. The lensing observables are compared to these characteristics for particular cases as Schwarzschild and Kerr black holes as well as the Gibbons-Maeda-Garfinkle-Horowitz-Strominger black hole.

  20. Self-powered microthermionic converter

    DOE Patents [OSTI]

    Marshall, Albert C.; King, Donald B.; Zavadil, Kevin R.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

    2004-08-10T23:59:59.000Z

    A self-powered microthermionic converter having an internal thermal power source integrated into the microthermionic converter. These converters can have high energy-conversion efficiencies over a range of operating temperatures. Microengineering techniques are used to manufacture the converter. The utilization of an internal thermal power source increases potential for mobility and incorporation into small devices. High energy efficiency is obtained by utilization of micron-scale interelectrode gap spacing. Alpha-particle emitting radioisotopes can be used for the internal thermal power source, such as curium and polonium isotopes.