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1

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

2

A New Upper Limit on the Polarization of the Cosmic Microwave Background Radiation  

E-Print Network [OSTI]

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological parameters, such as the curvature of the universe, the shape of the spectrum of primordial density fluctuations, and the contribution of baryons, dark matter, and dark energy to the overall energy density of the universe. In addition to being spatially non-uniform, the CMB is theorized to be slightly polarized. Measurements of this polarization, particularly at large angular scales, have the potential to provide information on primordial gravitational waves, theories of inflation, and the ionization history of the universe, as well as help further constrain cosmological parameters. Polarization has not yet been detected in the CMB. This thesis describes a recent search for CMB polarization at large angular scales, conducted in the spring of 2000 at the University of Wisconsin-Madison. After a general introduction on both CMB polarization and general microwave polarimetry, details of the experiment itself are given, as well as a full description of the data selection and analysis techniques. Using these techniques, our data lead to a new upper limit on CMB polarization at large angular scales of 10 $\\mu$K in both E- and B-type polarization at 95% confidence. If B-polarization is assumed to be zero, the limit for E-type polarization is lowered to 8 $\\mu$K. This experiment is the first of a new breed of highly-sensitive instruments that will one day map out this interesting property of the Cosmic Microwave Background Radiation.

Christopher O'Dell

2002-01-15T23:59:59.000Z

3

Are you sure that the anisotropies in the microwave background radiation are really cosmological rather than purely Galactic in origin?  

E-Print Network [OSTI]

New calculations of the Galactic contamination over microwave background radiation anisotropies are carried out. On one hand, when a frequency-dependent contrast of molecular clouds with respect to the Galactic background of the diffuse interstellar medium is taken into account, the anisotropic amplitude produced by Galactic dust is increased with respect to previous calculations and this is of the same order as that of the data from the observations. On the other hand, if we take into account rotational dust emission, for instance, a frequency independence of anisotropies in the microwave range may be obtained. This leads to the possibility that under some particular, but not impossible, conditions all the microwave background radiation anisotropies may be due to Galactic foregrounds rather than cosmological in origin. Moreover, a suspected coincidence between the typical angular sizes of the microwave background radiation anisotropies and those of nearby molecular clouds makes more plausible the hypothesis of a purely Galactic origin for these anisotropies. It is also argued that the correlation among structures at different frequencies, the comparison of the power spectrum at different frequencies and the galactic latitude dependence of the anisotropies are not yet proofs in favour of either a cosmological or Galactic origin.

M. Lopez-Corredoira

1999-05-01T23:59:59.000Z

4

Cosmic Microwave Background Polarization  

E-Print Network [OSTI]

Cosmic microwave background (CMB) anisotropy is our richest source of cosmological information; the standard cosmological model was largely established thanks to study of the temperature anisotropies. By the end of the decade, the Planck satellite will close this important chapter and move us deeper into the new frontier of polarization measurements. Numerous ground--based and balloon--borne experiments are already forging into this new territory. Besides providing new and independent information on the primordial density perturbations and cosmological parameters, polarization measurements offer the potential to detect primordial gravity waves, constrain dark energy and measure the neutrino mass scale. A vigorous experimental program is underway worldwide and heading towards a new satellite mission dedicated to CMB polarization.

James G. Bartlett

2006-04-18T23:59:59.000Z

5

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

6

The Cosmic Background Radiation  

E-Print Network [OSTI]

We summarise the current status of cosmic microwave background spectrum and anisotropy measurements, and their theoretical interpretation. This is the update of the mini-review for the 1997 web-version of the Review of Particle Properties.

George Smoot; Douglas Scott

1997-11-08T23:59:59.000Z

7

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

8

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

9

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

10

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

11

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

12

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

13

Illuminating the background : topics in cosmic microwave background polarization research  

E-Print Network [OSTI]

results in electric dipole radiation. For an unpolarizedincom- ing radiation. Because the electric field oscillates,

Miller, Nathan James

2012-01-01T23:59:59.000Z

14

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

15

Cosmic Microwave Background Anisotropy Window Functions Revisited  

E-Print Network [OSTI]

The primary results of most observations of cosmic microwave background (CMB) anisotropy are estimates of the angular power spectrum averaged through some broad band, called band-powers. These estimates are in turn what are used to produce constraints on cosmological parameters due to all CMB observations. Essential to this estimation of cosmological parameters is the calculation of the expected band-power for a given experiment, given a theoretical power spectrum. Here we derive the "band power" window function which should be used for this calculation, and point out that it is not equivalent to the window function used to calculate the variance. This important distinction has been absent from much of the literature: the variance window function is often used as the band-power window function. We discuss the validity of this assumed equivalence, the role of window functions for experiments that constrain the power in {\\it multiple} bands, and summarize a prescription for reporting experimental results. The analysis methods detailed here are applied in a companion paper to three years of data from the Medium Scale Anisotropy Measurement.

Lloyd Knox

1999-09-28T23:59:59.000Z

16

Fractal Structure of Isothermal Lines and Loops on the Cosmic Microwave Background  

E-Print Network [OSTI]

Fractal Structure of Isothermal Lines and Loops on the Cosmic Microwave Background Naoki KOBAYASHI and the fractal structure is confirmed in the radiation temperature fluctuation. We estimate the fractal exponents, such as the fractal dimension De of the entire pattern of isothermal lines, the fractal dimension Dc of a single

Chiang, Lung-Yih

17

DarkLight radiation backgrounds  

SciTech Connect (OSTI)

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

18

Statistical Isotropy of the Cosmic Microwave Background Anisotropy  

E-Print Network [OSTI]

Statistical Isotropy of the Cosmic Microwave Background Anisotropy Amir Hajian #3; I.U.C.A.A., Pune to be statistically isotropic, i.e., statistical expectation values of the temperature #29;uctuations are preserved under rotations of the sky. Only under statistical isotropy does the widely used angular power spectrum

Souradeep, Tarun

19

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

20

Global, exact cosmic microwave background data analysis using Gibbs sampling  

SciTech Connect (OSTI)

We describe an efficient and exact method that enables global Bayesian analysis of cosmic microwave background (CMB) data. The method reveals the joint posterior density (or likelihood for flat priors) of the power spectrum C{sub l} and the CMB signal. Foregrounds and instrumental parameters can be simultaneously inferred from the data. The method allows the specification of a wide range of foreground priors. We explicitly show how to propagate the non-Gaussian dependency structure of the C{sub l} posterior through to the posterior density of the parameters. If desired, the analysis can be coupled to theoretical (cosmological) priors and can yield the posterior density of cosmological parameter estimates directly from the time-ordered data. The method does not hinge on special assumptions about the survey geometry or noise properties, etc., It is based on a Monte Carlo approach and hence parallelizes trivially. No trace or determinant evaluations are necessary. The feasibility of this approach rests on the ability to solve the systems of linear equations which arise. These are of the same size and computational complexity as the map-making equations. We describe a preconditioned conjugate gradient technique that solves this problem and demonstrate in a numerical example that the computational time required for each Monte Carlo sample scales as n{sub p}{sup 3/2} with the number of pixels n{sub p}. We use our method to analyze the data from the Differential Microwave Radiometer on the Cosmic Background Explorer and explore the non-Gaussian joint posterior density of the C{sub l} from the Differential Microwave Radiometer on the Cosmic Background Explorer in several projections.

Wandelt, Benjamin D. [Department of Physics, UIUC, 1110 W Green Street, Urbana, Illinois 61801 (United States); Department of Astronomy, UIUC, 1002 W Green Street, Urbana, Illinois 61801 (United States); Larson, David L.; Lakshminarayanan, Arun [Department of Physics, UIUC, 1110 W Green Street, Urbana, Illinois 61801 (United States)

2004-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Translational invariance and the anisotropy of the cosmic microwave background  

SciTech Connect (OSTI)

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

22

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

23

Extracting cosmic microwave background polarisation from satellite astrophysical maps  

E-Print Network [OSTI]

We present the application of the Fast Independent Component Analysis technique for blind component separation to polarised astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarised signal, consisting of $E$ and $B$ modes, can be extracted from maps affected by substantial contamination from diffuse Galactic foregrounds and instrumental noise. We perform the analysis of all sky maps simulated accordingly to the nominal performances of the Low Frequency Instrument (LFI) aboard the Planck satellite; the sky signal is modeled as a superposition of CMB, generated by a Gaussian, nearly scale invariant cosmological perturbation spectrum, and the existing simulated polarisation templates of Galactic synchrotron. Our results indicate that the angular power spectrum of CMB $E$ modes can be recovered on all scales up to $\\ell\\simeq 1000$, corresponding to the fourth acoustic oscillation, while $B$ modes can be detected, up to their turnover at $\\ell\\simeq 100$ if cosmological tensor amplitude...

Baccigalupi, C; De Zotti, G; Smoot, G F; Burigana, C; Maino, D; Bedini, L; Salerno, E

2002-01-01T23:59:59.000Z

24

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

25

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

26

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

27

Detectability of Inflationary Gravitational Waves with Microwave Background Polarization  

E-Print Network [OSTI]

Inflation predicts specific relations between the amplitudes and spectral indices of the primordial spectrum of density (scalar metric) perturbations and gravitational waves (tensor metric perturbations). Detection of a stochastic gravitational-wave background is essential for identifying this unmistakable signature. Polarization of the cosmic microwave background can isolate these tensor modes in a model-independent way and thereby circumvent the cosmic-variance limit to detecting a small tensor signal with only a temperature map. Here we assess the detectability of a gravity-wave background with a temperature and polarization map. For detector sensitivities better than $10-20 \\mu K \\sqrt{sec}$, the sensitivity to a tensor signal is always dominated by the polarization map. With a detector sensitivity of order $1 \\mu K \\sqrt{sec}$, polarization could improve on a temperature-map sensitivity to tensor modes by two to three orders of magnitude. Even a small amount of reionization substantially enhances tensor-mode detectability. We also argue that the sensitivity of the Planck Surveyor to tensor modes is significantly improved with polarization, even taking into account the resulting degradation of the intensity determination in the high-frequency channels.

Marc Kamionkowski; Arthur Kosowsky

1997-05-28T23:59:59.000Z

28

Cosmological Rotation of Quantum-Mechanical Origin and Anisotropy of the Microwave Background  

E-Print Network [OSTI]

It is shown that rotational cosmological perturbations can be generated in the early Universe, similarly to gravitational waves. The generating mechanism is quantum-mechanical in its nature, and the created perturbations should now be placed in squeezed vacuum quantum states. The physical conditions under which the phenomenon can occur are formulated. The generated perturbations can contribute to the large-angular-scale anisotropy of the cosmic microwave background radiation. An exact formula is derived for the angular correlation function of the temperature variations caused by the quantum-mechanically generated rotational perturbations. The multipole expansion begins from the dipole component. The comparison with the case of gravitational waves is made.

L. P. Grishchuk

1993-10-06T23:59:59.000Z

29

Cosmic Background Radiation Due to Photon Condensation  

E-Print Network [OSTI]

It is shown that a collection of photons with nearly the same frequency exhibits a Bose "condensation" type of phenomenon at about 3 degrees K corresponding to a peak intensity at a wave length of about 0.4cm. This could give a mechanism for the observed Cosmic Background Radiation, and also explain some curious features.

B. G. Sidharth

1998-06-10T23:59:59.000Z

30

B2FH, the Cosmic Microwave Background and Cosmology  

E-Print Network [OSTI]

In this talk I shall start by describing how we set about and carried out the work which led to the publication of B2FH in 1957. I then shall try and relate this work and the circumstances that surrounded it to the larger problem of the origin and formation of the universe. Here it is necessary to look back at the way that ideas developed and how in many situations astronomers went astray. Of course this is a personal view, though I very strongly believe that if he were still here, it is the approach that Fred Hoyle would take. I start by describing the problems originally encountered by Gamow and his associates in trying to decide where the helium was made. This leads me to a modern discussion of the origin of 2D, 3He, 4He and 7Li, originally described by B2FH as due to the x-process. While it is generally argued, following Gamow, Alpher, and Herman, that these isotopes were synthesized in a big bang I shall show that it is equally likely that these isotopes were made in active galactic nuclei, as was the cosmic microwave background (CMB), in a cyclic universe model. The key piece of observational evidence is that the amount of energy carried by the CMB, namely about 4.5 x 10-13 erg cm-3

G. Burbidge

2008-07-24T23:59:59.000Z

31

Extracting cosmic microwave background polarisation from satellite astrophysical maps  

E-Print Network [OSTI]

We present the application of the Fast Independent Component Analysis ({\\ica}) technique for blind component separation to polarized astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarized signal, consisting of $E$ and $B$ modes, can be extracted from maps affected by substantial contamination from diffuse Galactic foreground emission and instrumental noise. {We implement Monte Carlo chains varying the CMB and noise realizations in order to asses the average capabilities of the algorithm and their variance.} We perform the analysis of all sky maps simulated according to the {\\sc Planck} satellite capabilities, modelling the sky signal as a superposition of the CMB and of the existing simulated polarization templates of Galactic synchrotron. Our results indicate that the angular power spectrum of CMB $E$-mode can be recovered on all scales up to $\\ell\\simeq 1000$, corresponding to the fourth acoustic oscillation, while the $B$-mode power spectrum can be detected, up to its turnover at $\\ell\\simeq 100$, if the ratio of tensor to scalar contributions to the temperature quadrupole exceeds 30%. The power spectrum of the cross correlation between total intensity and polarization, $TE$, can be recovered up to $\\ell\\simeq 1200$, corresponding to the seventh $TE$ acoustic oscillation.

C. Baccigalupi; F. Perrotta; G. De Zotti; G. F. Smoot; C. Burigana; D. Maino; L. Bedini; E. Salerno

2004-07-12T23:59:59.000Z

32

Extracting cosmic microwave background polarization from satelliteastrophysical maps  

SciTech Connect (OSTI)

We present the application of the fast independent component analysis (FASTICA) technique for blind component separation to polarized astrophysical emission. We study how the cosmic microwave background (CMB) polarized signal, consisting of E and B modes, can be extracted from maps affected by substantial contamination from diffuse Galactic foreground emission and instrumental noise. We implement Monte Carlo chains varying the CMB and noise realizations in order to assess the average capabilities of the algorithm and their variance. We perform the analysis of all-sky maps simulated according to the Planck satellite capabilities, modeling the sky signal as a superposition of the CMB and of the existing simulated polarization templates of Galactic synchrotron. Our results indicate that the angular power spectrum of CMB E mode can be recovered on all scales up to lsimilar or equal to 1000, corresponding to the fourth acoustic oscillation, while the B-mode power spectrum can be detected, up to its turnover at lsimilar or equal to 100, if the ratio of tensor to scalar contributions to the temperature quadrupole exceeds 30 per cent. The power spectrum of the cross-correlation between total intensity and polarization, TE, can be recovered up to lsimilar or equal to 1200, corresponding to the seventh TE acoustic oscillation.

Baccigalpi, C.; Perrotta, F.; Zotti, G.D.; Smoot, G.F.; Burigana,C.; Maino, D.; Bedini, L.; Salerno, E.

2004-05-02T23:59:59.000Z

33

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

34

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

35

A COSMIC MICROWAVE BACKGROUND LENSING MASS MAP AND ITS CORRELATION WITH THE COSMIC INFRARED BACKGROUND  

SciTech Connect (OSTI)

We use a temperature map of the cosmic microwave background (CMB) obtained using the South Pole Telescope at 150 GHz to construct a map of the gravitational convergence to z {approx} 1100, revealing the fluctuations in the projected mass density. This map shows individual features that are significant at the {approx}4{sigma} level, providing the first image of CMB lensing convergence. We cross-correlate this map with Herschel/SPIRE maps covering 90 deg{sup 2} at wavelengths of 500, 350, and 250 {mu}m. We show that these submillimeter (submm) wavelength maps are strongly correlated with the lensing convergence map, with detection significances in each of the three submm bands ranging from 6.7{sigma} to 8.8{sigma}. We fit the measurement of the cross power spectrum assuming a simple constant bias model and infer bias factors of b = 1.3-1.8, with a statistical uncertainty of 15%, depending on the assumed model for the redshift distribution of the dusty galaxies that are contributing to the Herschel/SPIRE maps.

Holder, G. P.; De Haan, T.; Dobbs, M. A.; Dudley, J. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); Viero, M. P.; Bock, J. [California Institute of Technology, Pasadena, CA 91125 (United States); Zahn, O. [Berkeley Center for Cosmological Physics, Department of Physics, University of California, and Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States); Benson, B. A.; Bhattacharya, S.; Bleem, L. E.; 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); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Cho, H-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States); Conley, A. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); George, E. M. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Halverson, N. W. [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); and others

2013-07-01T23:59:59.000Z

36

apm background radiation: Topics by E-print Network  

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

Extragalactic Background Radiation Astrophysics (arXiv) Summary: Attenuation of high--energy gamma rays by pair--production with UV, optical and IR background photons provides a...

37

POLARIZATION OF THE COSMIC BACKGROUND RADIATION  

E-Print Network [OSTI]

a 45° angle. Radiation whose electric field (polarization)radiation field, it can be uniquely characterized by its electric

Lubin, Philip Lubin

2010-01-01T23:59:59.000Z

38

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

39

Neural networks and separation of Cosmic Microwave Background and astrophysical signals in sky maps  

E-Print Network [OSTI]

The Independent Component Analysis (ICA) algorithm is implemented as a neural network for separating signals of different origin in astrophysical sky maps. Due to its self-organizing capability, it works without prior assumptions on the signals, neither on their frequency scaling, nor on the signal maps themselves; instead, it learns directly from the input data how to separate the physical components, making use of their statistical independence. To test the capabilities of this approach, we apply the ICA algorithm on sky patches, taken from simulations and observations, at the microwave frequencies, that are going to be deeply explored in a few years on the whole sky, by the Microwave Anisotropy Probe (MAP) and by the {\\sc Planck} Surveyor Satellite. The maps are at the frequencies of the Low Frequency Instrument (LFI) aboard the {\\sc Planck} satellite (30, 44, 70 and 100 GHz), and contain simulated astrophysical radio sources, Cosmic Microwave Background (CMB) radiation, and Galactic diffuse emissions from thermal dust and synchrotron. We show that the ICA algorithm is able to recover each signal, with precision going from 10% for the Galactic components to percent for CMB; radio sources are almost completely recovered down to a flux limit corresponding to $0.7\\sigma_{CMB}$, where $\\sigma_{CMB}$ is the rms level of CMB fluctuations. The signal recovering possesses equal quality on all the scales larger then the pixel size. In addition, we show that the frequency scalings of the input signals can be partially inferred from the ICA outputs, at the percent precision for the dominant components, radio sources and CMB.

C. Baccigalupi; L. Bedini; C. Burigana; G. De Zotti; A. Farusi; D. Maino; M. Maris; F. Perrotta; E. Salerno; L. Toffolatti; A. Tonazzini

2000-06-21T23:59:59.000Z

40

ESnet supports Sandia and APNIC IPv6 Background Radiation research  

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

Note: This page contains sample records for the topic "microwave background radiation" 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.


41

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

42

Effect of microwave radiation on Jayadhar cotton fibers: WAXS studies  

SciTech Connect (OSTI)

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

43

TACMB-1: The Theory of Anisotropies in the Cosmic Microwave Background (Bibliographic Resource Letter)  

E-Print Network [OSTI]

This Resource Letter provides a guide to the literature on the theory of anisotropies in the cosmic microwave background. Journal articles, web pages, and books are cited for the following topics: discovery, cosmological origin, early work, recombination, general CMB anisotropy references, primary CMB anisotropies (numerical, analytical work), secondary effects, Sunyaev-Zel'dovich effect(s), lensing, reionization, polarization, gravity waves, defects, topology, origin of fluctuations, development of fluctuations, inflation and other ties to particle physics, parameter estimation, recent constraints, web resources, foregrounds, observations and observational issues, and gaussianity.

Martin White; J. D. Cohn

2002-03-07T23:59:59.000Z

44

Low Background Radiation Experiment Yields Interesting Preliminary Results  

Broader source: Energy.gov [DOE]

CARLSBAD, N.M., May 18, 2011 – 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.

45

Position sensitive detection of neutrons in high radiation background field  

SciTech Connect (OSTI)

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high ? and e{sup ?} radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 ?m{sup 2}) spectroscopic Timepix detector adapted for neutron detection utilizing very thin {sup 10}B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10{sup ?4}.

Vavrik, D., E-mail: vavrik@itam.cas.cz [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, Prague (Czech Republic); Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9 (Czech Republic); Jakubek, J.; Pospisil, S. [Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9 (Czech Republic)] [Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9 (Czech Republic); Vacik, J. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, 250 68 Prague, Czech Republic (Czech Republic)] [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, 250 68 Prague, Czech Republic (Czech Republic)

2014-01-15T23:59:59.000Z

46

Radiative emission of neutrino pair free of quantum electrodynamic backgrounds  

E-Print Network [OSTI]

A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.

M. Yoshimura; N. Sasao; M. Tanaka

2015-01-23T23:59:59.000Z

47

Radiative emission of neutrino pair free of quantum electrodynamic backgrounds  

E-Print Network [OSTI]

A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.

Yoshimura, M; Tanaka, M

2015-01-01T23:59:59.000Z

48

LACK OF ANGULAR CORRELATION AND ODD-PARITY PREFERENCE IN COSMIC MICROWAVE BACKGROUND DATA  

SciTech Connect (OSTI)

We have investigated the angular correlation in the recent cosmic microwave background data. In addition to the known large-angle correlation anomaly, we find the lack of correlation at small angles with high statistical significance. We have investigated various non-cosmological contamination as well as the Wilkinson Microwave Anisotropy Probe (WMAP) team's simulated data. However, we have not found a definite cause. In the angular power spectrum of WMAP data, there exists anomalous odd-parity preference at low multipoles. Noting the equivalence between the power spectrum and the correlation, we have investigated the association between the lack of large-angle correlation and the odd-parity preference. From our investigation, we find that the odd-parity preference at low multipoles is, in fact, a phenomenological origin of the lack of large-angle correlation. Further investigation is required to find out whether the origin of the anomaly is cosmological or due to unaccounted systematics. The data from the Planck surveyor, which has systematics distinct from WMAP, will greatly help us to resolve its origin.

Kim, Jaiseung; Naselsky, Pavel, E-mail: jkim@nbi.dk [Niels Bohr Institute and Discovery Center, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)

2011-10-01T23:59:59.000Z

49

Radiation shielding for underground low-background experiments  

E-Print Network [OSTI]

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.

D. Y Stewart; P. F. Harrison; B. Morgan; Y. A. Ramachers

2006-07-31T23:59:59.000Z

50

The Second Peak: The Dark-Energy Density and the Cosmic Microwave Background  

E-Print Network [OSTI]

Supernova evidence for a negative-pressure dark energy (e.g., cosmological constant or quintessence) that contributes a fraction $\\Omega_\\Lambda\\simeq0.7$ of closure density has been bolstered by the discrepancy between the total density, $\\Omega_{\\rm tot}\\simeq1$, suggested by the location of the first peak in the cosmic microwave background (CMB) power spectrum and the nonrelativistic-matter density $\\Omega_m\\simeq0.3$ obtained from dynamical measurements. Here we show that the impending identification of the location of the {\\it second} peak in the CMB power spectrum will provide an immediate and independent probe of the dark-energy density. As an aside, we show how the measured height of the first peak probably already points toward a low matter density and places upper limits to the reionization optical depth and gravitational-wave amplitude.

Marc Kamionkowski; Ari Buchalter

2000-01-05T23:59:59.000Z

51

A Statistic for the Detection of Long Strings in Microwave Background Maps  

E-Print Network [OSTI]

Using analytical methods and Monte Carlo simulations, we analyze a new statistic designed to detect isolated step-like discontinuities which are coherent over large areas of Cosmic Microwave Background (CMB) pixel maps. Such coherent temperature discontinuities are predicted by the Kaiser-Stebbins effect to form due to long cosmic strings present in our present horizon. The background of the coherent step-like seed is assumed to be a scale invariant Gaussian random field which could have been produced by a superposition of seeds on smaller scales and/or by inflationary quantum fluctuations. The effects of uncorrelated Gaussian random noise are also studied. The statistical variable considered is the Sample Mean Difference (SMD) between large neighbouring sectors of CMB maps, separated by a straight line in two dimensional maps and a point in one dimensional maps. We find that including noise, the SMD statistics can detect at the $1 \\sigma$ to $2 \\sigma$ level the presense of a long string with $G\\mu (v_s \\gamma_s)= 1/(8\\pi) ((\\delta T)/T)_{rms} \\simeq 0.5 \\times 10^{-7}$ while more conventional statistics like the skewness or the kurtosis require a value of $G\\mu$ almost an order of magnitude larger for detectability at a comparable level.

Leandros Perivolaropoulos

1997-04-01T23:59:59.000Z

52

Electromagnetic radiation in a time-varying background medium  

E-Print Network [OSTI]

Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive function of time. As might be expected, such a medium introduces significant spectral shifts and spatio-temporal modulation, which are analized here for the linear and exponential time-variations of the medium parameters. In the varying-impedance case the solution is obtained for the fourth-order polynomial time-dependence of the permittivity. In addition to the spectral shifts and modulation this spatially homogeneous medium scatters the field introducing causal echoes at the receiver location.

Budko, Neil V

2009-01-01T23:59:59.000Z

53

Microwave radiative transfer in the mixed-phase regions of tropical rainfall  

E-Print Network [OSTI]

on an RTM. To accomplish this, we examined data taken by the Convair-580 aircraft during the KWAJEX (Kwajalein Experiment). In order to calculate radiative transfer, the AMMR (Airborne Multi-channel Microwave Radiometer) data were combined with radiosonde...

Jin, Kyoung-Wook

2001-01-01T23:59:59.000Z

54

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

55

Nonlinear Evolution of Cosmic Magnetic Fields and Cosmic Microwave Background Anisotropies  

E-Print Network [OSTI]

In this work we investigate the effects of the primordial magnetic fields on cosmic microwave background anisotropies (CMB). Based on cosmological magnetohydrodynamic (MHD) simulations we calculate the CMB anisotropy spectra and polarization induced by fluid fluctuations (Alfv\\'en modes) generated by primordial magnetic fields. The strongest effect on the CMB spectra comes from the transition epoch from a turbulent regime to a viscous regime. The balance between magnetic and kinetic energy until the onset of the viscous regime provides a one to one relation between the comoving coherence length $L$ and the comoving magnetic field strength $B$, such as $L \\sim 30 (B/10^{-9}{\\rm G})^3 \\rm pc$. The resulting CMB temperature and polarization anisotropies are somewhat different from the ones previously obtained by using linear perturbation theory. Our calculation gives a constraint on the magnetic field strength in the intermediate scale of CMB observations. Upper limits are set by WMAP and BOOMERANG results for comoving magnetic field strength of $B 0.7 \\rm Mpc$ for the most extreme case, or $B 0.8 \\rm Mpc$ for the most conservative case.

Hiroyuki Tashiro; Naoshi Sugiyama; Robi Banerjee

2006-01-14T23:59:59.000Z

56

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

57

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

SciTech Connect (OSTI)

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

58

Measurements of the cosmic microwave background temperature at 1.47 GHz  

SciTech Connect (OSTI)

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

59

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

60

MADmap: A Massively Parallel Maximum-Likelihood Cosmic Microwave Background Map-Maker  

SciTech Connect (OSTI)

MADmap is a software application used to produce maximum-likelihood images of the sky from time-ordered data which include correlated noise, such as those gathered by Cosmic Microwave Background (CMB) experiments. It works efficiently on platforms ranging from small workstations to the most massively parallel supercomputers. Map-making is a critical step in the analysis of all CMB data sets, and the maximum-likelihood approach is the most accurate and widely applicable algorithm; however, it is a computationally challenging task. This challenge will only increase with the next generation of ground-based, balloon-borne and satellite CMB polarization experiments. The faintness of the B-mode signal that these experiments seek to measure requires them to gather enormous data sets. MADmap is already being run on up to O(1011) time samples, O(108) pixels and O(104) cores, with ongoing work to scale to the next generation of data sets and supercomputers. We describe MADmap's algorithm based around a preconditioned conjugate gradient solver, fast Fourier transforms and sparse matrix operations. We highlight MADmap's ability to address problems typically encountered in the analysis of realistic CMB data sets and describe its application to simulations of the Planck and EBEX experiments. The massively parallel and distributed implementation is detailed and scaling complexities are given for the resources required. MADmap is capable of analysing the largest data sets now being collected on computing resources currently available, and we argue that, given Moore's Law, MADmap will be capable of reducing the most massive projected data sets.

Cantalupo, Christopher; Borrill, Julian; Jaffe, Andrew; Kisner, Theodore; Stompor, Radoslaw

2009-06-09T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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.


61

SYSTEMATIC EFFECTS IN INTERFEROMETRIC OBSERVATIONS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION  

SciTech Connect (OSTI)

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

62

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

63

Cosmic microwave background constraints on dark energy dynamics: analysis beyond the power spectrum  

E-Print Network [OSTI]

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis based on the CMB bispectrum. By considering the three multipoles as independent variables, we reveal a complex structure of peaks and valleys determined by the re-projection of the primordial acoustic oscillations through the lensing mechanism. We study the dependence of this system on the expansion rate at the epoch in which the weak lensing power injection is relevant, probing the dark energy equation of state at redshift corresponding to the equivalence with matter or higher ($w_\\infty$). We evaluate the impact of the bispectrum observable on the CMB capability of constraining the dark energy dynamics. We perform a maximum likelihood analysis by varying the dark energy abundance, the present equation of state $w_0$ and $w_\\infty$. We show that the projection degeneracy affecting a pure power spectrum analysis in total intensity is broken if the bispectrum is taken into account. For a Planck-like experiment, assuming nominal performance, no foregrounds or systematics, and fixing all the parameters except $w_0$, $w_\\infty$ and the dark energy abundance, a percent and ten percent precision measure of $w_0$ and $w_\\infty$ is achievable from CMB data only. These results indicate that the detection of the weak lensing signal by the forthcoming CMB probes may be relevant to gain insight into the dark energy dynamics at the onset of cosmic acceleration.

Fabio Giovi; Carlo Baccigalupi; Francesca Perrotta

2005-05-18T23:59:59.000Z

64

Harmonic polynomials for expanding the fluctuations of the Cosmic Microwave Background: The Poincare and the 3-sphere model  

E-Print Network [OSTI]

Fluctuations of the Cosmic Microwave Background CMB are observed by the WMAP. When expanded into the harmonic eigenmodes of the space part of a cosmological model, they provide insight into the large-scale topology of space. All harmonic polynomials on the multiply connected dodecahedral Poincare space are constructed. Strong and specific selection rules are given by comparing the polynomials to those on the 3-sphere, its simply connected cover.

Peter Kramer

2007-01-01T23:59:59.000Z

65

SECOND SEASON QUIET OBSERVATIONS: MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRUM AT 95 GHz  

SciTech Connect (OSTI)

The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95 GHz. The 43 GHz results have been published in a previous paper, and here we report the measurement of CMB polarization power spectra using the 95 GHz data. This data set comprises 5337 hr of observations recorded by an array of 84 polarized coherent receivers with a total array sensitivity of 87 {mu}K{radical}s. Four low-foreground fields were observed, covering a total of {approx}1000 deg{sup 2} with an effective angular resolution of 12.'8, allowing for constraints on primordial gravitational waves and high signal-to-noise measurements of the E-modes across three acoustic peaks. The data reduction was performed using two independent analysis pipelines, one based on a pseudo-C {sub l} (PCL) cross-correlation approach, and the other on a maximum-likelihood (ML) approach. All data selection criteria and filters were modified until a predefined set of null tests had been satisfied before inspecting any non-null power spectrum. The results derived by the two pipelines are in good agreement. We characterize the EE, EB, and BB power spectra between l = 25 and 975 and find that the EE spectrum is consistent with {Lambda}CDM, while the BB power spectrum is consistent with zero. Based on these measurements, we constrain the tensor-to-scalar ratio to r = 1.1{sup +0.9} {sub -0.8} (r < 2.8 at 95% C.L.) as derived by the ML pipeline, and r = 1.2{sup +0.9} {sub -0.8} (r < 2.7 at 95% C.L.) as derived by the PCL pipeline. In one of the fields, we find a correlation with the dust component of the Planck Sky Model, though the corresponding excess power is small compared to statistical errors. Finally, we derive limits on all known systematic errors, and demonstrate that these correspond to a tensor-to-scalar ratio smaller than r = 0.01, the lowest level yet reported in the literature.

Araujo, D.; Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States); Chinone, Y. [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K.; Reeves, R. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 E. California Blvd M/C 249-17, Pasadena, CA 91125 (United States); Monsalve, R.; Bustos, R. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Naess, S. K.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Wehus, I. K. [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Bronfman, L. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Church, S. E. [Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Varian Physics Building, 382 Via Pueblo Mall, Stanford, CA 94305 (United States); Dickinson, C. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Gaier, T., E-mail: ibuder@uchicago.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Collaboration: QUIET Collaboration; and others

2012-12-01T23:59:59.000Z

66

Background  

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

Background 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...

67

Microwave influence on the isolated heart function. 2: Combined effect of radiation and some drugs  

SciTech Connect (OSTI)

The combined effects of microwave radiation and some drugs were studied in an isolated frog auricle preparation. The experiments established that exposure to pulse-modulated 915 Mhz microwaves for up to 40 min had no effect on either the rate or the amplitude of spontaneous auricle twitches, unless the average absorbed power was high enough to produce preparation heating. Treatment of the preparation with saline containing (0.6--3.0) 10{sup {minus}5} M of propranolol or (0.5--1.5) 10{sup {minus}7} M of atropine altered neither its pacemaker nor its contractile functions; these drugs also had no effect when they were combined with nonthermal microwave irradiation. Caffeine (1 mM) strongly increased the average heart power, which was calculated as the product of twitch rate ad amplitude. The caffeine effect appeared to be significantly augmented (by about 15%, P<0.02) under exposure to burst-type pulsed microwaves (pulse width, 1.5 msec; pause, 2.5 msec; 8 pulses/burst, 16 bursts/s; average SAR, 8--10 W/kg). By itself, this modulation was not effective; the heating of the preparation and saline during exposure was approximately 0.1 C, which could not account for the detected changes. The experimental results demonstrate that caffeine treatment increases the microwave sensitivity of the frog auricle preparation and reveals primarily subthreshold, nonthermal microwave effect.

Pakhomov, A.G.; Dubovick, B.V.; Degtyariov, I.G.; Pronkevich, A.N. [Russian Academy of Medical Sciences, Obninsk (Russian Federation). Medical Radiology research Center

1995-09-01T23:59:59.000Z

68

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

69

Method for digesting spent ion exchange resins and recovering actinides therefrom using microwave radiation  

DOE Patents [OSTI]

The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.

Maxwell, III, Sherrod L. (Aiken, SC); Nichols, Sheldon T. (Augusta, GA)

1999-01-01T23:59:59.000Z

70

BACKGROUND  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program CumulusA t i o n dataWhatNationalBACKGROUND The safe

71

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

SciTech Connect (OSTI)

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

72

THE HIGH BACKGROUND RADIATION AREA IN RAMSAR IRAN: GEOLOGY, NORM, BIOLOGY, LNT, AND POSSIBLE REGULATORY FUN  

SciTech Connect (OSTI)

The city of Ramsar Iran hosts some of the highest natural radiation levels on earth, and over 2000 people are exposed to radiation doses ranging from 1 to 26 rem per year. Curiously, inhabitants of this region seem to have no greater incidence of cancer than those in neighboring areas of normal background radiation levels, and preliminary studies suggest their blood cells experience fewer induced chromosomal abnormalities when exposed to 150 rem ''challenge'' doses of radiation than do the blood cells of their neighbors. This paper will briefly describe the unique geology that gives Ramsar its extraordinarily high background radiation levels. It will then summarize the studies performed to date and will conclude by suggesting ways to incorporate these findings (if they are borne out by further testing) into future radiation protection standards.

Karam, P. A.

2002-02-25T23:59:59.000Z

73

Thermal and non-thermal radiation of rotating polarizable particle moving in an equilibrium background of electromagnetic radiation  

E-Print Network [OSTI]

A theory of thermal and nonthermal radiation in a vacuum background of arbitrary temperature generated by relativistic polarizable particle with spin is proposed. When the particle rotates, radiation is produced by vacuum fluctuations even in the case of zero temperature of the system. In the ultrarelativistic case, the spectral-angular intensity of radiation is concentrated along the velocity of the particle. At finite temperatures of particle and vacuum, the particle temperature (in its rest frame) rather quickly acquires an equilibrium magnitude depending on the velocities of rotation and uniform motion and the background temperature. This equilibrium temperature determines the intensity of radiation. The dynamical slowing down takes a very long time until the kinetic energy of uniform motion and rotation is converted into radiation.

A. A. Kyasov; G. V Dedkov

2014-09-17T23:59:59.000Z

74

Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve ? (?mv) = 16 meV and ? (Neff)(Neff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero ?m??m?, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics — the origin of mass. This precise a measurement of Neff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that Neff = 3.046.

Slosar, A.; Arnold, K.; Austermann, J.; Benson, B. A.; Bischoff, C.; Bock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; Carvalho, C. S.; Chang, C. L.; Chiang, H. C.; Church, S.; Cooray, A.; Crawford, T. M.; Dawson, K. S.; Das, S.; Devlin, M. J.; Dobbs, M.; Dodelson, S.; Dore, O.; Dunkley, J.; Errard, J.; Fraisse, A.; Gallicchio, J.; Halverson, N. W.; Hanany, S.; Hildebrandt, S. R.; Hincks, A.; Hlozek, R.; Holder, G.; Holzapfel, W. L.; Honscheid, K.; Hu, W.; Hubmayr, J.; Irwin, K.; Jones, W. C.; Kamionkowski, M.; Keating, B.; Keisler, R.; Knox, L.; Komatsu, E.; Kovac, J.; Lawrence, C.; Lee, A. T.; Leitch, E.; Linder, E.; Lubin, P.; McMahon, J.; Miller, A.; Newburgh, L.; Niemack, M. D.; Nguyen, H.; Nguyen, H. T.; Page, L.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Sehgal, N.; Seljak, U.; Sievers, J.; Silverstein, E.; Smith, K. M.; Spergel, D.; Staggs, S. T.; Stark, A.; Stompor, R.; Vieregg, A. G.; Wang, G.; Watson, S.; Wollack, E. J.; Wu, W. L.K.; Yoon, K. W.; Zahn, O.; Kuo, C. -L.

2015-03-01T23:59:59.000Z

75

Experimental study of variations in background radiation and the effect on Nuclear Car Wash sensitivity  

SciTech Connect (OSTI)

Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate, including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash.

Church, J; Slaughter, D; Norman, E; Asztalos, S; Biltoft, P

2007-02-07T23:59:59.000Z

76

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

SciTech Connect (OSTI)

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

77

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

SciTech Connect (OSTI)

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

78

Developing a Methodology for Characterizing the Effects of Building Materials’ Natural Radiation Background on a Radiation Portal Monitoring System  

E-Print Network [OSTI]

, weather, and time of day. 6 Gamma rays are electromagnetic radiation emitted by excited nuclei in order for them to reach the ground state after decaying. Once emitted, these particles mainly interact with matter in three ways: photoelectric effect... and measured density were then used to define the MCNP material card for concrete. Pulse height tallies were used to determine the total gamma ray count rate in each of the four gamma detectors in the RPM. 5 CHAPTER II BACKGROUND II.A. Radiation...

Fitzmaurice, Matthew Blake 1988-

2012-11-06T23:59:59.000Z

79

Integrated Molecular Analysis Indicates Undetectable Change in DNA Damage in Mice after Continuous Irradiation at ~ 400-fold Natural Background Radiation  

E-Print Network [OSTI]

Background: In the event of a nuclear accident, people are exposed to elevated levels of continuous low dose-rate radiation. Nevertheless, most of the literature describes the biological effects of acute radiation.

Olipitz, Werner

80

FIRST SEASON QUIET OBSERVATIONS: MEASUREMENTS OF COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRA AT 43 GHz IN THE MULTIPOLE RANGE 25 {<=} l {<=} 475  

SciTech Connect (OSTI)

The Q/U Imaging ExperimenT (QUIET) employs coherent receivers at 43 GHz and 94 GHz, operating on the Chajnantor plateau in the Atacama Desert in Chile, to measure the anisotropy in the polarization of the cosmic microwave background (CMB). QUIET primarily targets the B modes from primordial gravitational waves. The combination of these frequencies gives sensitivity to foreground contributions from diffuse Galactic synchrotron radiation. Between 2008 October and 2010 December, over 10,000 hr of data were collected, first with the 19 element 43 GHz array (3458 hr) and then with the 90 element 94 GHz array. Each array observes the same four fields, selected for low foregrounds, together covering Almost-Equal-To 1000 deg{sup 2}. This paper reports initial results from the 43 GHz receiver, which has an array sensitivity to CMB fluctuations of 69 {mu}K{radical}s. The data were extensively studied with a large suite of null tests before the power spectra, determined with two independent pipelines, were examined. Analysis choices, including data selection, were modified until the null tests passed. Cross-correlating maps with different telescope pointings is used to eliminate a bias. This paper reports the EE, BB, and EB power spectra in the multipole range l = 25-475. With the exception of the lowest multipole bin for one of the fields, where a polarized foreground, consistent with Galactic synchrotron radiation, is detected with 3{sigma} significance, the E-mode spectrum is consistent with the {Lambda}CDM model, confirming the only previous detection of the first acoustic peak. The B-mode spectrum is consistent with zero, leading to a measurement of the tensor-to-scalar ratio of r = 0.35{sup +1.06}{sub -0.87}. The combination of a new time-stream 'double-demodulation' technique, side-fed Dragonian optics, natural sky rotation, and frequent boresight rotation leads to the lowest level of systematic contamination in the B-mode power so far reported, below the level of r = 0.1.

Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.; Smith, K. M. [Kavli Institute for Cosmological Physics, Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Chinone, Y. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Cleary, K.; Reeves, R. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dumoulin, R. N.; Newburgh, L. B.; Zwart, J. T. L. [Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Monsalve, R.; Bustos, R. [Department of Physics, University of Miami, Coral Gables, FL 33146 (United States); Naess, S. K.; Eriksen, H. K. [Institute of Theoretical Astrophysics, University of Oslo, N-0315 Oslo (Norway); Wehus, I. K. [Department of Physics, University of Oslo, N-0316 Oslo (Norway); Zuntz, J. A. [Department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Bronfman, L. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Church, S. E. [Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University, Varian Physics Building, Stanford, CA 94305 (United States); Dickinson, C., E-mail: akito@kicp.uchicago.edu [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-11-10T23:59:59.000Z

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81

A New Upper Limit on the Large Angular Scale Polarization of the Cosmic Microwave Background Radiation  

E-Print Network [OSTI]

, dark matter, and dark energy to the overall energy density of the universe. In addition to being of a new breed of highly-sensitive instruments that will one day map out this interesting property knowledge, Brian Keat- ing, also deserves much credit. Thanks to him I have finally memorized the radiometer

Timbie, Peter

82

Spherical Shell Cosmological Model and Uniformity of Cosmic Microwave Background Radiation  

E-Print Network [OSTI]

Considered is spherical shell as a model for visible universe and parameters that such model must have to comply with the observable data. The topology of the model requires that motion of all galaxies and light must be confined inside a spherical shell. Consequently the observable universe cannot be defined as a sphere centered on the observer, rather it is an arc length within the volume of the spherical shell. The radius of the shell is 4.46 $\\pm$ 0.06 Gpc, which is for factor $\\pi$ smaller than radius of a corresponding 3-sphere. However the event horizon, defined as the arc length inside the shell, has the size of 14.0 $\\pm$ 0.2 Gpc, which is in agreement with the observable data. The model predicts, without inflation theory, the isotropy and uniformity of the CMB. It predicts the correct value for the Hubble constant $H_0$ = 67.26 $\\pm$ 0.90 km/s/Mpc, the cosmic expansion rate $H(z)$, and the speed of the event horizon in agreement with observations. The theoretical suport for shell model comes from general relativity, curvature of space by mass, and from holographic principle. The model explains the reason for the established discrepancy between the non-covariant version of the holographic principle and the calculated dimensionless entropy $(S/k)$ for the visible universe, which exceeds the entropy of a black hole. The model is in accordance with the distribution of radio sources in space, type Ia data, and data from the Hubble Ultra Deep Field optical and near-infrared survey.

Branislav Vlahovic

2012-07-06T23:59:59.000Z

83

A Shallow Underground Laboratory for Low-Background Radiation Measurements and Materials Development  

SciTech Connect (OSTI)

Abstract: Pacific Northwest National Laboratory recently commissioned a new shallow underground laboratory, located at a depth of approximately 30 meters water-equivalent. This new addition to the small class of radiation measurement laboratories located at modest underground depths worldwide houses the latest generation of custom-made, high-efficiency, low-background gamma-ray spectrometers and gas proportional counters. This manuscript describes the unique capabilities present in the shallow underground laboratory; these include large-scale ultra-pure materials production and a suite of radiation detection systems. Reported data characterize the degree of background reduction achieved through a combination of underground location, graded shielding, and rejection of cosmic-ray events. We conclude by presenting measurement targets and future opportunities.

Aalseth, Craig E.; Bonicalzi, Ricco; Cantaloub, Michael G.; Day, Anthony R.; Erikson, Luke E.; Fast, James E.; Forrester, Joel B.; Fuller, Erin S.; Glasgow, Brian D.; Greenwood, Lawrence R.; Hoppe, Eric W.; Hossbach, Todd W.; Hyronimus, Brian J.; Keillor, Martin E.; Mace, Emily K.; McIntyre, Justin I.; Merriman, Jason H.; Myers, Allan W.; Overman, Cory T.; Overman, Nicole R.; Panisko, Mark E.; Seifert, Allen; Warren, Glen A.; Runkle, Robert C.

2012-11-08T23:59:59.000Z

84

Influence of Spinning Electric Fields on Natural Background Gamma-Radiation  

E-Print Network [OSTI]

This paper considers influence of spinning electric field on statistics of natural background gamma-radiation. The spinning electric field, shown as a virtual gyroscope, has quantum mechanics characteristics. Interaction of the virtual fermion-like gyroscope with bosons (gamma-quanta) results in lowering intensity of the gamma-radiation and altering Poisson distribution. The statistic of the observed phenomenon depends on the direction of rotation of the virtual gyroscope. The results are discussed in a shade of spin-spin interaction having regard to realizing thermodynamically profitable conditions. Similarity of observed reduction of gamma-radiation in spinning electric fields and that for mechanical rotation stresses a special role of rotation itself, disregarding the matter of its carrier.

Mark Krinker; Felix Kitaichik

2010-04-28T23:59:59.000Z

85

The Microwave Air Yield Beam Experiment (MAYBE): measurement of GHz radiation for Ultra-High Energy Cosmic Rays detection  

E-Print Network [OSTI]

We present first measurements by MAYBE of microwave emission from an electron beam induced air plasma, performed at the electron Van de Graaff facility of the Argonne National Laboratory. Coherent radio Cherenkov, a major background in a previous beam experiment, is not produced by the 3 MeV beam, which simplifies the interpretation of the data. Radio emission is studied over a wide range of frequencies between 3 and 12 GHz. This measurement provides further insight on microwave emission from extensive air showers as a novel detection technique for Ultra-High Energy Cosmic Rays.

M. Monasor; M. Bohacova; C. Bonifazi; G. Cataldi; S. Chemerisov; J. R. T. De Mello Neto; P. Facal San Luis; B. Fox; P. W. Gorham; C. Hojvat; N. Hollon; R. Meyhandan; L. C. Reyes; B. Rouille D'Orfeuil; E. M. Santos; J. Pochez; P. Privitera; H. Spinka; V. Verzi; C. Williams; J. Zhou

2011-08-31T23:59:59.000Z

86

Massive charged scalar field in the Kerr-Newman background II: Hawking radiation  

E-Print Network [OSTI]

We perform accurate calculations of the energy-, momentum-, and charge-emission rates of a charged scalar field in the background of the Kerr-Newman black hole at the range of parameters for which the effect is not negligibly small and, at the same time, the semiclassical regime is, at least marginally, valid. For black holes with charge below or not much higher than the charge accretion limit $Q \\sim \\mu M/e$ (where $e$ and $\\mu$ are the electron's mass and charge), the time between the consequent emitting of two charged particles is very large. For primordial black holes the transition between the increasing and decreasing of the ratio $Q/M$ occurs around the charge accretion limit. The rotation increases the intensity of radiation up to three orders, while the effect of the field's mass strongly suppresses the radiation.

R. A. Konoplya; A. Zhidenko

2014-04-03T23:59:59.000Z

87

Apparatus having reduced background for measuring radiation activity in aerosol particles  

DOE Patents [OSTI]

Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.

Rodgers, John C. (Santa Fe, NM); McFarland, Andrew R. (College Station, TX); Oritz, Carlos A. (Bryan, TX); Marlow, William H. (College Station, TX)

1992-01-01T23:59:59.000Z

88

Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures  

SciTech Connect (OSTI)

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-off, 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 continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.

Alarcon, Ricardo [Arizona State University, Glendale, AZ (United States); Balascuta, S. [Arizona State University, Glendale, AZ (United States); Benson, Stephen V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Bertozzi, William [Massachusetts Institute of Technology, Cambridge, MA (United States); Boyce, James R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cowan, Ray [Massachusetts Institute of Technology, Cambridge, MA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Evtushenko, Pavel [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Fisher, P. [Massachusetts Institute of Technology, Cambridge, MA (United States); Ihloff, Ernest E. [Hampton University, Hampton, VA (United States); Kalantarians, Narbe [Hampton University, Hampton, VA (United States); Kelleher, Aidan Michael [Massachusetts Institute of Technology, Cambridge, MA (United States); Krossler, W. J. [William and Mary College, Williamsburg, VA (United States); Legg, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Long, Elena [University of New Hampshire, Durham, NH (United States); Milner, Richard [Massachusetts Institute of Technology, Cambridge, MA (United States); Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Ou, Longwu [Massachusetts Institute of Technology, Cambridge, MA (United States); Schmookler, Barack Abraham [Massachusetts Institute of Technology, Cambridge, MA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tschalar, C. [Massachusetts Institute of Technology, Cambridge, MA (United States); Williams, Gwyn P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2013-11-01T23:59:59.000Z

89

State background-radiation levels: results of measurements taken during 1975-1979  

SciTech Connect (OSTI)

Background radiation levels across the United States have been measured by the Off-Site Pollutant Measurements Group of the Health and Safety Research Division at Oak Ridge National Laboratory (ORNL). These measurements have been conducted as part of the ORNL program of radiological surveillance at inactive uranium mills and sites formerly utilized during Manhattan Engineer District and early Atomic Energy Commission projects. The measurements included determination of /sup 226/Ra, /sup 232/Th, and /sup 238/U concentrations in surface soil samples and measurement of external gamma-ray exposure rates at 1 m above the ground surface at the location of soil sampling. This information is being utilized for comparative purposes to determine the extent of contamination present at the survey sites and surrounding off-site areas. The sampling program to date has provided background information at 356 locations in 33 states. External gamma-ray exposure rates were found to range from less than 1 to 34 ..mu..R/h, with an US average of 8.5 ..mu..R/h. The nationwide average concentrations of /sup 226/Ra, /sup 232/Th, and /sup 238/U in surface soil were determined to be 1.1, 0.98, and 1.0 pCi/g, respectively.

Myrick, T.E.; Berven, B.A.; Haywood, F.F.

1981-11-01T23:59:59.000Z

90

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

91

Determining the Impact of Concrete Roadways on Gamma Ray Background Readings for Radiation Portal Monitoring Systems  

E-Print Network [OSTI]

country of origin. To combat the threat of nuclear trafficking, radiation portal monitors (RPMs) are deployed around the world to intercept illicit material while in transit by passively detecting gamma and neutron radiation. Portal monitors in some...

Ryan, Christopher Michael

2012-07-16T23:59:59.000Z

92

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

93

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

94

Microwave Absorption and Radiation from Large-area Multilayer CVD Graphene  

E-Print Network [OSTI]

2009;9(1):422–6. [32] Schwierz F. Graphene transistors. Nat Nano 2010;5(7):487–96. [33] Dragoman M, Neculoiu D, Dragoman D, Deligeorgis G, Konstantinidis G, Cismaru A, et al. Graphene for microwaves. IEEE Microw Mag 2010;11(7):81–6. [34] Fallahi A... graphene were mea- sured at 457 nm (2.71 eV), 532 nm (2.33 eV) and 633 nm (1.96 eV) (see Fig. S1a–d). The DC resistivity was measured using a four-point probe contact stylus. The Keithley Model 2100/120 Digital Multimeter with a four-point probe...

Wu, Bian; Tuncer, Hatice M.; Katsounaros, Anestis; Wu, Weiping; Cole, Matthew T.; Ying, Kai; Zhang, Lianhong; Milne, William I.; Hao, Yang

95

Simulation of Radiation Backgrounds associated with the HEXRI Diagnostics at the National Ignition Facility  

SciTech Connect (OSTI)

Experiments resulting in a significant neutron yield are scheduled to start in 2010 at the National Ignition Facility (NIF). A wide range of diagnostics will be used to measure several parameters of implosion such as the core and fuel shape, temperatures and densities, and neutron yield. Accurate evaluations of the neutron and gamma backgrounds are important for several diagnostics, such as the High Energy X-ray Imager (HEXRI). Several Monte-Carlo simulations were performed to identify the expected signal to background ratios at several potential locations for the HEXRI diagnostics. Gamma backgrounds were significantly reduced by using tungsten collimators. The collimators resulted in the reduction of the gamma background at the HEXRI scintillators by more than an order of magnitude during the first 40 ns following a THD shot.

Khater, H; Dauffy, L; Tommasini, R; Eckart, M; Eder, D

2009-10-05T23:59:59.000Z

96

SIMULATION OF RADIATION BACKGROUNDS ASSOCIATED WITH NUCLEAR DIAGNOSTICS IN THE NATIONAL IGNITION FACILITY  

SciTech Connect (OSTI)

Experiments resulting in a significant neutron yield are scheduled to start in 2010 at the National Ignition Facility (NIF). Several experiments utilizing Tritium-Hydrogen-Deuterium (THD) and Deuterium-Tritium (DT) targets are scheduled as part of the National Ignition Campaign (NIC). A wide range of diagnostics will be used to measure several parameters of implosion such as the core and fuel shape, temperatures and densities, and neutron yield. Accurate evaluations of the neutron and gamma backgrounds are important for several diagnostics, such as the High Energy X-ray Imager (HEXRI) and Neutron-Time-Of-Flight (nTOF). Several sources of neutron and gamma backgrounds will impact the accuracy of the diagnostics measurements. Fusion neutrons generated by fuel burn and secondary neutrons resulting from the fusion neutrons interaction with structures present inside and outside the Target Chamber (TC) contribute to the neutron background. In the meantime, X-rays emitted from the implosion, X-rays resulting from Laser Plasma Interaction (LPI) of NIF beams with the hohlraum, and gamma-rays induced by neutron interactions with different structures inside and outside the TC contribute to the gamma background. A detailed model has been developed of the NIF facility and all structures inside the TC. Several Monte-Carlo simulations were performed to identify the expected signal-to- background ratios at several potential locations for the HEXRI and nTOF diagnostics. Gamma backgrounds associated with HEXRI were significantly reduced by using a tungsten collimator. The collimator resulted in the reduction of the gamma background at the HEXRI scintillator by more than an order of magnitude during the first 40 ns following a THD shot. The nTOF20 detectors inside the Neutron Spectrometry room are exposed to low levels of neutron and gamma background during yield shots.

Khater, H; Dauffy, L; Tommasini, R; Eckart, M; Eder, D

2009-08-19T23:59:59.000Z

97

Systems and methods for detecting nuclear radiation in the presence of backgrounds  

DOE Patents [OSTI]

Systems and methods for the simultaneous detection and identification of radiation species, including neutrons, gammas/x-rays and minimum ionizing particles (MIPs). A plurality of rectangular and/or triangularly shaped radiation sensitive scintillators can be configured from a plurality of nano-sized particles, dopants and an extruded plastic material. A wavelength-shifting fiber can then be located within a central hole of each extruded scintillator, wherein the wavelength-shifting fiber absorbs scintillation light and re-emits the light at a longer wavelength, thereby piping the light to a photodetector whose response to the light indicates the presence of radiation The resulting method and system can simultaneously detect neutrons, gamma rays, x-rays and cosmic rays (MIPs) and identify each.

Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

2005-06-21T23:59:59.000Z

98

Mass without radiation: heavily obscured AGN, the X-ray Background and the Black Hole Mass Density  

E-Print Network [OSTI]

A recent revision of black hole scaling relations (Kormendy & Ho 2013), indicates that the local mass density in black holes should be increased by up to a factor of five with respect to previously determined values. The local black hole mass density is connected to the mean radiative efficiency of accretion through the time integral of the AGN volume density and a significant increase of the local black holes mass density would have interesting consequences on AGN accretion properties and demography. One possibility to explain a large black hole mass density is that most of the Black Hole growth is via radiatively inefficient channels such as super Eddington accretion, however, given the intrinsic degeneracies in the Soltan argument, this solution is not unique. Here we show how it is possible to accommodate a larger fraction of heavily buried, Compton thick AGN, without violating the limit imposed by the hard X-ray and mid-infrared backgrounds spectral energy density.

Comastri, A; Marconi, A; Risaliti, G; Salvati, M

2015-01-01T23:59:59.000Z

99

Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies  

E-Print Network [OSTI]

The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

Sailer, André; Lohse, Thomas

2013-01-10T23:59:59.000Z

100

Reduction of Radioactive Backgrounds in Electroformed Copper for Ultra-Sensitive Radiation Detectors  

SciTech Connect (OSTI)

Abstract Ultra-pure construction materials are required for the next generation of neutrino physics, dark matter and environmental science applications. These new efforts require materials with purity levels at or below 1 uBq/kg 232Th and 238U. Yet radiometric analysis lacks sensitivity below ~10 uBq/kg for the U and Th decay chains. This limits both the selection of clean materials and the validation of purification processes. Copper is an important high-purity material for low-background experiments due to the ease with which it can be purified by electrochemical methods. Electroplating for purification into near-final shapes, known as electroforming, is one such method. Continued refinement of the copper electroforming process is underway, for the first time guided by an ICP-MS based assay method that can measure 232Th and 238U near the desired purity levels. An assay of electroformed copper at 10 uBq/kg for 232Th has been achieved and is described. The implications of electroformed copper at or better than this purity on next-generation low-background experiments are discussed.

Hoppe, Eric W.; Aalseth, Craig E.; Farmer, Orville T.; Hossbach, Todd W.; Liezers, Martin; Miley, Harry S.; Overman, Nicole R.; Reeves, James H.

2014-02-08T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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.
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to obtain the most current and comprehensive results.


101

Background Radiation Survey of the Radiological/Nuclear Countermeasures Test and Evaluation Center  

SciTech Connect (OSTI)

In preparation for operations at the Radiological/Nuclear Countermeasures Test and Evaluation Complex (Rad/NucCTEC), the Department of Homeland Security Domestic Nuclear Detection Office (DHS/DNDO) requested that personnel from the Remote Sensing Laboratory (RSL) conduct a survey of the present radiological conditions at the facility. The measurements consist of the exposure rate from a high-pressure ion chamber (HPIC), high-resolution spectra from a high-purity germanium (HPGe) system in an in situ configuration, and low-resolution spectra from a sodium iodide (NaI) detector in a radiation detection backpack. Measurements with these systems were collected at discrete locations within the facility. Measurements were also collected by carrying the VECTOR backpack throughout the complex to generate a map of the entire area. The area was also to be surveyed with the Kiwi (an array of eight-2-inch x 4-inch x 16-inch NaI detectors) from the Aerial Measuring Systems; however, conflicts with test preparation activities at the site prevented this from being accomplished.

Colin Okada

2010-09-16T23:59:59.000Z

102

Unsterile-active neutrino mixing: Consequences on radiative decay and bounds from the x-ray background  

SciTech Connect (OSTI)

We consider a sterile neutrino to be an unparticle, namely, an unsterile neutrino, with anomalous dimension {eta} and study its mixing with a canonical active neutrino via a seesaw mass matrix. We show that there is no unitary transformation that diagonalizes the mixed propagator and a field redefinition is required. The propagating or 'mass' states correspond to an unsterilelike and activelike mode. The unsterile mode features a complex pole or resonance for 0{<=}{eta}<1/3 with an 'invisible width' which is the result of the decay of the unsterile mode into the active mode and the massless particles of the hidden conformal sector. For {eta}{>=}1/3, the complex pole disappears, merging with the unparticle threshold. The active mode is described by a stable pole, but 'inherits' a nonvanishing spectral density above the unparticle threshold as a consequence of the mixing. We find that the radiative decay width of the unsterile neutrino into the active neutrino (and a photon) via charged current loops, is suppressed by a factor {approx}[2sin{sup 2}({theta}{sub 0})(M{sup 2}/{lambda}{sup 2})]{sup {eta}}{sup /(1-{eta})}, where {theta}{sub 0} is the mixing angle for {eta}=0, M is approximately the mass of the unsterile neutrino, and {lambda}>>M is the unparticle scale. The suppression of the radiative (visible) decay width of the sterile neutrino weakens the bound on the mass and mixing angle from the x-ray or soft gamma-ray background.

Boyanovsky, D. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Holman, R.; Hutasoit, Jimmy A. [Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2009-07-15T23:59:59.000Z

103

Impact of Hillslope-Scale Organization of Topography, Soil Moisture, Soil Temperature, and Vegetation on Modeling Surface Microwave Radiation Emission  

E-Print Network [OSTI]

Microwave radiometry will emerge as an important tool for global remote sensing of near-surface soil moisture in the coming decade. In this modeling study, we find that hillslope-scale topography (tens of meters) influences ...

Flores, Alejandro N.

104

High power microwave generator  

DOE Patents [OSTI]

A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

Ekdahl, C.A.

1983-12-29T23:59:59.000Z

105

Cosmological origin of anomalous radio background  

SciTech Connect (OSTI)

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

106

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

107

Entanglement from thermal black body radiation  

E-Print Network [OSTI]

Two non--interacting quantum systems which couple to a common environment with many degrees of freedom initially in thermal equilibrium can become entangled due to the indirect interaction mediated through this heat bath. I examine here the dynamics of reservoir induced entanglement for a heat bath consisting of a thermal electro--magnetic radiation field, such as black body radiation or the cosmic microwave background, and show how the effect can be understood as result of an effective induced interaction.

Daniel Braun

2005-09-06T23:59:59.000Z

108

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

109

Blazar Duty-Cycle at gamma-ray Frequecies: Constraints from Extragalactic Background Radiation and Prospects for AGILE and GLAST  

E-Print Network [OSTI]

We take into account the constraints from the observed extragalactic gamma-ray background to estimate the maximum duty cycle allowed for a selected sample of WMAP Blazars, in order to be detectable by AGILE and GLAST gamma-ray experiments. For the nominal sensitivity values of both instruments, we identify a subset of sources which can in principle be detectable also in a steady state without over-predicting the extragalactic background. This work is based on the results of a recently derived Blazar radio LogN-LogS obtained by combining several multi-frequency surveys.

Pittori, Carlotta; Colafrancesco, Sergio; Giommi, Paolo

2007-01-01T23:59:59.000Z

110

Blazar Duty-Cycle at gamma-ray Frequecies: Constraints from Extragalactic Background Radiation and Prospects for AGILE and GLAST  

E-Print Network [OSTI]

We take into account the constraints from the observed extragalactic gamma-ray background to estimate the maximum duty cycle allowed for a selected sample of WMAP Blazars, in order to be detectable by AGILE and GLAST gamma-ray experiments. For the nominal sensitivity values of both instruments, we identify a subset of sources which can in principle be detectable also in a steady state without over-predicting the extragalactic background. This work is based on the results of a recently derived Blazar radio LogN-LogS obtained by combining several multi-frequency surveys.

Carlotta Pittori; Elisabetta Cavazzuti; Sergio Colafrancesco; Paolo Giommi

2007-05-04T23:59:59.000Z

111

Microwave detector  

DOE Patents [OSTI]

A microwave detector (10) is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite (26, 28) produces a magnetization field flux that links a B-dot loop (16, 20). The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means (18, 22) are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

Meldner, Heiner W. (Moss Beach, CA); Cusson, Ronald Y. (Chapel Hill, NC); Johnson, Ray M. (San Ramon, CA)

1986-01-01T23:59:59.000Z

112

Microwave detector  

DOE Patents [OSTI]

A microwave detector is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite produces a magnetization field flux that links a B-dot loop. The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

1985-02-08T23:59:59.000Z

113

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

114

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

115

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

116

Cosmic Microwave Background Project at NERSC  

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

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117

Anomalous Microwave Emission  

E-Print Network [OSTI]

Improved knowledge of diffuse Galactic emission is important to maximize the scientific return from scheduled CMB anisotropy missions. Cross-correlation of microwave maps with maps of the far-IR dust continuum show a ubiquitous microwave emission component whose spatial distribution is traced by far-IR dust emission. The spectral index of this emission, beta_{radio} = -2.2 (+0.5 -0.7) is suggestive of free-free emission but does not preclude other candidates. Comparison of H-alpha and microwave results show that both data sets have positive correlations with the far-IR dust emission. Microwave data, however, are consistently brighter than can be explained solely from free-free emission traced by H-alpha. This ``anomalous'' microwave emission can be explained as electric dipole radiation from small spinning dust grains. The anomalous component at 53 GHz is 2.5 times as bright as the free-free emission traced by H-alpha, providing an approximate normalization for models with significant spinning dust emission.

A. Kogut

1999-02-22T23:59:59.000Z

118

New Limits to the IR Background: Bounds on Radiative Neutrino Decay and on VMO Contributions to the Dark Matter Problem  

E-Print Network [OSTI]

From considering the effect of gamma-gamma interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared (IR) photons which are robust and essentially model-independent. The resulting limits are up to two orders of magnitude more restrictive than direct observations in the 0.025-0.3eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05eV and on Very Massive Objects (VMOs) as providing the dark matter needed to explain galaxy rotation curves.

S. D. Biller; J. Buckley; A. Burdett; J. Bussons Gordo; D. A. Carter-Lewis; D. J. Fegan; J. Findley; J. A. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; R. Lessard; J. E. McEnery; G. Mohanty; J. Quinn; A. J. Rodgers; H. J. Rose; F. Samuelson; G. Sembroski; P. Skelton; T. C. Weekes; J; Zweerink

1998-02-18T23:59:59.000Z

119

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

120

Method and apparatus for thickness measurement using microwaves  

DOE Patents [OSTI]

The method for measuring the thickness of a material which transmits a detectable amount of microwave radiation includes irradiating the material with coherent microwave radiation tuned over a frequency range. Reflected microwave radiation is detected, the reflected radiation having maxima and minima over the frequency range as a result of coherent interference of microwaves reflected from reflecting surfaces of the material. The thickness of the material is determined from the period of the maxima and minima along with knowledge of the index of refraction of the material.

Woskov, Paul (Bedford, MA) [Bedford, MA; Lamar, David A. (West Richland, WA) [West Richland, WA

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Neural networks and separation of background and foregrounds in astrophysical sky maps  

E-Print Network [OSTI]

The Independent Component Analysis (ICA) algorithm is implemented as a neuralnetwork for separating signals of different origin in astrophysical sky maps.Due to its self-organizing capability, it works without prior assumptions onthe signals, neither on their frequency scaling, nor on the signal mapsthemselves; instead, it learns directly from the input data how to separate thephysical components, making use of their statistical independence. To test thecapabilities of this approach, we apply the ICA algorithm on sky patches, takenfrom simulations and observations, at the microwave frequencies, that are goingto be deeply explored in a few years on the whole sky, by the MicrowaveAnisotropy Probe (MAP) and by the {\\sc Planck} Surveyor Satellite. The maps areat the frequencies of the Low Frequency Instrument (LFI) aboard the {\\scPlanck} satellite (30, 44, 70 and 100 GHz), and contain simulated astrophysicalradio sources, Cosmic Microwave Background (CMB) radiation, and Galacticdiffuse emissions from thermal dust...

Baccigalupi, C; Burigana, C; De Zotti, G; Farusi, A; Maino, D; Maris, M; Perrotta, F; Salerno, E; Toffolatti, L; Tonazzini, A

2000-01-01T23:59:59.000Z

122

Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample  

DOE Patents [OSTI]

A system for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample.

Maerefat, Nicida L. (Sugar Land, TX); Parmeswar, Ravi (Marlton, NJ); Brinkmeyer, Alan D. (Tulsa, OK); Honarpour, Mehdi (Bartlesville, OK)

1994-01-01T23:59:59.000Z

123

Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample  

DOE Patents [OSTI]

A system is described for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample. 11 figs.

Maerefat, N.L.; Parmeswar, R.; Brinkmeyer, A.D.; Honarpour, M.

1994-08-23T23:59:59.000Z

124

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

125

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

126

The Big Bang, COBE, and the Relic Radiation of Creation (LBNL Science at the Theater)  

ScienceCinema (OSTI)

Berkeley Lab's George Smoot won the 2006 Physics Nobel Prize, together with John Mather of NASA Goddard Space Flight Center, for "the discovery of the blackbody form and anisotropy of the cosmic microwave background radiation." The anisotropy showed as small variations in the map of the early universe. This research looks back into the infant universe and provides a better understanding of the origin of galaxies and stars. The cosmic background radiation is a tool to understand the structure and history of the universe and the structure of space-time. These observations have provided increased support for the big bang theory of the universe's origin. The Cosmic Background Explorer (COBE) NASA satellite, launched in 1989, carries instruments that measured various aspects of cosmic microwave background radiation, and produced the data for these compelling scientific results, which opened up a field that continues very actively today.

Smoot, George

2011-04-28T23:59:59.000Z

127

Microwave treatment of vulcanized rubber  

DOE Patents [OSTI]

A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds broken by microwave radiation. The direct application of microwaves in combination with uniform heating of the crumb rubber renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger particle sizes and/or loading levels of the treated crumb rubber can be used in new rubber mixtures to produce recycled composite products with good properties.

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

2002-07-16T23:59:59.000Z

128

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

129

Note: Cryogenic coaxial microwave filters  

SciTech Connect (OSTI)

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

130

Microwave sintering of single plate-shaped articles  

DOE Patents [OSTI]

Apparatus and method are disclosed for high temperature sintering of plate-shaped articles of alumina, magnesia, silica, yttria, zirconia, and mixtures thereof using microwave radiation. An article is placed within a sintering structure located within a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled. 2 figs.

Katz, J.D.; Blake, R.D.

1995-07-11T23:59:59.000Z

131

The Electrodeless Discharge Lamps Coated with the Titania Thin Film for Photocatalysis in a Microwave Field  

E-Print Network [OSTI]

photochemical and photocatalytic reactions for degradation of organic pollutants. The electrodeless discharge lamp (EDL) generates UV/VIS radiation when placed into the microwave field and is connected to the objective of microwave photochemistry [1]. The degradation of mono-chloroacetic acid (MCAA) by microwave

Cirkva, Vladimir

132

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

133

Microwave Radiometer (MWR) Handbook  

SciTech Connect (OSTI)

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

134

Dark radiation from the axino solution of the gravitino problem  

E-Print Network [OSTI]

Current observations of the cosmic microwave background could confirm an increase in the radiation energy density after primordial nucleosynthesis but before photon decoupling. We show that, if the gravitino problem is solved by a light axino, dark (decoupled) radiation emerges naturally in this period leading to a new upper bound on the reheating temperature T_R < 10^{11} GeV. In turn, successful thermal leptogenesis might predict such an increase. The Large Hadron Collider could endorse this opportunity. At the same time, axion and axino can naturally form the observed dark matter.

Jasper Hasenkamp

2011-12-13T23:59:59.000Z

135

Hubble diagrams of soft and hard radiation sources in the graviton background: to an apparent contradiction between supernova 1a and gamma-ray burst observations  

E-Print Network [OSTI]

In the sea of super-strong interacting gravitons, non-forehead collisions with gravitons deflect photons, and this deflection may differ for soft and hard radiations. As a result, the Hubble diagram would not be a universal function and it will have a different view for such sources as supernovae in visible light and gamma-ray bursts. Observations of these two kinds are compared here with the limit cases of the Hubble diagram.

Michael A. Ivanov

2007-01-10T23:59:59.000Z

136

High brightness microwave lamp  

DOE Patents [OSTI]

An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

2003-09-09T23:59:59.000Z

137

Microwave hemorrhagic stroke detector  

DOE Patents [OSTI]

The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stroke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

2002-01-01T23:59:59.000Z

138

Microwave hemorrhagic stroke detector  

DOE Patents [OSTI]

The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stoke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

2007-06-05T23:59:59.000Z

139

Microwave-enhanced chemical processes  

DOE Patents [OSTI]

A process is disclosed for the disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400 C in the presence of microwave radiation for a time sufficient breaks the hydrocarbon chlorine bonds. Detoxification values in excess of 80 are provided and further detoxification of the bed is followed by additional disposal of toxic wastes. 1 figure.

Varma, R.

1990-06-19T23:59:59.000Z

140

Earth X-ray albedo for cosmic X-ray background radiation in the 1--1000 keV band  

E-Print Network [OSTI]

We present calculations of the reflection of the cosmic X-ray background (CXB) by the Earth's atmosphere in the 1--1000 keV energy range. The calculations include Compton scattering and X-ray fluorescent emission and are based on a realistic chemical composition of the atmosphere. Such calculations are relevant for CXB studies using the Earth as an obscuring screen (as was recently done by INTEGRAL). The Earth's reflectivity is further compared with that of the Sun and the Moon -- the two other objects in the Solar system subtending a large solid angle on the sky, as needed for CXB studies.

E. Churazov; S. Sazonov; R. Sunyaev; M. Revnivtsev

2008-02-11T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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.


141

Electric Dipole Radiation from Spinning Dust Grains  

E-Print Network [OSTI]

We discuss the rotational excitation of small interstellar grains and the resulting electric dipole radiation from spinning dust. Attention is given to excitation and damping of rotation by: collisions with neutrals; collisions with ions; plasma drag; emission of infrared radiation; emission of microwave radiation; photoelectric emission; and formation of H_2 on the grain surface. We introduce dimensionless functions F and G which allow direct comparison of the contributions of different mechanisms to rotational drag and excitation. Emissivities are estimated for dust in different phases of the interstellar medium, including diffuse HI, warm HI, low-density photoionized gas, and cold molecular gas. Spinning dust grains can explain much, and perhaps all, of the 14-50 GHz background component recently observed in CBR studies. It should be possible to detect rotational emission from small grains by ground-based observations of molecular clouds.

B. T. Draine; A. Lazarian

1998-02-18T23:59:59.000Z

142

Minimizing the background radiation in the new neutron time-of-flight facility at CERN FLUKA Monte Carlo simulations for the optimization of the n_TOF second experimental line  

E-Print Network [OSTI]

At the particle physics laboratory CERN in Geneva, Switzerland, the Neutron Time-of-Flight facility has recently started the construction of a second experimental line. The new neutron beam line will unavoidably induce radiation in both the experimental area and in nearby accessible areas. Computer simulations for the minimization of the background were carried out using the FLUKA Monte Carlo simulation package. The background radiation in the new experimental area needs to be kept to a minimum during measurements. This was studied with focus on the contributions from backscattering in the beam dump. The beam dump was originally designed for shielding the outside area using a block of iron covered in concrete. However, the backscattering was never studied in detail. In this thesis, the fluences (i.e. the flux integrated over time) of neutrons and photons were studied in the experimental area while the beam dump design was modified. An optimized design was obtained by stopping the fast neutrons in a high Z mat...

Bergström, Ida; Elfgren, Erik

2013-06-11T23:59:59.000Z

143

CONTRIBUTION OF GAMMA-RAY-LOUD RADIO GALAXIES' CORE EMISSIONS TO THE COSMIC MeV AND GeV GAMMA-RAY BACKGROUND RADIATION  

SciTech Connect (OSTI)

The Fermi gamma-ray satellite has recently detected gamma-ray emissions from radio galaxy cores. From these samples, we first examine the correlation between the luminosities at 5 GHz, L{sub 5GHz}, and at 0.1-10 GeV, L{sub {gamma}}, of gamma-ray-loud radio galaxies. We find that the correlation is significant with L{sub {gamma}}{proportional_to}L{sup 1.16}{sub 5GHz} based on a partial correlation analysis. Using this correlation and the radio luminosity function (RLF) of radio galaxies, we explore the contribution of gamma-ray-loud radio galaxies to the unresolved extragalactic gamma-ray background (EGRB). The gamma-ray luminosity function is obtained by normalizing the RLF to reproduce the source-count distribution of the Fermi gamma-ray-loud radio galaxies. We find that gamma-ray-loud radio galaxies can explain {approx}25% of the unresolved Fermi EGRB flux above 100 MeV and will also make a significant contribution to the EGRB in the 1-30 MeV energy band. Since blazars explain 22% of the EGRB above 100 MeV, radio-loud active galactic nucleus populations explain {approx}47% of the unresolved EGRB. We further make an interpretation on the origin of the EGRB. The observed EGRB spectrum at 0.2-100 GeV does not show an absorption signature by the extragalactic background light. Thus, the dominant population of the origin of EGRB at very high energy (>30 GeV) might be either nearby gamma-ray-emitting sources or sources with very hard gamma-ray spectra.

Inoue, Yoshiyuki, E-mail: yinoue@kusastro.kyoto-u.ac.jp [Department of Astronomy, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

2011-05-20T23:59:59.000Z

144

Background canceling surface alpha detector  

DOE Patents [OSTI]

A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs.

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

1996-06-11T23:59:59.000Z

145

Non Thermal Features in the Cosmic Neutrino Background  

E-Print Network [OSTI]

I review some of the basic information on the Cosmic Neutrino Background momentum distribution. In particular, I discuss how present data from several cosmological observables such as Big Bang Nucleosynthesis, Cosmic Microwave Background and Large Scale Structure power spectrum constrain possible deviations from a standard Fermi-Dirac thermal distribution.

G. Mangano

2006-03-22T23:59:59.000Z

146

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

147

Microwave processing of ceramics  

SciTech Connect (OSTI)

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

148

Microwave processing of ceramics  

SciTech Connect (OSTI)

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

149

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

150

George Smoot, Blackbody, and Anisotropy of the Cosmic Microwave Background  

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

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151

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

152

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

153

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

154

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

155

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

156

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.

157

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

158

Microwave determination of location and speed of an object inside a pipe  

DOE Patents [OSTI]

Apparatus and method are described for measuring the location and speed of an object, such as instrumentation on a movable platform, disposed within a pipe, using continuous-wave, amplitude-modulated microwave radiation.

Sinha, Dipen N. (Los Alamos, NM)

2010-12-14T23:59:59.000Z

159

Microwave and Radio Frequency Workshop  

Broader source: Energy.gov [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 ...

160

Microwave-assisted synthesis of transition metal phosphide  

SciTech Connect (OSTI)

A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

Viswanathan, Tito

2014-12-30T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Radiation: Facts, Risks and Realities  

E-Print Network [OSTI]

of Radiation 3 Understanding Radiation Risks 6 Naturally Occurring (Background) Radiation 7 Man-Made Radiation, beta particles and gamma rays. Other types, such as x-rays, can occur naturally or be machine-produced. Scientists have also learned that radiation sources are naturally all around us. Radiation can come from

162

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

163

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

164

The Deconvolution of Lunar Brightness Temperature based on Maximum Entropy Method using Chang'E-2 Microwave Data  

E-Print Network [OSTI]

A passive and multi-channel microwave sounder onboard Chang'E-2 orbiter has successfully performed microwave observation of the lunar surface and subsurface structure. Compared with Chang'E-1 orbiter, Chang'E-2 orbiter obtained more accurate and comprehensive microwave brightness temperature data which is helpful for further research. Since there is a close relationship between microwave brightness temperature data and some related properties of the lunar regolith, such as the thickness, temperature and dielectric constant, so precise and high resolution brightness temperature is necessary for such research. However, through the detection mechanism of the microwave sounder, the brightness temperature data acquired from the microwave sounder is weighted by the antenna radiation pattern, so the data is the convolution of the antenna radiation pattern and the lunar brightness temperature. In order to obtain the real lunar brightness temperature, a deconvolution method is needed. The aim of this paper is to solve...

Xing, Shuguo; Feng, Jianqing; Li, Chunlai

2014-01-01T23:59:59.000Z

165

Estimating radiological background using imaging spectroscopy  

SciTech Connect (OSTI)

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

166

Selected applications of microwave radiometric techniques  

E-Print Network [OSTI]

Measurements at 31. 4 GHz of an Oil Film on a Water Surface 75 80 93 96 97 114 122 126 127 132 LIST OF FIGURES ~Fi ure ~Pa e III-1 Laboratory measurements of the dielectric properties of moist sand 24 III-2 III-3 III-4 Effects of increasing.... Based on the characteristic of all bodies to radiate electromagnetic energy at a rate depen- dent upon their temperature, surface structure, and elec- tromagnetic properties, the microwave radiometer provides an all-weather, day-night means...

Jean, Buford Randall

1971-01-01T23:59:59.000Z

167

Issues in microwave power systems engineering  

SciTech Connect (OSTI)

The key issues in microwave power system engineering are beam safety, frequency allocation, and affordability. These major issues are presented, discussed, and suggestions for resolving them are offered. The issue of beam safety can be captured in the phrase ``Fear of Frying.`` Can a properly engineered beamed power safety system allay the public perception of microwave radiation dangers? Openness, visibility, and education may be keys to resolving this issue satisfactorily. ``Not in my Spectrum`` is a phrase that is frequently encountered in connection with the issue of where can the microwave power beam frequency be located. International cooperation may provide a part of the solution to this issue. ``Wow, that much?`` is a phrase encountered when dealing with the issue of economic affordability of large beamed power systems. A phased engineering approach for multiple uses even during construction is presented to aid in garnering revenue during the system build phase. Also, dual mode dc-RF converters are encouraged for bi-directional power flow utility and economies of scale in production.

Dickinson, R.M. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

1996-12-31T23:59:59.000Z

168

Scale-invariance as the origin of dark radiation?  

E-Print Network [OSTI]

Recent cosmological data favour R^2-inflation and some amount of non-standard dark radiation in the Universe. We show that a framework of high energy scale invariance can explain these data. The spontaneous breaking of this symmetry provides gravity with the Planck mass and particle physics with the electroweak scale. We found that the corresponding massless Nambu--Goldstone bosons -- dilatons -- are produced at reheating by the inflaton decay right at the amount needed to explain primordial abundances of light chemical elements and anisotropy of the cosmic microwave background. Then we extended the discussion on the interplay with Higgs-inflation and on general class of inflationary models where dilatons are allowed and may form the dark radiation. As a result we put a lower limit on the reheating temperature in a general scale invariant model of inflation.

Dmitry Gorbunov; Anna Tokareva

2014-11-11T23:59:59.000Z

169

Dark radiation from particle decay: cosmological constraints and opportunities  

SciTech Connect (OSTI)

We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and structure formation. Bounds on branching ratios and mass hierarchies depend in a unique way on the time of decay. We demonstrate their power to exclude well-motivated scenarios taking the example of the lightest ordinary sparticle decaying into the gravitino. We point out signatures and opportunities in cosmological observations and structure formation. For example, if there are two dark decay modes, dark radiation and the observed dark matter with adjustable free-streaming can originate from the same decaying particle, solving small-scale problems of structure formation. Hot dark matter mimicking a neutrino mass scale as deduced from cosmological observations can arise and possibly be distinguished after a discovery. Our results can be used as a guideline for model building.

Hasenkamp, Jasper; Kersten, Jörn, E-mail: Jasper.Hasenkamp@desy.de, E-mail: Joern.Kersten@desy.de [II. Institute for Theoretical Physics, University of Hamburg, 22761 Hamburg (Germany)

2013-08-01T23:59:59.000Z

170

Dark radiation from particle decay: cosmological constraints and opportunities  

E-Print Network [OSTI]

We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and structure formation. Bounds on branching ratios and mass hierarchies depend in a unique way on the time of decay. We demonstrate their power to exclude well-motivated scenarios taking the example of the lightest ordinary sparticle decaying into the gravitino. We point out signatures and opportunities in cosmological observations and structure formation. For example, if there are two dark decay modes, dark radiation and the observed dark matter with adjustable free-streaming can originate from the same decaying particle, solving small-scale problems of structure formation. Hot dark matter mimicking a neutrino mass scale as deduced from cosmological observations can arise and possibly be distinguished after a discovery. Our results can be used as a guideline for model building.

Jasper Hasenkamp; Jörn Kersten

2014-02-13T23:59:59.000Z

171

"Millikan oil drops" as quantum transducers between electromagnetic and gravitational radiation  

E-Print Network [OSTI]

Pairs of Planck-mass-scale drops of superfluid helium coated by electrons (i.e., "Millikan oil drops"), when levitated in the presence of strong magnetic fields and at low temperatures, can be efficient quantum transducers between electromagnetic (EM) and gravitational (GR) radiation. A Hertz-like experiment, in which EM waves are converted at the source into GR waves, and then back-converted at the receiver from GR waves back into EM waves, should be practical to perform. This would open up observations of the gravity-wave analog of the Cosmic Microwave Background from the extremely early Big Bang, and also communications directly through the interior of the Earth.

Raymond Y. Chiao

2007-02-25T23:59:59.000Z

172

Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter  

E-Print Network [OSTI]

Study of interaction between high absorption matter and microwave radiated energy is a subject of great importance. Especially, this concerns microwave spectroscopic characterization of biological liquids. Use of effective testing methods to obtain information about physical properties of different liquids on the molecular level is one of the most important problems in biophysics. However, the standard methods based on the microwave resonant techniques are not sufficiently suitable for biological liquids because the resonance peak in a resonator with high-loss liquids is so broad that the material parameters cannot be measured correctly. Although molecular vibrations of biomolecules may have microwave frequencies, it is not thought that such resonant coupling is significant due to their low energy compared with thermal energy and the strongly dampening aqueous environment. This paper presents an innovative microwave sensing technique for different types of lossy materials, including biological liquids. The te...

Vaisman, G; Shavit, R

2015-01-01T23:59:59.000Z

173

Simple method for highlighting the temperature distribution into a liquid sample heated by microwave power field  

SciTech Connect (OSTI)

Microwave induced heating is widely used in medical treatments, scientific and industrial applications. The temperature field inside a microwave heated sample is often inhomogenous, therefore multiple temperature sensors are required for an accurate result. Nowadays, non-contact (Infra Red thermography or microwave radiometry) or direct contact temperature measurement methods (expensive and sophisticated fiber optic temperature sensors transparent to microwave radiation) are mainly used. IR thermography gives only the surface temperature and can not be used for measuring temperature distributions in cross sections of a sample. In this paper we present a very simple experimental method for temperature distribution highlighting inside a cross section of a liquid sample, heated by a microwave radiation through a coaxial applicator. The method proposed is able to offer qualitative information about the heating distribution, using a temperature sensitive liquid crystal sheet. Inhomogeneities as smaller as 1°-2°C produced by the symmetry irregularities of the microwave applicator can be easily detected by visual inspection or by computer assisted color to temperature conversion. Therefore, the microwave applicator is tuned and verified with described method until the temperature inhomogeneities are solved.

Surducan, V.; Surducan, E.; Dadarlat, D. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

174

Microwave hematoma detector  

DOE Patents [OSTI]

The Microwave Hematoma Detector is a non-invasive device designed to detect and localize blood pooling and clots near the outer surface of the body. While being geared towards finding sub-dural and epi-dural hematomas, the device can be used to detect blood pooling anywhere near the surface of the body. Modified versions of the device can also detect pneumothorax, organ hemorrhage, atherosclerotic plaque in the carotid arteries, evaluate perfusion (blood flow) at or near the body surface, body tissue damage at or near the surface (especially for burn assessment) and be used in a number of NDE applications. The device is based on low power pulsed microwave technology combined with a specialized antenna, signal processing/recognition algorithms and a disposable cap worn by the patient which will facilitate accurate mapping of the brain and proper function of the instrument. The invention may be used for rapid, non-invasive detection of sub-dural or epi-dural hematoma in human or animal patients, detection of hemorrhage within approximately 5 cm of the outer surface anywhere on a patient's body.

Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA); Matthews, Dennis L. (Moss Beach, CA)

2001-01-01T23:59:59.000Z

175

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

176

Microwave generated electrodeless lamp for producing bright output  

SciTech Connect (OSTI)

A microwave generated electrodeless light source for producing a bright output comprising a lamp structure including a microwave chamber and a plasma medium-containing lamp envelope having a maximum dimension which is substantially less than a wavelength disposed therein. To provide the desired radiation output the interior of the chamber is coated with a UV-reflective material and the chamber has an opening for allowing UV radiation to exit, which is covered with a metallic mesh. The chamber is arranged to be near-resonant at a single wavelength, and the lamp envelope has a fill including mercury at an operating pressure of 1-2 atmospheres, while a power density of at least 250-300 (watts/cm/sup 3/) is coupled to the envelope to result in a relatively high deep UV output at a relatively high brightness.

Wood, Ch. H.; Ury, M. G.

1985-03-26T23:59:59.000Z

177

Microwave plasma CVD of NANO structured tin/carbon composites  

DOE Patents [OSTI]

A method for forming a graphitic tin-carbon composite at low temperatures is described. The method involves using microwave radiation to produce a neutral gas plasma in a reactor cell. At least one organo tin precursor material in the reactor cell forms a tin-carbon film on a supporting substrate disposed in the cell under influence of the plasma. The three dimensional carbon matrix material with embedded tin nanoparticles can be used as an electrode in lithium-ion batteries.

Marcinek, Marek (Warszawa, PL); Kostecki, Robert (Lafayette, CA)

2012-07-17T23:59:59.000Z

178

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

179

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

180

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...

Note: This page contains sample records for the topic "microwave background radiation" 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

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

182

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

183

ARM - Methane Background Information  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearchWarmingMethane Background Information Outreach Home Room News

184

Superluminal Velocity of Photons in a Gravitational Background  

E-Print Network [OSTI]

The influence of radiative corrections on the photon propagation in a gravitational background is investigated without the low-frequency approximation $\\omega \\ll m$. The conclusion is made in this way that the velocity of light can exceed unity.

I. B. Khriplovich

1994-11-20T23:59:59.000Z

185

Microwave Emission by Dust: Mechanisms, Properties and Prospects for ISM Studies  

E-Print Network [OSTI]

I review my work with Bruce Draine on dust emissivity at microwave frequencies (3 cm - 3 mm). This emissivity explains the recently detected "anomalous" component of the galactic foreground emission. Both small (a<0.001 micron) and large grains contribute to this emission. Small grains have electric dipole moments and emit while they rotate; the microwave emission of large grains is mostly due to magneto-dipole radiation. Most efficient magneto-dipole emitters are strongly magnetic, e.g. ferrimagnetic or ferromagnetic, materials. The relative role of the two mechanisms can be established through observations of microwave emissivity from dark clouds. New microwave window is a window of opportunity for interstellar studies. Magnetic fields inside dark clouds may be successfully studied via microwave polarization. Microwave emissivity constrains the abundance of strongly magnetic materials. For instance, the available data at 90 GHz indicate that not more than 5% of interstellar Fe is in the form of metallic iron grains or inclusions (e.g., in ``GEMS''). Future missions, e.g. MAP and PLANCK, will bring a wealth of microwave data that can be successfully used to study ISM. Such a study would be appreciated by cosmologists who franticly try to remove all foregrounds from their data.

Lazarian A

1998-11-03T23:59:59.000Z

186

LTS Background - Hanford Site  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs space control News & EventsModelingBackground

187

Radiative feedback and cosmic molecular gas: numerical method  

E-Print Network [OSTI]

We present results from self-consistent 3D numerical simulations of cosmic structure formation with a multi-frequency radiative transfer scheme and non-equilibrium molecular chemistry of 13 primordial species (e-, H, H+, H-, He, He+, He++, H2, H2+, D, D+, HD, HeH+), performed by using the simulation code GADGET. We describe our implementation and show tests for ionized sphere expansion in a static and dynamic density field around a central radiative source, and for cosmological abundance evolution coupled with the cosmic microwave background radiation. As a demonstrative application of radiative feedback on molecular gas, we run also cosmological simulations of early structure formation in a ~1Mpc size box. Our tests agree well with analytical and numerical expectations. Consistently with other works, we find that ionization fronts from central sources can boost H2 fractions in shock-compressed gas. The tight dependence on H2 lead to a corresponding boost of HD fractions, as well. We see a strong lowering of the the typical molecular abundances up to several orders of magnitudes which partially hinders further gas collapse of pristine neutral gas, and clearly suggests the need of re-ionized gas or metal cooling for the formation of the following generation of structures.

Margarita Petkova; Umberto Maio

2012-02-27T23:59:59.000Z

188

II. HISTORICAL BACKGROUND Since 1977 the University of Oregon Solar  

E-Print Network [OSTI]

2 II. HISTORICAL BACKGROUND Since 1977 the University of Oregon Solar Monitoring Laboratory has operated a solar radiation monitoring network in the Pacific Northwest. The number of stations participat of utilities headed by the Eugene Water and Electric Board initiated the Re- gional Solar Radiation Monitoring

Oregon, University of

189

SLAC All Access: Vacuum Microwave Device Department  

ScienceCinema (OSTI)

The Vacuum Microwave Device Department (VMDD) builds the devices that make SLAC's particle accelerators go. These devices, called klystrons, generate intense waves of microwave energy that rocket subatomic particles up to nearly the speed of light.

Haase, Andy

2014-06-13T23:59:59.000Z

190

Microwave coupling of frequency-locked Josephson junction arrays  

SciTech Connect (OSTI)

A high temperature superconducting YBa{sub 2}Cu{sub 3}O{sub y} array of five Josephson junctions designed with additional coupling lines has been developed to demonstrate the effects of frequency locking and impedance matching for applications such as oscillators, mixers, and detectors. The Josephson self-radiation power was directly detected by a superheterodyne receiver, and Shapiro steps were also measured. The Josephson self-radiation properties reveal good quality of phase locking and microwave coupling with external circuits. The maximum self-radiation power of our array is about 50 pW which is several ten times higher than that of a single Josephson junction, and its peak point exactly satisfies the Josephson current-voltage relation. The Shapiro-step measurements show that the behavior of current-voltage curve depends on the effective inductance of coupling lines which affects the total impedance of Josephson junction array and microwave coupling. The Josephson oscillation frequency was obtained up to about 880 GHz which is 73{percent} of the maximum available frequency calculated from the characteristic voltage of the Josephson junctions. Experimental results show that this type of Josephson junction array can improve the Josephson self-radiation power and increase the maximum detectable frequency. {copyright} {ital 1997 American Institute of Physics.}

Song, I.; Eom, Y.; Park, G. [Department of Physics, Sogang University, Seoul 100-611 (Korea)] [Department of Physics, Sogang University, Seoul 100-611 (Korea); Lee, E.; Park, S. [Electronic Materials Laboratory, Samsung Advanced Institute of Technology, Suwon (Korea)] [Electronic Materials Laboratory, Samsung Advanced Institute of Technology, Suwon (Korea)

1997-06-01T23:59:59.000Z

191

Ignition methods and apparatus using microwave energy  

DOE Patents [OSTI]

An ignition apparatus for a combustor includes a microwave energy source that emits microwave energy into the combustor at a frequency within a resonant response of the combustor, the combustor functioning as a resonant cavity for the microwave energy so that a plasma is produced that ignites a combustible mixture therein. The plasma preferably is a non-contact plasma produced in free space within the resonant cavity spaced away from with the cavity wall structure and spaced from the microwave emitter.

DeFreitas, Dennis Michael (Oxford, NY); Migliori, Albert (Santa Fe, NM)

1997-01-01T23:59:59.000Z

192

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

193

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

194

Broadband patterned magnetic microwave absorber  

SciTech Connect (OSTI)

It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7?mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple ?/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo, E-mail: guanjg@whut.edu.cn [State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Zhai, Pengcheng [School of Science, Wuhan University of Technology, Wuhan 430070 (China)

2014-07-28T23:59:59.000Z

195

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

196

Environmental assessment for the satellite power system-concept development and evaluation program-microwave health and ecological effects  

SciTech Connect (OSTI)

This report is concerned with the potential health and ecological effects of the microwave beam from the microwave power transmission system (MPTS) of the satellite power system (SPS). The report is written in the form of a detailed critical review of selected scientific articles from the published literature on the biological effects of nonionizing electromagnetic radiation, followed by an assessment of the possible effects of the SPS, based on exposure values for the reference system (US DOE and NASA, 1978).

Not Available

1980-11-01T23:59:59.000Z

197

FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: SOURCE CATALOG  

SciTech Connect (OSTI)

We present the list of point sources found in the Wilkinson Microwave Anisotropy Probe (WMAP) five-year maps. The technique used in the first-year and three-year analyses now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the Galactic plane to a 2 Jy limit, with SNR >4.7 in all bands in the least covered parts of the sky. The noise at high frequencies is still mainly radiometer noise, but at low frequencies the cosmic microwave background (CMB) anisotropy is the largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of which all but one can be identified with known radio sources. The sources seen by WMAP are not strongly polarized. Many of the WMAP sources show significant variability from year to year, with more than a 2:1 range between the minimum and maximum fluxes.

Wright, E. L.; Chen, X. [UCLA Physics and Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States); Odegard, N.; Hill, R. S.; Weiland, J. L. [Adnet Systems, Inc., 7515 Mission Dr., Suite A100, Lanham, MD 20706 (United States); Bennett, C. L.; Gold, B.; Larson, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Hinshaw, G.; Wollack, E.; Kogut, A. [Code 665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Jarosik, N.; Page, L.; Dunkley, J. [Department of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544-0708 (United States); Komatsu, E. [Department of Astronomy, University of Texas, Austin, 2511 Speedway, RLM 15.306, Austin, TX 78712 (United States); Nolta, M. R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8 (Canada); Spergel, D. N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544-1001 (United States); Halpern, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Limon, M. [Columbia Astrophysics Laboratory, 550 W. 120th St., 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)], E-mail: wright@astro.ucla.edu (and others)

2009-02-15T23:59:59.000Z

198

Microwave and plasma-assisted modification of composite fiber surface topography  

DOE Patents [OSTI]

The present invention introduces a novel method for producing an undulated surface on composite fibers using plasma technology and microwave radiation. The undulated surface improves the mechanical interlocking of the fibers to composite resins and enhances the mechanical strength and interfacial sheer strength of the composites in which they are introduced.

Paulauskas, Felix L. (Knoxville, TN); White, Terry L. (Knoxville, TN); Bigelow, Timothy S. (Knoxville, TN)

2003-02-04T23:59:59.000Z

199

Possible generation of $?$-ray laser by electrons wiggling in a background laser  

E-Print Network [OSTI]

The possibility of $\\gamma-$ray laser generation by the radiation of wiggling electrons in an usual background laser is discussed.

Qi-Ren Zhang

2014-08-13T23:59:59.000Z

200

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

Note: This page contains sample records for the topic "microwave background radiation" 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

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

202

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

203

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

204

Controlled zone microwave plasma system  

DOE Patents [OSTI]

An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.

Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxville, TN)

2009-10-20T23:59:59.000Z

205

6, 54275456, 2006 Passive microwave  

E-Print Network [OSTI]

ACPD 6, 5427­5456, 2006 Passive microwave 3-D polarization effects from rainy clouds A. Battaglia radiometers A. Battaglia 1 , C. Simmer 1 , and H. Czekala 2 1 Meteorological Institute, University of Bonn April 2006 ­ Published: 27 June 2006 Correspondence to: A. Battaglia (batta@uni-bonn.de) 5427 #12;ACPD 6

Boyer, Edmond

206

Analysis of microwave leaky modes propagating through laser plasma filaments column waveguide  

SciTech Connect (OSTI)

A plasma column waveguide formed by a bundle of closely spaced plasma filaments induced by the propagation of ultrafast laser pulses in air and revived by a longer infrared laser pulse is shown to support microwave radiation. We consider values of both the plasma electron density and microwave frequency for which the refractive index of plasma is lower than the refractive index of air; therefore, a leaky plasma waveguide can be realized in extremely high frequency band. The guiding mechanism does not require high conductance of the plasma and can be easily excited by using commercial femtosecond laser sources. A theoretical study of leaky mode characteristics of isotropic and homogeneous plasma column waveguides is investigated with several values of plasma and waveguide structure parameters. The microwave transmission loss was found to be mainly caused by the microwave leakage through the air-plasma interface and is weakly dependent on the plasma absorption. In spite of losses of microwaves caused by leakage and plasma absorption, it is shown to be much lower than both that accompanying to surface waves attaching to single conducting plasma wire and the free space propagation over distances in the order of the filament length, which opens exciting perspectives for short distance point to point wireless transmission of pulsed-modulated microwaves.

Alshershby, Mostafa; Hao Zuoqiang; Lin Jingquan [School of Science, Changchun University of Science and Technology, Changchun 130022 (China)

2012-12-15T23:59:59.000Z

207

Microwave transient analyzer  

DOE Patents [OSTI]

A method and apparatus for capturing and recording indications of frequency content of electromagnetic signals and radiation is disclosed including a laser light source (12) and a Bragg cell (14) for deflecting a light beam (22) at a plurality of deflection angles (36) dependent upon frequency content of the signal. A streak camera (26) and a microchannel plate intensifier (28) are used to project Bragg cell (14) output onto either a photographic film (32) or a charge coupled device (CCD) imager (366). Timing markers are provided by a comb generator (50) and a one shot generator (52), the outputs of which are also routed through the streak camera (26) onto the film (32) or the CCD imager (366). Using the inventive method, the full range of the output of the Bragg cell (14) can be recorded as a function of time.

Gallegos, Cenobio H. (Santa Fe, NM); Ogle, James W. (Santa Fe, NM); Stokes, John L. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

208

Microwave transient analyzer  

DOE Patents [OSTI]

A method and apparatus for capturing and recording indications of frequency content of electromagnetic signals and radiation is disclosed including a laser light source and a Bragg cell for deflecting a light beam at a plurality of deflection angles dependent upon frequency content of the signal. A streak camera and a microchannel plate intensifier are used to project Bragg cell output onto either a photographic film or a charge coupled device (CCD) imager. Timing markers are provided by a comb generator and a one shot generator, the outputs of which are also routed through the streak camera onto the film or the CCD imager. Using the inventive method, the full range of the output of the Bragg cell can be recorded as a function of time. 5 figs.

Gallegos, C.H.; Ogle, J.W.; Stokes, J.L.

1992-11-24T23:59:59.000Z

209

CORRELATIONS IN THE (SUB)MILLIMETER BACKGROUND FROM ACT Multiplication-Sign BLAST  

SciTech Connect (OSTI)

We present measurements of the auto- and cross-frequency correlation power spectra of the cosmic (sub)millimeter background at 250, 350, and 500 {mu}m (1200, 860, and 600 GHz) from observations made with the Balloon-borne Large Aperture Submillimeter Telescope (BLAST); and at 1380 and 2030 {mu}m (218 and 148 GHz) from observations made with the Atacama Cosmology Telescope (ACT). The overlapping observations cover 8.6 deg{sup 2} in an area relatively free of Galactic dust near the south ecliptic pole. The ACT bands are sensitive to radiation from the cosmic microwave background, to the Sunyaev-Zel'dovich effect from galaxy clusters, and to emission by radio and dusty star-forming galaxies (DSFGs), while the dominant contribution to the BLAST bands is from DSFGs. We confirm and extend the BLAST analysis of clustering with an independent pipeline and also detect correlations between the ACT and BLAST maps at over 25{sigma} significance, which we interpret as a detection of the DSFGs in the ACT maps. In addition to a Poisson component in the cross-frequency power spectra, we detect a clustered signal at 4{sigma}, and using a model for the DSFG evolution and number counts, we successfully fit all of our spectra with a linear clustering model and a bias that depends only on redshift and not on scale. Finally, the data are compared to, and generally agree with, phenomenological models for the DSFG population. This study demonstrates the constraining power of the cross-frequency correlation technique to constrain models for the DSFGs. Similar analyses with more data will impose tight constraints on future models.

Hajian, Amir; Battaglia, Nick; Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Viero, Marco P.; Bock, James J. [California Institute of Technology, Pasadena, CA 91125 (United States); Addison, Graeme [Department of Astrophysics, Oxford University, Oxford, OX1 3RH (United Kingdom); Aguirre, Paula [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica, Casilla 306, Santiago 22 (Chile); Appel, John William; Duenner, Rolando; Essinger-Hileman, Thomas; Fowler, Joseph W.; Hincks, Adam D. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Das, Sudeep; Dunkley, Joanna [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Devlin, Mark J.; Dicker, Simon R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, Piscataway, NJ 08854-8019 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hasselfield, Matthew [Laboratoire APC, Universite Paris Diderot, 75205 Paris (France); Hilton, Matt [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban 4041 (South Africa); and others

2012-01-01T23:59:59.000Z

210

Combination biological and microwave treatments of used rubber products  

DOE Patents [OSTI]

A process and resulting product is provided in which a vulcanized solid particulate, such as vulcanized crumb rubber, has select chemical bonds altered by biotreatment with thermophillic microorganisms selected from natural isolates from hot sulfur springs. Following the biotreatment, microwave radiation is used to further treat the surface and to treat the bulk interior of the crumb rubber. The resulting combined treatments render the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels and sizes of the treated crumb rubber can be used in new rubber mixtures and good properties obtained from the new recycled products.

Fliermans, Carl B. (Augusta, GA); Wicks, George G. (Aiken, SC)

2002-01-01T23:59:59.000Z

211

Polycrystal diamond growth in a microwave plasma torch  

SciTech Connect (OSTI)

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

212

Influence of Extraterrestrial Radiation on Radiation Portal Monitors  

SciTech Connect (OSTI)

Cosmic radiation and solar flares can be a major source of background radiation at the Earth’s surface. This paper examines the relationship between extraterrestrial radiation and the detectable background in radiation portal monitors used for homeland security applications. Background radiation data from 13 radiation portal monitor facilities are examined and compared against external sources of data related to extraterrestrial radiation, including measurements at neutron monitors located at 53 cosmic-ray observatories around the Earth, four polar orbiting satellites, three geostationary satellites, ground-based geomagnetic field data from observatories around the Earth, a solar magnetic index, solar radio flux data, and sunspot activity data. Four-years (January 2003 through December 2006) of data are used in this study, which include the latter part of Solar Cycle 23 as solar activity was on the decline. The analysis shows a significant relationship between some extraterrestrial radiation and the background detected in the radiation portal monitors. A demonstrable decline is shown in the average gamma ray and neutron background at the radiation portal monitors as solar activity declined over the period of the study.

Keller, Paul E.; Kouzes, Richard T.

2009-06-01T23:59:59.000Z

213

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

214

Evaluation of ground-based remotely sensed liquid water cloud properties using shortwave radiation measurements  

E-Print Network [OSTI]

properties of low level water clouds. A number of remote sensing retrieval techniques provide either radar-only retrie- vals or combine millimeter-wave radar with microwave radiometer measurements (Frisch et al., 1995 radiation measurements from the ground. The remote sensing observations of radar reflectivity, microwave

Haak, Hein

215

Backgrounds of squeezed relic photons and their spatial correlations  

E-Print Network [OSTI]

We discuss the production of multi-photons squeezed states induced by the time variation of the (Abelian) gauge coupling constant in a string cosmological context. Within a fully quantum mechanical approach we solve the time evolution of the mean number of produced photons in terms of the squeezing parameters and in terms of the gauge coupling. We compute the first (amplitude interference) and second order (intensity interference) correlation functions of the magnetic part of the photon background. The photons produced thanks to the variation of the dilaton coupling are strongly bunched for the realistic case where the growth of the dilaton coupling is required to explain the presence of large scale magnetic fields and, possibly of a Faraday rotation of the Cosmic Microwave Background.

Massimo Giovannini

1999-08-19T23:59:59.000Z

216

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

217

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

218

Analysis of alpha backgrounds in the DEAP-1 detector  

E-Print Network [OSTI]

DEAP-1 is a 7 kg liquid argon dark matter detector used to prototype the tonne scale DEAP-3600 detector at SNOLAB.We present an analysis of the alpha particle backgrounds in DEAP-1 and isolate the radiations from various 222Rn daughters at various locations within the detector. The backgrounds will be removed by event position reconstruction and strict controls of material purity.

Kevin S. Olsen

2009-06-01T23:59:59.000Z

219

ESnet supports Sandia and APNIC IPv6 Background Radiation research  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct:DirectivesSAND2015-21271MostMirrorESnet's OSCARS

220

Background  

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

This concern is based on PTPC's interpretation of section 3.2 of BPA's Regional Dialogue Load Following Power Sales Agreement (Power Sales Agreement) template: 3.2 Take or Pay...

Note: This page contains sample records for the topic "microwave background radiation" 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

Background  

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

222

Background  

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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...

223

Background:  

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

files in future will now work correctly with that setting. (back to TOC) Importing the SSL Certificate in MSIE7 on Windows Vista Connecting to a Secure Socket Layer (SSL) enabled...

224

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solutions in the area to meet its space needs and increase employee efficiency and productivity For the past 10 years, BPA has provided work space for area employees through a...

225

Background  

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operations through another supplier if BPA was unable to supply Alcoa's Intalco smelter. In such circumstances, the demand shift would not materialize because the Intalco...

226

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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 -...

227

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V. RESPONSE TO COMMENTS: SPECIFIC CONTRACT ISSUES ... 14 a. Whether the ten year term of the Agreement is reasonable and consistent with sound business...

228

Background  

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program CumulusAMarch-6,-2015BSCmemo.pdfDECEMBERE P T E M0

229

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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program CumulusAMarch-6,-2015BSCmemo.pdfDECEMBERE P T E M0Tech

230

Background  

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

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231

Background  

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

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232

Background  

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

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233

Background  

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

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234

Background  

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

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235

Background  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program CumulusAMarch-6,-2015BSCmemo.pdfDECEMBERE P

236

Background  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program CumulusAMarch-6,-2015BSCmemo.pdfDECEMBERE PAGENCY

237

Background  

Office of Scientific and Technical Information (OSTI)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: Crystal structureComposite JC-118794ArgonneAnalysing the EffectEnergy Star

238

Background:  

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

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239

Background  

Office of Legacy Management (LM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou$0.C. 20545 OCTTO:March_

240

Background  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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 radiation" 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

Terahertz radiation mixer  

DOE Patents [OSTI]

A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

Wanke, Michael C. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA); Lee, Mark (Albuquerque, NM)

2008-05-20T23:59:59.000Z

242

Radiation Safety Edward O'Connell  

E-Print Network [OSTI]

tissues) #12;Sources of Background Radiation Exposure · Naturally occurring radioactive materialsRadiation Safety Edward O'Connell Radiation Safety Officer Stony Brook University New York #12;STONY BROOK UNIVERSITY & U. HOSPITAL MEDICAL CENTER #12;Why Radiation Safety · Working with radioactive

243

Microwave-assisted chemical process for treatment of hazardous waste: Annual report  

SciTech Connect (OSTI)

Microwave energy provides rapid in situ uniform heating and can be used to initiate chemical processes at moderate temperatures. We investigate the technical feasibility of microwave-assisted chemical processes for detoxification of liquid hazardous waste. Trichloroethylene, a major constituent of waste streams, was selected for this detoxification study. Experiments were performed to investigate the oxidative degradation of trichloroethylene over active carbons (with and without catalysts) in air streams with microwave in situ heating, and to examine the feasibility of regenerating the used carbons. This study established that trichloroethylene in a vapor stream can be adsorbed at room temperature on active carbon beds that are loaded with Cu and Cr catalysts. When the bed is heated by a microwave radiation to moderate temperatures (<400/sup 0/C) while a moist air stream is passed through it, the trichloroethylene is readily converted into less-noxious products such as HCl, CO, CO/sub 2/ and C/sub 2/H/sub 2/Cl/sub 2/. Conversion higher than 80% was observed. Furthermore, the used carbon bed can be conveniently regenerated by microwave heating while a moist-N/sub 2/ or moist-air stream is passed through the bed. 4 refs., 5 figs., 10 tabs.

Varma, R.; Nandi, S.P.; Cleaveland, D.C.

1987-10-01T23:59:59.000Z

244

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

245

Microwave-triggered laser switch  

DOE Patents [OSTI]

A high-repetition rate switch is described for delivering short duration, high-powered electrical pulses from a pulsed-charged dc power supply. The present invention utilizes a microwave-generating device such as a magnetron that is capable of producing high-power pulses at high-pulse repetition rates and fast-pulse risetimes for long periods with high reliability. The rail-gap electrodes provide a large surface area that reduces induction effects and minimizes electrode erosion. Additionally, breakdown is initiated in a continuous geometric fashion that also increases operating lifetime of the device.

Piltch, M.S.

1982-05-19T23:59:59.000Z

246

Microwave-triggered laser switch  

DOE Patents [OSTI]

A high-repetition rate switch for delivering short duration, high-power electrical pulses from a pulsed-charged dc power supply. The present invention utilizes a microwave-generating device such as a magnetron that is capable of producing high-power pulses at high-pulse repetition rates and fast-pulse risetimes for long periods with high reliability. The rail-gap electrodes provide a large surface area that reduces induction effects and minimizes electrode erosion. Additionally, breakdown is initiated in a continuous geometric fashion that also increases operating lifetime of the device.

Piltch, Martin S. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

247

Microwave Meals in a Hurry.  

E-Print Network [OSTI]

of time to prepare complete meals. Select dishes that are family favorites and use tested recipes . Learning to adapt recipes for microwave cooking comes. later with experience. In general, advance meal planning is the key to getting the most out.... For example, whole carrots stay hot longer than sliced carrots. Cooking and then serving food in the same dish extends holding time. So does wrapping or cov ering the food in plastic wrap or foil, or covering it with a lid. Cook foods with a long holding...

Haggard, Marilyn A.

1981-01-01T23:59:59.000Z

248

Microwave drying of ferric oxide pellets  

SciTech Connect (OSTI)

The application of microwave energy for the drying of ferric oxide pellets has been investigated and evaluated. It is shown that the microwave drying rates are much higher than those observed in the conventional process. Also there is some potential for improved quality of the product. As a stand-alone technology it is unlikely that microwave drying would be economical for pellets due to the low cost of conventional fuels. However, based on an understanding of the drying mechanisms in the conventional process and in the microwave process, it is shown that microwave-assisted drying offers considerable potential. In this hybrid process, the advantages of the two drying techniques are combined to provide an improved drying process.

Pickles, C.A.; Xia, D.K. [Queens` Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

1997-12-31T23:59:59.000Z

249

Electrodeless lamp energized by microwave energy  

SciTech Connect (OSTI)

This patent describes an electrodeless lamp. It comprises: a microwave cavity; a source of microwaves in communication with the cavity; a lamp envelope containing a plasma-forming medium mounted within the microwave cavity; a gas manifold for feeding gas to at least one gas passageway for directing a stream of gas to the outer surface of the envelope; a gas leak passageway leading from the gas manifold; a conductive mesh assembly for retaining microwaves within the cavity and permitting light to be emitted from the cavity. The assembly including gas flow blocking means for preventing the flow of gas through the gas leak passageway when the screen is in place in the lamp; and means for shutting off the source of microwaves when the gas pressure in the manifold drops below a predetermined value.

Ervin, R.M.; Perret, J.

1990-01-16T23:59:59.000Z

250

Microwave generated plasma light source apparatus  

SciTech Connect (OSTI)

A microwave generated plasma light source including a microwave generator, a microwave cavity having a light reflecting member forming at least a portion of the cavity, and a member transparent to light and opaque to microwaves disposed across an opening of the cavity opposite the feeding opening through which the microwave generator is coupled. An electrodeless discharge bulb is disposed at a position in the cavity such that the cavity operates as a resonant cavity at least when the bulb is emitting light. In the bulb is encapsulated at least one discharge light emissive substance. The bulb has a shape and is sufficiently small that the bulb acts substantially as a point light source.

Yoshizawa, K.; Ito, H.; Kodama, H.; Komura, H.; Minowa, Y.

1985-02-05T23:59:59.000Z

251

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

252

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

E-Print Network [OSTI]

4.3.2 Superconducting microstrip simulations 4.4 Impedance4.3 Superconducting microstrip . . . . . . . . . . 4.3.1Principles of superconductive devices and circuits, (second

Myers, Michael James

2010-01-01T23:59:59.000Z

253

Effects of Mass Varying Neutrinos on Cosmological Parameters as determined from the Cosmic Microwave Background  

E-Print Network [OSTI]

In models with a light scalar field (the `acceleron') coupled to neutrinos, neutrino masses depend on neutrino density. The resulting coupled system of mass varying neutrinos (MaVaNs) and the acceleron can act as a negative pressure fluid and is a candidate for dark energy \\cite{Fardon:2003eh} . MaVaNs also allow for higher $\\Sigma$m$_\

Akshay Ghalsasi; Ann E. Nelson

2014-05-04T23:59:59.000Z

254

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

E-Print Network [OSTI]

JCAP 06 (2012) 003, arXiv:1104.0015 N. Akopov, Z.Akopov, G. Aslanyan, L. Grigoryan “A-dependence of coherent

Aslanyan, Grigor; Aslanyan, Grigor

2012-01-01T23:59:59.000Z

255

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

256

Detec%on of compact sources in complex microwave and submillimeter backgrounds  

E-Print Network [OSTI]

to learn things about the origin the Universe, it's age, matter and energy content, geometry, dynamics, etc beams (non- gaussianity and non-circularity of the detectors), scanning strategy, calibration sources the detection and the characterization of a compact sources (shape, position angle, flux density estimation

Masci, Frank

257

Cosmological Perturbations of Quantum-Mechanical Origin and Anisotropy of the Microwave Background  

E-Print Network [OSTI]

Cosmological perturbations generated quantum-mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution of the produced temperature fluctuations of the CMBR is quite specific. An exact formula is derived for the angular correlation function of the temperature fluctuations caused by squeezed gravitational waves. The predicted angular pattern can, in principle, be revealed by the COBE-type observations.

L. P. Grishchuk

1993-04-01T23:59:59.000Z

258

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

259

THE WHITE MOUNTAIN POLARIMETER TELESCOPE AND AN UPPER LIMIT ON COSMIC MICROWAVE BACKGROUND POLARIZATION  

E-Print Network [OSTI]

. 2005; O'Dwyer et al. 2005; Donzelli 2006), and uses iden- tical aluminum coated carbon fiber reflectors gear.12 This table, as described in Mei

Timbie, Peter

260

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

E-Print Network [OSTI]

Loss tangent ? 0.01 a PETP (Mylar) PTFE (Teflon) Thicknessaluminum, but fortunately PP and PETP had higher contractionand made both the PP and PETP sheets loose even though these

Takahashi, Yuki David

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

The Anisotropy in the Cosmic Microwave Background At Degree Angular Scales.  

E-Print Network [OSTI]

are 36­39.5, 39.5­43, 43­46 GHz. The six channels in each radiometer view the sky in a single­axis parabola. The FWHM beam in K a band is 1:42 \\Sigma 0:02 ffi and in Q band is 1:04 \\Sigma 0:02 ffi . After

262

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

263

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

264

Cosmologies with Photon Creation and the 3K Relic Radiation Spectrum  

E-Print Network [OSTI]

A new Planckian distribution for cosmologies with photon creation is derived using thermodynamics and semiclassical considerations. This spectrum is preserved during the evolution of the universe and compatible with the present spectral shape of the cosmic microwave background radiation(CMBR). Accordingly, the widely spread feeling that cosmologies with continuous photon creation are definitely ruled out by the COBE limits on deviation of the CMBR spectrum from blackbody shape should be reconsidered. It is argued that a crucial test for this kind of cosmologies is provided by measurements of the CMBR temperature at high redshifts. For a given redshift $z$ greater than zero, the temperature is smaller than the one predicted by the standard FRW model.

J. A. S. Lima

1996-05-26T23:59:59.000Z

265

Uncertainty of microwave radiative transfer computations in rain  

E-Print Network [OSTI]

retrieval using new thermodynamic observations; and 3) to investigate the characteristics of four different RT codes. Firstly, a plane-parallel RT Model (RTM) of n layers in light rainfall was used for the analytical and computational derivation...

Hong, Sung Wook

2009-06-02T23:59:59.000Z

266

Microwave processing for carbide ceramics  

SciTech Connect (OSTI)

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

267

Microwave sintering of nanocrystalline ceramics  

SciTech Connect (OSTI)

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

268

Radiation Damage in Polarized Ammonia Solids  

E-Print Network [OSTI]

Solid NH3 and ND3 provide a highly polarizable, radiation resistant source of polarized protons and deuterons and have been used extensively in high luminosity experiments investigating the spin structure of the nucleon. Over the past twenty years, the UVA polarized target group has been instrumental in producing and polarizing much of the material used in these studies, and many practical considerations have been learned in this time. In this discussion, we analyze the polarization performance of the solid ammonia targets used during the recent JLab Eg4 run. Topics include the rate of polarization decay with accumulated charge, the annealing procedure for radiation damaged targets to recover polarization, and the radiation induced change in optimum microwave frequency used to polarize the sample. We also discuss the success we have had in implementing frequency modulation of the polarizing microwave frequency.

K. Slifer

2007-11-28T23:59:59.000Z

269

Numerical Study of a Propagating Non-Thermal Microwave Feature in a Solar Flare Loop  

E-Print Network [OSTI]

We analytically and numerically study the motion of electrons along a magnetic loop, to compare with the observation of the propagating feature of the non-thermal microwave source in the 1999 August 28 solar flare reported by Yokoyama et al. (2002). We model the electron motion with the Fokker-Planck equation and calculate the spatial distribution of the gyrosynchrotron radiation. We find that the microwave propagating feature does not correspond to the motion of electrons with a specific initial pitch angle. This apparent propagating feature is a consequence of the motion of an ensemble of electrons with different initial pitch angles, which have different time and position to produce strong radiation in the loop. We conclude that the non-thermal electrons in the 1999 August 28 flare were isotropically accelerated and then are injected into the loop.

T. Minoshima; T. Yokoyama

2008-06-24T23:59:59.000Z

270

Radiation: Radiation Control (Indiana)  

Broader source: Energy.gov [DOE]

It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...

271

Low density inorganic foams fabricated using microwaves  

SciTech Connect (OSTI)

The objective of our work was to determine if high temperature foams could be made using microwave heating; and if so, to investigate some of their properties. Several foams were made and their compressive strengths, tensile strengths and densities were determined. Foams were made of glass, metal-glass, glass-fiber, metal-glass-fiber, and fly ash. The microwave source used was a Litton model 1521 microwave oven which operated at 2.45 GHz and had an output of 700 watts.

Meek, T.T.; Blake, R.D.; Gregory, T.G.

1985-01-01T23:59:59.000Z

272

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

273

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

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

274

Internal and External Radioactive Backgrounds  

E-Print Network [OSTI]

Chapter 3 Internal and External Radioactive Backgrounds New physics is often discovered by pushing energies. With the current large mixing angle-MSW oscillation parameters, Borexino expects to observe 0.35 neutrino events per day per ton from 7Be in the energy window. Because there are so few events

275

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

276

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

277

Continuous, real time microwave plasma element sensor  

DOE Patents [OSTI]

Microwave-induced plasma is described for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. 3 figs.

Woskov, P.P.; Smatlak, D.L.; Cohn, D.R.; Wittle, J.K.; Titus, C.H.; Surma, J.E.

1995-12-26T23:59:59.000Z

278

E-Print Network 3.0 - atm radiation exposure Sample Search Results  

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

O'Connell Summary: tissues) 12;Sources of Background Radiation Exposure Naturally occurring radioactive materials... . Cosmic radiation. Fall-out from nuclear weapons...

279

RADIATION MONITORING  

E-Print Network [OSTI]

of Monitoring for Radiation Protection of Workers" in ICRPNo. 9, in "Advances in Radiation Protection and Dosimetry inDosimetry f o r Stray Radiation Monitoring on the CERN S i t

Thomas, R.H.

2010-01-01T23:59:59.000Z

280

BEDES Background | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in Review: Top Five EERE BlogAttachmentFlash2011-21 AuditInsulatedEnergyBackground BEDES

Note: This page contains sample records for the topic "microwave background radiation" 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

Gravitational wave radiometry: Mapping a stochastic gravitational wave background  

SciTech Connect (OSTI)

The problem of the detection and mapping of a stochastic gravitational wave background (SGWB), either cosmological or astrophysical, bears a strong semblance to the analysis of the cosmic microwave background (CMB) anisotropy and polarization, which too is a stochastic field, statistically described in terms of its correlation properties. An astrophysical gravitational wave background (AGWB) will likely arise from an incoherent superposition of unmodelled and/or unresolved sources and cosmological gravitational wave backgrounds (CGWB) are also predicted in certain scenarios. The basic statistic we use is the cross correlation between the data from a pair of detectors. In order to ''point'' the pair of detectors at different locations one must suitably delay the signal by the amount it takes for the gravitational waves (GW) to travel to both detectors corresponding to a source direction. Then the raw (observed) sky map of the SGWB is the signal convolved with a beam response function that varies with location in the sky. We first present a thorough analytic understanding of the structure of the beam response function using an analytic approach employing the stationary phase approximation. The true sky map is obtained by numerically deconvolving the beam function in the integral (convolution) equation. We adopt the maximum likelihood framework to estimate the true sky map using the conjugate gradient method that has been successfully used in the broadly similar, well-studied CMB map-making problem. We numerically implement and demonstrate the method on signal generated by simulated (unpolarized) SGWB for the GW radiometer consisting of the LIGO pair of detectors at Hanford and Livingston. We include 'realistic' additive Gaussian noise in each data stream based on the LIGO-I noise power spectral density. The extension of the method to multiple baselines and polarized GWB is outlined. In the near future the network of GW detectors, including the Advanced LIGO and Virgo detectors that will be sensitive to sources within a thousand times larger spatial volume, could provide promising data sets for GW radiometry.

Mitra, Sanjit [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India); Observatoire de la Cote d'Azur, BP 4229, 06304 Nice Cedex 4 (France); Dhurandhar, Sanjeev; Souradeep, Tarun [Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India); Lazzarini, Albert; Mandic, Vuk; Ballmer, Stefan [LIGO Laboratory, California Institute of Technology, MS 18-34, Pasadena, California 91125 (United States); Bose, Sukanta [Department of Physics, Washington State University, Pullman, Washington 99164-2814 (United States)

2008-02-15T23:59:59.000Z

282

High voltage ignition of high pressure microwave powered UV light sources  

SciTech Connect (OSTI)

Industrial microwave powered (electrodeless) light sources have been limited to quiescent pressures of {approximately}300 Torr of buffer gas and metal-halide fills. The predominant reason for such restrictions has been the inability to microwave ignite the plasma due to the collisionality of higher pressure fills and/or the electronegativity of halide bulb chemistries. Commercially interesting bulb fills require electric fields for ionization that are often large multiples of the breakdown voltage for air. Many auxiliary ignition methods are evaluated for efficiency and practicality before the choice of a high-voltage system with a retractable external electrode. The scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to its operating point (T{sub e} {approx} 0.5 eV). This process is currently being used in a new generation of lamps, which are using multi-atmospheric excimer laser chemistries and pressure and constituent enhanced metal-halide systems. At the present time, production prototypes produce over 900 W of radiation in a 30 nm band, centered at 308 nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce over 1 kW of radiation in 30 nm wide bands, centered about the wavelength of interest.

Frank, J.D.; Cekic, M.; Wood, C.H. [Fusion U.V. Curing Systems Corp., Gaithersburg, MD (United States)

1997-12-31T23:59:59.000Z

283

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

284

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?...

285

Numerical simulations of output pulse extraction from a high-power microwave compressor with a plasma switch  

SciTech Connect (OSTI)

Numerical simulations of the process of electromagnetic energy release from a high-power microwave pulse compressor comprising a gas-filled cavity and interference switch were carried out. A microwave plasma discharge in a rectangular waveguide H-plane tee was modeled with the use of the fully electromagnetic particle-in-cell code MAGIC. The gas ionization, plasma evolution, and interaction with RF fields accumulated within the compressor were simulated using different approaches provided by the MAGIC code: particle-in-cell approach accounting for electron-neutral collisions, gas conductivity model based on the concept of mobility, and hybrid modeling. The dependences of the microwave output pulse peak power and waveform on parameters that can be controlled in experiments, such as an external ionization rate, RF field amplitude, and background gas pressure, were investigated.

Shlapakovski, Anatoli; Beilin, Leonid; Bliokh, Yuri; Donskoy, Moshe; Krasik, Yakov E. [Physics Department, Technion, Haifa 32000 (Israel); Hadas, Yoav [Department of Applied Physics, Rafael, PO Box 2250, Haifa 31021 (Israel); Schamiloglu, Edl [Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

2014-05-07T23:59:59.000Z

286

E-Print Network 3.0 - accidental radiation evaluation Sample...  

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

environmental contamination from decommissioning of the Summary: from the naturally occurring background radiation - both for routine releases and accidental releases......

287

E-Print Network 3.0 - arrbod acute radiation Sample Search Results  

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

... 5 Summary: to years). Exposure to naturally occurring background radiation is an example of chronic exposure. Acute......

288

E-Print Network 3.0 - acute radiation syndrones Sample Search...  

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

... 5 Summary: to years). Exposure to naturally occurring background radiation is an example of chronic exposure. Acute......

289

E-Print Network 3.0 - acute radiation effects Sample Search Results  

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

... 5 Summary: to years). Exposure to naturally occurring background radiation is an example of chronic exposure. Acute......

290

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

291

Low Background Counting At SNOLAB  

SciTech Connect (OSTI)

It is a continuous and ongoing effort to maintain radioactivity in materials and in the environment surrounding most underground experiments at very low levels. These low levels are required so that experiments can achieve the required detection sensitivities for the detection of low-energy neutrinos, searches for dark matter and neutrinoless double-beta decay. SNOLAB has several facilities which are used to determine these low background levels in the materials and the underground environment. This proceedings will describe the SNOLAB High Purity Germanium Detector which has been in continuous use for the past five years and give results of many of the items that have been counted over that period. Brief descriptions of SNOLAB's alpha-beta and electrostatic counters will be given, and the radon levels at SNOLAB will be discussed.

Lawson, Ian; Cleveland, Bruce [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)

2011-04-27T23:59:59.000Z

292

Low background aspects of GERDA  

SciTech Connect (OSTI)

The GERDA experiment operates bare Germanium diodes enriched in {sup 76}Ge in an environment of pure liquid argon to search for neutrinoless double beta decay. A very low radioactive background is essential for the success of the experiment. We present here the research done in order to remove radio-impurities coming from the liquid argon, the stainless steel cryostat and the front-end electronics. We found that liquid argon can be purified efficiently from {sup 222}Rn. The main source of {sup 222}Rn in GERDA is the cryostat which emanates about 55 mBq. A thin copper shroud in the center of the cryostat was implemented to prevent radon from approaching the diodes. Gamma ray screening of radio-pure components for front-end electronics resulted in the development of a pre-amplifier with a total activity of less than 1 mBq {sup 228}Th.

Simgen, Hardy [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2011-04-27T23:59:59.000Z

293

Apparatus 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.

Babcock & Wilcox Technical Services Y-12, LLC (Oak Ridge, TN)

2008-04-15T23:59:59.000Z

294

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

295

Microwave joining of SiC  

SciTech Connect (OSTI)

The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on identification of the most effective joining methods for scale-up to large tube assemblies, including joining using SiC produced in situ from chemical precursors. During FY 1996, a new microwave applicator was designed, fabricated and tested that provides the capability for vacuum baking of the specimens and insulation and for processing under inert environment. This applicator was used to join continuous fiber-reinforced (CFCC) SiC/SiC composites using a polymer precursor to form a SiC interlayer in situ.

Silberglitt, R.; Ahmad, I.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States)] [and others

1997-04-01T23:59:59.000Z

296

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

297

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

SciTech Connect (OSTI)

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

298

Danger radiations  

ScienceCinema (OSTI)

Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

None

2011-04-25T23:59:59.000Z

299

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

300

NNSA to Conduct Aerial Radiation Assessment Survey over Joint...  

National Nuclear Security Administration (NNSA)

will be flying over Joint Base Andrews (JBA), Md., July 17, to measure naturally occurring background radiation. A helicopter may be seen flying at low altitudes while the...

Note: This page contains sample records for the topic "microwave background radiation" 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

Preliminary separation of galactic and cosmic microwave emission for the COBE Differential Microwave Radiometer  

SciTech Connect (OSTI)

Preliminary models of microwave emission from the Milky Way Galaxy based on COBE and other data are constructed for the purpose of distinguishing cosmic and Galactic signals. Differential Microwave Radiometer (DMR) maps, with the modeled Galactic emission removed, are fitted for a quadrupole distribution. Autocorrelation functions for individual Galactic components are presented. When Galactic emission is removed from the DMR data, the residual fluctuations are virtually unaffected, and therefore they are not dominated by any known Galactic emission component. 42 refs.

Bennet, C.L.; Smoot, G.F.; Hinshaw, G.; Wright, E.L.; Kogut, A.; De Amici, G.; Meyer, S.S.; Weiss, R.; Wilkinson, D.T.; Gulkis, S. (NASA, Goddard Space Flight Center, Greenbelt, MD (United States) Lawrence Berkeley Laboratory, CA (United States) California, University, Berkeley (United States) Universities Space Research Association, Boulder, CO (United States) California, University, Los Angeles (United States) MIT, Cambridge, MA (United States) Princeton University, NJ (United States) JPL, Pasadena, Ca (United States))

1992-09-01T23:59:59.000Z

302

Microwave Sensors Active and David G. Long  

E-Print Network [OSTI]

waves up through high energy gamma waves. Microwaves extend over an important part of the elec be classified as either passive (radiometers) or active (radars). Each sensor class provides unique insight instruments can be divided into two broad classes: pas- sive, known as radiometers, and active, known

Long, David G.

303

Farinon microwave end of life cycle  

SciTech Connect (OSTI)

This engineering report evaluates alternatives for the replacement of the Farinon microwave radio system. The system is beyond its expected life cycle and has decreasing maintainability. Principal applications supported by the Farinon system are two electrical utility monitor and control systems, the Integrated Transfer Trip System (ITTS), and the Supervisory Control and Data Acquisition (SCADA) system.

Poe, R.C.

1996-06-24T23:59:59.000Z

304

MICROWAVE PHOTOREACTOR FOR PHOTOCHEMICAL SYNTHESIS Milan Hajeka  

E-Print Network [OSTI]

and a IR pyrometer or fiber optic thermometer (Nortech), according to Figure 1. A round part (200 mm of the reaction mixture is monitored by the IR pyrometer or fiber optic thermometer. The MW photoreactor has been scientific discipline and microwave (MW) irradiation represents a new way to increase the efficiency of many

Cirkva, Vladimir

305

Environmental assessment: South microwave communication facilities  

SciTech Connect (OSTI)

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

306

Planar controlled zone microwave plasma system  

DOE Patents [OSTI]

An apparatus and method for initiating a process gas plasma. A conductive plate having a plurality of conductive fingers is positioned in a microwave applicator. An arc forms between the conductive fingers to initiate the formation of a plasma. A transport mechanism may convey process materials through the plasma. A spray port may be provided to expel processed materials.

Ripley, Edward B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Morrell, Jonathan S. (Knoxvlle, TN)

2011-10-04T23:59:59.000Z

307

Cavern background measurement with the ATLAS RPC system  

E-Print Network [OSTI]

The measurement of cavern background has been carried out systematically since the beginning of LHC, as soon as the luminosity produced a detectable signal, from L = 10^28 cm^2s^1 of the early 2010 operation up to L=10^28 cm^2s^1 at the end of 2011 proton-proton run, which is just 1/3 of the nominal LHC luminosity. The reason for this is to early foresee the running condition for the detector for the nominal LHC luminosity and beyond, in view of the super-LHC upgrade. Background Montecarlo calculations have been validated against data and the background map analysis pointed out hotspots due to localized cracks in the radiation shielding. The RPCs participated to this effort since the earliest stages providing an accurate correlation between luminosity and background, a 3D background map in the barrel region and a direct measurement of the cavern activation. Moreover due to the high sensitivity and very good signal to noise ratio of the proposed method, based on the gap current, the measurement was provided in...

Aielli, G; The ATLAS collaboration

2012-01-01T23:59:59.000Z

308

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

309

Latitudinal survey of middle atmospheric water vapor revealed by shipboard microwave spectroscopy. Master's thesis  

SciTech Connect (OSTI)

Water vapor is one of the most important greenhouse gases and is an important tracer of atmospheric motions in the middle atmosphere. It also plays an important role in the chemistry of the middle atmosphere and through its photodissociation by solar radiation, it is the major source of hydrogen escaping to space. Ground-based microwave measurements conducted in the 1980s have provided a fair understanding of the seasonal variation of mesospheric water vapor in the northern hemisphere mid-latitudes, but the global distribution of water vapor in the middle atmosphere is only beginning to be revealed by space-based measurements.

Schrader, M.L.

1994-05-01T23:59:59.000Z

310

Microwave-assisted synthesis of carbon nanotubes from tannin, lignin, and derivatives  

SciTech Connect (OSTI)

A method of synthesizing carbon nanotubes. In one embodiment, the method includes the steps of: (a) dissolving a first amount of a first transition-metal salt and a second amount of a second transition-metal salt in water to form a solution; (b) adding a third amount of tannin to the solution to form a mixture; (c) heating the mixture to a first temperature for a first duration of time to form a sample; and (d) subjecting the sample to a microwave radiation for a second duration of time effective to produce a plurality of carbon nanotubes.

Viswanathan, Tito

2014-06-17T23:59:59.000Z

311

Rotational state microwave mixing for laser cooling of complex diatomic molecules  

E-Print Network [OSTI]

We demonstrate the mixing of rotational states in the ground electronic state using microwave radiation to enhance optical cycling in the molecule yttrium (II) monoxide (YO). This mixing technique is used in conjunction with a frequency modulated and chirped continuous wave laser to slow longitudinally a cryogenic buffer gas beam of YO. We generate a measurable flux of YO below 10~m/s, directly loadable into a three-dimensional magneto-optical trap. This technique opens the door for laser cooling of molecules with more complex structure.

Yeo, Mark; Collopy, Alejandra L; Yan, Bo; Hemmerling, Boerge; Chae, Eunmi; Doyle, John M; Ye, Jun

2015-01-01T23:59:59.000Z

312

Network Requirements Workshop - Documents and Background Materials  

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

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

313

Apparatus and method for microwave processing of materials  

DOE Patents [OSTI]

Disclosed is a variable frequency microwave heating apparatus designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency heating apparatus is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity depending upon the material, including the state thereof, from which the workpiece is fabricated. The variable frequency microwave heating apparatus includes a microwave signal generator and a high-power microwave amplifier or a microwave voltage-controlled oscillator. A power supply is provided for operation of the high-power microwave oscillator or microwave amplifier. A directional coupler is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity. 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. 10 figs.

Johnson, A.C.; Lauf, R.J.; Bible, D.W.; Markunas, R.J.

1996-05-28T23:59:59.000Z

314

Apparatus and method for microwave processing of materials  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (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 heating apparatus (10) is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity (34) depending upon the material, including the state thereof, from which the workpiece (36) is fabricated. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a microwave voltage-controlled 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).

Johnson, Arvid C. (Lake in the Hills, IL); Lauf, Robert J. (Oak Ridge, TN); Bible, Don W. (Clinton, TN); Markunas, Robert J. (Chapel Hill, NC)

1996-01-01T23:59:59.000Z

315

New Technique for Retrieving Liquid Water Path over Land using Satellite Microwave Observations  

SciTech Connect (OSTI)

We present a new methodology for retrieving liquid water path over land using satellite microwave observations. As input, the technique exploits the Advanced Microwave Scanning Radiometer for earth observing plan (EOS) (AMSR-E) polarization-difference signals at 37 and 89 GHz. Regression analysis performed on model simulations indicates that over variable atmospheric and surface conditions the polarization-difference signals can be simply parameterized in terms of the surface emissivity polarization difference ({Delta}{var_epsilon}), surface temperature, liquid water path (LWP), and precipitable water vapor (PWV). The resulting polarization-difference parameterization (PDP) enables fast and direct (noniterative) retrievals of LWP with minimal requirements for ancillary data. Single- and dual-channel retrieval methods are described and demonstrated. Data gridding is used to reduce the effects of instrumental noise. The methodology is demonstrated using AMSR-E observations over the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site during a six day period in November and December, 2003. Single- and dual-channel retrieval results mostly agree with ground-based microwave retrievals of LWP to within approximately 0.04 mm.

Deeter, M.N.; Vivekanandan, J.

2005-03-18T23:59:59.000Z

316

Tree level Leptogenesis from Kalb-Ramond Torsion Background  

E-Print Network [OSTI]

The effect of torsion in theories of quantum gravity is known to be well described by an axion-like field which couples to matter as well as to gravitation and radiation gauge fields. In this note we consider a particular kind of torsion, arising from the Kalb-Ramond antisymmetric tensor field that appears in the gravitational multiplet of string theory. We investigate the implications for leptogenesis. It is shown that leptogenesis can occur even at tree-level and with only one generation of right-handed Majorana neutrinos, due to CP and CPT violation introduced by the background geometry.

M. de Cesare; Nick E. Mavromatos; Sarben Sarkar

2015-02-03T23:59:59.000Z

317

On the mechanism of electromagnetic microwave absorption in superfluid helium  

SciTech Connect (OSTI)

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

318

Nonlinear multiferroic phase shifters for microwave frequencies  

SciTech Connect (OSTI)

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

319

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

320

FDTD Analysis of Metamaterial Coated Microwave Antenna  

E-Print Network [OSTI]

of the metamaterial antenna is reduced over the classical design while the radiation pattern of the antenna remains virtually unchanged....

Cholleti, Vipin K.

2011-08-08T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

ARM - Measurement - Microwave narrowband brightness temperature  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARM Data DiscoverygovMeasurementsMicrowave

322

Quantum and Wave Dynamical Chaos in Superconducting Microwave Billiards  

E-Print Network [OSTI]

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

B. Dietz; A. Richter

2015-04-16T23:59:59.000Z

323

Quantum and Wave Dynamical Chaos in Superconducting Microwave Billiards  

E-Print Network [OSTI]

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

B. Dietz; A. Richter

2015-04-17T23:59:59.000Z

324

Cellular telephone-based radiation detection instrument  

DOE Patents [OSTI]

A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

Craig, William W. (Pittsburg, CA); Labov, Simon E. (Berkeley, CA)

2011-06-14T23:59:59.000Z

325

Hawking radiation in moving plasmas  

E-Print Network [OSTI]

Bi-metricity and Hawking radiation are exhibit in non-relativistic moving magnetohydrodynamics (MHD) plasma medium generating two Riemannian effective spacetimes. The first metric is a flat metric although the speed of "light" is given by a time dependent signal where no Hawking radiation or effective black holes are displayed. This metric comes from a wave equation which the scalar function comes from the scalar potential of the background velocity of the fluid and depends on the perturbation of the magnetic background field. The second metric is an effective spacetime metric which comes from the perturbation of the background MHD fluid. This Riemann metric exhibits a horizon and Hawking radiation which can be expressed in terms of the background constant magnetic field. The effective velocity is given Alfven wave velocity of plasma physics. The effective black hole found here is analogous to the optical black hole in moving dielectrics found by De Lorenci et al [Phys. Rev. D (2003)] where bi-metricity and Hawking radiation in terms of the electric field are found.

L. C. Garcia de Andrade

2005-09-07T23:59:59.000Z

326

The {ital COBE} Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. I. Limits and Detections  

SciTech Connect (OSTI)

The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer ({ital COBE}) spacecraft was designed primarily to conduct a systematic search for an isotropic cosmic infrared background (CIB) in 10 photometric bands from 1.25 to 240 {mu}m. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 {mu}m ({nu}{ital I}{sub {nu}} {lt} 64 nW m{sup {minus}2} sr{sup {minus}1}, 95{percent} confidence level) and at 240 {mu}m ({nu}{ital I}{sub {nu}} {lt} 28 nW m{sup {minus}2} sr{sup {minus}1}, 95{percent} confidence level). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the CIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 {mu}m data provide candidate detections of the CIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 {mu}m. No plausible solar system or Galactic source of the observed 140 and 240 {mu}m residuals can be identified, leading to the conclusion that the CIB has been detected at levels of {nu}{ital I}{sub {nu}} = 25 {plus_minus} 7 and 14 {plus_minus} 3 nW m{sup {minus}2} sr{sup {minus}1} at 140 and 240 {mu}m, respectively. The integrated energy from 140 to 240 {mu}m, 10.3 nW m{sup {minus}2} sr{sup {minus}1}, is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust production since the decoupling of the cosmic microwave background from matter. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society}

Hauser, M.G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)] [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Arendt, R.G. [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Kelsall, T.; Dwek, E. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Odegard, N.; Weiland, J.L.; Freudenreich, H.T. [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Raytheon STX, Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Reach, W.T. [California Institute of Technology, IPAC/JPL, MS 100-22, Pasadena, CA 91125 (United States)] [California Institute of Technology, IPAC/JPL, MS 100-22, Pasadena, CA 91125 (United States); Silverberg, R.F.; Moseley, S.H. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pei, Y.C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)] [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lubin, P. [Physics Department, University of California at Santa Barbara, Santa Barbara, CA 93106 (United States)] [Physics Department, University of California at Santa Barbara, Santa Barbara, CA 93106 (United States); Mather, J.C.; Shafer, R.A. [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Code 685, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Smoot, G.F. [Lawrence Berkeley Laboratory, Space Sciences Laboratory, Department of Physics, UC Berkeley, CA 94720 (United States)] [Lawrence Berkeley Laboratory, Space Sciences Laboratory, Department of Physics, UC Berkeley, CA 94720 (United States); Weiss, R. [Massachusetts Institute of Technology, Room 20F-001, Department of Physics, Cambridge, MA 02139 (United States)] [Massachusetts Institute of Technology, Room 20F-001, Department of Physics, Cambridge, MA 02139 (United States); Wilkinson, D.T. [Princeton University, Department of Physics, Jadwin Hall, Box 708, Princeton, NJ 08544 (United States)] [Princeton University, Department of Physics, Jadwin Hall, Box 708, Princeton, NJ 08544 (United States); Wright, E.L. [UCLA, Astronomy Department, Los Angeles, CA 90024-1562 (United States)] [UCLA, Astronomy Department, Los Angeles, CA 90024-1562 (United States)

1998-11-01T23:59:59.000Z

327

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

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

328

Tropical Cloud Properties and Radiative Heating Profiles  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

Mather, James

329

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

J. B. (1988) Internal Combustion Engine Fundamentals.novel microwave internal combustion engine ignition source,in the Internal Combustion Engine." SAE Technical Paper

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

330

Hydrogen recovery from extraterrestrial materials using microwave energy  

SciTech Connect (OSTI)

The feasibility of recovering hydrogen from extraterrestrial materials (lunar and Martian soils, asteroids) using microwave energy is presented. Reasons for harvesting and origins and locations of hydrogen are reviewed. Problems of hydrogen recovery are discussed in terms of hydrogen release characteristics and microwave coupling to insulating materials. From results of studies of hydrogen diffusivities (oxides, glasses) and tritium release (oxides) as well as studies of microwave coupling to ilmenite, alkali basalt and ceramic oxides it is concluded that using microwave energy in hydrogen recovery from extraterrestrial materials could be the basis for a workable process.

Tucker, D.S.; Vaniman, D.T.; Anderson, J.L.; Clinard, F.W. Jr.; Feber, R.C. Jr.; Frost, H.M.; Meek, T.T.; Wallace, T.C.

1984-01-01T23:59:59.000Z

331

advanced microwave circuits: Topics by E-print Network  

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

transition of photons in circuit quantum electrodynamics electrodynamics QED , superconduct- ing qubits are coupled with microwave photons in a trans- mission line and a...

332

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

of Emissions from HCCI Engines using a Consistent 3-Zoneof Microwave Plasma Combustion Engine (Part I: Concept ofPlasma Combustion Engine (Part II: Engine Performance of

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

333

Radiation detector  

DOE Patents [OSTI]

Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

Fultz, Brent T. (Berkeley, CA)

1983-01-01T23:59:59.000Z

334

Radiation detector  

DOE Patents [OSTI]

Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

Fultz, B.T.

1980-12-05T23:59:59.000Z

335

Solar Background Document 6 | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

6.pdf More Documents & Publications Solar Background Document 5 "Large Power Transformers and the U.S. Electric Grid" Report (June 2012) Dams and Energy Sectors...

336

Final Conservation Billing Credit Policy Supplement Background...  

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

December 17, 2014 Page 1 Final Conservation Billing Credit Policy Supplement Background and Need: This Conservation Billing Credit Policy Supplement describes how Bonneville Power...

337

THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE LOW RESOLUTION SPECTROMETER  

SciTech Connect (OSTI)

Absolute spectrophotometric measurements of diffuse radiation at 1 {mu}m to 2 {mu}m are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a {lambda}/{Delta}{lambda} {approx} 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 {mu}m <{lambda} < 2.1 {mu}m. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

Tsumura, K.; Arai, T.; Matsumoto, T.; Matsuura, S.; Murata, K. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronoutical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Brown, S.; Lykke, K.; Smith, A. [Optical Technology Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Hristov, V.; Levenson, L. R.; Mason, P. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Sullivan, I., E-mail: tsumura@ir.isas.jaxa.jp [Department of Physics, The University of Washington, Seattle, WA 98195 (United States); and others

2013-08-15T23:59:59.000Z

338

Microwave backgropund anisotropies, large-scale structure and cosmological parameters  

E-Print Network [OSTI]

We review how the various large-scale data constrain cosmological parameters and, consequently, theories for the origin of large-scale structure in the Universe. We discuss the form of the power spectrum implied by the correlation data of galaxies and argue by comparing the velocity field implied by the distribution of light with the observed velocity flows that the bias parameter, $b$, is likely to be constant in the linear regime. This then allows one to estimate the density parameter, $\\Omega$, and $b$ directly from the \\underline{data} on $\\xi(r)$ and the velocity fields. We show that it is consistent with low values of $\\Omega^{0.6}/b$. We discuss the ways to normalise the optical data at $z\\sim0$ directly to the COBE (or other microwave background) data. The data on high-$z$ \\underline{galaxies} allows one to further constrain the shape of the \\underline{primordial} power spectrum at scales which are non-linear today ($< 8h^{-1}$Mpc) and we discuss the consistency of the data with inflationary models normalised to the large-scale structure observations.

A. Kashlinsky

1993-11-18T23:59:59.000Z

339

E-Print Network 3.0 - advanced microwave scanning Sample Search...  

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

measurements. Near-field microwave reflectometer... -field microwave probe and signal processing section. This automated scanning 12;platform is easy to use... scanning...

340

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

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

Note: This page contains sample records for the topic "microwave background radiation" 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

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

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

342

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

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

343

National Ambient Radiation Database  

SciTech Connect (OSTI)

The U.S. Environmental Protection Agency (EPA) recently developed a searchable database and website for the Environmental Radiation Ambient Monitoring System (ERAMS) data. This site contains nationwide radiation monitoring data for air particulates, precipitation, drinking water, surface water and pasteurized milk. This site provides location-specific as well as national information on environmental radioactivity across several media. It provides high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and provides baseline data during routine conditions. The database and website are accessible at www.epa.gov/enviro/. This site contains (1) a query for the general public which is easy to use--limits the amount of information provided, but includes the ability to graph the data with risk benchmarks and (2) a query for a more technical user which allows access to all of the data in the database, (3) background information on ER AMS.

Dziuban, J.; Sears, R.

2003-02-25T23:59:59.000Z

344

Radiation dosimeter  

DOE Patents [OSTI]

A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

Fox, Richard J. (Oak Ridge, TN)

1983-01-01T23:59:59.000Z

345

Radiation dosimeter  

DOE Patents [OSTI]

A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

Fox, R.J.

1981-09-01T23:59:59.000Z

346

Radiative ?(1S) decays  

E-Print Network [OSTI]

— wW~ ii~ ~ + v~ 1''&WV'' V 0.20 0.45 0.70 ~y ~ EBFA~ 0.95 l.20 FIG. 4. Energy spectrum (normalized to beam energy) for Y~y2(h+h ) event candidates, with continuum data and ex- pected background from Y~m 2(h +h ) overplotted. 40 30— ~ 20— LLI IO— hl...PHYSICAL REVIEW 0 VOLUME 41, NUMBER 5 Radiative T(lS) decays 1 MARCH 1990 R. Fulton, M. Hempstead, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, and J. Whitmore Ohio State University, Columbus, Ohio 43210 W.-Y. Chen, J. Dominick, R. L. Mc...

Baringer, Philip S.

1990-03-01T23:59:59.000Z

347

International Conference on Microwave and High Frequency Heating Nottingham, UK, September 2013 Underwater Microwave Ignition of  

E-Print Network [OSTI]

-cost operation [4, 5]. Thermite reaction as a self-propagated, high-temperature synthesis (SHS) process, Localized microwave heating, underwater ignition, combustion. INTRODUCTION Self-propagated thermite reactions between metal-oxide and metals typically burn at high flame temperatures, and require high

Jerby, Eli

348

Microwaves and particle accelerators: a fundamental link  

SciTech Connect (OSTI)

John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society. (author)

Chattopadhyay, Swapan [Universities of Lancaster, Liverpool and Manchester and Cockcroft Institute, Cheshire (United Kingdom)

2011-07-01T23:59:59.000Z

349

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

350

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

351

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

352

Microwave sintering of sol-gel derived abrasive grain  

DOE Patents [OSTI]

A method is provided for making microwave-sintered, free flowing alpha alumina-based ceramic abrasive grain, under conditions effective to couple microwaves with calcined alpha alumina-based abrasive gain precursor and sinter it at a temperature of at least about 1150.degree. C.

Plovnick, Ross (St. Louis Park, MN); Celikkaya, Ahmet (Woodbury, MN); Blake, Rodger D. (Tuscon, AZ)

1997-01-01T23:59:59.000Z

353

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

354

Behavior of microwave-heated silicon carbide particles at frequencies of 2.0–13.5?GHz  

SciTech Connect (OSTI)

Silicon carbide is a key material in microwave (MW) processing and is used widely as a thermal insulator and catalytic agent. In this study, we experimentally investigated the temperature dependence of the MW-absorption properties of SiC particles at frequencies of 2.0–13.5?GHz. We heated SiC particles of different sizes using MW radiation. The heating behaviors of the particles were then compared with their MW-absorption properties. The heating behavior of the particles was dependent on their radii; this result was in keeping with theoretical predictions. Furthermore, the ?-SiC particles exhibited anomalous behaviors when subjected to microwave heating at temperatures of 1100?°C and higher. These behaviors were attributable to the transformation of ?-SiC into the ?-phase. The underlying mechanism for this transformation is discussed on the basis of the results of X-ray diffraction analysis.

Sugawara, H.; Hayashi, M.; Ishihara, S. [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro, Tokyo 152-8552 (Japan); Kashimura, K., E-mail: kashimura@isc.chubu.ac.jp [Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501 (Japan); Mitani, T.; Shinohara, N. [Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)

2014-07-21T23:59:59.000Z

355

RADIATION SAFETY TRAINING MANUAL Radiation Safety Office  

E-Print Network [OSTI]

RADIATION SAFETY TRAINING MANUAL Radiation Safety Office 130 DeSoto Street G-7 Parran with sources of ionizing radiation are required to be instructed in the basic principles of radiation protection and the potential risks of ionizing radiation. Radiation Safety Office personnel provide

Sibille, Etienne

356

Appendix G. Radiation Appendix G. Radiation  

E-Print Network [OSTI]

-made sources. People are exposed to naturally occurring radiation constantly. For example, cosmic radiation of radiation and its effects on the environment and biological systems. Radiation comes from natural and humanAppendix G. Radiation #12;#12;Appendix G. Radiation This appendix presents basic facts about

Pennycook, Steve

357

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

358

ARM - Field Campaign - Microwave Radiometer Profiler Evaluation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD) by Microtops Atmospheric Optical Depth (AOD) by Microtops ARM Data DiscoverygovCampaignsMicrowave

359

Ground-based Microwave Cloud Tomography  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky LearningGetGraphene's 3DRise |EnergyVehiclesMeasurementMicrowave

360

Manipulating microwaves with magnetic-dipolar-mode vortices  

SciTech Connect (OSTI)

There has been a surge of interest in the subwavelength confinement of electromagnetic fields. It is well known that, in optics, subwavelength confinement can be obtained from surface plasmon (quasielectrostatic) oscillations. In this article, we propose to realize subwavelength confinement in microwaves by using dipolar-mode (quasimagnetostatic) magnon oscillations in ferrite particles. Our studies of interactions between microwave electromagnetic fields and small ferrite particles with magnetic-dipolar-mode (MDM) oscillations show strong localization of electromagnetic energy. MDM oscillations in a ferrite disk are at the origin of topological singularities resulting in Poynting vector vortices and symmetry breakings of the microwave near fields. We show that new subwavelength microwave structures can be realized based on a system of interacting MDM ferrite disks. Wave propagation of electromagnetic signals in such structures is characterized by topological phase variations. Interactions of microwave fields with an MDM ferrite disk and MDM-disk arrays open a perspective for creating engineered electromagnetic fields with unique symmetry properties.

Kamenetskii, E. O.; Sigalov, M.; Shavit, R. [Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, IL-84 105 Beer Sheva (Israel)

2010-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Mobile system for microwave removal of concrete surfaces  

DOE Patents [OSTI]

A method and apparatus are disclosed 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. 7 figs.

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

1997-06-03T23:59:59.000Z

362

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

363

Sources of the Radio Background Considered  

SciTech Connect (OSTI)

We investigate possible origins of the extragalactic radio background reported by the ARCADE 2 collaboration. The surface brightness of the background is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low surface brightness regions of radio sources, and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio background is produced by radio point sources that dominate at sub {mu}Jy fluxes. We show that a truly diffuse background produced by elections far from galaxies is ruled out because such energetic electrons would overproduce the observed X-ray/{gamma}-ray background through inverse Compton scattering of the other photon fields. Unrecognized flux from low surface brightness regions of extended radio sources, or moderate flux sources missed entirely by radio source count surveys, cannot explain the bulk of the observed background, but may contribute as much as 10%. We consider both radio supernovae and radio quiet quasars as candidate sources for the background, and show that both fail to produce it at the observed level because of insufficient number of objects and total flux, although radio quiet quasars contribute at the level of at least a few percent. We conclude that the most important population for production of the background is likely ordinary starforming galaxies above redshift 1 characterized by an evolving radio far-infrared correlation, which increases toward the radio loud with redshift.

Singal, J.; /KIPAC, Menlo Park /Stanford U.; Stawarz, L.; /KIPAC, Menlo Park /Stanford U. /Jagiellonian U., Astron. Observ.; Lawrence, A.; /Edinburgh U., Inst. Astron. /KIPAC, Menlo Park /Stanford U.; Petrosian, V.; /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.

2011-08-22T23:59:59.000Z

364

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

E-Print Network [OSTI]

SPIE Conf. Series, Vol. 7741 Battaglia, N. , Bond, J. R. ,The bottom right shows the Battaglia et al. (2010) adiabaticThe second recent model, by Battaglia et al. (2010), is the

Shirokoff, Erik D.

2011-01-01T23:59:59.000Z

365

Microwaves, hyperthermia, and human leukocyte function  

SciTech Connect (OSTI)

The objective of this study is to determine whether exposure to microwaves (2450 MHz) affects the function of human leukocytes in the resting state and during antigenic or mitogenic challenge. This publication is a summary report of the construction and calibration of a waveguide exposure facility for in vitro irradiation of human leukocytes. Calorimetric determinations of specific absorption rates (SAR) were made using heating curves measured with a microwave transparent Vitek 101 Electrothermia Monitor. The correlation between SAR and forward power was highly significant (r=0.95). At a forward power of 0.55 W the average SAR was approximately 33 mW/ml. However, inhomogeneity and significant resonance absorption were noted in the dual vial waveguide exposure facility. A 30-point measurement of SAR distribution revealed that the SAR at any of the measured points could range between 0.12- and 3.94-fold of the average SAR within the given vial. Measurements indicated that this variability in SAR values did not create significant thermal gradients within the vials when external agitation was applied.

Roberts, N.J. Jr; Lu, S.; Michaelson, S.M.

1981-05-01T23:59:59.000Z

366

Pattern formation and propagation during microwave breakdown  

SciTech Connect (OSTI)

During microwave breakdown at atmospheric pressure, a sharp plasma front forms and propagates toward the microwave source at high velocities. Experiments show that the plasma front may exhibit a complex dynamical structure or pattern composed of plasma filaments aligned with the wave electric field and apparently moving toward the source. In this paper, we present a model of the pattern formation and propagation under conditions close to recent experiments. Maxwell's equations are solved together with plasma fluid equations in two dimensions to describe the space and time evolution of the wave field and plasma density. The simulation results are in excellent agreement with the experimental observations. The model provides a physical interpretation of the pattern formation and dynamics in terms of ionization-diffusion and absorption-reflection mechanisms. The simulations allow a good qualitative and quantitative understanding of different features such as plasma front velocity, spacing between filaments, maximum plasma density in the filaments, and influence of the discharge parameters on the development of well-defined filamentary plasma arrays or more diffuse plasma fronts.

Chaudhury, Bhaskar [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Boeuf, Jean-Pierre [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); LAPLACE, CNRS, F-31062 Toulouse (France); Zhu, Guo Qiang [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Northwestern Polytechnique University, Xi'an 710072 (China)

2010-12-15T23:59:59.000Z

367

Stochastic Gravitational Wave Background from Exoplanets  

E-Print Network [OSTI]

Recent exoplanet surveys have predicted a very large population of planetary systems in our galaxy, more than one planet per star on the average, perhaps totalling about two hundred billion. These surveys, based on electro-magnetic observations, are limited to a very small neighbourhood of the solar system and the estimations rely on the observations of only a few thousand planets. On the other hand, orbital motions of planets around stars are expected to emit gravitational waves (GW), which could provide information about the planets not accessible to electro-magnetic astronomy. The cumulative effect of the planets, with periods ranging from few hours to several years, is expected to create a stochastic GW background (SGWB). We compute the characteristic GW strain of this background based on the observed distribution of planet parameters. We also show that the integrated extragalactic background is comparable or less than the galactic background at different frequencies. Our estimate shows that the net backg...

Ain, Anirban; Mitra, Sanjit

2015-01-01T23:59:59.000Z

368

Background and Motivation Biomass derived syngas contains  

E-Print Network [OSTI]

Background and Motivation · Biomass derived syngas contains: CO, H2, small hydrocarbons, H2S prepared by SEA contain smaller metal particle sizes and have higher dispersion · The quantity of reducible

Das, Suman

369

Environmental Permit Application Background Statement (Delaware)  

Broader source: Energy.gov [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...

370

Low background counting techniques at SNOLAB  

SciTech Connect (OSTI)

Many of the experiments currently searching for dark matter, studying properties of neutrinos or searching for neutrinoless double beta decay require very low levels of radioactive backgrounds both in their own construction materials and in the surrounding environment. These low background levels are required so that the experiments can achieve the required sensitivities for their searches. SNOLAB has several facilities which are used to directly measure these radioactive backgrounds. This proceedings will describe SNOLAB's High Purity Germanium Detectors, one of which has been in continuous use for the past seven years measuring materials for many experiments in operation or under construction at SNOLAB. A description of the characterisation of SNOLAB's new germanium well detector will be presented. In addition, brief descriptions of SNOLAB's alpha-beta and electrostatic counters will be presented and a description of SNOLAB's future low background counting laboratory will be given.

Lawson, Ian; Cleveland, Bruce [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)] [SNOLAB, 1039 Regional Rd 24, Lively, ON P3Y 1N2 (Canada)

2013-08-08T23:59:59.000Z

371

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

1999-01-01T23:59:59.000Z

372

Background Assay and Rejection in DRIFT  

E-Print Network [OSTI]

The DRIFT-IId dark matter detector is a m$^3$-scale low-pressure TPC with directional sensitivity to WIMP-induced nuclear recoils. Its primary backgrounds were due to alpha decays from contamination on the central cathode. Efforts to reduce these backgrounds led to replacing the 20 \\mu m wire central cathode with one constructed from 0.9 \\mu m aluminized mylar, which is almost totally transparent to alpha particles. Detailed modeling of the nature and origin of the remaining backgrounds led to an in-situ, ppt-sensitive assay of alpha decay backgrounds from the central cathode. This led to further improvements in the thin-film cathode resulting in over 2 orders of magnitude reduction in backgrounds compared to the wire cathode. Finally, the addition of O$_2$ to CS$_2$ gas was found to produce multiple species of electronegative charge carriers, providing a method to determine the absolute position of nuclear recoils and reject all known remaining backgrounds while retaining a high efficiency for nuclear recoil detection.

Jeff Brack; Ed Daw; Alexei Dorofeev; Anthony Ezeribe; Jean-Luc Gauvreau; Michael Gold; John Harton; Randy Lafler; Robert Lauer; Eric R. Lee; Dinesh Loomba; John Matthews; Eric H. Miller; Alissa Monte; Alex Murphy; Sean Paling; Nguyen Phan; Steve Sadler; Andrew Scarff; Daniel Snowden-Ifft; Neil Spooner; Sam Telfer; Daniel Walker; Matt Williams; Leonid Yuriev

2014-04-08T23:59:59.000Z

373

ARM: Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

Cadeddu, Maria

374

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

375

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

376

Gamma-Ray Bursts, Ultra High Energy Cosmic Rays, and Cosmic Gamma-Ray Background  

E-Print Network [OSTI]

We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs, and this large energy can be radiated in TeV range by synchrotron radiation of ultra-high-energy protons (\\sim 10^{20} eV). The possible detection of GRBs above 10 TeV suggested by the Tibet and HEGRA groups also supports this idea. If this is the case, most of TeV gamma-rays from GRBs are absorbed in intergalactic fields and eventually form GeV gamma-ray background, whose flux is in good agreement with the recent observation.

Tomonori Totani

1999-04-13T23:59:59.000Z

377

Radiation receiver  

DOE Patents [OSTI]

The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

Hunt, A.J.

1983-09-13T23:59:59.000Z

378

Radiation receiver  

DOE Patents [OSTI]

The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

Hunt, Arlon J. (Oakland, CA)

1983-01-01T23:59:59.000Z

379

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

380

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. 6 figures.

Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

1995-01-24T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Design of a novel Cherenkov detectors system for machine induced background monitoring in the CMS cavern  

E-Print Network [OSTI]

A novel detector system has been designed for an efficient online measurement of the machineinduced background in the CMS experimental cavern. The suppression of the CMS cavern background originating from pp collision products and the 25 ns bunch spacing have set the requirements for the detector design. Each detector unit will be a radiation hard, cylindrical Cherenkov radiator optically coupled to an ultra-fast UV-sensitive photomultiplier tube, providing a prompt, directionally sensitive measurement. Simulation and test beam measurements have shown the achievability of the goals that have driven the baseline design. The system will consist of 20 azimuthally distributed detectors per end, installed at a radius of r ~ 180 cm and a distance 20.6 m away from the CMS interaction region. The detector units will enable a measurement of the transverse distribution of the bunchby- bunch machine induced background flux. This will provide important feedback from the CMS on the beam conditions during the LHC machine s...

Orfanelli, Styliani; Giunta, Marina; Stickland, David P; Ambrose, Mitchell J; Rusack, Roger; Finkel, Alexey

2013-01-01T23:59:59.000Z

382

Background-reducing X-ray multilayer mirror  

DOE Patents [OSTI]

Background-reducing x-ray multilayer mirror. A multiple-layer "wavetrap" deposited over the surface of a layered, synthetic-microstructure soft x-ray mirror optimized for reflectivity at chosen wavelengths is disclosed for reducing the reflectivity of undesired, longer wavelength incident radiation incident thereon. In three separate mirror designs employing an alternating molybdenum and silicon layered, mirrored structure overlaid by two layers of a molybdenum/silicon pair anti-reflection coating, reflectivities of near normal incidence 133, 171, and 186 .ANG. wavelengths have been optimized, while that at 304 .ANG. has been minimized. The optimization process involves the choice of materials, the composition of the layer/pairs as well as the number thereof, and the distance therebetween for the mirror, and the simultaneous choice of materials, the composition of the layer/pairs, and their number and distance for the "wavetrap."

Bloch, Jeffrey J. (Los Alamos, NM); Roussel-Dupre', Diane (Los Alamos, NM); Smith, Barham W. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

383

Cosmological Consequences of Classical Flavor-Space Locked Gauge Field Radiation  

E-Print Network [OSTI]

We propose a classical SU(2) gauge field in a flavor-space locked configuration as a species of radiation in the early universe, and show that it would have a significant imprint on a primordial stochastic gravitational wave spectrum. In the flavor-space locked configuration, the electric and magnetic fields of each flavor are parallel and mutually orthogonal to other flavors, with isotropic and homogeneous stress-energy. Due to the non-Abelian coupling, the gauge field breaks the symmetry between left- and right-circularly polarized gravitational waves. This broken chiral symmetry results in a unique signal: non-zero cross correlation of the cosmic microwave background temperature and polarization, $TB$ and $EB$, both of which should be zero in the standard, chiral symmetric case. We forecast the ability of current and future CMB experiments to constrain this model. Furthermore, a wide range of behavior is shown to emerge, depending on the gauge field coupling, abundance, and allocation into electric and magnetic field energy density. The fluctuation power of primordial gravitational waves oscillates back and forth into fluctuations of the gauge field. In certain cases, the gravitational wave spectrum is shown to be suppressed or amplified by up to an order of magnitude depending on the initial conditions of the gauge field.

Jannis Bielefeld; Robert R. Caldwell

2015-03-17T23:59:59.000Z

384

Cosmological Consequences of Classical Flavor-Space Locked Gauge Field Radiation  

E-Print Network [OSTI]

We propose a classical SU(2) gauge field in a flavor-space locked configuration as a species of radiation in the early universe, and show that it would have a significant imprint on a primordial stochastic gravitational wave spectrum. In the flavor-space locked configuration, the electric and magnetic fields of each flavor are parallel and mutually orthogonal to other flavors, with isotropic and homogeneous stress-energy. Due to the non-Abelian coupling, the gauge field breaks the symmetry between left- and right-circularly polarized gravitational waves. This broken chiral symmetry results in a unique signal: non-zero cross correlation of the cosmic microwave background temperature and polarization, $TB$ and $EB$, both of which should be zero in the standard, chiral symmetric case. We forecast the ability of current and future CMB experiments to constrain this model. Furthermore, a wide range of behavior is shown to emerge, depending on the gauge field coupling, abundance, and allocation into electric and mag...

Bielefeld, Jannis

2015-01-01T23:59:59.000Z

385

Prediction of the Virgo axis anisotropy: CMB radiation illuminates the nature of things  

E-Print Network [OSTI]

Recent findings of the anisotropy in the Cosmic Microwave Background (CMB) radiation are confusing for standard cosmology. Remarkably, this fact has been predicted several years ago in the framework of our model of the physical world. Moreover, in exact agreement with our prediction the CMB has a preferred direction towards the Virgo Cluster. The transpired structure of the CMB shows workings of the suggested model of the physical world. Comprising the information processes of Nature, this model presents a high-tech version of the previous low-tech developments for mechanical ether and quantum vacuum. In the current model, the phenomenon of Life turns up as a collective effect on the "Internet of the Physical Universe" using DNA structures for access codes. Most convincingly, this construction points to a harmful analogy with so-called "identity theft" - improper manipulations with DNA of individual organisms can destroy these organisms from a remote location without any physical contact. Appearing incredible, such a possibility creates a superlative Experimentum Crucis. In a broad sense, this surmised biological effect is intimately related to the cosmological prediction of the structurization of the CMB, but it is more compelling.

Simon Berkovich

2005-09-25T23:59:59.000Z

386

Electrical detection of microwave assisted magnetization reversal by spin pumping  

SciTech Connect (OSTI)

Microwave assisted magnetization reversal has been investigated in a bilayer system of Pt/ferromagnet by detecting a change in the polarity of the spin pumping signal. The reversal process is studied in two material systems, Pt/CoFeB and Pt/NiFe, for different aspect ratios. The onset of the switching behavior is indicated by a sharp transition in the spin pumping voltage. At a threshold value of the external field, the switching process changes from partial to full reversal with increasing microwave power. The proposed method provides a simple way to detect microwave assisted magnetization reversal.

Rao, Siddharth; Subhra Mukherjee, Sankha; Elyasi, Mehrdad; Singh Bhatia, Charanjit; Yang, Hyunsoo, E-mail: eleyang@nus.edu.sg [Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, Singapore 117576 (Singapore)

2014-03-24T23:59:59.000Z

387

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

388

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

SciTech Connect (OSTI)

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

389

NEW SOURCES OF RADIATION  

E-Print Network [OSTI]

Stanford Synchrotron Radiation Project Report No. 75/07.IBL 79M0733 Fig. 20. Radiation emission pattern by electronsWinick, Stanford Synchrotron Radiation Laboratory. Fig. 21.

Schimmerling, W.

2010-01-01T23:59:59.000Z

390

Radiation-induced angiosarcoma  

E-Print Network [OSTI]

1a Figure 1b Figure 1. Radiation-induced angiosarcoma in afollowing completion of radiation therapy. Figure 2a Figurecell histiocytosis after radiation for breast carcinoma: can

Anzalone, C Lane; Cohen, Philip R; Diwan, Abdul H; Prieto, Victor G

2013-01-01T23:59:59.000Z

391

Radiation Protection Act (Pennsylvania)  

Broader source: Energy.gov [DOE]

This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...

392

2D microwave imaging reflectometer electronics  

SciTech Connect (OSTI)

A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

Spear, A. G.; Domier, C. W., E-mail: cwdomier@ucdavis.edu; Hu, X.; Muscatello, C. M.; Ren, X.; Luhmann, N. C. [Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-11-15T23:59:59.000Z

393

Quantum chaotic scattering in microwave resonators  

SciTech Connect (OSTI)

In a frequency range where a microwave resonator simulates a chaotic quantum billiard, we have measured moduli and phases of reflection and transmission amplitudes in the regimes of both isolated and of weakly overlapping resonances and for resonators with and without time-reversal invariance. Statistical measures for S-matrix fluctuations were determined from the data and compared with extant and/or newly derived theoretical results obtained from the random-matrix approach to quantum chaotic scattering. The latter contained a small number of fit parameters. The large data sets taken made it possible to test the theoretical expressions with unprecedented accuracy. The theory is confirmed by both a goodness-of-fit-test and the agreement of predicted values for those statistical measures that were not used for the fits, with the data.

Dietz, B.; Miski-Oglu, M.; Schaefer, F. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Friedrich, T. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); GSI Helmholzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Harney, H. L.; Weidenmueller, H. A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Richter, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); ECT, Villa Tambosi, I-38100 Villazzano (Trento) (Italy)

2010-03-15T23:59:59.000Z

394

Compact microwave ion source for industrial applications  

SciTech Connect (OSTI)

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

395

Background modeling for the GERDA experiment  

SciTech Connect (OSTI)

The neutrinoless double beta (0???) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0??? decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ??} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and ? emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

Becerici-Schmidt, N. [Max-Planck-Institut für Physik, München (Germany)] [Max-Planck-Institut für Physik, München (Germany); Collaboration: GERDA Collaboration

2013-08-08T23:59:59.000Z

396

Microwave-Regenerated Diesel Exhaust Particulate Filter  

SciTech Connect (OSTI)

Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

Nixdorf, Richard D. (Industrial Ceramic Solution, LLC); Green, Johney Boyd; Story, John M.; Wagner, Robert M. (Oak Ridge National Laboratory)

2001-03-05T23:59:59.000Z

397

Optical emission line monitor with background observation and cancellation  

DOE Patents [OSTI]

A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.

Goff, David R. (Star City, WV); Notestein, John E. (Morgantown, WV)

1986-01-01T23:59:59.000Z

398

Optical emission line monitor with background observation and cancellation  

DOE Patents [OSTI]

A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interfering blackbody radiation by greater than 20 dB.

Goff, D.R.; Notestein, J.E.

1985-01-04T23:59:59.000Z

399

Validation and analysis of microwave-derived rainfall over the tropics. Master's thesis  

SciTech Connect (OSTI)

A recently developed single channel microwave rain rate retrieval algorithm exists to measure global precipitation over the data-sparse tropical oceans. The objective of this study is to retrieve and validate rainfall using this algorithm, followed by an analysis of the derived rainfall fields. Retrieval consists of applying the algorithm technique to the extraction of four years worth of achieved data from the Electrically Scanning Microwave Radiometer (ESMR) instrument flown aboard the NIMBUS 5 satellite. The Pacific Atoll Raingage Data Set is chosen as a ground truth measure to validate the ESMR-Derived rainfall data against, comparing slope, intercept and correlation between 5 deg x 5 deg area average. Despite limitations imposed by the comparison of point measurements to area-averaged rainfall, results show a 0.80 correlation. Monthly and quarterly climatological mean rainfall estimates are produced, with a consequent analysis of prominent signals, especially in the Intertropical Convergence Zone (ITCZ), South Pacific Convergence Zone (SPCZ) and the Indian monsoon. Latent heat flux is computed, using the ESMR-derived rainfall, and plotted to show qualitatively where seasonal latent thermodynamic energy sources and sinks exist in the atmosphere. A comparison of the summer and winter quarterly composites of the above products with previously compiled climatologies and Outgoing Longwave Radiation (OLR) showed only minor discrepancies in location and intensity, which are discussed in some detail.

Fleishauer, R.P.

1993-01-01T23:59:59.000Z

400

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

Note: This page contains sample records for the topic "microwave background radiation" 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

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

402

Slotted Ground Structures and Their Applications to Various Microwave Components  

E-Print Network [OSTI]

(LPF) using slotted ground structure (SGS) with dumbbell shape is designed and measured to validate its theories. By using SGS techniques presented in this thesis, some other RF/microwave components such as a periodic structure, ultra-wideband bandpass...

Jung, Dong

2010-01-16T23:59:59.000Z

403

Temperature Modeling for Reaction Development in Microwave-Assisted Chemistry  

E-Print Network [OSTI]

made to evaluate and classify the effects of microwave irradiation. While it is commonly acknowledged energy, such as materials processing and food technologies, one can observe an expanding use

Yakovlev, Vadim

404

Analytical scanning evanescent microwave microscope and control stage  

DOE Patents [OSTI]

A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

2013-01-22T23:59:59.000Z

405

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

406

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

407

Background field method and nonrelativistic QED matching  

E-Print Network [OSTI]

We discuss the resolution of an inconsistency between lattice background field methods and nonrelativistic QED matching conditions. In particular, we show that lack of on-shell conditions in lattice QCD with time-dependent background fields generally requires that certain operators related by equations of motion should be retained in an effective field theory to correctly describe the behavior of Green's functions. The coefficients of such operators in a nonrelativistic hadronic theory are determined by performing a robust nonrelativistic expansion of QED for relativistic scalar and spin-half hadrons including nonminimal electromagnetic couplings. Provided that nonrelativistic QED is augmented with equation-of-motion operators, we find that the background field method can be reconciled with the nonrelativistic QED matching conditions without any inconsistency. We further investigate whether nonrelativistic QED can be employed in the analysis of lattice QCD correlation function in background fields, but we are confronted with difficulties. Instead, we argue that the most desirable approach is a hybrid one which relies on a relativistic hadronic theory with operators chosen based on their relevance in the nonrelativistic limit. Using this hybrid framework, we obtain practically useful forms of correlation functions for scalar and spin-half hadrons in uniform electric and magnetic fields.

Jong-Wan Lee; Brian C. Tiburzi

2014-11-15T23:59:59.000Z

408

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.

409

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.

410

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

411

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

412

Perturbations of supertube in KK monopole background  

E-Print Network [OSTI]

We study perturbations of supertube in KK monopole background, at both DBI and supergravity levels. We analyse both NS1-P as well as D0-F1 duality frames and study different profiles. This illuminates certain aspects of bound states of KK monopoles with supertubes.

Yogesh K. Srivastava

2006-11-29T23:59:59.000Z

413

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"

414

2013 National Geothermal Student Competition Background  

E-Print Network [OSTI]

1 2013 National Geothermal Student Competition Background: The 2013 National Geothermal Student, is designed to advance the understanding of geothermal energy as a valued resource by promoting innovation to engage students in a collaborative exercise to develop a business plan for developing a geothermal

Carrington, Emily

415

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

416

Microwave mode shifting antenna system for regenerating particulate filters  

DOE Patents [OSTI]

A regeneration system comprises a particulate matter (PM) filter including a microwave energy absorbing surface, and an antenna system comprising N antennas and an antenna driver module that sequentially drives the antenna system in a plurality of transverse modes of the antenna system to heat selected portions of the microwave absorbing surface to regenerate the PM filter, where N is an integer greater than one. The transverse modes may include transverse electric (TE) and/or transverse magnetic (TM) modes.

Gonze, Eugene V [Pinckney, MI; Kirby, Kevin W [Calabasas Hills, CA; Phelps, Amanda [Malibu, CA; Gregoire, Daniel J [Thousand Oaks, CA

2011-04-26T23:59:59.000Z

417

Mathematical and experimental modelling of heat pump assisted microwave drying  

SciTech Connect (OSTI)

Drying is one of the most energy intensive operations in industry and agriculture. In the quest to increase drying efficiency and product quality, new technologies and methods are constantly being sought. Of these technologies, heat pump assisted drying and microwave drying have proved to be the most promising contenders. In order to achieve a better understanding and provide a computer design tool for heat pump assisted convective and microwave drying, both mathematical modelling and experimental investigations of heat pump assisted microwave dryers have been undertaken in this study. A mathematical model has been developed to predict the steady-state performance of a heat pump assisted continuous microwave dryer, with emphasis on the simulation of heat and mass transfer processes in the evaporator and drying chamber. The model is intend to serve as a design tool in the study of heat pump dryers. To achieve the optimum design, the influences of the key design and operating parameters, as well as the comparison of different drying configurations, have been examined. Based on investigation results, several methods have been proposed to improve the performance of heat pump assisted microwave drying, such as the use of a recuperator. To validate the above mathematical model, extensive drying tests using foam rubber as the test material have been conducted on a prototype heat pump assisted microwave dryer. The prototype heat pump input power was 5 kW with a maximum microwave input power of 10 kW. The experimental performance data confirmed the veracity of the simulation model. The experimental results on drying test materials indicate that with careful design heat pump assisted microwave drying is comparable to convective drying in energy consumption while with a much higher drying speed.

Xiguo Jia (Univ. of Queensland (Australia))

1993-01-01T23:59:59.000Z

418

Proposal for an Optomechanical Microwave Sensor at the Subphoton Level  

E-Print Network [OSTI]

Because of 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

2015-03-17T23:59:59.000Z

419

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

420

Injection locking of laser diodes for microwave signal generation  

E-Print Network [OSTI]

INJECTION LOCKING OF LASER DIODES FOR MICROWAVE SIGNAL GENERATION A Thesis by BEN-MOU YU Submitted to the Graduate College of Texas ARM University in partial fulfillment. of the requirement. for the degree of MASTER OF SCIENCE August 1987... Major Subject: Electrical Engineering INJECTION LOCKING OF LASER DIODES FOR MICROWAVE SIGNAL GENERATION A Thesis BEN. -MOU YU Approved as to style and content by: Taylor, Henry . (E. E. ) (Chairman of Committee) Chang, Kai (E. E. ) (Member) 0...

Yu, Ben-Mou

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Fuel gas production by microwave plasma in liquid  

SciTech Connect (OSTI)

We propose to apply plasma in liquid to replace gas-phase plasma because we expect much higher reaction rates for the chemical deposition of plasma in liquid than for chemical vapor deposition. A reactor for producing microwave plasma in a liquid could produce plasma in hydrocarbon liquids and waste oils. Generated gases consist of up to 81% hydrogen by volume. We confirmed that fuel gases such as methane and ethylene can be produced by microwave plasma in liquid.

Nomura, Shinfuku; Toyota, Hiromichi; Tawara, Michinaga; Yamashita, Hiroshi; Matsumoto, Kenya [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan); Shikoku Industry and Technology Promotion Center, 2-5 Marunouchi, Takamatsu, Kagawa 760-0033 (Japan)

2006-06-05T23:59:59.000Z

422

Radiation of a neutral polarizable particle moving uniformly through a thermal radiation field  

E-Print Network [OSTI]

We discuss the properties of thermal electromagnetic radiation produced by a neutral polarizable nanoparticle moving with an arbitrary relativistic velocity in a heated vacuum background with a fixed temperature. We show that the particle in its own rest frame acquires the radiation temperature of vacuum, multiplied by a velocity-dependent factor, and then emits thermal photons predominantly in the forward direction. The intensity of radiation proves to be much higher than for the particle at rest. For metal particles with high energy, the ratio of emitted and absorbed radiation power is proportional to the Lorentz-factor squared.

G. V. Dedkov; A. A. Kyasov

2014-06-25T23:59:59.000Z

423

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

424

Microwave processing of ceramic oxide filaments. Annual report, FY1997  

SciTech Connect (OSTI)

The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company. Continuous ceramic filaments are a principal component in many advanced high temperature materials like continuous fiber ceramic composites (CFCC) and woven ceramic textiles. The use of continuous ceramic filaments in CFCC radiant burners, gas turbines, waste incineration, and hot gas filters in U.S. industry and power generation is estimated to save at least 2.16 quad/yr by year 2010 with energy cost savings of at least $8.1 billion. By year 2010, continuous ceramic filaments and CFCC`s have the potential to abate pollution emissions by 917,000 tons annually of nitrous oxide and 118 million tons annually of carbon dioxide (DOE Report OR-2002, February, 1994).

Vogt, G.J.

1998-12-31T23:59:59.000Z

425

Estimations of local thermal impact on living organisms irradiated by non-thermal microwaves  

E-Print Network [OSTI]

Pennes' differential equation for bioheat transfer and the heat transfer equation are solved for the temperature distribution in a living tissue with spherical inclusions, irradiated by microwave power. It is shown that relative temperature excess in a small inclusion in the tissue in some cases is inversely proportional to its radius and does not depend on the applied power. In pulsing RF fields the effect is amplified proportionally to the ratio of the pulse period to the pulse duration. The local temperature rise significantly outpaces the averaged one and therefore the Watt to Weight SAR limits may be insufficient to estimate the safety of RF radiation and the conventional division of the biological effects of electromagnetic fields on the thermal and non-thermal needs to be revised.

Shatalov, Vladimir

2013-01-01T23:59:59.000Z

426

An upper bound from helioseismology on the stochastic background of gravitational waves  

E-Print Network [OSTI]

The universe is expected to be permeated by a stochastic background of gravitational radiation of astrophysical and cosmological origin. This background is capable of exciting oscillations in solar-like stars. Here we show that solar-like oscillators can be employed as giant hydrodynamical detectors for such a background in the muHz to mHz frequency range, which has remained essentially unexplored until today. We demonstrate this approach by using high-precision radial velocity data for the Sun to constrain the normalized energy density of the stochastic gravitational-wave background around 0.11 mHz. These results open up the possibility for asteroseismic missions like CoRoT and Kepler to probe fundamental physics.

Daniel M. Siegel; Markus Roth

2014-03-28T23:59:59.000Z

427

Properties of Natural Radiation and Radioactivity  

SciTech Connect (OSTI)

Ubiquitous natural sources of radiation and radioactive material (naturally occurring radioactive material, NORM) have exposed humans throughout history. To these natural sources have been added technologically-enhanced naturally occurring radioactive material (TENORM) sources and human-made (anthropogenic) sources. This chapter describes the ubiquitous radiation sources that we call background, including primordial radionuclides such as 40K, 87Rb, the 232Th series, the 238U series, and the 235U series; cosmogenic radionuclides such as 3H and 14C; anthropogenic radionuclides such as 3H, 14C, 137Cs, 90Sr, and 129I; radiation from space; and radiation from technologically-enhanced concentrations of natural radionuclides, particularly the short-lived decay products of 222Rn ("radon") and 220Rn ("thoron") in indoor air. These sources produce radiation doses to people principally via external irradiation or internal irradiation following intakes by inhalation or ingestion. The effective doses from each are given, with a total of 3.11 mSv y-1 (311 mrem y-1) to the average US resident. Over 2.5 million US residents receive over 20 mSv y-1 (2 rem y-1), primarily due to indoor radon. Exposure to radiation from NORM and TENORM produces the largest fraction of ubiquitous background exposure to US residents, on the order of 2.78 mSv (278 mrem) or about 89%. This is roughly 45% of the average annual effective dose to a US resident of 6.2 mSv y-1 (620 mrem y-1) that includes medical (48%), consumer products and air travel (2%), and occupational and industrial (0.1%). Much of this chapter is based on National Council on Radiation Protection and Measurements (NCRP) Report No. 160, "Ionizing Radiation Exposure of the Population of the United States," for which the author chaired the subcommittee that wrote Chapter 3 on "Ubiquitous Background Radiation."

Strom, Daniel J.

2009-07-13T23:59:59.000Z

428

Foreign Energy Company Competitiveness: Background information  

SciTech Connect (OSTI)

This report provides background information to the report Energy Company Competitiveness: Little to Do With Subsidies (DOE 1994). The main body of this publication consists of data uncovered during the course of research on this DOE report. This data pertains to major government energy policies in each country studied. This report also provides a summary of the DOE report. In October 1993, the Office of Energy Intelligence, US Department of Energy (formerly the Office of Foreign Intelligence), requested that Pacific Northwest Laboratory prepare a report addressing policies and actions used by foreign governments to enhance the competitiveness of their energy firms. Pacific Northwest Laboratory prepared the report Energy Company Competitiveness Little to Do With Subsidies (DOE 1994), which provided the analysis requested by DOE. An appendix was also prepared, which provided extensive background documentation to the analysis. Because of the length of the appendix, Pacific Northwest Laboratory decided to publish this information separately, as contained in this report.

Weimar, M.R.; Freund, K.A.; Roop, J.M.

1994-10-01T23:59:59.000Z

429

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

430

Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds  

SciTech Connect (OSTI)

The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

Westwater, Edgeworth

2011-05-06T23:59:59.000Z

431

A background free double beta decay experiment  

E-Print Network [OSTI]

We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.

Ioannis Giomataris

2010-12-20T23:59:59.000Z

432

Radiative heat transfer between dielectric bodies  

E-Print Network [OSTI]

The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.

Svend-Age Biehs

2011-03-16T23:59:59.000Z

433

Alpha Radiation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICE OF RESEARCHThermal SolarAllocatioBasics of Radiation Gamma

434

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

435

UNIVERSITY of CALIFORNIA MICROWAVE ABSORPTION IN NANOSTRUCTURES  

E-Print Network [OSTI]

-magnetic interference and materials that provide cheap and effective shielding from the unwanted radiation. In aerospace is an essential part of the stealth technology where it is used to minimize the reflection of a radar beam from A Data Formatting 28 B Material Analysis 31 Bibliography 39 #12;v List of Figures 2.1 Boundary components

Belanger, David P.

436

APPLICATION OF MICROWAVE-ASSISTED PHOTOCHEMISTRY  

E-Print Network [OSTI]

2, 611 37 Brno, Czech Republic Institute of Chemical Process Fundamentals, Academy of Sciences in friction with neighboring molec ules and thereby in heat. On the other hand, the UV-VIS radiation can bring pollutants - see similarities between the solar spectrum and the spectrum of sulfur EDL). w w w w w w

Cirkva, Vladimir

437

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

SciTech Connect (OSTI)

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

438

An Assessment of Microwave Absorption Models and Retrievals of Cloud Liquid Water Using Clear-Sky Data  

SciTech Connect (OSTI)

Passive microwave radiometers have a long history in the remote sensing of atmospheric liquid and water vapor. Retrievals of these quantities are sensitive to variations in pressure and temperature of the liquid and water vapor. Rather than use a statistical or climatological approach to account for the natural variability in atmospheric pressure and temperature, additional information on the atmospheric profile at the time of the radiometer measurements can be directly incorporated into the retrieval process. Such an approach has been referred to in the literature as a “physical-iterative” solution. This paper presents an assessment of the accuracy of the column liquid water path that can be expected using such an iterative technique as a result of uncertainties in the microwave emissions from oxygen and water vapor. It is shown that the retrieval accuracy is influenced by the accuracy of the instrument measurements and the quality of the atmospheric profiles of temperature and pressure, as one would expect. But also critical is the uncertainty in the absorption coefficients used in the underlying microwave radiative transfer model. The uncertainty in the absorption coefficients is particularly problematic in that it may well bias the liquid water retrieval. The differences between 3 absorption models examined in this paper are equivalent to a bias of 15 to 30 g/m2, depending on the total column water vapor. An examination of typical liquid water paths from the Southern Great Plains region of the United States shows that errors of this magnitude have significant implications for shortwave radiation and retrievals of cloud effective particle size.

Marchand, Roger T.; Ackerman, Thomas P.; Westwater, Ed R.; Clough, Shepard A.; Cady-Pereira, Karen; Liljegren, James C.

2003-12-19T23:59:59.000Z

439

Cellular telephone-based wide-area radiation detection network  

DOE Patents [OSTI]

A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

Craig, William W. (Pittsburg, CA); Labov, Simon E. (Berkeley, CA)

2009-06-09T23:59:59.000Z

440

Superconducting Hair on Charged Black String Background  

E-Print Network [OSTI]

Behaviour of Dirac fermions in the background of a charged black string penetrated by an Abelian Higgs vortex is elaborated. One finds the evidence that the system under consideration can support fermion fields acting like a superconducting cosmic string in the sence that a nontrivial Dirac fermion field can be carried by the system in question. The case of nonextremal and extremal black string vortex systems were considered. The influence of electric and Higgs charge, the winding number and the fermion mass on the fermion localization near the black string event horizon was studied. It turned out that the extreme charged black string expelled fermion fields more violently comparing to the nonextremal one.

Lukasz Nakonieczny; Marek Rogatko

2012-01-25T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Adaptors for radiation detectors  

DOE Patents [OSTI]

Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

Livesay, Ronald Jason

2014-04-22T23:59:59.000Z

442

Microwave-Assisted Synthesis of II-VI Semiconductor Micro- and Nanoparticles towards Sensor Applications  

E-Print Network [OSTI]

leads to slow heating and allows decomposition of reagents or products over time. Microwave-assisted heating provides faster, localized heating at the molecular level with near instantaneous control over reaction parameters. In this work, microwave...

Majithia, Ravish

2013-01-15T23:59:59.000Z

443

be virtually impossible to construct land lines and microwave networks in the  

E-Print Network [OSTI]

) with a microwave radio transmission tail is not suit- able for very harsh terrain, or for locations that are more. The use of microwave repeater towers, requiring line- of-sight from one tower to the next, was ruled out

Brewer, Eric A.

444

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

445

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

446

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

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

447

Letter to the Editor Microwave assisted exfoliation and reduction of graphite  

E-Print Network [OSTI]

Letter to the Editor Microwave assisted exfoliation and reduction of graphite oxide yet versatile method to simultaneously achieve the exfoliation and reduction of graphite oxide of crumpled, few-layer thick and electronically conductive graphitic sheets. Using the microwave exfoliated

448

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

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

449

A background free double beta decay experiment  

E-Print Network [OSTI]

We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a te...

Giomataris, Ioannis

2010-01-01T23:59:59.000Z

450

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.

451

One piece microwave container screens for electrodeless lamps  

DOE Patents [OSTI]

A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. Replacing mesh material by solid metal material as part of the screen unit significantly reduces leakage of microwave energy from the lamp. The solid section has multiple compliant fingers defined therein for engaging the periphery of a flange on the waveguide unit so that a hose clamp can easily secure the screen to the assembly. Screen units of this type having different mesh section configurations can be interchanged in the lamp assembly to produce different respective illumination patterns.

Turner, Brian (Myersville, MD); Ury, Michael (Bethesda, MD)

1998-01-01T23:59:59.000Z

452

Spectral properties of microwave graphs with local absorption  

E-Print Network [OSTI]

The influence of absorption on the spectra of microwave graphs has been studied experimentally. The microwave networks were made up of coaxial cables and T junctions. First, absorption was introduced by attaching a 50 Ohm load to an additional vertex for graphs with and without time-reversal symmetry. The resulting level-spacing distributions were compared with a generalization of the Wigner surmise in the presence of open channels proposed recently by Poli et al. [Phys. Rev. Lett. 108, 174101 (2012)]. Good agreement was found using an effective coupling parameter. Second, absorption was introduced along one individual bond via a variable microwave attenuator, and the influence of absorption on the length spectrum was studied. The peak heights in the length spectra corresponding to orbits avoiding the absorber were found to be independent of the attenuation, whereas, the heights of the peaks belonging to orbits passing the absorber once or twice showed the expected decrease with increasing attenuation.

M. Allgaier; S. Gehler; S. Barkhofen; H. -J. Stöckmann; U. Kuhl

2014-03-30T23:59:59.000Z

453

RADIATION SAFETY OFFICE UNIVERSITYOF MARYLAND  

E-Print Network [OSTI]

RADIATION SAFETY OFFICE UNIVERSITYOF MARYLAND RADIATION SAFETY MANUAL UNIVERSITY OF MARYLAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2. Radiation Safety Committee (RSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.4. Radiation Safety Office (RSO

Rubloff, Gary W.

454

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

455

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

456

Sub-wavelength resonant structures at microwave and optical frequencies  

E-Print Network [OSTI]

x axis, while the electric dipole has a radiation null alongloop) and the electric dipole (across the small z Radiationelectric dipole constructively contribute to the total radiation

Simi?, Aleksandar

2011-01-01T23:59:59.000Z

457

The White Dwarf -- White Dwarf galactic background in the LISA data  

E-Print Network [OSTI]

LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low-part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. Since the galactic white-dwarfs background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of one year, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarfs binary systems present in our Galaxy.

Jeffrey A. Edlund; Massimo Tinto; Andrzej Krolak; Gijs Nelemans

2005-04-22T23:59:59.000Z

458

Gabriele Simi1 BaBar SVT: Radiation Damage and BaBar SVT: Radiation Damage and  

E-Print Network [OSTI]

-shelled into place after installation of B1 magnets Radiation exposure at innermost layer (nominal background level was originally designed to function in up to 10 X nominal background. #12;Gabriele Simi5 DesignDesign Double sided nbulk silcon sensors, 630 k cm Custom frontend chips (honeywell 0.8 m) Arch shaped outer layer

California at Santa Cruz, University of

459

Gravitational wave background from Standard Model physics: Qualitative features  

E-Print Network [OSTI]

Because of physical processes ranging from microscopic particle collisions to macroscopic hydrodynamic fluctuations, any plasma in thermal equilibrium emits gravitational waves. For the largest wavelengths the emission rate is proportional to the shear viscosity of the plasma. In the Standard Model at T > 160 GeV, the shear viscosity is dominated by the most weakly interacting particles, right-handed leptons, and is relatively large. We estimate the order of magnitude of the corresponding spectrum of gravitational waves. Even though at small frequencies (corresponding to the sub-Hz range relevant for planned observatories such as eLISA) this background is tiny compared with that from non-equilibrium sources, the total energy carried by the high-frequency part of the spectrum is non-negligible if the production continues for a long time. We suggest that this may constrain (weakly) the highest temperature of the radiation epoch. Observing the high-frequency part directly sets a very ambitious goal for future ge...

Ghiglieri, J

2015-01-01T23:59:59.000Z

460

Project Lyman: Quantifying 11 Gyrs of Metagalactic Ionizing Background Evolution  

E-Print Network [OSTI]

The timing and duration of the reionization epoch is crucial to the emergence and evolution of structure in the universe. The relative roles that star-forming galaxies, active galactic nuclei and quasars play in contributing to the metagalactic ionizing background across cosmic time remains uncertain. Deep quasar counts provide insights into their role, but the potentially crucial contribution from star-formation is highly uncertain due to our poor understanding of the processes that allow ionizing radiation to escape into the intergalactic medium (IGM). The fraction of ionizing photons that escape from star-forming galaxies is a fundamental free parameter used in models to "fine-tune" the timing and duration of the reionization epoch that occurred somewhere between 13.4 and 12.7 Gyrs ago (redshifts between 12 > z > 6). However, direct observation of Lyman continuum (LyC) photons emitted below the rest frame \\ion{H}{1} ionization edge at 912 \\AA\\ is increasingly improbable at redshifts z > 3, due to the stead...

McCandliss, Stephan R; Bergvall, Nils; Bianchi, Luciana; Bridge, Carrie; Bogosavljevic, Milan; Cohen, Seth H; Deharveng, Jean-Michel; Dixon, W Van Dyke; Ferguson, Harry; Friedman, Peter; Hayes, Matthew; Howk, J Christopher; Inoue, Akio; Iwata, Ikuru; Kaiser, Mary Elizabeth; Kriss, Gerard; Kruk, Jeffrey; Kutyrev, Alexander S; Leitherer, Claus; Meurer, Gerhardt R; Prochaska, Jason X; Sonneborn, George; Stiavelli, Massimo; Teplitz, Harry I; Windhorst, Rogier A

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "microwave background radiation" 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

Dusty Infrared Galaxies: Sources of the Cosmic Infrared Background  

E-Print Network [OSTI]

The discovery of the Cosmic Infrared Background (CIB) in 1996, together with recent cosmological surveys from the mid-infrared to the millimeter have revolutionized our view of star formation at high redshifts. It has become clear, in the last decade, that a population of galaxies that radiate most of their power in the far-infrared (the so-called ``infrared galaxies'') contributes an important part of the whole galaxy build-up in the Universe. Since 1996, detailed (and often painful) investigations of the high-redshift infrared galaxies have resulted in the spectacular progress covered in this review. We outline the nature of the sources of the CIB including their star-formation rate, stellar and total mass, morphology, metallicity and clustering properties. We discuss their contribution to the stellar content of the Universe and their origin in the framework of the hierarchical growth of structures. We finally discuss open questions for a scenario of their evolution up to the present-day galaxies.

Guilaine Lagache; Jean-Loup Puget; Herve Dole

2005-07-12T23:59:59.000Z

462

RPV stops bump off the background  

E-Print Network [OSTI]

We study the 8 TeV LHC reach on pair produced heavy flavored di-jet resonances. Motivated by theories of R-parity violation in supersymmetry we concentrate on a final state with two b-jets and two light jets. We exploit b-tagging to reject the background and discuss its importance at the trigger level to probe light stops. We present kinematical selections that can be used to isolate the signal as a bump in the mass distribution of the candidate resonances. We find that stops with R-parity violating couplings giving rise to fully hadronic final states can be observed in the current run of the LHC. Remarkably, the LHC can probe stop masses well within the range predicted by naturalness.

Roberto Franceschini; Riccardo Torre

2014-09-24T23:59:59.000Z

463

Invited Article: Characterization of background sources in space-based time-of-flight mass spectrometers  

SciTech Connect (OSTI)

For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward St, Ann Arbor, Michigan 48109 (United States); Orlando, T. M.; McLain, J. [Georgia Institute of Technology, 225 North Ave NW, Atlanta, Georgia 30332 (United States); Steiger, R. von [International Space Science Institute, Hallerstrasse 6, CH-3012 Bern, Switzerland and Physikalisches Institut, Universität Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

2014-09-15T23:59:59.000Z

464

High redshift AGNs and HI reionisation: limits from the unresolved X-ray background  

E-Print Network [OSTI]

The rapidly declining population of bright quasars at z~3 appears to make an increasingly small contribution to the ionising background at the HI Lyman limit. It is then generally though that massive stars in (pre-)galactic systems may provide the additional ionising flux needed to complete HI reionisation by z>6. A galaxy dominated background, however, may require that the escape fraction of Lyman continuum radiation from high redshift galaxies is as high as 10%, a value somewhat at odds with (admittedly scarce) observational constraints. High escape fractions from dwarf galaxies have been advocated, or, alternatively, a so-far undetected (or barely detected) population of unobscured, high-redshift faint AGNs. Here we question the latter hypothesis, and show that such sources, to be consistent with the measured level of the unresolved X-ray background at z=0, can provide a fraction of the HII filling factor not larger than 13% by z=6. The fraction rises to 10%.

Haardt, Francesco

2015-01-01T23:59:59.000Z

465

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

466

Microwaves and Chemistry: The Catalysis of an Exciting Marriage  

E-Print Network [OSTI]

. Product distrihution of microwave catalysis of carbon dioxide and water. Product Relative % yield Methane 55.1 Methanol 5.5 Acetone 4.7 C J alcohols 5.8 C 4 alcohols 28.4 o.5,------------------ 0.4 'C v >= 0.3 !i ;:I '" 0.2 &1... our first major success in cracking methane to ethylene and hydrogen [1,2], lhe destruction of chlorinated hydrocarbons [3,4], the hydrodesulfurization of hydrocracked pitch [5], and the microwave treatment of some Alberta oil sands and bitumens...

Wan, J.

467

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

468

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

469

Ceramic-glass-metal seal by microwave heating  

DOE Patents [OSTI]

A method for producing a ceramic-glass-metal seal by microwaving, mixes a slurry of glass sealing material and coupling agent and applies same to ceramic and metal workpieces. The slurry and workpieces are then insulated and microwaved at a power, time and frequency sufficient to cause a liquid-phase reaction in the slurry. The reaction of the glass sealing material forms a chemically different seal than that which would be formed by conventional heating because it is formed by diffusion rather than by wetting of the reactants.

Meek, T.T.; Blake, R.D.

1983-10-04T23:59:59.000Z

470

Applications for Microwave Generators in the Process Industries  

E-Print Network [OSTI]

. 14. Fix, S. R. "Microwave Devulcanization of Rub ber." (Goodyear Tire and Rubber Co., lincoln, NE, USA). US 4,104,205, Elastomerics, Vol. 112, No.6, pp. 1980, 38-40 (Eng). 15. Yamashita, I., Yamamoto, N., and Mima, S., "Decomposition of Waste... August 1978. 18. Novotny, D. S., et al. "Devulcanization of Sulfer-Vulcanized Elastomers." (Goodyear Tire and Rubber Co.) Ger. Offen. 2,700,306, 18 August 1977, US Appl. 646,821, 6 January 1976. 19. "Microwave Hardenable Molding Sand." (Ko matsu...

Humphrey, J. L.; Vasilakos, N. P.

1983-01-01T23:59:59.000Z

471

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 ResourceAwards SAGE Awards ,# , on behalf ofSCPDHubs+

472

Echo of the Big Bang Anisotropies in the  

E-Print Network [OSTI]

: Some Facts 7) CMB highly (impressively) Isotropic: - in each direction on the sky the radiation has Microwave Radiometer Cosmic Microwave Background #12;7/1/2009 6 Spectrum Blackbody Radiation John Mather: - photon energy 4) Energy Density Radiation evolves: Cosmic Radiation 44 )1()( ztarad 3 )(tanrad 1 )(tarad

Weijgaert, Rien van de

473

Radiation Control (Virginia)  

Broader source: Energy.gov [DOE]

The Department of Health is responsible for regulating radiation and radioactive materials in the Commonwealth of Virginia. Although the Department's Radiation Control Program primarily focuses on...

474

A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces  

SciTech Connect (OSTI)

A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 ?M of Mg{sup 2+} doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 ? coaxial input. Agreement between simulated and experimental results is shown.

Sidabras, Jason W.; Varanasi, Shiv K.; Hyde, James S. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Mett, Richard R. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin 53202 (United States); Swarts, Steven G. [Department of Radiation Oncology, University of Florida, Gainesville, Florida, 32610 (United States); Swartz, Harold M. [Department of Radiology, Geisel Medical School at Dartmouth, Hanover, New Hampshire 03755 (United States)

2014-10-15T23:59:59.000Z

475

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

476

ISO and the Cosmic Infrared Background  

E-Print Network [OSTI]

ISO observed, for the first time to such a high sensitivity level, the mid- and far-infrared universe. A Number of deep surveys were performed to probe the cosmological evolution of galaxies. In this review, I discuss and summarize results of mid-infrared ISOCAM and far-infrared ISOPHOT surveys, and show how our vision of the extragalactic infrared universe has become more accurate. In particular, ISO allowed us to resolve into sources a significant fraction of the Cosmic Infrared Background (CIB) in the mid-infrared, and to probe a fainter population in the far-infrared with the detection of the CIB fluctuations. Together with other wavelength data sets, the nature of ISO galaxies is now in the process of being understood. I also show that the high quality of the ISO data put strong constraints on the scenarios of galaxy evolution. This induced a burst in the development of models, yielding to a more coherent picture of galaxy evolution. I finally emphasize the potential of the ISO data archive in the field of observational cosmology, and describe the next steps, in particular the forthcoming cosmological surveys to be carried out by SIRTF.

Herve Dole

2002-12-12T23:59:59.000Z

477

K-mouflage Cosmology: the Background Evolution  

E-Print Network [OSTI]

We study the cosmology of K-mouflage theories at the background level. We show that the effects of the scalar field are suppressed at high matter density in the early Universe and only play a role in the late time Universe where the deviations of the Hubble rate from its $\\Lambda$-CDM counterpart can be of the order five percent for redshifts $1 \\lesssim z \\lesssim 5$. Similarly, we find that the equation of state can cross the phantom divide in the recent past and even diverge when the effective scalar energy density goes negative and subdominant compared to matter, preserving the positivity of the squared Hubble rate. These features are present in models for which Big Bang Nucleosynthesis is not affected. We analyze the fate of K-mouflage when the nonlinear kinetic terms give rise to ghosts, particle excitations with negative energy. In this case, we find that the K-mouflage theories can only be considered as an effective description of the Universe at low energy below $1$ keV. In the safe ghost-free models, we find that the equation of state always diverges in the past and changes significantly by a few percent since $z\\lesssim 1$.

Philippe Brax; Patrick Valageas

2014-11-30T23:59:59.000Z

478

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

SciTech Connect (OSTI)

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

479

ECRH microwave beam broadening in the edge turbulent plasma  

SciTech Connect (OSTI)

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

480

Use of passive microwave remote sensing to monitor soil moisture  

E-Print Network [OSTI]

January 1998) Abstract - Surface soil moisture is a key variable to describe the water and energy soil layer) is a key variable in the water and energy exchanges at the land surfaceReview Use of passive microwave remote sensing to monitor soil moisture Jean-Pierre Wignerona

Paris-Sud XI, Université de

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481

Engineering of Ferrite-Graphite Composite Media for Microwave Shields  

E-Print Network [OSTI]

Engineering of Ferrite-Graphite Composite Media for Microwave Shields Marina Koledintseva, PoornaAA@mpei.ru Abstract-- An electromagnetic shielding of objects using ferrite-graphite composites is considered- shielding; dielectric base material; ferrite- graphite composite, Maxwell Garnett formulation I

Koledintseva, Marina Y.