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1

Gauging the cosmic microwave background  

E-Print Network (OSTI)

We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the effect of super-Hubble modes on the CMB. We calculate a transfer function that encodes the behaviour of the dipole, and examine its long-wavelength behaviour. We show that contributions to the dipole from adiabatic super-Hubble modes are strongly suppressed, even in the presence of a cosmological constant, contrary to claims in the literature. We also introduce a naturally defined CMB monopole, which exhibits closely analogous long-wavelength behaviour. We discuss the geometrical origin of this super-Hubble suppression, pointing out that it is a simple reflection of adiabaticity, and hence argue that it will occur regardless of the matter content.

J. P. Zibin; Douglas Scott

2008-12-21T23:59:59.000Z

2

The Cosmic Microwave Background and Particle Physics  

E-Print Network (OSTI)

In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our primary focus is on new CMB tests of inflation. We explain how the inflationary predictions for the geometry of the Universe and primordial density perturbations will be tested by CMB temperature fluctuations, and how the gravitational waves predicted by inflation can be pursued with the CMB polarization. The CMB signatures of topological defects and primordial magnetic fields from cosmological phase transitions are also discussed. Furthermore, we review current and future CMB constraints on various types of dark matter (e.g. massive neutrinos, weakly interacting massive particles, axions, vacuum energy), decaying particles, the baryon asymmetry of the Universe, ultra-high-energy cosmic rays, exotic cosmological topologies, and other new physics.

Marc Kamionkowski; Arthur Kosowsky

1999-04-09T23:59:59.000Z

3

Cosmic Microwave Background Tests of Inflation  

E-Print Network (OSTI)

Inflation provides a unified paradigm for understanding the isotropy of the cosmic microwave background (CMB), the flatness problem, and the origin of large-scale structure. Although the physics responsible for inflation is not yet well understood, slow-roll inflation generically makes several predictions: a flat Universe, primordial adiabatic density perturbations, and a stochastic gravity-wave background. Inflation further predicts specific relations between the amplitudes and shapes of the spectrum of density perturbations and gravity waves. There are now excellent prospects for testing precisely these predictions with forthcoming CMB temperature and polarization maps. Here I discuss these new CMB tests of inflation.

Marc Kamionkowski

1998-03-14T23:59:59.000Z

4

CMB  

NLE Websites -- All DOE Office Websites (Extended Search)

Hubble Diagram Hubble Diagram CMB BBN Cosmic Microwave Background One of the predictions that the Big Bang theory leads to, concerns some left over pieces that could tell us the temperature of the universe.. IF we believe that the Big Bang is how the universe began, then theorists predict that we should see a remnant microwave background. It is microwave because that is the area of the spectrum in which it is found. When we look out into space with our bare eyes, we see bright objects and a whole lot of "empty" space. However, if we examine the sky with a radio telescope, we see an almost perfect blackbody spectrum in the microwave spectrum. What is a blackbody and why is it radiating? How did we find the Cosmic Microwave Background? And can we fit a curve to the data taken for the Cosmic

5

Local microwave background radiation  

E-Print Network (OSTI)

An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

Domingos Soares

2014-11-13T23:59:59.000Z

6

Cosmic Microwave Background: Past, Future, and Present  

E-Print Network (OSTI)

I explain the origin and evolution of anisotropies in the Cosmic Microwave Background (CMB) and argue that upcoming experiments will measure cosmological and fundamental parameters very accurately. Most of the paper focuses on present data, which strongly suggest that the universe is flat. Several arguments are given to prove that present data sets are not contaminated by systematics. New techniques to compare different experiments visually are introduced. These are illustrated for two years of the MSAM and Python experiments.

Scott Dodelson

1999-12-22T23:59:59.000Z

7

The Cosmic Microwave Background: Beyond the Power Spectrum  

E-Print Network (OSTI)

Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However, there is more that can conceivably be done with CMB measurements. Here I briefly survey a few such ideas: cross-correlation with other cosmic backgrounds as a probe of the density of the Universe; CMB polarization as a gravitational-wave detector; secondary anisotropies and the ionization history of the Universe; tests of alternative-gravity theories; polarization, the Sunyaev-Zeldovich effect, and cosmic variance; and tests for a neutrino mass.

Marc Kamionkowski

1998-09-24T23:59:59.000Z

8

New physics from the Cosmic Microwave Background  

E-Print Network (OSTI)

I review the present status of the Cosmic Microwave Background, with some emphasis on the current and future implications for particle physics. Conclusions are: gravitational instability in a dark matter dominated universe grew today's structure; the Universe remained neutral until z<~50; the CMB power spectrum peaks at 150<~l<~350; the large-scale structure of spacetime appears to be simple; something like inflation is something like proven; we will learn a great deal about cosmology, astrophysics and particle physics from MAP and Planck.

Douglas Scott

1999-11-17T23:59:59.000Z

9

Determining cosmic microwave background anisotropies in the presence of foregrounds  

E-Print Network (OSTI)

Separating foregrounds from the signal is one of the big challenges in cosmic microwave background (CMB) experiments. A simple way to estimate the CMB temperature in a given pixel is to fit for the amplitudes of the CMB and the various foreground components. The variance squared of this estimator is shown to be equal to $[(FDF)^2\\ \\sigzt + \\sigsh^2]$, where $\\sigz$ is the variance in the absence of foregrounds; $\\sigsh$ is the variance due to the uncertainty in the shapes of the foreground components; and FDF is the {\\it foreground degradation factor}. This one number, the FDF, gives a good indication of the ability of a given experiment to disentangle the CMB from foreground sources. A variety of applications relating to the planning and analyzing of experiments is presented.

Scott Dodelson

1995-12-05T23:59:59.000Z

10

Anisotropies in the Cosmic Microwave Background: Theory  

E-Print Network (OSTI)

Anisotropies in the Cosmic Microwave Background (CMB) contain a wealth of information about the past history of the universe and the present values of cosmological parameters. I ouline some of the theoretical advances of the last few years. In particular, I emphasize that for a wide class of cosmological models, theorists can accurately calculate the spectrum to better than a percent. The specturm of anisotropies today is directly related to the pattern of inhomogeneities present at the time of recombination. This recognition leads to a powerful argument that will enable us to distinguish inflationary models from other models of structure formation. If the inflationary models turn out to be correct, the free parameters in these models will be determined to unprecedented accuracy by the upcoming satellite missions.

Scott Dodelson

1997-02-14T23:59:59.000Z

11

Non-thermal Cosmic Backgrounds from Blazars: the contribution to the CMB, X-ray and gamma-ray Backgrounds  

E-Print Network (OSTI)

We present a new assessment of the contribution of Blazars to the extragalactic background radiation across the e.m. spectrum. Our calculations rely on deep Blazar radio counts that we derived combining several multifrequency surveys. The integrated Blazar emission yields a broad-band non-thermal background that in some parts of the e.m. spectrum dominates the extragalactic brightness. Blazars are the main point-like contributors to the CMB. Their integrated emission causes an apparent T increase of 5-50 muK in the 50-250 GHz range. The CMB fluctuation spectrum is sensibly contaminated at l>300, for a Poissonian source distribution, or at lower l values if spatial clustering is present. We estimate that well over 100,000 Blazars will produce a significant signal in the PLANCK CMB anisotropy maps. Because of the microwave-Xray flux correlation, these sources are expected to have flux > a few 10^{-15} erg/s in the soft X-ray band. Thus, a large fraction of the foreground sources in CMB anisotropy maps could be ...

Giommi, P; Cavazzuti, E; Perri, M; Pittori, C

2006-01-01T23:59:59.000Z

12

Non-thermal Cosmic Backgrounds from Blazars: the contribution to the CMB, X-ray and gamma-ray Backgrounds  

E-Print Network (OSTI)

We present a new assessment of the contribution of Blazars to the extragalactic background radiation across the e.m. spectrum. Our calculations rely on deep Blazar radio counts that we derived combining several multifrequency surveys. The integrated Blazar emission yields a broad-band non-thermal background that in some parts of the e.m. spectrum dominates the extragalactic brightness. Blazars are the main point-like contributors to the CMB. Their integrated emission causes an apparent T increase of 5-50 muK in the 50-250 GHz range. The CMB fluctuation spectrum is sensibly contaminated at l>300, for a Poissonian source distribution, or at lower l values if spatial clustering is present. We estimate that well over 100,000 Blazars will produce a significant signal in the PLANCK CMB anisotropy maps. Because of the microwave-Xray flux correlation, these sources are expected to have flux > a few 10^{-15} erg/s in the soft X-ray band. Thus, a large fraction of the foreground sources in CMB anisotropy maps could be identified and removed using a multi frequency approach, provided that a sufficiently deep all sky X-ray survey will be available. We further show that Blazars are a major constituent of all high-E extragalactic backgrounds. Their contribution is 11-12% at X-ray frequencies and possibly 100% in the 0.5-50 MeV band. At E>100 MeV, the Blazar collective emission, obtained extrapolating their integrated micro-wave flux to the gamma-ray band using the SED of EGRET detected sources, over-predicts the extragalactic background by a large factor, implying that Blazars not only dominate the gamma-ray sky but also that their average duty cycle at these frequencies must be rather low. We also find that Blazars of the HBL type may produce a significant amount of flux at TeV energies.

P. Giommi; S. Colafrancesco; E. Cavazzuti; M. Perri; C. Pittori

2005-08-01T23:59:59.000Z

13

Weighing the Universe with the Cosmic Microwave Background  

E-Print Network (OSTI)

Variations in $\\Omega$, the total density of the Universe, leave a clear and distinctive imprint on the power spectrum of temperature fluctuations in the cosmic microwave background (CMB). This signature is virtually independent of other cosmological parameters or details of particular cosmological models. We evaluate the precision with which $\\Omega$ can be determined by a CMB map as a function of sky coverage, pixel noise, and beam size. For example, assuming only that the primordial density perturbations were adiabatic and with no prior information on the values of any other cosmological parameters, a full-sky CMB map at $0.5^\\circ$ angular resolution and a noise level of $15\\,\\mu{\\rm K}$ per pixel can determine $\\Omega$ with a variance of 5\\%. If all other cosmological parameters are fixed, $\\Omega$ can be measured to better than 1\\%.

Gerard Jungman; Marc Kamionkowski; Arthur Kosowsky; David N. Spergel

1995-07-21T23:59:59.000Z

14

Cosmological-Parameter Determination with Microwave Background Maps  

E-Print Network (OSTI)

The angular power spectrum of the cosmic microwave background (CMB) contains information on virtually all cosmological parameters of interest, including the geometry of the Universe ($\\Omega$), the baryon density, the Hubble constant ($h$), the cosmological constant ($\\Lambda$), the number of light neutrinos, the ionization history, and the amplitudes and spectral indices of the primordial scalar and tensor perturbation spectra. We review the imprint of each parameter on the CMB. Assuming only that the primordial perturbations were adiabatic, we use a covariance-matrix approach to estimate the precision with which these parameters can be determined by a CMB temperature map as a function of the fraction of sky mapped, the level of pixel noise, and the angular resolution. For example, with no prior information about any of the cosmological parameters, a full-sky CMB map with $0.5^\\circ$ angular resolution and a noise level of 15 $\\mu$K per pixel can determine $\\Omega$, $h$, and $\\Lambda$ with standard errors of $\\pm0.1$ or better, and provide determinations of other parameters which are inaccessible with traditional observations. Smaller beam sizes or prior information on some of the other parameters from other observations improves the sensitivity. The dependence on the the underlying cosmological model is discussed.

Gerard Jungman; Marc Kamionkowski; Arthur Kosowsky; David N. Spergel

1996-05-23T23:59:59.000Z

15

Measurement of a Peak in the Cosmic Microwave Background Power  

Science Journals Connector (OSTI)

We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 03 to 5° from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system in 1997, we mapped more than 200 deg2 at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26' and 165 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1° with an amplitude 70 ?KCMB.

P. D. Mauskopf; P. A. R. Ade; P. de Bernardis; J. J. Bock; J. Borrill; A. Boscaleri; B. P. Crill; G. DeGasperis; G. De Troia; P. Farese; P. G. Ferreira; K. Ganga; M. Giacometti; S. Hanany; V. V. Hristov; A. Iacoangeli; A. H. Jaffe; A. E. Lange; A. T. Lee; S. Masi; A. Melchiorri; F. Melchiorri; L. Miglio; T. Montroy; C. B. Netterfield; E. Pascale; F. Piacentini; P. L. Richards; G. Romeo; J. E. Ruhl; E. Scannapieco; F. Scaramuzzi; R. Stompor; N. Vittorio

2000-01-01T23:59:59.000Z

16

Differential Microwave Radiometer and the Cosmic Microwave Background |  

Office of Science (SC) Website

Differential Differential Microwave Radiometer and the Cosmic Microwave Background Laboratory Policy and Evaluation (LPE) LPE Home Staff M&O Contracts SC Laboratory Appraisal Process Laboratory Planning Process Work for Others in the Office of Science Laboratory Directed Research and Development (LDRD) DOE's Philosophy on LDRD Frequently Asked Questions Success Stories Brochures Additional Information LDRD Program Contacts Technology Transfer DOE National Laboratories Contact Information Laboratory Policy and Evaluation U.S. Department of Energy SC-32/Forrestal Building 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5447 F: (202) 586-3119 Success Stories Differential Microwave Radiometer and the Cosmic Microwave Background Print Text Size: A A A RSS Feeds FeedbackShare Page

17

Testing gaussianity, homogeneity and isotropy with the cosmic microwave background  

E-Print Network (OSTI)

We review the basic hypotheses which motivate the statistical framework used to analyze the cosmic microwave background, and how that framework can be enlarged as we relax those hypotheses. In particular, we try to separate as much as possible the questions of gaussianity, homogeneity and isotropy from each other. We focus both on isotropic estimators of non-gaussianity as well as statistically anisotropic estimators of gaussianity, giving particular emphasis on their signatures and the enhanced "cosmic variances" that become increasingly important as our putative Universe becomes less symmetric. After reviewing the formalism behind some simple model-independent tests, we discuss how these tests can be applied to CMB data when searching for large scale "anomalies"

L. Raul Abramo; Thiago S. Pereira

2010-05-13T23:59:59.000Z

18

Cosmic Microwave Background Mini-Review  

E-Print Network (OSTI)

A compact overview of the status of CMB anisotropy results and their cosmological interpretation up until the end of 2005. Sections headings: Introduction; Description of CMB Anisotropies; Cosmological Parameters; Physics of Anisotropies; Current Anisotropy Data; CMB Polarization; Complications; Constraints on Cosmologies; Particle Physics Constraints; Fundamental Lessons; and Future Directions.

Douglas Scott; George Smoot

2006-01-14T23:59:59.000Z

19

ON THE EFFECT OF THE COSMIC MICROWAVE BACKGROUND IN HIGH-REDSHIFT (SUB-)MILLIMETER OBSERVATIONS  

SciTech Connect

Modern (sub-)millimeter interferometers enable the measurement of the cool gas and dust emission of high-redshift galaxies (z > 5). However, at these redshifts the cosmic microwave background (CMB) temperature is higher, approaching, and even exceeding, the temperature of cold dust and molecular gas observed in the local universe. In this paper, we discuss the impact of the warmer CMB on (sub-)millimeter observations of high-redshift galaxies. The CMB affects the observed (sub-)millimeter dust continuum and the line emission (e.g., carbon monoxide, CO) in two ways: (1) it provides an additional source of (both dust and gas) heating and (2) it is a non-negligible background against which the line and continuum emission are measured. We show that these two competing processes affect the way we interpret the dust and gas properties of high-redshift galaxies using spectral energy distribution models. We quantify these effects and provide correction factors to compute what fraction of the intrinsic dust (and line) emission can be detected against the CMB as a function of frequency, redshift, and temperature. We discuss implications on the derived properties of high-redshift galaxies from (sub-)millimeter data. Specifically, the inferred dust and molecular gas masses can be severely underestimated for cold systems if the impact of the CMB is not properly taken into account.

Da Cunha, Elisabete; Groves, Brent; Walter, Fabian; Decarli, Roberto; Rix, Hans-Walter [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)] [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Weiss, Axel [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)] [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Bertoldi, Frank [Argelander Institute for Astronomy, University of Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany)] [Argelander Institute for Astronomy, University of Bonn, Auf dem Huegel 71, D-53121 Bonn (Germany); Carilli, Chris [National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States)] [National Radio Astronomy Observatory, Pete V. Domenici Array Science Center, P.O. Box O, Socorro, NM 87801 (United States); Daddi, Emanuele; Sargent, Mark [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d'Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France)] [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d'Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Elbaz, David; Ivison, Rob [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)] [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Maiolino, Roberto [Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE (United Kingdom)] [Cavendish Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Riechers, Dominik [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)] [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Smail, Ian, E-mail: cunha@mpia.de [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom)] [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom)

2013-03-20T23:59:59.000Z

20

Possible Relics from New Physics in the Early Universe: Inflation, the Cosmic Microwave Background, and Particle Dark Matter  

E-Print Network (OSTI)

I review two different connections between particle theory and early-Universe cosmology: (1) Cosmic-microwave-background (CMB) tests of inflation and (2) particle dark matter. The inflationary predictions of a flat Universe and a nearly scale-invariant spectrum of primordial density perturbations will be tested precisely with forthcoming maps of the CMB temperature. A stochastic gravitational-wave background may be probed with a map of the CMB polarization. I also discuss some other uses of CMB maps. Particle theory has produced two very well-motivated candidates for the dark matter in the Universe: an axion and a supersymmetric particle. In both cases, there are a variety of experiments afoot to detect these particles. I review the properties of these dark-matter candidates and these detection techniques. Much of the material here has appeared before in astro-ph/9712215 and hep-ph/9710467, but the article here is updated and also expanded considerably.

Marc Kamionkowski

1998-09-16T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

The Distortion of the Cosmic Microwave Background by the Milky Way  

E-Print Network (OSTI)

The Milky Way can act as a large-scale weak gravitational lens of the cosmic microwave background (CMB). We study this effect using a photon ray-tracing code and a Galactic mass distribution with disk, bulge and halo components. For an observer at the Sun's coordinates in the Galaxy, the bending of CMB photon paths is limited to less than one arcsecond, and only for rays that pass within a few degrees of the Galactic Center. However, the entire sky is affected, resulting in global distortions of the CMB on large angular scales. These distortions can cause the low-order multipoles of a spherical harmonic expansion of the CMB sky temperature to leak into higher-order modes. Thus the component of the CMB dipole that results from the Local Group's motion relative to the local cosmic frame of rest contributes to higher-order moments for an observer in the solar system. With our ray-tracing code we show that the phenomenon is not sensitive to the specific choice of Galactic potential. We also quantitatively rule it...

Czaja, Benjamin

2014-01-01T23:59:59.000Z

22

On the ultra high energy cosmic rays and the origin of the cosmic microwave background radiation  

E-Print Network (OSTI)

Some inconsistencies to the assumption of a cosmological origin of the cosmic microwave background CMB, such as the absence of gravitational lensing in the WMAP data, open the doors to some speculations such as a local origin to the CMB. We argue here that this assumption agrees with the absence of the GZK cutoff (at least according to AGASA data) in the energy spectrum of the cosmic ray due to the cosmic interaction with the CMB at $6\\times 10^{19} eV$ or above. Within 50 Mpc from Earth, the matter and light distributions are close to an anisotropic distribution, where the local cluster and local super-clusters of galaxies can be identified. In contrast, the ultra high energy comic rays data is consistent to an almost isotropic distribution, and there is no correlation between their arrival direction and astronomical sources within our local cluster. This means that the events above the GZK cutoff come from distances above 50 Mpc, without an apparent energy loss. This scenario is plausible under the assumption of the CMB concentrated only within 3-4 Mpc from Earth. In other words, the CMB has a local origin linked only to the local super-cluster of galaxies. In addition, the galactic and extragalactic energy spectra index within the energy equipartition theorem strongly constrains the dark matter and dark energy hypothesis, essential in the Big Bang cosmology.

C. E. Navia; C. R. A. Augusto; K. H. Tsui

2007-07-12T23:59:59.000Z

23

Effect of a chameleon scalar field on the cosmic microwave background  

Science Journals Connector (OSTI)

We show that a direct coupling between a chameleonlike scalar field and photons can give rise to a modified Sunyaev-Zel’dovich (SZ) effect in the cosmic microwave background (CMB). The coupling induces a mixing between chameleon particles and the CMB photons when they pass through the magnetic field of a galaxy cluster. Both the intensity and the polarization of the radiation are modified. The degree of modification depends strongly on the properties of the galaxy cluster such as magnetic field strength and electron number density. Existing SZ measurements of the Coma cluster enable us to place constraints on the photon-chameleon coupling. The constrained conversion probability in the cluster is PComa(204??GHz)<6.2×10-5 at 95% confidence, corresponding to an upper bound on the coupling strength of geff(cell)<2.2×10-8??GeV-1 or geff(Kolmo)<(7.2–32.5)×10-10??GeV-1, depending on the model that is assumed for the cluster magnetic field structure. We predict the radial profile of the chameleonic CMB intensity decrement. We find that the chameleon effect extends farther toward the edges of the cluster than the thermal SZ effect. Thus we might see a discrepancy between the x-ray emission data and the observed SZ intensity decrement. We further predict the expected change to the CMB polarization arising from the existence of a chameleonlike scalar field. These predictions could be verified or constrained by future CMB experiments.

Anne-Christine Davis; Camilla A. O. Schelpe; Douglas J. Shaw

2009-09-10T23:59:59.000Z

24

Information Gains from Cosmic Microwave Background Experiments  

E-Print Network (OSTI)

To shed light on the fundamental problems posed by Dark Energy and Dark Matter, a large number of experiments have been performed and combined to constrain cosmological models. We propose a novel way of quantifying the information gained by updates on the parameter constraints from a series of experiments which can either complement earlier measurements or replace them. For this purpose, we use the Kullback-Leibler divergence or relative entropy from information theory to measure differences in the posterior distributions in model parameter space from a pair of experiments. We apply this formalism to a historical series of Cosmic Microwave Background experiments ranging from Boomerang to WMAP, SPT, and Planck. Considering different combinations of these experiments, we thus estimate the information gain in units of bits and distinguish contributions from the reduction of statistical errors and the `surprise' corresponding to a significant shift of the parameters' central values. For this experiment series, we...

Seehars, Sebastian; Refregier, Alexandre; Paranjape, Aseem; Akeret, Joël

2014-01-01T23:59:59.000Z

25

A Fast Gridded Method for the Estimation of the Power Spectrum of the CMB from Interferometer Data with Application to the Cosmic Background Imager  

E-Print Network (OSTI)

We describe an algorithm for the extraction of the angular power spectrum of an intensity field, such as the cosmic microwave background (CMB), from interferometer data. This new method, based on the gridding of interferometer visibilities in the aperture plane followed by a maximum likelihood solution for bandpowers, is much faster than direct likelihood analysis of the visibilities, and deals with foreground radio sources, multiple pointings, and differencing. The gridded aperture-plane estimators are also used to construct Wiener-filtered images using the signal and noise covariance matrices used in the likelihood analysis. Results are shown for simulated data. The method has been used to determine the power spectrum of the cosmic microwave background from observations with the Cosmic Background Imager, and the results are given in companion papers.

S. T. Myers; C. R. Contaldi; J. R. Bond; U. -L. Pen; D. Pogosyan; S. Prunet; J. L. Sievers; B. S. Mason; T. J. Pearson; A. C. S. Readhead; M. C. Shepherd

2002-05-23T23:59:59.000Z

26

BAYESIAN INFERENCE OF POLARIZED COSMIC MICROWAVE BACKGROUND POWER SPECTRA FROM INTERFEROMETRIC DATA  

SciTech Connect

Detection of B-mode polarization of the cosmic microwave background (CMB) radiation is one of the frontiers of observational cosmology. Because they are an order of magnitude fainter than E-modes, it is quite a challenge to detect B-modes. Having more manageable systematics, interferometers prove to have a substantial advantage over imagers in detecting such faint signals. Here, we present a method for Bayesian inference of power spectra and signal reconstruction from interferometric data of the CMB polarization signal by using the technique of Gibbs sampling. We demonstrate the validity of the method in the flat-sky approximation for a simulation of an interferometric observation on a finite patch with incomplete uv-plane coverage, a finite beam size, and a realistic noise model. With a computational complexity of O(n {sup 3/2}), n being the data size, Gibbs sampling provides an efficient method for analyzing upcoming cosmology observations.

Karakci, Ata; Korotkov, Andrei; Tucker, Gregory S. [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912 (United States); Sutter, P. M.; Wandelt, Benjamin D. [Department of Physics, 1110 W. Green Street, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Zhang, Le; Timbie, Peter [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Bunn, Emory F., E-mail: ata_karakci@brown.edu [Physics Department, University of Richmond, Richmond, VA 23173 (United States)

2013-01-15T23:59:59.000Z

27

Statistics of Cosmic Microwave Background Polarization  

E-Print Network (OSTI)

We present a formalism for analyzing a full-sky temperature and polarization map of the cosmic microwave background. Temperature maps are analyzed by expanding over the set of spherical harmonics to give multipole moments of the two-point correlation function. Polarization, which is described by a second-rank tensor, can be treated analogously by expanding in the appropriate tensor spherical harmonics. We provide expressions for the complete set of temperature and polarization multipole moments for scalar and tensor metric perturbations. Four sets of multipole moments completely describe isotropic temperature and polarization correlations; for scalar metric perturbations one set is identically zero, giving the possibility of a clean determination of the vector and tensor contributions. The variance with which the multipole moments can be measured in idealized experiments is evaluated, including the effects of detector noise, sky coverage, and beam width. Finally, we construct coordinate-independent polarization two-point correlation functions, express them in terms of the multipole moments, and derive small-angle limits.

Marc Kamionkowski; Arthur Kosowsky; Albert Stebbins

1996-11-15T23:59:59.000Z

28

BOOMERANG: A Balloon-borne Millimeter Wave Telescope and Total Power Receiver for Mapping Anisotropy in the Cosmic Microwave Background  

E-Print Network (OSTI)

We describe BOOMERANG; a balloon-borne microwave telescope designed to map the Cosmic Microwave Background (CMB) at a resolution of 10' from the Long Duration Balloon (LDB) platform. The millimeter-wave receiver employs new technology in bolometers, readout electronics, cold re-imaging optics, millimeter-wave filters, and cryogenics to obtain high sensitivity to CMB anisotropy. Sixteen detectors observe in 4 spectral bands centered at 90, 150, 240 and 410 GHz. The wide frequency coverage, the long duration flight, the optical design and the observing strategy provide strong rejection of systematic effects. We report the flight performance of the instrument during a 10.5 day stratospheric balloon flight launched from McMurdo Station, Antarctica that mapped ~2000 square degrees of the sky.

B. P. Crill; P. A. R. Ade; D. R. Artusa; R. S. Bhatia; J. J. Bock; A. Boscaleri; P. Cardoni; S. E. Church; K. Coble; P. deBernardis; G. deTroia; P. Farese; K. M. Ganga; M. Giacometti; C. V. Haynes; E. Hivon; V. V. Hristov; A. Iacoangeli; W. C. Jones; A. E. Lange; L. Martinis; S. Masi; P. V. Mason; P. D. Mauskopf; L. Miglio; T. Montroy; C. B. Netterfield; C. G. Paine; E. Pascale; F. Piacentini; G. Polenta; F. Pongetti; G. Romeo; J. E. Ruhl; F. Scaramuzzi; D. Sforna; A. D. Turner

2002-06-14T23:59:59.000Z

29

DASI First Results: A Measurement of the Cosmic Microwave Background Angular Power Spectrum  

E-Print Network (OSTI)

We present measurements of anisotropy in the Cosmic Microwave Background (CMB) from the first season of observations with the Degree Angular Scale Interferometer (DASI). The instrument was deployed at the South Pole in the austral summer 1999--2000, and made observations throughout the following austral winter. We have measured the angular power spectrum of the CMB in the range 100CMB. We detect a first peak in the power spectrum at l approx 200, in agreement with previous experiments. In addition, we detect a peak in the power spectrum at l approx 550 and power of similar magnitude at l approx 800 which are consistent with the second and third harmonic peaks predicted by adiabatic inflationary cosmological models.

N. W. Halverson; E. M. Leitch; C. Pryke; J. Kovac; J. E. Carlstrom; W. L. Holzapfel; M. Dragovan; J. K. Cartwright; B. S. Mason; S. Padin; T. J. Pearson; M. C. Shepherd; A. C. S. Readhead

2001-04-30T23:59:59.000Z

30

Measurements of the cosmic microwave background temperature at 1. 47 GHz  

SciTech Connect

A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 {plus minus} 0.25 K (68% C.L.) measured from White Mountain and 2.26 {plus minus} 0.21 K from the South Pole site. The combined result is 2.27 {plus minus} 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is {approximately}2.5 {sigma} ({approximately}l% probability) from the 2.74 {plus minus} 0.02,K global average CMB temperature.

Bensadoun, M.J.

1991-11-01T23:59:59.000Z

31

Measurements of the cosmic microwave background temperature at 1.47 GHz  

SciTech Connect

A radiofrequency-gain total power radiometer measured the intensity of the cosmic microwave background (CMB) at a frequency of 1.47 GHz (20.4 cm wavelength) from White Mountain, California, in September 1988 and from the South Pole, Antarctica, in December 1989. The CMB thermodynamic temperature, TCMB, is 2.27 {plus_minus} 0.25 K (68% C.L.) measured from White Mountain and 2.26 {plus_minus} 0.21 K from the South Pole site. The combined result is 2.27 {plus_minus} 0.19 K. The correction for galactic emission has been derived from scaled low-frequency maps and constitutes the main source, of error. The atmospheric signal is found by extrapolation from zenith scan measurements at higher frequencies. The result is consistent with previous low-frequency measurements, including a measurement at 1.41 GHz (Levin et al. 1988) made with an earlier version of this instrument. The result is {approximately}2.5 {sigma} ({approximately}l% probability) from the 2.74 {plus_minus} 0.02,K global average CMB temperature.

Bensadoun, M.J.

1991-11-01T23:59:59.000Z

32

Cosmic Microwave Background Temperature and Polarization Anisotropy in Brans-Dicke Cosmology  

E-Print Network (OSTI)

We develop a formalism for calculating cosmic microwave background (CMB) temperature and polarization anisotropies in cosmological models with Brans-Dicke gravity. We then modify publicly available Boltzmann codes to calculate numerically the temperature and polarization power spectra. Results are illustrated with a few representative models. Comparing with the general-relativistic model with the same cosmological parameters, both the amplitude and the width of the acoustic peaks are different in the Brans-Dicke models. We use a covariance-matrix calculation to investigate whether the effects of Brans-Dicke gravity are degenerate with those of variation in other cosmological parameters and to simultaneously determine whether forthcoming CMB maps might be able to distinguish Brans-Dicke and general-relativistic cosmology. Although the predicted power spectra for plausible Brans-Dicke models differ from those in general relativity only slightly, we find that MAP and/or the Planck Surveyor may in principle provide a test of Brans-Dicke theory that is competitive to solar-system tests. For example, if all other parameters except for the CMB normalization are fixed, a value of the Brans-Dicke parameter omega as large as 500 could be identified with MAP, and for Planck, values as large as omega \\simeq3000 could be identified; these sensitivities are decreased roughly by a factor of 3 if we marginalize over the baryon density, Hubble constant, spectral index, and reionization optical depth. In more general scalar-tensor theories, omega may evolve with time, and in this case, the CMB probe would be complementary to that from solar-system tests.

Xuelei Chen; Marc Kamionkowski

1999-05-27T23:59:59.000Z

33

CMB-Cluster Lensing  

E-Print Network (OSTI)

Clusters of galaxies are powerful cosmological probes, particularly if their masses can be determined. One possibility for mass determination is to study the cosmic microwave background (CMB) on small angular scales and observe deviations from a pure gradient due to lensing of massive clusters. I show that, neglecting contamination, this technique has the power to determine cluster masses very accurately, in agreement with estimates by Seljak and Zaldarriaga (1999). However, the intrinsic small scale structure of the CMB significantly degrades this power. The resulting mass constraints are useless unless one imposes a prior on the concentration parameter c. With even a modest prior on c, an ambitious CMB experiment (0.5' resolution and 1 microK per pixel) could determine masses of high redshift (z>0.5) clusters with ~ 30% accuracy.

Scott Dodelson

2004-02-12T23:59:59.000Z

34

Polarization of the Atmosphere as a Foreground for Cosmic Microwave Background Polarization Experiments  

E-Print Network (OSTI)

We quantify the level of polarization of the atmosphere due to Zeeman splitting of oxygen in the Earth's magnetic field and compare it to the level of polarization expected from the polarization of the cosmic microwave background radiation. The analysis focuses on the effect at mid-latitudes and at large angular scales. We find that from stratospheric balloon borne platforms and for observations near 100 GHz the atmospheric linear and circular polarized intensities is about 10^{-12} and 100 x 10^{-9} K, respectively, making the atmosphere a negligible source of foreground. From the ground the linear and circular polarized intensities are about 10^{-9} and 100 x 10^{-6} K, making the atmosphere a potential source of foreground for the CMB E (B) mode signal if there is even a 1% (0.01%) conversion of circular to linear polarization in the instrument.

Shaul Hanany; Philip Rosenkranz

2003-07-02T23:59:59.000Z

35

The effect of aberration on partial-sky measurements of the cosmic microwave background temperature power spectrum  

E-Print Network (OSTI)

Our motion relative to the cosmic-microwave-background (CMB) rest frame deflects light rays giving rise to shifts as large as L -> L(1+-beta), where beta=0.00123 is our velocity (in units of the speed of light) on measurements of small-scale (large multipole moment L) CMB fluctuations. For measurements at L>1000, where the CMB power spectrum varies roughly as C(L) ~ L^-7, the fractional change to the power spectrum measured on a small sky patch can be as large as Delta C(L)/C(L)~7*beta~1%, larger than the measurement uncertainties in several current experiments. Here we present a novel harmonic-space approach to this CMB aberration that improves upon prior work by allowing us to (i) go to higher orders in beta, thus extending the validity of the analysis to measurements at L>1/beta~800; and (ii) treat the effects of window functions and pixelization in a more accurate and computationally efficient manner. We calculate precisely the magnitude of the systematic bias in the power spectrum inferred from current S...

Jeong, Donghui; Dai, Liang; Kamionkowski, Marc; Wang, Xin

2014-01-01T23:59:59.000Z

36

New Constraints on Cosmic Polarization Rotation from B-Mode Polarization in Cosmic Microwave Background  

E-Print Network (OSTI)

STPpol, POLARBEAR and BICEP2 have recently measured the cosmic microwave background (CMB) B-mode polarization in various sky regions of several tens of square degrees and obtained BB power spectra in the multipole range 20-3000, detecting the components due to gravitational lensing and to inflationary gravitational waves. We analyze jointly the results of these three experiments and propose modifications of their analysis of the spectra to include in the model, in addition to the gravitational lensing and the inflationary gravitational waves components, also the effects induced by the cosmic polarization rotation (CPR), if it exists within current upper limits. Although in principle our analysis would lead also to new constraints on CPR, in practice these can only be given on its fluctuations , since constraints on its mean angle are inhibited by the de-rotation which is applied by current CMB polarization experiments, in order to cope with the insufficient calibration of the polarization angle. The combined data fits from all three experiments (with 29% CPR-SPTpol correlation, depending on theoretical model) gives constraint ^1/2 areas observed by SPTpol, POLARBEAR and BICEP2.

Sperello di Serego Alighieri; Wei-Tou Ni; Wei-Ping Pan

2014-04-07T23:59:59.000Z

37

Constraints on primordial magnetic fields from the optical depth of the cosmic microwave background  

E-Print Network (OSTI)

Damping of magnetic fields via ambipolar diffusion and decay of magnetohydrodynamical (MHD) turbulence in the post decoupling era heats the intergalactic medium (IGM). Collisional ionization weakly ionizes the IGM, producing an optical depth to scattering of the cosmic microwave background (CMB). The optical depth generated at $z\\gg 10$ does not affect the "reionization bump" of the CMB polarization power spectrum at low multipoles, but affects the temperature and polarization power spectra at high multipoles. Using the Planck 2013 temperature and lensing data together with the WMAP 9-year polarization data, we constrain the present-day field strength, $B_0$, smoothed over the damping length at the decoupling epoch as a function of the spectral index, $n_B$. We find the 95% upper bounds of $B_0<0.56$, 0.31, and 0.14 nG for $n_B=-2.9$, $-2.5$, and $-1.5$, respectively. For these spectral indices, the optical depth is dominated by dissipation of the decaying MHD turbulence that occurs shortly after the decou...

Kunze, Kerstin E

2015-01-01T23:59:59.000Z

38

REIONIZATION ON LARGE SCALES. II. DETECTING PATCHY REIONIZATION THROUGH CROSS-CORRELATION OF THE COSMIC MICROWAVE BACKGROUND  

SciTech Connect

We investigate the effect of patchy reionization on the cosmic microwave background (CMB) temperature. An anisotropic optical depth ?( n-hat ) alters the TT power spectrum on small scales l > 2000. We make use of the correlation between the matter density and the reionization redshift fields to construct full sky maps of ?( n-hat ). Patchy reionization transfers CMB power from large scales to small scales, resulting in a non-zero cross correlation between large and small angular scales. We show that the patchy ? correlator is sensitive to small root mean square (rms) values ?{sub rms} ? 0.003 seen in our maps. We include frequency-independent secondaries such as CMB lensing and kinetic Sunyaev-Zel'dovich (kSZ) terms, and show that patchy ? may still be detected at high significance. Reionization models that predict different values of ?{sub rms} may be distinguished even for the same mean value (?). It is more difficult to detect patchy ? in the presence of larger secondaries such as the thermal Sunyaev-Zel'dovich, radio background, and the cosmic infrared background. In this case, we show that patchy ? may be detected if these frequency-dependent secondaries are minimized to ?< 5 ?K (rms) by means of a multi-frequency analysis. We show that the patchy ? correlator provides information that is complementary to what may be obtained from the polarization and the kSZ power spectra.

Natarajan, A.; Battaglia, N.; Trac, H. [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Pen, U.-L. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Loeb, A. [Institute for Theory and Computation, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-10-20T23:59:59.000Z

39

SYSTEMATIC EFFECTS IN INTERFEROMETRIC OBSERVATIONS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION  

SciTech Connect

The detection of the primordial B-mode spectrum of the polarized cosmic microwave background (CMB) signal may provide a probe of inflation. However, observation of such a faint signal requires excellent control of systematic errors. Interferometry proves to be a promising approach for overcoming such a challenge. In this paper we present a complete simulation pipeline of interferometric observations of CMB polarization, including systematic errors. We employ two different methods for obtaining the power spectra from mock data produced by simulated observations: the maximum likelihood method and the method of Gibbs sampling. We show that the results from both methods are consistent with each other as well as, within a factor of six, with analytical estimates. Several categories of systematic errors are considered: instrumental errors, consisting of antenna gain and antenna coupling errors; and beam errors, consisting of antenna pointing errors, beam cross-polarization, and beam shape (and size) errors. In order to recover the tensor-to-scalar ratio, r, within a 10% tolerance level, which ensures the experiment is sensitive enough to detect the B-signal at r = 0.01 in the multipole range 28 < l < 384, we find that, for a QUBIC-like experiment, Gaussian-distributed systematic errors must be controlled with precisions of |g{sub rms}| = 0.1 for antenna gain, |{epsilon}{sub rms}| = 5 Multiplication-Sign 10{sup -4} for antenna coupling, {delta}{sub rms} Almost-Equal-To 0. Degree-Sign 7 for pointing, {zeta}{sub rms} Almost-Equal-To 0. Degree-Sign 7 for beam shape, and {mu}{sub rms} = 5 Multiplication-Sign 10{sup -4} for beam cross-polarization. Although the combined systematic effects produce a tolerance level on r twice as large for an experiment with linear polarizers, the resulting bias in r for a circular experiment is 15% which is still on the level of desirable sensitivity.

Karakci, Ata; Korotkov, Andrei; Tucker, Gregory S. [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912 (United States); Zhang Le; Timbie, Peter [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Sutter, P. M.; Wandelt, Benjamin D. [Department of Physics, 1110 W. Green Street, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Bunn, Emory F., E-mail: ata_karakci@brown.edu [Physics Department, University of Richmond, Richmond, VA 23173 (United States)

2013-07-15T23:59:59.000Z

40

Translational invariance and the anisotropy of the cosmic microwave background  

SciTech Connect

Primordial quantum fluctuations produced by inflation are conventionally assumed to be statistically homogeneous, a consequence of translational invariance. In this paper we quantify the potentially observable effects of a small violation of translational invariance during inflation, as characterized by the presence of a preferred point, line, or plane. We explore the imprint such a violation would leave on the cosmic microwave background anisotropy, and provide explicit formulas for the expected amplitudes of the spherical-harmonic coefficients.

Carroll, Sean M.; Tseng, C.-Y.; Wise, Mark B. [California Institute of Technology, Pasadena, California 91125 (United States)

2010-04-15T23:59:59.000Z

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41

On the radiative and thermodynamic properties of the Cosmic Microwave Background radiation using COBE FIRAS instrument data  

E-Print Network (OSTI)

Use formulas to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, pressure, enthalpy density, and internal energy density in the finite range of frequencies are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.728 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant are calculated. In the case of the dipole spectrum, the constants a and the Stefan-Bol...

Fisenko, Anatoliy I

2014-01-01T23:59:59.000Z

42

CMB Anisotropies from Outflows in Lyman Break Galaxies  

E-Print Network (OSTI)

Thomson scattering of the Cosmic Microwave Background (CMB) on moving electrons in the outflows of Lyman Break Galaxies (LBGs) at redshifts 2-8 contributes to the small-scale CMB anisotropies. The net effect produced by each outflow depends on its level of deviation from spherical symmetry, caused either by an anisotropic energy injection from the nuclear starburst or quasar activity, or by an inhomogeneous intergalactic environment. We find that for plausible outflow parameters consistent with spectroscopic observations of LBGs, the induced CMB anisotropies on arcminute scales reach up to $\\sim 1 \\mu$K, comparable to the level produced during the epoch of reionization.

Daniel Babich; Abraham Loeb

2006-09-14T23:59:59.000Z

43

COSMIC MICROWAVE BACKGROUND POLARIZATION AND TEMPERATURE POWER SPECTRA ESTIMATION USING LINEAR COMBINATION OF WMAP 5 YEAR MAPS  

SciTech Connect

We estimate cosmic microwave background (CMB) polarization and temperature power spectra using Wilkinson Microwave Anisotropy Probe (WMAP) 5 year foreground contaminated maps. The power spectrum is estimated by using a model-independent method, which does not utilize directly the diffuse foreground templates nor the detector noise model. The method essentially consists of two steps: (1) removal of diffuse foregrounds contamination by making linear combination of individual maps in harmonic space and (2) cross-correlation of foreground cleaned maps to minimize detector noise bias. For the temperature power spectrum we also estimate and subtract residual unresolved point source contamination in the cross-power spectrum using the point source model provided by the WMAP science team. Our TT, TE, and EE power spectra are in good agreement with the published results of the WMAP science team. We perform detailed numerical simulations to test for bias in our procedure. We find that the bias is small in almost all cases. A negative bias at low l in TT power spectrum has been pointed out in an earlier publication. We find that the bias-corrected quadrupole power (l(l + 1)C{sub l} /2{pi}) is 532 {mu}K{sup 2}, approximately 2.5 times the estimate (213.4 {mu}K{sup 2}) made by the WMAP team.

Samal, Pramoda Kumar; Jain, Pankaj [Department of Physics, Indian Institute of Technology, Kanpur (India); Saha, Rajib [Jet Propulsion Laboratory, M/S 169-327, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Delabrouille, Jacques [CNRS, Laboratoire APC, 10, rue Alice Domon et Leonie Duquet, 75205 Paris (France); Prunet, Simon [Institut d'Astrophysique de Paris, 98 bis Boulevard Arago, F-75014 Paris (France); Souradeep, Tarun [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India)

2010-05-01T23:59:59.000Z

44

Constraints on holographic dark energy from the latest supernovae, galaxy clustering, and cosmic microwave background anisotropy observations  

Science Journals Connector (OSTI)

The holographic dark energy model is proposed by Li as an attempt for probing the nature of dark energy within the framework of quantum gravity. The main characteristic of holographic dark energy is governed by a numerical parameter c in the model. The parameter c can only be determined by observations. Thus, in order to characterize the evolving feature of dark energy and to predict the fate of the Universe, it is of extraordinary importance to constrain the parameter c by using the currently available observational data. In this paper, we derive constraints on the holographic dark energy model from the latest observational data including the gold sample of 182 type Ia supernovae (SNIa), the shift parameter of the cosmic microwave background (CMB) given by the three-year Wilkinson Microwave Anisotropy Probe (WMAP) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). The joint analysis gives the fit results in 1-?: c=0.91-0.18+0.26 and ?m0=0.29±0.03. That is to say, though the possibility of c1 cannot be excluded in one-sigma error range, which is somewhat different from the result derived from previous investigations using earlier data. So, according to the new data, the evidence for the quintom feature in the holographic dark energy model is not as strong as before.

Xin Zhang and Feng-Quan Wu

2007-07-06T23:59:59.000Z

45

Preliminary Results from the Cosmic Background Imager  

E-Print Network (OSTI)

The Cosmic Background Imager (CBI) is a 13-element interferometer designed to image intrinsic anisotropies in the cosmic microwave background (CMB) on arcminute scales. A review of the capabilities of the instrument is presented, together with a discussion of observations which have been taken over the past 9 months from the Atacama desert of Chile. We present preliminary high-resolution mosaiced images of the CMB obtained from recent CBI data and discuss topics which the CBI will address in the near future.

B. S. Mason; J. K. Cartwright; S. Padin; T. J. Pearson; A. C. S. Readhead; M. Shepherd; J. Sievers; P. Udomprasert

2001-01-11T23:59:59.000Z

46

The Anisotropy of the Microwave Background to l = 3500: Deep Field Observations with the Cosmic Background Imager  

E-Print Network (OSTI)

We report measurements of anisotropy in the cosmic microwave background radiation over the multipole range l ~ 200 - 3500 with the Cosmic Background Imager based on deep observations of three fields. These results confirm the drop in power with increasing l first reported in earlier measurements with this instrument, and extend the observations of this decline in power out to l \\~ 2000. The decline in power is consistent with the predicted damping of primary anisotropies. At larger multipoles, l = 2000 - 3500, the power is 3.1 sigma greater than standard models for intrinsic microwave background anisotropy in this multipole range, and 3.5 sigma greater than zero. This excess power is not consistent with expected levels of residual radio source contamination but, for sigma_8 >~ 1, is consistent with predicted levels due to a secondary Sunyaev-Zeldovich anisotropy. Further observations are necessary to confirm the level of this excess and, if confirmed, determine its origin.

B. S. Mason; T. J. Pearson; A. C. S. Readhead; M. C. Shepherd; J. L. Sievers; P. S. Udomprasert; J. K. Cartwright; A. J. Farmer; S. Padin; S. T. Myers; J. R. Bond; C. R. Contaldi; U. -L. Pen; S. Prunet; D. Pogosyan; J. E. Carlstrom; J. Kovac; E. M. Leitch; C. Pryke; N. W. Halverson; W. L. Holzapfel; P. Altamirano; L. Bronfman; S. Casassus; J. May; M. Joy

2002-05-22T23:59:59.000Z

47

3D Weak Gravitational Lensing of the CMB and Galaxies  

E-Print Network (OSTI)

In this paper we present a power spectrum formalism that combines the full three-dimensional information from the galaxy ellipticity field, with information from the cosmic microwave background (CMB). We include in this approach galaxy cosmic shear and galaxy intrinsic alignments, CMB deflection, CMB temperature and CMB polarisation data; including the inter-datum power spectra between all quantities. We apply this to forecasting cosmological parameter errors for CMB and imaging surveys and show that the additional covariance between the CMB and ellipticity measurements can improve galaxy intrinsic alignment measurements by a factor of two, and dark energy equation of state measurements by thirty percent. We present predictions for Euclid-like, KiDS, ACTPoL, and CoRE-like experiments and show that the combination of cosmic shear and the CMB, from Euclid-like and CoRE-like experiments, can measure the sum of neutrino masses with an error of 0.02 eV, and the dark energy equation of state with an error on w0 of ...

Kitching, T D; Das, S

2014-01-01T23:59:59.000Z

48

Modified gravity and the CMB  

Science Journals Connector (OSTI)

We consider the effect of modified gravity on the peak structure of the cosmic microwave background (CMB) spectrum. We focus on simple models of modified gravity mediated by a massive scalar field coupled to both baryons and cold dark matter. This captures the features of chameleon, symmetron, dilaton, and f(R) models. We find that the CMB peaks can be affected in three independent ways provided the Compton radius of the massive scalar is not far-off the sound horizon at last scattering. When the coupling of the massive scalar to cold dark matter is large, the anomalous growth of the cold dark matter perturbation inside the Compton radius induces a change in the peak amplitudes. When the coupling to baryons is moderately large, the speed of sound is modified and the peaks shifted to higher momenta. Finally when both couplings are nonvanishing, a new contribution proportional to the Newton potential appears in the Sachs-Wolfe temperature and increases the peak amplitudes. We also show how, given any temporal evolution of the scalar field mass, one can engineer a corresponding modified gravity model of the chameleon type. This opens up the possibility of having independent constraints on modified gravity from the CMB peaks and large scale structures at low redshifts.

Philippe Brax and Anne-Christine Davis

2012-01-10T23:59:59.000Z

49

New operator approach to the CMB aberration kernels in harmonic space  

E-Print Network (OSTI)

Aberration kernels describe how harmonic-space multipole coefficients of cosmic microwave background (CMB) observables transform under Lorentz boosts of the reference frame. For spin-weighted CMB observables, transforming like the CMB temperature (i.e. Doppler weight $d = 1$), we show that the aberration kernels are the matrix elements of a unitary boost operator in harmonic space. Algebraic properties of the rotation and boost generators then give simple, exact recursion relations that allow us to raise or lower the multipole quantum numbers $\\ell$ and $m$, and the spin weight $s$. Further recursion relations express kernels of other Doppler weights $d \

Liang Dai; Jens Chluba

2014-03-24T23:59:59.000Z

50

Sky maps without anisotropies in the cosmic microwave background are a better fit to WMAP's uncalibrated time ordered data than the official sky maps  

E-Print Network (OSTI)

The purpose of this reanalysis of the WMAP uncalibrated time ordered data (TOD) was two fold. The first was to reassess the reliability of the detection of the anisotropies in the official WMAP sky maps of the cosmic microwave background (CMB). The second was to assess the performance of a proposed criterion in avoiding systematic error in detecting a signal of interest. The criterion was implemented by testing the null hypothesis that the uncalibrated TOD was consistent with no anisotropies when WMAP's hourly calibration parameters were allowed to vary. It was shown independently for all 20 WMAP channels that sky maps with no anisotropies were a better fit to the TOD than those from the official analysis. The recently launched Planck satellite should help sort out this perplexing result.

Keith S. Cover

2009-09-02T23:59:59.000Z

51

Detectability of the 21 cm-CMB cross-correlation from the EoR  

E-Print Network (OSTI)

The 21-cm line fluctuations and the cosmic microwave background (CMB) are powerful probes of the epoch of reionisation of the universe. We study the potential of the cross-correlation between 21-cm line fluctuations and CMB anisotropy to obtain further constraints on the reionisation history. We compute analytically the 21-cm cross-correlation with the CMB temperature anisotropy and polarisation, and we calculate the signal-to-noise (SN) ratio for its detection with Planck together with LOFAR, MWA and SKA. We find, on the one hand, that the 21-cm cross-correlation signal with CMB polarisation from the instant reionisation can be detected with an SN ratio of $\\sim 1$ for LOFAR and $\\sim 10$ for SKA. On the other hand, we confirm that the detection of the 21-cm cross-correlation with CMB polarisation is practically infeasible.

Tashiro, Hiroyuki; Langer, Mathieu; Douspis, Marian; Zaroubi, Saleem; Jelic, Vibor

2009-01-01T23:59:59.000Z

52

Evidence for a non-zero Lambda and a low matter density from a combined analysis of the 2dF Galaxy Redshift Survey and Cosmic Microwave Background Anisotropies  

E-Print Network (OSTI)

We perform a joint likelihood analysis of the power spectra of the 2dF Galaxy Redshift Survey (2dFGRS) and the cosmic microwave background (CMB) anisotropies under the assumptions that the initial fluctuations were adiabatic, Gaussian and well described by power laws with scalar and tensor indices of n_s and n_t. On its own, the 2dFGRS sets tight limits on the parameter combination Omega_m h, but relatively weak limits on the fraction of the cosmic matter density in baryons Omega_b/Omega_m. The CMB anisotropy data alone set poor constraints on the cosmological constant and Hubble constant because of a `geometrical degeneracy' among parameters. Furthermore, if tensor modes are allowed, the CMB data allow a wide range of values for the physical densities in baryons and cold dark matter. Combining the CMB and 2dFGRS data sets helps to break both the geometrical and tensor mode degeneracies. The values of the parameters derived here are consistent with the predictions of the simplest models of inflation, with the baryon density derived from primordial nucleosynthesis and with direct measurements of the Hubble parameter. In particular, we find strong evidence for a positive cosmological constant with a pm 2sigma range of 0.65 < Omega_Lambda < 0.85, completely independently of constraints on Omega_\\Lambda derived from Type Ia supernovae.

George Efstathiou; Stephen Moody; John A. Peacock; Will J. Percival; Carlton Baugh; Joss Bland-Hawthorn; Terry Bridges; Russell Cannon; Shaun Cole; Matthew Colless; Chris Collins; Warrick Couch; Gavin Dalton; Roberto De Propis; Simon P. Driver; Richard S. Ellis; Carlos S. Frenk; Karl Glazebrook; Carole Jackson; Ofer Lahav; Ian Lewis; Stuart Lumsden; Steve Maddox; Peder Norberg; Bruce A. Peterson; Will Sutherland; Keith Taylor

2001-09-10T23:59:59.000Z

53

Model-Independent Test for Scale-Dependent Non-Gaussianities in the Cosmic Microwave Background  

Science Journals Connector (OSTI)

We present a model-independent method to test for scale-dependent non-Gaussianities in combination with scaling indices as test statistics. Therefore, surrogate data sets are generated, in which the power spectrum of the original data is preserved, while the higher order correlations are partly randomized by applying a scale-dependent shuffling procedure to the Fourier phases. We apply this method to the Wilkinson Microwave Anisotropy Probe data of the cosmic microwave background and find signatures for non-Gaussianities on large scales. Further tests are required to elucidate the origin of the detected anomalies.

C. Räth, G. E. Morfill, G. Rossmanith, A. J. Banday, and K. M. Górski

2009-03-31T23:59:59.000Z

54

Maximum entropy method for reconstruction of the CMB images  

E-Print Network (OSTI)

We propose a new approach for the accurate reconstruction of cosmic microwave background distributions from observations containing in addition to the primary fluctuations the radiation from unresolved extragalactic point sources and pixel noise. The approach uses some effective realizations of the well-known maximum entropy method and principally takes into account {\\it a priori} information about finiteness and spherical symmetry of the power spectrum of the CMB satisfying the Gaussian statistics.

A. T. Bajkova

2002-05-21T23:59:59.000Z

55

Probing non-Gaussianities in the cosmic microwave background on an incomplete sky using surrogates  

Science Journals Connector (OSTI)

We demonstrate the feasibility to generate surrogates by Fourier-based methods for an incomplete data set. This is performed for the case of a cosmic microwave background analysis, where astrophysical foreground emission, mainly present in the Galactic plane, is a major challenge. The shuffling of the Fourier phases for generating surrogates is now enabled by transforming the spherical harmonics into a new set of basis functions that are orthonormal on the cut sky. The results show that non-Gaussianities and hemispherical asymmetries in the cosmic microwave background as identified in several former investigations, can still be detected even when the complete Galactic plane (|b|<30°) is removed. We conclude that the Galactic plane cannot be the dominant source for these anomalies. The results point towards a violation of statistical isotropy.

G. Rossmanith, H. Modest, C. Räth, A. J. Banday, K. M. Górski, and G. Morfill

2012-10-15T23:59:59.000Z

56

REIONIZATION ON LARGE SCALES. III. PREDICTIONS FOR LOW-l COSMIC MICROWAVE BACKGROUND POLARIZATION AND HIGH-l KINETIC SUNYAEV-ZEL'DOVICH OBSERVABLES  

SciTech Connect

We present new predictions for cosmic microwave background (CMB) temperature (on small angular scales) and polarization (on large angular scales) anisotropies induced during the epoch of reionization (EoR). Using a novel method calibrated from radiation-hydrodynamic simulations, we model the EoR in large volumes (L ?> 2 Gpc h {sup –1}). We find that the EoR contribution to the kinetic Sunyaev-Zel'dovich power spectrum (patchy kSZ) ranges between ?0.6-2.8 ?K{sup 2} at l = 3000 for the explored parameter space. For each model, the patchy kSZ power spectrum is calculated from three large 15° × 15° maps for better numerical convergence. Decreasing the size of these maps biases the overall patchy kSZ power to higher values. We find that the amplitude of the patchy kSZ power spectrum at l = 3000 follows simple scalings of D{sub l=3000}{sup kSZ}? z-bar and D{sub l=3000}{sup kSZ}??{sub z}{sup 0.51} for the mean redshift ( z-bar ) and duration (?{sub z}) of reionization. Using the constraints on z-bar from the Wilkinson Microwave Anisotropy Probe seven year results and the lower limit on ?{sub z} from EDGES, we find a lower limit of ?0.4 ?K{sup 2} at l = 3000. Planck will infer the mean redshift from the Thomson optical depth imprinted in the low-l polarization power spectrum. Future measurements of the high-l CMB power spectrum from the Atacama Cosmology Telescope and South Pole Telescope should detect the patchy kSZ signal if the cross correlation between the thermal SZ effect and the cosmic infrared background is constrained. We show that the combination of temperature and polarization measurements constrains both z-bar and ?{sub z}. The patchy kSZ maps, power spectra templates, and the polarization power spectra will be publicly available.

Battaglia, N.; Natarajan, A.; Trac, H. [McWilliams Center for Cosmology, Wean Hall, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh PA 15213 (United States); Cen, R. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Loeb, A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-10-20T23:59:59.000Z

57

Morphing the CMB: a technique for interpolating power spectra  

E-Print Network (OSTI)

The confrontation of the Cosmic Microwave Background (CMB) theoretical angular power spectrum with available data often requires the calculation of large numbers of power spectra. The standard practice is to use a fast code to compute the CMB power spectra over some large parameter space, in order to estimate likelihoods and constrain these parameters. But as the dimensionality of the space under study increases, then even with relatively fast anisotropy codes, the computation can become prohibitive. This paper describes the employment of a "morphing" strategy to interpolate new power spectra based on previously calculated ones. We simply present the basic idea here, and illustrate with a few examples; optimization of interpolation schemes will depend on the specific application. In addition to facilitating the exploration of large parameter spaces, this morphing technique may be helpful for Fisher matrix calculations involving derivatives.

Kris Sigurdson; Douglas Scott

2000-03-16T23:59:59.000Z

58

A Polarization Sensitive Bolometric Detector for Observations of the Cosmic Microwave Background  

E-Print Network (OSTI)

We have developed a bolometric detector that is intrinsically sensitive to linear polarization which is optimized for making measurements of the polarization of the cosmic microwave background radiation. The receiver consists of a pair of co-located silicon nitride micromesh absorbers which couple anisotropically to linearly polarized radiation through a corrugated waveguide structure. This system allows simultaneous background limited measurements of the Stokes I and Q parameters over ~ 30% bandwidths at frequencies from ~ 60 to 600 GHz. Since both linear polarizations traverse identical optical paths from the sky to the point of detection, the susceptibility to systematic effects is minimized. The amount of uncorrelated noise between the two polarization senses is limited to the quantum limit of thermal and photon shot noise, while drifts in the relative responsivity to orthogonal polarizations are limited to the effect of non-uniformity in the thin film deposition of the leads and the intrinsic thermistor properties. Devices using NTD Ge thermistors have achieved NEPs of 2 x 10^{-17} W/sqrt{Hz} with a 1/f knee below 100 mHz at a base temperature of 270 mK. Numerical modelling of the structures has been used to optimize the bolometer geometry and coupling to optics. Comparisons of numerical results and experimental data are made. A description of how the quantities measured by the device can be interpreted in terms of the Stokes parameters is presented. The receiver developed for the Boomerang and Planck HFI focal planes is presented in detail.

W. C. Jones; R. S. Bhatia; J. J. Bock; A. E. Lange

2002-09-08T23:59:59.000Z

59

Gravitational-Wave Stochastic Background from Cosmic Strings  

Science Journals Connector (OSTI)

We consider the stochastic background of gravitational waves produced by a network of cosmic strings and assess their accessibility to current and planned gravitational wave detectors, as well as to big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and pulsar timing constraints. We find that current data from interferometric gravitational wave detectors, such as Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds. Future more sensitive LIGO runs and interferometers such as Advanced LIGO and Laser Interferometer Space Antenna (LISA) will be able to explore substantial parts of the parameter space.

Xavier Siemens; Vuk Mandic; Jolien Creighton

2007-03-13T23:59:59.000Z

60

Re-Ionization and its Imprint on the Cosmic Microwave Background  

E-Print Network (OSTI)

Early reionization changes the pattern of anisotropies expected in the cosmic microwave background. To explore these changes, we derive from first principles the equations governing anisotropies, focusing on the interactions of photons with electrons. Vishniac (1987) claimed that second order terms can be large in a re-ionized Universe, so we derive equations correct to second order in the perturbations. There are many more second order terms than were considered by Vishniac. To understand the basic physics involved, we present a simple analytic approximation to the first order equation. Then turning to the sec- ond order equation, we show that the Vishniac term is indeed the only important one. We also present numerical results for a variety of ionization histories [in a standard cold dark matter Universe] and show quantitatively how the sig- nal in several experiments depends on the ionization history. The most pronounced indication of a re-ionized Universe would be seen in very small scale experiments; the expected signal in the Owens Valley experiment is smaller by a factor of order ten if the last scattering surface is at a redshift $z\\simeq100$ as it would be if the Universe were re-ionized very early. On slightly larger scales, the expected signal in a re-ionized Universe {\\it is} smaller than it would be with standard recombination, but only by a factor of two or so.

Scott Dodelson; Jay Jubas

1993-08-16T23:59:59.000Z

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61

Gravitational-wave stochastic background from kinks and cusps on cosmic strings  

Science Journals Connector (OSTI)

We compute the contribution of kinks on cosmic string loops to stochastic background of gravitational waves (SBGW). We find that kinks contribute at the same order as cusps to the SBGW. We discuss the accessibility of the total background due to kinks as well as cusps to current and planned gravitational-wave detectors, as well as to the big bang nucleosynthesis (BBN), the cosmic microwave background (CMB), and pulsar timing constraints. As in the case of cusps, we find that current data from interferometric gravitational-wave detectors, such as LIGO, are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds.

S. Ölmez; V. Mandic; X. Siemens

2010-05-13T23:59:59.000Z

62

Cosmological origin of anomalous radio background  

SciTech Connect

The ARCADE 2 collaboration has reported a significant excess in the isotropic radio background, whose homogeneity cannot be reconciled with clustered sources. This suggests a cosmological origin prior to structure formation. We investigate several potential mechanisms and show that injection of relativistic electrons through late decays of a metastable particle can give rise to the observed excess radio spectrum through synchrotron emission. However, constraints from the cosmic microwave background (CMB) anisotropy, on injection of charged particles and on the primordial magnetic field, present a challenge. The simplest scenario is with a ?>9 GeV particle decaying into e{sup +}e{sup ?} at a redshift of z ? 5, in a magnetic field of ? 5?G, which exceeds the CMB B-field constraints, unless the field was generated after decoupling. Decays into exotic millicharged particles can alleviate this tension, if they emit synchroton radiation in conjunction with a sufficiently large background magnetic field of a dark U(1)' gauge field.

Cline, James M. [Department of Physics, McGill University, 3600 Rue University, Montréal, Québec, H3A 2T8 Canada (Canada); Vincent, Aaron C., E-mail: jcline@physics.mcgill.ca, E-mail: vincent@ific.uv.es [Instituto de Física Corpuscular, Universitat de València - CSIC, 46071, Valencia (Spain)

2013-02-01T23:59:59.000Z

63

Novel calibration system with sparse wires for CMB polarization receivers  

SciTech Connect

B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP

2011-07-01T23:59:59.000Z

64

BACKGROUND  

NLE Websites -- All DOE Office Websites (Extended Search)

BACKGROUND The safe and environmentally conscious performance of work is a fundamental core value of the Hanford Advisory Board. The Department of Energy (DOE) in seeking to move...

65

BACKGROUND  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Emergency Medical Coordination Emergency Medical Coordination Memorandum of Agreement at Brookhaven National Laboratory DOE/IG-0594 March 2003 Department of Energy Washington, DC 20585 March 3 1,2003 FROM: Inspector General SUBJECT: INFORMATION: Report on Inspection of "Emergency Medical Coordination Memorandum of Agreement at Brookhaven National Laboratory" BACKGROUND Because of possible exposure to radioactive and hazardous materials and the potential for industrial accidents at Department of Energy (DOE) sites, the Department has established formalized agreements with local emergency medical providers. These arrangements are generally documented through memoranda of agreements (MOAs). These documents detail the m u

66

Background  

Office of Legacy Management (LM)

explains the potential health hazards associated with air quality related to the removal and storage of explains the potential health hazards associated with air quality related to the removal and storage of mill tailings and other contaminated materials. Background From 1942 to 1960, uranium ore was processed at the Monticello mill in southeast Utah. When the mill was closed, approximately 2.3 million cubic yards of low-level radioactive mill tailings, contaminated soil, and other miscellaneous debris remained on the site. The U.S. Department of Energy (DOE) Grand Junction Projects Office, in conjunction with the U.S. Environmental Protection Agency (EPA) and the State of Utah, is conducting the cleanup of the millsite and more than 400 area homes and businesses contaminated with mill tailings. The purpose of the cleanup is to minimize risks to the public and the

67

Background  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Format for the one pager: Report Statement/Recommendation Format for the one pager: Report Statement/Recommendation Background Pros/Cons discussion We would like to see good drafts by noon. 3/30/01. 11 circulate them as soon as I get them in. Any questions, give me a call. 456-7874 Charlie ___ ___ _8171 DOE015-1514 Martin, Adrienne ^ From: Anderson, Margot / / Sent: Thursday, March 29, 2001 723 PM To: 'Andrew D. Lundquisltovp.eop.gov%intemet' Subject: RE: 1 spoke with Charlie and we got it fixed. Thanksl -Original Message- From: Andrew D. Lundquist@ovp.eop.gov%intemet Imailto:Andrew D. Lundquistovp.eop.gov] Sent: Thursday March 29, 2001 7:18 PM To: Anderson. Margot Cc: Kelliher, Joseph; Kolevar, Kevin; Charles M. Smthovp.egov%htemet; Juleanna FR GOovsWeovp.eop.gov%intemet 'kmurphyiosec.doc.gov%intemet 'dina.eisOdo.treas.gov%intemer;

68

Background  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Patent Rights in the New Patent Rights in the New Independent States (NIS) of the Former Soviet Union for Inventions made by NIS institutes' employeess in the course of or under agreements entered into pursuant to the Fiscal Year 1994 Foreign Operations Appropriations Act (P.L. 103- 87). W(C) 94-001 Background The dissolution of the Soviet Union and the drastic reductions in defense spending by the NIS have created an extremely difficult situation for the scientists and engineers who are responsible for the former Soviet Union's defense technology base. It is estimated that there are several tens of thousands of such scientists and engineers; they possess critical technical knowledge about weapons of mass destruction and are underemployed and undercompensated, and consequently, could contribute to

69

SPIDER: A Balloon-borne Large-scale CMB Polarimeter  

E-Print Network (OSTI)

Spider is a balloon-borne experiment that will measure the polarization of the Cosmic Microwave Background over a large fraction of a sky at 1 degree resolution. Six monochromatic refracting millimeter-wave telescopes with large arrays of antenna-coupled transition-edge superconducting bolometers will provide system sensitivities of 4.2 and 3.1 micro K_cmb rt s at 100 and 150 GHz, respectively. A rotating half-wave plate will modulate the polarization sensitivity of each telescope, controlling systematics. Bolometer arrays operating at 225 GHz and 275 GHz will allow removal of polarized galactic foregrounds. In a 2-6 day first flight from Alice Springs, Australia in 2010, Spider will map 50% of the sky to a depth necessary to improve our knowledge of the reionization optical depth by a large factor.

B. P. Crill; P. A. R. Ade; E. S. Battistelli; S. Benton; R. Bihary; J. J. Bock; J. R. Bond; J. Brevik; S. Bryan; C. R. Contaldi; O. Dore; M. Farhang; L. Fissel; S. R. Golwala; M. Halpern; G. Hilton; W. Holmes; V. V. Hristov; K. Irwin; W. C. Jones; C. L. Kuo; A. E. Lange; C. Lawrie; C. J. MacTavish; T. G. Martin; P. Mason; T. E. Montroy; C. B. Netterfield; E. Pascale; D. Riley; J. E. Ruhl; M. C. Runyan; A. Trangsrud; C. Tucker; A. Turner; M. Viero; D. Wiebe

2008-07-09T23:59:59.000Z

70

Cross-correlation of the cosmic microwave background with the 2MASS galaxy survey: Signatures of dark energy, hot gas, and point sources  

Science Journals Connector (OSTI)

We cross-correlate the cosmic microwave background temperature anisotropies observed by the Wilkinson Microwave Anisotropy Probe (WMAP) with the projected distribution of extended sources in the Two Micron All Sky Survey (2MASS). By modeling the theoretical expectation for this signal, we extract the signatures of dark energy [integrated Sachs-Wolfe effect (ISW)], hot gas [thermal Sunyaev-Zeldovich (SZ) effect], and microwave point sources in the cross-correlation. Our strongest signal is the thermal SZ, at the 3.1–3.7? level, which is consistent with the theoretical prediction based on observations of x-ray clusters. We also see the ISW signal at the 2.5? level, which is consistent with the expected value for the concordance ?CDM cosmology, and is an independent signature of the presence of dark energy in the Universe. Finally, we see the signature of microwave point sources at the 2.7? level.

Niayesh Afshordi; Yeong-Shang Loh; Michael A. Strauss

2004-04-28T23:59:59.000Z

71

An estimator for statistical anisotropy from the CMB bispectrum  

SciTech Connect

Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial vector fields in inflationary theories which generally display some level of statistical anisotropy both in the power spectrum and in higher-order correlation functions. Motivated by these observations and the recent theoretical developments in the study of primordial vector fields, we develop the formalism necessary to extract statistical anisotropy information from the three-point function of the CMB temperature anisotropy. We employ a simplified vector field model and parametrize the bispectrum of curvature fluctuations in such a way that all the information about statistical anisotropy is encoded in some parameters ?{sub LM} (which measure the anisotropic to the isotropic bispectrum amplitudes). For such a template bispectrum, we compute an optimal estimator for ?{sub LM} and the expected signal-to-noise ratio. We estimate that, for f{sub NL} ? 30, an experiment like Planck can be sensitive to a ratio of the anisotropic to the isotropic amplitudes of the bispectrum as small as 10%. Our results are complementary to the information coming from a power spectrum analysis and particularly relevant for those models where statistical anisotropy turns out to be suppressed in the power spectrum but not negligible in the bispectrum.

Bartolo, N.; Dimastrogiovanni, E.; Matarrese, S. [Dipartimento di Fisica ''G. Galilei'', Università degli Studi di Padova, via Marzolo 8, 35131 Padova (Italy); Liguori, M. [Institut d'Astrophysique de Paris, UMR-7095 du CNRS, Université Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris (France); Riotto, A., E-mail: nicola.bartolo@pd.infn.it, E-mail: dimastro@pd.infn.it, E-mail: liguori@iap.fr, E-mail: sabino.matarrese@pd.infn.it, E-mail: riotto@mail.cern.ch [INFN — Sezione di Padova, via Marzolo 8, 35131 Padova (Italy)

2012-01-01T23:59:59.000Z

72

Conformal invariance, dynamical dark energy and the CMB  

SciTech Connect

Einstein's General Relativity receives quantum corrections relevant at cosmological distance scales. These effects arise from conformal scalar degrees of freedom in the extended Effective Field Theory (EFT) of gravity required by the trace anomaly of the quantum stress tensor in curved space. Scalar degrees of freedom in cosmology arise naturally from the effective action of the trace anomaly in the Standard Model, without the ad hoc introduction of an inflaton field. In the EFT including the trace anomaly terms, {Lambda}{sub eff} becomes dynamical and potentially dependent upon both space and time. The fluctuations of these anomaly scalars may also influence the spectrum and statistics of the Cosmic Microwave Background (CMB). Under the hypothesis that scale invariance should be promoted to full conformal invariance, an hypothesis supported by the embedding of the conformal group of three dimensional flat sections in de Sitter space, the form of the CMB bi-spectrum can be fixed, and the tri-spectrum constrained. The angular spectra predicted by conformal invariance differ from those suggested by simple models of inflation.

Mottola, Emil [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

73

Joint Planck and WMAP Assessment of Low CMB Multipoles  

E-Print Network (OSTI)

The remarkable progress in cosmic microwave background (CMB) studies over past decade has led to the era of precision cosmology in striking agreement with the $\\Lambda$CDM model. However, the lack of power in the CMB temperature anisotropies at large angular scales (low-$\\ell$), as has been confirmed by the recent Planck data also (up to $\\ell=40$), is still an open problem. One can avoid to seek an explanation for this problem by attributing the lack of power to cosmic variance or can look for explanations i.e., different inflationary potentials or initial conditions for inflation to begin with, non-trivial topology, ISW effect etc. Features in the primordial power spectrum (PPS) motivated by the early universe physics has been the most common solution to address this problem. In the present work we also follow this approach and consider a set of PPS which have features and constrain the parameters of those using WMAP 9 year and Planck data employing Markov-Chain Monte Carlo (MCMC) analysis. The prominent fe...

Iqbal, Asif; Souradeep, Tarun; Malik, Manzoor A

2015-01-01T23:59:59.000Z

74

Limits on the Polarization of the Cosmic Microwave Background Radiation at Multipoles up to l~2000  

E-Print Network (OSTI)

We report upper limits on the polarization of the CMBR as measured with the Cosmic Background Imager, a 13 element interferometer that operates in the 26-36 GHz band and is sited on Llano de Chajnantor in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a steerable platform that can be rotated about the optical axis to facilitate polarization observations. The CBI employs single-mode circularly polarized receivers and it samples multipoles from l~400 to l~3500. The polarization data were calibrated on 3C279 and Tau A. The polarization observations consist of 278 hours of data on two fields taken in 2000, during the first CBI observing season. A joint likelihood analysis of the two fields yields three upper limits (95% c.l.) for \\mathcal{C}_l^{EE} = C^{EE}l(l+1)/(2pi) under the assumption that \\mathcal{C}_l^{BB}=0: 49.0 microK^2 (l=603); 164 microK^2 (l=1144); and 630 microK^2 (l=2048).

J. K. Cartwright; T. J. Pearson; A. C. S. Readhead; M. C. Shepherd; J. L. Sievers; G. B. Taylor

2005-02-08T23:59:59.000Z

75

FOREGROUND PREDICTIONS FOR THE COSMIC MICROWAVE BACKGROUND POWER SPECTRUM FROM MEASUREMENTS OF FAINT INVERTED RADIO SOURCES AT 5 GHz  

SciTech Connect

We present measurements of a population of matched radio sources at 1.4 and 5 GHz down to a flux limit of 1.5 mJy in 7 deg{sup 2} of the NOAO Deep Field South. We find a significant fraction of sources with inverted spectral indices that all have 1.4 GHz fluxes less than 10 mJy and are therefore too faint to have been detected and included in previous radio source count models that are matched at multiple frequencies. Combined with the matched source population at 1.4 and 5 GHz in 1 deg{sup -2} in the ATESP survey, we update models for the 5 GHz differential number counts and distributions of spectral indices in 5 GHz flux bins that can be used to estimate the unresolved point source contribution to the cosmic microwave background temperature anisotropies. We find a shallower logarithmic slope in the 5 GHz differential counts than in previously published models for fluxes {approx}< 100 mJy as well as larger fractions of inverted spectral indices at these fluxes. Because the Planck flux limit for resolved sources is larger than 100 mJy in all channels, our modified number counts yield at most a 10% change in the predicted Poisson contribution to the Planck temperature power spectrum. For a flux cut of 5 mJy with the South Pole Telescope and a flux cut of 20 mJy with the Atacama Cosmology Telescope, we predict a {approx}30% and {approx}10% increase, respectively, in the radio source Poisson power in the lowest frequency channels of each experiment relative to that predicted by previous models.

Schneider, Michael D. [Lawrence Livermore National Laboratory, P.O. Box 808 L-210, Livermore, CA 94551 (United States); Becker, Robert H. [Department of Physics, University of California, One Shields Avenue, Davis, CA 08991 (United States); De Vries, Willem [Lawrence Livermore National Laboratory, P.O. Box 808 L-211, Livermore, CA 94551 (United States); White, Richard L., E-mail: schneider42@llnl.gov [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2012-05-10T23:59:59.000Z

76

Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra  

E-Print Network (OSTI)

We constrain flat cosmological models with a joint likelihood analysis of a new compilation of data from the cosmic microwave background (CMB) and from the 2dF Galaxy Redshift Survey (2dFGRS). Fitting the CMB alone yields a known degeneracy between the Hubble constant h and the matter density Omega_m, which arises mainly from preserving the location of the peaks in the angular power spectrum. This `horizon-angle degeneracy' is considered in some detail and shown to follow a simple relation Omega_m h^{3.4} = constant. Adding the 2dFGRS power spectrum constrains Omega_m h and breaks the degeneracy. If tensor anisotropies are assumed to be negligible, we obtain values for the Hubble constant h=0.665 +/- 0.047, the matter density Omega_m=0.313 +/- 0.055, and the physical CDM and baryon densities Omega_c h^2 = 0.115 +/- 0.009, Omega_b h^2 = 0.022 +/- 0.002 (standard rms errors). Including a possible tensor component causes very little change to these figures; we set a upper limit to the tensor-to-scalar ratio of r<0.7 at 95% confidence. We then show how these data can be used to constrain the equation of state of the vacuum, and find w<-0.52 at 95% confidence. The preferred cosmological model is thus very well specified, and we discuss the precision with which future CMB data can be predicted, given the model assumptions. The 2dFGRS power-spectrum data and covariance matrix, and the CMB data compilation used here, are available from http://www.roe.ac.uk/~wjp/

Will J. Percival; Will Sutherland; John A. Peacock; Carlton M. Baugh; Joss Bland-Hawthorn; Terry Bridges; Russell Cannon; Shaun Cole; Matthew Colless; Chris Collins; Warrick Couch; Gavin Dalton; Roberto De Propris; Simon P. Driver; George Efstathiou; Richard S. Ellis; Carlos S. Frenk; Karl Glazebrook; Carole Jackson; Ofer Lahav; Ian Lewis; Stuart Lumsden; Steve Maddox; Stephen Moody; Peder Norberg; Bruce A. Peterson; Keith Taylor

2002-08-22T23:59:59.000Z

77

Oxygen pumping II: Probing the Inhomogeneous Metal Enrichment at the Epoch of Reionization with High Frequency CMB Observations  

E-Print Network (OSTI)

At the epoch of reionization, when the high-redshift inter-galactic medium (IGM) is being enriched with metals, the 63.2 micron fine structure line of OI is pumped by the ~ 1300 AA soft UV background and introduces a spectral distortion in the Cosmic Microwave Background (CMB). Here we use a toy model for the spatial distribution of neutral oxygen, assuming metal bubbles surround dark matter halos, and compute the fluctuations of this distortion, and the angular power spectrum it imprints on the CMB. We discuss the dependence of the power spectrum on the velocity of the winds polluting the IGM with metals, the minimum mass of the halos producing these winds, and on the cosmic epoch when the OI pumping occurs. We find that, although the clustering signal of the CMB distortion is weak \\delta y_{rms} ~ 10^{-7} (roughly corresponding to a temperature anisotropy of few nK), it may be reachable in deep integrations with high-sensitivity infrared detectors. Even without a detection, these instruments should be able to useful constraints on the heavy element enrichment history of the IGM.

Carlos Hernandez-Monteagudo; Zoltan Haiman; Licia Verde; Raul Jimenez

2007-09-20T23:59:59.000Z

78

The Cosmic Background Imager  

E-Print Network (OSTI)

The Cosmic Background Imager (CBI) is an instrument designed to make images of the cosmic microwave background radiation and to measure its statistical properties on angular scales from about 3 arc minutes to one degree (spherical harmonic scales from l ~ 4250 down to l ~ 400). The CBI is a 13-element interferometer mounted on a 6 meter platform operating in ten 1-GHz frequency bands from 26 GHz to 36 GHz. The instantaneous field of view of the instrument is 45 arcmin (FWHM) and its resolution ranges from 3 to 10 arcmin; larger fields can be imaged by mosaicing. At this frequency and resolution, the primary foreground is due to discrete extragalactic sources, which are monitored at the Owens Valley Radio Observatory and subtracted from the CBI visibility measurements. The instrument has been making observations since late 1999 of both primordial CMB fluctuations and the Sunyaev-Zeldovich effect in clusters of galaxies from its site at an altitude of 5080 meters near San Pedro de Atacama, in northern Chile. Observations will continue until August 2001 or later. We present preliminary results from the first few months of observations.

T. J. Pearson; B. S. Mason; S. Padin; A. C. S. Readhead; M. C. Shepherd; J. Sievers; P. S. Udomprasert; J. K. Cartwright

2000-12-11T23:59:59.000Z

79

Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps  

SciTech Connect

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few ?K which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.

Sunyaev, Rashid A.; Khatri, Rishi, E-mail: sunyaev@mpa-garching.mpg.de, E-mail: khatri@mpa-garching.mpg.de [Max Planck Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)

2013-03-01T23:59:59.000Z

80

CMB ANISOTROPIES: AN OVERVIEW  

E-Print Network (OSTI)

A brief outline of the current status of CMB anisotropies and what they might mean, heavily biased towards the perspective of Berkeley theorists. Based on a talk presented at the 17th Texas Symposium on Relativistic Astrophysics held in Munich, December 1994.

Douglas Scott

1995-02-02T23:59:59.000Z

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81

Statistical isotropy violation of the CMB brightness fluctuations  

SciTech Connect

Certain anomalies at large angular scales in the cosmic microwave background (CMB) measured by WMAP have been suggested as possible evidence of breakdown of statistical isotropy (SI). SI violation of cosmological perturbations is a generic feature of ultralarge scale structure of the cosmos and breakdown of global symmetries. Most CMB photons free-stream to the present from the surface of last scattering. It is thus reasonable to expect statistical isotropy violation in the CMB photon distribution observed now to have originated from SI violation in the baryon-photon fluid at last scattering, in addition to anisotropy of the primordial power spectrum studied earlier in the literature. We consider the generalized anisotropic brightness distribution fluctuations, {Delta}(k-vector, n-circumflex, {tau}) (at conformal time {tau}) in contrast to the SI case where it is simply a function of |k-vector| and k-circumflex{center_dot}n-circumflex. The brightness fluctuations expanded in bipolar spherical harmonic (BipoSH) series can then be written as {Delta}{sub l{sub 1}}{sub l{sub 2}}{sup LM}(k,{tau}), where L>0 terms encode deviations from statistical isotropy. Violation of SI encoded in the present off-diagonal elements of the harmonic space correlation , equivalently, the BipoSH coefficients A{sub ll}{sup 'LM}, are then related to the generalized BipoSH brightness fluctuation terms at present. We study the evolution of {Delta}{sub l{sub 1}}{sub l{sub 2}}{sup LM}(k,{tau}) from nonzero terms {Delta}{sub l{sub 3}}{sub l{sub 4}}{sup LM}(k,{tau}{sub s}) at last scattering, in the free-streaming regime. We show that the terms with given BipoSH multipole LM evolve independently. Moreover, similar to the SI case, power at small spherical harmonic (SH) multipoles of {Delta}{sub l{sub 3}}{sub l{sub 4}}{sup LM}(k,{tau}{sub s}) at the last scattering is transferred to {Delta}{sub l{sub 1}}{sub l{sub 2}}{sup LM}(k,{tau}) at larger SH multipoles. The structural similarity is more apparent in the asymptotic expression for large values of the final SH multipoles. This formalism allows an elegant identification of any SI violation observed today to a possible origin in SI violating physics present in the baryon-photon fluid. This is illustrated for the known result of SI violating angular correlations due to the presence of a homogeneous magnetic field in the baryon-photon fluid.

Aich, Moumita; Souradeep, Tarun [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411 007 (India)

2010-04-15T23:59:59.000Z

82

BOOMERanG: a scanning telescope for 10 arcminutes resolution CMB maps  

Science Journals Connector (OSTI)

The BOOMERanG experiment is a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment features a wide focal plane with 16 detectors in the frequency bands centered at 90 150 220 400 GHz with FWHM ranging between 18 and 10 arcmin. It will be flown on a long duration (7–14 days) flight circumnavigating Antarctica at the end of 1998. The instrument was flown with a reduced focal plane (6 detectors 90 and 150 GHz bands 25 to 15 arcmin FWHM) on a qualification flight from Texas in August 1997. A wide (?300 deg2 i.e. about 5000 independent beams at 150 GHz) sky area was mapped in the constellations of Capricornus Aquarius Cetus with very low foreground contamination. The instrument was calibrated using the CMB dipole and observations of Jupiter. The LDB version of the instrument has been qualified and shipped to Antarctica.

S. Masi; P. A. R. Ade; R. Artusa; J. J. Bock; A. Boscaleri; B. P. Crill; P. de Bernardis; G. De Troia; P. C. Farese; M. Giacometti; V. V. Hristov; A. Iacoangeli; A. E. Lange; A. T. Lee; L. Martinis; P. V. Mason; P. D. Mauskopf; F. Melchiorri; L. Miglio; T. Montroy; C. B. Netterfield; E. Pascale; F. Piacentini; P. L. Richards; G. Romeo; J. E. Ruhl; F. Scaramuzzi

1999-01-01T23:59:59.000Z

83

BOOMERanG: a scanning telescope for 10 arcminutes resolution CMB maps  

E-Print Network (OSTI)

The BOOMERanG experiment is a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment features a wide focal plane with 16 detectors in the frequency bands centered at 90, 150, 220, 400 GHz, with FWHM ranging between 18 and 10 arcmin. It will be flown on a long duration (7-14 days) flight circumnavigating Antarctica at the end of 1998. The instrument was flown with a reduced focal plane (6 detectors, 90 and 150 GHz bands, 25 to 15 arcmin FWHM) on a qualification flight from Texas, in August 1997. A wide (~300 sq. deg, i.e. about 5000 independent beams at 150 GHz) sky area was mapped in the constellations of Capricornus, Aquarius, Cetus, with very low foreground contamination. The instrument was calibrated using the CMB dipole and observations of Jupiter. The LDB version of the instrument has been qualified and shipped to Antarctica.

S. Masi; P. A. R. Ade; R. Artusa; J. J. Bock; A. Boscaleri; B. P. Crill; P. de Bernardis; G. De Troia; P. C. Farese; M. Giacometti; V. V. Hristov; A. Iacoangeli; A. E. Lange; A. T. Lee; L. Martinis; P. V. Mason; P. D. Mauskopf; F. Melchiorri; L. Miglio; T. Montroy; C. B. Netterfield; E. Pascale; F. Piacentini; P. L. Richards; G. Romeo; J. E. Ruhl; F. Scaramuzzi

1999-11-30T23:59:59.000Z

84

Maps of CMB lensing deflection from N-body simulations in Coupled Dark Energy Cosmologies  

SciTech Connect

We produce lensing potential and deflection-angle maps in order to simulate the weak gravitational lensing of the Cosmic Microwave Background (CMB) via ray-tracing through the COupled Dark Energy Cosmological Simulations (CoDECS), the largest suite of N-body simulations to date for interacting Dark Energy cosmologies. The constructed maps faithfully reflect the N-body cosmic structures on a range of scales going from the arcminute to the degree scale, limited only by the resolution and extension of the simulations. We investigate the variation of the lensing pattern due to the underlying Dark Energy (DE) dynamics, characterised by different background and perturbation behaviours as a consequence of the interaction between the DE field and Cold Dark Matter (CDM). In particular, we study in detail the results from three cosmological models differing in the background and perturbations evolution at the epoch in which the lensing cross section is most effective, corresponding to a redshift of ? 1, with the purpose to isolate their imprints in the lensing observables, regardless of the compatibility of these models with present constraints. The scenarios investigated here include a reference ?CDM cosmology, a standard coupled DE (cDE) scenario, and a ''bouncing'' cDE scenario. For the standard cDE scenario, we find that typical differences in the lensing potential result from two effects: the enhanced growth of linear CDM density fluctuations with respect to the ?CDM case, and the modified nonlinear dynamics of collapsed structures induced by the DE-CDM interaction. As a consequence, CMB lensing highlights the DE impact in the cosmological expansion, even in the degenerate case where the amplitude of the linear matter density perturbations, parametrised through ?{sub 8}, is the same in both the standard cDE and ?CDM cosmologies. For the ''bouncing'' scenario, we find that the two opposite behaviours of the lens density contrast and of the matter abundance lead to a counter-intuitive effect, making the power of the lensing signal in this model lower by 10% than in the ?CDM scenario. Moreover, we compare the behaviour of CDM and baryons in CoDECS separately, in order to isolate effects coming from the coupling with the DE component. We find that, in the bouncing scenario, baryons show an opposite trend with respect to CDM, due to the coupling of the latter with the DE component. These results confirm the relevance of CMB lensing as a probe for DE at the early stages of cosmic acceleration, and demonstrate the reliability of N-body based large scale CMB lensing simulations in the context of DE studies.

Carbone, Carmelita [INAF – Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (Italy); Baldi, Marco [Dipartimento di Fisica e Astronomia, Università di Bologna, Viale B. Pichat 6/2, I-40127 Bologna (Italy); Pettorino, Valeria [Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, 24 quai Ernest Ansermet, CH–1211 Genève 4 (Switzerland); Baccigalupi, Carlo, E-mail: carmelita.carbone@brera.inaf.it, E-mail: marco.baldi5@unibo.it, E-mail: valeria.pettorino@unige.ch, E-mail: bacci@sissa.it [SISSA, Via Bonomea 265, Trieste, I-34136 (Italy)

2013-09-01T23:59:59.000Z

85

Using SCUBA to place upper limits on arcsecond scale CMB anisotropies at 850 microns  

E-Print Network (OSTI)

The SCUBA instrument on the James Clerk Maxwell Telescope has already had an impact on cosmology by detecting relatively large numbers of dusty galaxies at high redshift. Apart from identifying well-detected sources, such data can also be mined for information about fainter sources and their correlations, as revealed through low level fluctuations in SCUBA maps. As a first step in this direction we analyse a small SCUBA data-set as if it were obtained from a Cosmic Microwave Background (CMB) differencing experiment. This enables us to place limits on CMB anisotropy at 850 microns. Expressed as Q_{flat}, the quadrupole expectation value for a flat power spectrum, the limit is 152 microKelvin at 95 per cent confidence, corresponding to C_0^{1/2} < 355 microKelvin for a Gaussian autocorrelation function, with a coherence angle of about 20--25 arcsec; These results could easily be reinterpretted in terms of any other fluctuating sky signal. This is currently the best limit for these scales at high frequency, and comparable to limits at similar angular scales in the radio. Even with such a modest data-set, it is possible to put a constraint on the slope of the SCUBA counts at the faint end, since even randomly distributed sources would lead to fluctuations. Future analysis of sky correlations in more extensive data-sets ought to yield detections, and hence additional information on source counts and clustering.

Colin Borys; Scott C. Chapman; Douglas Scott

1998-08-04T23:59:59.000Z

86

Primordial Magnetic Field Effects on the CMB and Large Scale Structure  

E-Print Network (OSTI)

Magnetic fields are everywhere in nature and they play an important role in every astronomical environment which involves the formation of plasma and currents. It is natural therefore to suppose that magnetic fields could be present in the turbulent high temperature environment of the big bang. Such a primordial magnetic field (PMF) would be expected to manifest itself in the cosmic microwave background (CMB) temperature and polarization anisotropies, and also in the formation of large- scale structure. In this review we summarize the theoretical framework which we have developed to calculate the PMF power spectrum to high precision. Using this formulation, we summarize calculations of the effects of a PMF which take accurate quantitative account of the time evolution of the cut off scale. We review the constructed numerical program, which is without approximation, and an improvement over the approach used in a number of previous works for studying the effect of the PMF on the cosmological perturbations. We demonstrate how the PMF is an important cosmological physical process on small scales. We also summarize the current constraints on the PMF amplitude $B_\\lambda$ and the power spectral index $n_B$ which have been deduced from the available CMB observational data by using our computational framework.

Dai G. Yamazaki; Kiyotomo Ichiki; Toshitaka Kajino; Grant J. Mathew

2011-12-21T23:59:59.000Z

87

A DIRECT MEASUREMENT OF THE LINEAR BIAS OF MID-INFRARED-SELECTED QUASARS AT z ? 1 USING COSMIC MICROWAVE BACKGROUND LENSING  

SciTech Connect

We measure the cross-power spectrum of the projected mass density as traced by the convergence of the cosmic microwave background lensing field from the South Pole Telescope (SPT) and a sample of Type 1 and 2 (unobscured and obscured) quasars at (z) ? 1 selected with the Wide-field Infrared Survey Explorer, over 2500 deg{sup 2}. The cross-power spectrum is detected at ?7?, and we measure a linear bias b = 1.61 ± 0.22, consistent with clustering analyses. Using an independent lensing map, derived from Planck observations, to measure the cross-spectrum, we find excellent agreement with the SPT analysis. The bias of the combined sample of Type 1 and 2 quasars determined in this work is similar to that previously determined for Type 1 quasars alone; we conclude that obscured and unobscured quasars trace the matter field in a similar way. This result has implications for our understanding of quasar unification and evolution schemes.

Geach, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom)] [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Hickox, R. C.; Hainline, K. N. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States)] [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Bleem, L. E.; Benson, B. A.; Bhattacharya, S.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)] [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States)] [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Holder, G. P.; De Haan, T.; Dobbs, M. A.; Dudley, J. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada)] [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States)] [University of Chicago, Chicago, IL 60637 (United States); Cho, H.-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States)] [NIST Quantum Devices Group, Boulder, CO 80305 (United States); George, E. M.; Holzapfel, W. L. [Department of Physics, University of California, Berkeley, CA 94720 (United States)] [Department of Physics, University of California, Berkeley, CA 94720 (United States); Halverson, N. W., E-mail: j.geach@herts.ac.uk [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); and others

2013-10-20T23:59:59.000Z

88

CMB anisotropy measurements using stratospheric balloons  

E-Print Network (OSTI)

We review the topic of Cosmic Microwave Background Anisotropy measurements carried out by means of balloon-borne telescopes. After a short description of the experimental methodology, we outline the peculiar problems of these experiments, and we describe the main results obtained and the perspects for future developments.

P. de Bernardis; S. Masi

1998-04-14T23:59:59.000Z

89

Future Cosmic Microwave Background Experiments  

E-Print Network (OSTI)

We summarise some aspects of experiments currently being built or planned, and indulge in wild speculation about possibilities on the more distant horizon.

Mark Halpern; Douglas Scott

1999-04-19T23:59:59.000Z

90

CMB power spectrum contribution from cosmic strings using field-evolution simulations of the Abelian Higgs model  

E-Print Network (OSTI)

We present the first field-theoretic calculations of the contribution made by cosmic strings to the temperature power spectrum of the cosmic microwave background (CMB). Unlike previous work, in which strings were modeled as idealized one-dimensional objects, we evolve the simplest example of an underlying field theory containing local U(1) strings, the Abelian Higgs model. Limitations imposed by finite computational volumes are overcome using the scaling property of string networks and a further extrapolation related to the lessening of the string width in comoving coordinates. The strings and their decay products, which are automatically included in the field theory approach, source metric perturbations via their energy-momentum tensor, the unequal-time correlation functions of which are used as input into the CMB calculation phase. These calculations involve the use of a modified version of CMBEASY, with results provided over the full range of relevant scales. We find that the string tension $\\mu$ required to normalize to the WMAP 3-year data at multipole $\\ell = 10$ is $G\\mu = [2.04\\pm0.06\\textrm{(stat.)}\\pm0.12\\textrm{(sys.)}] \\times 10^{-6}$, where we have quoted statistical and systematic errors separately, and $G$ is Newton's constant. This is a factor 2-3 higher than values in current circulation.

Neil Bevis; Mark Hindmarsh; Martin Kunz; Jon Urrestilla

2006-04-30T23:59:59.000Z

91

A LEKID-based CMB instrument design for large-scale observations in Greenland  

E-Print Network (OSTI)

We present the results of a feasibility study, which examined deployment of a ground-based millimeter-wave polarimeter, tailored for observing the cosmic microwave background (CMB), to Isi Station in Greenland. The instrument for this study is based on lumped-element kinetic inductance detectors (LEKIDs) and an F/2.4 catoptric, crossed-Dragone telescope with a 500 mm aperture. The telescope is mounted inside the receiver and cooled to $refrigerator to reduce background loading on the detectors. Linearly polarized signals from the sky are modulated with a metal-mesh half-wave plate that is rotated at the aperture stop of the telescope with a hollow-shaft motor based on a superconducting magnetic bearing. The modular detector array design includes at least 2300 LEKIDs, and it can be configured for spectral bands centered on 150~GHz or greater. Our study considered configurations for observing in spectral bands centered on 150, 210 and 267~GHz. The entire polarimeter is mounte...

Araujo, D C; Bond, J R; Bradford, K J; Chapman, D; Che, G; Day, P K; Didier, J; Doyle, S; Eriksen, H K; Flanigan, D; Groppi, C E; Hillbrand, S N; Johnson, B R; Jones, G; Limon, M; Miller, A D; Mauskopf, P; McCarrick, H; Mroczkowski, T; Reichborn-Kjennerud, B; Smiley, B; Sobrin, J; Wehus, I K; Zmuidzinas, J

2014-01-01T23:59:59.000Z

92

The BOOMERANG North America Instrument: A Balloon-borne Bolometric Radiometer Optimized for Measurements of Cosmic Background Radiation Anisotropies from 03 to 4°  

Science Journals Connector (OSTI)

We describe the BOOMERANG North America instrument, a balloon-borne bolometric radiometer designed to map the cosmic microwave background (CMB) radiation with 03 resolution over a significant portion of the sky. This receiver employs new technologies in bolometers, readout electronics, millimeter-wave optics and filters, cryogenics, scan, and attitude reconstruction. All these subsystems are described in detail in this paper. The system has been fully calibrated in flight using a variety of techniques, which are described and compared. Using this system, we have obtained a measurement of the first peak in the CMB angular power spectrum in a single, few hour long balloon flight. The instrument described here was a prototype of the BOOMERANG Long Duration Balloon experiment.

F. Piacentini; P. A. R. Ade; R. S. Bhatia; J. J. Bock; A. Boscaleri; P. Cardoni; B. P. Crill; P. de Bernardis; H. Del Castillo; G. De Troia; P. Farese; M. Giacometti; E. F. Hivon; V. V. Hristov; A. Iacoangeli; A. E. Lange; S. Masi; P. D. Mauskopf; L. Miglio; C. B. Netterfield; P. Palangio; E. Pascale; A. Raccanelli; S. Rao; G. Romeo; J. Ruhl; F. Scaramuzzi

2002-01-01T23:59:59.000Z

93

Mapping the CMB Sky: The BOOMERANG experiment  

E-Print Network (OSTI)

We describe the BOOMERanG experiment, a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment has been optimized for a long duration (7 to 14 days) flight circumnavigating Antarctica at the end of 1998. A test flight was performed on Aug.30, 1997 in Texas. The level of performance achieved in the test flight was satisfactory and compatible with the requirements for the long duration flight.

P. de Bernardis; P. A. R. Ade; R. Artusa; J. J. Bock; A. Boscaleri; B. P. Crill; G. De Troia; P. C. Farese; M. Giacommetti; V. V. Hristov; A. Iacoangeli; A. E. Lange; A. T. Lee; S. Masi; L. Martinis; P. V. Mason; P. D. Mauskopf; F. Melchiorri; L. Miglio; T. Montroy; C. B. Netterfield; E. Pascale; F. Piacentini; P. L. Richards; J. E. Ruhl; F. Scaramuzzi

1999-11-24T23:59:59.000Z

94

Delayed MeV-GeV Gamma-Ray Photons in Gamma-Ray Bursts: An Effect of Electromagnetic Cascades of Very High Energy Gamma Rays in the Infrared/Microwave Background  

Science Journals Connector (OSTI)

We show that the electromagnetic cascade of very high energy gamma-rays from gamma-ray bursts in the IR/microwave background will produce delayed MeV-GeV photons. Monte Carlo simulations have been performed to study this process. The distance of GB 940217 is estimated to be not less than 120 Mpc using our model, which supports a cosmological origin for this source. We also show that the time delays of gamma-ray photons are inversely proportional to their energy. Our model does not require the presence of intergalactic magnetic fields.

L. X. Cheng; K.

1996-01-01T23:59:59.000Z

95

NINE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: FINAL MAPS AND RESULTS  

SciTech Connect

We present the final nine-year maps and basic results from the Wilkinson Microwave Anisotropy Probe (WMAP) mission. The full nine-year analysis of the time-ordered data provides updated characterizations and calibrations of the experiment. We also provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are examined to separate cosmic microwave background (CMB) anisotropy from foreground emission, and both types of signals are analyzed in detail. We provide new point source catalogs as well as new diffuse and point source foreground masks. An updated template-removal process is used for cosmological analysis; new foreground fits are performed, and new foreground-reduced CMB maps are presented. We now implement an optimal C {sup –1} weighting to compute the temperature angular power spectrum. The WMAP mission has resulted in a highly constrained ?CDM cosmological model with precise and accurate parameters in agreement with a host of other cosmological measurements. When WMAP data are combined with finer scale CMB, baryon acoustic oscillation, and Hubble constant measurements, we find that big bang nucleosynthesis is well supported and there is no compelling evidence for a non-standard number of neutrino species (N {sub eff} = 3.84 ± 0.40). The model fit also implies that the age of the universe is t {sub 0} = 13.772 ± 0.059 Gyr, and the fit Hubble constant is H {sub 0} = 69.32 ± 0.80 km s{sup –1} Mpc{sup –1}. Inflation is also supported: the fluctuations are adiabatic, with Gaussian random phases; the detection of a deviation of the scalar spectral index from unity, reported earlier by the WMAP team, now has high statistical significance (n{sub s} = 0.9608 ± 0.0080); and the universe is close to flat/Euclidean (?{sub k} = -0.0027{sup +0.0039}{sub -0.0038}). Overall, the WMAP mission has resulted in a reduction of the cosmological parameter volume by a factor of 68,000 for the standard six-parameter ?CDM model, based on CMB data alone. For a model including tensors, the allowed seven-parameter volume has been reduced by a factor 117,000. Other cosmological observations are in accord with the CMB predictions, and the combined data reduces the cosmological parameter volume even further. With no significant anomalies and an adequate goodness of fit, the inflationary flat ?CDM model and its precise and accurate parameters rooted in WMAP data stands as the standard model of cosmology.

Bennett, C. L.; Larson, D.; Weiland, J. L. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Jarosik, N.; Page, L. [Department of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544-0708 (United States); Hinshaw, G.; Halpern, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Odegard, N.; Hill, R. S. [ADNET Systems, Inc., 7515 Mission Drive, Suite A100, Lanham, MD 20706 (United States); Smith, K. M. [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Gold, B. [School of Physics and Astronomy, University of Minnesota, 116 Church Street S.E., Minneapolis, MN 55455 (United States); Komatsu, E. [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild Str. 1, D-85741 Garching (Germany); Nolta, M. R. [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada); Spergel, D. N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544-1001 (United States); Wollack, E.; Kogut, A. [Code 665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Dunkley, J. [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Limon, M. [Columbia Astrophysics Laboratory, 550 West 120th Street, Mail Code 5247, New York, NY 10027-6902 (United States); Meyer, S. S. [Departments of Astrophysics and Physics, KICP and EFI, University of Chicago, Chicago, IL 60637 (United States); Tucker, G. S., E-mail: cbennett@jhu.edu [Department of Physics, Brown University, 182 Hope Street, Providence, RI 02912-1843 (United States); and others

2013-10-01T23:59:59.000Z

96

Recent CMB Results Ned Wright (UCLA)  

E-Print Network (OSTI)

Recent CMB Results by Ned Wright (UCLA) ·http://www.astro.ucla.edu/~wright/intro.html ·http://www.astro.ucla.edu/~wright/cosmolog.htm ·http://www.astro.ucla.edu/~wright/CMB-DT.html ·http://map.gsfc.nasa.gov #12;A Big Media Splash in 1992

Wright, Edward L. "Ned"

97

The Impact of the CMB on Large-Scale Structure  

E-Print Network (OSTI)

The COBE detection of microwave anisotropies provides the best way of fixing the amplitude of cosmological fluctuations on the largest scales. We discuss the impact of this new, precise normalization and give fitting formulae for the horizon-crossing amplitude as a function of \\Omega_0 and n for both open and flat cosmologies. We also discuss the relevant normalization (\\sigma_8) at galaxy-clustering scales. Already it is clear that the inferred \\sigma_8 can be unnaccepatably high for some of the simplest inflationary models, although many minor variants give an adequate fit. Generic topological defect models appear to fare rather badly, and it is unclear whether minor variants or improved calculations will help much. The detection and mapping of structure in the CMB anisotropy spectrum on smaller scales in the near future will enable us to achieve much stronger constraints on models.

Martin White; Douglas Scott

1996-01-30T23:59:59.000Z

98

Cosmological parameter estimation: impact of CMB aberration  

SciTech Connect

The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, i.e. aberration, and a shift in their frequency, i.e. Doppler effect. Both effects distort the temperature multipoles a{sub lm}'s via a mixing matrix at any l. The common lore when performing a CMB based cosmological parameter estimation is to consider that Doppler affects only the l = 1 multipole, and neglect any other corrections. In this paper we reconsider the validity of this assumption, showing that it is actually not robust when sky cuts are included to model CMB foreground contaminations. Assuming a simple fiducial cosmological model with five parameters, we simulated CMB temperature maps of the sky in a WMAP-like and in a Planck-like experiment and added aberration and Doppler effects to the maps. We then analyzed with a MCMC in a Bayesian framework the maps with and without aberration and Doppler effects in order to assess the ability of reconstructing the parameters of the fiducial model. We find that, depending on the specific realization of the simulated data, the parameters can be biased up to one standard deviation for WMAP and almost two standard deviations for Planck. Therefore we conclude that in general it is not a solid assumption to neglect aberration in a CMB based cosmological parameter estimation.

Catena, Riccardo [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Notari, Alessio, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: notari@ffn.ub.es [Departament de Física Fondamental i Institut de Ciéncies del Cosmos, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona (Spain)

2013-04-01T23:59:59.000Z

99

Microwave Quantum Illumination  

E-Print Network (OSTI)

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a system for applying this technique at microwave frequencies, a more appropriate spectral region for target detection than the optical, due to the naturally-occurring bright thermal background in the microwave regime. We use an electro-optomechanical converter to entangle microwave signal and optical idler fields, with the former being sent to probe the target region and the latter being retained at the source. The microwave radiation collected from the target region is then phase conjugated and upconverted into an optical field that is combined with the retained idler in a joint-detection quantum measurement. The error probability of this microwave quantum-illumination system, or 'quantum radar', is shown to be superior to that of any classical microwave radar of equal transmitted energy.

Shabir Barzanjeh; Saikat Guha; Christian Weedbrook; David Vitali; Jeffrey H. Shapiro; Stefano Pirandola

2014-10-15T23:59:59.000Z

100

Microwave Quantum Illumination  

E-Print Network (OSTI)

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a system for applying this technique at microwave frequencies, a more appropriate spectral region for target detection than the optical, due to the naturally-occurring bright thermal background in the microwave regime. We use an electro-optomechanical converter to entangle microwave signal and optical idler fields, with the former being sent to probe the target region and the latter being retained at the source. The microwave radiation collected from the target region is then phase conjugated and upconverted into an optical field that is combined with the retained idler in a joint-detection quantum measurement. The error probability of this microwave quantum-illumination system, or 'quantum radar', is shown to be superior to that of any classical microwave radar of equal transmit...

Barzanjeh, Shabir; Weedbrook, Christian; Vitali, David; Shapiro, Jeffrey H; Pirandola, Stefano

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Calibrating CMB Polarization Telescopes S. T. Staggs  

E-Print Network (OSTI)

parameters have units of intensity/c, where c is the speed of light. Because the CMB is observed and the Enrico Fermi Institute, University of Chicago, Chicago, IL, 60637 Abstract. Instruments for measuring in measuring this elusive polarized signal, and a suite of highly sensitive polarimeters are now being used

102

The microwave background anisotropies:?Observations  

Science Journals Connector (OSTI)

...imposes limits on energy-producing processes...modes, so more energy can be collected...CMBR source. The disadvantages of bolometeric detectors...course, the main advantage of interferometer...demonstrated the many advantages of using experiments...and 106 GHz. The solar panels (shown deployed...

David Wilkinson

1998-01-01T23:59:59.000Z

103

Cosmic Microwave Background Theory J. Richard Bond  

E-Print Network (OSTI)

\\Omega tot , but theoretical forecasts of fu­ ture long duration balloon and satellite experi­ ments gas processes can obscure the direct con­ nection to the early universe physics. Most easily inter

Bond, Dick

104

Hybrid Estimation of CMB Polarization Power Spectra  

E-Print Network (OSTI)

This paper generalises the hybrid power spectrum estimator developed in Efstathiou (2004a) to the estimation of polarization power spectra of the cosmic microwave background radiation. The hybrid power spectrum estimator is unbiased and we show that it is close to optimal at all multipoles, provided the pixel noise satisfies certain reasonable constraints. Furthermore, the hybrid estimator is computationally fast and can easily be incorporated in a Monte-Carlo chain for Planck-sized data sets. Simple formulae are given for the covariance matrices, including instrumental noise, and these are tested extensively against numerical simulations. We compare the behaviour of simple pseudo-Cell estimates with maximum likelihood estimates at low multipoles. For realistic sky cuts, maximum likelihood estimates reduce very significantly the mixing of E and B modes. To achieve limits on the scalar-tensor ratio of r<<0.1 from sky maps with realistic sky cuts, maximum likelihood methods, or pseudo-Cell estimators based on unambiguous E and B modes, will be essential.

G. Efstathiou

2006-01-05T23:59:59.000Z

105

The impact of non-Planckian effects on radio cosmological backgrounds  

E-Print Network (OSTI)

Non-Planckian (NP) spectral modifications of the CMB radiation spectrum can be produced due to the existence of a non-zero value of the plasma frequency at the recombination epoch. We present here an analysis of NP effects on the radio cosmological background and we derive, for the first time, predictions of their amplitude on three different observables: the CMB spectrum, the Sunyaev-Zel'dovich (SZ) effect in cosmic structures, and the 21-cm background temperature brightness change. We find that NP effect can manifest in the CMB spectrum at $\

Colafrancesco, Sergio; Marchegiani, Paolo

2015-01-01T23:59:59.000Z

106

Microwave generator  

DOE Patents (OSTI)

A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit there through effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators. 6 figs.

Kwan, T.J.T.; Snell, C.M.

1987-03-31T23:59:59.000Z

107

Microwave furnace having microwave compatible dilatometer  

DOE Patents (OSTI)

An apparatus for measuring and monitoring a change in the dimension of a sample being heated by microwave energy is described. The apparatus comprises a microwave heating device for heating a sample by microwave energy, a microwave compatible dilatometer for measuring and monitoring a change in the dimension of the sample being heated by microwave energy without leaking microwaves out of the microwave heating device, and a temperature determination device for measuring and monitoring the temperature of the sample being heated by microwave energy. 2 figs.

Kimrey, H.D. Jr.; Janney, M.A.; Ferber, M.K.

1992-03-24T23:59:59.000Z

108

Microwave furnace having microwave compatible dilatometer  

DOE Patents (OSTI)

An apparatus for measuring and monitoring a change in the dimension of a sample being heated by microwave energy is described. The apparatus comprises a microwave heating device for heating a sample by microwave energy, a microwave compatible dilatometer for measuring and monitoring a change in the dimension of the sample being heated by microwave energy without leaking microwaves out of the microwave heating device, and a temperature determination device for measuring and monitoring the temperature of the sample being heated by microwave energy.

Kimrey, Jr., Harold D. (Knoxville, TN); Janney, Mark A. (Knoxville, TN); Ferber, Mattison K. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

109

A perspective on the CMB acoustic peak  

E-Print Network (OSTI)

CMB angular spectrum measurements suggest a flat universe. This paper clarifies the relation between geometry and the spherical harmonic index of the first acoustic peak ($\\ell_{peak}$). Numerical and analytic calculations show that $\\ell_{peak}$ is approximately a function of $\\Omega_K/\\Omega_M$ where $\\Omega_K$ and $\\Omega_M$ are the curvature ($\\Omega_K > 0$ implies an open geometry) and mass density today in units of critical density. Assuming $\\Omega_K/\\Omega_M \\ll 1$, one obtains a simple formula for $\\ell_{peak}$, the derivation of which gives another perspective on the widely-recognized $\\Omega_M$-$\\Omega_\\Lambda$ degeneracy in flat models. This formula for near-flat cosmogonies together with current angular spectrum data yields familiar parameter constraints.

T. A. Marriage

2002-03-11T23:59:59.000Z

110

Signature of cosmic string wakes in the CMB polarization  

SciTech Connect

We calculate a signature of cosmic strings in the polarization of the cosmic microwave background. We find that ionization in the wakes behind moving strings gives rise to extra polarization in a set of rectangular patches in the sky whose length distribution is scale-invariant. The length of an individual patch is set by the comoving Hubble radius at the time the string is perturbing the cosmic microwave background. The polarization signal is largest for string wakes produced at the earliest post-recombination time, and for an alignment in which the photons cross the wake close to the time the wake is created. The maximal amplitude of the polarization relative to the temperature quadrupole is set by the overdensity of free electrons inside a wake which depends on the ionization fraction f inside the wake. For a cosmic string wake coming from an idealized string segment, the signal can be as high as 0.06 {mu}K in degree scale polarization for a string at high redshift (near recombination) and a string tension {mu} given by G{mu}=10{sup -7}.

Danos, Rebecca J.; Brandenberger, Robert H.; Holder, Gil [Department of Physics, McGill University, Montreal, QC, H3A 2T8 (Canada)

2010-07-15T23:59:59.000Z

111

Legal Background  

Office of Legacy Management (LM)

Legal Background Legal Background Book 1 . . Project Rulison :.Contract: . . AEC, Austral Oil Company, and CER Geonuclear Corporation, . . . . , . . . . , . . February 1969 DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. PROJECT RULISON CONTRACT NO. UNITED STATES OF AMERICA REPRESENTED BY THE ATOMIC ENERGY COMMISSION and THE DEPARTMENT. OF THE INTERIOR and AUSTRAL OIL COMPANY INCORPORATED and CER GEONUCLEAR CORPORATION Prepared by OFFICE OF THE CHIEF COUNSEL NEVADA OPERATIONS OFFICE FEBRUARY 1969 This page intentionally left blank UNITED STATES ATOMIC ENERGY COMMISSION . NEVADA OPERATIONS OFFICE TABLE OF CONTENTS VII VIII XV XVI XVII SUBJECT - PAGE Definitions 2 Description of Project ~ulisdn 3

112

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network (OSTI)

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanie...

Fuller, George M; Kusenko, Alexander

2011-01-01T23:59:59.000Z

113

The 2dF Galaxy Redshift Survey: The amplitudes of fluctuations in the 2dFGRS and the CMB, and implications for galaxy biasing  

E-Print Network (OSTI)

We compare the amplitudes of fluctuations probed by the 2dF Galaxy Redshift Survey and by the latest measurements of the Cosmic Microwave Background anisotropies. By combining the 2dFGRS and CMB data we find the linear-theory rms mass fluctuations in 8 Mpc/h spheres to be sigma_8 = 0.73 +-0.05 (after marginalization over the matter density parameter Omega_m and three other free parameters). This normalization is lower than the COBE normalization and previous estimates from cluster abundance, but it is in agreement with some revised cluster abundance determinations. We also estimate the scale-independent bias parameter of present-epoch L_s = 1.9L_* APM-selected galaxies to be b(L_s,z=0) = 1.10 +- 0.08 on comoving scales of 0.02 < k < 0.15 h/Mpc. If luminosity segregation operates on these scales, L_* galaxies would be almost un-biased, b(L_*,z=0) = 0.96. These results are derived by assuming a flat Lambda-CDM Universe, and by marginalizing over other free parameters and fixing the spectral index n=1 and the optical depth due to reionization tau=0. We also study the best fit pair (Omega_m,b), and the robustness of the results to varying n and tau. Various modelling corrections can each change the resulting b by 5-15 per cent. The results are compared with other independent measurements from the 2dFGRS itself, and from the SDSS, cluster abundance and cosmic shear.

Ofer Lahav; Sarah L. Bridle; Will J. Percival; John A. Peacock; George Efstathiou; Carlton M. Baugh; Joss Bland-Hawthorn; Terry Bridges; Russell Cannon; Shaun Cole; Matthew Colless; Chris Collins; Warrick Couch; Gavin Dalton; Roberto De Propris; Simon P. Driver; Richard S. Ellis; Carlos S. Frenk; Karl Glazebrook; Carole Jackson; Ian Lewis; Stuart Lumsden; Steve Maddox; Darren S. Madgwick; Stephen Moody; Peder Norberg; Bruce A. Peterson; Will Sutherland; Keith Taylor

2002-05-19T23:59:59.000Z

114

CMB constraints on light dark matter candidates  

E-Print Network (OSTI)

Unveiling the nature of cosmic dark matter is an urgent issue in cosmology. Here we make use of a strategy based on the search for the imprints left on the CMB temperature and polarization spectra by the energy deposition due to annihilations of the most promising dark matter candidate, a stable WIMP of mass 1-20 GeV. A major improvement with respect to previous similar studies is a detailed treatment of the annihilation cascade and its energy deposition in the cosmic gas. This is vital as this quantity is degenerate with the annihilation cross-section . The strongest constraints are obtained from Monte Carlo Markov Chains analysis of the combined WMAP7 and SPT datasets up to lmax = 3100. If annihilation occurs via the e+e- channel, a light WIMP can be excluded at 2-{\\sigma} c.l. as a viable DM candidate in the above mass range. However, if annihilation occurs via {\\mu}+{\\mu}- or {\\tau}+{\\tau}- channels instead we find that WIMPs with mass > 5 GeV might represent a viable cosmological DM candidate. We compare...

Evoli, Carmelo; Ferrara, Andrea

2012-01-01T23:59:59.000Z

115

Anisotropy in the Microwave Sky: Results from the First Flight of BAM  

E-Print Network (OSTI)

Results are reported from the first flight of a new balloon-borne instrument, BAM (Balloon-borne Anisotropy Measurement), designed to search for cosmic microwave background (CMB) anisotropy. The instrument uses a cryogenic differential Fourier transform spectrometer to obtain data in five spectral channels whose central frequencies lie in the range 3.7 cm^{-1} to 8.5 cm^{-1}. The spectrometer is coupled to an off-axis prime focus telescope; the combination yields difference spectra of two regions on the sky defined by 0\\fdg 7 FWHM beams separated by 3\\fdg 6. Single differences obtained at ten sky positions show statistically significant fluctuations. Assuming Gaussian correlated anisotropy, for the band average 3.1 cm^{-1} to 9.2 cm^{-1}, one finds $\\Delta T/T = 3.1^{+3.1}_{1.1}\\times 10^{-5}$ (90% confidence interval) for a correlation angle of 1\\fdg 2. This corresponds to $Q_{flat} = 35.9^{17.7}_{6.3} \\mu K$ (1\\sigma).

G. S. Tucker; H. P. Gush; M. Halpern; I. Shinkoda; W. Towlson

1996-11-27T23:59:59.000Z

116

Measuring dark energy clustering with CMB-galaxy correlations  

Science Journals Connector (OSTI)

The integrated Sachs-Wolfe effect in the cosmic microwave background as measured through its correlation with galaxies provides a unique opportunity to study the dynamics of the dark energy through its large scale clustering properties. Ultimately, a deep all-sky galaxy survey out to z?2 can make a ?10? or ?10% measurement of the correlation and limit ?3% changes in the gravitational potential or total density fluctuation due to dark energy clustering on the Gpc scale. A canonical single scalar field or quintessence model predicts that these clustering effects will appear on the horizon scale with a strength that reflects the evolution of the dark energy density. In terms of a constant equation of state, this would allow tests of the quintessence prediction for models where |1+w|?0.05.

Wayne Hu and Ryan Scranton

2004-12-06T23:59:59.000Z

117

CMVRTC: Background  

NLE Websites -- All DOE Office Websites (Extended Search)

newsletters newsletters contacts tools latest news 12.05.2013 Next Quarterly meeting scheduled for February 19, 2014 (10 a.m. - 12 p.m. ET). read more ... More information CMVRTC Showcase Events CMVRTC Poster Sessions Related Projects Heavy Truck Duty Cycle Medium Truck Duty Cycle Fuel Tax Evasion Other technical director For more information, please contact Gary Capps, Technical Director, at cappsgj@ornl.gov or (865) 946-1285. Background Introduction Vision cmvrtc poster Benefits Technology Transfer Introduction The Federal Motor Carrier Safety Administration (FMCSA) launched the Commercial Motor Vehicle Roadside Technology Corridor (CMVRTC) on August 7, 2007, in partnership with the Tennessee Departments of Safety and Transportation, the Oak Ridge National Laboratory (ORNL), and the

118

The Cosmic Background Imager  

E-Print Network (OSTI)

Design and performance details are given for the Cosmic Background Imager (CBI), an interferometer array that is measuring the power spectrum of fluctuations in the cosmic microwave background radiation (CMBR) for multipoles in the range 400 < l < 3500. The CBI is located at an altitude of 5000 m in the Atacama Desert in northern Chile. It is a planar synthesis array with 13 0.9-m diameter antennas on a 6-m diameter tracking platform. Each antenna has a cooled, low-noise receiver operating in the 26-36 GHz band. Signals are cross-correlated in an analog filterbank correlator with ten 1 GHz bands. This allows spectral index measurements which can be used to distinguish CMBR signals from diffuse galactic foregrounds. A 1.2 kHz 180-deg phase switching scheme is used to reject cross-talk and low-frequency pick-up in the signal processing system. The CBI has a 3-axis mount which allows the tracking platform to be rotated about the optical axis, providing improved (u,v) coverage and a powerful discriminant against false signals generated in the receiving electronics. Rotating the tracking platform also permits polarization measurements when some of the antennas are configured for the orthogonal polarization.

S. Padin; M. C. Shepherd; J. K. Cartwright; R. G. Keeney; B. S. Mason; T. J. Pearson; A. C. S. Readhead; W. L. Schaal; J. Sievers; P. S. Udomprasert; J. K. Yamasaki; W. L. Holzapfel; J. E. Carlstrom; M. Joy; S. T. Myers; A. Otarola

2001-10-05T23:59:59.000Z

119

Quantum Illumination at the Microwave Wavelengths  

E-Print Network (OSTI)

Quantum illumination is a quantum-optical sensing technique in which an entangled source is exploited to improve the detection of a low-reflectivity object that is immersed in a bright thermal background. Here we describe and analyze a system for applying this technique at microwave frequencies, a more appropriate spectral region for target detection than the optical, due to the naturally-occurring bright thermal background in the microwave regime. We use an electro-optomechanical converter to entangle microwave signal and optical idler fields, with the former being sent to probe the target region and the latter being retained at the source. The microwave radiation collected from the target region is then phase conjugated and upconverted into an optical field that is combined with the retained idler in a joint-detection quantum measurement. The error probability of this microwave quantum-illumination system, or quantum radar, is shown to be superior to that of any classical microwave radar of equal transmitted energy.

Shabir Barzanjeh; Saikat Guha; Christian Weedbrook; David Vitali; Jeffrey H. Shapiro; Stefano Pirandola

2015-01-31T23:59:59.000Z

120

Gun Injection into a Microwave Plasma J. C. Sprott  

E-Print Network (OSTI)

Gun Injection into a Microwave Plasma by J. C. Sprott May, 1970 Plasma Studies University high densities by rapid pulsed gun injection. TIlis no te describes measurements made -Cwo years ago in which a gun plasma was injected into a background microwave plasma of variable density in the toroidal

Sprott, Julien Clinton

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Heavy sterile neutrinos, entropy and relativistic energy production, and the relic neutrino background  

E-Print Network (OSTI)

We explore the implications of the existence of heavy neutral fermions (i.e., sterile neutrinos) for the thermal history of the early universe. In particular, we consider sterile neutrinos with rest masses in the 100 MeV to 500 MeV range, with couplings to ordinary active neutrinos large enough to guarantee thermal and chemical equilibrium at epochs in the early universe with temperatures T > 1 GeV, but in a range to give decay lifetimes from seconds to minutes. Such neutrinos would decouple early, with relic densities comparable to those of photons, but decay out of equilibrium, with consequent prodigious entropy generation prior to, or during, Big Bang Nucleosynthesis (BBN). Most of the ranges of sterile neutrino rest mass and lifetime considered are at odds with Cosmic Microwave Background (CMB) limits on the relativistic particle contribution to energy density (e.g., as parameterized by N_eff). However, some sterile neutrino parameters can lead to an acceptable N_eff. These parameter ranges are accompanied by considerable dilution of the ordinary background relic neutrinos, possibly an adverse effect on BBN, but sometimes fall in a range which can explain measured neutrino masses in some particle physics models. A robust signature of these sterile neutrinos would be a measured N_eff not equal to 3 coupled with no cosmological signal for neutrino rest mass when the detection thresholds for these probes are below laboratory-established neutrino mass values, either as established by the atmospheric neutrino oscillation scale or direct measurements with, e.g., KATRIN or neutrino-less double beta decay experiments.

George M. Fuller; Chad T. Kishimoto; Alexander Kusenko

2011-10-28T23:59:59.000Z

122

Microwave Radiometer (MWR) Handbook  

SciTech Connect

The Microwave Radiometer (MWR) provides time-series measurements of column-integrated amounts of water vapor and liquid water. The instrument itself is essentially a sensitive microwave receiver. That is, it is tuned to measure the microwave emissions of the vapor and liquid water molecules in the atmosphere at specific frequencies.

Morris, VR

2006-08-01T23:59:59.000Z

123

Using White Dish CMB Anisotropy Data to Probe Open and Flat-Lambda CDM Cosmogonies  

E-Print Network (OSTI)

We use data from the White Dish experiment to set limits on cosmic microwave background radiation anisotropies in open and spatially-flat-Lambda cold dark matter cosmogonies. We account for the White Dish calibration uncertainty, and marginalize over the offset and gradient removed from the data. Our 2-sigma upper limits are larger than those derived previously. These upper limits are consistent with those derived from the $COBE$-DMR data for all models tested.

B. Ratra; K. Ganga; N. Sugiyama; G. S. Tucker; G. S. Griffin; H. T. Nguyen; J. B. Peterson

1997-10-24T23:59:59.000Z

124

A Modified chi^2-Test for CMB Analyses  

E-Print Network (OSTI)

We present a new general procedure for determining a given set of quantities. To this end, we define certain statistic, that we call 'modified $\\chi^2$' ($\\chi^2_M$), because of its similarity with the standard $\\chi^2$. The terms of this $\\chi^2_M$ are made up of the fluctuations of an unbiased estimator of some statistical quantities, and certain weights. Only the diagonal terms of the covariance matrix explicitly appear in our statistic, while the full covariance matrix (and not its inverse) is implicitly included in the calculation of the weights. Choosing these weights we may obtain, through minimising the $\\chi^2_M$, the estimator that provides the minimum RMS, either for those quantities or for the parameters on which these quantities depend. In this paper, we describe our method in the context of Cosmic Microwave Background experiments, in order to obtain either the statistical properties of the maps, or the cosmological parameters. The test here is constructed out of some estimator of the two-point correlation function at different angles. For the problem of one parameter estimation, we show that our method has the same power as the maximum likelihood method. We have also applied this method to Monte Carlo simulations of the COBE-DMR data, as well as to the actual 4-year data, obtaining consistent results with previous analyses. We also provide a very good analytical approximation to the distribution function of our statistic, which could also be useful in other contexts.

J. A. Rubino-Martin; J. Betancort-Rijo

2003-07-01T23:59:59.000Z

125

Efficient power spectrum estimation for high resolution CMB maps  

SciTech Connect

Estimation of the angular power spectrum of the cosmic microwave background on a small patch of sky is usually plagued by serious spectral leakage, especially when the map has a hard edge. Even on a full-sky map, point source masks can alias power from large scales to small scales producing excess variance at high multipoles. We describe a new fast, simple, and local method for estimation of power spectra on small patches of the sky that minimizes spectral leakage and reduces the variance of the spectral estimate. For example, when compared with the standard uniform sampling approach on a 8 deg. x 8 deg. patch of the sky with 2% area masked due to point sources, our estimator halves the error bars at l=2000 and achieves a more than fourfold reduction in error bars at l=3500. Thus, a properly analyzed experiment will have error bars at l=3500 equivalent to those of an experiment analyzed with the now standard technique with {approx}16-25 times the integration time.

Das, Sudeep; Hajian, Amir; Spergel, David N. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States)

2009-04-15T23:59:59.000Z

126

Reconstructing the primordial power spectrum from the CMB  

SciTech Connect

We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial cosmological perturbations are adiabatic, we present a function space generalization of the usual Fisher matrix formalism applied to a CMB experiment resembling Planck with and without ancillary data. This work is closely related to other work on recovering the inflationary potential and exploring specific models of non-minimal, or perhaps baroque, primordial power spectra. The approach adopted here, however, most directly expresses what the data is really telling us. We explore in detail the structure of the available information and quantify exactly what features can be reconstructed and at what statistical significance.

Gauthier, Christopher; Bucher, Martin, E-mail: cgauthie@apc.univ-paris7.fr, E-mail: bucher@apc.univ-paris7.fr [Laboratoire APC, Université Paris Diderot, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

2012-10-01T23:59:59.000Z

127

Cosmological birefringence constraints from CMB and astrophysical polarization data  

E-Print Network (OSTI)

Cosmological birefringence is a rotation of the polarization plane of photons coming from sources of astrophysical and cosmological origin. The rotation can also depend on the energy of the photons and not only on the distance of the source and on the cosmological evolution of the underlying theoretical model. In this work, we constrain few selected models for cosmological birefringence, combining CMB and astrophysical data at radio, optical, X and gamma wavelengths, taking into account the specific energy and distance dependences.

Galaverni, M; Paci, F; Finelli, F

2014-01-01T23:59:59.000Z

128

Graphene Integrated Microwave Photonics  

Science Journals Connector (OSTI)

This paper proposes and analyzes the incorporation of graphene to integrated waveguides and circuits for application to the field of microwave photonics (MWP). We discuss the main...

Capmany, José; Doménech, David; Muñoz, Pascual

2014-01-01T23:59:59.000Z

129

Higher-order gravitational perturbations of the cosmic microwave background  

Science Journals Connector (OSTI)

We study the behavior of light rays in perturbed Robertson-Walker cosmologies, calculating the redshift between an observer and the surface of last scattering to second order in the metric perturbation. At first order we recover the classic results of Sachs and Wolfe, and at second order we delineate the various new effects which appear; there is no a priori guarantee that these effects are significantly smaller than those at first order, since there are large length scales in the problem which could lead to sizable prefactors. We find that secondorder terms of potential observational interest may be interpreted as transverse and longitudinal lensing by foreground density perturbations, and a correction to the integrated Sachs-Wolfe effect.

Ted Pyne and Sean M. Carroll

1996-03-15T23:59:59.000Z

130

Higher-Order Gravitational Perturbations of the Cosmic Microwave Background  

E-Print Network (OSTI)

We study the behavior of light rays in perturbed Robertson-Walker cosmologies, calculating the redshift between an observer and the surface of last scattering to second order in the metric perturbation. At first order we recover the classic results of Sachs and Wolfe, and at second order we delineate the various new effects which appear; there is no {\\it a priori} guarantee that these effects are significantly smaller than those at first order, since there are large length scales in the problem which could lead to sizable prefactors. We find that second order terms of potential observational interest may be interpreted as transverse and longitudinal lensing by foreground density perturbations, and a correction to the integrated Sachs-Wolfe effect.

Ted Pyne; Sean M. Carroll

1995-12-07T23:59:59.000Z

131

NEAR-MILLIMETER SPECTRUM OF THE MICROWAVE BACKGROUND  

E-Print Network (OSTI)

terminated at time B. Thermometers T1 through T7 are locatedindicated in Fig. 1. The thermometer T8 , which was immersedand a heater. A separate thermometer was used to monitor the

Woody, D.P.

2013-01-01T23:59:59.000Z

132

Variable frequency microwave heating apparatus  

DOE Patents (OSTI)

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

133

Microwave Observation of Detonation  

Science Journals Connector (OSTI)

... We have recently developed a technique for measuring the velocity of detonation of various high explosives under contained conditions by means of the reflexion of microwaves from ... contained conditions by means of the reflexion of microwaves from a region travelling with the detonation front. The technique differs substantially from that of Koch2 and the recent development of ...

JOHN L. FARRANDS; G. F. CAWSEY

1956-01-07T23:59:59.000Z

134

Microwave processing of ceramics  

SciTech Connect

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-04-01T23:59:59.000Z

135

Microwave processing of ceramics  

SciTech Connect

Recent work in the areas of microwave processing and joining of ceramics is briefly reviewed. Advantages and disadvantages of microwave processing as well as some of the current issues in the field are discussed. Current state and potential for future commercialization of this technology is also addressed.

Katz, J.D.

1993-01-01T23:59:59.000Z

136

ARM - Campaign Backgrounders  

NLE Websites -- All DOE Office Websites (Extended Search)

Annual Reports Program Fact Sheets Campaign Backgrounders Education and Outreach Posters Brochures Research Highlights Summaries Campaign Backgrounders Please contact...

137

Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources  

E-Print Network (OSTI)

Almost the totality of the bright foreground sources in the WMAP CMB maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope $\\alpha_{mu x}$ of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Sychrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately $10^{-15}$ erg/s would be crucial to locate and remove over 100,000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants.

P. Giommi; M. Capalbi; E. Cavazzuti; S. Colafrancesco; A. Cucchiara; A. Falcone; J. Kennea; R. Nesci; M. Perri; G. Tagliaferri; A. Tramacere; G. Tosti; A. J. Blustin; G. Branduardi-Raymont; D. N. Burrows; G. Chincarini; A. J. Dean; N. Gehrels; H. Krimm; F. Marshall; A. M. Parsons; B. Zhang

2007-03-07T23:59:59.000Z

138

Non-Gaussianity and CMB aberration and Doppler  

SciTech Connect

The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators f{sub NL}. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10{sup ?3} for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance ? for f{sub NL} both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating f{sub NL} it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

Catena, Riccardo [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Liguori, Michele; Renzi, Alessandro [INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Notari, Alessio, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: michele.liguori@pd.infn.it, E-mail: notari@ffn.ub.es, E-mail: arenzi@pd.infn.it [Departament de Física Fondamental i Institut de Ciéncies del Cosmos, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona (Spain)

2013-09-01T23:59:59.000Z

139

Cosmological Implications of the CMB Large-scale Structure  

E-Print Network (OSTI)

WMAP and Planck may have uncovered several anomalies in the full CMB sky that could indicate possible new physics driving the growth of density fluctuations in the early Universe. These include an unusually low power at the largest scales and an apparent alignment of the quadrupole and octopole moments. In LCDM, the quadrupole and octopole moments should be statistically independent. These low probability features may simply be due to posterior selections from many such possible effects. If this is not the case, however, their combined statistical significance would be equal to the product of their individual significances. Ignoring the biasing due to posterior selection, the missing large-angle correlations would have a probability as low as ~0.1% and the low-l multipole alignment would be unlikely at the ~4.9% level; under the least favourable conditions, their simultaneous observation in the context of the standard model could then be likely at only the ~0.005% level. In this paper, we explore the possibility that these features are indeed anomalous, and show that the corresponding probability of CMB multipole alignment in the R_h=ct Universe would then be ~7-10%, depending on the number of large-scale Sachs-Wolfe induced fluctuations. Since the low power at the largest spatial scales is reproduced in this cosmology without the need to invoke cosmic variance, the overall likelihood of observing both of these features in the CMB is > 7%, much more likely than in LCDM. The key physical ingredient responsible for this difference is the existence in the former of a maximum fluctuation size at the time of recombination, which is absent in the latter because of inflation.

Fulvio Melia

2014-09-27T23:59:59.000Z

140

Initial Tests for an Analog Continuum Correlator for CMB Interferometry Huan T. Tran  

E-Print Network (OSTI)

: Lyman Page Abstract We are proposing to build a high frequency interferometer to study the CMB;2 Initial Tests for an Analog Continuum Correlator for CMB Interferometry Huan T. Tran Abstract We-15) and work below 35 GHz and hence rely heavily on HEMT technology. We are in the initial planning stages

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While these samples are representative of the content of NLEBeta,
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141

Microwaves and Bacteria  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwaves and Bacteria Microwaves and Bacteria Name: mike Location: N/A Country: N/A Date: N/A Question: Do the microwaves in a microwave kill bacteria or is it the heat that kills the bacteria? I am wondering this because i have a science fair project and i am searching for a project dealing with bacteria. Replies: As far as I'm aware it is the heat that kill bacteria in a microwave, and they need quite some time to be dead. The spores that some kind of bacteria make to survive harsh conditions do not contain much water and they might survive microwaves. I'm not sure what bacteria do that can survive high dosis of radiation, like Deinococcus radiodurans. They can do this by a very efficient repair system for their DNA. My guess is that they would also be killed by the heat generated in a microwave but I haven't found any data on this.

142

Microwave coupler and method  

DOE Patents (OSTI)

The present invention is directed to a microwave coupler for enhancing the heating or metallurgical treatment of materials within a cold-wall, rapidly heated cavity as provided by a microwave furnace. The coupling material of the present invention is an alpha-rhombohedral-boron-derivative-structure material such as boron carbide or boron silicide which can be appropriately positioned as a susceptor within the furnace to heat other material or be in powder particulate form so that composites and structures of boron carbide such as cutting tools, grinding wheels and the like can be rapidly and efficiently formed within microwave furnaces.

Holcombe, C.E.

1984-11-29T23:59:59.000Z

143

Emitron: microwave diode  

DOE Patents (OSTI)

The invention comprises a new class of device, driven by electron or other charged particle flow, for producing coherent microwaves by utilizing the interaction of electromagnetic waves with electron flow in diodes not requiring an external magnetic field. Anode and cathode surfaces are electrically charged with respect to one another by electron flow, for example caused by a Marx bank voltage source or by other charged particle flow, for example by a high energy charged particle beam. This produces an electric field which stimulates an emitted electron beam to flow in the anode-cathode region. The emitted electrons are accelerated by the electric field and coherent microwaves are produced by the three dimensional spatial and temporal interaction of the accelerated electrons with geometrically allowed microwave modes which results in the bunching of the electrons and the pumping of at least one dominant microwave mode.

Craig, G.D.; Pettibone, J.S.; Drobot, A.T.

1982-05-06T23:59:59.000Z

144

COBE Data Spatial--Frequency Analysis and CMB Anisotropy Spectrum  

E-Print Network (OSTI)

We discuss the problem of CMB spectrum corruption during Galactic emission removing. A new technique of spatial--frequency data reduction is proposed. The technique gives us a possibility to avoid a spatial harmonics nonorthogonality. The proposed technique is applied to the two-year COBE DMR sky maps. We exclude the harmonics with l=7, 9,13, 23 and 25 as having anomalous statistics noise behavior. One shows that procedure do not give systematic errors, if the data are statistically regular. The spectral parameter of the power spectrum of primordial perturbation $n=1.84 \\pm 0.29$ and quadrupole moment $Q_2=15.22 \\pm 3.0$ are estimated. The power spectrum estimation results are inconsistent with the Harrison-Zel`dovich $n=1$ model with the confidence 99%. It is shown a necessity of an increasing a survey sensitivity to reach a more reliable estimation of the cosmological signal.

A. A. Brukhanov; D. P. Skulachev; I. A. Strukov; T. V. Konkina

1995-12-22T23:59:59.000Z

145

Microwave and Radio Frequency Workshop  

Energy.gov (U.S. Department of Energy (DOE))

At the Microwave and Radio Frequency Workshop (held in Long Beach, CA, on July 25, 2012), academic and industry experts discussed the existing and emerging electrotechnologies – such as microwave ...

146

Microwave | OpenEI  

Open Energy Info (EERE)

Microwave Microwave Dataset Summary Description The following data-set is for a benchmark residential home for all TMY3 locations across all utilities in the US. The data is indexed by utility service provider which is described by its "unique" EIA ID ( Source National Renewable Energy Laboratory Date Released April 05th, 2012 (2 years ago) Date Updated April 06th, 2012 (2 years ago) Keywords AC apartment CFL coffeemaker Computer cooling cost demand Dishwasher Dryer Furnace gas HVAC Incandescent Laptop load Microwave model NREL Residential television tmy3 URDB Data text/csv icon Residential Cost Data for Common Household Items (csv, 14.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL)

147

PHOTOCHEMISTRY IN THE MICROWAVE FIELD  

E-Print Network (OSTI)

. The objective of microwave-assisted photochemistry is frequently, but not irreplaceably, connected. EDLs Hg-EDLs: I2- and P-EDLs S-EDL vs. solar radiation flux Literature: 1. P. Kl�n V. C�rkva, Microwave in the MW field. � No evidence for nonthermal microwave effects was observed. Outlook � MW-assisted

Cirkva, Vladimir

148

CMB Anisotropies, Large-Scale Structure and the Future  

E-Print Network (OSTI)

We are now beginning to learn detailed information about cosmological parameters from the shapes of the matter and radiation power spectra, together with their relative normalization. As more high quality data are gathered from galaxy surveys and from microwave anisotropies, the range of allowed models is expected to get incrementally smaller. The amount of information potentially available from a high-resolution satellite experiment should allow a determination of essentially {\\it all} currently discussed cosmological parameters to less than ~10%.

Douglas Scott

1995-09-07T23:59:59.000Z

149

Variable frequency microwave furnace system  

DOE Patents (OSTI)

A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

150

Variable frequency microwave furnace system  

DOE Patents (OSTI)

A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

Bible, D.W.; Lauf, R.J.

1994-06-14T23:59:59.000Z

151

Extended Mosaic Observations with the Cosmic Background Imager  

E-Print Network (OSTI)

Two years of microwave background observations with the Cosmic Background Imager (CBI) have been combined to give a sensitive, high resolution angular power spectrum over the range 400 2000 power previously seen with the CBI is reduced. Under the assumption that any signal in excess of the primary anisotropy is due to a secondary Sunyaev-Zeldovich anisotropy in distant galaxy clusters we use CBI, ACBAR, and BIMA data to place a constraint on the present-day rms mass fluctuation sigma_8. We present the results of a cosmological parameter analysis on the l < 2000 primary anisotropy data which show significant improvements in the parameters as compared to WMAP alone, and we explore the role of the small-scale cosmic microwave background data in breaking parameter degeneracies.

A. C. S. Readhead; B. S. Mason; C. R. Contaldi; T. J. Pearson; J. R. Bond; S. T. Myers; S. Padin; J. L. Sievers; J. K. Cartwright; M. C. Shepherd; D. Pogosyan; S. Prunet; P. Altamirano; R. Bustos; L. Bronfman; S. Casassus; W. L. Holzapfel; J. May; U. -L. Pen; S. Torres; P. S. Udomprasert

2004-02-15T23:59:59.000Z

152

Development of Generic Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Kentucky Guidance for Ambient Background Assessment Kentucky Guidance for Ambient Background Assessment January 8, 2004 Natural Resources and Environmental Protection Cabinet Introduction This guidance document is intended to assist in comparing site data and background data for sites undergoing environmental assessment. These procedures provide a simplified statistical procedure for determining if the site data is part of the background population. It also provides generic statewide background values for inorganic chemicals that may be used in lieu of collecting site-specific background samples. The statistical procedures may be used for site- specific data or the generic statewide values in Tables 1 and 2. This guidance does not preclude other appropriate statistical comparisons from being made, but rather a simplified screening

153

Cosmic Background Radiation Mini-Review  

E-Print Network (OSTI)

This is a complete re-write of the mini-review for the Review of Particle Physics (a.k.a the Partcicle Data Book), which includes an assessment of the CMB anisotropy results and their interpretation up until the end of 2003. It forms a compact overview of the field at this time. Sections headings are: Introduction; Description of CMB Anisotropies; Cosmological Parameters; Physics of Anisotropies; Current Anisotropy Data; CMB Polarization; Complications; Constraints on Cosmologies; Particle Physics Constraints; Fundamental Lessons; and Future Directions.

Douglas Scott; George Smoot

2004-06-24T23:59:59.000Z

154

Polarization Observations with the Cosmic Background Imager  

E-Print Network (OSTI)

Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum. This key agreement between the phase of the observed polarization spectrum and that predicted based on the total intensity spectrum provides support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

A. C. S. Readhead; S. T. Myers; T. J. Pearson; J. L. Sievers; B. S. Mason; C. R. Contaldi; J. R. Bond; R. Bustos; P. Altamirano; C. Achermann; L. Bronfman; J. E. Carlstrom; J. K. Cartwright; S. Casassus; C. Dickinson; W. L. Holzapfel; J. M. Kovac; E. M. Leitch; J. May; S. Padin; D. Pogosyan; M. Pospieszalski; C. Pryke; R. Reeves; M. C. Shepherd; S. Torres

2004-09-23T23:59:59.000Z

155

ARM - Radar Backgrounder  

NLE Websites -- All DOE Office Websites (Extended Search)

News Field Notes Blog feed Events feed Employment Research Highlights Data Announcements Education News Archive What's this? Social Media Guidance Radar Backgrounder ARM Scanning...

156

Oscillations in the CMB from Axion Monodromy Inflation  

SciTech Connect

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.

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

157

Testing anthropic predictions for Lambda and the CMB temperature  

E-Print Network (OSTI)

It has been claimed that the observed magnitude of the vacuum energy density is consistent with the distribution predicted in anthropic models, in which an ensemble of universes is assumed. This calculation is revisited, without making the assumption that the CMB temperature is known, and considering in detail the possibility of a recollapsing universe. New accurate approximations for the growth of perturbations and the mass function of dark haloes are presented. Structure forms readily in the recollapsing phase of a model with negative Lambda, so collapse fraction alone cannot forbid Lambda from being large and negative. A negative Lambda is disfavoured only if we assume that formation of observers can be neglected once the recollapsing universe has heated to T > 8 K. For the case of positive Lambda, however, the current universe does occupy a extremely typical position compared to the predicted distribution on the Lambda-T plane. Contrasting conclusions can be reached if anthropic arguments are applied to the curvature of the universe, and we discuss the falsifiability of this mode of anthropic reasoning.

J. A. Peacock

2007-05-07T23:59:59.000Z

158

Detecting anomalies in CMB maps: a new method  

E-Print Network (OSTI)

Ever since WMAP announced its first results, different analyses have shown that there is weak evidence for several large-scale anomalies in the CMB data. While the evidence for each anomaly appears to be weak, the fact that there are multiple seemingly unrelated anomalies makes it difficult to account for them via a single statistical fluke. So, one is led to considering a combination of these anomalies. But, if we "hand-pick" the anomalies (test statistics) to consider, we are making an \\textit{a posteriori} choice. In this article, we propose two statistics that do not suffer from this problem. The statistics are linear and quadratic combinations of the $a_{\\ell m}$'s with random co-efficients, and they test the null hypothesis that the $a_{\\ell m}$'s are independent, normally-distributed, zero-mean random variables with an $m$-independent variance. The motivation for such statistics is generality; equivalently, it is a non \\textit{a posteriori} choice. But, a very useful by-product of considering such stat...

Neelakanta, Jayanth T

2015-01-01T23:59:59.000Z

159

Constraining Hybrid Natural Inflation with recent CMB data  

E-Print Network (OSTI)

We study the {\\it Hybrid Natural Inflation} ({\\it HNI}) model and some of its realisations in the light of recent CMB observations, mainly Planck temperature and WMAP-9 polarization, and compare with the recent release of BICEP2 dataset. The inflationary sector of {\\it HNI} is essentially given by the potential $V(\\phi) = V_0(1+a\\cos (\\frac{\\phi}{f} ) )$, where $a$ is a positive constant smaller or equal to one and $f$ is the scale of (pseudo Nambu-Goldstone) symmetry breaking. We show that to describe the {\\it HNI} model realisations we only need two observables; the spectral index $n_s$, the tensor-to-scalar ratio, and a free parameter in the amplitude of the cosine function $a$. We find that in order to make the {\\it HNI} model compatible with the BICEP2 observations, we require a large positive running of the spectra. We find that this could over-produce PBHs in the most theoretically consistent case of the model. This situation could be aleviated if, as recently argued, the BICEP2 data do not correspond ...

Vazquez, J Alberto; German, Gabriel; Herrera-Aguilar, Alfredo; Hidalgo, Juan Carlos

2014-01-01T23:59:59.000Z

160

CMB polarization power spectra contributions from a network of cosmic strings  

E-Print Network (OSTI)

We present the first calculation of the possible (local) cosmic string contribution to the cosmic microwave background polarization spectra from simulations of a string network (rather than a stochastic collection of unconnected string segments). We use field theory simulations of the Abelian Higgs model to represent local U(1) strings, including their radiative decay and microphysics. Relative to previous estimates, our calculations show a shift in power to larger angular scales, making the chance of a future cosmic string detection from the B-mode polarization slightly greater. We explore a future ground-based polarization detector, taking the CLOVER project as our example. In the null hypothesis (that cosmic strings make a zero contribution) we find that CLOVER should limit the string tension \\mu to G\\mu<0.12e-6 (where G is the gravitational constant), above which it is likely that a detection would be possible.

Neil Bevis; Mark Hindmarsh; Martin Kunz; Jon Urrestilla

2007-04-28T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Correlating Fourier phase information with real-space higher order statistics in CMB data  

Science Journals Connector (OSTI)

We present a heuristic study on the correlations between harmonic space phase information and higher-order statistics. Using the spherical full-sky maps of the cosmic microwave background as an example, we demonstrate that known phase correlations at large spatial scales can gradually be diminished when subtracting a suitable best-fit (Bianchi-)template map of a given strength. The weaker phase correlations are attended by a vanishing signature of anisotropy when measuring the Minkowski functionals and scaling indices in real space with the aid of surrogate maps being free of phase correlations. Those investigations can open a new road to a better understanding of signatures of non-Gaussianities in complex spatial structures, especially by elucidating the meaning of Fourier phase correlations and their influence on higher-order statistics.

H.?I. Modest, C. Räth, A.?J. Banday, K.?M. Górski, and G.?E. Morfill

2014-06-05T23:59:59.000Z

162

A microwave impedance meter  

E-Print Network (OSTI)

A MICROWAVE IMPEDANCE METER A Thesis Virgil Layfaette 8oaz Submitted to the Graduate School of the Agricultural and Mechanical College oi' Texas in partial fulfillment of the requirements for the degree of MASTER OF SC I ENCE August 1 g61... and advice of Dr. J. P, German who suggested the research proj ct and rendered assistance when necessary. Further thanks are extended to the Electrical Engineering Faculty and Staff for their patience and suggestions, 1v CONTENTS LIST OF FIGURES...

Boaz, Virgil Layfaette

2012-06-07T23:59:59.000Z

163

Cryogenic Microwave Anisotropic Artificial Frank Trang  

E-Print Network (OSTI)

Cryogenic Microwave Anisotropic Artificial Materials by Frank Trang B.S., University of California entitled: Cryogenic Microwave Anisotropic Artificial Materials written by Frank Trang has been approved.D., Electrical Engineering) Cryogenic Microwave Anisotropic Artificial Materials Thesis directed by Professor

Popovic, Zoya

164

Metamaterial microwave holographic imaging system  

Science Journals Connector (OSTI)

We demonstrate a microwave imaging system that combines advances in metamaterial aperture design with emerging computational imaging techniques. The flexibility inherent to...

Hunt, John; Gollub, Jonah; Driscoll, Tom; Lipworth, Guy; Mrozack, Alex; Reynolds, Matthew S; Brady, David J; Smith, David R

2014-01-01T23:59:59.000Z

165

Microwave and optical saturable absorption in graphene  

Science Journals Connector (OSTI)

We report on the first experiments on saturable absorption in graphene at microwave frequency band. Almost independent of the incident frequency, microwave absorbance of graphene...

Zheng, Zhiwei; Zhao, Chujun; Lu, Shunbin; Chen, Yu; Li, Ying; Zhang, Han; Wen, Shuangchun

2012-01-01T23:59:59.000Z

166

 

NLE Websites -- All DOE Office Websites (Extended Search)

microwave sky beyond CMB using cross correlations microwave sky beyond CMB using cross correlations Amir Hajian (CITA) Abstract: Past decade has been a golden era for precision cosmology. Cosmological surveys combined with Cosmic Microwave Background (CMB) provided us with valuable tools for studying the physics of the universe. Using a series of high-resolution and high-sensitivity CMB experiments, we have learned a great deal about the material content, shape and structure of the universe. These achievements have come about with the help of precise characterization of the statistical properties of the CMB fluctuations. In this talk, I will discuss the new astrophysical playground the current generation of the CMB experiments has opened up for us. I will describe how interesting information, beyond the traditional CMB power spectrum

167

Plume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a,b  

E-Print Network (OSTI)

to follow a power-law size distribution, estimated a plume heat flux as high as 35% of surface heat fluxPlume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a, of the heat conducted across the CMB. Here this assumption is explored using numerical convection models

Tackley, Paul J.

168

Microwave and Pulsed Power  

SciTech Connect

The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

Freytag, E.K.

1993-03-01T23:59:59.000Z

169

EBSD Images Theoretical Background  

E-Print Network (OSTI)

Motivation EBSD Images Theoretical Background Defects in the Weld Grain Growth Low Speed Welding High Speed Welding Conclusion Heat-Affected Zone Observations Welding Experiments The low density in the transportation industries. Reproducibility and the low cost make welding a major large scale assembly process

Candea, George

170

David Smith Academic background  

E-Print Network (OSTI)

David Smith Academic background Ph.D. in Mathematics (Algebra), Université de Sherbrooke, Canada project program (I. Assem, F. Bergeron, C. Reutenauer, D. Smith) $132,000 ($44,000 per year for 3 years. Schiffler and D. Smith, Friezes, strings and cluster variables, to appear in Glasgow Mathematcal Journal. 2

171

New CMB (and other) Tests of Inflation, Dark Energy, and other  

E-Print Network (OSTI)

associated with new ultra-high-energy physics (e.g., grand unification, strings, supersymmetry, extra spacetime acts as lens: "flat" "open" "closed" (MK, Spergel, Sugiyama 1994) #12;Map of CMB (Boomerang 2000 a curl "E modes" "B modes" (MK, Kosowsky, Stebbins 1996; Seljak, Zaldarriaga 1996) #12;#12;And one final

Weaver, Harold A. "Hal"

172

Probing dark energy and neutrino mass from upcoming lensing experiments of CMB and galaxies  

SciTech Connect

We discuss the synergy of the cosmic shear and CMB lensing experiments to simultaneously constrain the neutrino mass and dark energy properties. Taking fully account of the CMB lensing, cosmic shear, CMB anisotropies, and their cross correlation signals, we clarify a role of each signal, and investigate the extent to which the upcoming observations by a high-angular resolution experiment of CMB and deep galaxy imaging survey can tightly constrain the neutrino mass and dark energy equation-of-state parameters. Including the primary CMB information as a prior cosmological information, the Fisher analysis reveals that the time varying equation-of-state parameters, given by w(a) = w{sub 0}+w{sub a}(1?a), can be tightly constrained with the accuracies of 5% for w{sub 0} and 15% for w{sub a}, which are comparable to or even better than those of the stage-III type surveys neglecting the effect of massive neutrinos. In other words, including the neutrino mass in the parameter estimation would not drastically alter the figure-of-Merit estimates of dark energy parameters from the weak lensing measurements. For the neutrino mass, a clear signal for total neutrino mass with ? 0.1 eV can be detected with ? 2-? significance. The robustness and sensitivity of these results are checked in detail by allowing the setup of cosmic shear experiment to vary as a function of observation time or exposure time, showing that the improvement of the constraints very weakly depends on the survey parameters, and the results mentioned above are nearly optimal for the dark energy parameters and the neutrino mass.

Namikawa, Toshiya; Saito, Shun [Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Taruya, Atsushi, E-mail: namikawa@utap.phys.s.u-tokyo.ac.jp, E-mail: ssaito@astro.berkeley.edu, E-mail: ataruya@utap.phys.s.u-tokyo.ac.jp [Research Center for the Early Universe, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2010-12-01T23:59:59.000Z

173

Microwave Regenerated DPF for Auxiliary Power Units and Diesel...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles Microwave regeneration...

174

Gigatron microwave amplifier  

DOE Patents (OSTI)

An electron tube for achieving high power at high frequency with high efficiency is described, including an input coupler, a ribbon-shaped electron beam and a traveling wave output coupler. The input coupler is a lumped constant resonant circuit that modulates a field emitter array cathode at microwave frequency. A bunched ribbon electron beam is emitted from the cathode in periodic bursts at the desired frequency. The beam has a ribbon configuration to eliminate limitations inherent in round beam devices. The traveling wave coupler efficiently extracts energy from the electron beam, and includes a waveguide with a slot there through for receiving the electron beam. The ribbon beam is tilted at an angle with respect to the traveling wave coupler so that the electron beam couples in-phase with the traveling wave in the waveguide. The traveling wave coupler thus extracts energy from the electron beam over the entire width of the beam.

McIntyre, P.M.

1993-07-13T23:59:59.000Z

175

Gigatron microwave amplifier  

DOE Patents (OSTI)

An electron tube for achieving high power at high frequency with high efficiency, including an input coupler, a ribbon-shaped electron beam and a traveling wave output coupler. The input coupler is a lumped constant resonant circuit that modulates a field emitter array cathode at microwave frequency. A bunched ribbon electron beam is emitted from the cathode in periodic bursts at the desired frequency. The beam has a ribbon configuration to eliminate limitations inherent in round beam devices. The traveling wave coupler efficiently extracts energy from the electron beam, and includes a waveguide with a slot therethrough for receiving the electron beam. The ribbon beam is tilted at an angle with respect to the traveling wave coupler so that the electron beam couples in-phase with the traveling wave in the waveguide. The traveling wave coupler thus extracts energy from the electron beam over the entire width of the beam.

McIntyre, Peter M. (611 Montclair, College Station, TX 77840)

1993-01-01T23:59:59.000Z

176

Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations  

SciTech Connect

The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with ?m{sub ?} = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ??} involved in neutrinoless double beta decay (??0?) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ??0? experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ??0? events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.

Gómez-Cadenas, J.J.; Martín-Albo, J.; Vidal, J. Muñoz; Peña-Garay, C., E-mail: gomez@mail.cern.ch, E-mail: jmalbos@ific.uv.es, E-mail: jmunoz@ific.uv.es, E-mail: penya@ific.uv.es [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia Calle Catedrático José Beltrán, 2, 46090 Paterna, Valencia (Spain)

2013-03-01T23:59:59.000Z

177

Archeops: A CMB anisotropy balloon experiment measuring a broad range of angular scales  

E-Print Network (OSTI)

The Cosmic Microwave Background Radiation is the oldest photon radiation that can be observed, having been emitted when the Universe was about 300,000 year old. It is a blackbody at 2.73 K, and is almost perfectly isotropic, the anisotropies being about one part to 100,000. However, these anisotropies, detected by the COBE satellite in 1992, constrain the cosmological parameters such as the curvature of the Universe. Archeops is a balloon-borne experiment designed to map these anisotropies. The instrument is composed of a 1.5 m telescope and bolometers cooled at 85 mK to detect radiation between 150 and 550 GHz. To lower parasitic signals, the instrument is borne by a stratospheric balloon during the arctic night. This instrument is also a preparation for the Planck satellite mission, as its design is similar to HFI. We discuss here the results of the first scientific flight from Esrange (near Kiruna, Sweden) to Russia on January 29th 2001, which led to a 22 % (sub)millimetre sky coverage unprecedented at this resolution. Here, we put some emphasis on interstellar dust foreground emission observations.

F. -Xavier Desert; the Archeops Collaboration

2001-12-01T23:59:59.000Z

178

Archeops: A balloon experiment to measure CMB anisotropies with a broad range of angular sizes  

E-Print Network (OSTI)

The Cosmic Microwave Background Radiation is the oldest photon radiation that can be observed, having been emitted when the Universe was about 300,000 year old. It is a blackbody at 2.73 K, and is almost perfectly isotropic, the anisotropies being about one part to 100,000. However, these anisotropies, detected by the COBE satellite in 1992, constrain the cosmological parameters such as the curvature of the Universe. Archeops is a balloon-borne experiment designed to map these anisotropies. The instrument is composed of a 1.5 m telescope and bolometers cooled at 85 mK to detect radiation between 150 and 550 GHz. To lower atmosphere parasitic signal, the instrument is lifted at 32 km altitude with a stratospheric balloon during the arctic night. This instrument is also a preparation for the Planck satellite mission, as its design is similar. We discuss here the results of the first scientific flight from Esrange (near Kiruna, Sweden) to Russia on January 29th 2001, which led to a 22 % (sub)millimetre sky coverage unprecedented at this resolution.

A. Benoit; the Archeops Collaboration

2001-12-01T23:59:59.000Z

179

Paducah Background Factsheet | Department of Energy  

Office of Environmental Management (EM)

Background Factsheet Paducah Background Factsheet Background Fact Sheet Transfer of Depleted Uranium and Subsequent Transactions, May 15, 2012 Paducah Background...

180

Thermodynamics of water superheated in the microwave oven  

Science Journals Connector (OSTI)

Water is conveniently heated above its normal boiling point in a microwave oven in a glass microwave oven teapot. ...

B. H. Erné; Penny Snetsinger

2000-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Current Dark Matter Annihilation Constraints from CMB and Low-Redshift Data  

E-Print Network (OSTI)

Updated constraints on dark matter cross section and mass are presented combining CMB power spectrum measurements from Planck, WMAP9, ACT, and SPT as well as several low-redshift datasets (BAO, HST, supernovae). For the CMB datasets, we combine WMAP9 temperature and polarization data for l 2500, and Planck CMB four-point lensing measurements. We allow for redshift-dependent energy deposition from dark matter annihilation by using a `universal' energy absorption curve. We also include an updated treatment of the excitation, heating, and ionization energy fractions, and provide updated deposition efficiency factors (f_eff) for 41 different dark matter models. Assuming perfect energy deposition (f_eff = 1) and a thermal cross section, dark matter masses below 26 GeV are excluded at the 2-sigma level. Assuming a more generic efficiency of f_eff = 0.2, thermal dark matter masses below 5 GeV are disfavored at the 2-sigma level. These limits are a factor of ~2 improvement over those from WMAP9 data alone. These current constraints probe, but do not exclude, dark matter as an explanation for reported anomalous indirect detection observations from AMS-02/PAMELA and the Fermi Gamma-ray Inner Galaxy data. They also probe relevant models that would explain anomalous direct detection events from CDMS, CRESST, CoGeNT, and DAMA, as originating from a generic thermal WIMP. Projected constraints from the full Planck release should improve the current limits by another factor of ~2, but will not definitely probe these signals. The proposed CMB Stage IV experiment will more decisively explore the relevant regions and improve upon the Planck constraints by another factor of ~2.

Mathew S. Madhavacheril; Neelima Sehgal; Tracy R. Slatyer

2014-11-28T23:59:59.000Z

182

Microwavable thermal energy storage material  

DOE Patents (OSTI)

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

Salyer, Ival O. (Dayton, OH)

1998-09-08T23:59:59.000Z

183

Microwavable thermal energy storage material  

DOE Patents (OSTI)

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

Salyer, I.O.

1998-09-08T23:59:59.000Z

184

Microwave assisted centrifuge and related methods  

DOE Patents (OSTI)

Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

Meikrantz, David H. (Idaho Falls, ID) [Idaho Falls, ID

2010-08-17T23:59:59.000Z

185

Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources  

E-Print Network (OSTI)

Almost the totality of the bright foreground sources in the WMAP CMB maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope $\\alpha_{mu x}$ of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Sychrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies a...

Giommi, P; Cavazzuti, E; Colafrancesco, S; Cucchiara, A; Falcone, A; Kennea, J; Nesci, R; Perri, M; Tagliaferri, G; Tramacere, A; Tosti, G; Blustin, A J; Branduardi-Raymont, G; Burrows, D N; Chincarini, G; Dean, A J; Gehrels, N; Krimm, H; Marshall, F; Parsons, A M; Zhang, B

2007-01-01T23:59:59.000Z

186

Microwave scattering from laser spark in air  

SciTech Connect

In this paper, microwave Mie scattering from a laser-induced plasma in atmospheric air is computed. It shows that the scattered microwave transitions from coherent Rayleigh scattering to Mie scattering based on the relative transparency of the laser-induced plasma at the microwave frequency. The microwave penetration in the plasma alters from total transparency to partial shielding due to the sharp increase of the electron number density within the avalanche ionization phase. The transition from Rayleigh scattering to Mie scattering is verified by both the temporal evolution of the scattered microwave and the homogeneity of polar scattering plots.

Sawyer, Jordan; Zhang Zhili [Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Shneider, Mikhail N. [Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2012-09-15T23:59:59.000Z

187

Adhesive bonding using variable frequency microwave energy  

DOE Patents (OSTI)

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Paulauskas, Felix L. (Oak Ridge, TN); Fathi, Zakaryae (Cary, NC); Wei, Jianghua (Raleigh, NC)

1998-01-01T23:59:59.000Z

188

Adhesive bonding using variable frequency microwave energy  

DOE Patents (OSTI)

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-09-08T23:59:59.000Z

189

Adhesive bonding using variable frequency microwave energy  

DOE Patents (OSTI)

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-08-25T23:59:59.000Z

190

Scanning tip microwave near field microscope  

DOE Patents (OSTI)

A microwave near field microscope has a novel microwave probe structure wherein the probing field of evanescent radiation is emitted from a sharpened metal tip instead of an aperture or gap. This sharpened tip, which is electrically and mechanically connected to a central electrode, extends through and beyond an aperture in an endwall of a microwave resonating device such as a microwave cavity resonator or a microwave stripline resonator. Since the field intensity at the tip increases as the tip sharpens, the total energy which is radiated from the tip and absorbed by the sample increases as the tip sharpens. The result is improved spatial resolution without sacrificing sensitivity.

Xiang, Xiao-Dong (Alameda, CA); Schultz, Peter G. (Oakland, CA); Wei, Tao (Albany, CA)

1998-01-01T23:59:59.000Z

191

Microwave sintering of boron carbide  

DOE Patents (OSTI)

A method for forming boron carbide into a particular shape and densifying the green boron carbide shape. Boron carbide in powder form is pressed into a green shape and then sintered, using a microwave oven, to obtain a dense boron carbide body. Densities of greater than 95% of theoretical density have been obtained. 1 tab.

Blake, R.D.; Katz, J.D.; Petrovic, J.J.; Sheinberg, H.

1988-06-10T23:59:59.000Z

192

SKA - EoR correlations and cross-correlations: kSZ, radio galaxies, and NIR background  

E-Print Network (OSTI)

The Universe's Cosmic Dawn (CD) and Epoch of Reionization (EoR) can be studied using a number of observational probes that provide complementary or corroborating information. Each of these probes suffers from its own systematic and statistical uncertainties. It is therefore useful to consider the mutual information that these data sets contain. In this paper, we discuss a potential of cross-correlations between the SKA cosmological 21 cm data with: (i) the kinetic Sunyaev- Zel'dovich (kSZ) effect in the CMB data; (ii) the galaxy surveys; and (iii) near infrared (NIR) backgrounds.

Jelic, Vibor; Fernandez, Elizabeth; Tashiro, Hiroyuki; Vrbanec, Dijana

2015-01-01T23:59:59.000Z

193

MAR Background Report MAR Background Report: Indigenous Protest in Brazil  

E-Print Network (OSTI)

MAR Background Report MAR Background Report: Indigenous Protest in Brazil Hundreds of indigenous people demonstrated at the National Congress in Brasilia, capital of Brazil, following the announcement in the 1990s in the midst of extensive protests in Brazil and around the world. On February 8, an indigenous

Milchberg, Howard

194

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Solar panels are designed as a photovoltaic module. The energy producing aspect of the photovoltaic module has two primary steps. The first is a semiconducting material such as...

195

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

and the Bureau of Reclamation signed 10-year agreements - known as the Columbia Basin Fish Accords - with four Northwest tribes and two states on May 2, 2008. These historic...

196

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

maintenance personnel, and film crews use small, portable lighting systems known as "mobile lighting." Traditionally, mobile lighting units are powered by diesel fuel generators...

197

Background  

Science Journals Connector (OSTI)

Onondaga Lake is located (lat. 43°06?54?; long. 76°14?34?) immediately north of the City of Syracuse, in Onondaga County, in the middle of the most urbanized ... River. The Seneca River combines with the Oneida R...

Steven W. Effler; Gena Harnett

1996-01-01T23:59:59.000Z

198

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Bonneville Power Administration is considering building a new office building on its Ross Complex in Vancouver, Wash., to meet long-standing work space needs. BPA is inviting...

199

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Administration, January 14, 2011 Figure 2 - Natural Gas Rig Count U.S. Natural Gas Rotary Rigs in Operation (Count) 0 400 800 1200 1600 2000 J a n - 0 7 M a r - 0 7 M a y -...

200

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Renewable energy sources are critical to the nation's future, and hydrogen-powered fuel cells offer an attractive alternative to current technologies. However, fuel cell...

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Background  

Office of Scientific and Technical Information (OSTI)

Energy Star Lighting Verification Program (Program for the Evaluation and Analysis of Residential Lighting) Semi-annual report For the period of October 2003 to April 2004 Authored...

202

Background  

NLE Websites -- All DOE Office Websites (Extended Search)

build a facility in the Sandia Science & Technology Park (SS&TP) in 1998 for their Photovoltaics Division, which builds solar cells for the space industry. This division is built...

203

Note: Cryogenic coaxial microwave filters  

SciTech Connect

The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

Tancredi, G.; Meeson, P. J. [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom)] [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Schmidlin, S. [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom) [Department of Physics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom)

2014-02-15T23:59:59.000Z

204

Microwave assisted hard rock cutting  

DOE Patents (OSTI)

An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

Lindroth, David P. (Apple Valley, MN); Morrell, Roger J. (Bloomington, MN); Blair, James R. (Inver Grove Heights, MN)

1991-01-01T23:59:59.000Z

205

Microwave solidification development for Rocky Flats waste  

SciTech Connect

The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology.

Dixon, D.; Erle, R.; Eschen, V. [and others

1994-04-01T23:59:59.000Z

206

Constraining a bulk viscous matter-dominated cosmological model using SNe Ia, CMB and LSS  

E-Print Network (OSTI)

We present and constrain a cosmological model which component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a constant bulk viscosity coefficient \\zeta_m. The possible values of \\zeta_m are constrained using the cosmological tests of SNe Ia Gold 2006 sample, the CMB shift parameter R from the three-year WMAP observations, the Baryon Acoustic Oscillation (BAO) peak A from the Sloan Digital Sky Survey (SDSS) and the Second Law of Thermodynamics (SLT). It was found that this model is in agreement with the SLT using only the SNe Ia test. However when the model is submitted to the three cosmological tests together (SNe+CMB+BAO) the results are: 1.- the model violates the SLT, 2.- predicts a value of H_0 \\approx 53 km sec^{-1} Mpc^{-1} for the Hubble constant, and 3.- we obtain a bad fit to data with a \\chi^2_{min} \\approx 400 (\\chi^2_{d.o.f.} \\approx 2.2). These results indicate that this model is ruled out by the observations.

Arturo Avelino; U. Nucamendi; F. S. Guzmán

2008-01-10T23:59:59.000Z

207

Planck CMB Anomalies: Astrophysical and Cosmological Foregrounds and the Curse of Masking  

E-Print Network (OSTI)

Understanding the origin of reported anomalies in the CMB is fundamental to either validate the standard model of cosmology or to explore new physics. Their confirmation with Planck data suggests they are not due to a problem in WMAP or Planck data. We investigate three other possible issues: 1) the trade-off between minimising systematics due to foreground contamination (with a conservative mask) and minimising systematics due to masking, 2) astrophysical foregrounds (the kinetic Doppler quadrupole and kinetic Sunyaev-Zel'dovich effect), and 3) secondary cosmological signals (the integrated Sachs-Wolfe effect). We address the masking issue by considering new procedures that use both WMAP and Planck to produce higher quality full-sky maps using the sparsity methodology (LGMCA maps). We show the impact of masking is dominant over that of residual foregrounds, and the LGMCA full-sky maps can be used without further processing to study anomalies. We consider four official Planck PR1 and two LGMCA CMB maps. Analy...

Rassat, A; Paykari, P; Sureau, F; Bobin, J

2014-01-01T23:59:59.000Z

208

Constraints on early dark energy from CMB lensing and weak lensing tomography  

SciTech Connect

Dark energy can be studied by its influence on the expansion of the Universe as well as on the growth history of the large-scale structure. In this paper, we follow the growth of the cosmic density field in early dark energy cosmologies by combining observations of the primary CMB temperature and polarisation power spectra at high redshift, of the CMB lensing deflection field at intermediate redshift and of weak cosmic shear at low redshifts for constraining the allowed amount of early dark energy. We present these forecasts using the Fisher matrix formalism and consider the combination of Planck data with the weak lensing survey of Euclid. We find that combining these data sets gives powerful constraints on early dark energy and is able to break degeneracies in the parameter set inherent to the various observational channels. The derived statistical 1{sigma}-bound on the early dark energy density parameter is {sigma}({Omega}{sup e}{sub d}) = 0.0022 which suggests that early dark energy models can be well examined in our approach. In addition, we derive the dark energy figure of merit for the considered dark energy parameterisation and comment on the applicability of the growth index to early dark energy cosmologies.

Hollenstein, Lukas; Crittenden, Robert [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom)] [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Sapone, Domenico [Departement de Physique Theorique, Universite de Geneve, 24 Quai Ernest-Ansermet, CH-1211 Geneve 4 (Switzerland)] [Departement de Physique Theorique, Universite de Geneve, 24 Quai Ernest-Ansermet, CH-1211 Geneve 4 (Switzerland); Schaefer, Bjoern Malte, E-mail: lukas.hollenstein@port.ac.uk, E-mail: domenico.sapone@unige.ch, E-mail: robert.crittenden@port.ac.uk, E-mail: spirou@ita.uni-heidelberg.de [Astronomisches Recheninstitut, Zentrum fuer Astronomie, Universitaet Heidelberg, Moenchhofstrasse 12, 69120 Heidelberg (Germany)

2009-04-15T23:59:59.000Z

209

Aluminum as a source of background in low background experiments  

E-Print Network (OSTI)

Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10^-5 counts/(kg y keV) in the region of interest around the Q value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of 22Na, 26Al, 226Ra and 228Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

B. Majorovits; I. Abt; M. Laubenstein; O. Volynets

2011-05-18T23:59:59.000Z

210

Process for microwave sintering boron carbide  

DOE Patents (OSTI)

A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

Holcombe, C.E.; Morrow, M.S.

1993-10-12T23:59:59.000Z

211

Process for microwave sintering boron carbide  

DOE Patents (OSTI)

A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

Holcombe, Cressie E. (440 Sugarwood Dr., Knoxville, TN 37922); Morrow, Marvin S. (Rte. #3, Box 113, Kingston, TN 37763)

1993-01-01T23:59:59.000Z

212

Expanded Capacity Microwave-Cleaned Diesel Particulate Filter...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Expanded Capacity Microwave-Cleaned Diesel Particulate Filter Expanded Capacity Microwave-Cleaned Diesel Particulate Filter 2002 DEER Conference Presentation: Industrial Ceramic...

213

New Energy Efficiency Standards for Microwave Ovens to Save Consumers...  

Energy Savers (EERE)

New Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills New Energy Efficiency Standards for Microwave Ovens to Save Consumers on Energy Bills May 31,...

214

Energy Efficiency Standards for Microwave Ovens Saves Consumers...  

Energy Savers (EERE)

Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy and Updates the Social Cost of Carbon Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy...

215

Low background techniques in XMASS  

SciTech Connect

The XMASS project aims to detect pp and {sup 7}Be solar neutrinos, neutrino-less double beta decay, and dark matter searches using ultra-pure liquid xenon. The first stage of XMASS project is concentrated on dark matter searches using 800 kg liquid xenon detector which requires low background and low threshold. Several techniques applied to XMASS detector for low background will be presented.

Takeda, Atsushi [Kamioka Observatory, ICRR, University of Tokyo, 456 Higashi-Mozumi, Kamioka-cho, Hida, Gifu, 506-1205 (Japan)

2011-04-27T23:59:59.000Z

216

Measurements of Secodary Cosmic Microwave Background Anisotropies with the South Pole Telescope  

E-Print Network (OSTI)

dark lines indicate regions where the underlying silicon has been etched away leaving the spiderweb membrane suspended, although the web

Lueker, Martin Van

2010-01-01T23:59:59.000Z

217

Antenna-coupled Superconducting Bolometers for Observations of the Cosmic Microwave Background Polarization  

E-Print Network (OSTI)

ment with Newton’s law of gravitation. Only in cases ofpublished his Law of Universal Gravitation. This theory

Myers, Michael James

2010-01-01T23:59:59.000Z

218

Implications about the large scale properties of the universe from the cosmic microwave background  

E-Print Network (OSTI)

power spectrum, the correlation between ? lm ’s takesthe form ? lm ? ? l ? m ? = ? ll ? ? mm ? C l ? C l ? = 4?spherical harmonics n , x) = a lm (x)Y lm (ˆ n ) , lm where

Aslanyan, Grigor; Aslanyan, Grigor

2012-01-01T23:59:59.000Z

219

Measurement of the Cosmic Microwave Background Polarization with the BICEP Telescope at the South Pole  

E-Print Network (OSTI)

temperatures of the adsorption pumps, gas-gap heat switches,operating the adsorption pumps and the heat switches, for

Takahashi, Yuki David

2010-01-01T23:59:59.000Z

220

A Log-Periodic Focal-Plane Architecture for Cosmic Microwave Background Polarimetry  

E-Print Network (OSTI)

and etched the ?lms with a CF4 plasma ( Hamilton [2010]).We mixed the CF4 with trace amounts of O2 to wear away the

OBrient, Roger

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Scientific results from the Cosmic Background Explorer (COBE): (microwave/infrared)  

Science Journals Connector (OSTI)

...Laboratory for Astronomy and Solar Physics, Greenbelt...Physics, Room 20F-001, Massachusetts Institute of Technology...Extensive modeling of solar system and galactic...Laboratory for Astronomy and Solar Physics, Greenbelt...Physics, Room 20F-001, Massachusetts Institute of Technology...

C. L. Bennett; N. W. Boggess; E. S. Cheng; M. G. Hauser; T. Kelsall; J. C. Mather; S. H. Moseley; Jr.; T. L. Murdock; R. A. Shafer; R. F. Silverberg; G. F. Smoot; R. Weiss; E. L. Wright

1993-01-01T23:59:59.000Z

222

Measurements of Secodary Cosmic Microwave Background Anisotropies with the South Pole Telescope  

E-Print Network (OSTI)

the physics of Josephson junctions, SQUID noise performance,insulating barriers, or Josephson junctions(Josephson, 1962;current, I c , of a Josephson junction determine how much

Lueker, Martin Van

2010-01-01T23:59:59.000Z

223

Neutrino Degeneracy and Decoupling: New Limits from Primordial Nucleosynthesis and the Cosmic Microwave Background  

E-Print Network (OSTI)

We reanalyze the cosmological constraints on the existence of a net universal lepton asymmetry and neutrino degeneracy. We show that neutrinos can begin to decouple at higher temperatures than previous estimates due to several corrections which diminish the neutrino reaction rate. These decoupled neutrinos are therefore not heated as the particle degrees of freedom change. The resultant ratio of the relic neutrino-to-photon temperatures after $e^\\pm$ annihilation can then be significantly reduced by more than a factor of two from that of the standard nondegenerate ratio. This changes the expansion rate and subsequent primordial nucleosynthesis, photon decoupling, and structure formation. In particular we analyze physically plausible lepton-asymmetric models with large $\

M. Orito; T. Kajino; G. J. Mathews; R. N. Boyd

2000-05-23T23:59:59.000Z

224

Universal Lepton Asymmetry: New Constraints from the Cosmic Microwave Background and Primordial Nucleosynthesis  

E-Print Network (OSTI)

We study the primordial nucleosynthesis and cosmic age in the presence of a net lepton asymmetry as well as baryon asymmetry. We explore a previously unnoted region of the parameter space in which very large baryon densities $0.1 \\le \\Omega_b \\le 1$ can be accommodated within the light-element constraints from primordial nucleosynthesis. This parameter space consists of $\

T. Kajino; M. Orito; G. J. Mathews; R. N. Boyd

2002-02-06T23:59:59.000Z

225

Observing dark energy dynamics with supernova, microwave background, and galaxy clustering  

Science Journals Connector (OSTI)

Observing dark energy dynamics is the most important aspect of the current dark energy research. In this paper we perform a global analysis of the constraints on the property of dark energy from the current observations. We pay particular attention to the effects of dark energy perturbations. Using the data from SNIa (157 gold sample), WMAP, and SDSS we find that the best fitting dark energy model is given by the dynamical model with the equation of state crossing -1. Nevertheless the standard ?CDM model is still a good fit to the current data and evidence for dynamics is currently not very strong. We also consider the constraints with the recent released SNIa data from Supernova Legacy Survey.

Jun-Qing Xia; Gong-Bo Zhao; Bo Feng; Hong Li; Xinmin Zhang

2006-03-20T23:59:59.000Z

226

Solar Background Document 3 | Department of Energy  

Energy Savers (EERE)

3 Solar Background Document 3 A list of private sector investment in Solyndra. Solar Background Document 3.pdf More Documents & Publications Solar Background Document 2 GridWise...

227

Tandem microwave waste remediation and decontamination system  

DOE Patents (OSTI)

The invention discloses a tandem microwave system consisting of a primary chamber in which microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

Wicks, George G. (North Aiken, SC); Clark, David E. (Gainesville, FL); Schulz, Rebecca L. (Gainesville, FL)

1999-01-01T23:59:59.000Z

228

Relating gravitational wave constraints from primordial nucleosynthesis, pulsar timing, laser interferometers, and the CMB: Implications for the early universe  

Science Journals Connector (OSTI)

We derive a general equation relating the gravitational-wave observables r and ?0gw(f); or the observables ?0gw(f1) and ?0gw(f2). Here, r is the so-called “tensor-to-scalar ratio,” which is constrained by cosmic-microwave-background experiments; and ?0gw(f) is the energy spectrum of primordial gravitational waves, which is constrained, e.g., by pulsar-timing measurements, laser-interferometer experiments, and the standard big bang nucleosynthesis bound. Differentiating this equation yields a new expression for the tilt dln??0gw(f)/dln?f of the present-day gravitational-wave spectrum. The relationship between r and ?0gw(f) depends sensitively on the uncertain physics of the early universe, and we show that this uncertainty may be encapsulated (in a model-independent way) by two quantities: w^(f) and n^t(f), where n^t(f) is a certain logarithmic average over nt(k) (the primordial tensor spectral index); and w^(f) is a certain logarithmic average over w˜(a) (the effective equation-of-state parameter in the early universe, after horizon re-entry). Here, the effective equation-of-state parameter w˜(a) is a combination of the ordinary equation-of-state parameter w(a) and the bulk viscosity ?(a). Thus, by comparing observational constraints on r and ?0gw(f), one obtains (remarkably tight) constraints in the {w^(f),n^t(f)} plane. In particular, this is the best way to constrain (or detect) the presence of a stiff energy component (with w>1/3) in the early universe, prior to big bang nucleosynthesis. (The discovery of such a component would be no more surprising than the discovery of a tiny cosmological constant at late times!) Finally, although most of our analysis does not assume inflation, we point out that if cosmic-microwave-background experiments detect a nonzero value for r, then we will immediately obtain (as a free by-product) a new upper bound w^?0.55 on the logarithmically averaged effective equation-of-state parameter during the “primordial dark age” between the end of inflation and the start of big bang nucleosynthesis.

Latham A. Boyle and Alessandra Buonanno

2008-08-18T23:59:59.000Z

229

Integrated global background monitoring network  

SciTech Connect

This paper describes the background and elucidates the need for an integrated global background monitoring network. This network should: establish reference levels for pollutants that have potential for global contaminatin, serve as an early warning site for detecting global spread of pollutants, and establish baseline levels for selected ecosystem parameters against which data from more impacted areas can be compared. This paper proposes the following: (1) establish an integrated global background monitoring network for pollutants and ecosystem parameters; (2) pollutant measurements be multi-media; (3) carry out ecosystem parameter studies in conjunction with pollutant measurements; (4) the network be maintained for an indefinite period of time; (5) the network be established using the international biosphere reserve system as the universe from which a subset of monitoring sites are drawn; and (6) that the project be under the overall direction of the Global Environmental Monitoring System. 43 references, 1 figure, 1 table.

Wiersma, G.B.

1984-08-01T23:59:59.000Z

230

Microwave processing for carbide ceramics  

SciTech Connect

The US Bureau of Mines (USBM) has developed a process for synthesizing carbide ceramics in a microwave-induced plasma (MIP). For example, the process forms tungsten carbide with only 0.04% free carbon impurity at an average particle size of 0.05 {mu}m. Starting materials are tungsten oxide, carbon, and carbon monoxide. Commercial methods to produce tungsten carbide require heating to 1,500 C for up to 7 hours. Using the USBM method, tungsten carbide can be produced in approximately 10 minutes using a 30 kW, 915 mHz microwave unit. The reaction is carried out in a short-circuited waveguide to create a standing wave. Reactants rest on a carbon pedestal inside a closed zirconia crucible filled with carbon monoxide. The crucible is place at a field maximum within the waveguide. The waveguide was filled with helium to protect the waveguide. A procedure for producing carbide on a larger scale is described. Other ceramic compounds have been produced using this method, including silicon carbide and titanium carbide.

Tolley, W.K.; Church, R.H. [Bureau of Mines, Salt Lake City, UT (United States). Salt Lake City Research Center

1995-08-01T23:59:59.000Z

231

Microwave sintering of nanocrystalline ceramics  

SciTech Connect

A single-mode cavity microwave furnace, operating in the TE{sub 103} mode at 2.45 GHz, has been set up at the Naval Research Laboratory (NRL) and is currently being used to investigate sintering of nanocrystalline ceramics. This presentation will discuss the apparatus used and the results obtained to date. The high purity Al{sub 2}O{sub 3} and TiO{sub 2} nanocrystalline powders were prepared by the sol-gel method. These powders were first uniaxially pressed to 14 MPa, CIP`ed to various pressures > 420 MPa and finally sectioned into wafers. The density of the green wafers was 30 to 38% TD. The wafers were heated in the microwave furnace for up to three hours at temperatures {<=} 1720{degrees}C. The temperature of the workpiece was monitored using an optical pyrometer. Final densities up to 80% TD have been obtained to date for Al{sub 2}O{sub 3} and up to 52% TD for TiO{sub 2}. Work is ongoing to characterize the sintered compacts, optimize the casketing for this furnace, and lay the groundwork for new studies using a 35 GHz gyrotron and quasioptical gyrotron tunable from 85 to 120 GHz.

Bruce, R.W. [United States Naval Academy, Annapolis, MD (United States); Rayne, R.; Chow, G.M. [Naval Research Lab., Washington, DC (United States)] [and others

1995-12-31T23:59:59.000Z

232

REFERENCE AND BACKGROUND CHECK PROCESS  

E-Print Network (OSTI)

REFERENCE AND BACKGROUND CHECK PROCESS Workforce Planning | 408-924-2250 classcomp process. Workforce Planning will arrange this directly with the finalist(s) once the hiring manager has provided the finalist(s) name(s) to Workforce Planning. An exception to this process is for any candidates

Su, Xiao

233

Integrated Global Background Monitoring Network  

SciTech Connect

One of the more significant problems when trying to determine what impact is having on global cycles is not knowing what ''natural'' levels should be for both abiotic (gases, trace elements) and biotic (ecosystem functions) processes. The authors believe that a well designed, coordinated network of baseline stations in remote areas around the world can provide a data base will allow best current estimates to be made of biotic and abiotic baseline conditions. These baseline conditions will then help us make better comparisons with more impacted areas, and thus help us more fully understand the impact man is having on his world. This paper examines the history of background pollution monitoring at the international level, describes current activities in the field of ''integrated'' background monitoring, and proposes criteria for the development of a global network of baseline stations to coordinate background monitoring for the presence, accumulation and behavior of pollutants in remote ecosystems. In this paper, this network is called the Integrated Global Background Monitoring Network.

Wiersma, G.B.; Franklin, J.F.; Kohler, A.; Croze, H.; Boelcke, C.

1986-12-01T23:59:59.000Z

234

Experiment Design and First Season Observations with the Degree Angular Scale Interferometer  

E-Print Network (OSTI)

We describe the instrumentation, experiment design and data reduction for the first season of observations with the Degree Angular Scale Interferometer (DASI), a compact microwave interferometer designed to measure anisotropy in the Cosmic Microwave Background (CMB) on degree and sub-degree scales (l=100--900). The telescope was deployed at the Amundsen-Scott South Pole research station during the 1999--2000 austral summer and conducted observations of the CMB throughout the following austral winter. In its first season of observations, DASI has mapped CMB fluctuations in 32 fields, each 3.4 deg across, with high sensitivity.

E. M. Leitch; C. Pryke; N. W. Halverson; J. Kovac; G. Davidson; S. LaRoque; E. Schartman; J. Yamasaki; J. E. Carlstrom; W. L. Holzapfel; M. Dragovan; J. K. Cartwright; B. S. Mason; S. Padin; T. J. Pearson; M. C. Shepherd; A. C. S. Readhead

2001-04-30T23:59:59.000Z

235

microwaverpp.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

microwave microwave background 1 26. COSMIC MICROWAVE BACKGROUND Revised September 2013 by D. Scott (University of British Columbia) and G.F. Smoot (UCB/LBNL). 26.1. Introduction The energy content in radiation from beyond our Galaxy is dominated by the cosmic microwave background (CMB), discovered in 1965 [1]. The spectrum of the CMB is well described by a blackbody function with T = 2.7255 K, this spectral form being one of the main pillars of the hot Big Bang model for the early Universe. The lack of any observed deviations from a blackbody spectrum constrains physical processes over cosmic history at redshifts z ∼ < 10 7 (see earlier versions of this review). All viable cosmological models predict a very nearly Planckian spectrum inside the current observational limits (although that could change with more sensitive spectral experiments in the future [2]). Currently the key CMB observable

236

Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager  

NLE Websites -- All DOE Office Websites (Extended Search)

Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) Global Gridded Products Agriculture Community Menu DATA APPS EVENTS DEVELOPER STATISTICS COLLABORATE ABOUT Agriculture You are here Data.gov » Communities » Agriculture » Data Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) Global Gridded Products Dataset Summary Description The SSM/I products are useful for evaluating the mean climate state, it's interannual and seasonal variations, and the detection of anomalies associated with ENSO and regional climatic variations. The Hydrology Team has assembled a time series of the entire SSM/I archive, now entering it's 16th year, which includes data from July 1987 to the present. Monthly average products are produced for precipitation, cloud liquid water, total precipitable water, snow cover, sea-ice cover, and oceanic surface wind speed.

237

Microwave concrete decontamination - Phase II results  

SciTech Connect

This report documents the results of the second phase of a four-phase development program to develop a system to decontaminate concrete using microwave energy. In the first phase of the program the feasibility of using microwaves to remove concrete surfaces was demonstrated. In the first phase experiments, concrete slabs were placed on a translator and moved beneath a stationery microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from concrete floors. Phases III and IV will further develop the technology to be remotely operated and capable of removing concrete from floors as well as from vertical surfaces.

White, T.L.; Foster, D. Jr.

1994-06-01T23:59:59.000Z

238

Chiral-field microwave antennas (Chiral microwave near fields for far-field radiation)  

E-Print Network (OSTI)

In a single-element structure we obtain a radiation pattern with a squint due to chiral microwave near fields originated from a magnetostatic-mode ferrite disk. At the magnetostatic resonances, one has strong subwavelength localization of energy of microwave radiation. Magnetostatic oscillations in a thin ferrite disk are characterized by unique topological properties: the Poynting-vector vortices and the field helicity. The chiral-topology near fields allow obtaining unique phase structure distribution for far-field microwave radiation.

Kamenetskii, E O; Shavit, R

2015-01-01T23:59:59.000Z

239

E-Print Network 3.0 - assessment south microwave Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Process Christopher Marion Supervisor: Prof Kristian Waters Summary: microwaves) Optimization of the microwave pre-treatment process Assess the effect of the microwave pre......

240

Emergent Supersymmetry in Warped Backgrounds  

E-Print Network (OSTI)

We show that quantum mechanical supersymmetries are emerged in Kaluza-Klein spectrum of linearized gravity in several warped backgrounds as a consequence of higher-dimensional general coordinate invariance. These emergent supersymmetries play an essential role for the spectral structure of braneworld gravity. We show that for the case of braneworld models with two codimension-1 branes the spectral pattern is completely determined only through the supersymmetries.

Nagasawa, Tomoaki; Sakamoto, Kazuki; Sakamoto, Makoto

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Emergent Supersymmetry in Warped Backgrounds  

E-Print Network (OSTI)

We show that quantum mechanical supersymmetries are emerged in Kaluza-Klein spectrum of linearized gravity in several warped backgrounds as a consequence of higher-dimensional general coordinate invariance. These emergent supersymmetries play an essential role for the spectral structure of braneworld gravity. We show that for the case of braneworld models with two codimension-1 branes the spectral pattern is completely determined only through the supersymmetries.

Tomoaki Nagasawa; Satoshi Ohya; Kazuki Sakamoto; Makoto Sakamoto

2011-05-24T23:59:59.000Z

242

Planar slot coupled microwave hybrid  

DOE Patents (OSTI)

A symmetrical 180.degree. microwave hybrid is constructed by opening a slot line in a ground plane below a conducting strip disposed on a dielectric substrate, creating a slot coupled conductor. Difference signals propagating on the slot coupled conductor are isolated on the slot line leaving sum signals to propagate on the microstrip. The difference signal is coupled from the slot line onto a second microstrip line for transmission to a desired location. The microstrip branches in a symmetrical fashion to provide the input/output ports of the 180.degree. hybrid. The symmetry of the device provides for balance and isolation between sum and difference signals, and provides an advantageous balance between the power handling capabilities and the bandwidth of the device.

Petter, Jeffrey K. (Williston, VT)

1991-01-01T23:59:59.000Z

243

Modulated microwave microscopy and probes used therewith  

DOE Patents (OSTI)

A microwave microscope including a probe tip electrode vertically positionable over a sample and projecting downwardly from the end of a cantilever. A transmission line connecting the tip electrode to the electronic control system extends along the cantilever and is separated from a ground plane at the bottom of the cantilever by a dielectric layer. The probe tip may be vertically tapped near or at the sample surface at a low frequency and the microwave signal reflected from the tip/sample interaction is demodulated at the low frequency. Alternatively, a low-frequency electrical signal is also a non-linear electrical element associated with the probe tip to non-linearly interact with the applied microwave signal and the reflected non-linear microwave signal is detected at the low frequency. The non-linear element may be semiconductor junction formed near the apex of the probe tip or be an FET formed at the base of a semiconducting tip.

Lai, Keji; Kelly, Michael; Shen, Zhi-Xun

2012-09-11T23:59:59.000Z

244

Container evaluation for microwave solidification project  

SciTech Connect

This document discusses the development and testing of a suitable waste container and packaging arrangement to be used with the Microwave Solidification System (MSS) and Bagless Posting System (BPS). The project involves the Rocky Flats Plant.

Smith, J.A.

1994-08-01T23:59:59.000Z

245

Solar Background Document 6 | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Background Document 6 Graph illustrating solar cell production in the United States and China from 2002 to 2010. Solar Background Document 6.pdf More Documents & Publications Solar...

246

Solar Background Document 1 | Department of Energy  

Energy Savers (EERE)

Solar Background Document 1 Solar Background Document 1 A timeline outlining the Energy Department's extensive review of the Solyndra Solar loan guarantee application from 2006 to...

247

Solar Background Document 5 | Department of Energy  

Energy Savers (EERE)

5 Solar Background Document 5 Graph illustrating Chinese Development Bank financing to Chinese solar companies. Solar Background Document 5.pdf More Documents & Publications Solar...

248

Solar Background Document 6 | Department of Energy  

Energy Savers (EERE)

6 Solar Background Document 6 Graph illustrating solar cell production in the United States and China from 2002 to 2010. Solar Background Document 6.pdf More Documents &...

249

Solar Background Document 2 | Department of Energy  

Energy Savers (EERE)

2 Solar Background Document 2 Media reports and other independent analysts which pointed to Solyndra as a very promising, innovative company. Solar Background Document 2.pdf More...

250

Solar Background Document 4 | Department of Energy  

Energy Savers (EERE)

4 Solar Background Document 4 Graph illustrating global distribution of solar manufacturing market share from 1990 to 2010. Solar Background Document 4.pdf More Documents &...

251

Characterisation for some emission sources in CMB calculation for Mae Moh area, Thailand  

Science Journals Connector (OSTI)

Particulate samples of agricultural waste burning, straw burning, forest leaf burning, heavy duty truck emission, paved road dust, soil, agricultural soil, coal, electrostatic precipitator ash, and emission from stack power plant were collected from the Mae Moh area. Chemical compositions of sampling filters were analysed to determine the particulate matter source profiles. The analysis included ICP-MS for elemental compositions, ion chromatography for water soluble ions and CHNS/O for carbon species. In all biomass burning profiles organic carbon (OC) was higher during smouldering phase, while elemental carbon (EC) was higher during flaming phase. Results relating to biomass emission during flaming stage showed increase in K+. Organic and elemental carbons were the most abundant in biomass burning and truck exhaust. The abundance of EC was much lower, and the abundance of OC was much higher in biomass burning relative to truck exhaust emission. Al, K, Mg, Ca, and Fe were presented with high abundance in road dust, soil, coal, fly ash and stack samples. The differences in chemical compositions were not sufficient to distinguish geological material and fugitive dust sources. Fly ash profile differed from the others since OC and EC were not detected. Na and Zn were most abundant in stack samples. These findings served as a starting point for source contribution study. For future application of source apportionment using the CMB modelling technique, these source profiles should be appropriately grouped and selected to generate reliable outcomes.

A. Wangkiat; N.W. Harvey; S. Okamoto; S. Wangwongwatana; P. Rachdawong

2004-01-01T23:59:59.000Z

252

On the significance of power asymmetries in Planck CMB data at all scales  

E-Print Network (OSTI)

We perform an analysis of the CMB temperature data taken by the Planck satellite investigating if there is any significant deviation from cosmological isotropy. We look for differences between two opposite hemispheres with respect to particular directions, comparing with simulations. We apply a mask symmetrized in antipodal directions to avoid possible biases and smoothed on a 10' scale to avoid spurious extra power on small scales induced by sharp edges. We properly take into account of Doppler and aberration effects due to our peculiar velocity and of the anisotropy of the noise, since these effects induce a significant "hemispherical asymmetry". We are thus able to probe scales all the way to $\\ell = 2000$. After such treatment we find no evidence for significant hemispherical anomalies along any of the analyzed directions (i.e., deviations are less than 2$\\sigma$ in the full range of $\\ell$). Then we find results on a "dipolar modulation" of the the power spectrum of amplitude $A_{mod}$. Along the most as...

Quartin, Miguel

2014-01-01T23:59:59.000Z

253

APS USER TRAINING HISTORY Background  

NLE Websites -- All DOE Office Websites (Extended Search)

USER TRAINING HISTORY USER TRAINING HISTORY Background The User Program Division Director has delegated to the CATs the authority to authorize the conduct of experiments because the CATs have accepted responsibility for: * identifying and evaluating the hazards posed by the experiment, * specifying controls appropriate to the hazards, and * verifying that controls are in place. One form of hazard control frequently made mandatory by law and laboratory policy is worker knowledge. The accepted means of verifying that a worker has the required knowledge is ensuring that the worker has completed appropriate training. With CAT input, the APS has developed the APS User Training History. This web-based tool enables designated CAT personnel to examine data characterizing ES&H training courses

254

First Intrinsic Anisotropy Observations with the Cosmic Background Imager  

E-Print Network (OSTI)

We present the first results of observations of the intrinsic anisotropy of the cosmic microwave background radiation with the Cosmic Background Imager from a site at 5080 m altitude in northern Chile. Our observations show a sharp decrease in C_l in the range l=400 - 1500. The broadband amplitudes we have measured are deltaT(band) = 58.7 (-6.3, +7.7) microK for l = 603 (-166, +180) and 29.7 (-4.2, +4.8) microK for l = 1190 (-224, +261), where these are half-power widths in l. Such a decrease in power at high l is one of the fundamental predictions of the standard cosmological model, and these are the first observations which cover a broad enough l range to show this decrease in a single experiment. The C_l we have measured enable us to place limits on the density parameter, Omega(tot) = 0.7 (90% confidence).

S. Padin; J. K. Cartwright; B. S. Mason; T. J. Pearson; A. C. S. Readhead; M. C. Shepherd; J. Sievers; P. S. Udomprasert; W. L. Holzapfel; S. T. Myers; J. E. Carlstrom; E. M. Leitch; M. Joy; L. Bronfman; J. May

2000-12-11T23:59:59.000Z

255

Large-Angular-Scale Anisotropy in the Cosmic Background Radiation  

DOE R&D Accomplishments (OSTI)

We report the results of an extended series of airborne measurements of large-angular-scale anisotropy in the 3 K cosmic background radiation. Observations were carried out with a dual-antenna microwave radiometer operating at 33 GHz (.089 cm wavelength) flown on board a U-2 aircraft to 20 km altitude. In eleven flights, between December 1976 and May 1978, the radiometer measured differential intensity between pairs of directions distributed over most of the northern hemisphere with an rms sensitivity of 47 mK Hz{sup 1?}. The measurements how clear evidence of anisotropy that is readily interpreted as due to the solar motion relative to the sources of the radiation. The anisotropy is well fit by a first order spherical harmonic of amplitude 360{+ or -}50km sec{sup -1} toward the direction 11.2{+ or -}0.5 hours of right ascension and 19 {+ or -}8 degrees declination. A simultaneous fit to a combined hypotheses of dipole and quadrupole angular distributions places a 1 mK limit on the amplitude of most components of quadrupole anisotropy with 90% confidence. Additional analysis places a 0.5 mK limit on uncorrelated fluctuations (sky-roughness) in the 3 K background on an angular scale of the antenna beam width, about 7 degrees.

Gorenstein, M. V.; Smoot, G. F.

1980-05-00T23:59:59.000Z

256

Phase 2 microwave concrete decontamination results  

SciTech Connect

The authors report on the results of the second phase of a four-phase program at Oak Ridge National Laboratory to develop a system to decontaminate concrete using microwave energy. The microwave energy is directed at the concrete surface through the use of an optimized wave guide antenna, or applicator, and this energy rapidly heats the free water present in the interstitial spaces of the concrete matrix. The resulting steam pressure causes the surface to burst in much the same way popcorn pops in a home microwave oven. Each steam explosion removes several square centimeters of concrete surface that are collected by a highly integrated wave guide and vacuum system. The authors call this process the microwave concrete decontamination, or MCD, process. In the first phase of the program the principle of microwaves concrete removal concrete surfaces was demonstrated. In these experiments, concrete slabs were placed on a translator and moved beneath a stationary microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from concrete floors. Area and volume concrete removal rates of 10.4 cm{sup 2}/s and 4.9 cm{sup 3}/S, respectively, at 18 GHz were demonstrated. These rates are more than double those obtained in Phase 1 of the program. Deeper contamination can be removed by using a longer residence time under the applicator to create multiple explosions in the same area or by taking multiple passes over previously removed areas. Both techniques have been successfully demonstrated. Small test sections of painted and oil-soaked concrete have also been removed in a single pass. Concrete with embedded metal anchors on the surface has also been removed, although with some increased variability of removal depth. Microwave leakage should not pose any operational hazard to personnel, since the observed leakage was much less than the regulatory standard.

White, T.L.; Foster, D. Jr.; Wilson, C.T.; Schaich, C.R.

1995-04-01T23:59:59.000Z

257

Degree-scale anomalies in the CMB: Localizing the first peak dip to a small patch of the north ecliptic sky  

SciTech Connect

Noticeable deviations from the prediction of the fiducial lambda cold dark matter cosmology are found in the angular power spectrum of the cosmic microwave background. Besides large-angle anomalies, the WMAP first year data revealed a dip in the power spectrum at l{approx}200, which seemed to disappear in the third year and subsequent angular power spectra. Using the WMAP single first, third, and fifth year data as well as the total 5 yr coadded data, we study the intensity and spatial distribution of this feature in order to unveil its origin and its implications for the cosmological parameters. We show that in the 5 yr coadded WMAP data release there is a suppression of the first Doppler peak in a region near the north ecliptic pole at a significance level between 99% and 96% depending on the weighting scheme that is considered.

Yoho, Amanda [CERCA, Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106-7079 (United States); Ferrer, Francesc [Physics Department and McDonnell Center for the Space Sciences, Washington University, St Louis, Missouri 63130 (United States); Starkman, Glenn D. [CERCA/ISO, Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106-7079 (United States)

2011-04-15T23:59:59.000Z

258

Effects of Microwave Radiation on Oil Recovery  

Science Journals Connector (OSTI)

A variety of oil recovery methods have been developed and applied to mature and depleted reservoirs in order to improve the efficiency. Microwave radiation oil recovery method is a relatively new method and has been of great interest in the recent years. Crude oil is typically co?mingled with suspended solids and water. To increase oil recovery it is necessary to remove these components. The separation of oil from water and solids using gravitational settling methods is typically incomplete. Oil?in?water and oil?water?solid emulsions can be demulsified and separated into their individual layers by microwave radiation. The data also show that microwave separation is faster than gravity separation and can be faster than conventional heating at many conditions. After separation of emulsion into water and oil layers water can be discharged and oil is collected. High?frequency microwave recycling process can recover oil and gases from oil shale residual oil drill cuttings tar sands oil contaminated dredge/sediments tires and plastics with significantly greater yields and lower costs than are available utilizing existing known technologies. This process is environmentally friendly fuel?generating recycler to reduce waste cut emissions and save energy. This paper presents a critical review of Microwave radiation method for oil recovery.

2011-01-01T23:59:59.000Z

259

Microwave vs. Electric Kettle: Which Appliance Is in Hot Water...  

Energy Savers (EERE)

Microwave vs. Electric Kettle: Which Appliance Is in Hot Water in EnergyFaceoff Round 4? Microwave vs. Electric Kettle: Which Appliance Is in Hot Water in EnergyFaceoff Round 4?...

260

Global estimation of precipitation using opaque microwave bands  

E-Print Network (OSTI)

This thesis describes the use of opaque microwave bands for global estimation of precipitation rate. An algorithm was developed for estimating instantaneous precipitation rate for the Advanced Microwave Sounding Unit (AMSU) ...

Chen, Frederick Wey-Min, 1975-

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

DarkLight radiation backgrounds  

SciTech Connect

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-on, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW CW beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, field emission inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation.

Kalantarians, N. [Department of Physics, Hampton University, Hampton VA 23668 (United States); Collaboration: DarkLight Collaboration

2013-11-07T23:59:59.000Z

262

DarkLight radiation backgrounds  

SciTech Connect

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-on, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW CW beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, field emission inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation.

Kalantarians, Narbe [University of Texas

2013-11-01T23:59:59.000Z

263

Microwave off-gas treatment apparatus and process  

DOE Patents (OSTI)

The invention discloses a microwave off-gas system in which microwave energy is used to treat gaseous waste. A treatment chamber is used to remediate off-gases from an emission source by passing the off-gases through a susceptor matrix, the matrix being exposed to microwave radiation. The microwave radiation and elevated temperatures within the combustion chamber provide for significant reductions in the qualitative and quantitative emissions of the gas waste stream.

Schulz, Rebecca L. (Aiken, SC); Clark, David E. (Gainesville, FL); Wicks, George G. (North Aiken, SC)

2003-01-01T23:59:59.000Z

264

Microwave accelerator E-beam pumped laser  

DOE Patents (OSTI)

A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

Brau, Charles A. (Los Alamos, NM); Stein, William E. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM)

1980-01-01T23:59:59.000Z

265

Map-making in small field modulated CMB polarisation experiments: approximating the maximum-likelihood method  

E-Print Network (OSTI)

Map-making presents a significant computational challenge to the next generation of kilopixel CMB polarisation experiments. Years worth of time ordered data (TOD) from thousands of detectors will need to be compressed into maps of the T, Q and U Stokes parameters. Fundamental to the science goal of these experiments, the observation of B-modes, is the ability to control noise and systematics. In this paper, we consider an alternative to the maximum-likelihood method, called destriping, where the noise is modelled as a set of discrete offset functions and then subtracted from the time-stream. We compare our destriping code (Descart: the DEStriping CARTographer) to a full maximum-likelihood map-maker, applying them to 200 Monte-Carlo simulations of time-ordered data from a ground based, partial-sky polarisation modulation experiment. In these simulations, the noise is dominated by either detector or atmospheric 1/f noise. Using prior information of the power spectrum of this noise, we produce destriped maps of T, Q and U which are negligibly different from optimal. The method does not filter the signal or bias the E or B-mode power spectra. Depending on the length of the destriping baseline, the method delivers between 5 and 22 times improvement in computation time over the maximum-likelihood algorithm. We find that, for the specific case of single detector maps, it is essential to destripe the atmospheric 1/f in order to detect B-modes, even though the Q and U signals are modulated by a half-wave plate spinning at 5-Hz.

D. Sutton; B. R. Johnson; M. L. Brown; P. Cabella; P. G. Ferreira; K. M. Smith

2008-07-23T23:59:59.000Z

266

Methods for microwave heat treatment of manufactured components  

DOE Patents (OSTI)

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Ripley, Edward B. (Knoxville, TN)

2010-08-03T23:59:59.000Z

267

Ground-Based Microwave Radiometer Measurements  

NLE Websites -- All DOE Office Websites (Extended Search)

Ground-Based Microwave Radiometer Measurements Ground-Based Microwave Radiometer Measurements and Radiosonde Comparisons During the WVIOP2000 Field Experiment D. Cimini University of L'Aquila L'Aquil, Italy E. R. Westwater Cooperative Institute for Research in the Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Y. Han Science System Applications National Aeronautics Space Administration Goddard Space Flight Center Greenbelt, Maryland S. Keihm Jet Propulsion Laboratory California Institute of Technology Pasadena, California Introduction During September to October 2000, a water vapor intensive operational period (WVIOP) was conducted at the Atmospheric Radiation Measurement (ARM) Program's Southern Great Plains (SGP) Cloud and

268

Carbon monoxide line emission as a CMB foreground: tomography of the star-forming universe with different spectral resolutions  

E-Print Network (OSTI)

The rotational lines of carbon monoxide and the fine structure lines of CII and of the most abundant metals, emitted during the epoch of enhanced star formation in the universe, are redshifted in the frequency channels where the present-day and future CMB experiments are sensitive. We estimate the contribution to the CMB angular power spectrum by the emission in such lines in merging star-forming galaxies. We used the Lacey-Cole approach to characterize the distribution of the merging halos, together with a parametrization for the star formation rate in each of them. Using observational data from a sample of local, low-redshift, and high-redshift objects, we calibrated the luminosity in each line as a function of the star formation rate. We show that the correlation term arising from CO line emission is a significant source of foreground for CMB in a broad range of frequencies (in particular in the 20-60 GHz band) and for 1000

Mattia Righi; Carlos Hernandez-Monteagudo; Rashid Sunyaev

2008-07-24T23:59:59.000Z

269

International Conference on Microwave and High Frequency Heating Nottingham, UK, September 2013 Scaling Up Reactors for Microwave-Assisted  

E-Print Network (OSTI)

2013 316 Scaling Up Reactors for Microwave-Assisted Chemistry via ANN Optimization Andrew O. Holmesa by demonstrating that a particular microwave reactor can be designed with the help of computer optimization optimization technique to a microwave reactor. This technique is used here to optimize the geometry of a system

Yakovlev, Vadim

270

A SEARCH FOR CONCENTRIC CIRCLES IN THE 7 YEAR WILKINSON MICROWAVE ANISOTROPY PROBE TEMPERATURE SKY MAPS  

SciTech Connect

In this Letter, we search for concentric circles with low variance in cosmic microwave background sky maps. The detection of such circles would hint at new physics beyond the current cosmological concordance model, which states that the universe is isotropic and homogeneous, and filled with Gaussian fluctuations. We first describe a set of methods designed to detect such circles, based on matched filters and {chi}{sup 2} statistics, and then apply these methods to the best current publicly available data, the 7 year Wilkinson Microwave Anisotropy Probe (WMAP) temperature sky maps. We compare the observations with an ensemble of 1000 Gaussian {Lambda}CDM simulations. Based on these tests, we conclude that the WMAP sky maps are fully compatible with the Gaussian and isotropic hypothesis as measured by low-variance ring statistics.

Wehus, I. K. [Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Eriksen, H. K., E-mail: i.k.wehus@fys.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

2011-06-01T23:59:59.000Z

271

Modeling and characterization of a cantilever-based near-field scanning microwave impedance microscope  

Science Journals Connector (OSTI)

This paper presents a detailed modeling and characterization of a microfabricated cantilever-based scanning microwave probe with separated excitation and sensing electrodes. Using finite-element analysis we model the tip-sample interaction as small impedance changes between the tip electrode and the ground at our working frequencies near 1 GHz . The equivalent lumped elements of the cantilever can be determined by transmission line simulation of the matching network which routes the cantilever signals to 50 ? feed lines. In the microwave electronics the background common-mode signal is canceled before the amplifier stage so that high sensitivity (below 1 aF capacitance changes) is obtained. Experimental characterization of the microwavemicroscope was performed on ion-implanted Si wafers and patterned semiconductor samples. Pure electrical or topographical signals can be obtained from different reflection modes of the probe.

K. Lai; W. Kundhikanjana; M. Kelly; Z. X. Shen

2008-01-01T23:59:59.000Z

272

Optimized ECR plasma apparatus with varied microwave window thickness  

DOE Patents (OSTI)

The present invention describes a technique to control the radial profile of microwave power in an ECR plasma discharge. In order to provide for a uniform plasma density to a specimen, uniform energy absorption by the plasma is desired. By controlling the radial profile of the microwave power transmitted through the microwave window of a reactor, the profile of the transmitted energy to the plasma can be controlled in order to have uniform energy absorption by the plasma. An advantage of controlling the profile using the window transmission characteristics is that variations to the radial profile of microwave power can be made without changing the microwave coupler or reactor design. 9 figs.

Berry, L.A.

1995-11-14T23:59:59.000Z

273

Gravitational clustering in Static and Expanding Backgrounds  

E-Print Network (OSTI)

A brief summary of several topics in the study of gravitational many body problem is given. The discussion covers both static backgrounds (applicable to astrophysical systems) as well as clustering in an expanding background (relevant for cosmology)

T. Padmanabhan

2003-08-28T23:59:59.000Z

274

Network Requirements Workshop - Documents and Background Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Requirements Reviews Network Requirements Reviews Documents and Background Materials Science Engagement Move your data Programs & Workshops Science...

275

Microwave Plasma Sources for Gas Processing  

SciTech Connect

In this paper atmospheric pressure microwave discharge methods and devices used for producing the non-thermal plasmas for processing of gases are presented. The main part of the paper concerns the microwave plasma sources (MPSs) for environmental protection applications. A few types of the MPSs, i.e. waveguide-based surface wave sustained MPS, coaxial-line-based and waveguide-based nozzle-type MPSs, waveguide-based nozzleless cylinder-type MPS and MPS for microdischarges are presented. Also, results of the laboratory experiments on the plasma processing of several highly-concentrated (up to several tens percent) volatile organic compounds (VOCs), including Freon-type refrigerants, in the moderate (200-400 W) waveguide-based nozzle-type MPS (2.45 GHz) are presented. The results showed that the microwave discharge plasma fully decomposed the VOCs at relatively low energy cost. The energy efficiency of VOCs decomposition reached 1000 g/kWh. This suggests that the microwave discharge plasma can be a useful tool for environmental protection applications. In this paper also results of the use of the waveguide-based nozzleless cylinder-type MPS to methane reforming into hydrogen are presented.

Mizeraczyk, J. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland); Department of Marine Electronics, Gdynia Martime University, Morska 83, 81-225 Gdynia (Poland); Jasinski, M.; Dors, M.; Zakrzewski, Z. [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland)

2008-03-19T23:59:59.000Z

276

Analysis of Microwave Propagation In Plasma  

E-Print Network (OSTI)

Analysis of Microwave Propagation In Plasma Elaine Chung Advisor: Dr. John Rodgers #12;Plasma OverviewPlasma Overview · Plasma ­ ionized gas htt[p://www.noaa.gov http://www.photoeverywhere.co.uk http://sohowww.nascom.nasa.gov/ #12;Experimental Plasma · Formed by collisional excitation of gas in an electric field Electrode Non

Anlage, Steven

277

Environmental assessment: South microwave communication facilities  

SciTech Connect

Western Area Power Administration (Western) is proposing to construct, operate, and maintain eight microwave repeater stations in southwestern Colorado, southeastern Utah, and northern Arizona, in order to meet the minimum fade criteria established by the Western Systems Coordinating Council (WSCC) for the operation and protection of electric power systems. The proposed microwave facilities would increase the reliability of communication. This environmental assessment (EA) describes the existing environmental conditions and the impacts from construction of the eight microwave communication facilities. The EA was prepared in compliance with the National Environmental Policy Act of 1969, the Council on Environmental Quality Regulations (40 CFR 1500-1508), and the Department of Energy Guidelines (52 FR 47662, December 15, 1987). The proposed project would consist of constructing eight microwave facilities, each of which would include a self-supported lattice tower, an equipment building, a propane tank, distribution lines to provide electric power to the sites, and access roads to the sites. The facilities would be constructed in San Miguel and Montezuma Counties in Colorado, San Juan County, Utah, and Navajo, Apache, Coconino, and Yavapai Counties in Arizona. 20 refs., 2 figs., 2 tabs.

Not Available

1989-06-01T23:59:59.000Z

278

Risk Estimation; Background Radiation (Natural and Artificial )  

E-Print Network (OSTI)

-threshold mode estimate the response at lower doses. · The Committee on Biological Effects of Ionizing RadiationModule 9 Risk Estimation; Background Radiation (Natural and Artificial ) · sources of background radiation · various risk models. · estimating risk and on the sources of background radiation, both

Massey, Thomas N.

279

Results from the First Flight of BAM  

E-Print Network (OSTI)

A new instrument, BAM (Balloon-borne Anisotropy Measurement), designed to measure cosmic microwave background (CMB) anisotropy at medium angular scales was flown for the first time in July of 1995. BAM is unique in that it uses a cryogenic differential Fourier transform spectrometer coupled to a lightweight off-axis telescope. The very successful first flight of BAM demonstrates the potential of the instrument for obtaining high quality CMB anisotropy data.

G. S. Tucker; H. P. Gush; M. Halpern; W. Towlson

1996-09-17T23:59:59.000Z

280

hepreqrev.pptx  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Background Microwave Background Data Analysis Julian Borrill Computational Cosmology Center, LBNL Space Sciences Laboratory, UCB A History Of The Universe Planck CMB Science * Past: - Existence => evidence of Big Bang over Steady State - Temperature anisotropies => fundamental parameters of cosmology, complementary constraints (SN1a) * Present: - Temperature & E-mode polarization anisotropies => precision cosmology, complementary constraints (DE) * Future: - B-mode polarization anisotropies => measurement of lensing potential, evidence of & constraints on Inflation 2 Nobel Prizes awarded, 1 supported, 1 anticipated! The CMB Data Challenge * Extracting fainter signals (polarization, high resolution) from the data requires: - larger data volumes to provide higher signal-to-noise.

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Inflation from D3-brane motion in the background of D5-branes  

Science Journals Connector (OSTI)

We study inflation arising from the motion of a Bogomol’nyi-Prasad-Sommerfield D3-brane in the background of a stack of k parallel D5-branes. There are two scalar fields in this setup: (i) the radion field R, a real scalar field, and (ii) a complex tachyonic scalar field ? living on the world volume of the open string stretched between the D3 and D5 branes. We find that inflation is realized by the potential of the radion field, which satisfies observational constraints coming from the cosmic microwave background. After the radion becomes of the order of the string length scale ls, the dynamics is governed by the potential of the complex scalar field. Since this field has a standard kinematic term, reheating can be successfully realized by the mechanism of tachyonic preheating with spontaneous symmetry breaking.

Sudhakar Panda; M. Sami; Shinji Tsujikawa; John Ward

2006-04-07T23:59:59.000Z

282

TEC Working Group Background | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

TEC Working Group Background TEC Working Group Background TEC Working Group Background Through the TEC/WG, DOE interacted with representatives of organizations at the state, tribal, and local levels to obtain input for program needs assessment, development and management, and to enhance their capability to carry out transportation emergency preparedness and safety activities specifically related to radioactive materials shipments. TEC membership included representatives from national, state, tribal and local government organizations, labor, industry and professional groups. Members meet semiannually to participate in plenary sessions, breakout work sessions, and in more specialized Topic Groups. To learn more about the history and background of TEC, please see the following documents:

283

TEC Working Group Background | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Background Background TEC Working Group Background Through the TEC/WG, DOE interacted with representatives of organizations at the state, tribal, and local levels to obtain input for program needs assessment, development and management, and to enhance their capability to carry out transportation emergency preparedness and safety activities specifically related to radioactive materials shipments. TEC membership included representatives from national, state, tribal and local government organizations, labor, industry and professional groups. Members meet semiannually to participate in plenary sessions, breakout work sessions, and in more specialized Topic Groups. To learn more about the history and background of TEC, please see the following documents: TEC Charter TEC Work Plan

284

LOW INCOME ENERGY EFFICIENCY PROGRAM OVERVIEW Background  

NLE Websites -- All DOE Office Websites (Extended Search)

314 LOW INCOME ENERGY EFFICIENCY PROGRAM OVERVIEW Background BPA's low income program began in 1980, serving the states of Oregon, Montana, Idaho, and Washington. Over time the...

285

Lighting Choices - White Background | Department of Energy  

Energy Savers (EERE)

the new energy standards that take effect from 2012-2014. allbulbshiresweb.eps More Documents & Publications Lighting Choices - White Background Lighting Choices...

286

On the mechanism of electromagnetic microwave absorption in superfluid helium  

SciTech Connect

In experiments on electromagnetic (EM) wave absorption in the microwave range in superfluid (SF) helium [1-3], a narrow EM field absorption line with a width on the order of (20-200) kHz was observed against the background of a wide absorption band with a width of 30-40 GHz at frequencies f{sub 0} Almost-Equal-To 110-180 GHz corresponding to the roton gap energy {Delta}{sub r}(T) in the temperature range 1.4-2.2 K. Using the so-called flexoelectric mechanism of polarization of helium atoms ({sup 4}He) in the presence of density gradients in SF helium (HeII), we show that nonresonance microwave absorption in the frequency range 170-200 GHz can be due to the existence of time-varying local density gradients produced by roton excitations in the bulk HeII. The absorption bandwidth is determined by the roton-roton scattering time in an equilibrium Boltzmann gas of rotons, which is t{sub r-r} Almost-Equal-To 3.4 Multiplication-Sign 10{sup -11} s at T = 1.4 K and decreases upon heating. We propose that the anomalously narrow microwave resonance absorption line in HeII at the roton frequency f{sub 0}(T) = {Delta}r(T)/2{pi}h appears due to the following two factors: (i) the discrete structure of the spectrum of the surface EM resonator modes in the form of a periodic sequence of narrow peaks and (ii) the presence of a stationary dipole layer in HeII near the resonator surface, which forms due to polarization of {sup 4}He atoms under the action of the density gradient associated with the vanishing of the density of the SF component at the solid wall. For this reason, the relaxation of nonequilibrium rotons generated in such a surface dipole layer is strongly suppressed, and the shape and width of the microwave resonance absorption line are determined by the roton density of states, which has a sharp peak at the edge of the roton gap in the case of weak dissipation. The effective dipole moments of rotons in the dipole layer can be directed either along or across the normal to the resonator surface, which explains the experimentally observed symmetric doublet splitting of the resonance absorption line in an external dc electric field perpendicular to the resonator surface. We show that negative absorption (induced emission) of EM field quanta observed after triggering a Kapitza 'heat gun' occurs when the occupation numbers for roton states due to 'pumping' of rotons exceed the occupation numbers of EM field photons in the resonator.

Pashitskii, E. A., E-mail: pashitsk@iop.kiev.ua; Pentegov, V. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine)

2012-08-15T23:59:59.000Z

287

Ground-based Microwave Cloud Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Cloud Tomography Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation 3/30/2009 ARM RPWG 3 Typical climate model - Cloud fraction & mean water content - Horizontally uniform clouds, no side radiation - Assumption on overlap Courtesy of Bernhard Mayer Cloud structure important to radiation - Cumulus (Benner & Evans 2001, Pincus et al. 2005), deep convection (DiGiuseppe &

288

Nonlinear multiferroic phase shifters for microwave frequencies  

SciTech Connect

A nonlinear microwave phase shifter based on a planar multiferroic composite has been studied. The multiferroic structure is fabricated in the form of a bilayer consisting of yttrium iron garnet and barium strontium titanate. The principle of operation of the device is based on the linear and nonlinear control of the phase shift of the hybrid spin-electromagnetic waves propagating in the bilayer. The linear control is realized with magnetic and electric fields. The nonlinear control is provided by the input power of microwave signal. The device showed a nonlinear phase shift up to 250°, electric field induced phase shift up to 330°, and magnetic field induced phase shift of more than 180°.

Ustinov, Alexey B.; Kalinikos, Boris A. [Department of Physical Electronics and Technology, St. Petersburg Electrotechnical University, St. Petersburg 197376 (Russian Federation); Srinivasan, G. [Department of Physics, Oakland University, Rochester, Michigan 48309 (United States)

2014-02-03T23:59:59.000Z

289

Hybrid Microwave-Cavity Heat Engine  

E-Print Network (OSTI)

We propose and analyze the use of hybrid microwave cavities as quantum heat engines. A possible realization consists of two macroscopically separated quantum dot conductors coupled capacitively to the fundamental mode of a microwave cavity. We demonstrate that an electrical current can be induced in one conductor through cavity-mediated processes by heating up the other conductor. The heat engine can reach Carnot efficiency with optimal conversion of heat to work. When the system delivers the maximum power, the efficiency can be a large fraction of the Carnot efficiency. The heat engine functions even with moderate electronic relaxation and dephasing in the quantum dots. We provide detailed estimates for the electrical current and output power using realistic parameters.

Christian Bergenfeldt; Peter Samuelsson; Björn Sothmann; Christian Flindt; Markus Büttiker

2014-02-27T23:59:59.000Z

290

A container for heat treating materials in microwave ovens  

DOE Patents (OSTI)

The efficiency of a microwave oven of a conventional two-source configuration and energy level is increased by providing the oven with a container for housing a refractory material to be treated. The container is formed to top and bottom walls transparent to microwaves while the sidewalls, in a circular configuration, are formed of a nonmetallic material opaque to microwave radiation for reflecting the radiation penetrating the top and bottom walls radially inwardly into the center of the container wherein a casket of heat-insulating material is provided for housing the material to be heat treated. The reflection of the microwave radiation from the sidewalls increases the concentration of the microwaves upon the material being heat treated while the concentration of the microwaves upon the material being heat treated while the casket retains the heat to permit the heating of the material to a substantially higher temperature than achievable in the oven without the container.

Holcombe, C.E.; Dykes, N.L.; Kimrey, H.D. Jr.; Mills, J.E.

1988-01-26T23:59:59.000Z

291

Cavity Microwave Searches for Cosmological Axions  

SciTech Connect

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.

Carosi, G; van Bibber, K

2007-01-22T23:59:59.000Z

292

Joining of thermoplastic substrates by microwaves  

DOE Patents (OSTI)

A method for joining two or more items having surfaces of thermoplastic material includes the steps of depositing an electrically-conductive material upon the thermoplastic surface of at least one of the items, and then placing the other of the two items adjacent the one item so that the deposited material is in intimate contact with the surfaces of both the one and the other items. The deposited material and the thermoplastic surfaces contacted thereby are then exposed to microwave radiation so that the thermoplastic surfaces in contact with the deposited material melt, and then pressure is applied to the two items so that the melted thermoplastic surfaces fuse to one another. Upon discontinuance of the exposure to the microwave energy, and after permitting the thermoplastic surfaces to cool from the melted condition, the two items are joined together by the fused thermoplastic surfaces. The deposited material has a thickness which is preferably no greater than a skin depth, .delta..sub.s, which is related to the frequency of the microwave radiation and characteristics of the deposited material in accordance with an equation.

Paulauskas, Felix L. (Oak Ridge, TN); Meek, Thomas T. (Knoxville, TN)

1997-01-01T23:59:59.000Z

293

Gas Chromatography—Microwave-Induced Plasma for the Determination of Halogenated Hydrocarbons  

Science Journals Connector (OSTI)

......microwave-induced plasma detector. The...generator (2450 MHz frequency) was...microwave-induced plasma in helium at atmospheric pressure as an...compounds with atmospheric pressure helium microwave induced plasma-atomic emission......

M.M. Abdillahi

1990-12-01T23:59:59.000Z

294

E-Print Network 3.0 - argon microwave plasma Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Vortex Stabilization of Microwave PlasmaMicrowave... Plasma a b 2 1 3 5 4 6 7 1- quartz tube of microwave plasma torch; 2 -original tangential gas feeder; 3... Numerical...

295

Probing Dark Energy with Neutrino Number  

E-Print Network (OSTI)

From measurements of the cosmic microwave background (CMB), the effective number of neutrino is found to be close to the standard model value Neff = 3.046 for the \\LambdaCDM cosmology. One can obtain the same CMB angular power spectrum as that of \\LambdaCDM for the different value of Neff by using the different dark energy model (i.e. for the different value of w). This degeneracy between Neff and w in CMB can be broken from future galaxy survey using the matter power spectrum.

Seokcheon Lee

2014-10-06T23:59:59.000Z

296

Probing Dark Energy with Neutrino Number  

E-Print Network (OSTI)

From measurements of the cosmic microwave background (CMB), the effective number of neutrino is found to be close to the standard model value Neff = 3.046 for the \\LambdaCDM cosmology. One can obtain the same CMB angular power spectrum as that of \\LambdaCDM for the different value of Neff by using the different dark energy model (i.e. for the different value of w). This degeneracy between Neff and w in CMB can be broken from future galaxy survey using the matter power spectrum.

Lee, Seokcheon

2014-01-01T23:59:59.000Z

297

Atmospheric muon background in the ANTARES detector  

E-Print Network (OSTI)

An evaluation of the background due to atmospheric muons in the ANTARES high energy neutrino telescope is presented. Two different codes for atmospheric shower simulation have been used. Results from comparisons between these codes at sea level and detector level are presented. The first results on the capability of ANTARES to reject this class of background are given.

S. Cecchini; E. Korolkova; A. Margiotta; L. Thompson

2005-10-28T23:59:59.000Z

298

Product Standards for Microwaves (Japan) | Open Energy Information  

Open Energy Info (EERE)

Product Standards for Microwaves (Japan) Product Standards for Microwaves (Japan) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Product Standards for Microwaves (Japan) Focus Area: Appliances & Equipment Topics: Policy Impacts Website: www.eccj.or.jp/top_runner/pdf/tr_microwaveoven.pdf Equivalent URI: cleanenergysolutions.org/content/product-standards-microwaves-japan Language: English Policies: "Deployment Programs,Regulations" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Industry Codes & Standards Regulations: Appliance & Equipment Standards and Required Labeling This Energy Conservation Center Japan (ECCJ) document was created as a guide in response to its newly established set of standards and labelling

299

Microwave heating for adsorbents regeneration and oil sands coke activation.  

E-Print Network (OSTI)

??Microwave heating has unique advantages compared to convection-radiation heating methods including fast heating rate and selective heating of objects. This thesis studied two applications of… (more)

Chen, Heng

2010-01-01T23:59:59.000Z

300

Posters Preliminary Analysis of Ground-Based Microwave and Infrared...  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Posters Preliminary Analysis of Ground-Based Microwave and Infrared Radiance Observations During the Pilot Radiation OBservation Experiment E. R. Westwater, Y. Han, J. H....

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Microwave-Assisted Polymerizations: Recent Status and Future Perspectives  

Science Journals Connector (OSTI)

Microwave heating is frequently used in the synthesis of polymers owing to the precise temperature and pressure control when using monomodal microwave synthesizer. ... Nguyen et al. investigated the homopolymerization of vinylcyclicsilazanes as well as their ability to be used in block copolymerizations with St.(19) The usage of microwave heating allowed the synthesis of higher molar mass polyvinylsilazanes (H-PVSZ) with an excellent control over the polymerization compared to conventional heating, which was attributed to the superior dielectric properties of the PVSZ mixture obtained by microwave irradiation. ... Time- and energy-consuming synthetic pathways that usually involve the use of volatile, flammable or toxic org. ...

Kristian Kempe; C. Remzi Becer; Ulrich S. Schubert

2011-07-13T23:59:59.000Z

302

Going to the End of the Earth to Learn About the Beginning of the Universe  

SciTech Connect

The cosmic microwave background (CMB) is revolutionizing our understanding of the Universe. The CMB is the most powerful piece of evidence that we live in a geometrically flat Universe, dominated by cold dark matter and dark energy. Even with this basic cosmological model established, there are still many outstanding questions: What is dark energy? What is the sum of the neutrino masses? Are there unknown particle species that we can detect cosmologically? Did Inflation happen? I will review the history of measurements of the CMB; what have they told us so far, and how the South Pole has developed into the premier site for observations of the CMB. Finally, I will discuss new measurements and cosmological results from the South Pole Telescope, a 10-meter diameter telescope that is making precision measurements of the temperature and polarization anisotropy of the CMB.

Benson, Bradford [University of Chicago

2013-02-06T23:59:59.000Z

303

Minimal Microwave Anisotropy from Perturbations Induced at Late Times  

E-Print Network (OSTI)

Aside from primordial gravitational instability of the cosmological fluid, various mechanisms have been proposed to generate large-scale structure at relatively late times, including, e.g., ``late-time'' cosmological phase transitions. In these scenarios, it is envisioned that the universe is nearly homogeneous at the time of last scattering and that perturbations grow rapidly sometime after the primordial plasma recombines. On this basis, it was suggested that large inhomogeneities could be generated while leaving relatively little imprint on the cosmic microwave background (MBR) anisotropy. In this paper, we calculate the minimal anisotropies possible in any ``late-time'' scenario for structure formation, given the level of inhomogeneity observed at present. Since the growth of the inhomogeneity involves time-varying gravitational fields, these scenarios inevitably generate significant MBR anisotropy via the Sachs-Wolfe effect. Moreover, we show that the large-angle MBR anisotropy produced by the rapid post-recombination growth of inhomogeneity is generally greater than that produced by the same inhomogeneity grown via gravitational instability. In ``realistic'' scenarios one can decrease the anisotropy compared to models with primordial adiabatic fluctuations, but only on very small angular scales. The value of any particular measure of the anisotropy can be made small in late-time models, but only by making the time-dependence of the gravitational field sufficiently ``pathological''.

Andrew H. Jaffe; Albert Stebbins; Joshua A. Frieman

1993-01-21T23:59:59.000Z

304

E-Print Network 3.0 - active microwave medium Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

MA: Artech House, 1981... . 41 F. Ulaby, R. Moore, and A. K. Fung, Microwave Remote Sensing: Active and Passive, vol. 3. Norwood... Sat Passive Microwave Polarimetric...

305

E-Print Network 3.0 - analogue microwave photonics Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineering ; Materials Science 6 Abstract--A novel approach to generating a frequency-tunable microwave or sub-terahertz wave based on time-delayed Summary: , microwave...

306

E-Print Network 3.0 - aura microwave limb Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

measured by the Aura Microwave Limb Sounder (MLS) version 2... of the greenhouse effect. Nature, 342, 758-761. Read, W. G., and Coauthors, 2007: Aura Microwave Limb...

307

Background field method as a canonical transformation  

Science Journals Connector (OSTI)

We construct explicitly the canonical transformation which controls the full dependence (local and nonlocal) of the vertex functional of a Yang-Mills theory on a background field. After showing that the canonical transformation found is nothing but a direct field-theoretic generalization of the Lie transform of classical analytical mechanics, we comment on a number of possible applications, and, in particular, the nonperturbative implementation of the background field method on the lattice, the background field formulation of the two-particle irreducible formalism, and, finally, the formulation of the Schwinger-Dyson series in the presence of topologically nontrivial configurations.

D. Binosi and A. Quadri

2012-06-21T23:59:59.000Z

308

Background considerations for SuperCDMS  

SciTech Connect

Rejection and protection from background is a key issue for the next generation SuperCDMS SNOLAB experiment that will have a cross-section sensitivity of better than 8 × 10{sup ?46} cm{sup 2} for spin-independent WIMP-nucleon interactions. This paper presents the details of the methods used to reject electromagnetic backgrounds using the new iZIP detectors that are currently operated in the Soudan Underground Laboratory, MN and the methods the collaboration is investigating to protect against neutron background in the next generation SuperCDMS experiment.

Cooley, J. [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States)] [Department of Physics, Southern Methodist University, Dallas, TX 75275 (United States); Collaboration: SuperCDMS Collaboration

2013-08-08T23:59:59.000Z

309

LOW INCOME ENERGY EFFICIENCY PROGRAM OVERVIEW Background  

NLE Websites -- All DOE Office Websites (Extended Search)

LOW INCOME ENERGY EFFICIENCY PROGRAM OVERVIEW Background BPA's low income program began in in the mid-80s, serving the states of Oregon, Montana, Idaho, and Washington. Over time...

310

Environmental Permit Application Background Statement (Delaware)  

Energy.gov (U.S. Department of Energy (DOE))

The purpose of Chapter 79 of Delaware Title 7 is to ensure that the State has adequate information about the background of applicants or regulated parties for the purposes of processing permits and...

311

Background Knowledge, Category Labels, and Similarity Judgment  

E-Print Network (OSTI)

are more special than shared physical features. The goal of this dissertation is to provide evidence that complements these conflicting views. I suggest that the role of labels varies depending on the background knowledge: types of categories (living things...

Yu, Na-Yung

2011-10-21T23:59:59.000Z

312

Microsoft Word - Appendix A_Background.doc  

Office of Legacy Management (LM)

Background Information, Remedial Action Histories, Background Information, Remedial Action Histories, Present Site Conditions U.S. Department of Energy Weldon Spring Site LTS&M Plan July 2005 Doc. No. S0079000 Page A-iii Contents A1.1 Location and Property Ownership ................................................................................1 A1.2 Physiography and Topography.....................................................................................4 A1.3 Hydrogeology ...............................................................................................................5 A1.3.1 Regional ...........................................................................................................5 A1.3.2 Chemical Plant .................................................................................................5

313

Fractal generation of textures and backgrounds  

E-Print Network (OSTI)

FRACTAL GENERATION OF TEXTURES AND BACKGROUNDS A Thesis by KEVIN DUANE REUTER Subtnitted to the Oflice of Graduate Studies of Texas A&M University in partial fulfilhnent of the requirements for the degree of MASTER OF SCIENCE August 1999... Major Subject; Visualization Sciences FRACTAL GENERATION OF TEXTURES AND BACKGROUNDS A Thesis by KEVIN DUANE REUTER Submitted to Texas ARM University in partial fulfilhnent of the requirements for the degree of MASTER OF SCIENCE Approved...

Reuter, Kevin Duane

2012-06-07T23:59:59.000Z

314

Estimating radiological background using imaging spectroscopy  

SciTech Connect

Optical imaging spectroscopy is investigated as a method to estimate radiological background by spectral identification of soils, sediments, rocks, minerals and building materials derived from natural materials and assigning tabulated radiological emission values to these materials. Radiological airborne surveys are undertaken by local, state and federal agencies to identify the presence of radiological materials out of regulatory compliance. Detection performance in such surveys is determined by (among other factors) the uncertainty in the radiation background; increased knowledge of the expected radiation background will improve the ability to detect low-activity radiological materials. Radiological background due to naturally occurring radiological materials (NORM) can be estimated by reference to previous survey results, use of global 40K, 238U, and 232Th (KUT) values, reference to existing USGS radiation background maps, or by a moving average of the data as it is acquired. Each of these methods has its drawbacks: previous survey results may not include recent changes, the global average provides only a zero-order estimate, the USGS background radiation map resolutions are coarse and are accurate only to 1 km – 25 km sampling intervals depending on locale, and a moving average may essentially low pass filter the data to obscure small changes in radiation counts. Imaging spectroscopy from airborne or spaceborne platforms can offer higher resolution identification of materials and background, as well as provide imaging context information. AVIRIS hyperspectral image data is analyzed using commercial exploitation software to determine the usefulness of imaging spectroscopy to identify qualitative radiological background emissions when compared to airborne radiological survey data.

Bernacki, Bruce E.; Schweppe, John E.; Stave, Sean C.; Jordan, David V.; Kulisek, Jonathan A.; Stewart, Trevor N.; Seifert, Carolyn E.

2014-06-13T23:59:59.000Z

315

The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales  

E-Print Network (OSTI)

spiderweb is then etched in a CF4 RIE gas etch. In the past,small fraction of O 2 to the CF4 etch increases the rate of

Shirokoff, Erik D.

2011-01-01T23:59:59.000Z

316

The South Pole Telescope bolometer array and the measurement of secondary Cosmic Microwave Background anisotropy at small angular scales  

E-Print Network (OSTI)

e-prints, 1007.0290 The Dark Energy Survey Collaboration.distant future, the Dark Energy Survey is expected to beginand near IR. (The Dark Energy Survey Collaboration, 2005) In

Shirokoff, Erik D.

2011-01-01T23:59:59.000Z

317

Tailoring The Microwave Permittivity And Permeability Of Composite Materials  

E-Print Network (OSTI)

1 Tailoring The Microwave Permittivity And Permeability Of Composite Materials Kenneth M. Bober/Lowell, Lowell, MA 01854 ABSTRACT The microwave permittivity( r ) and permeability( r ) of composite materials. Polynomials are also used for the ferrite composites because it was determined that the MG theory was unable

Massachusetts at Lowell, University of

318

Noise properties of mutually sustained microwave-optoelectronic oscillator pair  

E-Print Network (OSTI)

Noise properties of mutually sustained microwave-optoelectronic oscillator pair E. Shumakher and G microwave-optoelectronic oscillator pair are described. The two oscillators have different spectral purities and exhibits low phase noise and highly suppressed spurious modes. Optoelectronic oscillators are employed

Eisenstein, Gadi

319

Tunable negative-tap photonic microwave filter based on a  

E-Print Network (OSTI)

Tunable negative-tap photonic microwave filter based on a cladding-mode coupler and an optically injected laser of large detuning Sze-Chun Chan,* Qing Liu, Zhu Wang, and Kin Seng Chiang Department: A tunable negative-tap photonic microwave filter using a cladding-mode coupler together with optical

Chan, Sze-Chun

320

MICROWAVE-BASED NDE OF FRP-JACKETED CONCRETE STRUCTURES  

E-Print Network (OSTI)

MICROWAVE-BASED NDE OF FRP-JACKETED CONCRETE STRUCTURES Yoo Jin Kim, Franco De Flaviis University are presented in this paper. KEY WORDS: Microwave, Non-Destructive Evaluation (NDE), FRP Jacket, Imaging Technol not be visually observed. Various nondestructive evaluation (NDE) techniques have been studied to detect cracks

De Flaviis, Franco

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network (OSTI)

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering 2012 Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper

Jerby, Eli

322

Thermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby  

E-Print Network (OSTI)

, there is a considerable motivation to develop practical means to ignite pure thermites. Laser beams were found effectiveThermite powder ignition by localized microwaves Yehuda Meir, Eli Jerby Faculty of Engineering Keywords: Thermite Microwave heating Hotspots Thermal runaway Ignition a b s t r a c t This paper presents

Jerby, Eli

323

Broadband microwave burst produced by electron beams  

E-Print Network (OSTI)

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\\tau_l \\approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.

A. T. Altyntsev; G. D. Fleishman; G. -L. Huang; V. F. Melnikov

2007-12-16T23:59:59.000Z

324

Microwave photonics with Josephson junction arrays  

E-Print Network (OSTI)

We introduce an architecture for a photonic crystal in the microwave regime based on superconducting transmission lines interrupted by Josephson junctions. A study of the scattering properties of a single junction in the line shows that the junction behaves as a perfect mirror when the photon frequency matches the Josephson plasma frequency. We generalize our calculations to periodic arrangements of junctions, demonstrating that they can be used for tunable band engineering, forming what we call a quantum circuit crystal. As a relevant application, we discuss the creation of stationary entanglement between two superconducting qubits interacting through a disordered media.

Zueco, David; Solano, Enrique; García-Ripoll, Juan José

2011-01-01T23:59:59.000Z

325

Microwave Plasma Monitoring System For Real-Time Elemental Analysis  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Plasma Monitoring System For Real-Time Elemental Analysis Microwave Plasma Monitoring System For Real-Time Elemental Analysis Microwave Plasma Monitoring System For Real-Time Elemental Analysis The invention apparatus can also be used to monitor for the presence of halogens, sulfur and silicon. Available for thumbnail of Feynman Center (505) 665-9090 Email Microwave Plasma Monitoring System For Real-Time Elemental Analysis There has been invented a process for analyzing ambient air in a microwave induced plasma without use of an additional carrier gas. There has also been invented an apparatus for analyzing ambient air, other sample gas, or nebulized and desolvated liquids wherein a novel arrangement of plasma gas and sample gas conduits is used to enhance dependability of the plasma. This apparatus embodiment of the invention has a concentric arrangement of

326

Mobile system for microwave removal of concrete surfaces  

DOE Patents (OSTI)

A method and apparatus for the microwave removal of contaminated concrete surfaces. The apparatus comprises a housing adapted to pass over a support surface. The housing includes a waveguide for directing microwave energy to the surface at an angle maximizing absorption of microwave energy by the surface. The apparatus is further provided with a source of microwave energy operably associated with the waveguide, wherein the microwave energy has a frequency of between about 10.6 GHz and about 24 GHz and acts to remove the uppermost layer from the surface. The apparatus further includes a debris containment assembly comprising a vacuum assembly operably associated with the housing. The vacuum assembly is adapted to remove debris from the area adjacent the surface.

White, Terry L. (Oak Ridge, TN); Bigelow, Timothy S. (Knoxville, TN); Schaich, Charles R. (Lenoir City, TN); Foster, Jr., Don (Knoxville, TN)

1997-01-01T23:59:59.000Z

327

Container for heat treating materials in microwave ovens  

DOE Patents (OSTI)

The efficiency of a microwave oven of a conventional two-source configuration and energy level is increased by providing the oven with a container for housing a refractory material to be treated. The container is formed of top and bottom walls transparent to microwaves while the sidewalls, in a circular configuration, are formed of a nonmetallic material opaque to microwave radiation reflecting the radiation penetrating the top and bottom walls radially inwardly into the center of the container wherein a casket of heat-insulating material is provided for housing the material to be heat treated. The reflection of the microwave radiation from the sidewalls increases the concentration of the microwaves upon the material being heat treated while the casket retains the heat to permit the heating of the material to a substantially higher temperature than achieveable in the oven without the container.

Holcombe, Cressie E. (Farragut, TN); Dykes, Norman L. (Oak Ridge, TN); Kimrey, Jr., Harold D. (Knoxville, TN); Mills, James E. (Knoxville, TN)

1989-01-01T23:59:59.000Z

328

DOE Hydrogen and Fuel Cells Program: Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Mission and Goals Mission and Goals Organization Chart and Contacts Background U.S. DRIVE Partnership Budget Timeline Program Activities Advisory Panels External Coordination U.S. Department of Energy Search help Home > About > Background Printable Version Background In the early 1970s, concern over our growing dependence on imported petroleum, coupled with concerns about our deteriorating air quality due to emissions from combustion of fossil fuels, spurred the Federal government to act. The timeline below provides policy and programmatic highlights for federally supported hydrogen and fuel cell R&D over the last three decades. Federal Support for Hydrogen and Fuel Cell R&D Some of the following documents are available as Adobe Acrobat PDFs. Download Adobe Reader.

329

National Climate Assessment: Background and Process  

NLE Websites -- All DOE Office Websites (Extended Search)

Background and Process Print E-mail Background and Process Print E-mail Please view the links below to find out more about the background and process of the National Climate Assessment: National Climate Assessment Development & Advisory Committee Charter ( PDF) National Climate Assessment Proposed 2013 Report Outline [updated on 12/08/2011] (PDF) Strategy On May 20th, 2011 the National Climate Assessment released the following two strategy documents: National Climate Assessment Strategy Summary National Climate Assessment Engagement Strategy Federal Register Notices November 18, 2013 National Climate Assessment and Development Advisory Committee (NCADAC) Notice of Open Meeting pdf | html A Notice by the National Oceanic and Atmospheric Administration on 10/29/2013 This notice sets forth the schedule of a forthcoming meeting of the DoC NOAA National Climate Assessment and Development Advisory Committee (NCADAC).

330

Monitored Retrievable Storage Background | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Monitored Retrievable Storage Background Monitored Retrievable Storage Background Monitored Retrievable Storage Background `The U.S. Government is seeking a site for a monitored retrievable storage facility (MRS). Employing proven technologies used in this country and abroad, the MRS will be an Integral part of the Federal system for safe and permanent disposal of the nation's high-level radioactive wastes. The MRS will accept shipments of spent fuel from commercial nuclear power plants, temporarily store the spent fuel above ground, and stage shipments of it to a geologic repository for permanent disposal. The law authorizing the MRS provides an opportunity for a State or an Indian Tribe to volunteer to host the MRS. The law establishes the Office of the Nuclear Waste Negotiator, who Is 10 seek a State or an Indian Tribe

331

THE NEAR-INFRARED BACKGROUND INTENSITY AND ANISOTROPIES DURING THE EPOCH OF REIONIZATION  

SciTech Connect

A fraction of the extragalactic near-infrared (near-IR) background light involves redshifted photons from the ultraviolet (UV) emission from galaxies present during reionization at redshifts above 6. The absolute intensity and the anisotropies of the near-IR background provide an observational probe of the first-light galaxies and their spatial distribution. We estimate the extragalactic background light intensity during reionization by accounting for the stellar and nebular emission from first-light galaxies. We require the UV photon density from these galaxies to generate a reionization history that is consistent with the optical depth to electron scattering from cosmic microwave background measurements. We also require the bright-end luminosity function (LF) of galaxies in our models to reproduce the measured Lyman-dropout LFs at redshifts of 6-8. The absolute intensity is about 0.1-0.4 nW m{sup -2} sr{sup -1} at the peak of its spectrum at {approx}1.1 {mu}m. We also discuss the anisotropy power spectrum of the near-IR background using a halo model to describe the galaxy distribution. We compare our predictions for the anisotropy power spectrum to existing measurements from deep near-IR imaging data from Spitzer/IRAC, Hubble/NICMOS, and AKARI. The predicted rms fluctuations at tens of arcminute angular scales are roughly an order of magnitude smaller than the existing measurements. While strong arguments have been made that the measured fluctuations do not have an origin involving faint low-redshift galaxies, we find that measurements in the literature are also incompatible with galaxies present during the era of reionization. The measured near-IR background anisotropies remain unexplained with an unknown origin.

Cooray, Asantha; Gong Yan; Smidt, Joseph [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Santos, Mario G. [CENTRA, Instituto Superior Tecnico, Technical University of Lisbon, Lisboa 1049-001 (Portugal)

2012-09-01T23:59:59.000Z

332

Analysis and control of the thermal runaway of ceramic slab under microwave heating  

E-Print Network (OSTI)

Analysis and control of the thermal runaway of ceramic slab under microwave heating Changjun Liu of the dielectrics during microwave heating, in which there is a big jump of the steady-state temperature while the applied microwave power varies slightly. It hinders engineers in the applications of microwave heating

Sheen, Dongwoo

333

Ultrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Riad Nechache,  

E-Print Network (OSTI)

hydrothermal processes while requiring significantly less time and energy. In addition, we show that microwaveUltrafast Microwave Hydrothermal Synthesis of BiFeO3 Nanoplates Shun Li, Riad Nechache,§ Ivan and very rapid (1­2 min) microwave-assisted hydrothermal approach. We show that the microwave treatment

334

Energy Efficiency Standards for Microwave Ovens Saves Consumers Energy and Updates the Social Cost of Carbon  

Office of Energy Efficiency and Renewable Energy (EERE)

EERE's new microwave standards will reduce carbon pollution and save consumers money on their energy bills.

335

NEWS & VIEWS nature physics | VOL 4 | FEBRUARY 2008 | www.nature.com/naturephysics 89  

E-Print Network (OSTI)

successful consensus model -- a flat accelerating Universe comprising dark energy, cold dark matter was only beginning to emerge and dark energy had not even been thought of. However, some had a sense different: the discovery of anisotropy in the cosmic microwave background (CMB) was still a decade away

Loss, Daniel

336

Portable microwave instrument for non-destructive evaluation of structural characteristics  

DOE Patents (OSTI)

A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.

Bible, Don W. (Clinton, TN); Crutcher, Richard I. (Knoxville, TN); Sohns, Carl W. (Oak Ridge, TN); Maddox, Stephen R. (Loudon, TN)

1995-01-01T23:59:59.000Z

337

Survey Background and Technical Information on CBECS  

U.S. Energy Information Administration (EIA) Indexed Site

Survey Background and Technical Information Survey Background and Technical Information Survey Background and Technical Information Survey Background The commercial sector encompasses a vast range of building types- service businesses, such as retail and wholesale stores, hotels and motels, restaurants, and hospitals, as well as certain buildings that would not be considered "commercial" in a traditional economic sense, such as public and private schools, correctional institutions, and religious and fraternal organizations. Excluded from the sector are the goods-producing industries: manufacturing, agriculture, mining, forestry and fisheries, and construction. Nearly all energy use in the commercial sector takes place in, or is associated with, the buildings that house these commercial activities. Analysis of the structures, activities, and equipment associated with different types of buildings is the clearest way to evaluate commercial sector energy use. The Commercial Buildings Energy Consumption Survey (CBECS) is a national-level sample survey of commercial buildings and their energy suppliers conducted quadrennially (previously triennially) by the Energy Information Administration (EIA). The 2003 CBECS was the eighth survey in the series begun in 1979. From 1979 to 1986, the survey was known as the Nonresidential Buildings Energy Consumption Survey, or NBECS.

338

Background Simulations for the International Linear Collider  

E-Print Network (OSTI)

on superconducting technology to collide bunches of electrons and positrons. The baseline configuration (about 31 km in a clean experimental environment with low backgrounds. The LHC will likely discover the Higgs boson accelerator directly. DESY FLC, 22603 Hamburg, Germany, adrian.vogel@desy.de 1 #12;Figure 1: Overall view

339

CHAPTER 1 INTRODUCTION 1.1 Background  

E-Print Network (OSTI)

1 CHAPTER 1 INTRODUCTION 1.1 Background This thesis describes a multi-agent based architecture of the research and an outline plan for the rest of this thesis complete the chapter. 1.2 Software Project and monitor progress to check the development is on time and within budget. #12;3 1.3 Software Project

O'Connor, Rory

340

1 Introduction 1.1 Background  

E-Print Network (OSTI)

#12;#12;3 1 Introduction 1.1 Background Research method is a relevant topic to anybody performing. 1.2 Classical Research, Technology and Technology Research The term research is defined in several different ways. According to Merriam-Webster [1], research is "investigation or experimentation aimed

Stølen, Ketil

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Internships at VSTEP BV Background VSTEP  

E-Print Network (OSTI)

, the effect of the current on the ship's manoeuvring characteristics needs to be implemented. 5. A damage (www.quest3d.com) and C++. Background Ship Simulator 2006 One of VSTEP's more recent products is a PC game called Ship Simulator 2006 (www.shipsim.com), in store in many countries since June 2006

Vuik, Kees

342

Carbon Management and Implementation Plan 1. Background  

E-Print Network (OSTI)

the College's energy efficiency and use of resources by integrating sustainability with corporate strategiesCarbon Management and Implementation Plan 1. Background Energy security and the increasing concentration of greenhouse gases which contribute to climate change are one of the biggest challenges facing us

Chittka, Lars

343

Background estimation using a robust Bayesian analysis  

Science Journals Connector (OSTI)

A novel method for the estimation of the background in a powder diffraction pattern has been developed using a robust Bayesian analysis. The underlying probability theory is discussed in terms of going beyond the Gaussian approximation normally associated with counting statistics and least-squares analysis, and various examples are presented that illustrate the general applicability of the approach.

David, W.I.F.

2001-05-22T23:59:59.000Z

344

UCHC Lockout/Tagout Policy Background  

E-Print Network (OSTI)

UCHC Lockout/Tagout Policy (4/09) Background: This safety policy is applicable to all Health Center: Lockout will be utilized for equipment which is designed with a lockout capability. A valve that can be locked out with a chain is considered as having a lockout capability. Only the Office of Research Safety

Kim, Duck O.

345

Cosmic IR Backgrounds Ned Wright (UCLA)  

E-Print Network (OSTI)

Cosmic IR Backgrounds by Ned Wright (UCLA) http://www.astro.ucla.edu/~wright/intro.html See: · http://www.astro.ucla.edu/~wright/cosmolog.htm · http://www.astro.ucla.edu/~wright/DIRBE · http://www.astro.ucla.edu/~wright/CIBR · http

Wright, Edward L. "Ned"

346

Background Material Important Questions about Magnetism  

E-Print Network (OSTI)

Background Material Important Questions about Magnetism: 1) What is Magnetism?Magnetism is a force or repulsion due to charge is called the electric force. But what about magnetism, is there a fundamental property of some matter that makes things magnetic? The answer is: "sort of." Electric current

Mojzsis, Stephen J.

347

Method and apparatus for component separation using microwave energy  

DOE Patents (OSTI)

A method for separating and recovering components includes the steps of providing at least a first component bonded to a second component by a microwave absorbent adhesive bonding material at a bonding area to form an assembly, the bonding material disposed between the components. Microwave energy is directly and selectively applied to the assembly so that substantially only the bonding material absorbs the microwave energy until the bonding material is at a debonding state. A separation force is applied while the bonding material is at the debonding state to permit disengaging and recovering the components. In addition, an apparatus for practicing the method includes holders for the components.

Morrow, Marvin S. (Kingston, TN); Schechter, Donald E. (Ten Mile, TN); Calhoun, Jr., Clyde L. (Knoxville, TN)

2001-04-03T23:59:59.000Z

348

High-Efficiency, Magnetized, Virtual-Cathode Microwave Generator  

Science Journals Connector (OSTI)

Microwave generation by electron beams in virtual-cathode configurations can achieve significant power levels. However, most designs inherently have two competing mechanisms generating microwaves: the oscillating virtual cathode and the reflexing electrons. These mechanisms interfere destructively with each other. This paper reports investigation of a novel idea of using an external axial magnetic field and a thick anode with an appropriate collimating slot to extract the electron beam and to suppress the reflexing electrons. It was found that high-power, narrow-band, monochromatic microwaves could be generated with efficiency of 10% to 20%.

Thomas J. T. Kwan

1986-10-13T23:59:59.000Z

349

Cosmic Glows  

E-Print Network (OSTI)

This is the obligatory Cosmic Microwave Background review. I discuss the current status of CMB anisotropies, together with some points on the related topic of the Far-Infrared Background. We have already learned a number of important things from CMB anisotropies. Models which are in good shape have: approximately flat geometry; cold dark-matter, plus something like a cosmological constant; roughly scale invariant adiabatic fluctuations; and close to Gaussian statistics. The constraints from the CMB are beginning to be comparable to those from other cosmological measurements. With a wealth of new data coming in, it is expected that CMB anisotropies will soon provide the most stringent limits on fundamental cosmological parameters, as well as probing high energy particle physics and the Dark Ages of astrophysics. Nudge, nudge. Wink, wink. Say no more.

Douglas Scott

1999-12-02T23:59:59.000Z

350

Compact microwave ion source for industrial applications  

SciTech Connect

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

2012-02-15T23:59:59.000Z

351

First National Climate Assessment: Background and Process  

NLE Websites -- All DOE Office Websites (Extended Search)

Background and Process Print E-mail Background and Process Print E-mail Workshops of the First National Climate Assessment In February 1997, the U.S. Global Change Research Program and the Office of Science and Technology Policy initiated a series of Regional Climate Change Workshops with the goal of starting the process of examining the vulnerabilities of regions of the United States to climate variability and climate change. What was initially intended to be three or four workshops developed into a series of twenty, covering every state and territory of the United States. The workshops span from May 1997 to September 1998 and represented the first step in conducting a regional assessment. Each workshop was sponsored by one or more government agencies,and was carried out by coordinators from local institutions. For details on each workshop, including its geographic coverage, see:

352

Sideband Mixing in Intense Laser Backgrounds  

E-Print Network (OSTI)

The electron propagator in a laser background has been shown to be made up of a series of sideband poles. In this paper we study this decomposition by analysing the impact of the residual gauge freedom in the Volkov solution on the sidebands. We show that the gauge transformations do not alter the location of the poles. The identification of the propagator from the two-point function is maintained but we show that the sideband structures mix under residual gauge transformations.

Martin Lavelle; David McMullan

2014-07-04T23:59:59.000Z

353

Method for curing polymers using variable-frequency microwave heating  

DOE Patents (OSTI)

A method for curing polymers incorporating a variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity is disclosed. By varying the frequency of the microwave signal, non-uniformities within the cavity are minimized, thereby achieving a more uniform cure throughout the workpiece. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. The furnace cavity may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing. 15 figs.

Lauf, R.J.; Bible, D.W.; Paulauskas, F.L.

1998-02-24T23:59:59.000Z

354

Method for curing polymers using variable-frequency microwave heating  

DOE Patents (OSTI)

A method for curing polymers (11) incorporating a variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34). By varying the frequency of the microwave signal, non-uniformities within the cavity (34) are minimized, thereby achieving a more uniform cure throughout the workpiece (36). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. The furnace cavity (34) may be adapted to be used to cure materials defining a continuous sheet or which require compressive forces during curing.

Lauf, Robert J. (Oak Ridge, TN); Bible, Don W. (Clinton, TN); Paulauskas, Felix L. (Oak Ridge, TN)

1998-01-01T23:59:59.000Z

355

High-precision optical and microwave signal synthesis and distribution  

E-Print Network (OSTI)

In this thesis, techniques for high-precision synthesis of optical and microwave signals and their distribution to remote locations are presented. The first topic is ultrafast optical pulse synthesis by coherent superposition ...

Kim, Jung-Won, 1976-

2007-01-01T23:59:59.000Z

356

Virtual cathode microwave generator having annular anode slit  

DOE Patents (OSTI)

A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit therethrough effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators.

Kwan, Thomas J. T. (Los Alamos, NM); Snell, Charles M. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

357

Exhaust gas treatment by an atmospheric pressure microwave plasma  

Science Journals Connector (OSTI)

A microwave process for treating exhaust gases from internal combustion engines is presented. The exhaust gases are ionised by microwave energy at 2.45 GHz and the resultant plasma jet discharges into ambient air and exhaust gas environment. A gas analyser was used to measure the change in exhaust gas composition due to the influence of the plasma. Large decreases in CO2, CO and hydrocarbon levels, accompanied by an increase in NO levels, were found.

Carlos A. Destefani; Elias Siores

2002-01-01T23:59:59.000Z

358

Optomechanical microwave sensor at the sub-photon level  

E-Print Network (OSTI)

Due to their low energy content microwave signals at the single-photon level are extremely challenging to measure. Guided by recent progress in single-photon optomechanics and hybrid optomechanical systems, we propose a multimode optomechanical transducer that can detect intensities significantly below the single-photon level via adiabatic transfer of the microwave signal to the optical frequency domain where the measurement is then performed. The influence of intrinsic quantum and thermal fluctuations is also discussed.

Keye Zhang; Francesco Bariani; Ying Dong; Weiping Zhang; Pierre Meystre

2014-09-30T23:59:59.000Z

359

Method and device for microwave sintering large ceramic articles  

DOE Patents (OSTI)

A microwave sintering system and method are provided for extremely uniform sintering of large and/or irregular shaped ceramic articles at microwave frequencies of at least 28 GHz in the hundreds of kilowatts power range in an untuned cavity. A 28 GHz, 200 kw gyrotron with variable power output is used as the microwave source connected to an untuned microwave cavity formed of an electrically conductive housing through an overmoded waveguide arrangement which acts in conjunction with a mode promoter within the cavity to achieve unexpected field uniformity. The part to be sintered is placed in the cavity and supported on a removable high temperature table in a central location within the cavity. The part is surrounded by a microwave transparent bulk insulating material to reduce thermal heat loss at the part surfaces and maintain more uniform temperature. The cavity may be operated at a high vacuum to aid in preventing arcing. The system allows controlled increased heating rates of greater than 200.degree. C./min to provide rapid heating of a ceramic part to a selected sintering temperature where it is maintained by regulating the microwave power applied to the part. As a result of rapid heating, the extent of non-isothermal processes such as segregation of impurities to the grain boundaries are minimized and exaggerated grain growth is reduced, thereby strengthening the mechanical properties of the ceramic part being sintered.

Kimrey, Jr., Harold D. (Knoxville, TN)

1990-01-01T23:59:59.000Z

360

Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 1  

SciTech Connect

The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples.

Not Available

1993-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

DOE Vendor Communication Plan I. Background  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Vendor Communication Plan Vendor Communication Plan I. Background On February 2, 2011, the Office of Federal Procurement Policy (OFPP) issued a memorandum entitled "Myth-Busting: Addressing Misconceptions to Improve Communication with Industry during the Acquisition Process." In addition to identifying and refuting common misconceptions about vendor engagement, the memorandum directed agencies to develop high-level vendor communication plans to discuss how each agency will reduce unnecessary barriers, publicize communication opportunities, and prioritize engagement opportunities for high-risk, complex programs or those that fail to attract new vendors during re-competitions.

362

Application of a Microwave-Induced Helium Plasma Detector at Atmospheric Pressure for Gas Chromatographic Capillary Columns  

Science Journals Connector (OSTI)

......microwave-induced plasma emission detector...microwave- induced plasma that operates at atmospheric pressure using helium...to within 1 cm of the plasma discharge. The quartz...Raytheon PGM-10X2 2450 MHz microwave power supply......

Stanley P. Wasik; Frederick P. Schwarz

1980-12-01T23:59:59.000Z

363

../fusion/templates/mapguide/maroon/css/maroon_fusion.css background-image: url(../images/background.gif);  

E-Print Network (OSTI)

../fusion/templates/mapguide/maroon/css/maroon_fusion.css body { background-image: url(../images/background.gif); ../fusion/templates/mapguide/maroon/css/ maroon_fusion.css body { background-color: #3e5c5f; ../fusion/templates/mapguide/maroon/css/ maroon_fusion.css #ToolbarVertical { background: #500000; maroon_fusion.css #Toolbar { background

Ahmad, Sajjad

364

Ignition characteristics of methane/air premixed mixture by microwave-enhanced laser-induced breakdown plasma  

Science Journals Connector (OSTI)

A microwave-enhanced plasma generation technique was combined with laser-induced ignition to improve ignition characteristics. A locally intensified microwave field was formed near the...

Nishiyama, Atsushi; Moon, Ahsa; Ikeda, Yuji; Hayashi, Jun; Akamatsu, Fumiteru

2013-01-01T23:59:59.000Z

365

SEARCH F O R LINEAR POLARIZATION O F THE COSMIC BACKGROUND RADIATION  

NLE Websites -- All DOE Office Websites (Extended Search)

SEARCH F SEARCH F O R LINEAR POLARIZATION O F THE COSMIC BACKGROUND RADIATION P h i l M. Lubin and George F. Smoot Space Sciences L a b o r a t o r y and Lawrence Berkeley L a b o r a t o r y U n i v e r s i t y of C a l i f o r n i a Berkeley, C a l i f o r n i a 94720 Received ABSTRACT W e p r e s e n t p r e l i m i n a r y measurements of t h e l i n e a r p o l a r i z a t i o n of t h e cosmic microwave background ( 3 ° K blackbody) r a d i a t i o n . These ground-based measurements a r e made a t 9 mm wavelength. W e f i n d no e v i d e n c e f o r l i n e a r p o l a r i z a t i o n , and s e t a n upper l i m i t f o r a p o l a r i z e d component of 0.8 m°K with a 95% confidence l e v e l . T h i s i m p l i e s t h a t t h e p r e s e n t rate of e x p a n s i o n of t h e Universe i s i s o t r o p i c t o one p a r t i n 1 0 , assuming no r e - i o n i z a t i o n of t h e p r i m o r d i a l plasma a f t e r recombination. 6 The observed cosmic microwave background r

366

Notices Background The National Wildlife Refuge System  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

89 Federal Register 89 Federal Register / Vol. 74, No. 223 / Friday, November 20, 2009 / Notices Background The National Wildlife Refuge System Administration Act of 1966 (16 U.S.C. 668dd-668ee) (Administration Act), as amended by the National Wildlife Refuge System Improvement Act of 1997, requires us to develop a CCP for each national wildlife refuge. The purpose for developing a CCP is to provide refuge managers with a 15-year plan for achieving refuge purposes and contributing toward the mission of the National Wildlife Refuge System, consistent with sound principles of fish and wildlife management, conservation, legal mandates, and our policies. In addition to outlining broad management direction on conserving wildlife and their habitats, CCPs identify wildlife-

367

Fast neutron background measurements at shallow depths  

SciTech Connect

We report on measurements of the neutron backgrounds for neutrino experiments at shallow depth (such as the proposed San Onofre neutrino oscillation experiment). A detector capable of pulse-shape discrimination measured the flux of fast neutrons at 20 mwe depth in the Stanford Underground Facility to be (1.07 {+-} 0.30) X 10{sup -6} cm{sup -2} s{sup -1}. An experiment, situated in the Tendon Gallery of the San Onofre Unit 2 reactor. studied spallation neutrons from muons traversing Pb and Cu. An underground experiment in the SUF, employing a detector filled with Gd-loaded liquid scintillator, is measuring the neutron production rate and multiplicity for muon spallation in low-A material (hydrocarbon-based liquid scintillator).

Chen, M.; Hertenberger, R.; Novikov, V. [Inst. of Nuclear Research, Moscow (Russian Federation); Dougherty, B.

1993-10-01T23:59:59.000Z

368

Integration of microwave and thermographic NDT methods for corrosion detection  

Science Journals Connector (OSTI)

Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting corroded rebar but at the cost of lengthy scan times. This paper presents an investigation into the potential of utilizing aspects of microwave NDT and thermography to create a hybrid NDT method herein referred to as Active Microwave Thermography (AMT). AMT takes advantage of the electromagnetically lossy nature of corrosion byproducts and uses microwave energy to induce heat in the corrosion. Subsequently the resultant heat profile is captured using an infrared camera. This paper presents initial simulations and measurements that highlight the potential of AMT to detect corroded rebar.

2014-01-01T23:59:59.000Z

369

Reduction of Metal Oxides by Microwave Heating of Multi-walled...  

NLE Websites -- All DOE Office Websites (Extended Search)

Reduction of Metal Oxides by Microwave Heating of Multi-walled Carbon Nanotubes Microwave heating of a metal oxide in the presence of multi-walled carbon nanotubes may result in...

370

Electric Kettle Takes Down Microwave in Final Round of #EnergyFaceoff...  

NLE Websites -- All DOE Office Websites (Extended Search)

Electric Kettle Takes Down Microwave in Final Round of EnergyFaceoff Electric Kettle Takes Down Microwave in Final Round of EnergyFaceoff November 24, 2014 - 12:13pm Addthis The...

371

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002.  

E-Print Network (OSTI)

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002. Copyright SBMO ISSN 1516 one metric is not #12;Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002

Coello, Carlos A. Coello

372

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002.  

E-Print Network (OSTI)

Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002. Copyright SBMO ISSN 1516 investigation is subsequently #12;Journal of Microwaves and Optoelectronics, Vol. 2, N.o 6, December 2002

Coello, Carlos A. Coello

373

Attosecond timing jitter modelocked lasers and ultralow phase noise photonic microwave oscillators  

E-Print Network (OSTI)

Photonic microwave oscillator based on optical frequency comb and ultrastable optical reference cavity represents the state-of-the-art solution to generate X-band microwaves of ultralow phase noise. Such high-quality ...

Li, Duo, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

374

Pyrolysis of Municipal Solid Waste for Syngas Production by Microwave Irradiation  

Science Journals Connector (OSTI)

In the present study, we discuss the application of microwave-irradiated pyrolysis of municipal solid waste (MSW) for total recovery of useful gases and energy. The MSW pyrolysis under microwave irradiation hi...

Vidyadhar V. Gedam; Iyyaswami Regupathi

2012-03-01T23:59:59.000Z

375

E-Print Network 3.0 - argon-helium microwave plasma Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

and Medicine 63 Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator Summary: to efficiently couple the microwave energy into the plasma,...

376

0.6 cu. ft. (17 litre) capacity microwave 700 watts of cooking power  

E-Print Network (OSTI)

. Installation/yearly maintenance not included. Danby ENERGY STAR Mini Fridge (DCR88WDD) Danby Microwave (DMW608W

Lotze, Heike K.

377

In situ RF/microwave remediation of soil experiment overview  

SciTech Connect

Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors are developing an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently, the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The authors objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants.

Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T. [Los Alamos National Lab., NM (United States); Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)

1995-09-01T23:59:59.000Z

378

Purcell effect with microwave drive: Suppression of qubit relaxation rate  

E-Print Network (OSTI)

We analyze the Purcell relaxation rate of a superconducting qubit coupled to a resonator, which is coupled to a transmission line and pumped by an external microwave drive. Considering the typical regime of the qubit measurement, we focus on the case when the qubit frequency is significantly detuned from the resonator frequency. Surprisingly, the Purcell rate decreases when the strength of the microwave drive is increased. This suppression becomes significant in the nonlinear regime. In the presence of the microwave drive, the loss of photons to the transmission line also causes excitation of the qubit; however, the excitation rate is typically much smaller than the relaxation rate. Our analysis also applies to a more general case of a two-level quantum system coupled to a cavity.

Eyob A. Sete; Jay M. Gambetta; Alexander N. Korotkov

2014-01-22T23:59:59.000Z

379

Application of microwave solidification technology to radioactive waste  

SciTech Connect

The EPA has declared vitrification to be the Best Available Demonstrated Technology (BDAT) for High Level Radioactive Waste (40 CFR 268.42). Vitrification has been chosen as the method of choice for treating a number of radioactive residues and wastes in the DOE complex. Vitrification offers advantages of waste volume reduction, the ability to handle changing waste forms, and a stable, nonleachable final waste form. Microwave heating is a superior method for vitrification of radioactive wastes. Advantages of microwave heating include: (1) direct waste heating, eliminates need for electrodes, refractories and other consumables; (2) ``in-can`` processing allows for treatment of the material in its final container, (3) a mechanically simple system where the microwaves are generated away from the treatment area and transmitted to the treatment applicator by a wave guide, thus minimizing worker exposure to radiation; (4) easier equipment maintenance; and (5) a high degree of public acceptance.

Harris, M.; Sprenger, G.; Roushey, B.; Fenner, G.; Nieweg, R.

1995-09-28T23:59:59.000Z

380

Constraining large–scale structure theories with the cosmic background radiation  

Science Journals Connector (OSTI)

...parameters such as the energy densities of baryons, cold and hot dark matter, in the vacuum...that LSS redshift surveys probe. The density...CMB and LSS redshift survey results we will get...parameter h, various mean energy densities {tot...

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Optical control of microwaves with semiconductor n?i?p?i structures  

Science Journals Connector (OSTI)

We control the microwave transmission of a GaAsn?i?p?i structure by illuminating it with a cw argon ion laser. Tests in a broadband microwave modulator wave spectrometer show that an optical intensity of 800 mW/cm2 produces a 50% change in transmission for microwaves between 10 and 50 GHz.

Alan Kost; Linda West; T. C. Hasenberg; Jeffrey O. White; Mehran Matloubian; George C. Valley

1993-01-01T23:59:59.000Z

382

Differential Damage in Bacterial Cells by Microwave Radiation on the Basis of Cell Wall Structure  

Science Journals Connector (OSTI)

...consistent when the microwave radiation was repeated. Changes in the...NaCl was exposed to microwave radiation at 600 W, and its temperature...U200; Hitachi Co., Tokyo, Japan). All the experiments were...cells were treated by microwave radiation, the shape of the cells was...

Im-Sun Woo; In-Koo Rhee; Heui-Dong Park

2000-05-01T23:59:59.000Z

383

Microwave and EUV Observations of an Erupting Filament and Associated Flare and Coronal Mass Ejections  

Science Journals Connector (OSTI)

......feature was 5.51 MHz at 07:48 UT, and...High-Temperature Plasma to the Microwave...microwave emission from plasma below this temperature...case of a stratified atmosphere; then, the integrations...high- temperature plasma to the microwave...operating at 5743 MHz (5.2 cm), observed......

Costas E. Alissandrakis; Alexey A. Kochanov; Spiros Patsourakos; Alexander T. Altyntsev; Sergey V. Lesovoi; Nadya N. Lesovoya

2013-12-05T23:59:59.000Z

384

Microwave-assisted sample preparation of coal and coal fly ash for subsequent metal determination  

SciTech Connect

The aim of this paper is to review microwave-assisted digestion of coal and coal fly ash. A brief description of microwave heating principles is presented. Microwave-assisted digestion appears currently to be the most popular preparation technique, possibly due to the comparatively rapid sample preparation and the reduction of contamination, compared to the conventional hot-plate digestion methods.

Srogi, K. [Inst. of Chemical Processing of Coal, Zabrze (Poland)

2007-01-15T23:59:59.000Z

385

CAD Technique for Microwave Chemistry Reactors with Energy Efficiency Optimized for Different Reactants  

E-Print Network (OSTI)

CAD Technique for Microwave Chemistry Reactors with Energy Efficiency Optimized for Different in experimental development of large- scale and highly-productive reactors. This paper proposes to address this issue by developing microwave chemistry reactors as microwave systems, rather than as black

Yakovlev, Vadim

386

Apparatus with moderating material for microwave heat treatment of manufactured components  

DOE Patents (OSTI)

An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

Ripley, Edward B. (Knoxville, TN)

2011-05-10T23:59:59.000Z

387

Schwarzschild black hole in dark energy background  

E-Print Network (OSTI)

In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

2014-09-27T23:59:59.000Z

388

The Quest for Ultimate Broadband High Power Microwaves  

E-Print Network (OSTI)

Paper describes High Power Microwave research of combining GW peak power to achieve MV/m and GV/m radiated fields in 1 to 500 GHz band. To achieve such fields multiple independently triggered broadband GW sources, supplying power to multiple spatially distributed broadband radiators/antennas are used. Single TW array is used as an ultimate microwave weapon in 1 to 5 GHz range while multiple TW arrays provide GV/m radiating field at plasma frequencies in 300 GHz range leading to fusion power.

Podgorski, Andrew S

2014-01-01T23:59:59.000Z

389

Pressure History Measurement in a Microwave Beaming Thruster  

Science Journals Connector (OSTI)

In a microwave beaming thruster with a 1?dimensional nozzle plasma and shock wave propagates in the nozzle absorbing microwave power. In this study pressure histories in the thruster are measured using pressure gauges. Measured pressure history at the thruster wall shows constant pressure during plasma propagation in the nozzle. The result of measurement of the propagating velocities of shock wave and plasma shows that both propagate in the same velocity. These result shows that thrust producing model of analogy of pulse detonation engine is successful for the 1D thruster.

Yasuhisa Oda; Masato Ushio; Kimiya Komurasaki; Koji Takahashi; Atsushi Kasugai; Keishi Sakamoto

2006-01-01T23:59:59.000Z

390

Ultra high vacuum broad band high power microwave window  

DOE Patents (OSTI)

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

Nguyen-Tuong, Viet (Seaford, VA); Dylla, III, Henry Frederick (Yorktown, VA)

1997-01-01T23:59:59.000Z

391

Ultra high vacuum broad band high power microwave window  

DOE Patents (OSTI)

An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

Nguyen-Tuong, V.; Dylla, H.F. III

1997-11-04T23:59:59.000Z

392

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network (OSTI)

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Parker, Stephen R; Povey, Rhys G; Tobar, Michael E

2014-01-01T23:59:59.000Z

393

Cryogenic resonant microwave cavity searches for hidden sector photons  

E-Print Network (OSTI)

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53 $\\mu$eV we limit the hidden photon kinetic mixing parameter $\\chi cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2014-10-20T23:59:59.000Z

394

Cryogenic resonant microwave cavity searches for hidden sector photons  

Science Journals Connector (OSTI)

The hidden sector photon is a weakly interacting hypothetical particle with sub-eV mass that kinetically mixes with the photon. We describe a microwave frequency light shining through a wall experiment, where a cryogenic resonant microwave cavity is used to try and detect photons that have passed through an impenetrable barrier, a process only possible via mixing with hidden sector photons. For a hidden sector photon mass of 53???eV, we limit the hidden photon kinetic mixing parameter ?cryogenic detector cavity to place new limits on the kinetic mixing parameter for hidden sector photons as a form of cold dark matter.

Stephen R. Parker; John G. Hartnett; Rhys G. Povey; Michael E. Tobar

2013-12-03T23:59:59.000Z

395

Photonic microwave generation with high-power photodiodes  

E-Print Network (OSTI)

We utilize and characterize high-power, high-linearity modified uni-traveling carrier (MUTC) photodiodes for low-phase-noise photonic microwave generation based on optical frequency division. When illuminated with picosecond pulses from a repetition-rate-multiplied gigahertz Ti:sapphire modelocked laser, the photodiodes can achieve 10 GHz signal power of +14 dBm. Using these diodes, a 10 GHz microwave tone is generated with less than 500 attoseconds absolute integrated timing jitter (1 Hz-10 MHz) and a phase noise floor of -177 dBc/Hz. We also characterize the electrical response, amplitude-to-phase conversion, saturation and residual noise of the MUTC photodiodes.

Fortier, Tara M; Hati, Archita; Nelson, Craig; Taylor, Jennifer A; Fu, Yang; Campbell, Joe; Diddams, Scott A

2013-01-01T23:59:59.000Z

396

Building Technologies Office: Home Energy Score Research and Background  

NLE Websites -- All DOE Office Websites (Extended Search)

Research and Background to someone by E-mail Research and Background to someone by E-mail Share Building Technologies Office: Home Energy Score Research and Background on Facebook Tweet about Building Technologies Office: Home Energy Score Research and Background on Twitter Bookmark Building Technologies Office: Home Energy Score Research and Background on Google Bookmark Building Technologies Office: Home Energy Score Research and Background on Delicious Rank Building Technologies Office: Home Energy Score Research and Background on Digg Find More places to share Building Technologies Office: Home Energy Score Research and Background on AddThis.com... About Take Action to Save Energy Partner With DOE Activities Solar Decathlon Building America Home Energy Score Get Involved Partners Research & Background

397

DSM/SPhT-T06/004http://www-spht.cea.fr/articles/T06/004/ The shape of high order correlation functions in CMB anisotropy maps  

E-Print Network (OSTI)

DSM/SPhT-T06/004http://www-spht.cea.fr/articles/T06/004/ The shape of high order correlation functions in CMB anisotropy maps Tristan Brunier and Francis Bernardeau Service de Physique Th´eorique, CEA/DSM

Paris-Sud XI, Université de

398

Non-absorbing high-efficiency counter for itinerant microwave photons  

E-Print Network (OSTI)

Detecting an itinerant microwave photon with high efficiency is an outstanding problem in microwave photonics and its applications. We present a scheme to detect an itinerant microwave photon in a transmission line via the nonlinearity provided by a transmon in a driven microwave resonator. With a single transmon we achieve 84% distinguishability between zero and one microwave photons and 90% distinguishability with two cascaded transmons by performing continuous measurements on the output field of the resonator. We also show how the measurement diminishes coherence in the photon number basis thereby illustrating a fundamental principle of quantum measurement: the higher the measurement efficiency, the faster is the decoherence.

Bixuan Fan; Göran Johansson; Joshua Combes; G. J. Milburn; Thomas M. Stace

2014-03-18T23:59:59.000Z

399

Environmental assessment for the Satellite Power System (SPS) Concept Development and Evaluation Program (CDEP). [Microwave and non-microwave health and ecological assessment  

SciTech Connect

In the satellite power system (SPS), satellites in geosynchronous earth orbit would collect solar energy in space, convert it to microwaves, and transmit the microwaves to receiving antennas (rectennas) on earth. At the rectennas, the microwave energy would be converted to electricity. This SPS environmental assessment considers the microwave and nonmicrowave effects on the terrestrial environment and human health, atmospheric effects, and effects on electromagnetic systems. No environmental problem has been identified that would preclude the continued study of SPS technology. To increase the certainty of the assessment, some research has been initiated and long-term research is being planned.

Valentino, A.R.

1980-08-01T23:59:59.000Z

400

Non-fusion applications of RF and microwave technology  

SciTech Connect

The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.

Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C.; White, T.L.

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Electrically long vertical interconnects for microwave circuits and antennas  

E-Print Network (OSTI)

. . . . . 2 . . . . 3 . . . . 4 . 4 . 4 . 5 . . . . 5 . . . . 6 . . . . 7 A. Transmission Line Interconnects. . B. Electromagnetically Coupled lnterconnects . . . . . C. Conclusions . . . . . . 8 . . . 10 III FIDELITY SIMULATION 12 A. B. C. D... interconnects satisfying specifications set by Raytheon Systems Co. This research was sponsored by Raytheon Systems Co. RF/Microwave Division. A vertical interconnect couples transmission lines, antennas, and components between vertically spaced layers...

Coutant, Matthew Richard

2012-06-07T23:59:59.000Z

402

Multi-modal transmission of microwaves through hole arrays  

E-Print Network (OSTI)

. R. Evans, and J. R. Sambles, "Experimental verification of designer surface plasmons," Science 308Multi-modal transmission of microwaves through hole arrays James D. Edmunds,1,* Euan Hendry,1(5722), 670­672 (2005). 8. S. A. Maier, S. R. Andrews, L. Martín-Moreno, and F. J. García-Vidal, "Terahertz

Exeter, University of

403

ECRH microwave beam broadening in the edge turbulent plasma  

SciTech Connect

The influence of turbulent plasma density fluctuations on angular and spatial beam width is treated analytically in the framework of WKB based eikonal method. Reasonable agreement of analytical and numerical treatment results is demonstrated within the domain of quasi-optical approximation validity. Significant broadening of microwave beams is predicted for future ECRH experiments at ITER.

Sysoeva, E. V.; Gusakov, E. Z.; Popov, A. Yu. [Ioffe Institute, St. Petersburg, Russia and RL PAT SPbSPU, St. Petersburg (Russian Federation); Silva, F. da [Institute of Plasmas and Nuclear Fusion, IST, Lisbon (Portugal); Heuraux, S. [IJL UMR-7198 CNRS-Université de Lorraine, BP70239, 54506 Vandoeuvre Cedex (France)

2014-02-12T23:59:59.000Z

404

Experimental Investigation of Microwave Vulnerabilities in CMOS Inverters  

E-Print Network (OSTI)

Experimental Investigation of Microwave Vulnerabilities in CMOS Inverters Agis A. Iliadis effects on single CMOS inverters, the fundamental building block of logic ICs, consisting of an NMOS and a PMOS transistor. The inverters were designed in our group and fabricated in the AMI-1.5µm MOSIS line

Anlage, Steven

405

International Microwave Power Institute 127 ANALYSIS OF OPERATIONAL REGIMES  

E-Print Network (OSTI)

for microwave heating. KEY WORDS: Electric field, dissipated power, micro- wave power, model, permittivity heating systems oper ating at 915 MHz is a standard feature protecting the magnetron from reflections LOAD E. Eves and V. Yakovlev Reflections, electric field and dissipated power of a 915 MHz water load

Yakovlev, Vadim

406

Microwave Radiometer – 3 Channel (MWR3C) Handbook  

SciTech Connect

The microwave radiometer 3-channel (MWR3C) provides time-series measurements of brightness temperatures from three channels centered at 23.834, 30, and 89 GHz. These three channels are sensitive to the presence of liquid water and precipitable water vapor.

Cadeddu, MP

2012-05-04T23:59:59.000Z

407

Flexible Graphene Field-Effect Transistors for Microwave Electronics  

E-Print Network (OSTI)

Flexible Graphene Field-Effect Transistors for Microwave Electronics Inanc Meric , Nicholas Petrone-frequency characteristics of graphene field-effect transistors (GFETs) has received significant interest due the very high carrier velocities in graphene. In addition to excellent electronic performance, graphene possesses

Shepard, Kenneth

408

Controlling Nanoparticle Aggregation in Colloidal Microwave Absorbers via Interface Chemistry  

E-Print Network (OSTI)

Controlling Nanoparticle Aggregation in Colloidal Microwave Absorbers via Interface Chemistry Brian ABSTRACT Interface chemistry can be implemented to modulate the aggregation and dispersion of nanoparticles of superparamagnetic magnetite nanoparticles in organic and aqueous solutions. With decrease in solution pH, individual

Stowell, Michael

409

Metal slits and liquid crystals at microwave frequencies  

Science Journals Connector (OSTI)

...the possible use of dual frequency materials to allow drive-on as well as drive-off. Unfortunately such dual-frequency materials have reduced...T Nomoto2002Microwave variable delay line using dual-frequency switching-mode liquid...

2006-01-01T23:59:59.000Z

410

System to continuously produce carbon fiber via microwave assisted plasma processing  

DOE Patents (OSTI)

A method for continuously processing carbon fiber including establishing a microwave plasma in a selected atmosphere contained in an elongated chamber having a microwave power gradient along its length defined by a lower microwave power at one end and a higher microwave power at the opposite end of the elongated chamber. The elongated chamber having an opening in each of the ends of the chamber that are adapted to allow the passage of the fiber tow while limiting incidental gas flow into or out of said chamber. A continuous fiber tow is introduced into the end of the chamber having the lower microwave power. The fiber tow is withdrawn from the opposite end of the chamber having the higher microwave power. The fiber to is subjected to progressively higher microwave energy as the fiber is being traversed through the elongated chamber.

White, Terry L; Paulauskas, Felix L; Bigelow, Timothy S

2014-03-25T23:59:59.000Z

411

Evidence-Based Background Material Underlying Guidance for Federal...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Material Underlying Guidance for Federal Agencies in Implementing Strategic Sustainability Performance Plans Evidence-Based Background Material Underlying Guidance for...

412

Muon-induced backgrounds in the CUORICINO experiment  

E-Print Network (OSTI)

background in the neutrinoless double beta decay region ofis searching for neutrinoless double beta decay (0???), a

Andreotti, E.

2010-01-01T23:59:59.000Z

413

Surface-wave-enabled darkfield aperture for background suppression during  

E-Print Network (OSTI)

can be directly incorporated onto optical sensors to accom- plish predetection background suppression if the sensor is fully capable of measuring the same weak signal in the absence of background (1, 2- trivial to employ. A sensor that can intrinsically cancel a strong background prior to signal detection

Yang, Changhuei

414

PoGOLite: Neutron Background Studies for High Latitudes  

E-Print Network (OSTI)

PoGOLite: Neutron Background Studies for High Latitudes Maria Fernanda Muñoz Salinas SH2006. The measurements showed a neutron background ten times higher than expected. Because of this, new simulations of the PoGOLite flight which will take place in the summer of 2012. The neutron background was simulated

Haviland, David

415

Matrix Model in a Class of Time Dependent Supersymmetric Backgrounds  

E-Print Network (OSTI)

We discuss the matrix model in a class of 11D time dependent supersymmetric backgrounds as obtained in hep-th/0508191 . We construct the matrix model action through the matrix regularization of the membrane action in the background. We show that the action is exact to all order of fermionic coordinates. Furthermore We discuss the fuzzy sphere solutions in this background.

Hong-Zhi Chen; Bin Chen

2006-03-19T23:59:59.000Z

416

Role of Background in the CERCLA Cleanup Program  

NLE Websites -- All DOE Office Websites (Extended Search)

Background in the CERCLA Cleanup Program Background in the CERCLA Cleanup Program U.S. Environmental Protection Agency Office of Solid Waste and Emergency Response Office of Emergency and Remedial Response April 26, 2002 OSWER 9285.6-07P OSWER 9285.6-07P page 2 of 13 Table of Contents Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 3 of 13 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 13 Definitions of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5 of 13 Consideration of Background in Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6 of 13 Consideration of Background in Risk Management . . . . . . . . . . . . . . . . . . . . . . . . . Page 7 of 13 Consideration of Background in Risk Communication . . . . . . . . . . . . . . . . . . . . . . . Page 8 of 13 Hypothetical Case Examples .

417

Electroweak Corrections to Photon Scattering, Polarization and Lensing in a Gravitational Background and the Near Horizon Limit  

E-Print Network (OSTI)

We investigate the semiclassical approach to the lensing of photons in a spherically symmetric gravitational background, starting from Born level and include in our analysis the radiative corrections obtained from the electroweak theory for the graviton/photon/photon vertex. In this approach, the cross section is related to the angular variation of the impact parameter ($b$), which is then solved for $b$ as a function of the angle of deflection, and measured in horizon units ($b_h\\equiv b/(2 G M)$). Exact numerical solutions for the angular deflection are presented. The numerical analysis shows that perturbation theory in a weak background agrees with the classical Einstein formula for the deflection already at distances of the order of $20$ horizon units ($\\sim 20\\, b_h$) and it is optimal in the description both of very strong and weak lensings. We show that the electroweak corrections to the cross section are sizeable, becoming very significant for high energy gamma rays. Our analysis covers in energy most of the photon spectrum, from the cosmic microwave background up to very high energy gamma rays, and scatterings with any value of the photon impact parameter. We also study the helicity-flip photon amplitude, which is of $O(\\alpha^2)$ in the weak coupling $\\alpha$, and its massless fermion limit, which involves the exchange of a conformal anomaly pole. The corresponding cross section is proportional to the Born level result and brings to a simple renormalization of Einsten's formula.

Claudio Coriano; Luigi Delle Rose; Matteo Maria Maglio; Mirko Serino

2014-11-11T23:59:59.000Z

418

Effect of microwave radiation on Jayadhar cotton fibers: WAXS studies  

SciTech Connect

Thermal effect in the form of micro wave energy on Jayadhar cotton fiber has been investigated. Microstructural parameters have been estimated using wide angle x-ray scattering (WAXS) data and line profile analysis program developed by us. Physical properties like tensile strength are correlated with X-ray results. We observe that the microwave radiation do affect significantly many parameters and we have suggested a multivariate analysis of these parameters to arrive at a significant result.

Niranjana, A. R., E-mail: arnphysics@gmail.com; Mahesh, S. S., E-mail: arnphysics@gmail.com; Divakara, S., E-mail: arnphysics@gmail.com; Somashekar, R., E-mail: arnphysics@gmail.com [Department of Studies in Physics, University of Mysore, Mysore-570006 (India)

2014-04-24T23:59:59.000Z

419

Microwave-Assisted Synthesis of Fluorescent Carbon Nanoparticles  

E-Print Network (OSTI)

MICROWAVE-ASSITED SYNTHESIS OF FLUORESCENT CARBON NANOPARTICLES A Thesis by BONNIE CHEN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree...-(hydroxymethyl) furfural (5- HMF) derivatives, which are major products of glucose decomposition. iv ACKNOWLEDGEMENTS This thesis was completed in my fourth year at Texas A&M University as a master's student, and analyzes, discusses and displays...

Chen, Bonnie

2014-08-19T23:59:59.000Z

420

Novel Birefringent Frequency Discriminator for Microwave Photonic Links  

E-Print Network (OSTI)

NOVEL BIREFRINGENT FREQUENCY DISCRIMINATOR FOR MICROWAVE PHOTONIC LINKS A Dissertation by JAE HYUN KIM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...-Division Multiplexing OPD Optical Path Length Different OVA Optical Vector Network Analyzer PBS Polarization Beam Splitter PM Phase Modulation PD Photodiode PDL Polarization Dependent Loss PLC Planar Lightwave Circuit QWP Quarter Wave Plate RAMZI Ring...

Kim, Jae Hyun

2013-04-22T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Microwave studies of weak localization and antilocalization in epitaxial graphene  

SciTech Connect

A microwave detection method was applied to study weak localization and antilocalization in epitaxial graphene sheets grown on both polarities of SiC substrates. Both coherence and scattering length values were obtained. The scattering lengths were found to be smaller for graphene grown on C-face of SiC. The decoherence rate was found to depend linearly on temperature, showing the electron-electron scattering mechanism.

Drabi?ska, Aneta; Kami?ska, Maria [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Wo?o?, Agnieszka [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Strupinski, Wlodek [Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland)

2013-12-04T23:59:59.000Z

422

Fabrication and characterization of aluminum airbridges for superconducting microwave circuits  

SciTech Connect

Superconducting microwave circuits based on coplanar waveguides (CPW) are susceptible to parasitic slotline modes which can lead to loss and decoherence. We motivate the use of superconducting airbridges as a reliable method for preventing the propagation of these modes. We describe the fabrication of these airbridges on superconducting resonators, which we use to measure the loss due to placing airbridges over CPW lines. We find that the additional loss at single photon levels is small, and decreases at higher drive powers.

Chen, Zijun; Kelly, J.; Barends, R.; Bochmann, J.; Chen, Yu; Chiaro, B.; Dunsworth, A.; Jeffrey, E.; Mutus, J. Y.; O'Malley, P. J. J.; Neill, C.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T. C. [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); Megrant, A. [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); Department of Materials, University of California, Santa Barbara, California 93106 (United States); Cleland, A. N.; Martinis, John M., E-mail: martinis@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); California NanoSystems Institute, University of California, Santa Barbara, California 93106-9530 (United States)

2014-02-03T23:59:59.000Z

423

Microwaves and Chemistry: The Catalysis of an Exciting Marriage  

E-Print Network (OSTI)

of microwave catalysts employed. We should emphasize that water as a reactant is in the adsorbed state Oil the catalyst's sUlfaces. Indeed, both the hydrocarbon and water are adsorbed on the surfaces and the primary reaction of the oxidation takes place.... For this reason, it is important to realize that the methods of introducing and maintaining the concentrations of adsorbed water on the surfaces effectively control the efficiency and the selectivity of the oxidation products. This is equally true...

Wan, J.

424

Measuring plasma turbulence using low coherence microwave radiation  

SciTech Connect

Low coherence backscattering (LCBS) is a proposed diagnostic technique for measuring plasma turbulence and fluctuations. LCBS is an adaptation of optical coherence tomography, a biomedical imaging technique. Calculations and simulations show LCBS measurements can achieve centimeter-scale spatial resolution using low coherence microwave radiation. LCBS measurements exhibit several advantages over standard plasma turbulence measurement techniques including immunity to spurious reflections and measurement access in hollow density profiles. Also, LCBS is scalable for 1-D profile measurements and 2-D turbulence imaging.

Smith, D. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2012-02-20T23:59:59.000Z

425

Microsoft PowerPoint - Powerpoint_Background.ppt [Compatibility Mode]  

NLE Websites -- All DOE Office Websites (Extended Search)

g g Radiation Radiation Radiation is everywhere Cosmic Inhaled Radon Inhaled Radon Bodies Plants Bodies Radioactive Elements We live in a sea of radiation... Rocks BACKGROUND RADIATION BACKGROUND RADIATION The average background radiation per person is 370 millirems per person is 370 millirems (mrem) per year. This varies widely depending on where someone lives and their someone lives, and their occupation, health and lifestyle. Background Radiation g Most background radiation is g natural. It is part of nat re It is part of nature. It has always been here. y People have always lived with it. Radiation comes from space- sun and cosmic rays Because this type of radiation is somewhat shielded by the atmosphere, y p the dose is higher at higher altitudes Background Radiation Exposure at Different Elevations

426

Overcoming High Energy Backgrounds at Pulsed Spallation Sources  

E-Print Network (OSTI)

Instrument backgrounds at neutron scattering facilities directly affect the quality and the efficiency of the scientific measurements that users perform. Part of the background at pulsed spallation neutron sources is caused by, and time-correlated with, the emission of high energy particles when the proton beam strikes the spallation target. This prompt pulse ultimately produces a signal, which can be highly problematic for a subset of instruments and measurements due to the time-correlated properties, and different to that from reactor sources. Measurements of this background have been made at both SNS (ORNL, Oak Ridge, TN, USA) and SINQ (PSI, Villigen, Switzerland). The background levels were generally found to be low compared to natural background. However, very low intensities of high-energy particles have been found to be detrimental to instrument performance in some conditions. Given that instrument performance is typically characterised by S/N, improvements in backgrounds can both improve instrument pe...

Cherkashyna, Nataliia; DiJulio, Douglas D; Khaplanov, Anton; Pfeiffer, Dorothea; Scherzinger, Julius; Cooper-Jensen, Carsten P; Fissum, Kevin G; Ansell, Stuart; Iverson, Erik B; Ehlers, Georg; Gallmeier, Franz X; Panzner, Tobias; Rantsiou, Emmanouela; Kanaki, Kalliopi; Filges, Uwe; Kittelmann, Thomas; Extegarai, Maddi; Santoro, Valentina; Kirstein, Oliver; Bentley, Phillip M

2015-01-01T23:59:59.000Z

427

Interfacing microwave qubits and optical photons via spin ensembles  

E-Print Network (OSTI)

A protocol is discussed which allows one to realize a transducer for single photons between the optical and the microwave frequency range. The transducer is a spin ensemble, where the individual emitters possess both an optical and a magnetic-dipole transition. Reversible frequency conversion is realized by combining optical photon storage, by means of EIT, with the controlled switching of the coupling between the magnetic-dipole transition and a superconducting qubit, which is realized by means of a microwave cavity. The efficiency is quantified by the global fidelity for transferring coherently a qubit excitation between a single optical photon and the superconducting qubit. We test various strategies and show that the total efficiency is essentially limited by the optical quantum memory: It can exceed 80% for ensembles of NV centers and approaches 99% for cold atomic ensembles, assuming state-of-the-art experimental parameters. This protocol allows one to bridge the gap between the optical and the microwave regime so to efficiently combine superconducting and optical components in quantum networks.

Susanne Blum; Christopher O'Brien; Nikolai Lauk; Pavel Bushev; Michael Fleischhauer; Giovanna Morigi

2015-01-23T23:59:59.000Z

428

Propagation in 3D of microwaves through density perturbations  

E-Print Network (OSTI)

Simulations using 3D and 2D full-wave codes have shown that edge filaments in tokamak plasmas can significantly affect the propagation of microwaves across a broad frequency spectrum, resulting in scattering angles of up to 46 degrees. Parameter scans were carried out for density perturbations comparable in width and amplitude to MAST filaments and the effect on the measured emission was calculated. 3D effects were discovered in the case of an obliquely incident beam. In general, the problem of EM propagation past wavelength-sized 3D inhomogeneities is not well understood, yet is of importance for both heating and diagnostic applications in the electron cyclotron frequency range for tokamaks, as well as atmospheric physics. To improve this understanding, a new cold-plasma code, EMIT-3D, was written to extend full-wave microwave simulations in magnetized plasmas to 3D, and make comparisons to the existing 2D code IPF-FDMC. This work supports MAST experiments using the SAMI diagnostic to image microwave emissio...

Williams, T R N; O'Brien, M R; Vann, R G L

2013-01-01T23:59:59.000Z

429

The Killing superalgebra of ten-dimensional supergravity backgrounds  

E-Print Network (OSTI)

We construct the Killing superalgebra of supersymmetric backgrounds of ten-dimensional heterotic and type II supergravities and prove that it is a Lie superalgebra. We also show that if the fraction of supersymmetry preserved by the background is greater than 1/2, in the heterotic case, or greater than 3/4 in the type II case, then the background is locally homogeneous.

José Figueroa-O'Farrill; Emily Hackett-Jones; George Moutsopoulos

2007-03-21T23:59:59.000Z

430

A microwave tomography system using a tunable mirror for beam steering  

SciTech Connect

Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

Tayebi, A. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physic (United States); Tang, J. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Paladhi, P. Roy; Udpa, L.; Udpa, S. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2014-02-18T23:59:59.000Z

431

Smoothing of the cosmic background radiation by multiple gravitational scattering  

Science Journals Connector (OSTI)

We investigated the smoothing of the cosmic background radiation (CBR) ... rays increases exponentially through multiple scatterings. This exponential growth occurs if the distance is smaller...

Junichiro Making

1994-01-01T23:59:59.000Z

432

Backgrounds and Projected Limits from Dark Matter Direct Detection Experiments  

E-Print Network (OSTI)

A simple formula is introduced which indicates the amount by which projections of dark matter direct detection experiments are expected to be degraded due to backgrounds.

Scott Dodelson

2008-12-08T23:59:59.000Z

433

ESnet supports Sandia and APNIC IPv6 Background Radiation research  

NLE Websites -- All DOE Office Websites (Extended Search)

supports Sandia and APNIC IPv6 Background Radiation research Engineering Services The Network OSCARS Fasterdata IPv6 Network IPv6 Implementation Checklist ESnet IPv6 Mirror Servers...

434

Muon-induced backgrounds in the CUORICINO experiment  

E-Print Network (OSTI)

Muon-induced backgrounds in the CUORICINO experiment E.the contribution of cosmic ray muons to the CUORICINOKey words: CUORICINO, muons, cosmic rays, double beta decay,

Andreotti, E.

2010-01-01T23:59:59.000Z

435

Assessment of microwave power flow for reflectometry measurements in tokamak plasmas  

E-Print Network (OSTI)

measurements in tokamak plasmas P. -A. Gourdain a , W. A.are widely employed in tokamak fusion plasmas, and are alsoresearch devices, such as tokamaks, microwave reflectometry

Gourdain, P-A; Peebles, W. A.

2008-01-01T23:59:59.000Z

436

Microwave Regenerated DPF for Auxiliary Power Units and Diesel Hybrid Vehicles  

Energy.gov (U.S. Department of Energy (DOE))

Microwave regeneration of the DPF can be done without diesel fuel or a catalyst in less than 5 minutes with the engine off.

437

Electric Kettle Takes Down Microwave in Final Round of #EnergyFaceoff  

Energy.gov (U.S. Department of Energy (DOE))

The final round of #EnergyFaceoff goes to the electric kettle! See how much it can save compared to a microwave when heating water.

438

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources  

DOE Patents (OSTI)

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Alton, G.D.

1998-11-24T23:59:59.000Z

439

E-Print Network 3.0 - aces microwave link Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Microw. Theory Tech., vol... 1 Abstract-- A novel approach to generating a frequency- tunable microwave or sub-terahertz wave... a dispersive fiber. By applying these optical...

440

Microwave vs. Electric Kettle: Which Appliance Is in Hot Water in #EnergyFaceoff Round 4?  

Energy.gov (U.S. Department of Energy (DOE))

In the final #EnergyFaceoff round, the electric kettle takes on the microwave for the honor of heating your water.

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Microwave cavity searches for dark-matter axions  

Science Journals Connector (OSTI)

Recent determinations of cosmological parameters point to a flat Universe, whose total energy density is composed of about two-thirds vacuum energy and one-third matter. Ordinary baryonic matter is relegated to a small fraction of the latter, within which the luminous part is an order of magnitude smaller yet. Particle dark matter, i.e., one or more relic particle species from the big bang, is thus strongly suggested as the dominant component of matter in the Universe. The axion, a hypothetical elementary pseudoscalar arising from the Peccei-Quinn solution to the strong-CP problem, is a well-motivated candidate. If the axion exists, it must be extremely light, in the mass range of 10-6–10-3 eV, and possess extraordinarily feeble couplings to matter and radiation. Nevertheless, as proposed by Sikivie in 1983, the axion’s two-photon coupling lends itself to a feasible search strategy with currently available technology. In this scheme, axions resonantly convert to single microwave photons by a Primakoff interaction, in a tunable microwave cavity permeated by a strong magnetic field. Present experiments utilizing heterostructure transistor microwave amplifiers have achieved total system noise temperatures of ?3 K and represent the world’s quietest spectral radio receivers. Exclusion regions have already been published well into the band of realistic axion model couplings, within the lowest decade of mass range. Recent breakthroughs in the development of near-quantum-limited superconducting quantum interference device amplifiers should reduce the system noise temperature to ?100 mK or less. Ongoing research into using Rydberg-atom single-quantum detectors as the detector in a microwave cavity experiment could further reduce the effective noise temperature. In parallel with improvements in amplifier technology, promising concepts for higher-frequency cavity resonators are being explored to open up the higher decades in mass range. Definitive experiments to find or exclude the axion may therefore be at hand in the next few years. As the microwave cavity technique measures the total energy of the axion, a positive discovery could well reveal fine structure of the signal due to flows of nonthermalized axions. Manifesting diurnal and sidereal modulation, such detailed features would contain a wealth of information about the history, structure, and dynamics of our Milky Way galaxy.

Richard Bradley; John Clarke; Darin Kinion; Leslie J Rosenberg; Karl van Bibber; Seishi Matsuki; Michael Mück; Pierre Sikivie

2003-06-12T23:59:59.000Z

442

An electronic radiation of blackbody: Cosmic electron background  

E-Print Network (OSTI)

The Universe owns the electronic radiation of blackbody at temperature 2.725 K, which we call the cosmic electron background. We calculate its radiation spectrum. The energy distribution of number density of electrons in the cosmic electron background becomes zero as energy goes to both zero and infinity. It has one maximum peak near the energy level of 10**(-23) J.

Jian-Miin Liu

2008-02-23T23:59:59.000Z

443

Background Long history of research and education in "nuclear  

E-Print Network (OSTI)

· Degradation Nuclear Materials · Multi physics modelling · Severe nuclear accidents · Non destructive testing#12;Background · Long history of research and education in "nuclear engineering" at Chalmers. · "Nuclear engineering" = multi-disciplinary research area. #12;Background Establishment of the Sustainable

Lemurell, Stefan

444

cognitive backgroundCIS4140-2 1 administrivia  

E-Print Network (OSTI)

Cognitive background human-computer interaction understand computer workings (reasonably well) how about humans? once part of psychology now considered cognitive science may also need some sociology later #12;cognitive backgroundCIS4140-2 4 perceptual 2 perceptions considered for UI auditory visual new interfaces

Damon, Craig A.

445

Low Background Radiation Experiment Yields Interesting Preliminary Results  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Low Background Radiation Experiment Yields Interesting Preliminary Low Background Radiation Experiment Yields Interesting Preliminary Results Low Background Radiation Experiment Yields Interesting Preliminary Results May 18, 2011 - 12:00pm Addthis Media Contact Deb Gill U.S. DOE Carlsbad Field Office (575) 234-7270 CARLSBAD, N.M. - New Mexico State University"s Low Background Radiation Experiment (LBRE), which takes place 2,150 feet below the earth"s surface at the Waste Isolation Pilot Plant, recently released some results about the project"s first two years of experimentation. The March 2011 edition of Health Physics printed an article titled "Exploring Biological Effects of Low Level Radiation from the Other Side of Background," summarizing some initial data taken from LBRE and from a sister experiment conducted at the Lovelace Respiratory Research Institute

446

After the Big Bang  

NLE Websites -- All DOE Office Websites (Extended Search)

After the Big Bang After the Big Bang Golden Age of Cosmology Big Bang Timeline Big Bang? Standard Big Bang Cosmology Slide 6 Big Bang Nucleosynthesis Redshift and Doppler Shift Doppler Shift Cepheid variables and Nebulae Standard Candles Hubble Expansion Hubble Law Cosmic Microwave Background Cosmic Background Explorer (1989-1993) COBE data/DMR CMB Fluctuations What is inflation? Why believe in inflation? Horizon Problem No inflation With inflation Flatness Problem Slide 24 Wilkinson Microwave Anisotropy Probe (2001-present) Fluctuations and geometry Universe's Baby Pictures Compare to COBE CMB vs. Inflation WMAP angular power spectrum Dark Matter Galaxy Rotation Curves Hot gas in Galaxy Clusters Dark Matter Halo Old view: Density of the Universe determines its destiny Hubble Expansion revisited

447

Connecting the Time Series of Microwave Sounding Observations from AMSU to ATMS for Long-Term Monitoring of Climate  

Science Journals Connector (OSTI)

The measurements from the Microwave Sounding Unit (MSU) and the Advanced Microwave Sounding Unit-A (AMSU-A) on board NOAA polar-orbiting satellites have been extensively utilized for detecting atmospheric temperature trend during the last several ...

Xiaolei Zou; Fuzhong Weng; H. Yang

2014-10-01T23:59:59.000Z

448

Modelling microwave cooking; theory and experiment C.J. Budd, Centre for Nonlinear Mechanics, University of Bath, UK,  

E-Print Network (OSTI)

is that they reveal that the fields in a typical microwave cavity (such as a domestic cooker) are very sensitive a microwave cooker and a scenario used for experimental testing is shown in Figure. ??. PICTURE OF THE COOKER

Burton, Geoffrey R.

449

Spinning Test Particle in Kalb-Ramond background  

E-Print Network (OSTI)

In this work we explore the geodesic deviations of spinning test particles in a string inspired Einstein-Kalb Ramond background. Such a background is known to be equivalent to a spacetime geometry with torsion. We have shown here that the antisymmetric Kalb-Ramond field has significant effect on the geodesic deviation of a spinning test particle. A search for an observational evidence of such an effect in astrophysical experiments may lead to a better undestanding of the geometry of the background spacetime.

Debaprasad Maity; Soumitra SenGupta; Sourav Sur

2005-05-19T23:59:59.000Z

450

Sakai-Sugimoto model in D0-D4 background  

Science Journals Connector (OSTI)

We add smeared D0 charges to the D4 background and discuss the Sakai-Sugimoto model under this background. The corresponding gauge theory is in a state with an expectation value of ?tr(F??F˜??)?. The D8-branes go less deep than in the original S-S model and massless Goldstones are still found in the spectrum. The effects of this condensate on the meson spectra, pion decay constant, and couplings of the vector mesons and Goldstones in this background state are then investigated.

Chao Wu; Zhiguang Xiao; Da Zhou

2013-07-22T23:59:59.000Z

451

Elemental analysis by microwave-assisted laser-induced breakdown spectroscopy: Evaluation on ceramics  

E-Print Network (OSTI)

,2 These sources are usually flames or plasmas: arcs, sparks, plasma jets, inductively coupled plasma (ICP), high demonstrated the signal enhancement ability of their LAMPS (Laser-Assisted Microwave Plasma Spectroscopy utilizing interaction between microwave radiation and laser-induced plasma has been evaluated. Experimental

Richardson, Martin C.

452

Microwave applicator for in-drum processing of radioactive waste slurry  

DOE Patents (OSTI)

A microwave applicator for processing of radioactive waste slurry uses a waveguide network which splits an input microwave of TE.sub.10 rectangular mode to TE.sub.01 circular mode. A cylindrical body has four openings, each receiving 1/4 of the power input. The waveguide network includes a plurality of splitters to effect the 1/4 divisions of power.

White, Terry L. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

453

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1  

E-Print Network (OSTI)

Microwave Photon Counter Based on Josephson Junctions Y.-F. Chen,1,* D. Hover,1 S. Sendelbach,1 L on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from optical photon counters, it is natural to consider the Josephson junction--a nonlinear, nondissipative

Saffman, Mark

454

Selective Conversion of Biomass Hemicellulose to Furfural Using Maleic Acid with Microwave Heating  

Science Journals Connector (OSTI)

Selective Conversion of Biomass Hemicellulose to Furfural Using Maleic Acid with Microwave Heating ... With the aim to develop an ecological method to convert xylose into furfural without the use of inorganic acids, a ... ... Sulfonated lignin was converted to phenol and phenolic compounds using a conventional batch or a microwave reactor. ...

Eurick S. Kim; Shuo Liu; Mahdi M. Abu-Omar; Nathan S. Mosier

2012-01-10T23:59:59.000Z

455

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock  

E-Print Network (OSTI)

Eric Moulton, Ferri Hassani, Pejman Nekoovaght Microwave-Assisted Heating in Rock INTRODUCTION to expensive replacements. Expansive heating through microwaves breaks up the rock, which reduces the stress the mechanisms and parameters governing the heating rate of a material. Department of Mining and Materials

Barthelat, Francois

456

Microwave and EUV Observations of an Erupting Filament and Associated Flare and Coronal Mass Ejections  

Science Journals Connector (OSTI)

......observes below 16 MHz that corresponds...to at least 30 kHz, well into the...feature was 5.51 MHz at 07:48 UT...High-Temperature Plasma to the Microwave...of a stratified atmosphere; then, the integrations...temperature plasma to the microwave...operating at 5743 MHz (5.2 cm......

Costas E. Alissandrakis; Alexey A. Kochanov; Spiros Patsourakos; Alexander T. Altyntsev; Sergey V. Lesovoi; Nadya N. Lesovoya

2013-12-05T23:59:59.000Z

457

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium Titanate  

E-Print Network (OSTI)

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium) with particle sizes ranging from 30 to 100 nm were synthesized via microwave-hydrothermal routes at various, but increased gradually with extended aging time in variable frequency (3-5.5 GHz to 1 s) processing

Dutta, Prabir K.

458

Microwave-assisted preparation of zeolite KH from alumatrane and Mathavee Sathupunya a  

E-Print Network (OSTI)

-loaded zeolite was synthesized for the first time, via sol­gel processing and microwave heating techniques Elsevier Inc. All rights reserved. Keywords: Alumatrane; Silatrane; Microwave technique; Sol­gel process; K by hydrothermal crystallization under alkaline conditions using an amorphous aluminosilicate gel as the starting

Gulari, Erdogan

459

Comparative study of microwave tomography segmentation techniques based on GMM and KNN in breast cancer detection  

Science Journals Connector (OSTI)

Microwave Tomography Imaging (MTI) is a new technology for early breast cancer detection. Compared to other methods such as X-ray, Magnetic Resonance Imaging (MRI) and ultrasound, the MTI technology is almost radiation-free, and low cost. However, the ... Keywords: gaussian mixture model, microwave tomography imaging, segmentation

Chunqiu Wang, Wei Wang, Sung Shin, Soon I. Jeon

2014-10-01T23:59:59.000Z

460

Method and apparatus for measuring butterfat and protein content using microwave absorption techniques  

DOE Patents (OSTI)

A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables. A differential technique using a second resonant cavity containing a reference standard as a sample will normalize the measurements from the unknown sample and thus be self-calibrating. A shuttered mechanism will switch the microwave excitation between the unknown and the reference cavities. An integrated apparatus for measuring the butterfat content in milk using microwave absorption techniques is also presented.

Fryer, Michael O. (Roberts, ID); Hills, Andrea J. (Iowa City, IA); Morrison, John L. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background cmb" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Microwave accelerated one-minute synthesis of luminescent ZnO quantum dots  

Science Journals Connector (OSTI)

In this paper we present microwave assisted non-aqueous synthesis of ZnO quantum dots (QDs) by hydrolyzing zinc acetate with lithium hydroxide in ethanol under microwave heating. The processing time for QDs was reduced to few minutes when compared with time consuming sol–gel chemistry. The prepared QDs show good colloidal stability along with stable visible emission.

Adersh Asok; A. R. Kulkarni; Mayuri N. Gandhi

2013-01-01T23:59:59.000Z

462

Experimental Study on Microwave Pyrolysis of an Indonesian Low-Rank Coal  

Science Journals Connector (OSTI)

Microwave pyrolysis of an Indonesian lignite is investigated in this study. ... About half of the world’s coal reserves are low-rank coals. ... Considerable amts. of 3,4-dihydro-1(2H)-naphthalenone (alpha-tetralone) were found in the oil fractions of lignites treated by microwave energy. ...

Nan Wang; Jianglong Yu; Arash Tahmasebi; Yanna Han; John Lucas; Terry Wall; Yu Jiang

2013-10-14T23:59:59.000Z

463

Design of a Microwave-Initiated Pulsed Plasma Thruster Jian F. Li, Class of 2006  

E-Print Network (OSTI)

and departments: · Prof. Edgar Choueiri of the Princeton University Electric Propulsion and Plasma Dynamics and Plasma Dynamics Laboratory. · Prof. Miles and Princeton Applied Physics Group for microwave leak detector of the Princeton University Electric Propulsion and Plasma Dynamics Laboratory for his insight into microwave

Choueiri, Edgar

464

Sub-degree Scale Microwave Anisotropies from Cosmic Defects  

E-Print Network (OSTI)

If current ideas about unified field theories are correct, macroscopic cosmic defects may well exist. The observation of such an entity would have enormous significance for our understanding of fundamental physics. This paper points out a novel observable signature of cosmic texture and global monopoles, namely strong hot spots in the cosmic microwave anisotropy pattern on subdegree scales. This signal should be readily detectable by the next generation of anisotropy mapping experiments. The signature arises from overdensities in the photon-baryon fluid generated by the gravitational attraction of the defects. The angular power spectrum of the anisotropy fluctuations on subdegree scales is also calculated, for cosmic string, global monopoles, and texture.

Neil Turok

1996-06-16T23:59:59.000Z

465

Nanoparticle plasma ejected directly from solid copper by localized microwaves  

SciTech Connect

A plasma column ejected directly from solid copper by localized microwaves is studied. The effect stems from an induced hotspot that melts and emits ionized copper vapors as a confined fire column. Nanoparticles of {approx}20-120 nm size were revealed in the ejected column by in situ small-angle x-ray scattering. Optical spectroscopy confirmed the dominance of copper particles in the plasma column originating directly from the copper substrate. Nano- and macroparticles of copper were verified also by ex situ scanning electron microscopy. The direct conversion of solid metals to nanoparticles is demonstrated and various applications are proposed.

Jerby, E.; Golts, A.; Shamir, Y.; Wonde, S.; Ashkenazi, D.; Eliaz, N. [Faculty of Engineering, Tel Aviv University, Ramat Aviv 69978 (Israel); Mitchell, J. B. A.; LeGarrec, J. L. [IPR., U.M.R. No. 6251 du C.N.R.S., Universite de Rennes I, 35042 Rennes (France); Narayanan, T.; Sztucki, M. [European Synchrotron Radiation Facility, BP-220, 38043 Grenoble (France); Barkay, Z. [Wolfson Applied Materials Research Center, Tel Aviv University, Ramat-Aviv 69978 (Israel)

2009-11-09T23:59:59.000Z

466

A 100-kc modulation system for an EPR microwave spectrometer  

E-Print Network (OSTI)

A 100-kc FIELD MODULATION SYSTEM FOR AN EPR MICROWAVE SPECTROMETER A Thesis By Frank Edwin Stewart Approved as to style and content by: /I i r Chairman of Committee C ead of Dep rtment Member ember August 1964 ACM ONLEDGi PENT... LIST OF FIGURES FIGURE PAGE II-1 Molecular Structure of DPPH 22 II-2 11-3 III-1 IV-1 Hyperfine Splitting in the DPPH EPR Spectrum . 25 Hyperfine Splitting in the Mn EpR Spectrum , . 27 100-kc Field Modulation and Detection System . 4I Typical...

Stewart, Frank Edwin

2012-06-07T23:59:59.000Z

467

One-way glass for microwaves using nonreciprocal metamaterials  

Science Journals Connector (OSTI)

We introduce a class of nonreciprocal metamaterials based on composite assemblies of metallic and biased ferrimagnetic elements. We show that such structures act as ultrathin one-way glasses due to the competition between two modes at the surface of the ferrimagnetic elements—a low-loss surface wave that transmits the signal on the other side of the structure and a surface spin-wave resonance that produces strong isolation levels. These findings can be adapted to existing metamaterial geometries, offering a blueprint to achieve unidirectional propagation in a variety of artificial media at radio, microwave, and millimeter wave frequencies.

A. Degiron and D. R. Smith

2014-05-27T23:59:59.000Z

468

Wide band cryogenic ultra-high vacuum microwave absorber  

DOE Patents (OSTI)

An absorber wave guide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the wave guide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the wave guide.

Campisi, Isidoro E. (Newport News, VA)

1992-01-01T23:59:59.000Z

469

A 2-MeV microwave thermionic gun  

SciTech Connect

A high-gradient, S-band microwave gun with a thermionic cathode is being developed in a collaborative effort by AET, Varian, and SSRL. A prototype design using an upgraded Varian dispenser cathode mounted with thermal isolation directly in the first half-cell of a 1-1/2 cell, side-coupled, standing-wave cavity has been fabricated and is being tested. Optimization of the cavity shape and beam formation was done using SUPERFISH, MASK, and PARMELA. An overview of design details, as well as the status of in-progress beam tests, will be presented. 9 refs., 6 figs.

Tanabe, E.; Borland, M.; Green, M.C.; Miller, R.H.; Nelson, L.V.; Weaver, J.N.; Wiedemann, H.

1989-08-01T23:59:59.000Z

470

Wide band cryogenic ultra-high vacuum microwave absorber  

DOE Patents (OSTI)

An absorber waveguide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the waveguide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the waveguide. 11 figs.

Campisi, I.E.

1992-05-12T23:59:59.000Z

471

Compact hot-nozzle fourier-transform microwave spectormeter  

E-Print Network (OSTI)

, the observed signal (the voltage at the input to the analog-to-digital converter (ADC), for example, see Fig. 2), may be written as Scc(~Qv>“~~!f(Po,To,D,r~,...), (2) where v,Q, and V are, respectively, the microwave frequency, quality factor... dipole moment for the resonant molecular states. For the Fabry-Perot cavity, Q scales with reflector separation (d),6 so (QV) r” introduces (I X Z3) “’ = I”, scaling with linear dimension 1. But in practice Q is often determined by input...

Harmony, Marlin D.; Ratzlaff, Kenneth L.; Angst, D. M.; Beren, K. A.

1995-11-01T23:59:59.000Z

472

Polycrystal diamond growth in a microwave plasma torch  

SciTech Connect

Diamond films of different structures were deposited on quartz, WC-Co, and molybdenum substrates in a microwave plasma torch discharge in an argon-hydrogen-methane gas mixture in a sealed chamber at pressures close to atmospheric by using the chemical vapor deposition technique. Images of diamond polycrystal films and separate crystals, as well as results of Raman spectroscopy, are presented. The spectra of optical plasma radiation recorded during film deposition demonstrate the presence of intense H{sub {alpha}} hydrogen and C{sub 2} radical bands known as Swan bands.

Sergeichev, K. F.; Lukina, N. A.; Bolshakov, A. P.; Ralchenko, V. G.; Arutyunyan, N. R.; Vlasov, I. I. [Russian Academy of Sciences, Prokhorov Institute of General Physics (Russian Federation)

2010-12-15T23:59:59.000Z

473

Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. X, No. Y, Month 2010 Numerical treatment of rounded and sharp  

E-Print Network (OSTI)

Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. X, No. Y, Month 2010 the corners for any value of . For a precise definition, refer to [2]. Brazilian Microwave and Optoelectronics in "journal of microwaves, optoelectronics and electromagnetic applications 10, 1 (2011) 66-81" DOI : 10

Boyer, Edmond

474

Microsoft PowerPoint - Microwave Off-gas srnlTechBriefp1.ppt  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Off-Gas Treatment Microwave Off-Gas Treatment System at a glance  simple design  compact and portable  easy to operate  can be remotely operated  low cost, low maintenance  scalable for large and small volume operations  U.S. patent 6,534,754 The Microwave Off-Gas Treatment System uses microwave energy and high temperatures to treat off- gas emissions to reduce contaminants to acceptable or nondetectable levels. This allows the treated gaseous waste stream to be safety discharged to the atmosphere. New method Scientists at Savannah River National Laboratory (SRNL), working with colleagues from the University of Florida (UF), have invented a unique system to treat off-gas emissions from safe discharge into the atmosphere. The compact and portable Microwave Off-Gas Treatment System is designed to

475

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.

1992-10-13T23:59:59.000Z

476

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN)

1992-01-01T23:59:59.000Z

477

Constraints on the microwave opacity of gaseous methane and water vapor in the Jovian atmosphere  

SciTech Connect

Gaseous NH/sub 3/'s microwave absorption in the Jovian atmosphere appears too great to be due to a solar abundance of this gas. The additional capacity of microwave absorption is presently sought in measurements of the microwave absorption of CH/sub 4/ and H/sub 2/O under simulated Jovian conditions at 2.25 GHz, 8.5 GHz, 21.7 GHz; due to large error bars, measurements represent upper limits on the microwave opacity generated by H/sub 2/O and CH/sub 4/. The results obtained are consistent with theoretical expressions for microwave opacity in a Jovian atmosphere at the specified frequencies. The presence of an NH/sub 3/ abundance exceeding the solar level by a factor of 1.5 is indicated by test results. 16 references.

Jenkins, J.M.; Steffes, P.G.

1988-11-01T23:59:59.000Z

478

Background gamma terrestrial dose rate in Nigerian functional coal mines  

Science Journals Connector (OSTI)

......444-448 (2003). 12. Nakaoka, A., Fukushima, M. and Shinji, T. Environmental...TERRESTRIAL DOSE RATE IN NIGERIAN MINES N d Aerial ropeway Figure 2. Surface background...444 448 (2003). 12. Nakaoka, A., Fukushima, M. and Shinji, T. Environmental......

C. E. Mokobia; F. A. Balogun

2004-01-01T23:59:59.000Z

479

EXTRAGALACTIC VERY HIGH ENERGY GAMMA-RAY BACKGROUND  

SciTech Connect

We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b| > 60 Degree-Sign . Subtracting photons associated with known sources and the residual cosmic-ray and Galactic diffuse backgrounds, we estimate the extragalactic gamma-ray background (EGB) flux. We find that the spectrum of EGB in the very high energy band above 30 GeV follows the stacked spectrum of BL Lac objects. Large Area Telescope data reveal the positive (1 + z) {sup k}, 1 < k < 4 cosmological evolution of the BL Lac source population consistent with that of their parent population, Fanaroff-Riley type I radio galaxies. We show that EGB at E > 30 GeV could be completely explained by emission from unresolved BL Lac objects if k {approx_equal} 3.

Neronov, A. [ISDC Data Center for Astrophysics, Chemin d'Ecogia 16, CH-1290 Versoix (Switzerland); Semikoz, D. V. [APC, 10 rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France)

2012-09-20T23:59:59.000Z

480

1 Mathematical Background 1 1.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . 1  

E-Print Network (OSTI)

Contents 1 Mathematical Background 1 1.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Computability Theory . . . . . . . . . . . . . . . . . . . . 4 1.3 Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4 Probability Theory . . . . . . . . . . . . . . . . . . . . . . 8 1.5 Exercises and Problems

Goodman, James R.

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481

1 Introduction 1 1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1  

E-Print Network (OSTI)

Contents 1 Introduction 1 1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Our Goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 ICSI's HMM/ANN Hybrid Speech Recognition System . . . . . . . . 2 1.4 What is Multi­band Processing

Mirghafori, N. Nikki

482

Inhomogeneous Background Error Modeling and Estimation over Antarctica  

Science Journals Connector (OSTI)

The structure of the analysis increments in a variational data assimilation scheme is strongly driven by the formulation of the background error covariance matrix, especially in data-sparse areas such as the Antarctic region. The gridpoint ...

Yann Michel; Thomas Auligné

2010-06-01T23:59:59.000Z

483

Lovelock black holes in a string cloud background  

E-Print Network (OSTI)

We present an exact static, spherically symmetric black hole solution to the third order Lovelock gravity with a string cloud background in seven dimensions for the special case when the second and third order Lovelock coefficients are related via $\\tilde{\\alpha}^2_2=3\\tilde{\\alpha}_3\\;(\\equiv\\alpha^2)$. Further, we examine thermodynamic properties of this black hole to obtain exact expressions for mass, temperature, entropy and also perform the thermodynamic stability analysis. We see that a string cloud background makes a profound influence on horizon structure, thermodynamic properties and the stability of black holes. Interestingly, the entropy of the black hole is unaffected due to a string cloud background. However, the critical solution for thermodynamic stability is being affected by a string cloud background.

Tae-Hun Lee; Dharmanand Baboolal; Sushant G. Ghosh

2014-09-12T23:59:59.000Z

484

QCD background for the UA1 W?tb¯ signal  

Science Journals Connector (OSTI)

The cc¯X and bb¯X background affecting the W?tb¯ e/?+2 jets signal reported by the UA1 Collaboration is discussed. Calculations are based on an O(?s 2)+leading-pole approximation scheme, which includes jet radiation in the initial and final states of the hard binary parton process, and include the heavy-flavor excitation contribution, the stability of which has been checked. The main conclusions are the following. (i) Selection cuts naturally induce a topological event structure on the surviving background mimicking that expected for a W?tb¯ signal. (ii) The background rates for ?+2 jets events, on which we concentrate, are compatible within theoretical uncertainties with the number of events experimentally observed. The importance of purely leptonic decay modes, which survive the lepton-isolation cuts, and the bias induced by lepton-isolation cuts on background event topologies are also clarified.

A. Grosso and R. Odorico

1985-12-01T23:59:59.000Z

485

GammaSense: Infrastructureless Positioning Using Background Radioactivity  

Science Journals Connector (OSTI)

We introduce the harvesting of natural background radioactivity for positioning. Using a standard Geiger-Müller counter as sensor, we fingerprint the natural levels of gamma radiation with the aim of then roughly pinpointing the position of a client ...

Doina Bucur; Mikkel Baun Kjærgaard

2008-10-01T23:59:59.000Z

486

Simulation of PEP-II Accelerator Backgrounds Using TURTLE  

SciTech Connect

We present studies of accelerator-induced backgrounds in the BaBar detector at the SLAC B-Factory, carried out using LPTURTLE, a modified version of the DECAY TURTLE simulation package. Lost-particle backgrounds in PEP-II are dominated by a combination of beam-gas bremstrahlung, beam-gas Coulomb scattering, radiative-Bhabha events and beam-beam blow-up. The radiation damage and detector occupancy caused by the associated electromagnetic shower debris can limit the usable luminosity. In order to understand and mitigate such backgrounds, we have performed a full program of beam-gas and luminosity-background simulations, that include the effects of the detector solenoidal field, detailed modeling of limiting apertures in both collider rings, and optimization of the betatron collimation scheme in the presence of large transverse tails.

Barlow, R.J.; Fieguth, T.; /SLAC; Kozanecki, W.; /DSM, DAPNIA, Saclay; Majewski, S.A.; /Stanford U., Phys. Dept.; Roudeau, P.; Stocchi, A.; /Orsay, LAL

2006-02-15T23:59:59.000Z

487

The Cosmic Near Infrared Background: Remnant Light from Early Stars  

E-Print Network (OSTI)

The redshifted ultraviolet light from early stars at z ~ 10 contributes to the cosmic near infrared background. We present detailed calculations of its spectrum with various assumptions about metallicity and mass spectrum of early stars. We show that if the near infrared background has a stellar origin, metal-free stars are not the only explanation of the excess near infrared background; stars with metals (e.g. Z=1/50 Z_sun) can produce the same amount of background intensity as the metal-free stars. We quantitatively show that the predicted average intensity at 1-2 microns is essentially determined by the efficiency of nuclear burning in stars, which is not very sensitive to metallicity. We predict \

Elizabeth Fernandez; Eiichiro Komatsu

2005-08-08T23:59:59.000Z

488

Muon-Induced Backgrounds in Double Chooz Emily Conover  

E-Print Network (OSTI)

to scintillator 8 MeV n capture energy, 30µs backgrounds due to muons remain E¯e = Ee+ + 10-40keV En + 1.8MeMuon-Induced Backgrounds in Double Chooz Emily Conover University of Chicago Second Thesis and Stopped Muons 9Li and 8He 3. Double Chooz Results 4. Conclusions Timeline/Future work Emily Conover (Univ

489

The X-ray background and the evolution of AGN  

E-Print Network (OSTI)

We discuss the constraints on the AGN evolution from the cosmic X-ray background and source counts. A synthesis model to fit the X-ray background is presented. In the model, the spectrum of type 2 AGN has been modeled including Compton down--scattering within the absorbing material. Besides, we introduced a dependence on redshift of the relative number of obscured sources and found a decrease of the fraction of type 2 AGN at redshifts larger than 2.

Fulvio Pompilio; Fabio La Franca; Giorgio Matt

1999-09-23T23:59:59.000Z

490

Muon-induced backgrounds in the CUORICINO experiment  

E-Print Network (OSTI)

To better understand the contribution of cosmic ray muons to the CUORICINO background, 10 plastic scintillator detectors were installed at the CUORICINO site and operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV kg yr) (95% CL) was obtained on the cosmic ray-induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.

E. Andreotti; C. Arnaboldi; F. T. Avignone III; M. Balata; I. Bandac; M. Barucci; J. W. Beeman; F. Bellini; T. Bloxham; C. Brofferio; A. Bryant; C. Bucci; L. Canonica; S. Capelli; L. Carbone; M. Carrettoni; M. Clemenza; O. Cremonesi; R. J. Creswick; S. Di Domizio; M. J. Dolinski; L. Ejzak; R. Faccini; H. A. Farach; E. Ferri; F. Ferroni; E. Fiorini; L. Foggetta; A. Giachero; L. Gironi; A. Giuliani; P. Gorla; E. Guardincerri; T. D. Gutierrez; E. E. Haller; R. Kadel; K. Kazkaz; S. Kraft; L. Kogler; Yu. G. Kolomensky; C. Maiano; R. H. Maruyama; C. Martinez; M. Martinez; L. Mizouni; S. Morganti; S. Nisi; C. Nones; E. B. Norman; A. Nucciotti; F. Orio; M. Pallavicini; V. Palmieri; L. Pattavina; M. Pavan; M. Pedretti; G. Pessina; S. Pirro; E. Previtali; L. Risegari; C. Rosenfeld; C. Rusconi; C. Salvioni; S. Sangiorgio; D. Schaeffer; N. D. Scielzo; M. Sisti; A. R. Smith; C. Tomei; G. Ventura; M. Vignati

2009-12-18T23:59:59.000Z

491

Kinematic interpretation of string instability in a background gravitational field  

Science Journals Connector (OSTI)

The unstable regime in which the string oscillating modes develop imaginary frequencies is shown to be characterized, kinematically, by a positive relative acceleration among the different points of the string. Instability occurs when this acceleration, induced by the background curvature, is large enough to make the extension of the corresponding causally connected region smaller than the string maximal size. This kinematic characterization is applied, in particular, to discuss string instability in a static and spherically symmetric gravitational background.

M. Gasperini

1991-01-01T23:59:59.000Z

492

Background reduction and sensitivity for germanium double beta decay experiments  

E-Print Network (OSTI)

Germanium detectors have very good capabilities for the investigation of rare phenomena like the neutrinoless double beta decay. Rejection of the background entangling the expected signal is one primary goal in this kind of experiments. Here, the attainable background reduction in the energy region where the neutrinoless double beta decay signal of 76Ge is expected to appear has been evaluated for experiments using germanium detectors, taking into consideration different strategies like the granularity of the detector system, the segmentation of each individual germanium detector and the application of Pulse S