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Sample records for microwave background cmb

  1. Cosmic Microwave Background

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

    Cosmic Microwave Background Cosmic Microwave Background CMB.jpg The Cosmic Microwave Background (CMB) is relic radiation from a very early stage in the universe -- essentially a...

  2. Low-frequency measurements of the CMB (cosmic microwave background) spectrum

    SciTech Connect (OSTI)

    Kogut, A.; Bensadoun, M.; De Amici, G.; Levin, S.; Limon, M.; Smoot, G. ); Sironi, G. . Dipt. di Fisica); Bersanelli, M.; Bonelli, G. )

    1989-10-01

    As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in California. On average, these measurements suggest a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amnudsen-Scott Station at frequencies 0.82 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements from a polar observing site. 11 refs., 2 figs.

  3. Cosmic Microwave Background | Argonne National Laboratory

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

    Microwave Background Cosmic Microwave Background Remarkable progress has been made in the characterization of the cosmic microwave background radiation (CMB) over the last several years. It was nearly 30 years after the initial discovery of the CMB by Penzias and Wilson in 1965 before small differences in its intensity were measured by COBE and its spectrum was shown to be a blackbody to high precision. The finding helped motivate the inflation theory for the origin of the universe. In the past

  4. New measurements of the spectrum of the cosmic microwave background

    SciTech Connect (OSTI)

    Peterson, J.B.; Richards, P.L.; Bonomo, J.L.; Timusk, T.

    1984-06-01

    Accurate measurements of the spectrum of the cosmic microwave background (CMB) can provide useful tests of cosmological theories. The data set existing in 1982 has been summarized on a number of occasions and is shown. To first approximation the CMB is characterized by a single temperature and thus has a blackbody spectrum over the frequency range from 0.02 to 24 cm/sup -1/. The error limits given for these experiments are dominated by systematic errors and are often very subjective. Consequently, it is not clear how to analyze the data set in a valid way. The general impression, however, is of a scatter in the high frequency data that is somewhat larger than would be expected from the given error limits. We have designed a new apparatus to measure the spectrum of the CMB in the frequency range from 3 to 10 cm/sup -1/. 13 references, 5 figures.

  5. IS THE COSMIC MICROWAVE BACKGROUND ASYMMETRY DUE TO THE KINEMATIC DIPOLE?

    SciTech Connect (OSTI)

    Naselsky, P.; Zhao, W.; Kim, J.; Chen, S.

    2012-04-10

    Parity violation found in the cosmic microwave background (CMB) radiation is a crucial clue for the non-standard cosmological model or the possible contamination of various foreground residuals and/or calibration of the CMB data sets. In this paper, we study the directional properties of the CMB parity asymmetry by excluding the m = 0 modes in the definition of parity parameters. We find that the preferred directions of the parity parameters coincide with the CMB kinematic dipole, which implies that the CMB parity asymmetry may be connected with the possible contamination of the residual dipole component. We also find that such tendency is not only localized at l = 2, 3, but in the extended multipole ranges up to l {approx} 22.

  6. Cosmic microwave Background Map-making at the Petascale and Beyond |

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

    Argonne Leadership Computing Facility Cosmic microwave Background Map-making at the Petascale and Beyond Authors: Sudarsan, R., Borrill, J., Cantalupo, C., Kisner, T., Madduri, K., Oliker, L., Simon, H., Zheng, Y. The analysis of Cosmic Microwave Background (CMB) observations is a long-standing computational challenge, driven by the exponential growth in the size of the data sets being gathered. Since this growth is projected to continue for at least the next decade, it will be critical to

  7. MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10' to 5 degrees

    DOE R&D Accomplishments [OSTI]

    Ade, P.; Balbi, A.; Bock, J.; Borrill, J.; Boscaleri, A.; de Bernardis, P.; Ferreira, P. G.; Hanany, S.; Hristov, V. V.; Jaffe, A. H.; Lange, A. E.; Lee, A. T.; Mauskopf, P. D.; Netterfield, C. B.; Oh, S.; Pascale, E.; Rabii, B.; Richards, P. L.; Smoot, G. F.; Stompor, R.; Winant,C. D.; Wu, J. H. P.

    2005-06-04

    We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK. MAXIMA observed a 124 deg{sup 2} region of the sky with 10' resolution at frequencies of 150, 240 and 410 GHz. The data were calibrated using in-flight measurements of the CMB dipole anisotropy. A map of the CMB anisotropy was produced from three 150 and one 240 GHz photometer without need for foreground subtractions.

  8. MAXIMA-1: A Measurement of the Cosmic Microwave BackgroundAnisotropy on angular scales of 10' to 5 degrees

    SciTech Connect (OSTI)

    Ade, P.; Balbi, A.; Bock, J.; Borrill, J.; Boscaleri, A.; deBernardis, P.; Ferreira, P.G.; Hanany, S.; Hristov, V.V.; Jaffe, A.H.; Lange, A.E.; Lee, A.T.; Mauskopf, P.D.; Netterfield, C.B.; Oh, S.; Pascale, E.; Rabii, B.; Richards, P.L.; Smoot, G.F.; Stompor, R.; Winant,C.D.; Wu, J.H.P.

    2000-10-02

    We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK. MAXIMA observed a 124 deg region of the sky with 10' resolution at frequencies of 150, 240 and 410 GHz. The data were calibrated using in-flight measurements of the CMB dipole anisotropy. A map of the CMB anisotropy was produced from three 150 and one 240 GHz photometer without need for foreground subtractions. Analysis of this CMB map yields a power spectrum for the CMB anisotropy over the range 36 {le} {ell} {le} 785. The spectrum shows a peak with an amplitude of 78 {+-} 6 {mu}K at {ell} {approx_equal} 220 and an amplitude varying between {approx} 40 {mu}K and {approx} 50 {mu}K for 400 {approx}< {ell} {approx}< 785.

  9. BAYESIAN COMPONENT SEPARATION AND COSMIC MICROWAVE BACKGROUND ESTIMATION FOR THE FIVE-YEAR WMAP TEMPERATURE DATA

    SciTech Connect (OSTI)

    Dickinson, C.; Banday, A. J.; Jewell, J. B.; Gorski, K. M.; Huey, G.; Lawrence, C. R.; O'Dwyer, I. J.; Wandelt, B. D.

    2009-11-10

    A well-tested and validated Gibbs sampling code, that performs component separation and cosmic microwave background (CMB) power spectrum estimation, was applied to the WMAP five-year data. Using a simple model consisting of CMB, noise, monopoles, and dipoles, a 'per pixel' low-frequency power-law (fitting for both amplitude and spectral index), and a thermal dust template with a fixed spectral index, we found that the low-l (l < 50) CMB power spectrum is in good agreement with the published WMAP5 results. Residual monopoles and dipoles were found to be small (approx<3 muK) or negligible in the five-year data. We comprehensively tested the assumptions that were made about the foregrounds (e.g., dust spectral index, power-law spectral index prior, templates), and found that the CMB power spectrum was insensitive to these choices. We confirm the asymmetry of power between the north and south ecliptic hemispheres, which appears to be robust against foreground modeling. The map of low-frequency spectral indices indicates a steeper spectrum on average (beta = -2.97 +- 0.21) relative to those found at low (approxGHz) frequencies.

  10. Cosmic strings as the source of small-scale microwave background anisotropy

    SciTech Connect (OSTI)

    Pogosian, Levon; Tye, S.-H. Henry; Wasserman, Ira; Wyman, Mark E-mail: tye@lepp.cornell.edu E-mail: mwyman@perimeterinstitute.ca

    2009-02-15

    Cosmic string networks generate cosmological perturbations actively throughout the history of the universe. Thus, the string sourced anisotropy of the cosmic microwave background is not affected by Silk damping as much as the anisotropy seeded by inflation. The spectrum of perturbations generated by strings does not match the observed CMB spectrum on large angular scales (l < 1000) and is bounded to contribute no more than 10% of the total power on those scales. However, when this bound is marginally saturated, the anisotropy created by cosmic strings on small angular scales l {approx}> 2000 will dominate over that created by the primary inflationary perturbations. This range of angular scales in the CMB is presently being measured by a number of experiments; their results will test this prediction of cosmic string networks soon.

  11. Measurements of the cosmic microwave background temperature at 1.47 GHz

    SciTech Connect (OSTI)

    Bensadoun, M.J.

    1991-11-01

    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.

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

    SciTech Connect (OSTI)

    Bensadoun, M.J.

    1991-11-01

    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.

  13. A Measurement of Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters Using Data from the South Pole Telescope

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

    Baxter, E. J.; Keisler, R.; Dodelson, S.; Aird, K. A.; Allen, S. W.; Ashby, M. L.N.; Bautz, M.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; et al

    2015-06-22

    Clusters of galaxies are expected to gravitationally lens the cosmic microwave background (CMB) and thereby generate a distinct signal in the CMB on arcminute scales. Measurements of this effect can be used to constrain the masses of galaxy clusters with CMB data alone. Here we present a measurement of lensing of the CMB by galaxy clusters using data from the South Pole Telescope (SPT). We also develop a maximum likelihood approach to extract the CMB cluster lensing signal and validate the method on mock data. We quantify the effects on our analysis of several potential sources of systematic error andmore » find that they generally act to reduce the best-fit cluster mass. It is estimated that this bias to lower cluster mass is roughly 0.85σ in units of the statistical error bar, although this estimate should be viewed as an upper limit. Furthermore, we apply our maximum likelihood technique to 513 clusters selected via their Sunyaev–Zeldovich (SZ) signatures in SPT data, and rule out the null hypothesis of no lensing at 3.1σ. The lensing-derived mass estimate for the full cluster sample is consistent with that inferred from the SZ flux: M200,lens = 0.83+0.38-0.37 M200,SZ (68% C.L., statistical error only).« less

  14. Constraints on Cosmology from the Cosmic Microwave Background...

    Office of Scientific and Technical Information (OSTI)

    from the Cosmic Microwave Background Power Spectrum of the 2500-square degree SPT-SZ Survey Citation Details In-Document Search Title: Constraints on Cosmology from the Cosmic...

  15. Constraints on Cosmology from the Cosmic Microwave Background...

    Office of Scientific and Technical Information (OSTI)

    Power Spectrum of the 2500-square degree SPT-SZ Survey Citation Details In-Document Search Title: Constraints on Cosmology from the Cosmic Microwave Background Power Spectrum of ...

  16. FAST PIXEL SPACE CONVOLUTION FOR COSMIC MICROWAVE BACKGROUND SURVEYS WITH ASYMMETRIC BEAMS AND COMPLEX SCAN STRATEGIES: FEBeCoP

    SciTech Connect (OSTI)

    Mitra, S.; Rocha, G.; Gorski, K. M.; Lawrence, C. R.; Huffenberger, K. M.; Eriksen, H. K.; Ashdown, M. A. J. E-mail: graca@caltech.edu E-mail: Charles.R.Lawrence@jpl.nasa.gov E-mail: h.k.k.eriksen@astro.uio.no

    2011-03-15

    Precise measurement of the angular power spectrum of the cosmic microwave background (CMB) temperature and polarization anisotropy can tightly constrain many cosmological models and parameters. However, accurate measurements can only be realized in practice provided all major systematic effects have been taken into account. Beam asymmetry, coupled with the scan strategy, is a major source of systematic error in scanning CMB experiments such as Planck, the focus of our current interest. We envision Monte Carlo methods to rigorously study and account for the systematic effect of beams in CMB analysis. Toward that goal, we have developed a fast pixel space convolution method that can simulate sky maps observed by a scanning instrument, taking into account real beam shapes and scan strategy. The essence is to pre-compute the 'effective beams' using a computer code, 'Fast Effective Beam Convolution in Pixel space' (FEBeCoP), that we have developed for the Planck mission. The code computes effective beams given the focal plane beam characteristics of the Planck instrument and the full history of actual satellite pointing, and performs very fast convolution of sky signals using the effective beams. In this paper, we describe the algorithm and the computational scheme that has been implemented. We also outline a few applications of the effective beams in the precision analysis of Planck data, for characterizing the CMB anisotropy and for detecting and measuring properties of point sources.

  17. New constraints on cosmic polarization rotation from B-mode polarization in the cosmic microwave background

    SciTech Connect (OSTI)

    Alighieri, Sperello di Serego; Ni, Wei-Tou; Pan, Wei-Ping E-mail: weitou@gmail.com

    2014-09-01

    SPTpol, 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 to their analyses of the spectra to include in the model, in addition to the gravitational lensing and the inflationary gravitational wave components, and also the effects induced by the cosmic polarization rotation (CPR), if it exists within current upper limits. Although in principle our analysis would also lead to new constraints on CPR, in practice these can only be given on its fluctuations (??{sup 2}), since constraints on its mean angle are inhibited by the derotation 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 the theoretical model) gives the constraint (??{sup 2}){sup 1/2} < 27.3 mrad (1.56), with r = 0.194 0.033. These results show that the present data are consistent with no CPR detection and the constraint on CPR fluctuation is about 1.5. This method of constraining the CPR is new, is complementary to previous tests, which use the radio and optical/UV polarization of radio galaxies and the CMB E-mode polarization, and adds a new constraint for the sky areas observed by SPTpol, POLARBEAR, and BICEP2.

  18. PROBING THE EPOCH OF PRE-REIONIZATION BY CROSS-CORRELATING COSMIC MICROWAVE AND INFRARED BACKGROUND ANISOTROPIES

    SciTech Connect (OSTI)

    Atrio-Barandela, F.; Kashlinsky, A. E-mail: Alexander.Kashlinsky@nasa.gov

    2014-12-20

    The epoch of first star formation and the state of the intergalactic medium (IGM) at that time are not directly observable with current telescopes. The radiation from those early sources is now part of the cosmic infrared background (CIB) and, as these sources ionize the gas around them, the IGM plasma would produce faint temperature anisotropies in the cosmic microwave background (CMB) via the thermal Sunyaev-Zeldovich (TSZ) effect. While these TSZ anisotropies are too faint to be detected, we show that the cross-correlation of maps of source-subtracted CIB fluctuations from Euclid, with suitably constructed microwave maps at different frequencies, can probe the physical state of the gas during reionization and test/constrain models of the early CIB sources. We identify the frequency-combined, CMB-subtracted microwave maps from space- and ground-based instruments to show that they can be cross-correlated with the forthcoming all-sky Euclid CIB maps to detect the cross-power at scales ?5'-60' with signal-to-noise ratios (S/Ns) of up to S/N ? 4-8 depending on the contribution to the Thomson optical depth during those pre-reionization epochs (?? ? 0.05) and the temperature of the IGM (up to ?10{sup 4} K). Such a measurement would offer a new window to explore the emergence and physical properties of these first light sources.

  19. ON MEASURING THE COSMIC MICROWAVE BACKGROUND TEMPERATURE AT REDSHIFT 0.89

    SciTech Connect (OSTI)

    Sato, M.; Menten, K. M.; Reid, M. J.; Carilli, C. L.

    2013-02-20

    We report on a measurement of the temperature of the cosmic microwave background radiation field, T {sub CMB}, at z = 0.88582 by imaging HC{sub 3}N(3 <- 2) and (5 <- 4) absorption in the foreground galaxy of the gravitationally lens magnified radio source PKS 1830-211 using the Very Long Baseline Array and the phased Very Large Array. Low-resolution imaging of the data yields a value of T {sub rot} = 5.6{sup +2.5} {sub -0.9} K for the rotational temperature, T {sub rot}, which is consistent with the temperature of the cosmic microwave background at the absorber's redshift of 2.73(1 + z) K. However, our high-resolution imaging reveals that the absorption peak position of the foreground gas is offset from the continuum peak position of the synchrotron radiation from PKS 1830-211SW, which indicates that the absorbing cloud is covering only part of the emission from PKS 1830-211, rather than the entire core-jet region. This changes the line-to-continuum ratios, and we find T {sub rot} between 1.1 and 2.5 K, which is lower than the expected value. This shows that previous T {sub rot} measurements could be biased due to unresolved structure.

  20. FINGERPRINTS OF GALACTIC LOOP I ON THE COSMIC MICROWAVE BACKGROUND

    SciTech Connect (OSTI)

    Liu, Hao; Mertsch, Philipp

    2014-07-10

    We investigate possible imprints of galactic foreground structures such as the ''radio loops'' in the derived maps of the cosmic microwave background. Surprisingly, there is evidence for these not only at radio frequencies through their synchrotron radiation, but also at microwave frequencies where emission by dust dominates. This suggests the mechanism is magnetic dipole radiation from dust grains enriched by metallic iron or ferrimagnetic molecules. This new foreground we have identified is present at high galactic latitudes, and potentially dominates over the expected B-mode polarization signal due to primordial gravitational waves from inflation.

  1. Cosmic microwave background observables of small field models of inflation

    SciTech Connect (OSTI)

    Ben-Dayan, Ido; Brustein, Ram E-mail: ramyb@bgu.ac.il

    2010-09-01

    We construct a class of single small field models of inflation that can predict, contrary to popular wisdom, an observable gravitational wave signal in the cosmic microwave background anisotropies. The spectral index, its running, the tensor to scalar ratio and the number of e-folds can cover all the parameter space currently allowed by cosmological observations. A unique feature of models in this class is their ability to predict a negative spectral index running in accordance with recent cosmic microwave background observations. We discuss the new class of models from an effective field theory perspective and show that if the dimensionless trilinear coupling is small, as required for consistency, then the observed spectral index running implies a high scale of inflation and hence an observable gravitational wave signal. All the models share a distinct prediction of higher power at smaller scales, making them easy targets for detection.

  2. Large-Angle Anomalies in the CMB

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

    Copi, Craig J.; Huterer, Dragan; Schwarz, Dominik J.; Starkman, Glenn D.

    2010-01-01

    We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction of motion of the solar ssystem, and the unusually low power at these largest scales. We discuss these findings in relation to expectation from standard inflationary cosmology, their statistical significance, the tools to study them, and the various attempts to explain them.

  3. A measurement of the cosmic microwave background B-mode polarization power spectrum at sub-degree scales with POLARBEAR

    SciTech Connect (OSTI)

    Ade, P. A. R.; Akiba, Y.; Hasegawa, M.; Anthony, A. E.; Halverson, N. W.; Arnold, K.; Atlas, M.; Barron, D.; Boettger, D.; Elleflot, T.; Feng, C.; Borrill, J.; Errard, J.; Chapman, S.; Chinone, Y.; Flanigan, D.; Dobbs, M.; Gilbert, A.; Fabbian, G.; Collaboration: Polarbear Collaboration; and others

    2014-10-20

    We report a measurement of the B-mode polarization power spectrum in the cosmic microwave background (CMB) using the POLARBEAR experiment in Chile. The faint B-mode polarization signature carries information about the universe's entire history of gravitational structure formation, and the cosmic inflation that may have occurred in the very early universe. Our measurement covers the angular multipole range 500 < ? < 2100 and is based on observations of an effective sky area of 25 deg{sup 2} with 3.'5 resolution at 150 GHz. On these angular scales, gravitational lensing of the CMB by intervening structure in the universe is expected to be the dominant source of B-mode polarization. Including both systematic and statistical uncertainties, the hypothesis of no B-mode polarization power from gravitational lensing is rejected at 97.2% confidence. The band powers are consistent with the standard cosmological model. Fitting a single lensing amplitude parameter A{sub BB} to the measured band powers, A{sub BB}=1.120.61(stat){sub ?0.12}{sup +0.04}(sys)0.07(multi), where A{sub BB} = 1 is the fiducial WMAP-9 ?CDM value. In this expression, 'stat' refers to the statistical uncertainty, 'sys' to the systematic uncertainty associated with possible biases from the instrument and astrophysical foregrounds, and 'multi' to the calibration uncertainties that have a multiplicative effect on the measured amplitude A{sub BB}.

  4. A measurement of the cosmic microwave background damping tail...

    Office of Scientific and Technical Information (OSTI)

    the degeneracy that exists between the tensor-to-scalar ratio r and nsub s in large-scale CMB measurements, leading to an upper limit of r < 0.18 (95% C.L.) in the CDM+r model. ...

  5. Analysing the Effect on CMB in a Parity and Charge Parity Violating Varying

    Office of Scientific and Technical Information (OSTI)

    Alpha Theory (Journal Article) | SciTech Connect Analysing the Effect on CMB in a Parity and Charge Parity Violating Varying Alpha Theory Citation Details In-Document Search Title: Analysing the Effect on CMB in a Parity and Charge Parity Violating Varying Alpha Theory In this paper we study in detail the effect of our recently proposed model of parity and charge-parity (PCP) violating varying alpha on the Cosmic Microwave Background (CMB) photon passing through the intra galaxy-cluster

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

    SciTech Connect (OSTI)

    Samal, Pramoda Kumar; Jain, Pankaj; Saha, Rajib; Prunet, Simon; Souradeep, Tarun

    2010-05-01

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

  7. Low-Frequency Measurements of the CMB Spectrum

    SciTech Connect (OSTI)

    Kogut, A.; Bensadoun, M.; De Amici, Giovanni; Levin, S.; Limon,M.; Smoot, George F.; Sironi, G.; Bersanelli, M.; Bonelli, G.

    1989-10-01

    As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in California. On average, these measurements suggest a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amundsen-Scott Station at frequencies 0.82, 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements possible from a polar observing site.

  8. Low-frequency measurements of the CMB spectrum

    SciTech Connect (OSTI)

    Kogut, A.; Bensadoun, M.; Amici, G.D.; Levin, S.; Limon, M.; Smoot, G. Lawrence Berkeley Laboratory, Berkeley, CA Space Sciences Laboratory, Berkeley, CA ); Sironi, G. ); Bersanelli, M.; Bonelli, G. )

    1990-01-15

    As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in Calfornia. On average, these measurements suggests a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amundsen-Scott Station at frequencies 0.82, 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements possible from a polar observing site.

  9. A Flat Universe from High-Resolution Maps of the Cosmic MicrowaveBackground Radiation

    SciTech Connect (OSTI)

    de Bernardis, P.; Ade, P.A.R.; Bock, J.J.; Bond, J.R.; Borrill,J.; Boscaleri, A.; Coble, K.; Crill, B.P.; De Gasperis, G.; Farese, P.C.; Ferreira, P.G.; Ganga, K.; Giacometti, M.; Hivon, E.; Hristov, V.V.; Iacoangeli, A.; Jaffe, A.H.; Lange, A.E.; Martinis, L.; Masi, S.; Mason,P.; Mauskopf, P.D.; Melchiorri, A.; Miglio, L.; Montroy, T.; Netterfield,C.B.; Pascale, E.; Piacentini, F.; Pogosyan, D.; Prunet, S.; Rao, S.; Romeo, G.; Ruhl, J.E.; Scaramuzzi, F.; Sforna, D.; Vittorio, N.

    2000-04-28

    The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K Cosmic Microwave Background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole {ell}{sub peak} = (197 {+-} 6), with an amplitude DT{sub 200} = (69 {+-} 8){mu}K. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favored by standard inflationary scenarios.

  10. External priors for the next generation of CMB experiments

    SciTech Connect (OSTI)

    Manzotti, Alessandro; Dodelson, Scott; Park, Youngsoo

    2015-12-08

    Planned cosmic microwave background (CMB) experiments can dramatically improve what we know about neutrino physics, inflation, and dark energy. The low level of noise, together with improved angular resolution, will increase the signal to noise of the CMB polarized signal as well as the reconstructed lensing potential of high redshift large scale structure. Projected constraints on cosmological parameters are extremely tight, but these can be improved even further with information from external experiments. Here, we examine quantitatively the extent to which external priors can lead to improvement in projected constraints from a CMB-Stage IV (S4) experiment on neutrino and dark energy properties. We find that CMB S4 constraints on neutrino mass could be strongly enhanced by external constraints on the cold dark matter density $\\Omega_{c}h^{2}$ and the Hubble constant $H_{0}$. If polarization on the largest scales ($\\ell<50$) will not be measured, an external prior on the primordial amplitude $A_{s}$ or the optical depth $\\tau$ will also be important. A CMB constraint on the number of relativistic degrees of freedom, $N_{\\rm eff}$, will benefit from an external prior on the spectral index $n_{s}$ and the baryon energy density $\\Omega_{b}h^{2}$. Finally, an external prior on $H_{0}$ will help constrain the dark energy equation of state ($w$).

  11. Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure

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

    Abazajian, K. N.; Arnold, K.; Austermann, J.; Benson, B. A.; Bischoff, C.; Bock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; et al

    2014-03-15

    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 σ (σmv) = 16 meV and σ (Neff)(Neff) = 0.020.more » Such a mass measurement will produce a high significance detection of non-zero σmνσmν, 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.« less

  12. Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure

    SciTech Connect (OSTI)

    Abazajian, K. N.; 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.; Kuo, C. -L.; 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.; Slosar, A.; Smith, K. M.; Spergel, D.; Staggs, S. T.; Stark, A.; Stompor, R.; Wang, G.; Watson, S.; Wollack, E. J.; Wu, W. L.K.; Yoon, K. W.; Zahn, O.

    2014-03-15

    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.

  13. Neutrino physics from the cosmic microwave background and large scale structure

    SciTech Connect (OSTI)

    Abazajian, K. N.; Arnold, K.; Austermann, J. E.; Benson, B. A.; Bischoff, C.; Brock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; Chang, C. L.

    2015-03-15

    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 σ (σmν)(σmν) = 16 meV and σ (Neff)(Neff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero σmνσmν, 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 NeffNeff 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 View the MathML sourceNeff=3.046.

  14. COSMIC FLOW FROM TWO MICRON ALL-SKY REDSHIFT SURVEY: THE ORIGIN OF COSMIC MICROWAVE BACKGROUND DIPOLE AND IMPLICATIONS FOR LAMBDACDM COSMOLOGY

    SciTech Connect (OSTI)

    Lavaux, Guilhem; Mohayaee, Roya; Colombi, Stephane

    2010-01-20

    We generate the peculiar velocity field for the Two Micron All-Sky Redshift Survey (2MRS) catalog using an orbit-reconstruction algorithm. The reconstructed velocities of individual objects in 2MRS are well correlated with the peculiar velocities obtained from high-precision observed distances within 3000 km s{sup -1}. We estimate the mean matter density to be OMEGA{sub m} = 0.31 +- 0.05 by comparing observed to reconstructed velocities in this volume. The reconstructed motion of the Local Group in the rest frame established by distances within 3000 km s{sup -1} agrees with the observed motion and is generated by fluctuations within this volume, in agreement with observations. Having tested our method against observed distances, we reconstruct the velocity field of 2MRS in successively larger radii, to study the problem of convergence toward the cosmic microwave background (CMB) dipole. We find that less than half of the amplitude of the CMB dipole is generated within a volume enclosing the Hydra-Centaurus-Norma supercluster at around 40 h {sup -1} Mpc. Although most of the amplitude of the CMB dipole seems to be recovered by 120 h {sup -1} Mpc, the direction does not agree and hence we observe no convergence up to this scale. Due to dominant superclusters such as Shapley or Horologium-Reticulum in the southern hemisphere at scales above 120 h {sup -1} Mpc, one might need to go well beyond 200 h {sup -1} Mpc to fully recover the dipole vector. We develop a statistical model which allows us to estimate cosmological parameters from the reconstructed growth of convergence of the velocity of the Local Group toward the CMB dipole motion. For scales up to 60 h {sup -1} Mpc, assuming a Local Group velocity of 627 km s{sup -1}, we estimate OMEGA{sub m} h {sup 2} = 0.11 +- 0.06 and sigma{sub 8} = 0.9 +- 0.4, in agreement with WMAP5 measurements at the 1sigma level. However, for scales up to 100 h {sup -1} Mpc, we obtain OMEGA{sub m} h {sup 2} = 0.08 +- 0.03 and sigma{sub 8

  15. CMB dipole asymmetry from a fast roll phase

    SciTech Connect (OSTI)

    Mazumdar, Anupam; Wang, Lingfei

    2013-10-01

    The observed CMB (cosmic microwave background) dipole asymmetry cannot be explained by a single field model of inflation - it inevitably requires more than one field where one of the fields is responsible for amplifying the super-Hubble fluctuations beyond the pivot scale. Furthermore the current constraints on f{sub NL} and ?{sub NL} require that such an amplification cannot produce large non-Gaussianity. In this paper we propose a model to explain this dipole asymmetry from a spectator field, which is responsible for generating all the curvature perturbations, but has a temporary fast roll phase before the Hubble exit of the pivot scale. The current data prefers spectator scenario because it leaves no isocurvature perturbations. The spectator model will also satisfy the well-known constraints arising from quasars, and the quadrupole and octupole of the CMB.

  16. Cross-correlation studies between CMB temperature anisotropies and 21 cm fluctuations

    SciTech Connect (OSTI)

    Cooray, Asantha

    2004-09-15

    During the transition from a neutral to a fully reionized universe, scattering of cosmic microwave background (CMB) photons via free electrons leads to a new anisotropy contribution to the temperature distribution. If the reionization process is inhomogeneous and patchy, the era of reionization is also visible via brightness temperature fluctuations in the redshifted 21 cm line emission from neutral hydrogen. Since regions containing electrons and neutral hydrogen are expected to trace the same underlying density field, the two are (anti)correlated and this is expected to be reflected in the anisotropy maps via a correlation between arcminute-scale CMB temperature and the 21 cm background. In terms of the angular cross-power spectrum, unfortunately, this correlation is insignificant due to a geometric cancellation associated with second-order CMB anisotropies. The same cross correlation between ionized and neutral regions, however, can be studied using a bispectrum involving large-scale velocity field of ionized regions from the Doppler effect, arcminute-scale CMB anisotropies during reionization, and the 21 cm background. While the geometric cancellation is partly avoided, the signal-to-noise ratio related to this bispectrum is reduced due to the large cosmic variance related to velocity fluctuations traced by the Doppler effect. Unless the velocity field during reionization can be independently established, it is unlikely that the correlation information related to the relative distribution of ionized electrons and regions containing neutral hydrogen can be obtained with a combined study involving CMB and 21 cm fluctuations.

  17. Non-Gaussianity in the cosmic microwave background anisotropies at recombination in the squeezed limit

    SciTech Connect (OSTI)

    Bartolo, N.; Matarrese, S.; Riotto, A. E-mail: sabino.matarrese@pd.infn.it

    2012-02-01

    We estimate analytically the second-order cosmic microwave background temperature anisotropies at the recombination epoch in the squeezed limit and we deduce the contamination of the primordial local non-Gaussianity. We find that the level of contamination corresponds to f{sub NL}{sup con} = O(1) which is below the sensitivity of present experiments and smaller than the value O(5) recently claimed in the literature.

  18. Reionization history and CMB parameter estimation

    SciTech Connect (OSTI)

    Dizgah, Azadeh Moradinezhad; Kinney, William H.; Gnedin, Nickolay Y. E-mail: gnedin@fnal.edu

    2013-05-01

    We study how uncertainty in the reionization history of the universe affects estimates of other cosmological parameters from the Cosmic Microwave Background. We analyze WMAP7 data and synthetic Planck-quality data generated using a realistic scenario for the reionization history of the universe obtained from high-resolution numerical simulation. We perform parameter estimation using a simple sudden reionization approximation, and using the Principal Component Analysis (PCA) technique proposed by Mortonson and Hu. We reach two main conclusions: (1) Adopting a simple sudden reionization model does not introduce measurable bias into values for other parameters, indicating that detailed modeling of reionization is not necessary for the purpose of parameter estimation from future CMB data sets such as Planck. (2) PCA analysis does not allow accurate reconstruction of the actual reionization history of the universe in a realistic case.

  19. Observed parity-odd CMB temperature bispectrum

    SciTech Connect (OSTI)

    Shiraishi, Maresuke; Liguori, Michele; Fergusson, James R. E-mail: michele.liguori@pd.infn.it

    2015-01-01

    Parity-odd non-Gaussianities create a variety of temperature bispectra in the cosmic microwave background (CMB), defined in the domain: ℓ{sub 1} + ℓ{sub 2} + ℓ{sub 3} = odd. These models are yet unconstrained in the literature, that so far focused exclusively on the more common parity-even scenarios. In this work, we provide the first experimental constraints on parity-odd bispectrum signals in WMAP 9-year temperature data, using a separable modal parity-odd estimator. Comparing theoretical bispectrum templates to the observed bispectrum, we place constraints on the so-called nonlineality parameters of parity-odd tensor non-Gaussianities predicted by several Early Universe models. Our technique also generates a model-independent, smoothed reconstruction of the bispectrum of the data for parity-odd configurations.

  20. CMB ISW-lensing bispectrum from cosmic strings

    SciTech Connect (OSTI)

    Yamauchi, Daisuke; Sendouda, Yuuiti; Takahashi, Keitaro E-mail: sendouda@cc.hirosaki-u.ac.jp

    2014-02-01

    We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW) effect, the so-called Gott-Kaiser-Stebbins (GKS) effect, to the CMB temperature fluctuation, which are thus naturally cross-correlated. We point out that, in the presence of such a correlation, yet another kind of the post-recombination CMB temperature bispectra, the ISW-lensing bispectra, will arise in the form of products of the auto- and cross-power spectra. We first present an analytic method to calculate the autocorrelation of the temperature fluctuations induced by the strings, and the cross-correlation between the temperature fluctuation and the lensing potential both due to the string network. In our formulation, the evolution of the string network is assumed to be characterized by the simple analytic model, the velocity-dependent one scale model, and the intercommutation probability is properly incorporated in order to characterize the possible superstringy nature. Furthermore, the obtained power spectra are dominated by the Poisson-distributed string segments, whose correlations are assumed to satisfy the simple relations. We then estimate the signal-to-noise ratios of the string-induced ISW-lensing bispectra and discuss the detectability of such CMB signals from the cosmic string network. It is found that in the case of the smaller string tension, Gμ << 10{sup -7}, the ISW-lensing bispectrum induced by a cosmic string network can constrain the string-model parameters even more tightly than the purely GKS-induced bispectrum in the ongoing and future CMB observations on small scales.

  1. CMB lensing reconstruction in the presence of diffuse polarized foregrounds

    SciTech Connect (OSTI)

    Fantaye, Y.; Baccigalupi, C.; Leach, S.M.; Yadav, A.P.S. E-mail: bacci@sissa.it E-mail: ayadav@physics.ucsd.edu

    2012-12-01

    The measurement and characterization of the lensing of the cosmic microwave background (CMB) is key goal of the current and next generation of CMB experiments. We perform a case study of a three-channel balloon-borne CMB experiment observing the sky at (l,b)=(250°,−38°) and attaining a sensitivity of 5.25 μK−arcmin with 8' angular resolution at 150 GHz, in order to assess whether the effect of polarized Galactic dust is expected to be a significant contaminant to the lensing signal reconstructed using the EB quadratic estimator. We find that for our assumed dust model, polarization fractions of about as low as a few percent may lead to a significant dust bias to the lensing convergence power spectrum. We investigated a parametric component separation method, proposed by Stompor et al. (2009), as well as a template cleaning method, for mitigating the effect of this dust bias. The template-based method recovers unbiased convergence power spectrum in all polarization fraction cases we considered, while for the component separation technique we find a dust contrast regime in which the accuracy of the profile likelihood spectral index estimate breaks down, and in which external information on the dust frequency scaling is needed. We propose a criterion for putting a requirement on the accuracy with which the dust spectral index must be estimated or constrained, and demonstrate that if this requirement is met, then the dust bias can be removed.

  2. An Analysis of Recent Measurements of the Temperature of the Cosmic Microwave Background Radiation

    DOE R&D Accomplishments [OSTI]

    Smoot, G.; Levin, S. M.; Witebsky, C.; De Amici, G.; Rephaeli, Y.

    1987-07-01

    This paper presents an analysis of the results of recent temperature measurements of the cosmic microwave background radiation (CMBR). The observations for wavelengths longer than 0.1 cum are well fit by a blackbody spectrum at 2.74{+ or -}0.0w K; however, including the new data of Matsumoto et al. (1987) the result is no longer consistent with a Planckian spectrum. The data are described by a Thomson-distortion parameter u=0.021{+ or -}0.002 and temperature 2.823{+ or -}0.010 K at the 68% confidence level. Fitting the low-frequency data to a Bose-Einstein spectral distortion yields a 95% confidence level upper limit of 1.4 x 10{sup -2} on the chemical potential mu{sub 0}. These limits on spectral distortions place restrictions on a number of potentially interesting sources of energy release to the CMBR, including the hot intergalactic medium proposed as the source of the X-ray background.

  3. A guide to designing future ground-based cosmic microwave background experiments

    SciTech Connect (OSTI)

    Wu, W. L. K.; Kuo, C. L.; Errard, J.; Dvorkin, C.; Lee, A. T.; McDonald, P.; Zahn, O.; Slosar, A.

    2014-06-20

    In this follow-up work to the high energy physics Community Summer Study 2013 (aka SNOWMASS), we explore the scientific capabilities of a future Stage IV cosmic microwave background polarization experiment under various assumptions on detector count, resolution, and sky coverage. We use the Fisher matrix technique to calculate the expected uncertainties of cosmological parameters in ??CDM that are especially relevant to the physics of fundamental interactions, including neutrino masses, effective number of relativistic species, dark energy equation of state, dark matter annihilation, and inflationary parameters. To further chart the landscape of future cosmology probes, we include forecasted results from the baryon acoustic oscillation signal as measured by Dark Energy Spectroscopic Instrument to constrain parameters that would benefit from low redshift information. We find the following best 1? constraints: ?(M {sub ?}) = 15 meV, ?(N {sub eff}) = 0.0156, dark energy figure of merit = 303, ?(p {sub ann}) = 0.00588 3 10{sup 26} cm{sup 3} s{sup 1} GeV{sup 1}, ?(? {sub K}) = 0.00074, ?(n{sub s} ) = 0.00110, ?(? {sub s}) = 0.00145, and ?(r) = 0.00009. We also detail the dependencies of the parameter constraints on detector count, resolution, and sky coverage.

  4. Photon-axion conversion as a mechanism for supernova dimming: Limits from CMB spectral distortion

    SciTech Connect (OSTI)

    Mirizzi, Alessandro; Raffelt, Georg G.; Serpico, Pasquale D.

    2005-07-15

    Axion-photon conversion induced by intergalactic magnetic fields has been proposed as an explanation for the dimming of distant supernovae of type Ia (SNe Ia) without cosmic acceleration. The effect depends on the intergalactic electron density n{sub e} as well as the B-field strength and domain size. We show that for n{sub e} < or approx. 10{sup -9} cm{sup -3} the same mechanism would cause excessive spectral distortion of the cosmic microwave background (CMB). This small-n{sub e} parameter region had been left open by the most restrictive previous constraints based on the dispersion of quasar (QSO) spectra. The combination of CMB and QSO limits suggests that the photon-axion conversion mechanism can only play a subleading role for SN Ia dimming. A combined analysis of all the observables affected by the photon-axion oscillations would be required to give a final verdict on the viability of this model.

  5. Degree-scale cosmic microwave background polarization measurements from three years of BICEP1 data

    SciTech Connect (OSTI)

    Barkats, D.; Aikin, R.; Bock, J. J.; Filippini, J.; Hristov, V. V.; Bischoff, C.; Buder, I.; Kovac, J. M.; Kaufman, J. P.; Keating, B. G.; Bierman, E. M.; Su, M.; Ade, P. A. R.; Battle, J. O.; Dowell, C. D.; Chiang, H. C.; Duband, L.; Hivon, E. F.; Holzapfel, W. L.; Jones, W. C.; and others

    2014-03-10

    BICEP1 is a millimeter-wavelength telescope designed specifically to measure the inflationary B-mode polarization of the cosmic microwave background at degree angular scales. We present results from an analysis of the data acquired during three seasons of observations at the South Pole (2006-2008). This work extends the two-year result published in Chiang et al., with additional data from the third season and relaxed detector-selection criteria. This analysis also introduces a more comprehensive estimation of band power window functions, improved likelihood estimation methods, and a new technique for deprojecting monopole temperature-to-polarization leakage that reduces this class of systematic uncertainty to a negligible level. We present maps of temperature, E- and B-mode polarization, and their associated angular power spectra. The improvement in the map noise level and polarization spectra error bars are consistent with the 52% increase in integration time relative to Chiang et al. We confirm both self-consistency of the polarization data and consistency with the two-year results. We measure the angular power spectra at 21 ≤ ℓ ≤ 335 and find that the EE spectrum is consistent with Lambda cold dark matter cosmology, with the first acoustic peak of the EE spectrum now detected at 15σ. The BB spectrum remains consistent with zero. From B-modes only, we constrain the tensor-to-scalar ratio to r=0.03{sub −0.23}{sup +0.27}, or r < 0.70 at 95% confidence level.

  6. Cosmological implications of the CMB large-scale structure

    SciTech Connect (OSTI)

    Melia, Fulvio

    2015-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) and Planck may have uncovered several anomalies in the full cosmic microwave background (CMB) sky that could indicate possible new physics driving the growth of density fluctuations in the early universe. These include an unusually low power at the largest scales and an apparent alignment of the quadrupole and octopole moments. In a ?CDM model where the CMB is described by a Gaussian Random Field, the quadrupole and octopole moments should be statistically independent. The emergence of these low probability features may simply be due to posterior selections from many such possible effects, whose occurrence would therefore not be as unlikely as one might naively infer. If this is not the case, however, and if these features are not due to effects such as foreground contamination, their combined statistical significance would be equal to the product of their individual significances. In the absence of such extraneous factors, and ignoring the biasing due to posterior selection, the missing large-angle correlations would have a probability as low as ?0.1% and the low-l multipole alignment would be unlikely at the ?4.9% level; under the least favorable conditions, their simultaneous observation in the context of the standard model could then be likely at only the ?0.005% level. In this paper, we explore the possibility that these features are indeed anomalous, and show that the corresponding probability of CMB multipole alignment in the R{sub h}=ct universe would then be ?710%, depending on the number of large-scale SachsWolfe induced fluctuations. Since the low power at the largest spatial scales is reproduced in this cosmology without the need to invoke cosmic variance, the overall likelihood of observing both of these features in the CMB is ?7%, much more likely than in ?CDM, if the anomalies are real. The key physical ingredient responsible for this difference is the existence in the former of a maximum fluctuation

  7. How well can future CMB missions constrain cosmic inflation?

    SciTech Connect (OSTI)

    Martin, Jérôme; Vennin, Vincent; Ringeval, Christophe E-mail: christophe.ringeval@uclouvain.be

    2014-10-01

    We study how the next generation of Cosmic Microwave Background (CMB) measurement missions (such as EPIC, LiteBIRD, PRISM and COrE) will be able to constrain the inflationary landscape in the hardest to disambiguate situation in which inflation is simply described by single-field slow-roll scenarios. Considering the proposed PRISM and LiteBIRD satellite designs, we simulate mock data corresponding to five different fiducial models having values of the tensor-to-scalar ratio ranging from 10{sup -1} down to 10{sup -7}. We then compute the Bayesian evidences and complexities of all Encyclopædia Inflationaris models in order to assess the constraining power of PRISM alone and LiteBIRD complemented with the Planck 2013 data. Within slow-roll inflation, both designs have comparable constraining power and can rule out about three quarters of the inflationary scenarios, compared to one third for Planck 2013 data alone. However, we also show that PRISM can constrain the scalar running and has the capability to detect a violation of slow roll at second order. Finally, our results suggest that describing an inflationary model by its potential shape only, without specifying a reheating temperature, will no longer be possible given the accuracy level reached by the future CMB missions.

  8. Signatures of anisotropic sources in the trispectrum of the cosmic microwave background

    SciTech Connect (OSTI)

    Shiraishi, Maresuke; Komatsu, Eiichiro; Peloso, Marco E-mail: komatsu@mpa-garching.mpg.de

    2014-04-01

    Soft limits of N-point correlation functions, in which one wavenumber is much smaller than the others, play a special role in constraining the physics of inflation. Anisotropic sources such as a vector field during inflation generate distinct angular dependence in all these correlators, and introduce a fix privileged direction in our sky. In this paper we focus on the four-point correlator (the trispectrum T). We adopt a parametrization motivated by models in which the inflaton ? is coupled to a vector field through a I{sup 2}(?)F{sup 2} interaction, namely T{sub ?}(k{sub 1},k{sub 2},k{sub 3},k{sub 4})??{sub n}d{sub n}[P{sub n}( k-circumflex {sub 1}? k-circumflex {sub 3})+P{sub n}( k-circumflex {sub 1}? k-circumflex {sub 12})+P{sub n}( k-circumflex {sub 3}? k-circumflex {sub 12})]P{sub ?}(k{sub 1})P{sub ?}(k{sub 3})P{sub ?}(k{sub 12})+(23perm), where P{sub n} denotes the Legendre polynomials. This shape is enhanced when the wavenumbers of the diagonals of the quadrilateral are much smaller than the sides, k{sub i}. The coefficient of the isotropic part, d{sub 0}, is equal to ?{sub NL}/6 discussed in the literature. A I{sup 2}(?)F{sup 2} interaction generates d{sub 2} = 2d{sub 0} which is, in turn, related to the quadrupole modulation parameter of the power spectrum, g{sub *}, as d{sub 2} ? 14|g{sub *}|N{sup 2} with N ? 60. We show that d{sub 0} and d{sub 2} can be equally well-constrained: the expected 68% CL error bars on these coefficients from a cosmic-variance-limited experiment measuring temperature anisotropy of the cosmic microwave background up to ?{sub max} = 2000 are ?d{sub 2} ? 4?d{sub 0} = 105. Therefore, we can reach |g{sub *}| = 10{sup ?3} by measuring the angle-dependent trispectrum. The current upper limit on ?{sub NL} from the Planck temperature maps yields |g{sub *}| < 0.02 (95% CL)

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

    Tech Transfer Success Stories * 2010 Background 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 catalysts must become more durable, effcient, and inexpensive before they are practical and cost-effective. Most fuel cells use platinum or platinum alloys as catalysts, but the limited supply of platinum is a potential barrier to widespread fuel cell use. Innovative Edge Sandia

  14. INTRODUCING MEXICAN NEEDLETS FOR CMB ANALYSIS: ISSUES FOR PRACTICAL APPLICATIONS AND COMPARISON WITH STANDARD NEEDLETS

    SciTech Connect (OSTI)

    Scodeller, S.; Rudjord, Oe.; Hansen, F. K. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Marinucci, D. [Dipartimento di Matematica, Universita di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, I-00133 Roma (Italy); Geller, D.; Mayeli, A., E-mail: sandro.scodeller@astro.uio.no [Department of Mathematics, Stony Brook University, Stony Brook, NY 11794-3651 (United States)

    2011-06-01

    Over the last few years, needlets have emerged as a useful tool for the analysis of cosmic microwave background (CMB) data. Our aim in this paper is first to introduce into the CMB literature a different form of needlets, known as Mexican needlets, first discussed in the mathematical literature by Geller and Mayeli. We then proceed with an extensive study of the properties of both standard and Mexican needlets; these properties depend on some parameters which can be tuned in order to optimize the performance for a given application. Our second aim in this paper is then to give practical advice on how to adjust these parameters for WMAP and Planck data in order to achieve the best properties for a given problem in CMB data analysis. In particular, we investigate localization properties in real and harmonic space and propose a recipe for quantifying the influence of galactic and point-source masks on the needlet coefficients. We also show that for certain parameter values, the Mexican needlets provide a close approximation to the Spherical Mexican Hat Wavelets (whence their name), with some advantages concerning their numerical implementation and derivation of their statistical properties.

  15. What is the distance to the CMB?

    SciTech Connect (OSTI)

    Clarkson, Chris; Umeh, Obinna; Maartens, Roy; Durrer, Ruth E-mail: umeobinna@gmail.com E-mail: Ruth.Durrer@unige.ch

    2014-11-01

    The success of precision cosmology depends not only on accurate observations, but also on the theoretical model --- which must be understood to at least the same level of precision. Subtle relativistic effects can lead to biased measurements if they are neglected. One such effect gives a systematic shift in the distance-redshift relation away from its background value, due to the non-linear relativistic conservation of total photon flux. We also show directly how this shift follows from a fully relativistic analysis of the geodesic deviation equation. We derive the expectation value of the shift using second-order perturbations about a concordance background, and show that the distance to last scattering is increased by 1%. We argue that neglecting this shift could lead to a significant bias in the background cosmological parameters, because it alters the meaning of the background model. A naive adjustment of CMB parameter estimation if this shift is really a correction to the background would raise the H{sub 0} value inferred from the CMB by 5%, potentially removing the tension with local measurements of H{sub 0}. Other CMB parameters which depend on the distance would also be shifted by ? 1? when combined with local H{sub 0} data. While our estimations rely on a simplistic analysis, they nevertheless illustrate that accurately defining the background model in terms of the expectation values of observables is critical when we aim to determine the model parameters at the sub-percent level.

  16. CMB @ 50 & NERSC

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

    CMB @ 50 & NERSC @ 40 Prof. George F. Smoot Paris Centre for Cosmological Physics ( PCCP) Université Sorbonne Paris Cité / Laboratoire APC Physics Department; Lawrence Berkeley NaOonal Lab BCCP University of California at Berkeley 6/4/14 G. F. Smoot NERSC@40 1 ENIAC E lectronic Numerical Integrator And Computer was the first electronic general---purpose computer. It was Turing---complete, digital, and capable of being reprogrammed to solve "a large class of numerical problems''. ENIAC

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

    SciTech Connect (OSTI)

    Sunyaev, Rashid A.; Khatri, Rishi E-mail: khatri@mpa-garching.mpg.de

    2013-03-01

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

  18. POWER ASYMMETRY IN COSMIC MICROWAVE BACKGROUND FLUCTUATIONS FROM FULL SKY TO SUB-DEGREE SCALES: IS THE UNIVERSE ISOTROPIC?

    SciTech Connect (OSTI)

    Hansen, F. K.; Eriksen, H. K.; Lilje, P. B.; Banday, A. J.; Gorski, K. M. E-mail: h.k.k.eriksen@astro.uio.n E-mail: banday@MPA-Garching.MPG.D

    2009-10-20

    We repeat and extend the analysis of Eriksen et al. and Hansen et al., testing the isotropy of the cosmic microwave background fluctuations. We find that the hemispherical power asymmetry previously reported for the largest scales l = 2-40 extends to much smaller scales. In fact, for the full multipole range l = 2-600, significantly more power is found in the hemisphere centered at (theta = 107{sup 0} +- 10{sup 0}, phi = 226{sup 0} +- 10{sup 0}) in galactic co-latitude and longitude than in the opposite hemisphere, consistent with the previously detected direction of asymmetry for l = 2-40. We adopt a model selection test where the direction and amplitude of asymmetry, as well as the multipole range, are free parameters. A model with an asymmetric distribution of power for l = 2-600 is found to be preferred over the isotropic model at the 0.4% significance level, taking into account the additional parameters required to describe it. A similar direction of asymmetry is found independently in all six subranges of 100 multipoles between l = 2-600. None of our 9800 isotropic simulated maps show a similarly consistent direction of asymmetry over such a large multipole range. No known systematic effects or foregrounds are found to be able to explain the asymmetry.

  19. CMB lensing tomography with the DES Science Verification galaxies

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

    Giannantonio, T.

    2016-01-07

    We measure the cross-correlation between the galaxy density in the Dark Energy Survey (DES) Science Verification data and the lensing of the cosmic microwave background (CMB) as reconstructed with the Planck satellite and the South Pole Telescope (SPT). When using the DES main galaxy sample over the full redshift range 0.2 < zphot < 1.2, a cross-correlation signal is detected at 6σ and 4σ with SPT and Planck respectively. We then divide the DES galaxies into five photometric redshift bins, finding significant (>2σ) detections in all bins. Comparing to the fiducial Planck cosmology, we find the redshift evolution of themore » signal matches expectations, although the amplitude is consistently lower than predicted across redshift bins. We test for possible systematics that could affect our result and find no evidence for significant contamination. Finally, we demonstrate how these measurements can be used to constrain the growth of structure across cosmic time. We find the data are fit by a model in which the amplitude of structure in the z < 1.2 universe is 0.73 ± 0.16 times as large as predicted in the LCDM Planck cosmology, a 1.7σ deviation.« less

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

    SciTech Connect (OSTI)

    Carbone, Carmelita; Baldi, Marco; Baccigalupi, Carlo E-mail: marco.baldi5@unibo.it E-mail: bacci@sissa.it

    2013-09-01

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

  1. Constraints on standard and non-standard early universe models from CMB B-mode polarization

    SciTech Connect (OSTI)

    Ma, Yin-Zhe; Brown, Michael L.; Zhao, Wen E-mail: Wen.Zhao@astro.cf.ac.uk

    2010-10-01

    We investigate the observational signatures of three models of the early Universe in the B-mode polarization of the Cosmic Microwave Background (CMB) radiation. In addition to the standard single field inflationary model, we also consider the constraints obtainable on the loop quantum cosmology model (from Loop Quantum Gravity) and on cosmic strings, expected to be copiously produced during the latter stages of Brane inflation. We first examine the observational features of the three models, and then use current B-mode polarization data from the BICEP and QUaD experiments to constrain their parameters. We also examine the detectability of the primordial B-mode signal predicted by these models and forecast the parameter constraints achievable with future CMB polarization experiments. We find that: (a) since B-mode polarization measurements are mostly unaffected by parameter degeneracies, they provide the cleanest probe of these early Universe models; (b) using the BICEP and QUaD data we obtain the following parameter constraints: r = 0.02{sup +0.31}{sub −0.26} (1σ for the tensor-to-scalar ratio in the single field inflationary model); m < 1.36 × 10{sup −8}M{sub pl} and k{sub *} < 2.43 × 10{sup −4} Mpc{sup −1} (1σ for the mass and scale parameters in the loop quantum cosmology model); and Gμ < 5.77 × 10{sup −7} (1σ for the cosmic string tension); (c) future CMB observations (both satellite missions and forthcoming sub-orbital experiments) will provide much more rigorous tests of these early Universe models.

  2. Analytical model for CMB temperature angular power spectrum from cosmic (super-)strings

    SciTech Connect (OSTI)

    Yamauchi, Daisuke; Yoo, Chul-Moon; Sasaki, Misao; Takahashi, Keitaro; Sendouda, Yuuiti

    2010-09-15

    We present a new analytical method to calculate the small angle cosmic microwave background (CMB) temperature angular power spectrum due to cosmic (super-)string segments. In particular, using our method, we clarify the dependence on the intercommuting probability P. We find that the power spectrum is dominated by Poisson-distributed string segments. The power spectrum for a general value of P has a plateau on large angular scales and shows a power-law decrease on small angular scales. The resulting spectrum in the case of conventional cosmic strings is in very good agreement with the numerical result obtained by Fraisse et al.. Then we estimate the upper bound on the dimensionless tension of the string for various values of P by assuming that the fraction of the CMB power spectrum due to cosmic (super-)strings is less than ten percent at various angular scales up to l=2000. We find that the amplitude of the spectrum increases as the intercommuting probability. As a consequence, strings with smaller intercommuting probabilities are found to be more tightly constrained.

  3. Primordial Magnetic Field Effects on the CMB and Large-Scale Structure

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

    Yamazaki, Dai G.; Ichiki, Kiyotomo; Kajino, Toshitaka; Mathews, Grant J.

    2010-01-01

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

  4. PROBING THE UNIVERSE'S TILT WITH THE COSMIC INFRARED BACKGROUND DIPOLE

    SciTech Connect (OSTI)

    Fixsen, D. J.; Kashlinsky, A. E-mail: alexander.kashlinsky@nasa.gov

    2011-06-10

    Conventional interpretation of the observed cosmic microwave background (CMB) dipole is that all of it is produced by local peculiar motions. Alternative explanations requiring part of the dipole to be primordial have received support from measurements of large-scale bulk flows. A test of the two hypotheses is whether other cosmic dipoles produced by collapsed structures later than the last scattering coincide with the CMB dipole. One background is the cosmic infrared background (CIB) whose absolute spectrum was measured to {approx}30% by the COBE satellite. Over the 100-500 {mu}m wavelength range its spectral energy distribution can provide a probe of its alignment with the CMB. This is tested with the COBE FIRAS data set which is available for such a measurement because of its low noise and frequency resolution which are important for Galaxy subtraction. Although the FIRAS instrument noise is in principle low enough to determine the CIB dipole, the Galactic foreground is sufficiently close spectrally to keep the CIB dipole hidden. A similar analysis is performed with DIRBE, which-because of the limited frequency coverage-provides a poorer data set. We discuss strategies for measuring the CIB dipole with future instruments to probe the tilt and apply it to the Planck, Herschel, and the proposed Pixie missions. We demonstrate that a future FIRAS-like instrument with instrument noise a factor of {approx}10 lower than FIRAS would make a statistically significant measurement of the CIB dipole. We find that the Planck and Herschel data sets will not allow a robust CIB dipole measurement. The Pixie instrument promises a determination of the CIB dipole and its alignment with either the CMB dipole or the dipole galaxy acceleration vector.

  5. Modifications to the cosmic 21-cm background frequency spectrum by scattering via electrons in galaxy clusters

    SciTech Connect (OSTI)

    Cooray, Asantha

    2006-05-15

    The cosmic 21-cm background frequency spectrum related to the spin-flip transition of neutral hydrogen present during and before the era of reionization is rich in features associated with physical processes that govern transitions between the two spin states. The intervening electrons in foreground galaxy clusters inversely Compton scatter the 21-cm background spectrum and modify it just as the cosmic microwave background (CMB) spectrum is modified by inverse-Compton scattering. Towards typical galaxy clusters at low redshifts, the resulting modification is a few tenths milli-Kelvin correction to the few tens milli-Kelvin temperature of 21-cm signal relative to that of the cosmic microwave background blackbody spectrum. The modifications are mostly associated with sharp changes in the cosmic 21-cm background spectrum such as due to the onset of a Lyman-{alpha} radiation field or heating of neutral gas. Though low-frequency radio interferometers that are now planned for 21-cm anisotropy measurements are insensitive to the mean 21-cm spectrum, differential observations of galaxy clusters with these interferometers can be utilized to indirectly establish global features in the 21-cm frequency spectrum. We discuss the feasibility to detect the spectrum modified by clusters and find that, for upcoming interferometers, while a detection towards an individual cluster is challenging, one can average signals over a number of clusters, selected based on the strength of the Sunyave-Zel'dovich effect at high radio frequencies involving CMB scattering alone, to establish the mean 21-cm spectrum.

  6. Dipole anisotropy of galaxy distribution: Does the CMB rest frame exist in the local universe?

    SciTech Connect (OSTI)

    Itoh, Yousuke; Yahata, Kazuhiro; Takada, Masahiro

    2010-08-15

    The peculiar motion of the Earth causes a dipole anisotropy modulation in the distant galaxy distribution due to the aberration effect. However, the amplitude and angular direction of the effect is not necessarily the same as those of the cosmic microwave background (CMB) dipole anisotropy due to the growth of cosmic structures. In other words exploring the aberration effect may give us a clue to the horizon-scale physics perhaps related to the cosmic acceleration. In this paper we develop a method to explore the dipole angular modulation from the pixelized galaxy data on the sky, properly taking into account the covariances due to the shot noise and the intrinsic galaxy clustering contamination as well as the partial sky coverage. We applied the method to the galaxy catalogs constructed from the Sloan Digital Sky Survey Data Release 6 data. After constructing the four galaxy catalogs that are different in the ranges of magnitudes and photometric redshifts to study possible systematics, we found that the most robust sample against systematics indicates no dipole anisotropy in the galaxy distribution. This finding is consistent with the expectation from the concordance {Lambda}-dominated cold dark matter model. Finally, we argue that an almost full-sky galaxy survey such as Large Synoptic Survey Telescope may allow for a significant detection of the aberration effect of the CMB dipole having the precision of constraining the angular direction to {approx}20 deg in radius. Assuming a hypothetical Large Synoptic Survey Telescope galaxy survey, we find that this method can confirm or reject the result implied from a stacked analysis of the kinetic Sunyaev-Zel'dovich effect of X-ray luminous clusters in Kashlinsky et al. (2008, 2009) if the implied cosmic bulk flow is not extended out to the horizon.

  7. Relic vector field and CMB large scale anomalies

    SciTech Connect (OSTI)

    Chen, Xingang; Wang, Yi E-mail: yw366@cam.ac.uk

    2014-10-01

    We study the most general effects of relic vector fields on the inflationary background and density perturbations. Such effects are observable if the number of inflationary e-folds is close to the minimum requirement to solve the horizon problem. We show that this can potentially explain two CMB large scale anomalies: the quadrupole-octopole alignment and the quadrupole power suppression. We discuss its effect on the parity anomaly. We also provide analytical template for more detailed data comparison.

  8. Lensed CMB simulation and parameter estimation

    SciTech Connect (OSTI)

    Lewis, Antony

    2005-04-15

    Modelling of the weak lensing of the CMB will be crucial to obtain correct cosmological parameter constraints from forthcoming precision CMB anisotropy observations. The lensing affects the power spectrum as well as inducing non-Gaussianities. We discuss the simulation of full-sky CMB maps in the weak lensing approximation and describe a fast numerical code. The series expansion in the deflection angle cannot be used to simulate accurate CMB maps, so a pixel remapping must be used. For parameter estimation accounting for the change in the power spectrum but assuming Gaussianity is sufficient to obtain accurate results up to Planck sensitivity using current tools. A fuller analysis may be required to obtain accurate error estimates and for more sensitive observations. We demonstrate a simple full-sky simulation and subsequent parameter estimation at Planck-like sensitivity. The lensed CMB simulation and parameter estimation codes are publicly available.

  9. FERMI RULES OUT THE INVERSE COMPTON/CMB MODEL FOR THE LARGE-SCALE JET X-RAY EMISSION OF 3C 273

    SciTech Connect (OSTI)

    Meyer, Eileen T.; Georganopoulos, Markos

    2014-01-10

    The X-ray emission mechanism in large-scale jets of powerful radio quasars has been a source of debate in recent years, with two competing interpretations: either the X-rays are of synchrotron origin, arising from a different electron energy distribution than that producing the radio to optical synchrotron component, or they are due to inverse Compton scattering of cosmic microwave background photons (IC/CMB) by relativistic electrons in a powerful relativistic jet with bulk Lorentz factor ? ? 10-20. These two models imply radically different conditions in the large-scale jet in terms of jet speed, kinetic power, and maximum energy of the particle acceleration mechanism, with important implications for the impact of the jet on the large-scale environment. A large part of the X-ray origin debate has centered on the well-studied source 3C 273. Here we present new observations from Fermi which put an upper limit on the gamma-ray flux from the large-scale jet of 3C 273 that violates at a confidence greater that 99.9% the flux expected from the IC/CMB X-ray model found by extrapolation of the UV to X-ray spectrum of knot A, thus ruling out the IC/CMB interpretation entirely for this source when combined with previous work. Further, this upper limit from Fermi puts a limit on the Doppler beaming factor of at least ? <9, assuming equipartition fields, and possibly as low as ? <5, assuming no major deceleration of the jet from knots A throughD1.

  10. Unveiling acoustic physics of the CMB using nonparametric estimation of the temperature angular power spectrum for Planck

    SciTech Connect (OSTI)

    Aghamousa, Amir; Shafieloo, Arman; Arjunwadkar, Mihir; Souradeep, Tarun E-mail: shafieloo@kasi.re.kr E-mail: tarun@iucaa.ernet.in

    2015-02-01

    Estimation of the angular power spectrum is one of the important steps in Cosmic Microwave Background (CMB) data analysis. Here, we present a nonparametric estimate of the temperature angular power spectrum for the Planck 2013 CMB data. The method implemented in this work is model-independent, and allows the data, rather than the model, to dictate the fit. Since one of the main targets of our analysis is to test the consistency of the ΛCDM model with Planck 2013 data, we use the nuisance parameters associated with the best-fit ΛCDM angular power spectrum to remove foreground contributions from the data at multipoles ℓ ≥50. We thus obtain a combined angular power spectrum data set together with the full covariance matrix, appropriately weighted over frequency channels. Our subsequent nonparametric analysis resolves six peaks (and five dips) up to ℓ ∼1850 in the temperature angular power spectrum. We present uncertainties in the peak/dip locations and heights at the 95% confidence level. We further show how these reflect the harmonicity of acoustic peaks, and can be used for acoustic scale estimation. Based on this nonparametric formalism, we found the best-fit ΛCDM model to be at 36% confidence distance from the center of the nonparametric confidence set—this is considerably larger than the confidence distance (9%) derived earlier from a similar analysis of the WMAP 7-year data. Another interesting result of our analysis is that at low multipoles, the Planck data do not suggest any upturn, contrary to the expectation based on the integrated Sachs-Wolfe contribution in the best-fit ΛCDM cosmology.

  11. George Smoot, Blackbody, and Anisotropy of the Cosmic Microwave...

    Office of Scientific and Technical Information (OSTI)

    George Smoot, Blackbody, and Anisotropy of the Cosmic Microwave Background Radiation ... of the cosmic microwave background radiation." '1 Smoot previously won the Ernest ...

  12. Second Season QUIET Observations: Measurements of the CMB Polarization Power Spectrum at 95 GHz

    SciTech Connect (OSTI)

    Araujo, D.; Bischoff, C.; Brizius, A.; Buder, I.; Chinone, Y.; Cleary, K.; Dumoulin, R.N.; Kusaka, A.; Monsalve, R.; ss, S.K.N\\ae; Newburgh, L.B.; /Columbia U., CBA /Princeton U. /Caltech

    2012-07-01

    The Q/U Imaging ExperimenT (QUIET) has observed the cosmic microwave background (CMB) at 43 and 95GHz. The 43-GHz results have been published in QUIET Collaboration et al. (2011), and here we report the measurement of CMB polarization power spectra using the 95-GHz data. This data set comprises 5337 hours 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 square degrees 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{ell} (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 {ell} = 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 = {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.

  13. COLLOQUIUM: Small-scale CMB Cosmology: ACT, Planck and Beyond | Princeton

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

    Plasma Physics Lab June 25, 2014, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Small-scale CMB Cosmology: ACT, Planck and Beyond Dr. Renee Hlozek Princeton University Abstract: PDF icon COLL.06.25.14.pdf The Atacama Cosmology Telescope (ACT) has mapped the microwave sky to arcminute scales. We present constraints on parameters from the observations at 148 and 217 GHz respectively by ACT from three years of observations. We fit a model of primary cosmological and secondary foreground

  14. Suppressing CMB low multipoles with ISW effect

    SciTech Connect (OSTI)

    Das, Santanu; Souradeep, Tarun E-mail: tarun@iucaa.ernet.in

    2014-02-01

    Recent results of Planck data reveal that the power [1,2] in the low multipoles of the CMB angular power spectrum, approximately up to l = 30, is significantly lower than the theoretically predicted in the best fit ?CDM model. There are different known physical effects that can affect the power at low multipoles, such as features in the primordial power spectrum (PPS) in some models of inflation and ISW effect. In this paper we investigate the possibility of invoking the Integrated Sachs-Wolfe (ISW) effect to explain the power deficit at low multipoles. The ISW effect that originates from the late time expansion history of the universe is rich in possibilities given the limited understanding of the origin of dark energy (DE). It is a common understanding that the ISW effect adds to the power at the low multipoles of the CMB angular power spectrum. In this paper we carry out an analytic study to show that there are some expansion histories in which the ISW effect, instead of adding power, provides negative contribution to the power at low multipoles. Guided by the analytic study, we present examples of the features required in the late time expansion history of the universe that could explain the power deficiency through the ISW effect. We also show that an ISW origin of power deficiency is consistent, at present, with other cosmological observations that probe the expansion history such as distance modulus, matter power spectrum and the evolution of cluster number count. We also show that the ISW effect may be distinguished from power deficit originating from features in the PPS using the measurements of the CMB polarization spectrum at low multipoles expected from Planck. We conclude that the power at low multipoles of the CMB anisotropy could well be closely linked to Dark Energy puzzle in cosmology and this observation could be actually pointing to richer phenomenology of DE beyond the cosmological constant ?.

  15. Finite Cosmology and a CMB Cold Spot

    SciTech Connect (OSTI)

    Adler, R.J.; Bjorken, J.D.; Overduin, J.M.; /Stanford U., HEPL

    2006-03-20

    The standard cosmological model posits a spatially flat universe of infinite extent. However, no observation, even in principle, could verify that the matter extends to infinity. In this work we model the universe as a finite spherical ball of dust and dark energy, and obtain a lower limit estimate of its mass and present size: the mass is at least 5 x 10{sup 23}M{sub {circle_dot}} and the present radius is at least 50 Gly. If we are not too far from the dust-ball edge we might expect to see a cold spot in the cosmic microwave background, and there might be suppression of the low multipoles in the angular power spectrum. Thus the model may be testable, at least in principle. We also obtain and discuss the geometry exterior to the dust ball; it is Schwarzschild-de Sitter with a naked singularity, and provides an interesting picture of cosmogenesis. Finally we briefly sketch how radiation and inflation eras may be incorporated into the model.

  16. Extragalactic foreground contamination in temperature-based CMB lens reconstruction

    SciTech Connect (OSTI)

    Osborne, Stephen J.; Hanson, Duncan; Dor, Olivier E-mail: dhanson@physics.mcgill.ca

    2014-03-01

    We discuss the effect of unresolved point source contamination on estimates of the CMB lensing potential, from components such as the thermal Sunyaev-Zel'dovich effect, radio point sources, and the Cosmic Infrared Background. We classify the possible trispectra associated with such source populations, and construct estimators for the amplitude and scale-dependence of several of the major trispectra. We show how to propagate analytical models for these source trispectra to biases for lensing. We also construct a ''source-hardened'' lensing estimator which experiences significantly smaller biases when exposed to unresolved point sources than the standard quadratic lensing estimator. We demonstrate these ideas in practice using the sky simulations of Sehgal et al., for cosmic-variance limited experiments designed to mimic ACT, SPT, and Planck. We find that for radio sources and SZ the bias is significantly reduced, but for CIB it is essentially unchanged. However, by using the high-frequency, all-sky CIB measurements from Planck and Herschel it may be possible to suppress this contribution.

  17. Parity Violation Constraints Using Cosmic Microwave Background...

    Office of Scientific and Technical Information (OSTI)

    Menlo Park Harvard U. Stanford U., Phys. Dept. ; Ade, P. ; Cardiff U. ; Bock, J. ; Caltech Caltech, JPL ; Bowden, M. ; Cardiff U. KIPAC, Menlo Park Harvard U. Stanford ...

  18. Parity Violation Constraints Using Cosmic Microwave Background...

    Office of Scientific and Technical Information (OSTI)

    Dept. ; Ade, P. ; Cardiff U. ; Bock, J. ; Caltech Caltech, JPL ; Bowden, M. ; Cardiff U. KIPAC, Menlo Park Harvard U. Stanford U., Phys. Dept. ; Brown, M.L. ; Cambridge U. ...

  19. Rayleigh scattering: blue sky thinking for future CMB observations

    SciTech Connect (OSTI)

    Lewis, Antony

    2013-08-01

    Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal in any future space-based CMB missions. The later peak of the Rayleigh visibility compared to Thomson scattering gives an increased large-scale CMB polarization signal that is a greater than 4% effect for observed frequencies ν ∼> 500GHz. There is a similar magnitude suppression on small scales from additional damping. Due to strong correlation between the Rayleigh and primary signal, measurement of the Rayleigh component is limited by noise and foregrounds, not cosmic variance of the primary CMB, and should observable over a wide range of angular scales at frequencies 200GHz ∼< ν ∼< 800GHz. I give new numerical calculations of the temperature and polarization power spectra, and show that future CMB missions could measure the temperature Rayleigh cross-spectrum at high precision, detect the polarization from Rayleigh scattering, and also accurately determine the cross-spectra between the Rayleigh temperature signal and primary polarization. The Rayleigh scattering signal may provide a powerful consistency check on recombination physics. In principle it can be used to measure additional horizon-scale primordial perturbation modes at recombination, and distinguish a significant tensor mode B-polarization signal from gravitational lensing at the power spectrum level.

  20. Microwave detector

    DOE Patents [OSTI]

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

    1985-02-08

    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.

  1. Microwave detector

    DOE Patents [OSTI]

    Meldner, Heiner W.; Cusson, Ronald Y.; Johnson, Ray M.

    1986-01-01

    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.

  2. CMB hemispherical asymmetry: long mode modulation and non-Gaussianity

    SciTech Connect (OSTI)

    Namjoo, Mohammad Hossein; Baghram, Shant; Firouzjahi, Hassan; Abolhasani, Ali Akbar E-mail: abolhasani@ipm.ir E-mail: firouz@ipm.ir

    2014-08-01

    The observed hemispherical asymmetry in CMB map can be explained by modulation from a long wavelength super horizon mode which non-linearly couples to the CMB modes. We address the criticism in [1] about the role of non-Gaussianities in squeezed and equilateral configurations in generating hemispherical asymmetry from the long mode modulation. We stress that the modulation is sensitive to the non-Gaussianity in the squeezed limit. In addition, we demonstrate the validity of our approach in providing a consistency condition relating the amplitude of dipole asymmetry to f{sub NL} in the squeezed limit.

  3. A hydrodynamical approach to CMB ?-distortion from primordial perturbations

    SciTech Connect (OSTI)

    Pajer, Enrico; Zaldarriaga, Matias E-mail: matiasz@ias.edu

    2013-02-01

    Spectral distortion of the cosmic microwave background provides a unique opportunity to probe primordial perturbations on very small scales by performing large-scale measurements. We discuss in a systematic and pedagogic way all the relevant physical phenomena involved in the production and evolution of the ?-type spectral distortion. Our main results agree with previous estimates (in particular we show that a recently found factor of 3/4 arises from relativistic corrections to the wave energy). We also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon loading and photon heat conduction. Finally we provide formulae for the spatial dependence of ?-distortions and its transfer function between the end of the ?-era and now.

  4. Microwave generator

    DOE Patents [OSTI]

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

    1987-03-31

    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.

  5. Microwave furnace having microwave compatible dilatometer

    DOE Patents [OSTI]

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

    1992-03-24

    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.

  6. Microwave furnace having microwave compatible dilatometer

    DOE Patents [OSTI]

    Kimrey, Jr., Harold D.; Janney, Mark A.; Ferber, Mattison K.

    1992-01-01

    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.

  7. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for

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

    Advanced Manufacturing | Department of Energy Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing mw_rf_workshop_background_july2012.pdf (178.12 KB) More Documents & Publications Microwave and Radio Frequency Workshop

  8. Detecting dark matter annihilation with CMB polarization: Signatures and experimental prospects

    SciTech Connect (OSTI)

    Padmanabhan, Nikhil; Finkbeiner, Douglas P.

    2005-07-15

    Dark matter (DM) annihilation during hydrogen recombination (z{approx}1000) will alter the recombination history of the Universe, and affect the observed CMB temperature and polarization fluctuations. Unlike other astrophysical probes of DM, this is free of the significant uncertainties in modelling galactic physics, and provides a method to detect and constrain the cosmological abundances of these particles. We parametrize the effect of DM annihilation as an injection of ionizing energy at a rate {epsilon}{sub DM}, and argue that this simple 'on the spot' modification is a good approximation to the complicated interaction of the annihilation products with the photon-electron plasma. Generic models of DM do not change the redshift of recombination, but change the residual ionization after recombination. This broadens the surface of last scattering, suppressing the temperature fluctuations and enhancing the polarization fluctuations. We use the temperature and polarization angular power spectra to measure these deviations from the standard recombination history, and therefore, indirectly probe DM annihilation. The modifications to the temperature power spectrum are nearly degenerate with the primordial scalar spectral index and amplitude; current CMB data are therefore unable to put any constraints on the annihilation power. This degeneracy is broken by polarization; Planck will have the sensitivity to measure annihilation power {epsilon}{sub DM}(z=1000)>10{sup -15} eV/s/proton, while high sensitivity experiments (e.g. NASA's CMBpol) could improve that constraint to {epsilon}{sub DM}(z=1000)>4x10{sup -16} eV/s/proton, assuming a fractional detector sensitivity of {delta}T/T{approx}1{mu}K and a beam of 3{sup '}. These limits translate into a lower bound on the mass of the DM particle, M{sub DM}>10-100 GeV, assuming a single species with a cross section of <{sigma}{sub A}v>{approx}2x10{sup -26} cm{sup 3}/s, and a fraction f{approx}0.1-1 of the rest mass energy used

  9. Non-Gaussianity and CMB aberration and Doppler

    SciTech Connect (OSTI)

    Catena, Riccardo; Liguori, Michele; Renzi, Alessandro; Notari, Alessio E-mail: michele.liguori@pd.infn.it E-mail: arenzi@pd.infn.it

    2013-09-01

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

  10. Testing the Lorentz and CPT symmetry with CMB polarizations and a non-relativistic Maxwell theory

    SciTech Connect (OSTI)

    Cai, Yi-Fu; Zhang, Xinmin; Li, Mingzhe E-mail: limz@nju.edu.cn

    2010-01-01

    We present a model for a system involving a photon gauge field and a scalar field at quantum criticality in the frame of a Lifthitz-type non-relativistic Maxwell theory. We will show this model gives rise to Lorentz and CPT violation which leads to a frequency-dependent rotation of polarization plane of radiations, and so leaves potential signals on the cosmic microwave background temperature and polarization anisotropies.

  11. Correlation function analysis of the COBE differential microwave radiometer sky maps

    SciTech Connect (OSTI)

    Lineweaver, C.H.

    1994-08-01

    The Differential Microwave Radiometer (DMR) aboard the COBE satellite has detected anisotropies in the cosmic microwave background (CMB) radiation. A two-point correlation function analysis which helped lead to this discovery is presented in detail. The results of a correlation function analysis of the two year DMR data set is presented. The first and second year data sets are compared and found to be reasonably consistent. The positive correlation for separation angles less than {approximately}20{degree} is robust to Galactic latitude cuts and is very stable from year to year. The Galactic latitude cut independence of the correlation function is strong evidence that the signal is not Galactic in origin. The statistical significance of the structure seen in the correlation function of the first, second and two year maps is respectively > 9{sigma}, > 10{sigma} and > 18{sigma} above the noise. The noise in the DMR sky maps is correlated at a low level. The structure of the pixel temperature covariance matrix is given. The noise covariance matrix of a DMR sky map is diagonal to an accuracy of better than 1%. For a given sky pixel, the dominant noise covariance occurs with the ring of pixels at an angular separation of 60{degree} due to the 60{degree} separation of the DMR horns. The mean covariance of 60{degree} is 0.45%{sub {minus}0.14}{sup +0.18} of the mean variance. The noise properties of the DMR maps are thus well approximated by the noise properties of maps made by a single-beam experiment. Previously published DMR results are not significantly affected by correlated noise.

  12. Analysing the Effect on CMB in a Parity and Charge Parity Violating...

    Office of Scientific and Technical Information (OSTI)

    Varying Alpha Theory Citation Details In-Document Search Title: Analysing the Effect on CMB in a Parity and Charge Parity Violating Varying Alpha Theory In this paper we ...

  13. Oscillations in the CMB from Axion Monodromy Inflation

    SciTech Connect (OSTI)

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

    2011-12-01

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

  14. High brightness microwave lamp

    DOE Patents [OSTI]

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

    2003-09-09

    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.

  15. Microwave hemorrhagic stroke detector

    DOE Patents [OSTI]

    Haddad, Waleed S.; Trebes, James E.

    2007-06-05

    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.

  16. Microwave hemorrhagic stroke detector

    DOE Patents [OSTI]

    Haddad, Waleed S.; Trebes, James E.

    2002-01-01

    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.

  17. The cosmic microwave background after MAXIMA and BOOMERANG

    SciTech Connect (OSTI)

    Richards, Paul L.

    2000-12-01

    The first release of data from the MAXIMA and BOOMERANG experiments has introduced a new era of precision cosmology. The two data sets are essentially independent, consistent and complementary. In a joint effort by the two teams, the two data sets were combined and then used to test cosmological models and determine values of cosmological constants. These results are available because of the success of bolometric detection techniques. The experimental approach is described with references to the MAXIMA-1 experiment. Important new cosmological experiments at far infrared and millimeter wavelengths require major improvements in bolometric techniques. A new technology, the voltage-biased superconducting bolometer, promises to provide the required experimental power.

  18. A MEASUREMENT OF SECONDARY COSMIC MICROWAVE BACKGROUND ANISOTROPIES...

    Office of Scientific and Technical Information (OSTI)

    ... (United States) Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada) Department of Astrophysical and Planetary Sciences and Department of Physics, ...

  19. Constraints on cosmology from the cosmic microwave background...

    Office of Scientific and Technical Information (OSTI)

    ... of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada) Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, ...

  20. Variable frequency microwave heating apparatus

    DOE Patents [OSTI]

    Bible, Don W.; Lauf, Robert J.; Johnson, Arvid C.; Thigpen, Larry T.

    1999-01-01

    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).

  1. Microwave ion source

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Reijonen, Jani; Thomae, Rainer W.

    2005-07-26

    A compact microwave ion source has a permanent magnet dipole field, a microwave launcher, and an extractor parallel to the source axis. The dipole field is in the form of a ring. The microwaves are launched from the middle of the dipole ring using a coaxial waveguide. Electrons are heated using ECR in the magnetic field. The ions are extracted from the side of the source from the middle of the dipole perpendicular to the source axis. The plasma density can be increased by boosting the microwave ion source by the addition of an RF antenna. Higher charge states can be achieved by increasing the microwave frequency. A xenon source with a magnetic pinch can be used to produce intense EUV radiation.

  2. Microwave coupler and method

    DOE Patents [OSTI]

    Holcombe, C.E.

    1984-11-29

    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.

  3. Microwave thawing apparatus and method

    SciTech Connect (OSTI)

    Fathi, Zakaryae; Lauf, Robert J.; McMillan, April D.

    2004-06-01

    An apparatus for thawing a frozen material includes: a microwave energy source; a microwave applicator which defines a cavity for applying microwave energy from the microwave source to a material to be thawed; and a shielded region which is shielded from the microwave source, the shielded region in fluid communication with the cavity so that thawed material may flow from the cavity into the shielded region.

  4. COLLOQUIUM: Seeing the Big Bang More Clearly: The Evolution of

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

    Observational Techniques in CMB Studies | Princeton Plasma Physics Lab October 28, 2015, 4:00pm to 5:30pm Colloquia MBG AUDITORIUM COLLOQUIUM: Seeing the Big Bang More Clearly: The Evolution of Observational Techniques in CMB Studies Professor Bruce Partridge Haverford College Since 2015 marks the fiftieth anniversary of the discovery of the cosmic microwave background (CMB), I will begin by analyzing the very early experiments that established the properties of the CMB. What experimental

  5. Microwave fluid flow meter

    DOE Patents [OSTI]

    Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.

    1976-01-01

    A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

  6. Emitron: microwave diode

    DOE Patents [OSTI]

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

    1982-05-06

    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.

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

    SciTech Connect (OSTI)

    Gmez-Cadenas, J.J.; Martn-Albo, J.; Vidal, J. Muoz; Pea-Garay, C., E-mail: gomez@mail.cern.ch, E-mail: jmalbos@ific.uv.es, E-mail: jmunoz@ific.uv.es, E-mail: penya@ific.uv.es [Instituto de Fsica Corpuscular (IFIC), CSIC and Universitat de Valencia Calle Catedrtico Jos Beltrn, 2, 46090 Paterna, Valencia (Spain)

    2013-03-01

    The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with ?m{sub ?} = (0.320.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ??} involved in neutrinoless double beta decay (??0?) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ??0? experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kgyear, could already have a sizeable opportunity to observe ??0? events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 tonyear, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.

  8. High power microwave generator

    DOE Patents [OSTI]

    Ekdahl, Carl A.

    1986-01-01

    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.

  9. High power microwave generator

    DOE Patents [OSTI]

    Ekdahl, C.A.

    1983-12-29

    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.

  10. Planck CMB anomalies: astrophysical and cosmological secondary effects and the curse of masking

    SciTech Connect (OSTI)

    Rassat, A.; Starck, J.-L.; Paykari, P.; Sureau, F.; Bobin, J. E-mail: jstarck@cea.fr E-mail: florent.sureau@cea.fr

    2014-08-01

    Large-scale anomalies have been reported in CMB data with both WMAP and Planck data. These could be due to foreground residuals and or systematic effects, though their confirmation with Planck data suggests they are not due to a problem in the WMAP or Planck pipelines. If these anomalies are in fact primordial, then understanding their origin is fundamental to either validate the standard model of cosmology or to explore new physics. We investigate three other possible issues: 1) the trade-off between minimising systematics due to foreground contamination (with a conservative mask) and minimising systematics due to masking, 2) astrophysical secondary effects (the kinetic Doppler quadrupole and kinetic Sunyaev-Zel'dovich effect), and 3) secondary cosmological signals (the integrated Sachs-Wolfe effect). We address the masking issue by considering new procedures that use both WMAP and Planck to produce higher quality full-sky maps using the sparsity methodology (LGMCA maps). We show the impact of masking is dominant over that of residual foregrounds, and the LGMCA full-sky maps can be used without further processing to study anomalies. We consider four official Planck PR1 and two LGMCA CMB maps. Analysis of the observed CMB maps shows that only the low quadrupole and quadrupole-octopole alignment seem significant, but that the planar octopole, Axis of Evil, mirror parity and cold spot are not significant in nearly all maps considered. After subtraction of astrophysical and cosmological secondary effects, only the low quadrupole may still be considered anomalous, meaning the significance of only one anomaly is affected by secondary effect subtraction out of six anomalies considered. In the spirit of reproducible research all reconstructed maps and codes will be made available for download here http://www.cosmostat.org/anomaliesCMB.html.

  11. 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 ...

  12. LTS Background - Hanford Site

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

    Background About Us Hanford Cultural Resources LTS Home Page LTS Project Management LTS Transition and Timeline LTS Execution LTS Background LTS Information Management LTS Fact Sheets / Briefings LTS In The News LTS Related Links LTS Contact Us LTS Background Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size DOE recognized the significance of LTS in the 1990's when it issued several reports that addressed cleanup and management of land upon completion of the

  13. Extragalactic Background Light

    Office of Scientific and Technical Information (OSTI)

    Extragalactic Background Light from Hierarchical Galaxy Formation: Gamma-ray Attenuation up to the Epoch of Cosmic Reionization and the First Stars Yoshiyuki Inoue 1 , Susumu Inoue...

  14. High power microwave generator

    DOE Patents [OSTI]

    Minich, Roger W.

    1988-01-01

    A device (10) for producing high-powered and coherent microwaves is described. The device comprises an evacuated, cylindrical, and hollow real cathode (20) that is driven to inwardly field emit relativistic electrons. The electrons pass through an internally disposed cylindrical and substantially electron-transparent cylindrical anode (24), proceed toward a cylindrical electron collector electrode (26), and form a cylindrical virtual cathode (32). Microwaves are produced by spatial and temporal oscillations of the cylindrical virtual cathode (32), and by electrons that reflex back and forth between the cylindrical virtual cathode (32) and the cylindrical real cathode (20).

  15. Variable frequency microwave furnace system

    DOE Patents [OSTI]

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

    1994-06-14

    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.

  16. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, Don W.; Lauf, Robert J.

    1994-01-01

    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).

  17. A large scale coherent magnetic field: interactions with free streaming particles and limits from the CMB

    SciTech Connect (OSTI)

    Adamek, Julian; Durrer, Ruth; Fenu, Elisa; Vonlanthen, Marc E-mail: ruth.durrer@unige.ch E-mail: marc.vonlanthen@unige.ch

    2011-06-01

    We study a homogeneous and nearly-isotropic Universe permeated by a homogeneous magnetic field. Together with an isotropic fluid, the homogeneous magnetic field, which is the primary source of anisotropy, leads to a plane-symmetric Bianchi I model of the Universe. However, when free-streaming relativistic particles are present, they generate an anisotropic pressure which counteracts the one from the magnetic field such that the Universe becomes isotropized. We show that due to this effect, the CMB temperature anisotropy from a homogeneous magnetic field is significantly suppressed if the neutrino masses are smaller than 0.3 eV.

  18. ARM - Methane Background Information

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

    WarmingMethane Background Information Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Methane Background Information What is Methane? Why Do We Use Methane? How is Methane Made? Where Do We Find Methane? Can Methane Be Dangerous? Does Methane Contribute to Climate Change? What is Methane?

  19. Scientific results from the cosmic background explorer (COBE). [Information on cosmic radiation

    SciTech Connect (OSTI)

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

    1993-06-01

    The National Aeronautics and Space Administration (NASA) has flown the COBE satellite to observe the Big Bang and the subsequent formation of galaxies and large-scale structure. Data from the Far-Infrared Absolute Spectrophotometer (FIRAS) show that the spectrum of the cosmic microwave background is that of a black body of temperature T = 2.73 [+-] 0.06 K, with no deviation from a black-body spectrum greater than 0.25% of the peak brightness. The data from the Differential Microwave Radiometers (DMR) show statistically significant cosmic microwave background anisotropy, consistent with a scale-invariant primordial density fluctuation spectrum. Measurements from the Diffuse Infrared Background Experiment (DIRBE) provide new conservation upper limits to the cosmic infrared background. Extensive modeling of solar system and galactic infrared foregrounds is required for further improvement in the cosmic infrared background limits. 104 refs., 1 tab.

  20. Innovative Microwave Technology - Energy Innovation Portal

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

    Advanced Materials Advanced Materials Return to Search Innovative Microwave Technology Hybrid microwave technology capable of performing functions that traditional microwave systems could not achieve. Savannah River National Laboratory New Hybrid Microwave Technology New Hybrid Microwave Technology Success Story Details Partner Location Agreement Type Publication Date Hadron Technologies, Inc. Offices in Tennessee and Colorado License October 22, 2013 Summary Hadron Technologies, Inc. has signed

  1. Microwave solidification project overview

    SciTech Connect (OSTI)

    Sprenger, G.

    1993-01-01

    The Rocky Flats Plant Microwave Solidification Project has application potential to the Mixed Waste Treatment Project and the The Mixed Waste Integrated Program. The technical areas being addressed include (1) waste destruction and stabilization; (2) final waste form; and (3) front-end waste handling and feed preparation. This document covers need for such a program; technology description; significance; regulatory requirements; and accomplishments to date. A list of significant reports published under this project is included.

  2. High Energy Density Microwaves

    SciTech Connect (OSTI)

    Phillips, R.M. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)

    1999-04-01

    These proceedings represent papers presented at the RF98 Workshop entitled `High Energy Density Microwaves` held in California in October, 1998. The topics discussed were predominantly accelerator{minus}related. The Workshop dealt, for the most part, with the generation and control of electron beams, the amplification of RF signals, the design of mode converters, and the effect of very high RF field gradients. This Workshop was designed to address the concerns of the microwave tube industry worldwide, the plasma physicists who deal with very high beam currents and gigawatts of RF power, and researchers in accelerator centers around the world. Papers were presented on multibeam klystrons, gyrotron development, plasmas in microwave tubes, RF breakdown, and alternatives to conventional linear coliders at 1 TeV and above. The Workshop was partially sponsored by the US Department of Energy. There were 46 papers presented at the conference,out of which 19 have been abstracted for the Energy,Science and Technology database.(AIP)

  3. Berkeley Low Background Facility

    SciTech Connect (OSTI)

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  4. EM SSAB Funding Background

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

    Funding Background The Environmental Management Site Specific Advisory Board (EM SSAB), comprises 200+ individuals from eight regional Advisory Boards from Georgia, Idaho, Kentucky, Nevada, New Mexico, Ohio, Oregon, South Carolina, Tennessee and Washington. These Advisory Boards cumulatively represent a stakeholder population of millions of people affected by waste generator sites, transportation routes, and waste disposal areas. EM SSAB members commit their time and resources as volunteers to

  5. More About Inversions Background

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

    About Inversions Background Inversions occur in fluids when a more dense fluid lies beneath a less dense fluid. In the atmosphere, the density is linked to temperature variations with warmer air lying atop colder air. Sounding Analysis - Inversions (Activity) Objective To evaluate radiosonde soundings for inversions. Materials  Soundings for the same date and synoptic time (provided or obtained online) Important Points to Understand The soundings here appear on a Stuve diagram. Because the

  6. Polarization of the cosmic background radiation

    SciTech Connect (OSTI)

    Lubin, P.M.

    1980-03-01

    The results and technique of a measurement of the linear polarization of the Cosmic Background Radiation are discussed. The ground-based experiment utilizes a single horn (7/sup 0/ beam width) Dicke-type microwave polarimeter operating at 33 GHz (9.1 mm). Data taken between May 1978 and February 1980 from both the northern hemisphere (Berkeley Lat. = 38/sup 0/N) and the southern hemisphere (Lima Lat. = 12/sup 0/S) show the radiation to be essentially unpolarized over all areas surveyed. For the 38/sup 0/ declination data the 95% confidence level limit on a linearly polarized component is 0.3 mK for the average and 12 and 24 hour periods. Fitting all data gives the 95% confidence level limit on a linearly polarized component of 0.3 mK for spherical harmonics through third order. Constraints on various cosmological models are discussed in light of these limits.

  7. Microwave sintering of multiple articles

    DOE Patents [OSTI]

    Blake, Rodger D.; Katz, Joel D.

    1993-01-01

    Apparatus and method for producing articles of alumina and of alumina and silicon carbide in which the articles are sintered at high temperatures using microwave radiation. The articles are placed in a sintering container which is placed in a microwave cavity for heating. The rates at which heating and cooling take place is controlled.

  8. Ionizing radiation from hydrogen recombination strongly suppresses the lithium scattering signature in the CMB

    SciTech Connect (OSTI)

    Switzer, Eric R.; Hirata, Christopher M.

    2005-10-15

    It has been suggested that secondary CMB anisotropies generated by neutral lithium could open a new observational window into the universe around the redshift z{approx}400, and permit a determination of the primordial lithium abundance. The effect is due to resonant scattering in the allowed Li i doublet (2s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 1/2,3/2}), so its observability depends on the formation history of neutral lithium. Here we show that the ultraviolet photons produced during hydrogen recombination are sufficient to keep lithium in the Li ii ionization stage in the relevant redshift range and suppress the neutral fraction by {approx}3 orders of magnitude from previous calculations, making the lithium signature unobservable.

  9. Microwave hematoma detector

    DOE Patents [OSTI]

    Haddad, Waleed S.; Trebes, James E.; Matthews, Dennis L.

    2001-01-01

    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.

  10. Microwave-driven ultraviolet light sources

    DOE Patents [OSTI]

    Manos, Dennis M.; Diggs, Jessie; Ametepe, Joseph D.

    2002-01-29

    A microwave-driven ultraviolet (UV) light source is provided. The light source comprises an over-moded microwave cavity having at least one discharge bulb disposed within the microwave cavity. At least one magnetron probe is coupled directly to the microwave cavity.

  11. Gigatron microwave amplifier

    DOE Patents [OSTI]

    McIntyre, P.M.

    1993-07-13

    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.

  12. Gigatron microwave amplifier

    DOE Patents [OSTI]

    McIntyre, Peter M.

    1993-01-01

    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.

  13. DNA sequencing using fluorescence background electroblotting membrane

    DOE Patents [OSTI]

    Caldwell, K.D.; Chu, T.J.; Pitt, W.G.

    1992-05-12

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings

  14. DNA sequencing using fluorescence background electroblotting membrane

    DOE Patents [OSTI]

    Caldwell, Karin D.; Chu, Tun-Jen; Pitt, William G.

    1992-01-01

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to said target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membrances may be reprobed numerous times.

  15. 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 ...

  16. ANOMALOUS ANISOTROPIC CROSS-CORRELATIONS BETWEEN WMAP CMB MAPS AND SDSS GALAXY DISTRIBUTION AND IMPLICATIONS ON THE DARK FLOW SCENARIO

    SciTech Connect (OSTI)

    Li Zhigang; Chen Xuelei; Zhang Pengjie E-mail: pjzhang@shao.ac.cn

    2012-10-20

    We search for the dark flow induced diffuse kinetic Sunyaev-Zel'dovich (kSZ) effect through CMB-galaxy cross-correlation. Such angular correlation is anisotropic, with a unique cos ({theta}{sub DF}) angular dependence, and hence can be distinguished from other components. Here, {theta}{sub DF} is the angle between the opposite dark flow direction and the direction of the sky where the correlation is measured. We analyze the KIAS-VAGC galaxy catalog of SDSS-DR7 and the WMAP seven-year temperature maps, applying an unbiased optimal weighting scheme to eliminate any statistically isotropic components and to enhance the dark flow detection signal. Non-zero weighted cross-correlations are detected at 3.5 {sigma} for the redshift bin z < 0.1 and at 3 {sigma} for the bin 0.1 < z < 0.2, implying the existence of statistically anisotropic components in CMB. However, further analysis does not support the dark flow explanation. The observed directional dependence deviates from the {proportional_to}cos {theta}{sub DF} relation expected, and hence cannot be explained by the presence of a single dark flow, and if the observed cross-correlation is generated by the dark flow induced kSZ effect, the velocity would be too high ({approx}> 6000 km s{sup -1}). We report this work as the first attempt to search for dark flow through weighted CMB-galaxy cross-correlation and to draw the attention on the sources of the detected anomalous CMB-galaxy cross-correlation.

  17. North-South non-Gaussian asymmetry in Planck CMB maps

    SciTech Connect (OSTI)

    Bernui, A.; Oliveira, A.F.; Pereira, T.S. E-mail: adhimar@unifei.edu.br

    2014-10-01

    We report the results of a statistical analysis performed with the four foreground-cleaned Planck maps by means of a suitably defined local-variance estimator. Our analysis shows a clear dipolar structure in Planck's variance map pointing in the direction (l,b)?(220,-32), thus consistent with the North-South asymmetry phenomenon. Surprisingly, and contrary to previous findings, removing the CMB quadrupole and octopole makes the asymmetry stronger. Our results show a maximal statistical significance, of 98.1% CL, in the scales ranging from ?=4 to ?=500. Additionally, through exhaustive analyses of the four foreground-cleaned and individual frequency Planck maps, we find unlikely that residual foregrounds could be causing this dipole variance asymmetry. Moreover, we find that the dipole gets lower amplitudes for larger masks, evidencing that most of the contribution to the variance dipole comes from a region near the galactic plane. Finally, our results are robust against different foreground cleaning procedures, different Planck masks, pixelization parameters, and the addition of inhomogeneous real noise.

  18. Microwave heating apparatus and method

    DOE Patents [OSTI]

    Johnson, Andrew J.; Petersen, Robert D.; Swanson, Stephen D.

    1990-01-01

    An apparatus is provided for heating and melting materials using microwave energy, and for permitting them to solidify. The apparatus includes a microwave energy source, a resonant cavity having an opening in its floor, a microwave energy choke encompassing the opening in the floor of the cavity, a metal container to hold the materials to be heated and melted, a turntable, and a lift-table. During operation, the combined action of the turntable and the lift-table position the metal container so that the top of the container is level with the floor of the cavity, is in substantial registration with the floor opening, and is encompassed by the microwave energy choke; thus, during operation, the interior of the container defines part of the resonant cavity. Additionally, a screw feeder, extending into the cavity and sheltered from microwave energy by a conveyor choke, may convey the materials to be heated to the container. Also, preferably, the floor of the resonant cavity may include perforatins, so that the offgases and dust generated in the apparatus may be removed from the resonant cavity by pulling outside air between the container choke and the exterior wall of the container into the resonant cavity and out from the cavity through the perforations.

  19. SLAC All Access: Vacuum Microwave Device Department

    ScienceCinema (OSTI)

    Haase, Andy

    2014-06-13

    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.

  20. Search for Linear Polarization of the Cosmic Background Radiation

    DOE R&D Accomplishments [OSTI]

    Lubin, P. M.; Smoot, G. F.

    1978-10-01

    We present preliminary measurements of the linear polarization of the cosmic microwave background (3 deg K blackbody) radiation. These ground-based measurements are made at 9 mm wavelength. We find no evidence for linear polarization, and set an upper limit for a polarized component of 0.8 m deg K with a 95% confidence level. This implies that the present rate of expansion of the Universe is isotropic to one part in 10{sup 6}, assuming no re-ionization of the primordial plasma after recombination

  1. Ignition methods and apparatus using microwave energy

    DOE Patents [OSTI]

    DeFreitas, Dennis M.; Darling, Timothy W.; Migliori, Albert; Rees, Daniel E.

    1997-01-01

    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.

  2. Microwavable thermal energy storage material

    DOE Patents [OSTI]

    Salyer, I.O.

    1998-09-08

    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.

  3. Microwavable thermal energy storage material

    DOE Patents [OSTI]

    Salyer, Ival O.

    1998-09-08

    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.

  4. Background

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

    AGENCY RECORD OF DECISION: AMENDMENT NO. 1 TO FIRM POWER SALES AGREEMENT WITH PORT TOWNSEND PAPER CORPORATION, CONTRACT NO. 11PB-12330 AUTHENTICATED June 28, 2012 TABLE OF CONTENTS...

  5. Background

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

    technology, all of which support its national security mission. Sandia & EMCORE Solar Photovoltaics, Fiber Optics, MODE, and Energy Efficiency S a n d i a S t r a t e g i c P a...

  6. Background

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

    the establishment of the Nevada Test Site (now known as the Nevada National Security Site - NNSS) in 1951, thousands of people from around the world continue to visit this vast outdoor laboratory. Larger than the state of Rhode Island, the site features artifacts and archaeological sites from the early settlers, as well as the many relics remaining from nuclear weapons tests, nuclear rocket experiments, and a variety of other defense, environmental, and energy-related programs. Taking a Tour The

  7. Background

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

    and hydrogen-powered fuel cells offer an attractive alternative to current technologies. However, fuel cell catalysts ... inexpensive before they are practical and cost-effective. ...

  8. Background

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

    marketing and operating arrangement efforts. Flexible contracts responding to the pricing and unbundling forces emerging with the opening of the wholesale power market will...

  9. Background

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

    Data, and Approach Used in the EBT for the Amendment ... 1 b. IP Rate and Revenue Forecast Used in the EBT for the Amendment ... 2 c. BPA expects to have...

  10. Background

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

    ... 5 2. The Agreement will guarantee a revenue stream based on the IP rate, the statutorily defined rate for DSI sales....

  11. Background

    Office of Legacy Management (LM)

    including the mill tailings, were removed from the site and used in construction. ... During construction of the repository, visible dust cannot exceed State of Utah standards. ...

  12. Background

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

    by large bluff bodies upstream of the turbine, e.g. piers, commonly found in river and tidal channels. Vincent S. Neary, Ph.D., P. E. Email: nearyvs@ornl.gov http:...

  13. Background

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

    MODE technology was based on Sandia-licensed compound semiconductors used in manufacturing vertical cavity surface- emitting laser components. Upon acquiring MODE, EMCORE became ...

  14. BACKGROUND

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

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

  15. Background:

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

    TABLE OF CONTENTS Recommended Browsers for iSupplier Portal Recommended Microsoft Internet Explorer Browser Settings (MSIE) Recommended Firefox Browser Settings Recommended...

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

    SciTech Connect (OSTI)

    Quartin, Miguel [Instituto de Fsica, Universidade Federal do Rio de Janeiro, 21941-972, Rio de Janeiro, RJ (Brazil); Notari, Alessio, E-mail: mquartin@if.ufrj.br, E-mail: notari@ffn.ub.es [Departament de Fsica Fondamental i Institut de Cincies del Cosmos, Universitat de Barcelona, Mart i Franqus 1, E-08028 Barcelona (Spain)

    2015-01-01

    We perform an analysis of the CMB temperature data taken by the Planck satellite investigating if there is any significant deviation from cosmological isotropy. We look for differences in the spectrum between two opposite hemispheres and also for dipolar modulations. We propose a new way to avoid biases due to partial-sky coverage by producing a mask symmetrized in antipodal directions, in addition to the standard smoothing procedure. We also properly take into account both Doppler and aberration effects due to our peculiar velocity and the anisotropy of the noise, since these effects induce a significant hemispherical asymmetry. We are thus able to probe scales all the way to ?=2000. After such treatment we find no evidence for significant hemispherical anomalies along any of the analyzed directions (i.e. deviations are less than 1.5? when summing over all scales). Although among the larger scales there are sometimes higher discrepancies, these are always less than 3?. We also find results on a dipolar modulation of the power spectrum. Along the hemispheres aligned with the most asymmetric direction for 2???2000 we find a 3.3? discrepancy when comparing to simulations. However, if we do not restrict ourselves to Planck's maximal asymmetry axis, which can only be known a posteriori, and compare Planck data with the modulation of simulations along their respective maximal asymmetry directions, the discrepancy goes down to less than 1? (with, again, almost 3? discrepancies in some low-? modes). We thus conclude that no significant power asymmetries seem to be present in the full data set. Interestingly, without proper removal of Doppler and aberration effects one would find spurious anomalies at high ?, between 3? and 5?. Even when considering only ?<600 we find that the boost is non-negligible and alleviates the discrepancy by roughly half-?.

  17. Microwave assisted centrifuge and related methods

    DOE Patents [OSTI]

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

    2010-08-17

    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.

  18. Microwave treatment of vulcanized rubber

    DOE Patents [OSTI]

    Wicks, George G.; Schulz, Rebecca L.; Clark, David E.; Folz, Diane C.

    2002-07-16

    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.

  19. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

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

    1998-08-25

    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.

  20. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

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

    1998-09-08

    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.

  1. Scanning tip microwave near field microscope

    DOE Patents [OSTI]

    Xiang, Xiao-Dong; Schultz, Peter G.; Wei, Tao

    1998-01-01

    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.

  2. Scanning tip microwave near field microscope

    DOE Patents [OSTI]

    Xiang, X.D.; Schultz, P.G.; Wei, T.

    1998-10-13

    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 end wall 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. 17 figs.

  3. Adhesive bonding using variable frequency microwave energy

    DOE Patents [OSTI]

    Lauf, Robert J.; McMillan, April D.; Paulauskas, Felix L.; Fathi, Zakaryae; Wei, Jianghua

    1998-01-01

    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.

  4. Satellite remote sensing of global rainfall using passive microwave radiometry

    SciTech Connect (OSTI)

    Ferriday, J.G.

    1994-12-31

    Global rainfall over land and ocean is estimated using measurements of upwelling microwaves by a satellite passive microwave radiometer. Radiative transfer calculations through a cloud model are used to parameterize an inversion technique for retrieving rain rates from brightness temperatures measured by the Special Sensor Microwave Imager (SSM/I). The rainfall retrieval technique is based on the interaction between multi-spectral microwave radiances and millimeter sized liquid and frozen hydrometeors distributed in the satellite`s field of view. The rain rate algorithm is sensitive to both hydrometeor emission and scattering while being relatively insensitive to extraneous atmospheric and surface effects. Separate formulations are used over ocean and land to account for different background microwave characteristics and the algorithm corrects for inhomogeneous distributions of rain rates within the satellite`s field of view. Estimates of instantaneous and climate scale rainfall are validated through comparisons with modeled clouds, surface radars, rain gauges and alternative satellite estimates. The accuracy of the rainfall estimates is determined from a combination of validation comparisons, theoretical sampling error calculations, and modeled sensitivity to variations in atmospheric and surface radiative properties. An error budget is constructed for both instantaneous rain rates and climate scale global estimates. At a one degree resolution, the root mean square errors in instantaneous rain rate estimates are 13% over ocean and 20% over land. The root mean square errors in global rainfall totals over a four month period are found to be 46% over ocean and 63% over land. Global rainfall totals are computed on a monthly scale for a three year period from 1987 to 1990. The time series is analyzed for climate scale rainfall distribution and variability.

  5. Controlled zone microwave plasma system

    SciTech Connect (OSTI)

    Ripley, Edward B; Seals, Roland D; Morrell, Jonathan S

    2009-10-20

    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.

  6. Microwave sintering of boron carbide

    DOE Patents [OSTI]

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

    1988-06-10

    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.

  7. COLLOQUIUM: Probing the History and Dynamics of the Universe with Polarized

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

    Signatures in the Cosmic Microwave Background | Princeton Plasma Physics Lab September 23, 2015, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Probing the History and Dynamics of the Universe with Polarized Signatures in the Cosmic Microwave Background Professor Suzane Staggs Princeton University Presentation: PDF icon WC23SEP2015SStaggs.pdf The cosmic microwave background (CMB) radiation reports the initial conditions in the universe for the formation of large scale structures

  8. Background estimation in experimental spectra

    SciTech Connect (OSTI)

    Fischer, R.; Hanson, K. M.; Los Alamos National Laboratory, MS P940, Los Alamos, New Mexico 87545 ; Dose, V.; Linden, W. von der

    2000-02-01

    A general probabilistic technique for estimating background contributions to measured spectra is presented. A Bayesian model is used to capture the defining characteristics of the problem, namely, that the background is smoother than the signal. The signal is allowed to have positive and/or negative components. The background is represented in terms of a cubic spline basis. A variable degree of smoothness of the background is attained by allowing the number of knots and the knot positions to be adaptively chosen on the basis of the data. The fully Bayesian approach taken provides a natural way to handle knot adaptivity and allows uncertainties in the background to be estimated. Our technique is demonstrated on a particle induced x-ray emission spectrum from a geological sample and an Auger spectrum from iron, which contains signals with both positive and negative components. (c) 2000 The American Physical Society.

  9. The cross correlation between the 21-cm radiation and the CMB lensing field: a new cosmological signal

    SciTech Connect (OSTI)

    Vallinotto, Alberto

    2011-01-01

    The measurement of Baryon Acoustic Oscillations through the 21-cm intensity mapping technique at redshift z {<=} 4 has the potential to tightly constrain the evolution of dark energy. Crucial to this experimental effort is the determination of the biasing relation connecting fluctuations in the density of neutral hydrogen (HI) with the ones of the underlying dark matter field. In this work I show how the HI bias relevant to these 21-cm intensity mapping experiments can successfully be measured by cross-correlating their signal with the lensing signal obtained from CMB observations. In particular I show that combining CMB lensing maps from Planck with 21-cm field measurements carried out with an instrument similar to the Cylindrical Radio Telescope, this cross-correlation signal can be detected with a signal-to-noise (S/N) ratio of more than 5. Breaking down the signal arising from different redshift bins of thickness {Delta}z = 0.1, this signal leads to constraining the large scale neutral hydrogen bias and its evolution to 4{sigma} level.

  10. Paducah Background | Department of Energy

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

    Background Paducah Background Click image for interactive historical timeline of the Paducah Site. Click image for interactive historical timeline of the Paducah Site. In October 1950, the United States Atomic Energy Commission selected a former World War II munitions plant near Paducah, Kentucky, known as Kentucky Ordnance Works, as the site for the second of three planned uranium enrichment plants in the United States. The other two enrichment plants were located near Portsmouth, Ohio and Oak

  11. BEDES Background | Department of Energy

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

    Background BEDES Background The Building Energy Data Exchange Specification data dictionary is a response to the need for a standardized system of terms and definitions for building energy performance data. By providing a set of common terms and definitions, BEDES will provide the framework on which to build interoperable data schemas and software tools which reduce the time and expense currently invested in sharing data. HISTORY BEDES was originally developed for internal use to improve

  12. Low Background Counting at LBNL

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

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K)more » or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.« less

  13. Low Background Counting at LBNL

    SciTech Connect (OSTI)

    Smith, A. R.; Thomas, K. J.; Norman, E. B.; Chan, Y. D.; Lesko, K. T.; Hurley, D. L.

    2015-03-24

    The Low Background Facility (LBF) at Lawrence Berkeley National Laboratory in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background cave and remotely at an underground location that historically has operated underground in Oroville, CA, but has recently been relocated to the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products, as well as active screening via Neutron Activation Analysis for specific applications. The LBF also provides hosting services for general R&D testing in low background environments on the surface or underground for background testing of detector systems or similar prototyping. A general overview of the facilities, services, and sensitivities is presented. Recent activities and upgrades will also be presented, such as the completion of a 3π anticoincidence shield at the surface station and environmental monitoring of Fukushima fallout. The LBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  14. Microwave-enhanced chemical processes

    DOE Patents [OSTI]

    Varma, Ravi

    1990-01-01

    A process for disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Effecting intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400.degree. C. in the presence of microwave radiation for a time sufficient to break the hydrocarbon chlorine bonds and provide detoxification values in excess of 80 and further detoxifying the bed followed by additional disposal of toxic wastes.

  15. Microwave assisted hard rock cutting

    DOE Patents [OSTI]

    Lindroth, David P.; Morrell, Roger J.; Blair, James R.

    1991-01-01

    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).

  16. ARM - Field Campaign - Microwave Radiometer Profiler Evaluation

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

    govCampaignsMicrowave Radiometer Profiler Evaluation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Microwave Radiometer Profiler Evaluation 2000.09.01 - 2001.03.31 Lead Scientist : James Liljegren For data sets, see below. Abstract The microwave radiometer profiler (MWRP) is a new 12-channel radiometer developed by Radiometrics Corporation for measuring vertical profiles of temperature, water vapor, and

  17. ARM - Field Campaign - Microwave Radiometer Profiler Evaluation

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

    govCampaignsMicrowave Radiometer Profiler Evaluation ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Microwave Radiometer Profiler Evaluation 2000.02.25 - 2000.08.22 Lead Scientist : James Liljegren For data sets, see below. Abstract The microwave radiometer profiler (MWRP) is a new 12-channel radiometer developed by Radiometrics Corporation for measuring vertical profiles of temperature, water vapor, and

  18. Microwave solidification development for Rocky Flats waste

    SciTech Connect (OSTI)

    Dixon, D.; Erle, R.; Eschen, V.

    1994-04-01

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

  19. Process for microwave sintering boron carbide

    DOE Patents [OSTI]

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

    1993-10-12

    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.

  20. Process for microwave sintering boron carbide

    DOE Patents [OSTI]

    Holcombe, Cressie E.; Morrow, Marvin S.

    1993-01-01

    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.

  1. ARM - Measurement - Microwave narrowband brightness temperature

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

    Radiometer - ETL MWRP : Microwave Radiometer Profiler MMWR : Millimeter Wave Radiometer MIR : Millimeter-wave Imaging Radiometer NOAA-P3 : NOAA P-3 Aircraft PARSL : PNNL's...

  2. Hybrid Microwave Energy - Energy Innovation Portal

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

    undesirable environmental consequences.Description The hybrid microwave system provides a simple processing method for the reduction of waste volume, immobilization of hazardous...

  3. Detector Background at Muon Colliders

    SciTech Connect (OSTI)

    Mokhov, N.V.; Striganov, S.I.; /Fermilab

    2011-09-01

    Physics goals of a Muon Collider (MC) can only be reached with appropriate design of the ring, interaction region (IR), high-field superconducting magnets, machine-detector interface (MDI) and detector. Results of the most recent realistic simulation studies are presented for a 1.5-TeV MC. It is shown that appropriately designed IR and MDI with sophisticated shielding in the detector have a potential to substantially suppress the background rates in the MC detector. The main characteristics of backgrounds are studied.

  4. The COBE Diffuse Infrared Background Experiment search for thecosmic infrared background. I. Limits and detections

    SciTech Connect (OSTI)

    Hauser, M.G.; Arendt, R.G.; Kelsall, T.; Dwek, E.; Odegard, N.; Weiland, J.L.; Freudenreich, H.T.; Reach, W.T.; Silverberg, R.F.; Moseley, S.H.; Pei, Y.C.; Lubin, P.; Mather, J.C.; Shafer, R.A.; Smoot,G.F.; Weiss, R.; Wilkinson, D.T.; Wright, E.L.

    1998-01-06

    The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer (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 l nu<64 nW m-2 sr-1, 95 percent confidence level) and at 240 mu m (nu l nu < 28 nW m-1 sr-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 mum 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 l nu = 25 +- 7 and 14 +- 3 nW m-2 sr-1 at 140 and 240 mu m, respectively. The integrated energy from 140 to 240 mu m, 10.3 nW m-2sr-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.

  5. ARM: Microwave Radiometer: High Frequency, calibration data for...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Microwave Radiometer: High Frequency, calibration data for 150GHz channel Microwave Radiometer: High Frequency, calibration data for 150GHz channel Authors: Maria ...

  6. ARM: Microwave Radiometer: High Frequency, calibration data for...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Microwave Radiometer: High Frequency, calibration data for 90GHz channel Microwave Radiometer: High Frequency, calibration data for 90GHz channel Authors: Maria Cadeddu ...

  7. A Linear Theory of Microwave Instability in Electron Storage...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: A Linear Theory of Microwave Instability in Electron Storage Rings Citation Details In-Document Search Title: A Linear Theory of Microwave Instability in Electron...

  8. Seeing through walls at the nanoscale: Microwave microscopy of...

    Office of Scientific and Technical Information (OSTI)

    Seeing through walls at the nanoscale: Microwave microscopy of enclosed objects and ... Title: Seeing through walls at the nanoscale: Microwave microscopy of enclosed objects and ...

  9. TM01-mode microwave propagation property analysis for plasmas...

    Office of Scientific and Technical Information (OSTI)

    Then electromagnetic fields of the TM01-mode microwave concentrate at the center surfaces ... EVALUATIONS; ELECTRIC FIELDS; ELECTROMAGNETIC FIELDS; ELECTRON DENSITY; MICROWAVE ...

  10. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies...

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

    Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced ...

  11. Modulated microwave microscopy and probes used therewith (Patent...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Modulated microwave microscopy and probes used therewith A microwave microscope including a probe tip electrode vertically positionable ...

  12. Product Standards for Microwaves (Japan) | Open Energy Information

    Open Energy Info (EERE)

    Microwaves (Japan) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Product Standards for Microwaves (Japan) Focus Area: Appliances & Equipment Topics: Policy Impacts...

  13. A Microwave Thruster for Spacecraft Propulsion (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: A Microwave Thruster for Spacecraft Propulsion Citation Details In-Document Search Title: A Microwave Thruster for Spacecraft Propulsion This presentation ...

  14. ARM: Microwave Radiometer Retrievals (MWRRET) of Cloud Liquid...

    Office of Scientific and Technical Information (OSTI)

    Microwave Radiometer Retrievals (MWRRET) of Cloud Liquid Water and Precipitable Water Vapor Title: ARM: Microwave Radiometer Retrievals (MWRRET) of Cloud Liquid Water and ...

  15. Microwave-enhanced chemical processes

    DOE Patents [OSTI]

    Varma, R.

    1990-06-19

    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.

  16. Microwave-triggered laser switch

    DOE Patents [OSTI]

    Piltch, Martin S.

    1984-01-01

    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.

  17. Microwave-triggered laser switch

    DOE Patents [OSTI]

    Piltch, M.S.

    1982-05-19

    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.

  18. Method of sintering materials with microwave radiation

    DOE Patents [OSTI]

    Kimrey, Jr., Harold D.; Holcombe, Jr., Cressie E.; Dykes, Norman L.

    1994-01-01

    A method of sintering ceramic materials following: A compacted article comprising inorganic particles coated with carbon is provided, the carbon providing improved microwave coupling. The compacted article is then heated by microwave radiation to a temperature and for a period of time sufficient to sinter the compacted article.

  19. Method of sintering materials with microwave radiation

    DOE Patents [OSTI]

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

    1994-06-14

    Disclosed is a method of sintering ceramic materials. A compacted article comprising inorganic particles coated with carbon is provided, the carbon providing improved microwave coupling. The compacted article is then heated by microwave radiation to a temperature and for a period of time sufficient to sinter the compacted article. No Drawings

  20. Remediated Nitrate Salt Drums Background

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

    Providing Additional Pressure Relief to the Remediated Nitrate Salt Drums Background After the radiological event on February 14, 2014 at the Waste Isolation Pilot Plant (WIPP), Department of Energy (DOE) scientists from several national laboratories conducted extensive experiments and modeling studies to determine what caused the drum to breach. These investigations indicated that an incompatible mixture of nitrate salts and an organic absorbent created the conditions that resulted in an

  1. The isotropic radio background revisited

    SciTech Connect (OSTI)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.

    2014-04-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  2. A Microwave Thruster for Spacecraft Propulsion

    SciTech Connect (OSTI)

    Chiravalle, Vincent P

    2012-07-23

    This presentation describes how a microwave thruster can be used for spacecraft propulsion. A microwave thruster is part of a larger class of electric propulsion devices that have higher specific impulse and lower thrust than conventional chemical rocket engines. Examples of electric propulsion devices are given in this presentation and it is shown how these devices have been used to accomplish two recent space missions. The microwave thruster is then described and it is explained how the thrust and specific impulse of the thruster can be measured. Calculations of the gas temperature and plasma properties in the microwave thruster are discussed. In addition a potential mission for the microwave thruster involving the orbit raising of a space station is explored.

  3. Tandem microwave waste remediation and decontamination system

    DOE Patents [OSTI]

    Wicks, George G.; Clark, David E.; Schulz, Rebecca L.

    1999-01-01

    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.

  4. Microwave drying of ferric oxide pellets

    SciTech Connect (OSTI)

    Pickles, C.A.; Xia, D.K.

    1997-12-31

    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.

  5. Microwaving of normally opaque and semi-opaque substances

    DOE Patents [OSTI]

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

    1990-07-17

    Disclosed is a method of heating small particles using microwave radiation which are not normally capable of being heated by microwaves. The surfaces of the particles are coated with a material which is transparent to microwave radiation in order to cause microwave coupling to the particles and thus accomplish heating of the particles.

  6. Microwaving of normally opaque and semi-opaque substances

    DOE Patents [OSTI]

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1990-01-01

    Method of heating small particles using microwave radiation which are not normally capable of being heated by microwaves. The surfaces of the particles are coated with a material which is transparent to microwave radiation in order to cause microwave coupling to the particles and thus accomplish heating of the particles.

  7. Low background aspects of GERDA

    SciTech Connect (OSTI)

    Simgen, Hardy

    2011-04-27

    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.

  8. Background canceling surface alpha detector

    DOE Patents [OSTI]

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

    1996-06-11

    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.

  9. Background canceling surface alpha detector

    DOE Patents [OSTI]

    MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

    1996-01-01

    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.

  10. Low Background Counting At SNOLAB

    SciTech Connect (OSTI)

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

    2011-04-27

    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.

  11. Microwave meta-atom enhanced spintronic rectification

    SciTech Connect (OSTI)

    Gou, Peng; Xi, Fuchun; Qian, Qinbai; Xu, Jie; Gui, Y. S.; Hu, C.-M.; An, Zhenghua

    2015-04-06

    An artificial meta-atom (MA), or alternatively, a plasmonic antenna, has been demonstrated to significantly enhance the microwave spin rectifying photovoltage by more than two orders in magnitude (∼280) in the ferromagnetic resonance regime. The large enhancement is attributed to the unique structure of the MA which magnifies both microwave electric (∼5) and magnetic (∼56) fields in the same near-field spatial region. Our work develops the interdisciplinary direction with artificial and natural magnetism and may find promising applications in high-frequency or opto-spintronic devices and wireless microwave energy harvesting.

  12. Microwave Excitation In ECRIS plasmas

    SciTech Connect (OSTI)

    Ciavola, G.; Celona, L.; Consoli, F.; Gammino, S.; Maimone, F.; Barbarino, S.; Catalano, R. S.; Mascali, D.; Tumino, L.

    2007-09-28

    A number of phenomena related to the electron cyclotron resonance ion sources (ECRIS) has been better understood recently by means of the improvement of comprehension of the coupling mechanism between microwave generators and ECR plasma. In particular, the two frequency heating and the frequency tuning effect, that permit a remarkable increase of the current for the highest charge states ions, can be explained in terms of modes excitation in the cylindrical cavity of the plasma chamber. Calculations based on this theoretical approach have been performed, and the major results will be presented. It will be shown that the electric field pattern completely changes for a few MHz frequency variations and the changes in ECRIS performances can be correlated to the efficiency of the power transfer between electromagnetic field and plasma.

  13. Planar slot coupled microwave hybrid

    DOE Patents [OSTI]

    Petter, Jeffrey K.

    1991-01-01

    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.

  14. Solar Background Document 3 | Department of Energy

    Office of Environmental Management (EM)

    3 Solar Background Document 3 A list of private sector investment in Solyndra. Solar Background Document 3.pdf (12.43 KB) More Documents & Publications Solar Background Document 2 ...

  15. Microwave Melting | Y-12 National Security Complex

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

    by this browser. Download video Captions: On Time: 2:90 min. Ed Ripley and Kenneth Evans explain some of the benefits of microwave heating technology, including how its uses...

  16. Continuous, real time microwave plasma element sensor

    DOE Patents [OSTI]

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

    1995-12-26

    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.

  17. Chemical vapor infiltration using microwave energy

    DOE Patents [OSTI]

    Devlin, David J.; Currier, Robert P.; Laia, Jr., Joseph R.; Barbero, Robert S.

    1993-01-01

    A method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

  18. Continuous, real time microwave plasma element sensor

    DOE Patents [OSTI]

    Woskov, Paul P.; Smatlak, Donna L.; Cohn, Daniel R.; Wittle, J. Kenneth; Titus, Charles H.; Surma, Jeffrey E.

    1995-01-01

    Microwave-induced plasma 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.

  19. Modulated microwave microscopy and probes used therewith

    DOE Patents [OSTI]

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

    2012-09-11

    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.

  20. Container evaluation for microwave solidification project

    SciTech Connect (OSTI)

    Smith, J.A.

    1994-08-01

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

  1. Widget:Background-Image | Open Energy Information

    Open Energy Info (EERE)

    Edit History Widget:Background-Image Jump to: navigation, search MHK Instrumentation & Sensor Database pages use this widget to load device images as CSS background rather than...

  2. Solar Background Document 5 | Department of Energy

    Office of Environmental Management (EM)

    5 Solar Background Document 5 Graph illustrating Chinese Development Bank financing to Chinese solar companies. Solar Background Document 5.pdf (29.35 KB) More Documents & ...

  3. Solar Background Document 1 | Department of Energy

    Office of Environmental Management (EM)

    1 Solar Background Document 1 A timeline outlining the Energy Department's extensive review of the Solyndra Solar loan guarantee application from 2006 to 2009. Solar Background ...

  4. Solar Background Document 4 | Department of Energy

    Office of Environmental Management (EM)

    4 Solar Background Document 4 Graph illustrating global distribution of solar manufacturing market share from 1990 to 2010. Solar Background Document 4.pdf (57.32 KB) More ...

  5. Solar Background Document 2 | Department of Energy

    Office of Environmental Management (EM)

    Solar Background Document 2 Media reports and other independent analysts which pointed to Solyndra as a very promising, innovative company. Solar Background Document 2.pdf (17.42 ...

  6. Detection of contraband using microwave radiation

    DOE Patents [OSTI]

    Toth, Richard P.; Loubriel, Guillermo M.; Bacon, Larry D.; Watson, Robert D.

    2002-01-01

    The present invention relates to a method and system for using microwave radiation to detect contraband hidden inside of a non-metallic container, such as a pneumatic vehicle tire. The method relies on the attenuation, retardation, time delay, or phase shift of microwave radiation as it passes through the container plus the contraband. The method is non-invasive, non-destructive, low power, and does not require physical contact with the container.

  7. Continuous microwave regeneration apparatus for absorption media

    DOE Patents [OSTI]

    Smith, Douglas D.

    1999-01-01

    A method and apparatus for continuously drying and regenerating ceramic beads for use in process gas moisture drying operations such as glove boxes. A microwave energy source is coupled to a process chamber to internally heat the ceramic beads and vaporize moisture contained therein. In a preferred embodiment, the moisture laden ceramic beads are conveyed toward the microwave source by a screw mechanism. The regenerated beads flow down outside of the screw mechanism and are available to absorb additional moisture.

  8. Gensheng Wang | Argonne National Laboratory

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

    Gensheng Wang Assistant Physicist Summary of Research Gensheng Wang is an Assistant Physicist at High Energy Physics division. His scientific interests are precision measurements of the Cosmic Microwave Background (CMB), Dark Matter (DM) particle searches, and Neutrino-Less Double Beta Decay (NLDBD) searches. He worked on CDMS and SPTpol before. Most recently, he is working on SPT-3G TES bolometric detector array for CMB and low-Tc TES detector for NLDBD. Wang has expertise on cryogenic

  9. Large-Angular-Scale Anisotropy in the Cosmic Background Radiation

    DOE R&D Accomplishments [OSTI]

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

    1980-05-01

    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.

  10. Large-Volume Resonant Microwave Discharge for Plasma Cleaning...

    Office of Scientific and Technical Information (OSTI)

    Large-Volume Resonant Microwave Discharge for Plasma Cleaning of a CEBAF 5-Cell SRF Cavity Citation Details In-Document Search Title: Large-Volume Resonant Microwave Discharge for...

  11. ARM: Microwave Water Radiometer (MWR): water liq. and vapor along...

    Office of Scientific and Technical Information (OSTI)

    Microwave Water Radiometer (MWR): water liq. and vapor along line of sight (LOS) path Title: ARM: Microwave Water Radiometer (MWR): water liq. and vapor along line of sight (LOS) ...

  12. Solar Background Document 6 | Department of Energy

    Energy Savers [EERE]

    Solar Background Document 6 Graph illustrating solar cell production in the United States and China from 2002 to 2010. Solar Background Document 6.pdf (38.97 KB) More Documents & ...

  13. Microwave and Radio Frequency Workshop | Department of Energy

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

    Workshops » Microwave and Radio Frequency Workshop Microwave and Radio Frequency Workshop July 25, 2012 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 (MW) and radio frequency (RF) energy - and their potential to impact advanced manufacturing. Exploiting the material interactions of MW and RF energy is a route to developing energy-saving process

  14. Microwave off-gas treatment apparatus and process

    DOE Patents [OSTI]

    Schulz, Rebecca L.; Clark, David E.; Wicks, George G.

    2003-01-01

    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.

  15. Microwave accelerator E-beam pumped laser

    DOE Patents [OSTI]

    Brau, Charles A.; Stein, William E.; Rockwood, Stephen D.

    1980-01-01

    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.

  16. Apparatus for microwave heat treatment of manufactured components

    SciTech Connect (OSTI)

    Babcock & Wilcox Technical Services Y-12, LLC

    2008-04-15

    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.

  17. Methods for microwave heat treatment of manufactured components

    SciTech Connect (OSTI)

    Ripley, Edward B.

    2010-08-03

    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.

  18. Synthesis of ultrafine powders by microwave heating

    DOE Patents [OSTI]

    Meek, Thomas T.; Sheinberg, Haskell; Blake, Rodger D.

    1988-01-01

    A method of synthesizing ultrafine powders using microwaves is described. A water soluble material is dissolved in water and the resulting aqueous solution is exposed to microwaves until the water has been removed. The resulting material is an ultrafine powder. This method can be used to make Al.sub.2 O.sub.3, NiO+Al.sub.2 O.sub.3 and NiO as well as a number of other materials including GaBa.sub.2 Cu.sub.3 O.sub.x.

  19. Synthesis of ultrafine powders by microwave heating

    DOE Patents [OSTI]

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

    1987-04-24

    A method of synthesizing ultrafine powders using microwaves is described. A water soluble material is dissolved in water and the resulting aqueous solution is exposed to microwaves until the water has dissolved. The resulting material is an ultrafine powder. This method can be used to make Al/sub 2/O/sub 3/, NiO /plus/ Al/sub 2/O/sub 3/ and NiO as well as a number of other materials including GaBa/sub 2/Cu/sub 3/O/sub x/. 1 tab.

  20. Clamshell microwave cavities having a superconductive coating

    DOE Patents [OSTI]

    Cooke, D. Wayne; Arendt, Paul N.; Piel, Helmut

    1994-01-01

    A microwave cavity including a pair of opposing clamshell halves, such halves comprised of a metal selected from the group consisting of silver, copper, or a silver-based alloy, wherein the cavity is further characterized as exhibiting a dominant TE.sub.011 mode is provided together with an embodiment wherein the interior concave surfaces of the clamshell halves are coated with a superconductive material. In the case of copper clamshell halves, the microwave cavity has a Q-value of about 1.2.times.10.sup.5 as measured at a temperature of 10K and a frequency of 10 GHz.

  1. Neutral hydrogen absorption by galaxies and implications for the soft X-ray background

    SciTech Connect (OSTI)

    Corbelli, E.; Schneider, S.E. Massachusetts Univ., Amherst )

    1990-06-01

    Results are presented from a search for neutral hydrogen absorption in the 21-cm spectra of 59 radio continuum sources in the proximity of spiral and lenticular galaxies using the Arecibo radio telescope. Five galaxies showed possible but uncertain absorption. For the 54 other sources, the column density of the neutral hydrogen in the intervening material is well below 2 x 10 to the 19th/cu cm or the spin temperature is at least one order of magnitude above the microwave background temperature. For these cases, subthermal effects are not hiding appreciable amounts of neutral hydrogen. 47 refs.

  2. Optimized ECR plasma apparatus with varied microwave window thickness

    DOE Patents [OSTI]

    Berry, Lee A.

    1995-01-01

    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.

  3. Optimized ECR plasma apparatus with varied microwave window thickness

    DOE Patents [OSTI]

    Berry, L.A.

    1995-11-14

    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.

  4. Piezoelectric-tuned microwave cavity for absorption spectrometry

    DOE Patents [OSTI]

    Leskovar, Branko; Buscher, Harold T.; Kolbe, William F.

    1978-01-01

    Gas samples are analyzed for pollutants in a microwave cavity that is provided with two highly polished walls. One wall of the cavity is mechanically driven with a piezoelectric transducer at a low frequency to tune the cavity over a band of microwave frequencies in synchronism with frequency modulated microwave energy applied to the cavity. Absorption of microwave energy over the tuned frequencies is detected, and energy absorption at a particular microwave frequency is an indication of a particular pollutant in the gas sample.

  5. Planar controlled zone microwave plasma system

    SciTech Connect (OSTI)

    Ripley, Edward B.; Seals, Roland D.; Morrell, Jonathan S.

    2011-10-04

    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.

  6. Environmental assessment: South microwave communication facilities

    SciTech Connect (OSTI)

    Not Available

    1989-06-01

    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.

  7. High frequency background quantization of gravity

    SciTech Connect (OSTI)

    von Borzeszkowski, H.

    1982-06-01

    Considering background quantization of gravitational fields, it is generally assumed that the classical background satisfies Einstein's gravitational equations. However, there exist arguments showing that, for high frequency (quantum) fluctuations, this assumption has to be replaced by a condition describing the back reaction of fluctuations on the background. It is shown that such an approach leads to limitations for the quantum procedure which occur at distances larger than Planck's elementary length 1 = (Gh/c/sup 3/)/sup 1/2/.

  8. Paducah Background Factsheet | Department of Energy

    Energy Savers [EERE]

    of Depleted Uranium and Subsequent Transactions, May 15, 2012 Paducah Background Factsheet0.pdf (100.05 KB) More Documents & Publications Excess Uranium Inventory ...

  9. Background Information for Independent Review Team. Lifecycle...

    Office of Scientific and Technical Information (OSTI)

    Background Information for Independent Review Team. Lifecycle Plan and FY14 Quarterly ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  10. Solar Background Document 7 | Department of Energy

    Office of Environmental Management (EM)

    7 Solar Background Document 7 Chart comparing global solar market in 2009 with the market today, illustrating the changing market conditions that Solyndra faced after receiving a ...