National Library of Energy BETA

Sample records for foreground background beaver

  1. Foreground contributions to the Cosmic Microwave Background

    E-Print Network [OSTI]

    Tadeusz Wibig; Arnold W. Wolfendale

    2005-06-21

    A detailed search has been made for evidence of foreground contributions to the Cosmic Microwave Background (CMB) WMAP, such foregrounds being related to our Galaxy. We find remarkable results. On the largest angular scales we find significant differences between the power in the fluctuations for positive and negative Galactic latitudes and between the four Galactic Quadrants. There are also differences between the power spectrum at latitudes within 10 deg of the Plane and at higher latitudes. The `slope' of the power spectrum has similar variations. In an effort to find the origin of these Galactic-style effects we have examined the evidence from Galactic gamma rays, specifically from the EGRET instrument. A correlation is found between gamma ray intensities and the CMB and other cosmic ray indicators. Most of the large scale Galactic asymmetries (eg north, south difference and Quadrant variations) have analogues in cosmic ray asymmetries and also in some other Galactic properties, such as the column density of gas. Thus, it is possible to hypothesise on direct cosmic ray-induced contributions, although it may be that cosmic rays are simply the indicators of Galactic `conditions' which are influencing the residual CMB fluctuations. Irrespective of the actual cause of the correlations we have endeavoured to extrapolate to the situation where the residual foreground is minimised. The effect on the usually-derived cosmological properties - universal matter content, ionization, the tensor contribution, tilt and curvature - is briefly examined.

  2. ROBUST AND UNBIASED FOREGROUND / BACKGROUND ENERGY FOR MULTI-VIEW STEREO

    E-Print Network [OSTI]

    Wong, Kenneth K.Y.

    maps even in the absence of the photo-consistency energy. To the best of our #12;knowledgeROBUST AND UNBIASED FOREGROUND / BACKGROUND ENERGY FOR MULTI-VIEW STEREO Zhihu Chen and Kwan-Yee K@cs.hku.hk, kykwong@cs.hku.hk Keywords: Multi-View Stereo, Photo-Consistency Energy, Foreground / Background Energy

  3. FocalSpace : enhancing users' focus on foreground through diminishing the background

    E-Print Network [OSTI]

    Yao, Lining

    2012-01-01

    In this document we introduce FocalSpace, a video conferencing system that helps users focus on the foreground by diminishing the background through synthetic blur effects. The system can dynamically recognize the relevant ...

  4. Controlling Beaver Damage 

    E-Print Network [OSTI]

    Texas Wildlife Services

    2007-03-13

    Beavers are important because their dams stabilize creek flow, slow runoff and create ponds. However, these same dams can negatively alter the flow of creeks. Damage prevention, control and various trapping methods are discussed in this publication....

  5. Pennsylvania Nuclear Profile - Beaver Valley

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

    Beaver Valley" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

  6. BFORE: The B-mode Foreground Experiment

    E-Print Network [OSTI]

    Niemack, Michael D; de Bernardis, Francesco; Boulanger, Francois; Bryan, Sean; Devlin, Mark; Dunkley, Joanna; Eales, Steve; Gomez, Haley; Groppi, Chris; Henderson, Shawn; Hillbrand, Seth; Hubmayr, Johannes; Mauskopf, Philip; McMahon, Jeff; Miville-Deschênes, Marc-Antoine; Pascale, Enzo; Pisano, Giampaolo; Novak, Giles; Scott, Douglas; Soler, Juan; Tucker, Carole

    2015-01-01

    The B-mode Foreground Experiment (BFORE) is a proposed NASA balloon project designed to make optimal use of the sub-orbital platform by concentrating on three dust foreground bands (270, 350, and 600 GHz) that complement ground-based cosmic microwave background (CMB) programs. BFORE will survey ~1/4 of the sky with 1.7 - 3.7 arcminute resolution, enabling precise characterization of the Galactic dust that now limits constraints on inflation from CMB B-mode polarization measurements. In addition, BFORE's combination of frequency coverage, large survey area, and angular resolution enables science far beyond the critical goal of measuring foregrounds. BFORE will constrain the velocities of thousands of galaxy clusters, provide a new window on the cosmic infrared background, and probe magnetic fields in the interstellar medium. We review the BFORE science case, timeline, and instrument design, which is based on a compact off-axis telescope coupled to >10,000 superconducting detectors.

  7. Background

    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...

  8. Background

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

    0 Background Highway construction workers, airport maintenance personnel, and film crews use small, portable lighting systems known as "mobile lighting." Traditionally, mobile...

  9. Forest Resources: Beaver Pond Management for Waterfowl http://tfsweb.tamu.edu Page 1 of 1

    E-Print Network [OSTI]

    Forest Resources: Beaver Pond Management for Waterfowl http://tfsweb.tamu.edu Page 1 of 1 Foraging--in and around beaver ponds provide excellent fall and winter forage for ducks, especially mallards, wood ducks and black ducks. Beaver ponds with living mast trees can be managed as a green tree reservoir by installing

  10. Minimum Cuts of A Time-Varying Background David Russell and Shaogang Gong

    E-Print Network [OSTI]

    Gong, Shaogang

    foreground, whilst people park their cars, which are eventually subsumed by the background. The most commonly implementations it is difficult to avoid such background models being contaminated by foreground scene content

  11. SPIDER OPTIMIZATION. II. OPTICAL, MAGNETIC, AND FOREGROUND EFFECTS

    SciTech Connect (OSTI)

    O'Dea, D. T.; Clark, C. N.; Contaldi, C. R. [Theoretical Physics, Blackett Laboratory, Imperial College, London (United Kingdom); Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, Cardiff (United Kingdom); Amiri, M.; Burger, B.; Davis, G. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC (Canada); Benton, S. J. [Department of Physics, University of Toronto, Toronto, ON (Canada); Bock, J. J.; Crill, B. P.; Dore, O.; Filippini, J. P. [Department of Physics, California Institute of Technology, Pasadena, CA (United States); Bond, J. R.; Farhang, M. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON (Canada); Bonetti, J. A. [Jet Propulsion Laboratory, Pasadena, CA (United States); Bryan, S. [Department of Physics, Case Western Reserve University, Cleveland, OH (United States); Chiang, H. C.; Fraisse, A. A. [Department of Physics, Princeton University, Princeton, NJ (United States); Fissel, L. M.; Gandilo, N. N. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON (Canada)

    2011-09-01

    SPIDER is a balloon-borne instrument designed to map the polarization of the cosmic microwave background (CMB) with degree-scale resolution over a large fraction of the sky. SPIDER's main goal is to measure the amplitude of primordial gravitational waves through their imprint on the polarization of the CMB if the tensor-to-scalar ratio, r, is greater than 0.03. To achieve this goal, instrumental systematic errors must be controlled with unprecedented accuracy. Here, we build on previous work to use simulations of SPIDER observations to examine the impact of several systematic effects that have been characterized through testing and modeling of various instrument components. In particular, we investigate the impact of the non-ideal spectral response of the half-wave plates, coupling between focal-plane components and Earth's magnetic field, and beam mismatches and asymmetries. We also present a model of diffuse polarized foreground emission based on a three-dimensional model of the Galactic magnetic field and dust, and study the interaction of this foreground emission with our observation strategy and instrumental effects. We find that the expected level of foreground and systematic contamination is sufficiently low for SPIDER to achieve its science goals.

  12. Habitat Use by Beaver Along the Big Sioux River in Eastern South Dakota

    E-Print Network [OSTI]

    to livestock grazing (Smith and Flake 1983). Grazing can have negative effects on beaver Castor canadensis~ 0.01) than uncuttrees. Mean distance from water of cut trees was less (P ~ 0.01) than for uncut a gradual decline in stands of willow Salix spp. because beaver harvest mature woody plants and cattle

  13. Boralex Beaver Livermore Falls Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass FacilityBluegrassBoralex Beaver Livermore Falls

  14. Foreground Subtraction in Intensity Mapping with the SKA

    E-Print Network [OSTI]

    Wolz, Laura; Alonso, David; Blake, Chris; Bull, Philip; Chang, Tzu-Ching; Ferreira, Pedro G; Kuo, Cheng-Yu; Santos, Marios G; Shaw, Richard

    2015-01-01

    21cm intensity mapping experiments aim to observe the diffuse neutral hydrogen (HI) distribution on large scales which traces the Cosmic structure. The Square Kilometre Array (SKA) will have the capacity to measure the 21cm signal over a large fraction of the sky. However, the redshifted 21cm signal in the respective frequencies is faint compared to the Galactic foregrounds produced by synchrotron and free-free electron emission. In this article, we review selected foreground subtraction methods suggested to effectively separate the 21cm signal from the foregrounds with intensity mapping simulations or data. We simulate an intensity mapping experiment feasible with SKA phase 1 including extragalactic and Galactic foregrounds. We give an example of the residuals of the foreground subtraction with a independent component analysis and show that the angular power spectrum is recovered within the statistical errors on most scales. Additionally, the scale of the Baryon Acoustic Oscillations is shown to be unaffecte...

  15. Plan-view Trajectory Estimation with Dense Stereo Background Models

    E-Print Network [OSTI]

    Darrell, T.

    2001-02-01

    In a known environment, objects may be tracked in multiple views using a set of back-ground models. Stereo-based models can be illumination-invariant, but often have undefined values which inevitably lead to foreground ...

  16. Ecology, management, and conservation implications of North American beaver (Castor canadensis) in dryland streams

    E-Print Network [OSTI]

    Olden, Julian D.

    change and human population growth. 2. Despite growing interest in reintroduction programmes. Freshw. Ecosyst. 24: 391­409 (2014) Published online 13 January 2014 in Wiley Online Library engineers with major influence on landscape form and the structure of aquatic ecosystems. Beaver dams create

  17. Vote Tampering in a District Justice Election in Beaver County, Pa.

    E-Print Network [OSTI]

    Vote Tampering in a District Justice Election in Beaver County, Pa. Ilaria DiMatteo and Joseph B, the ballots (which were paper) were tampered with, to Mrs. Laughlin's benefit. A District Justice is the only of this index indicate precincts where ballot boxes may have been tampered with. Under the hypothesis

  18. Habitat and Conservation Status of the Beaver in the Sierra San Luis Sonora, M6xico

    E-Print Network [OSTI]

    Nacional Autónoma de México, Universidad

    (Castorcanadensis)in northeasternSonora,Mexico, is uncertain. We surveyedthe Cajon Bonito Riverto assess thebeaver the conservation status of the species, including its distribution and abundance (Grigera 2002). . In Mexico, isolated beaver populations have been documented along the U.S.-Mexico border (Leopold 1977, Hoffmeister

  19. TRIBUTE TO STANLEY DODSON Does the morphology of beaver ponds alter downstream

    E-Print Network [OSTI]

    McIntosh, Angus

    ratio of beaver dam height (which determines hydraulic head) to pond surface area and related to pond depended on pond morphology, increasing downstream of small ponds with high dams, but only during the low-limiting nutrients downstream. Both periphyton biomass and BOM decreased down- stream of small ponds with high dams

  20. First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission

    E-Print Network [OSTI]

    C. Bennett; R. S. Hill; G. Hinshaw; M. R. Nolta; N. Odegard; L. Page; D. N. Spergel; J. L. Weiland; E. L. Wright; M. Halpern; N. Jarosik; A. Kogut; M. Limon; S. S. Meyer; G. S. Tucker; E. Wollack

    2003-06-05

    Full sky maps are made in five microwave frequency bands to separate the temperature anisotropy of the CMB from foreground emission. We define masks that excise regions of high foreground emission. The effectiveness of template fits to remove foreground emission from the WMAP data is examined. These efforts result in a CMB map with minimal contamination and a demonstration that the WMAP CMB power spectrum is insensitive to residual foreground emission. We construct a model of the Galactic emission components. We find that the Milky Way resembles other normal spiral galaxies between 408 MHz and 23 GHz, with a synchrotron spectral index that is flattest (beta ~ -2.5) near star-forming regions, especially in the plane, and steepest (beta ~ -3) in the halo. The significant synchrotron index steepening out of the plane suggests a diffusion process in which the halo electrons are trapped in the Galactic potential long enough to suffer synchrotron and inverse Compton energy losses and hence a spectral steepening. The synchrotron index is steeper in the WMAP bands than in lower frequency radio surveys, with a spectral break near 20 GHz to beta < -3. The modeled thermal dust spectral index is also steep in the WMAP bands, with beta ~ 2.2. Microwave and H alpha measurements of the ionized gas agree. Spinning dust emission is limited to < ~5% of the Ka-band foreground emission. A catalog of 208 point sources is presented. Derived source counts suggest a contribution to the anisotropy power from unresolved sources of (15.0 +- 1.4) 10^{-3} microK^2 sr at Q-band and negligible levels at V-band and W-band.

  1. Can residuals of the solar system foreground explain low multipole anomalies of the CMB?

    SciTech Connect (OSTI)

    Hansen, M.; Kim, J.; Frejsel, A.M.; Ramazanov, S.; Naselsky, P.; Zhao, W. [Niels Bohr Institute and DISCOVERY Center, Blegdamsvej 17, 2100 Copenhagen, Ø (Denmark); Burigana, C., E-mail: kirstejn@nbi.dk, E-mail: jkim@nbi.dk, E-mail: annemett@nbi.dk, E-mail: sabir_ra@nbi.dk, E-mail: naselsky@nbi.dk, E-mail: wzhao7@nbi.ku.dk, E-mail: burigana@iasfbo.inaf.it [INAF/IASF, Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via P. Gobetti 101, 40129, Bologna (Italy)

    2012-10-01

    The low multipole anomalies of the Cosmic Microwave Background has received much attention during the last few years. It is still not ascertained whether these anomalies are indeed primordial or the result of systematics or foregrounds. An example of a foreground, which could generate some non-Gaussian and statistically anisotropic features at low multipole range, is the very symmetric Kuiper Belt in the outer solar system. In this paper, expanding upon the methods presented in [1], we investigate the contributions from the Kuiper Belt objects (KBO) to the WMAP ILC 7 map, whereby we can minimize the contrast in power between even and odd multipoles in the CMB, discussed in [2,3]. We submit our KBO de-correlated CMB signal to several tests, to analyze its validity, and find that incorporation of the KBO emission can decrease the quadrupole-octupole alignment and parity asymmetry problems, provided that the KBO signals has a non-cosmological dipole modulation, associated with the statistical anisotropy of the ILC 7 map. Additionally, we show that the amplitude of the dipole modulation, within a 2? interval, is in agreement with the corresponding amplitudes, discussed in [4].

  2. Narrative Foreground in the Plays of Osvaldo Dragún

    E-Print Network [OSTI]

    Gladhart, Amalia

    1993-04-01

    projection, and flashback, all of these plays foreground their narrative structures. Frank Dauster emphasizes the similarities between El amasijo, Historias, and Hijos del terremoto (an earlier version of ¡Arriba Corazón!) when he describes "el rechazo de... 109 Carlson, Marvin. Theories of the Theatre. Ithaca: Cornell U P, 1984. Dauster, Frank. "Los hijos del terremoto: Imágenes de un recuerdo." Latin American Theatre Review 22.1 (1988): 5-11. Dragún, Osvaldo. "El amasijo." Nueve dramaturgos...

  3. Neutral hydrogen structures trace dust polarization angle: Implications for the interstellar medium and CMB foregrounds

    E-Print Network [OSTI]

    Clark, S E; Peek, J E G; Putman, M E; Babler, B L

    2015-01-01

    Using high-resolution data from the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) survey, we show that linear structure in Galactic neutral hydrogen (HI) correlates with the magnetic field orientation implied by Planck 353 GHz polarized dust emission. The structure of the neutral interstellar medium is more tightly coupled to the magnetic field than previously known. At high Galactic latitudes, where the Planck data are noise-dominated, the HI data provide an independent constraint on the Galactic magnetic field orientation, and hence the local dust polarization angle. We detect strong cross-correlations between template maps constructed from estimates of dust intensity combined with either HI-derived angles, starlight polarization angles, or Planck 353 GHz angles. The HI data thus provide a new tool in the search for inflationary gravitational wave B-mode polarization in the cosmic microwave background, which is currently limited by dust foreground contamination.

  4. Post-Fire Debris-Flow Hazard Assessment of the Area Burned by the 2013 Beaver Creek Fire near Hailey, Central Idaho

    E-Print Network [OSTI]

    Torgersen, Christian

    Post-Fire Debris-Flow Hazard Assessment of the Area Burned by the 2013 Beaver Creek Fire near-flow hazard assessment of the area burned by the 2013 Beaver Creek Fire near Hailey, central Idaho: U­1273 Prepared in cooperation with Blaine County, Idaho #12;#12;Post-Fire Debris-Flow Hazard Assessment

  5. Foreground contamination of the WMAP CMB maps from the perspective of the matched circle test

    E-Print Network [OSTI]

    H. Then

    2006-10-16

    WMAP has provided CMB maps of the full sky. The raw data is subject to foreground contamination, in particular near to the Galactic plane. Foreground cleaned maps have been derived, e.g., the internal linear combination (ILC) map of Bennett et al. and the reduced foreground TOH map of Tegmark et al. Using S statistics we examine whether residual foreground contamination is left over in the foreground cleaned maps. In particular, we specify which parts of the foreground cleaned maps are sufficiently accurate for the circle-in-the-sky signature. We generalise the S statistic, called D statistic, such that the circle test can deal with CMB maps in which the contaminated regions of the sky are excluded with masks.

  6. Beaver County, Pennsylvania ASHRAE 169-2006 Climate Zone | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAEInformation Beaver

  7. Intra-amygdala infusion of the protein kinase Mzeta inhibitor ZIP disrupts foreground context fear memory

    E-Print Network [OSTI]

    Helmstetter, Fred J.

    Intra-amygdala infusion of the protein kinase Mzeta inhibitor ZIP disrupts foreground context fear-pseudosubstrate inhibitory peptide (ZIP) remains in the brain after infusion. Here, we demon- strate that foreground context the brain by 24 h after infusion. These data contribute to a growing body of lit- erature that demonstrates

  8. A Hybrid Color-Based Foreground Object Detection Method for Automated Marine

    E-Print Network [OSTI]

    Kalva, Hari

    A Hybrid Color-Based Foreground Object Detection Method for Automated Marine Surveillance Daniel for the marine surveillance applications. Our approach combines an existing foreground object detection method variation of edges. We also establish the set of requirements any practical marine surveillance algorithm

  9. On the Beavers-Joseph-Saffman boundary condition for curved interfaces

    E-Print Network [OSTI]

    Sören Dobberschütz

    2015-04-22

    The appropriate boundary condition between an unconfined incompressible viscous fluid and a porous medium is given by the law of Beavers and Joseph. The latter has been justified both experimentally and mathematically, using the method of periodic homogenisation. However, all results so far deal only with the case of a planar boundary. In this work, we consider the case of a curved, macroscopically periodic boundary. By using a coordinate transformation, we obtain a description of the flow in a domain with a planar boundary, for which we derive the effective behaviour: The effective velocity is continuous in normal direction. Tangential to the interface, a slip occurs. Additionally, a pressure jump occurs. The magnitude of the slip velocity as well as the jump in pressure can be determined with the help of a generalised boundary layer function. The results indicate the validity of a generalised law of Beavers and Joseph, where the geometry of the interface has an influence on the slip and jump constants.

  10. Vibration Background

    E-Print Network [OSTI]

    Dickinson, Kristin

    2012-01-01

    Vibration Background By Selim Özdo?an Translated by Kristinteacher says we have a vibration background, what is that? Igave some thought to our vibration background. It’s a good

  11. The clustering of merging star-forming haloes: dust emission as high frequency arcminute CMB foreground

    E-Print Network [OSTI]

    Righi, M; Sunyaev, R

    2007-01-01

    Future observations of CMB anisotropies will be able to probe high multipole regions of the angular power spectrum, corresponding to a resolution of a few arcminutes. Dust emission from merging haloes is one of the foregrounds that will affect such very small scales. We estimate the contribution to CMB angular fluctuations from objects which are bright in the sub-millimeter band due to intense star formation bursts following merging episodes. We also consider the effect of the intergalactic dust expelled from galaxies by strong winds and AGN activity. We base our approach on the Lacey-Cole merger model and on the Kennicutt relation which connects the star formation rate in galaxies with their infrared luminosity. We set the free parameters of the model in order to not exceed the SCUBA source counts, the Madau plot of star formation rate in the universe and COBE/FIRAS data on the intensity of the sub-millimeter cosmic background radiation. We show that the angular power spectrum arising from the distribution o...

  12. Bipole-dipole survey at Roosevelt Hot Springs, Thermal Area, Beaver County, Utah

    SciTech Connect (OSTI)

    Frangos, W.; Ward, S.H.

    1980-09-01

    A bipole-dipole electrical resistivity survey at Roosevelt Hot Springs thermal area, Beaver County, Utah was undertaken to evaluate the technique in a well-studied Basin and Range geothermal prospect. The major electrical characteristics of the area are clearly revealed but are not particularly descriptive of the geothermal system. More subtle variations of electrical resistivity accompanying the geothermal activity are detectable, although the influence of near-surface lateral resistivity variations imposes upon the survey design the necessity of a high station density. A useful practical step is to conduct a survey using transmitter locations and orientations which minimize the response of known features such as the resistivity boundary due to a range front fault. Survey results illustrate the effects of transmitter orientation and placement, and of subtle lateral resistivity variations. A known near-surface conductive zone is detected while no evidence is found for a deep conductive region.

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

    SciTech Connect (OSTI)

    Liu, Hao [Niels Bohr Institute and Discovery Center, Copenhagen University, Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark); Mertsch, Philipp [Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, M/S 29, Menlo Park, CA 94025 (United States); Sarkar, Subir, E-mail: liuhao@nbi.dk [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

    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.

  14. Measuring the tensor to scalar ratio from CMB B-modes in presence of foregrounds

    E-Print Network [OSTI]

    Betoule, Marc; Delabrouille, J; Jeune, M Le; Cardoso, Jean-François

    2009-01-01

    Abreg: We investigate the impact of polarized foreground emission on the performances of future CMB experiments in measuring the tensor-to-scalar ratio r. We design a component separation pipeline, based on the Smica method, aimed at estimating r and the foreground contamination from the data with no prior assumption on the frequency dependence or spatial distribution of the foregrounds. We derive error bars accounting for the uncertainty on foreground contribution. We use the current knowledge of galactic and extra-galactic foregrounds as implemented in the Planck Sky Model (PSM), to build simulations of the sky emission for various experimental setups. Our method, permits us to detect r = 0.1 at more than 3 sigma from B-modes only with Planck data, and r = 0.001 at 6 sigma for the most ambitious designs of the future EPIC probe. We find that all-sky experiments permit a proper measurement of the reionization bump despite the large scale foreground emission and are nearly insensitive to contamination from po...

  15. IMAGING THE EPOCH OF REIONIZATION: LIMITATIONS FROM FOREGROUND CONFUSION AND IMAGING ALGORITHMS

    SciTech Connect (OSTI)

    Vedantham, Harish; Udaya Shankar, N.; Subrahmanyan, Ravi

    2012-02-01

    Tomography of redshifted 21 cm transition from neutral hydrogen using Fourier synthesis telescopes is a promising tool to study the Epoch of Reionization (EoR). Limiting the confusion from Galactic and extragalactic foregrounds is critical to the success of these telescopes. The instrumental response or the point-spread function (PSF) of such telescopes is inherently three dimensional with frequency mapping to the line-of-sight (LOS) distance. EoR signals will necessarily have to be detected in data where continuum confusion persists; therefore, it is important that the PSF has acceptable frequency structure so that the residual foreground does not confuse the EoR signature. This paper aims to understand the three-dimensional PSF and foreground contamination in the same framework. We develop a formalism to estimate the foreground contamination along frequency, or equivalently LOS dimension, and establish a relationship between foreground contamination in the image plane and visibility weights on the Fourier plane. We identify two dominant sources of LOS foreground contamination-'PSF contamination' and 'gridding contamination'. We show that PSF contamination is localized in LOS wavenumber space, beyond which there potentially exists an 'EoR window' with negligible foreground contamination where we may focus our efforts to detect EoR. PSF contamination in this window may be substantially reduced by judicious choice of a frequency window function. Gridding and imaging algorithms create additional gridding contamination and we propose a new imaging algorithm using the Chirp Z Transform that significantly reduces this contamination. Finally, we demonstrate the analytical relationships and the merit of the new imaging algorithm for the case of imaging with the Murchison Widefield Array.

  16. Foreground contamination in Ly? intensity mapping during the epoch of reionization

    SciTech Connect (OSTI)

    Gong, Yan; Cooray, Asantha; Silva, Marta; Santos, Mario G.

    2014-04-10

    The intensity mapping of Ly? emission during the epoch of reionization will be contaminated by foreground emission lines from lower redshifts. We calculate the mean intensity and the power spectrum of Ly? emission at z ? 7 and estimate the uncertainties according to the relevant astrophysical processes. We find that the low-redshift emission lines from 6563 Å H?, 5007 Å [O III], and 3727 Å [O II] will be strong contaminants on the observed Ly? power spectrum. We make use of both the star formation rate and luminosity functions to estimate the mean intensity and power spectra of the three foreground lines at z ? 0.5 for H?, z ? 0.9 for [O III], and z ? 1.6 for [O II], as they will contaminate the Ly? emission at z ? 7. The [O II] line is found to be the strongest. We analyze the masking of the bright survey pixels with a foreground line above some line intensity threshold as a way to reduce the contamination in an intensity mapping survey. We find that the foreground contamination can be neglected if we remove pixels with fluxes above 1.4 × 10{sup –20} W m{sup –2}.

  17. Residual foreground contamination in the WMAP data and bias in non-Gaussianity estimation

    SciTech Connect (OSTI)

    Chingangbam, Pravabati; Park, Changbom E-mail: cbp@kias.re.kr

    2013-02-01

    We analyze whether there is any residual foreground contamination in the cleaned WMAP 7 years data for the differential assemblies, Q, V and W. We calculate the correlation between the foreground map, from which long wavelength correlations have been subtracted, and the foreground reduced map for each differential assembly after applying the Galaxy and point sources masks. We find positive correlations for all the differential assemblies, with high statistical significance. For Q and V, we find that a large fraction of the contamination comes from pixels where the foreground maps have positive values larger than three times the rms values. These findings imply the presence of residual contamination from Galactic emissions and unresolved point sources. We redo the analysis after masking the extended point sources cataloque of Scodeller et al. [7] and find a drop in the correlation and corresponding significance values. To quantify the effect of the residual contamination on the search for primordial non-Gaussianity in the CMB we add estimated contaminant fraction to simulated Gaussian CMB maps and calculate the characteristic non-Gaussian deviation shapes of Minkowski Functionals that arise due to the contamination. We find remarkable agreement of these deviation shapes with those measured from WMAP data, which imply that a major fraction of the observed non-Gaussian deviation comes from residual foreground contamination. We also compute non-Gaussian deviations of Minkowski Functionals after applying the point sources mask of Scodeller et al. and find a decrease in the overall amplitudes of the deviations which is consistent with a decrease in the level of contamination.

  18. Background & Publications

    E-Print Network [OSTI]

    Home Background & Projects Calendar Publications Staff Directory Station Videos Links Search to pit. Harvest is expected to continue through this week. Balaton fruit set is light, and harvest abandon some sweet cherry blocks. Brown MAES Home | Field Stations | Station Home | Publications | Fruit

  19. Background & Publications

    E-Print Network [OSTI]

    Home Background & Projects Calendar Publications Staff Directory Station Videos Links Search Home | Field Stations | Station Home | Publications | FruitNet Weekly Report GROWING DEGREE DAY is still relatively light, probably due to few wetting periods during early shoot growth. Sun scald

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

    SciTech Connect (OSTI)

    Osborne, Stephen J.; Hanson, Duncan; Doré, 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.

  1. Foreground and Source of a Cluster of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar; Andreas A. Berlind; David W. Hogg

    2005-07-28

    We investigate the origin of a nearly pointlike cluster of 5 ultrahigh energy cosmic rays at RA ~169.2deg and dec ~56.8deg, using Sloan Digital Sky Survey and other data. No particular source candidates are found near the estimated source direction, but the direction is exceptional in having a likely merging pair of galaxy clusters at 140/h Mpc, with an unusually low foreground density. Large scale shocks or another product of the merging galaxy clusters may accelerate the UHECRs, or the merging galaxy clusters may be coincidental and the UHECRs may be accelerated in a rare event of an unexceptional progenitor. Low magnetic deflections in the foreground void may explain why this is the only identified pointlike cluster of so many UHECRs.

  2. A Flat Universe from High-Resolution Maps of the Cosmic Microwave Background Radiation

    E-Print Network [OSTI]

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

    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 2.73K 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 $\\ell_{peak}=(197 \\pm 6)$, with an amplitude $DT_{200}=(69 \\pm 8)\\mu K$. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favoured by standard inflationary scenarios.

  3. Beaver folio, Pennsylvania 

    E-Print Network [OSTI]

    Woolsey, Lester Hood, 1877-1961.

    1905-01-01

    ???2??? & (?? &? ????(????&??? &???(???????(? ? ? ? ? ? ????????? ? ???? ??????? ??? ??? ?? ???????? ????? ????? ?? ????????????? ?? ???? ??? ? ????????? ?? ?? ? ? ???????????????????????? ? ??????????? ???????????? ???? ?? ??????????? ?? ?! ???"#????$????? ? ???% ??? &???&??&&????? ????????'??????????? ????????(???? ??? ??) ????*?+?,????+?-? ? ?%%? $???? 2? )? ??? ??) ???????3?? ??? 4?+5?# ? ?? ? ) ????????#??????3? - &????????????$? ? + ????? ?65??????? ? ?4??&?? ?? 7??%? ? ?? ?? ????% ??????3? ??? &?????4 8?4?? ? # ?./0/? ? # 1 ?????1...???2??? & (?? &? ????(????&??? &???(???????(? ? ??? ???? ???? ?? &??(?)? ? ??????????? ??? ?&?? ?? ?&???+ ? ??????? ??? ? ??(??% ?? &???? &??? ??5? 9# ?./0/:? ? (? $???? ???&???? ? 3??5?53?? ?( & ??????$????? 3?,??? ;?? #5?53? ?! ???"#????$????? ????????????????????????????????????????????????? )? ??? ????$?? ? ?) ???????2???5???? 4?+5...

  4. The Cosmic Background Radiation

    E-Print Network [OSTI]

    George Smoot; Douglas Scott

    1997-11-08

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

  5. PANDEMIC INFLUENZA background briefing

    E-Print Network [OSTI]

    Rambaut, Andrew

    , Dave Carr, David Lynn and Phil Green Transmission electron micrograph of Influenza A virus (WellcomePANDEMIC INFLUENZA background briefing Biomedicine Forum 5 November 2008 compiled by David Evans

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

    E-Print Network [OSTI]

    Martin White; J. D. Cohn

    2002-03-07

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

  7. The Herschel cold debris disks: Confusion with the extragalactic background at 160 ?m

    SciTech Connect (OSTI)

    Gáspár, András; Rieke, George H. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)

    2014-03-20

    The Herschel 'DUst around NEarby Stars' (DUNES) survey has found a number of debris disk candidates that are apparently very cold, with temperatures near 22 K. It has proven difficult to fit their spectral energy distributions with conventional models for debris disks. Given this issue, we carefully examine the alternative explanation that the detections arise from confusion with infrared cirrus and/or background galaxies that are not physically associated with the foreground stars. We find that such an explanation is consistent with all of these detections.

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

    E-Print Network [OSTI]

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

    2007-03-07

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

  9. The Cosmic Background Imager

    E-Print Network [OSTI]

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

    2001-10-05

    Design and performance details are given for the Cosmic Background Imager (CBI), an interferometer array that is measuring the power spectrum of fluctuations in the cosmic microwave background radiation (CMBR) for multipoles in the range 400 switching scheme is used to reject cross-talk and low-frequency pick-up in the signal processing system. The CBI has a 3-axis mount which allows the tracking platform to be rotated about the optical axis, providing improved (u,v) coverage and a powerful discriminant against false signals generated in the receiving electronics. Rotating the tracking platform also permits polarization measurements when some of the antennas are configured for the orthogonal polarization.

  10. Background & Projects Publications

    E-Print Network [OSTI]

    Home Background & Projects Calendar Publications Staff Directory Links Search MAES Home | Field Stations | Station Home | Publications | FruitNet Weekly Report Northern Michigan FruitNet 2006 Weekly vineyards. Side hedging and/or topping shoots will be needed to get light and air to the fruiting zone

  11. Local microwave background radiation

    E-Print Network [OSTI]

    Domingos Soares

    2014-11-13

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

  12. Quantum backgrounds and QFT

    E-Print Network [OSTI]

    Jae-Suk Park; John Terilla; Thomas Tradler

    2009-09-21

    We introduce the concept of a quantum background and a functor QFT. In the case that the QFT moduli space is smooth formal, we construct a flat quantum superconnection on a bundle over QFT which defines algebraic structures relevant to correlation functions in quantum field theory. We go further and identify chain level generalizations of correlation functions which should be present in all quantum field theories.

  13. ARM - Methane Background Information

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach HomepolarizationMeasurementsWarmingMethane Background

  14. LTS Background - Hanford Site

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse Bergkamp Graduate student Subtask22Background About Us LTS Home Page LTS

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

    E-Print Network [OSTI]

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

    2007-01-01

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

  16. MAR Background Report MAR Background Report: Indigenous Protest in Brazil

    E-Print Network [OSTI]

    Milchberg, Howard

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

  17. A tale of tails. Dark matter interpretations of the Fermi GeV excess in light of background model systematics

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

    Calore, Francesca; Cholis, Ilias; McCabe, Christopher; Weniger, Christoph

    2015-03-10

    Several groups have identified an extended excess of gamma rays over the modeled foreground and background emissions towards the Galactic center (GC) based on observations with the Fermi Large Area Telescope. This excess emission is compatible in morphology and spectrum with a telltale sign from dark matter (DM) annihilation. Here, we present a critical reassessment of DM interpretations of the GC signal in light of the foreground and background uncertainties that some of us recently outlaid in Calore et al. (2014). We find that a much larger number of DM models fits the gamma-ray data than previously noted. In particular:more »(1) In the case of DM annihilation into b¯b, we find that even large DM masses up to m??74 GeV are allowed at p-value >0.05. (2) Surprisingly, annihilation into nonrelativistic hh gives a good fit to the data. (3) The inverse Compton emission from ?+?– with m? ~ 60–70 GeV can also account for the excess at higher latitudes, |b|>2°, both in its spectrum and morphology. We also present novel constraints on a large number of mixed annihilation channels, including cascade annihilation involving hidden sector mediators. In conclusion, we show that the current limits from dwarf spheroidal observations are not in tension with a DM interpretation when uncertainties on the DM halo profile are accounted for.« less

  18. Systematic effects in polarizing Fourier transform spectrometers for cosmic microwave background observations

    E-Print Network [OSTI]

    Nagler, Peter C; Kogut, Alan; Tucker, Gregory S

    2015-01-01

    The detection of the primordial B-mode polarization signal of the cosmic microwave background (CMB) would provide evidence for inflation. Yet as has become increasingly clear, the detection of a such a faint signal requires an instrument with both wide frequency coverage to reject foregrounds and excellent control over instrumental systematic effects. Using a polarizing Fourier transform spectrometer (FTS) for CMB observations meets both these requirements. In this work, we present an analysis of instrumental systematic effects in polarizing Fourier transform spectrometers, using the Primordial Inflation Explorer (PIXIE) as a worked example. We analytically solve for the most important systematic effects inherent to the FTS - emissive optical components, misaligned optical components, sampling and phase errors, and spin synchronous effects - and demonstrate that residual systematic error terms after corrections will all be at the sub-nK level, well below the predicted 100 nK B-mode signal.

  19. Background reduction in cryogenic detectors

    SciTech Connect (OSTI)

    Bauer, Daniel A.; /Fermilab

    2005-04-01

    This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.

  20. Background

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

    172,000 sq. ft. of space with its two current divisions, EMCORE Fiber Optics and EMCORE Solar Photovoltaics. In October 2006, EMCORE moved its corporate headquarters to...

  1. Background

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

    from selling an equivalent amount of surplus power. ..... 4 e. Calculation of the net financial value of tangible economic benefits of selling power to Alcoa which would not...

  2. Background

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

    not need to have "perfect information before it takes any action." N. Carolina v. Fed. Energy Regulatory Comm'n, 112 F.3d 1175, 1190 (D.C. Cir. 1997) (quoting Dep't of the Interior...

  3. Background:

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

    iSUPPLIER PORTAL ACCESS SYSTEM REQUIREMENTS Oracle PO Team mlbritt Page 1 10282010 TABLE OF CONTENTS Recommended Browsers for iSupplier Portal Recommended Microsoft Internet...

  4. Background

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

    loads, the Old Corrugated Container (OCC) load (3.275 aMW) and the Unbleached Kraft Pulp and Paper (main mill) load (approximately 17 aMW). PTPC's Contract Demand, defined in...

  5. Background

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

    to ADMINISTRATOR'S DRAFT EQUIVALENT BENEFITS ANALYSIS DETERMINATION FOR CONTRACT OFFER TO THE PORT TOWNSEND PAPER CORPORATION February 3, 2011 This page intentionally left...

  6. BACKGROUND

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O DBiomass andAtomsVehicles and Fuelsj B JBACKGROUND The safe

  7. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJR DTih

  8. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJR DTihTech

  9. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJR DTihTech0

  10. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJR DTihTech0

  11. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJR

  12. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJRAttachments

  13. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014 SignJRAttachments

  14. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014

  15. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014RECORD OF DECISION

  16. Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura BeaneCardwell, ScottGreat:10,-2014RECORD OF DECISION

  17. Background

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1. .&. 'explains the potential health

  18. Background:

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits & Inspections Audits GenerationNovember-5,-2015 SigniSUPPLIER

  19. Background

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby a contractor ofvarDOE PAGES11NationalEnergy Star

  20. Background Investigation Responsible Administrative Unit

    E-Print Network [OSTI]

    safety of the campus community or unacceptable risks to the integrity of financial processes, assets on the Protection of Minors. Specifically, background investigations will be conducted on persons to whom it offers

  1. 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 3? 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

  2. The COMPTEL instrumental line background

    E-Print Network [OSTI]

    G. Weidenspointner; M. Varendorff; U. Oberlack; D. Morris; S. Plueschke; R. Diehl; S. C. Kappadath; M. McConnell; J. Ryan; V. Schoenfelder; H. Steinle

    2000-12-14

    The instrumental line background of the Compton telescope COMPTEL onboard the Compton Gamma-Ray Observatory is due to the activation and/or decay of many isotopes. The major components of this background can be attributed to eight individual isotopes, namely 2D, 22Na, 24Na, 28Al, 40K, 52Mn, 57Ni, and 208Tl. The identification of instrumental lines with specific isotopes is based on the line energies as well as on the variation of the event rate with time, cosmic-ray intensity, and deposited radiation dose during passages through the South-Atlantic Anomaly. The characteristic variation of the event rate due to a specific isotope depends on its life-time, orbital parameters such as the altitude of the satellite above Earth, and the solar cycle. A detailed understanding of the background contributions from instrumental lines is crucial at MeV energies for measuring the cosmic diffuse gamma-ray background and for observing gamma-ray line emission in the interstellar medium or from supernovae and their remnants. Procedures to determine the event rate from each background isotope are described, and their average activity in spacecraft materials over the first seven years of the mission is estimated.

  3. Low Background Micromegas in CAST

    E-Print Network [OSTI]

    J. G. Garza; S. Aune; D. Calvet; J. F. Castel; F. E. Christensen; T. Dafni; M. Davenport; T. Decker; E. Ferrer-Ribas; J. Galán; J. A. García; I. Giomataris; R. M. Hill; F. J. Iguaz; I. G. Irastorza; A. C. Jakobsen; D. Jourde; H. Mirallas; I. Ortega; T. Papaevangelou; M. J. Pivovaroff; J. Ruz; A. Tomás; T. Vafeiadis; J. K. Vogel

    2015-03-17

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as the strategies to further reduce the background level. Finally, we will describe the R&D paths to achieve sub-keV energy thresholds, which could broaden the physics case of axion helioscopes.

  4. 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.

  5. Observations of the Isotropic Diffuse Gamma-ray Background with the EGRET Telescope

    E-Print Network [OSTI]

    T. D. Willis

    2002-01-30

    An Isotropic Diffuse Gamma-Ray Background (IDGRB) in the spectral range 30-10,000 MeV was first reported in the early 1970's using measurements made by the SAS-2 instrument. Data recorded by the Energetic Gamma Ray Experiment Telescope (EGRET) on board the Compton Gamma Ray Observatory (CGRO) over the last 4 years are analysed in order to extract the best measurement yet made of the IDGRB. Extensive analysis of the EGRET instrumental background is presented in order to demonstrate that an uncontaminated data set can be extracted from the EGRET data. A model of the high latitude galactic diffuse foreground emission is presented and the existence of an IDGRB is confirmed. Spatial and spectral analysis of this background is presented. In addition, point source analysis at high galactic latitudes is performed to reveal the existence of a population of extragalactic sources. The characteristics of this population are examined and models of its flux distribution are reported. The question of whether the IDGRB is composed of unresolved point sources is addressed using fluctuation analysis. Finally, possible future directions for gamma ray astronomy are examined through simulations of a future gamma ray telescope: the Gamma-ray Large Area Space Telescope (GLAST). The GLAST baseline design is described and its scientific performance is evaluated. The ability of this telescope to detect 1,000-10,000 new extragalactic sources is demonstrated and the likely impact on the study of the IDGRB is considered.

  6. Low Background Micromegas in CAST

    E-Print Network [OSTI]

    Garza, J G; Calvet, D; Castel, J F; Christensen, F E; Dafni, T; Davenport, M; Decker, T; Ferrer-Ribas, E; Galán, J; García, J A; Giomataris, I; Hill, R M; Iguaz, F J; Irastorza, I G; Jakobsen, A C; Jourde, D; Mirallas, H; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Ruz, J; Tomás, A; Vafeiadis, T; Vogel, J K

    2015-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

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

    E-Print Network [OSTI]

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

    2002-05-23

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

  8. Portsmouth Background | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof EnergyAprilEnergyPartnership forHydrogenandGuidanceBackground

  9. BEDES Background | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuels DataEnergy Webinar:I Due DateOpportunityManual Audit»Background BEDES

  10. A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum

    SciTech Connect (OSTI)

    Moskalenko, Igor V.; Porter, Troy A.; Digel, Seth W.; Michelson, Peter F.; Ormes, Jonathan F.

    2007-12-17

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center.

  11. 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.

  12. Low background aspects of GERDA

    SciTech Connect (OSTI)

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

    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.

  13. DarkLight radiation backgrounds

    SciTech Connect (OSTI)

    Kalantarians, Narbe [University of Texas

    2013-11-01

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

  14. DarkLight radiation backgrounds

    SciTech Connect (OSTI)

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

    2013-11-07

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

  15. Gravitational clustering in Static and Expanding Backgrounds

    E-Print Network [OSTI]

    T. Padmanabhan

    2003-08-28

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

  16. SPECTRUM OF THE MICROWAVE BACKGROUND RADIATION

    E-Print Network [OSTI]

    Richards, P.L.

    2010-01-01

    analysis of the data on the microwave background radiationmillimeter spec­ trum of the microwave background. Ap. J.i 0.06 Technique Averaged Microwave Reference Woo. 'y and

  17. INVESTIGATION Genomic Background and Generation Time

    E-Print Network [OSTI]

    Lynch, Michael

    INVESTIGATION Genomic Background and Generation Time Influence Deleterious Mutation Rates variation is generated and how selection shapes mutation rates over evolutionary time requires knowledge, genomic background and generation time, on deleterious mutation in Daphnia pulicaria, a cyclically

  18. Study of Cosmogenic Neutron Backgrounds at LNGS

    E-Print Network [OSTI]

    Empl, A; Hungerford, E; Mosteiro, P

    2012-01-01

    Cosmic muon interactions are important contributors to backgrounds in underground detectors when searching for rare events. Typically neutrons dominate this background as they are particularly difficult to shield and detect in a veto system. Since actual background data is sparse and not well documented, simulation studies must be used to design shields and predict background rates. This means that validation of any simulation code is necessary to assure reliable results. This work studies the validation of the FLUKA simulation code, and reports the results of a simulation of cosmogenic background for a liquid argon two-phase detector embedded within a water tank and liquid scintillator shielding.

  19. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    SciTech Connect (OSTI)

    Not Available

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site.

  20. 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/.

  1. IDENTIFICATION OF BACKGROUND INTELLECTUAL PROPERTY (BIP)

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

    or is published copyrighted computer software; including minor modifications of such computer software. Background Patent means a patent covering an invention or discovery...

  2. Final Conservation Billing Credit Policy Supplement Background...

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

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

  3. Radiometer System to Map the Cosmic Background Radiation

    E-Print Network [OSTI]

    Gorenstein, Marc V.; Muller, Richard A.; Smoot, George F.; Tyson, J. Anthony

    1977-01-01

    SYSTEM TO MAP THE COSMIC BACKGROUND RADIATION RECEIVEDSystem to Map the Cosmic Background Radiation* Marc V.

  4. MARSAME Appendix B B. SOURCES OF BACKGROUND RADIOACTIVITY

    E-Print Network [OSTI]

    : · The Nuclear Regulatory Commission (NRC) provides information concerning background radioactivity in Background

  5. Chiral perturbation theory in a nuclear background

    E-Print Network [OSTI]

    Weise, Wolfram

    Chiral perturbation theory in a nuclear background L. Girlanda,a,* A. Rusetsky,a,b,1 and W. Weisea March 2004 Abstract We propose a novel way to formulate chiral perturbation theory (ChPT) in a nuclear in the background of the heavy nucleus at Oðp5 � in the chiral expansion, and to derive the leading terms

  6. M2-Branes and Background Fields

    E-Print Network [OSTI]

    Neil Lambert; Paul Richmond

    2009-08-20

    We discuss the coupling of multiple M2-branes to the background 3-form and 6-form gauge fields of eleven-dimensional supergravity, including the coupling of the Fermions. In particular we show in detail how a natural generalization of the Myers flux-terms, along with the resulting curvature of the background metric, leads to mass terms in the effective field theory.

  7. Cosmological String Backgrounds from Gauged WZW Models

    E-Print Network [OSTI]

    C. Kounnas; D. Luest

    1992-05-18

    We discuss the four-dimensional target-space interpretation of bosonic strings based on gauged WZW models, in particular of those based on the non-compact coset space $SL(2,{\\bf R})\\times SO(1,1)^2 /SO(1,1)$. We show that these theories lead, apart from the recently broadly discussed black-hole type of backgrounds, to cosmological string backgrounds, such as an expanding Universe. Which of the two cases is realized depends on the sign of the level of the corresponding Kac-Moody algebra. We discuss various aspects of these new cosmological string backgrounds.

  8. Low background counting techniques at SNOLAB

    SciTech Connect (OSTI)

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

    2013-08-08

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

  9. Lighting Choices - White Background | Department of Energy

    Energy Savers [EERE]

    Choices - White Background Image icon All of these lightbulbs-CFLs, LEDs, and energy-saving incandescents-meet the new energy standards that take effect from 2012-2014. More...

  10. COSMIC MICROWAVE BACKGROUND -- PRESENT STATUS AND FUTURE PROSPECTS

    E-Print Network [OSTI]

    Muller, Richard A.

    2011-01-01

    December 14-20, 1978 COSMIC MICROWAVE BACKGROUND — PRESENTis OTUMHPSB LBL-8799 COSMIC MICROWAVE BACKGROUND ~ PRESENT> lirtLU COSMIC MICROWAVE BACKGROUND — PRESENT STATUS AND

  11. Please Print Student: Beaver Benny 999999999

    E-Print Network [OSTI]

    Escher, Christine

    of study catalog is determined by the term in which that particular field of study was officially declaredMajor 1: 447 201101 Title Code Catalog Term Option 1: 228 201101 Title Code Catalog Term Option 2: Title Code Catalog Term Option 3: Title Code Catalog Term Minor 1: 574 201102 Title Code Catalog Term Minor 2

  12. Beaver MCCs and Switchgear

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura| National2.11 Print3.30.2Lab NewsVulture

  13. The Background Field Approximation in (quantum) cosmology

    E-Print Network [OSTI]

    R. Parentani

    1998-03-12

    We analyze the Hamilton-Jacobi action of gravity and matter in the limit where gravity is treated at the background field approximation. The motivation is to clarify when and how the solutions of the Wheeler-DeWitt equation lead to the Schr\\"odinger equation in a given background. To this end, we determine when and how the total action, solution of the constraint equations of General Relativity, leads to the HJ action for matter in a given background. This is achieved by comparing two neighboring solutions differing slightly in their matter energy content. To first order in the change of the 3-geometries, the change of the gravitational action equals the integral of the matter energy evaluated in the background geometry. Higher order terms are governed by the ``susceptibility'' of the geometry. These classical properties also apply to quantum cosmology since the conditions which legitimize the use of WKB gravitational waves are concomitant with those governing the validity of the background field approximation.

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

    SciTech Connect (OSTI)

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

    2011-11-10

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

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

    Energy Savers [EERE]

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

  16. Background model for the Majorana Demonstrator

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

    Cuesta, C.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Oak Ridge National Lab.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; et al

    2015-01-01

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example usingmore »powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.« less

  17. Tidal Forces in Naked Singularity Backgrounds

    E-Print Network [OSTI]

    Goel, Akash; Roy, Pratim; Sarkar, Tapobrata

    2015-01-01

    The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is generically exemplified by the Roche limit, which predicts the distance within which a celestial object disintegrates due to the tidal effects of a second more massive object. In this paper, using Fermi normal coordinates, we numerically compute the Roche limit for a class of non-rotating naked singularity backgrounds, and compare them with known results for Schwarzschild black holes. Our analysis indicates that there might be substantially large deviations in the magnitudes of tidal forces in naked singularity backgrounds, compared to the black hole cases. If observationally established, these can prove to be an effective indicator of the nature of the singularity at a galactic centre.

  18. Background model for the Majorana Demonstrator

    SciTech Connect (OSTI)

    Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, F. T. [Univ. of South Carolina, Columbia, SC (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barabash, A. S. [Inst. of Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Ejiri, H. [Osaka Univ. (Japan). Research Center for Nuclear Physics and Dept. of Physics; Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Hallin, A. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ. (Japan). Research Center for Nuclear Physics and Dept. of Physics; Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Technological Univ., Cookeville, TN (United States); Kochetov, O. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Konovalov, S. I. [Inst. of Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Universities Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ. (China)

    2015-01-01

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.

  19. Confining Backgrounds and Quantum Chaos in Holography

    E-Print Network [OSTI]

    Basu, Pallab

    2013-01-01

    Classical world-sheet string theory has recently been shown to be nonintegrable and chaotic in various confining string theory backgrounds -- the AdS soliton background in particular. In this paper we study a minisuperspace quantization of the theory and look at properties of the spectrum like the distribution of level spacing, which are indicative of quantum order or chaos. In the quantum spectrum we find a gradual transition from chaotic (Wigner GOE) to integrable (Poisson) regime as we look at higher energies. This is expected since our system is integrable asymptotically, and at higher energies, the dynamics is entirely dominated by the kinetic terms.

  20. 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}=1.12±0.61(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}.

  1. PRE-EMPLOYMENT BACKGROUND SCREENS 2. Definitions

    E-Print Network [OSTI]

    Emmons, Scott

    Term Definition Background Check Process of acquiring records regarding a final candidate that are used. Criminal Conviction Being found guilty, entering a guilty plea, or pleading no contest or nolo contendere is considered minor while driving under the influence is major). Disclosures of criminal convictions are subject

  2. Background Information 1. What are stem cells?

    E-Print Network [OSTI]

    Rambaut, Andrew

    Background Information 1. What are stem cells? 2. What might stem cell research achieve? 3. Why we need to continue research using embryonic stem cells? 4. Time taken for discoveries 5. Examples of stem cell therapies in clinical trials 6. Patentability of human embryonic stem cell therapies 7. Creation

  3. Carbon Management and Implementation Plan 1. Background

    E-Print Network [OSTI]

    Chittka, Lars

    by the Carbon Reduction Commitment Energy Efficiency Scheme3 (CRC EES) and the EU Energy Performance in the most cost effective manner on an invest to save basis. Energy costs are projected to rise significantlyCarbon Management and Implementation Plan 1. Background Energy security and the increasing

  4. Yerkes Summer Institute 2002 Introduction & Background

    E-Print Network [OSTI]

    Collar, Juan I.

    a Short Wave (SW) radio signal? What role does wave propagation (the movement of radio waves through don't already know the answers. Background Radio waves are electromagnetic waves and as such are just is broken into various frequencies. Radio waves are found in the Kilohertz (103 Hz) to Megahertz (106 Hz

  5. Risk Estimation; Background Radiation (Natural and Artificial )

    E-Print Network [OSTI]

    Massey, Thomas N.

    . · This is necessary to obtain reasonable statistics on these rare events of radiation effects at low dose is based artificial and natural · response to low-level radiation. · personal background radiation level. #12;An Organism's Response to Radiation · The dose response can be linear or nonlinear and threshold or non

  6. The Polarization of the Cosmic Microwave Background

    E-Print Network [OSTI]

    Matias Zaldarriaga

    2003-05-15

    We summarize the physical mechanism by which the Cosmic Microwave Background acquires a small degree of polarization. We discuss the imprint left by gravitational waves and the use of polarization as a test of the inflationary paradigm. We discuss some physical processes that affect the CMB polarization after recombination such as gravitational lensing and the reionization of the universe.

  7. Cosmic Background Radiation Due to Photon Condensation

    E-Print Network [OSTI]

    B. G. Sidharth

    1998-06-10

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

  8. UCHC Lockout/Tagout Policy Background

    E-Print Network [OSTI]

    Kim, Duck O.

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

  9. Adaptive Background Estimation using Intensity Independent Features

    E-Print Network [OSTI]

    Lunds Universitet

    Adaptive Background Estimation using Intensity Independent Features Håkan Ardö, Rikard Berthilsson to rapid changes in lighting conditions. Furthermore, the features can be computed very efficiently using reliable way, also in outdoor scenes where the lighting conditions is changing rapidly due to passing

  10. Executive Summary 3 Community Background 3

    E-Print Network [OSTI]

    Mlllet, Dylan B.

    to the markets or retail stores, and who do not want to spend their hard-earned money on overpriced, low quality 4 Target Markets 4 Environment Analysis 5 Industry Background 5 Mark-Up of Price 5 Assumptions Marketing Plan 7 Implementation & Expansion 8 Pilot Program: 2 Months 8 Expansion Within New Delhi 8

  11. CHAPTER 1 INTRODUCTION 1.1 Background

    E-Print Network [OSTI]

    O'Connor, Rory

    -platform software development projects. In addressing these aims, this research devised a framework and architecture objectives are to provide a framework that enables the project manager to make reasonable estimates1 CHAPTER 1 INTRODUCTION 1.1 Background This thesis describes a multi-agent based architecture

  12. University of Bristol -Access Agreement 1. Background

    E-Print Network [OSTI]

    Wiesner, Karoline

    1 University of Bristol - Access Agreement 2013 Entry 1. Background The University developed its to the government grant package. The move to a new financial environment in 2012/13 necessitated a more fundamental degree will have to pay the full cost fees (£18,450 a year in 2012/13). #12;2 · Students who are entitled

  13. Cosmic IR Backgrounds Ned Wright (UCLA)

    E-Print Network [OSTI]

    Wright, Edward L. "Ned"

    ://sirtf.caltech.edu #12;Definitions #12;Wide window on the CBR #12;Backgrounds · Microwave ­ the CMB is 10,000 times;Expanding Mirrored Box #12;Ell-to-energy #12;dX-to-energy #12;time-redshift #12;Luminosity density vs to the Sun, the most luminous galaxies in the Universe, and also map the large- scale structure out

  14. CLIMATE AND CLIMATE CHANGE SCIENTIFIC BACKGROUND

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    CLIMATE AND CLIMATE CHANGE SCIENTIFIC BACKGROUND FOR INFORMED DECISION-MAKING Stephen E. Schwartz Climate Research Unit, East Anglia UK #12;INDICATIONS OF SYSTEMATIC WARMING IN RECENT YEARS The 1990s were call the anthropocene climate regime. Over the 20th century, human population quadrupled and energy

  15. 2013 National Geothermal Student Competition Background

    E-Print Network [OSTI]

    Carrington, Emily

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

  16. Yale ME Turbine Test cell instructions Background

    E-Print Network [OSTI]

    Haller, Gary L.

    Yale ME Turbine Test cell instructions Background: The Turbine Technologies Turbojet engine combustion gas backflow into the lab space. Test Cell preparation: 1. Turn on Circuit breakers # 16 of the turbine and check a few items: o Open keyed access door on rear of Turbine enclosure o Check Jet A fuel

  17. Holographic backgrounds from D-brane probes

    E-Print Network [OSTI]

    Micha Moskovic

    2015-01-09

    This thesis focuses on the derivation of holographic backgrounds from the field theory side, without using any supergravity equations of motion. Instead, we rely on the addition of probe D-branes to the stack of D-branes generating the background. From the field theory description of the probe branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the generic probe D-brane action then allows to determine the holographic background dual to the considered field theory vacuum. In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons. The second part contains our original results, which have already appeared in arXiv:1301.3738, arXiv:1301.7062 and arXiv:1312.0621. We first derive the duals to three continuous deformations (Coulomb branch, $\\beta$ and non-commutative deformations) of N=4 super-Yang-Mills. We then derive the enhan\\c{c}on mechanism in a simple N=2 quiver gauge theory setup by using a fractional D-instanton as a probe and exploiting recent exact results on the Coulomb branch of N=2 quivers. Finally, we obtain the near-horizon D4-brane geometry by probing the D4-branes with a small number of D0-branes.

  18. Physical Background OfPhysical Background Of Nuclear Magnetic ResonanceNuclear Magnetic Resonance

    E-Print Network [OSTI]

    Olszewski Jr., Edward A.

    Physical Background OfPhysical Background Of Nuclear Magnetic ResonanceNuclear Magnetic Resonance SpectroscopySpectroscopy Michael McClellan Spring 2009 Department of Physics and Physical Oceanography Theoretically the nucleus can have any of these allowed spins #12;General Characteristics of Nuclear Spin

  19. Foreign Energy Company Competitiveness: Background information

    SciTech Connect (OSTI)

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

    1994-10-01

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

  20. Quantization of exciton in magnetic field background

    E-Print Network [OSTI]

    Pulak Ranjan Giri; S. K. Chakrabarti

    2007-11-22

    The possible mismatch between the theoretical and experimental absorption of the edge peaks in semiconductors in a magnetic field background may arise due to the approximation scheme used to analytically calculate the absorption coefficient. As a possible remedy we suggest to consider nontrivial boundary conditions on x-y plane by in-equivalently quantizing the exciton in background magnetic field. This inequivalent quantization is based on von Neumann's method of self-adjoint extension, which is characterized by a parameter \\Sigma. We obtain bound state solution and scattering state solution, which in general depend upon the self-adjoint extension parameter \\Sigma. The parameter \\Sigma can be used to fine tune the optical absorption coefficient K(\\Sigma) to match with the experiment.

  1. Consistent massive graviton on arbitrary backgrounds

    E-Print Network [OSTI]

    Laura Bernard; Cedric Deffayet; Mikael von Strauss

    2015-05-15

    We obtain the fully covariant linearized field equations for the metric perturbation in the de Rham-Gabadadze-Tolley (dRGT) ghost free massive gravities. For a subset of these theories, we show that the non dynamical metric that appears in the dRGT setup can be completely eliminated leading to the theory of a massive graviton moving in a single metric. This has a mass term which contains non trivial contributions of the space-time curvature. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. The 5 constraints are obtained for a background metric which is arbitrary, i.e. which does not have to obey the background field equations.

  2. Task Force on Cosmic Microwave Background Research

    E-Print Network [OSTI]

    James Bock; Sarah Church; Mark Devlin; Gary Hinshaw; Andrew Lange; Adrian Lee; Lyman Page; Bruce Partridge; John Ruhl; Max Tegmark; Peter Timbie; Rainer Weiss; Bruce Winstein; Matias Zaldarriaga

    2006-04-05

    One of the most spectacular scientific breakthroughs in past decades was using measurements of the fluctuations in the cosmic microwave background (CMB) to test precisely our understanding of the history and composition of the Universe. This report presents a roadmap for leading CMB research to its logical next step, using precision polarization measurements to learn about ultra-high-energy physics and the Big Bang itself.

  3. A background free double beta decay experiment

    E-Print Network [OSTI]

    Ioannis Giomataris

    2010-12-20

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

  4. Introduction ACMs (background) Congruence Monoids Bibliography Arithmetic of Congruence Monoids

    E-Print Network [OSTI]

    Ponomarenko, Vadim

    Introduction ACMs (background) Congruence Monoids Bibliography Arithmetic of Congruence Monoids Meetings January 10, 2013 http://www-rohan.sdsu.edu/vadim/cm.pdf #12;Introduction ACMs (background Montealegre, Ari Tenzer. #12;Introduction ACMs (background) Congruence Monoids Bibliography Standard Notation

  5. SKA synergy with Microwave Background studies

    E-Print Network [OSTI]

    Burigana, Carlo; Baccigalupi, Carlo; Barbosa, Domingos; Blanchard, Alain; De Rosa, Adriano; de Zotti, Gianfranco; Finelli, Fabio; Gruppuso, Alessandro; Jones, Michael; Matarrese, Sabino; Melchiorri, Alessandro; Molinari, Diego; Negrello, Mattia; Paoletti, Daniela; Perrotta, Francesca; Scaramella, Roberto; Trombetti, Tiziana

    2015-01-01

    The extremely high sensitivity and resolution of the Square Kilometre Array (SKA) will be useful for addressing a wide set of themes relevant for cosmology, in synergy with current and future cosmic microwave background (CMB) projects. Many of these themes also have a link with future optical-IR and X-ray observations. We discuss the scientific perspectives for these goals, the instrumental requirements and the observational and data analysis approaches, and identify several topics that are important for cosmology and astrophysics at different cosmic epochs.

  6. Emergence of oscillons in an expanding background

    SciTech Connect (OSTI)

    Farhi, E.; Guth, A. H.; Iqbal, N. [Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Graham, N. [Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Department of Physics, Middlebury College, Middlebury, Vermont 05753 (United States); Rosales, R. R. [Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Stamatopoulos, N. [Department of Physics, Middlebury College, Middlebury, Vermont 05753 (United States)

    2008-04-15

    We consider a (1+1) dimensional scalar field theory that supports oscillons, which are localized, oscillatory, stable solutions to nonlinear equations of motion. We study this theory in an expanding background and show that oscillons now lose energy, but at a rate that is exponentially small when the expansion rate is slow. We also show numerically that a universe that starts with (almost) thermal initial conditions will cool to a final state where a significant fraction of the energy of the universe--on the order of 50%--is stored in oscillons. If this phenomenon persists in realistic models, oscillons may have cosmological consequences.

  7. Microsoft Word - Appendix A_Background.doc

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and MyersHr. Anthony V.How DOESampling2007Background

  8. Paducah Background Factsheet | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment ofOffice|in theLegislativeIComplaintsWeaponsRobertBackground Fact Sheet

  9. Solar Energy Education. Renewable energy: a background text....

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

    a background text. Includes glossary Citation Details In-Document Search Title: Solar Energy Education. Renewable energy: a background text. Includes glossary You are...

  10. SIMULATION STUDY OF BACKGROUND PARTICLES IN THE MUON TELESCOPE...

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

    SIMULATION STUDY OF BACKGROUND PARTICLES IN THE MUON TELESCOPE DETECTOR AT THE STAR EXPERIMENT Matthew Breen Thanks to Dr. Mioduszewski and Yanfang Liu Overview Background ...

  11. 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

  12. Relativistic Spacetime Based on Absolute Background

    E-Print Network [OSTI]

    ChiYi Chen

    2015-09-19

    Based on the consideration of naturalness and physical facts in Einstein's theories of relativity, a nontrivial spacetime physical picture, which has a slight difference from the standard one, is introduced by making a further distinction on the absolute background of spacetime and the relative length or duration of base units of spacetime. In this picture, the coordinate base units in gravity-induced spacetime metric are defined by the standard clock and ruler equipped by the observer, and duplicated onto the every position of the whole universe. In contrast, the proper base units of spacetime in gravitational field are defined by the length and duration of physical events intervals in the same-type standard clock and ruler really located at every position of the universe. In principle, the reading number of the standard clock is counted by the undergone times of unit intervals defined depending on a certain kind of proper events. But the size of the base units of spacetime is essentially depicted by the length of the line segment, which is cut from the absolute background of spacetime by the proper events of unit interval. The effect of gravitation is just to change the length of this segment for base spacetime units. On the basis of such a physical picture of spacetime, in a fairly natural way we re-derive a new classical dynamical equation which satisfies a more realistic and moderately general principle of relativity. To further examine this physical picture including of gravitation and spacetime, we also reinterpret the gravitational redshifts for solar gravity tests.

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

    SciTech Connect (OSTI)

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

    2012-12-01

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

  14. The validity of the Background Field Approximation

    E-Print Network [OSTI]

    R. Parentani

    1997-10-10

    In the absence of a tractable theory of quantum gravity, quantum matter field effects have been so far computed by treating gravity at the Background Field Approximation. The principle aim of this paper is to investigate the validity of this approximation which is not specific to gravity. To this end, for reasons of simplicity and clarity, we shall compare the descriptions of thermal processes induced by constant acceleration (i.e. the Unruh effect) in four dynamical frameworks. In this problem, the position of the ``heavy'' accelerated system plays the role of gravity. In the first framework, the trajectory is treated at the BFA: it is given from the outset and unaffected by radiative processes. In the second one, recoil effects induced by these emission processes are taken into account by describing the system's position by WKB wave functions. In the third one, the accelerated system is described by second quantized fields and in the fourth one, gravity is turned on. It is most interesting to see when and why transitions amplitudes evaluated in different frameworks but describing the same process do agree. It is indeed this comparison that determines the validity of the BFA. It is also interesting to notice that the abandonment of the BFA delivers new physical insights concerning the processes. For instance, in the fourth framework, the ``recoils'' of gravity show that the acceleration horizon area acts as an entropy in delivering heat to accelerated systems.

  15. Schwarzschild black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-09-27

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

  16. Study of alpha background in a dark matter detector

    E-Print Network [OSTI]

    Yegoryan, Hayk

    2010-01-01

    Alpha background, specifically from radon and its progeny in the uranium and thorium chains, has been a major issue in dark matter detectors. This work focuses on alpha background presence in the DMTPC experiment by examining ...

  17. NEAR-MILLIMETER SPECTRUM OF THE MICROWAVE BACKGROUND

    E-Print Network [OSTI]

    Woody, D.P.

    2013-01-01

    +o, 14 z2.06 Table 3. Microwave Measurements of the CMBMILLIMETER SPECTRUM OF THE MICROWAVE BACKGROUND D. P. WoodyMILLIMETER SPECTRUM OF THE MICROWAVE BACKGROUND D. P. Woody1

  18. Passive background correction method for spatially resolved detection

    DOE Patents [OSTI]

    Schmitt, Randal L. (Tijeras, NM); Hargis, Jr., Philip J. (Albuquerque, NM)

    2011-05-10

    A method for passive background correction during spatially or angularly resolved detection of emission that is based on the simultaneous acquisition of both the passive background spectrum and the spectrum of the target of interest.

  19. Systematics of Coupling Flows in AdS Backgrounds

    E-Print Network [OSTI]

    Goldberger, Walter D.

    2009-01-01

    can be calculated using the AdS/CFT correspondence bySystematics of Coupling Flows in AdS Backgrounds Walter D.Systematics of Coupling Flows in AdS Backgrounds Walter D.

  20. Guidance for Environmental Background Analysis Volume III: Groundwater

    E-Print Network [OSTI]

    Guidance for Environmental Background Analysis Volume III: Groundwater Prepared for: Naval This guidance document provides instructions for characterizing groundwater background conditions and comparing datasets representing groundwater impacted by an actual or potential chemical release to appropriate

  1. Muon-induced backgrounds in the CUORICINO experiment

    E-Print Network [OSTI]

    Andreotti, E.

    2010-01-01

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

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

    Office of Scientific and Technical Information (OSTI)

    English Subject: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; BACKGROUND RADIATION; COSMOLOGICAL MODELS; COSMOLOGY; DAMPING; DATASETS; DETECTION; FLUCTUATIONS; GHZ...

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

    Office of Scientific and Technical Information (OSTI)

    79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; BACKGROUND RADIATION; COSMOLOGY; DETECTION; EV RANGE; FLUCTUATIONS; GALAXY CLUSTERS; HELIUM; INDEXES; LIMITING VALUES;...

  4. Discovering Tau and Muon Solar Neutrino Flares above backgrounds

    E-Print Network [OSTI]

    D. Fargion; F. Moscato

    2004-07-11

    Solar neutrino flares astronomy is at the edge of its discover. High energy flare particles (protons, alpha) whose self scattering within the solar corona is source of a rich prompt charged pions are also source of sharp solar neutrino "burst" (at tens-hundred MeV) produced by their pion-muon primary decay in flight. This brief (minute) solar neutrino "burst" at largest peak overcome by four-five order of magnitude the steady atmospheric neutrino noise at the Earth. Later on, solar flare particles hitting the terrestrial atmosphere may marginally increase the atmospheric neutrino flux without relevant consequences. Largest prompt "burst" solar neutrino flare may be detected in present or better in future largest neutrino underground neutrino detectors. Our estimate for the recent and exceptional October - November 2003 solar flares gives a number of events above or just near unity for Super-Kamiokande. The neutrino spectra may reflect in a subtle way the neutrino flavour mixing in flight. A surprising tau appearance may even occur for a hard ({E}_{nu}_{mu}--> {E}_{nu}_{tau} > 4 GeV) flare spectra. A comparison of the solar neutrino flare (at their birth place on Sun and after oscillation on the arrival on the Earth) with other neutrino foreground is here described and it offer an independent road map to disentangle the neutrino flavour puzzles and its secret flavour mixing angles .

  5. Background Main Result Mechanism Design Properties General Characterizations of Truthfulness

    E-Print Network [OSTI]

    Chen, Yiling

    Background Main Result Mechanism Design Properties General Characterizations of Truthfulness via November 29, 2012 Joint work with Ian Kash (MSRC) #12;Background Main Result Mechanism Design Properties Ian Says Hi! #12;Background Main Result Mechanism Design Properties Warm-up: Convex Functions y

  6. Composition of the Fermi-LAT isotropic gamma-ray background intensity: Emission from extragalactic point sources and dark matter annihilations

    E-Print Network [OSTI]

    Mattia Di Mauro; Fiorenza Donato

    2015-06-14

    A new estimation of the isotropic diffuse gamma-ray background (IGRB) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) has been presented for 50 months of data, in the energy range 100 MeV-820 GeV and for different modelings of the Galactic foreground. We attempt here the interpretation of the Fermi-LAT IGRB data in terms of the gamma-ray unresolved emission from different extragalactic populations. We find very good fits to the experimental IGRB, obtained with theoretical predictions for the emission from active galactic nuclei and star-forming galaxies. In addition, we probe a possible emission coming from the annihilation of weakly interacting dark matter (DM) particles in the halo of our Galaxy. We set stringent limits on its annihilation cross section into gamma rays, which are about the thermal relic value for a wide range of DM masses. We also identify regions in the DM mass and annihilation cross section parameter space which can significantly improve the fit to the IGRB data. Our analysis is conducted within the different IGRB data sets obtained from different models for the Galactic emission, which is shown to add a significant ambiguity on the IGRB interpretation.

  7. Noncommutative Black-Body Radiation: Implications On Cosmic Microwave Background

    E-Print Network [OSTI]

    Amir H. Fatollahi; Maryam Hajirahimi

    2006-07-12

    Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space noncommutativity on the Cosmic Microwave Background map is argued.

  8. Neutron Spallation Measurements And Impacts On Low Background Experiments

    SciTech Connect (OSTI)

    Aguayo, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

    2014-09-01

    Ultra-low background experiments, such as neutrinoless double beta decay, carried out deep underground to escape cosmic ray backgrounds can nonetheless be limited in sensitivity by cosmogenically induced signals. This limit can either be produced directly during operation from cosmic muon events in the detector volume, or can be produced by radioactive decay of cosmogenically generated radionuclides created while the detector materials were above ground. An accurate knowledge of the production of the latter source of background is of paramount importance in order to be able to interpret the results of low-background experiments.

  9. Diffraction Dissociation at the LHC; Role of the Background

    SciTech Connect (OSTI)

    Jenkovszky, L. L.; Kuprash, O. E.; Magas, V. K.

    2011-07-15

    We discuss two topical problems of diffraction dissociation at the LHC, namely the role of the background and the elastic contribution.

  10. Performance Oversight Group: Background and Guidelines for Presenters

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

    Group: Background and Guidelines for Presenters Carl Strawbridge Office of Integrated Planning and Performance Management (formerly OPPS) Dean Hoffer Office of Project Support...

  11. Astroparticle physics with a customized low-background broad...

    Office of Scientific and Technical Information (OSTI)

    low-background broad energy Germanium detector The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in...

  12. Neutron inelastic scattering in natural Pb as a background in...

    Office of Scientific and Technical Information (OSTI)

    Neutron inelastic scattering in natural Pb as a background in neutrinoless double-beta decay experiments Citation Details In-Document Search Title: Neutron inelastic scattering in...

  13. ESnet supports Sandia and APNIC IPv6 Background Radiation research

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

    IPv6 Network IPv6 Implementation Checklist ESnet IPv6 Mirror Servers ESnet IPv6 History ESnet supports Sandia and APNIC IPv6 Background Radiation research Network...

  14. Background Long history of research and education in "nuclear

    E-Print Network [OSTI]

    Lemurell, Stefan

    #12;Background · Long history of research and education in "nuclear engineering" at Chalmers. · "Nuclear engineering" = multi-disciplinary research area. #12;Background Establishment of the Sustainable Nuclear Energy Centre (SNEC) on January 31, 2012. Prof. Christophe Demaziere SNEC director Prof. Christian

  15. An electronic radiation of blackbody: Cosmic electron background

    E-Print Network [OSTI]

    Jian-Miin Liu

    2008-02-23

    The Universe owns the electronic radiation of blackbody at temperature 2.725 K, which we call the cosmic electron background. We calculate its radiation spectrum. The energy distribution of number density of electrons in the cosmic electron background becomes zero as energy goes to both zero and infinity. It has one maximum peak near the energy level of 10**(-23) J.

  16. Effects of the UV background radiation on galaxy formation

    E-Print Network [OSTI]

    Masahiro Nagashima; Naoteru Gouda; Norimasa Sugiura

    1999-06-10

    We investigate the effects of the UV background radiation on galaxy formation by using the semi-analytic model including the photoionization process. The semi-analytic model is based on Cole et al. (1994) and we use almost the same parameters of their `fiducial' model. We find that the UV background mainly affects the formation of dwarf galaxies. Because of the suppression of star formation, the number density of small objects corresponding to dwarf galaxies decreases compared to the case of no UV radiation when the UV background exists until the present epoch. When the UV background vanishes at a low redshift, the number density of small objects is hardly changed but the colour becomes bluer, compared to the case of no UV radiation, because stars are newly formed after the UV background vanishes. On the other hand, the UV radiation hardly affects massive galaxies. This is because the massive galaxies are formed by mergers of small galaxies.

  17. Radon-related backgrounds in the LUX dark matter search

    SciTech Connect (OSTI)

    Bradley, A. [Case Western Reserve Univ., Cleveland, OH (United States); Akerib, D. S. [Case Western Reserve Univ., Cleveland, OH (United States); Araújo, H. M. [Imperial College London, London (United Kingdom); Bai, X. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Bailey, A. J. [Imperial College London, London (United Kingdom); Balajthy, J. [Univ. of Maryland, College Park, MD (United States); Bernard, E. [Yale Univ., New Haven, CT (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Cahn, S. B. [Yale Univ., New Haven, CT (United States); Carmona-Benitez, M. C. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Chan, C. [Brown Univ., Providence, RI (United States); Chapman, J. J. [Brown Univ., Providence, RI (United States); Chiller, A. A. [Univ. of South Dakota, Vermillion, SD (United States); Chiller, C. [Univ. of South Dakota, Vermillion, SD (United States); Coffey, T. [Case Western Reserve Univ., Cleveland, OH (United States); Currie, A. [Imperial College London, London (United Kingdom); de Viveiros, L. [Univ. of Coimbra, Coimbra (Portugal); Dobi, A. [Univ. of Maryland, College Park, MD (United States); Dobson, J. [Univ. of Edingburg, Edinburg (United Kingdom); Druszkiewicz, E. [Univ. of Rochester, Rochester, NY (United States); Edwards, B. [Yale Univ., New Haven, CT (United States); Faham, C. H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fiorucci, S. [Brown Univ., Providence, RI (United States); Flores, C. [Univ. of California, Davis, Davis, CA (United States); Gaitskell, R. J. [Brown Univ., Providence, RI (United States); Gehman, V. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghag, C. [Univ. College London, London (United Kingdom); Gibson, K. R. [Case Western Reserve Univ., Cleveland, OH (United States); Gilchriese, M. G.D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hall, C. [Univ. of Maryland, College Park, MD (United States); Hertel, S. A. [Yale Univ., New Haven, CT (United States); Horn, M. [Yale Univ., New Haven, CT (United States); Huang, D. Q. [Brown Univ., Providence, RI (United States); Ihm, M. [Univ. of California Berkeley, Berkeley, CA (United States); Jacobsen, R. G. [Univ. of California Berkeley, Berkeley, CA (United States); Kazkaz, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knoche, R. [Univ. of Maryland, College Park, MD (United States); Larsen, N. A. [Yale Univ., New Haven, CT (United States); Lee, C. [Case Western Reserve Univ., Cleveland, OH (United States); Lindote, A. [Univ. of Coimbra, Coimbra (Portugal); Lopes, M. I. [Univ. of Coimbra, Coimbra (Portugal); Malling, D. C. [Brown Univ., Providence, RI (United States); Mannino, R. [Texas A & M Univ., College Station, TX (United States); McKinsey, D. N. [Yale Univ., New Haven, CT (United States); Mei, D. -M. [Univ. of South Dakota, Vermillion, SD (United States); Mock, J. [Univ. of California, Davis, Davis, CA (United States); Moongweluwan, M. [Univ. of Rochester, Rochester, NY (United States); Morad, J. [Univ. of California, Davis, Davis, CA (United States); Murphy, A. St.J. [Univ. of Edingburg, Edinburg (United Kingdom); Nehrkorn, C. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Nelson, H. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Neves, F. [Univ. of Coimbra, Coimbra (Portugal); Ott, R. A. [Univ. of California, Davis, Davis, CA (United States); Pangilinan, M. [Brown Univ., Providence, RI (United States); Parker, P. D. [Yale Univ., New Haven, CT (United States); Pease, E. K. [Yale Univ., New Haven, CT (United States); Pech, K. [Case Western Reserve Univ., Cleveland, OH (United States); Phelps, P. [Case Western Reserve Univ., Cleveland, OH (United States); Reichhart, L. [Univ. College London, London (United Kingdom); Shutt, T. [Case Western Reserve Univ., Cleveland, OH (United States); Silva, C. [Univ. of Coimbra, Coimbra (Portugal)

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily tagged and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.

  18. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    Ashenfelter, J; Baldenegro, C X; Band, H R; Barclay, G; Bass, C D; Berish, D; Bowden, N S; Bryan, C D; Cherwinka, J J; Chu, R; Classen, T; Davee, D; Dean, D; Deichert, G; Dolinski, M J; Dolph, J; Dwyer, D A; Fan, S; Gaison, J K; Galindo-Uribarri, A; Gilje, K; Glenn, A; Green, M; Han, K; Hans, S; Heeger, K M; Heffron, B; Jaffe, D E; Kettell, S; Langford, T J; Littlejohn, B R; Martinez, D; McKeown, R D; Morrell, S; Mueller, P E; Mumm, H P; Napolitano, J; Norcini, D; Pushin, D; Romero, E; Rosero, R; Saldana, L; Seilhan, B S; Sharma, R; Stemen, N T; Surukuchi, P T; Thompson, S J; Varner, R L; Wang, W; Watson, S M; White, B; White, C; Wilhelmi, J; Williams, C; Wise, T; Yao, H; Yeh, M; Yen, Y -R; Zhang, C; Zhang, X

    2015-01-01

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  19. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    J. Ashenfelter; B. Balantekin; C. X. Baldenegro; H. R. Band; G. Barclay; C. D. Bass; D. Berish; N. S. Bowden; C. D. Bryan; J. J. Cherwinka; R. Chu; T. Classen; D. Davee; D. Dean; G. Deichert; M. J. Dolinski; J. Dolph; D. A. Dwyer; S. Fan; J. K. Gaison; A. Galindo-Uribarri; K. Gilje; A. Glenn; M. Green; K. Han; S. Hans; K. M. Heeger; B. Heffron; D. E. Jaffe; S. Kettell; T. J. Langford; B. R. Littlejohn; D. Martinez; R. D. McKeown; S. Morrell; P. E. Mueller; H. P. Mumm; J. Napolitano; D. Norcini; D. Pushin; E. Romero; R. Rosero; L. Saldana; B. S. Seilhan; R. Sharma; N. T. Stemen; P. T. Surukuchi; S. J. Thompson; R. L. Varner; W. Wang; S. M. Watson; B. White; C. White; J. Wilhelmi; C. Williams; T. Wise; H. Yao; M. Yeh; Y. -R. Yen; C. Zhang; X. Zhang

    2015-06-11

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  20. Background Radiation Measurements at High Power Research Reactors

    E-Print Network [OSTI]

    J. Ashenfelter; B. Balantekin; C. X. Baldenegro; H. R. Band; G. Barclay; C. D. Bass; D. Berish; N. S. Bowden; C. D. Bryan; J. J. Cherwinka; R. Chu; T. Classen; D. Davee; D. Dean; G. Deichert; M. J. Dolinski; J. Dolph; D. A. Dwyer; S. Fan; J. K. Gaison; A. Galindo-Uribarri; K. Gilje; A. Glenn; M. Green; K. Han; S. Hans; K. M. Heeger; B. Heffron; D. E. Jaffe; S. Kettell; T. J. Langford; B. R. Littlejohn; D. Martinez; R. D. McKeown; S. Morrell; P. E. Mueller; H. P. Mumm; J. Napolitano; D. Norcini; D. Pushin; E. Romero; R. Rosero; L. Saldana; B. S. Seilhan; R. Sharma; N. T. Stemen; P. T. Surukuchi; S. J. Thompson; R. L. Varner; W. Wang; S. M. Watson; B. White; C. White; J. Wilhelmi; C. Williams; T. Wise; H. Yao; M. Yeh; Y. -R. Yen; C. Zhang; X. Zhang

    2015-11-11

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including $\\gamma$-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  1. Radon-related backgrounds in the LUX dark matter search

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

    Bradley, A.; Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Byram, D.; Cahn, S. B.; et al

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily taggedmore »and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.« less

  2. Initial Beta-Gamma Nuclear Detector Background Study

    SciTech Connect (OSTI)

    Cooper, Matthew W.; Aalseth, Craig E.; Haas, Derek A.; Hayes, James C.

    2011-09-12

    Detection of underground nuclear explosions and, more recently, nuclear reactor events is of great national interest. These measurements are most often made by determining the concentration of radioactive noble gases in the atmosphere. Currently there are several ground-based systems capable of making radioxenon gas measurements. The measurement is often close to the detection limit, so understanding the parameters and features that limit the measurement is very important. A preliminary study of the detection limit has been performed using a ?-? Quad detector designed at Pacific Northwest National Laboratory (PNNL). The initial study has concentrated on the measuring the ambient radioactive background. By making several background measurements while varying the detector, shielding it is possible to identify whether the ambient background is internal or external to the detector. Furthermore, internal background contributions can be potentially reduced by selecting alternative low-background materials, while external background can be reduced by increasing the active or passive shielding present. By reducing the background contributions, it is possible to improve the detection limit and therefore the likelihood of positively identifying a nuclear test.

  3. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    E-Print Network [OSTI]

    I. Guinn; N. Abgrall; I. J. Arnquist; F. T. Avignone III; C. X. Baldenegro-Barrera; A. S. Barabash; F. E. Bertrand; A. W. Bradley; V. Brudanin; M. Busch; M. Buuck; D. Byram; A. S. Caldwell; Y-D. Chan; C. D. Christofferson; C. Cuesta; J. A. Detwiler; Yu. Efremenko; H. Ejiri; S. R. Elliott; A. Galindo-Uribarri; T. Gilliss; G. K. Giovanetti; J. Goett; M. P. Green; J. Gruszko; V. E. Guiseppe; R. Henning; E. W. Hoppe; S. Howard; M. A. Howe; B. R. Jasinski; K. J. Keeter; M. F. Kidd; S. I. Konovalov; R. T. Kouzes; B. D. LaFerriere; J. Leon; J. MacMullin; R. D. Martin; S. J. Meijer; S. Mertens; J. L. Orrell; C. O'Shaughnessy; A. W. P. Poon; D. C. Radford; J. Rager; K. Rielage; R. G. H. Robertson; E. Romero-Romero; B. Shanks; M. Shirchenko; N. Snyder; A. M. Suriano; D. Tedeschi; J. E. Trimble; R. L. Varner; S. Vasilyev; K. Vetter; K. Vorren; B. R. White; J. F. Wilkerson; C. Wiseman; W. Xu; E. Yakushev; C. -H. Yu; V. Yumatov; I. Zhitnikov

    2015-06-13

    The MAJORANA Collaboration will seek neutrinoless double beta decay (0nbb) in 76Ge using isotopically enriched p-type point contact (PPC) high purity Germanium (HPGe) detectors. A tonne-scale array of HPGe detectors would require background levels below 1 count/ROI-tonne-year in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the decay. In order to demonstrate the feasibility of such an experiment, the MAJORANA DEMONSTRATOR, a 40 kg HPGe detector array, is being constructed with a background goal of design used to construct signal readout electronics with low enough backgrounds for the MAJORANA DEMONSTRATOR.

  4. Low Background Signal Readout Electronics for the MAJORANA DEMONSTRATOR

    E-Print Network [OSTI]

    Guinn, I; Arnquist, I J; Avignone, F T; Baldenegro-Barrera, C X; Barabash, A S; Bertrand, F E; Bradley, A W; Brudanin, V; Busch, M; Buuck, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Cuesta, C; Detwiler, J A; Efremenko, Yu; Ejiri, H; Elliott, S R; Galindo-Uribarri, A; Gilliss, T; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guiseppe, V E; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Jasinski, B R; Keeter, K J; Kidd, M F; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; MacMullin, J; Martin, R D; Meijer, S J; Mertens, S; Orrell, J L; O'Shaughnessy, C; Poon, A W P; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Shanks, B; Shirchenko, M; Snyder, N; Suriano, A M; Tedeschi, D; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Yu, C -H; Yumatov, V; Zhitnikov, I

    2015-01-01

    The MAJORANA Collaboration will seek neutrinoless double beta decay (0nbb) in 76Ge using isotopically enriched p-type point contact (PPC) high purity Germanium (HPGe) detectors. A tonne-scale array of HPGe detectors would require background levels below 1 count/ROI-tonne-year in the 4 keV region of interest (ROI) around the 2039 keV Q-value of the decay. In order to demonstrate the feasibility of such an experiment, the MAJORANA DEMONSTRATOR, a 40 kg HPGe detector array, is being constructed with a background goal of design used to construct signal readout electronics with low enough backgrounds for the MAJORANA DEMONSTRATOR.

  5. SNAP sky background at the north ecliptic pole

    SciTech Connect (OSTI)

    Aldering, Greg

    2002-07-01

    I summarize the extant direct and indirect data on the sky background SNAP will see at the North Ecliptic Pole over the wavelength range 0.4 < {lambda} < 1.7 {micro}m. At the spatial resolution of SNAP the sky background due to stars and galaxies is resolved, so the only source considered is zodiacal light. Several models are explored to provide interpolation in wavelength between the broadband data from HST and COBE observations. I believe the input data are now established well enough that the accuracy of the sky background presented here is sufficient for SNAP simulations, and that it will stand up to scrutiny by reviewers.

  6. CLIC Background Studies and optimization of the innermost tracker elements

    E-Print Network [OSTI]

    D. Dannheim; A. Sailer; J. Trenado; M. Vos

    2012-03-05

    The harsh machine background at the Compact Linear Collider (CLIC) forms a strong constraint on the design of the innermost part of the tracker. For the CLIC Conceptual Design Report, the detector concepts developed for the International Linear Collider (ILC) were adapted to the CLIC environment. We present the new layout for the Vertex Detector and the Forward Tracking Disks of the CLIC detector concepts, as well as the background levels in these detectors. We also study the dependence of the background rates on technology parameters like thickness of the active layer and detection threshold.

  7. Characterization of dipping fractures in transversely isotropic background

    E-Print Network [OSTI]

    Tsvankin, Ilya

    Characterization of dipping fractures in transversely isotropic background Vladimir Grechka incidence becomes dependent on fracture infill (saturation). A complete medium-characterization procedure for the vertical and NMO velocities. Keywords.--fracture characterization, azimuthal anisotropy, multicomponent

  8. Analysis techniques for background rejection at the MAJORANA DEMONSTRATOR

    E-Print Network [OSTI]

    Cuesta, C; Arnquist, I J; Avignone, F T; Baldenegro-Barrera, C X; Barabash, A S; Bertrand, F E; Bradley, A W; Brudanin, V; Busch, M; Buuck, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Detwiler, J A; Efremenko, Yu; Ejiri, H; Elliott, S R; Galindo-Uribarri, A; Gilliss, T; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guinn, I S; Guiseppe, V E; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Jasinski, B R; Keeter, K J; Kidd, M F; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; MacMullin, J; Martin, R D; Meijer, S J; Mertens, S; Orrell, J L; O'Shaughnessy, C; Poon, A W P; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Shanks, B; Shirchenko, M; Snyder, N; Suriano, A M; Tedeschi, D; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Yu, C -H; Yumatov, V; Zhitnikov, I

    2015-01-01

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40-kg modular HPGe detector array to search for neutrinoless double beta decay in 76Ge. In view of the next generation of tonne-scale Ge-based 0nbb-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR 0s germanium detectors allows for significant reduction of gamma background.

  9. Superluminal Velocity of Photons in a Gravitational Background

    E-Print Network [OSTI]

    I. B. Khriplovich

    1994-11-20

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

  10. Reduction of background clutter in structured lighting systems

    DOE Patents [OSTI]

    Carlson, Jeffrey J.; Giles, Michael K.; Padilla, Denise D.; Davidson, Jr., Patrick A.; Novick, David K.; Wilson, Christopher W.

    2010-06-22

    Methods for segmenting the reflected light of an illumination source having a characteristic wavelength from background illumination (i.e. clutter) in structured lighting systems can comprise pulsing the light source used to illuminate a scene, pulsing the light source synchronously with the opening of a shutter in an imaging device, estimating the contribution of background clutter by interpolation of images of the scene collected at multiple spectral bands not including the characteristic wavelength and subtracting the estimated background contribution from an image of the scene comprising the wavelength of the light source and, placing a polarizing filter between the imaging device and the scene, where the illumination source can be polarized in the same orientation as the polarizing filter. Apparatus for segmenting the light of an illumination source from background illumination can comprise an illuminator, an image receiver for receiving images of multiple spectral bands, a processor for calculations and interpolations, and a polarizing filter.

  11. Modeling surface backgrounds from radon progeny plate-out

    SciTech Connect (OSTI)

    Perumpilly, G.; Guiseppe, V. E.; Snyder, N. [University of South Dakota, Vermillion, South Dakota 57069 (United States)] [University of South Dakota, Vermillion, South Dakota 57069 (United States)

    2013-08-08

    The next generation low-background detectors operating deep underground aim for unprecedented low levels of radioactive backgrounds. The surface deposition and subsequent implantation of radon progeny in detector materials will be a source of energetic background events. We investigate Monte Carlo and model-based simulations to understand the surface implantation profile of radon progeny. Depending on the material and region of interest of a rare event search, these partial energy depositions can be problematic. Motivated by the use of Ge crystals for the detection of neutrinoless double-beta decay, we wish to understand the detector response of surface backgrounds from radon progeny. We look at the simulation of surface decays using a validated implantation distribution based on nuclear recoils and a realistic surface texture. Results of the simulations and measured ? spectra are presented.

  12. Quantum dynamics of scalar bosons in a cosmic string background

    E-Print Network [OSTI]

    Luis B. Castro

    2015-06-30

    The quantum dynamics of scalar bosons embedded in the background of a cosmic string is considered. In this work, scalar bosons are described by the Duffin-Kemmer-Petiau (DKP) formalism. In particular, the effects of this topological defect in the equation of motion, energy spectrum and DKP spinor are analyzed and discussed in details. The exact solutions for the DKP oscillator in this background are presented in a closed form.

  13. Holographic superconductor developed in BTZ black hole background with backreactions

    E-Print Network [OSTI]

    Yunqi Liu; Qiyuan Pan; Bin Wang

    2011-06-22

    We develop a holographic superconductor in BTZ black hole background with backreactions. We investigate the influence of the backreaction on the condensation of the scalar hair and the dynamics of perturbation in the background spacetime. When the Breitenlohner-Freedman bound is approached, we argue that only one of two possible operators can reflect the real property of the condensation in the holographic superconductor. This argument is supported by the investigation in dynamics.

  14. Possible background reductions in double beta decay experiments

    E-Print Network [OSTI]

    R. Arnold; C. Augier; J. Baker; A. Barabash; O. Bing; V. Brudanin; A. J. Caffrey; E. Caurier; K. Errahmane; A. -I. Etienvre; J. L. Guyonnet; F. Hubert; Ph. Hubert; C. Jollet; S. Jullian; O. Kochetov; V. Kovalenko; D. Lalanne; F. Leccia; C. Longuemare; Ch. Marquet; F. Mauger; H. W. Nicholson; H. Ohsumi; F. Piquemal; J-L. Reyss; X. Sarazin; Yu. Shitov; L. Simard; I. Stekl; J. Suhonen; C. S. Sutton; G. Szklarz; V. Timkin; V. Tretyak; V. Umatov; L. Vala; I. Vanyushin; V. Vasilyev; V. Vorobel; Ts. Vylov

    2003-02-19

    The background induced by radioactive impurities of $^{208}\\rm Tl$ and $^{214}\\rm Bi$ in the source of the double beta experiment NEMO-3 has been investigated. New methods of data analysis which decrease the background from the above mentioned contamination are identified. The techniques can also be applied to other double beta decay experiments capable of measuring independently the energies of the two electrons.

  15. Air fluidized balls in a background of smaller beads

    E-Print Network [OSTI]

    M. E. Beverland; L. J. Daniels; D. J. Durian

    2010-12-02

    We report on quasi-two-dimensional granular systems in which either one or two large balls is fluidized by an upflow of air in the presence of a background of several hundred smaller beads. A single large ball is observed to propel ballistically in nearly circular orbits, in direct contrast to the Brownian behavior of a large ball fluidized in the absence of this background. Further, the large ball motion satisfies a Langevin equation with an additional speed-dependent force acting in the direction of motion. This results in a non-zero average speed of the large ball that is an order of magnitude faster than the root mean square speed of the background balls. Two large balls fluidized in the absence of the small-bead background experience a repulsive force depending only on the separation of the two balls. With the background beads present, by contrast, the ball-ball interaction becomes velocity-dependent and attractive. The attraction is long-ranged and inconsistent with a depletion model; instead, it is mediated by local fluctuations in the density of the background beads which depends on the large balls' motion.

  16. Background reduction and sensitivity for germanium double beta decay experiments

    E-Print Network [OSTI]

    H. Gómez; S. Cebrián; J. Morales; J. A. Villar

    2007-08-29

    Germanium detectors have very good capabilities for the investigation of rare phenomena like the neutrinoless double beta decay. Rejection of the background entangling the expected signal is one primary goal in this kind of experiments. Here, the attainable background reduction in the energy region where the neutrinoless double beta decay signal of 76Ge is expected to appear has been evaluated for experiments using germanium detectors, taking into consideration different strategies like the granularity of the detector system, the segmentation of each individual germanium detector and the application of Pulse Shape Analysis techniques to discriminate signal from background events. Detection efficiency to the signal is affected by background rejection techniques, and therefore it has been estimated for each of the background rejection scenarios considered. Finally, conditions regarding crystal mass, radiopurity, exposure to cosmic rays, shielding and rejection capabilities are discussed with the aim to achieve a background level of 10-3 c keV-1 kg-1 y-1 in the region of interest, which would allow to explore neutrino effective masses around 40 meV.

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

    E-Print Network [OSTI]

    Aslanyan, Grigor; Aslanyan, Grigor

    2012-01-01

    Finding Topology with the Microwave Background Radiation,Lensing of the Cosmic Microwave Background using cross-correlations in the cosmic microwave background, Nature.

  18. Late Time Neutrino Masses, the LSND Experiment and the Cosmic Microwave Background

    E-Print Network [OSTI]

    Chacko, Z.

    2009-01-01

    Experiment and the Cosmic Microwave Background Z. Chacko,Experiment and the Cosmic Microwave Background Z. Chacko,distributions of the cosmic microwave background. arXiv:hep-

  19. Background independent exact renormalization group for conformally reduced gravity

    E-Print Network [OSTI]

    Juergen A. Dietz; Tim R. Morris

    2015-04-27

    Within the conformally reduced gravity model, where the metric is parametrised by a function $f(\\phi)$ of the conformal factor $\\phi$, we keep dependence on both the background and fluctuation fields, to local potential approximation and $\\mathcal{O}(\\partial^2)$ respectively, making no other approximation. Explicit appearances of the background metric are then dictated by realising a remnant diffeomorphism invariance. The standard non-perturbative Renormalization Group (RG) scale $k$ is inherently background dependent, which we show in general forbids the existence of RG fixed points with respect to $k$. By utilising transformations that follow from combining the flow equations with the modified split Ward identity, we uncover a unique background independent notion of RG scale, $\\hat k$. The corresponding RG flow equations are then not only explicitly background independent along the entire RG flow but also explicitly independent of the form of $f$. In general $f(\\phi)$ is forced to be scale dependent and needs to be renormalised, but if this is avoided then $k$-fixed points are allowed and furthermore they coincide with $\\hat k$-fixed points.

  20. Background Simulation Experiment Conclusion Hysteresis in the Nonlinear Tunnelling of Light

    E-Print Network [OSTI]

    Petta, Jason

    Background Simulation Experiment Conclusion Hysteresis in the Nonlinear Tunnelling of Light Through of Light Through a Barrier #12;Background Simulation Experiment Conclusion Outline 1 Background Nonlinear of Light Through a Barrier #12;Background Simulation Experiment Conclusion Nonlinear Optics Nonlinear

  1. Searching for a Stochastic Background of Gravitational Waves with LIGO

    E-Print Network [OSTI]

    Abbott, R; Agresti, J; Ajith, P; Allen, B; Amin, R; Anderson, S B; Anderson, W G; Araya, M; Armandula, H; Ashley, M; Aston, S; Aulbert, C; Babak, S; Ballmer, S; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bayer, K; Belczynski, K; Betzwieser, J; Beyersdorf, P; Bhawal, B; Bilenko, I A; Billingsley, G; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bogue, L; Bork, R; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brooks, A; Brown, D A; Bullington, A; Bunkowski, A; Buonanno, A; Burman, R; Busby, D; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cantley, C A; Cao, J; Cardenas, L; Casey, M M; Cepeda, C; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Chin, D; Chin, E; Chow, J; Christensen, N; Cokelaer, T; Colacino, C N; Coldwell, R; Cook, D; Corbitt, T; Coward, D; Coyne, D; Creighton, J D E; Creighton, T D; Crooks, D R M; Cruise, A M; Cumming, A; Cutler, C; Dalrymple, J; D'Ambrosio, E; Danzmann, K; Davies, G; De Vine, G; De Bra, D; Degallaix, J; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S V; Di Credico, A; Dickson, J; Diederichs, G; Dietz, A; Doomes, E E; Drever, R W P; Dumas, J C; Dupuis, R J; Ehrens, P; Elliffe, E; Etzel, T; Evans, M; Evans, T; Fairhurst, S; Fan, Y; Fejer, M M; Finn, L S; Fotopoulos, N; Franzen, A; Franzen, K Y; Frey, R E; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Goda, K; Goetz, E; Goggin, L; González, G; Gossler, S; Grant, A; Gras, S; Gray, C; Gray, M; Greenhalgh, J; Gretarsson, A M; Grimmett, D; Grosso, R; Grote, H; Grünewald, S; Günther, M; Gustafson, R; Hage, B; Hanna, C; Hanson, J; Hardham, C; Harms, J; Harry, G; Harstad, E; Hayler, T; Heefner, J; Heng, I S; Heptonstall, A; Heurs, M; Hewitson, M; Hild, S; Hindman, N; Hirose, E; Hoak, D; Hoang, P; Hosken, D; Hough, J; Howell, E; Hoyland, D; Hua, W; Huttner, S; Ingram, D; Ito, M; Itoh, Y; Ivanov, A; Jackrel, D; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Khalili, F Ya; Khan, A; Kim, C; King, P; Klimenko, S; Kokeyama, K; Kondrashov, V; Koranda, S; Kozak, D; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lantz, B; Lazzarini, A; Lee, B; Lei, M; Leonhardt, V; Leonor, I; Libbrecht, K; Lindquist, P; Lockerbie, N A; Lormand, M; Lubinski, M; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Malec, M; Mandic, V; Marka, S; Markowitz, J; Maros, E; Martin, I; Marx, J N; Mason, K; Matone, L; Mavalvala, N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McKenzie, K; McNabb, J W C; Meier, T; Melissinos, A C; Mendell, G; Mercer, R A; Meshkov, S; Messaritaki, E; Messenger, C J; Meyers, D; Mikhailov, E; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Moylan, A; Mudge, D; Müller, G; Müller-Ebhardt, H; Mukherjee, S; Munch, J; Murray, P; Myers, E; Myers, J; Newton, G; Numata, K; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Overmier, H; Owen, B J; Pan, Y; Papa, M A; Parameshwaraiah, V; Pedraza, M; Penn, S; Pitkin, M; Plissi, M V; Prix, R; Quetschke, V; Raab, F; Rabeling, D; Radkins, H; Rahkola, R; Rakhmanov, M; Rawlins, K; Ray-Majumder, S; Re, V; Rehbein, H; Reid, S; Reitze, D H; Ribichini, L; Riesen, R; Riles, K; Rivera, B; Robertson, D I; Robertson, N A; Robinson, C; Roddy, S; Rodríguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sanchodela-Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Schediwy, S; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Seader, S E; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Sheard, B; Shoemaker, D H; Sibley, A; Siemens, X; Sigg, D; Sintes, A M; Slagmolen, B; Slutsky, J; Smith, J; Smith, M R; Sneddon, P; Somiya, K; Speake, C; Spjeld, O; Strain, K A; Strom, D M; Stuver, A; Summerscales, T; Sun, K; Sung, M; Sutton, P J; Tanner, D B; Tarallo, M; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D W; Ungarelli, C; Vahlbruch, H; Vallisneri, M; Varvella, M; Vass, S; Vecchio, A; Veitch, J; Veitch, P; Vigeland, S; Villar, A; Vorvick, C; Vyachanin, S P; Waldman, S J; Wallace, L; Ward, H; Ward, R; Watts, K; Webber, D; Weidner, A; Weinstein, A; Weiss, R; Wen, S; Wette, K; Whelan, J T; Whitbeck, D M; Whitcomb, S E; Whiting, B F; Wilkinson, C; Willems, P A; Willke, B; Wilmut, I; Winkler, W; Wipf, C C; Wise, S; Wiseman, A G; Woan, G; Woods, D; Wooley, R; Worden, J; Wu, W; Yakushin, I; Yamamoto, H; Yan, Z; Yoshida, S; Yunes, N; Zanolin, M; Zhang, L; Zhao, C; Zotov, N P; Zucker, M; Zur Mühlen, H

    2006-01-01

    The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\\Omega_{\\rm GW} < 6.5 \\times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.

  2. The local potential approximation in the background field formalism

    E-Print Network [OSTI]

    I. Hamzaan Bridle; Juergen A. Dietz; Tim R. Morris

    2014-03-20

    Working within the familiar local potential approximation, and concentrating on the example of a single scalar field in three dimensions, we show that the commonly used approximation method of identifying the total and background fields, leads to pathologies in the resulting fixed point structure and the associated spaces of eigenoperators. We then show how a consistent treatment of the background field through the corresponding modified shift Ward identity, can cure these pathologies, restoring universality of physical quantities with respect to the choice of dependence on the background field, even within the local potential approximation. Along the way we point out similarities to what has been previously found in the f(R) approximation in asymptotic safety for gravity.

  3. Background thermal depolarization of electrons in storage rings

    E-Print Network [OSTI]

    Antonio C. C. Guimaraes; George E. A. Matsas; Daniel A. T. Vanzella

    1997-08-12

    We discuss the influence of the background thermal bath on the depolarization of electrons in high-energy storage rings, and on the photon emission associated with the spin flip. We focus, in particular, on electrons at LEP. We show that in a certain interval of solid angles the photon emission is enhanced several orders of magnitude because of the presence of the thermal bath. Notwithstanding, the overall depolarization induced by the background thermal bath at LEP conditions is much smaller than the one induced by plain acceleration at zero-temperature and can be neglected in practical situations. Eventually we discuss in what conditions the background thermal bath can enhance the overall depolarization by several orders of magnitude.

  4. UK low-background infrastructure for delivering SuperNEMO

    E-Print Network [OSTI]

    Liu, Xin Ran

    2015-01-01

    SuperNEMO is a next generation neutrinoless double beta decay experiment with a design capability to reach a half-life sensitivity of $10^{26}$ years corresponding to an effective Majorana neutrino mass of $\\langle m_{\\beta\\beta} \\rangle$ $<$ 50 - 100 meV. To achieve this sensitivity, stringent radio-purity requirements are imposed resulting in an equally stringent screening programme. Dedicated facilities have been established in the UK for screening and selection of detector construction materials. Gamma ray spectroscopy using high-purity germanium (HPGe) detectors has been the standard method for the measurement of material contamination. A low-background facility has been established at Boulby Underground Laboratory. The first results from the 2 current HPGe detector are shown. Radon is one of the most critical backgrounds for SuperNEMO and most other low background experiments. It can enter the detector either through diffusion, contamination during construction or emanation from the detector material...

  5. Large Scale Cosmic Microwave Background Anisotropies and Dark Energy

    E-Print Network [OSTI]

    J. Weller; A. M. Lewis

    2003-08-29

    In this note we investigate the effects of perturbations in a dark energy component with a constant equation of state on large scale cosmic microwave background anisotropies. The inclusion of perturbations increases the large scale power. We investigate more speculative dark energy models with w<-1 and find the opposite behaviour. Overall the inclusion of perturbations in the dark energy component increases the degeneracies. We generalise the parameterization of the dark energy fluctuations to allow for an arbitrary const ant sound speeds and show how constraints from cosmic microwave background experiments change if this is included. Combining cosmic microwave background with large scale structure, Hubble parameter and Supernovae observations we obtain w=-1.02+-0.16 (1 sigma) as a constraint on the equation of state, which is almost independent of the sound speed chosen. With the presented analysis we find no significant constraint on the constant speed of sound of the dark energy component.

  6. Massive graviton on arbitrary background: derivation, syzygies, applications

    E-Print Network [OSTI]

    Laura Bernard; Cedric Deffayet; Mikael von Strauss

    2015-04-16

    We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our starting point is the de Rham-Gabadadze-Tolley (dRGT) family of ghost free massive gravities and using a simple model of this family, we are able to express this action and these equations of motion in terms of a single metric in which the graviton propagates, hence removing in particular the need for a "reference metric" which is present in the non perturbative formulation. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. This last constraint involves powers and combinations of the curvature of the background metric. The 5 constraints are obtained for a background metric which is unconstrained, i.e. which does not have to obey the background field equations. We then apply these results to the case of Einstein space-times, where we show that the 5 constraints become trivial, and Friedmann-Lema\\^{\\i}tre-Robertson-Walker space-times, for which we correct in particular some results that appeared elsewhere. To reach our results, we derive several non trivial identities, syzygies, involving the graviton fields, its derivatives and the background metric curvature. These identities have their own interest. We also discover that there exist backgrounds for which the dRGT equations cannot be unambiguously linearized.

  7. Radiative emission of neutrino pair free of quantum electrodynamic backgrounds

    E-Print Network [OSTI]

    M. Yoshimura; N. Sasao; M. Tanaka

    2015-01-23

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

  8. 5.0 Management Plan 5.1 Background

    E-Print Network [OSTI]

    of the Blackfoot Subbasin Management Plan consists of a comprehensive set of conservation objectives and strategic218 5.0 Management Plan 5.1 Background The Management Plan is the heart of the Blackfoot Subbasin) strategic actions, 4) research, monitoring and evaluation and 5) consistency with the Endangered Species Act

  9. Computational Science Program Self-Assessment Report 0. Background

    E-Print Network [OSTI]

    Bogaerts, Steven

    1 Computational Science Program Self-Assessment Report July, 2011 0. Background The Director of the Computational Science (COSC) program, Eric Stahlberg, left Wittenberg in late 2010. Since then, Interim Assistant Provost Elizabeth George and a reconstituted Computational Science Advisory Committee (made up

  10. Low Background Radiation Experiment Yields Interesting Preliminary Results

    Office of Energy Efficiency and Renewable Energy (EERE)

    CARLSBAD, N.M., May 18, 2011 – New Mexico State University?s Low Background Radiation Experiment (LBRE), which takes place 2,150 feet below the earth?s surface at the Waste Isolation Pilot Plant, recently released some results about the project?s first two years of experimentation.

  11. Geophysical constraint on a relic background of the dilatons

    E-Print Network [OSTI]

    Sachie Shiomi

    2010-10-15

    According to a scenario in string cosmology, a relic background of light dilatons can be a significant component of the dark matter in the Universe. A new approach of searching for such a dilatonic background by observing Earth's surface gravity was proposed in my previous work. In this paper, the concept of the geophysical search is briefly reviewed, and the geophysical constraint on the dilaton background is presented as a function of the strength of the dilaton coupling, $q_b^2$. For simplicity, I focus on massless dilatons and assume a simple Earth model. With the current upper limit on $q_b^2$, we obtain the upper limit on the dimensionless energy density of the massless background, $\\Omega_{DW}h^2_{100} \\leq 6 \\times 10^{-7}$, which is about one-order of magnitude more stringent than the one from astrophysical observations, at the frequency of $\\sim$ 7 $\\times$ 10$^{-5}$ Hz. If the magnitude of $q_b^2$ is experimentally found to be smaller than the current upper limit by one order of magnitude, the geophysical upper limit on $\\Omega_{DW}h^2_{100}$ becomes less stringent and comparable to the one obtained from the astrophysical observations.

  12. Optimal coherent control of CARS: signal enhancement and background elimination

    E-Print Network [OSTI]

    Fang Gao; Feng Shuang; JunHui Shi; Herschel Rabitz; HaiFeng Wang; JiXin Cheng

    2012-03-28

    The ability to enhance resonant signals and eliminate the non-resonant background is analyzed for Coherent Anti-Stokes Raman Scattering (CARS). The analysis is done at a specific frequency as well as for broadband excitation using femtosecond pulse-shaping techniques. An appropriate objective functional is employed to balance resonant signal enhancement against non-resonant background suppression. Optimal enhancement of the signal and minimization of the background can be achieved by shaping the probe pulse alone while keeping the pump and Stokes pulses in transform-limited-form (TLF). In some cases analytical forms for the probe pulse can be found, and numerical simulations are carried out for other circumstances. It is found that a good approximate solution for the optimal pulse in the two-pulse CARS is a superposition of linear and arctangent type phases for the pump. The well-known probe delay method is shown to be a quasi-optimal scheme for background suppression. The results should provide a basis to improve the performance of CARS spectroscopy and microscopy.

  13. Scalar Radiation in the Background of a Naked Singularity

    E-Print Network [OSTI]

    Anshuman Dey; Pratim Roy; Tapobrata Sarkar

    2013-03-27

    We study scalar radiation spectra from a particle in circular orbit, in the background of the Janis-Newman-Winicour (JNW) naked singularity. The differences in the nature of the spectra, from what one obtains with a Schwarzschild black hole, is established. We also compute the angular distribution of the spectra.

  14. The Isotropic Radio Background and Annihilating Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Belikov, Alexander V.; Jeltema, Tesla E.; Linden, Tim; Profumo, Stefano; Slatyer, Tracy R.

    2012-11-01

    Observations by ARCADE-2 and other telescopes sensitive to low frequency radiation have revealed the presence of an isotropic radio background with a hard spectral index. The intensity of this observed background is found to exceed the flux predicted from astrophysical sources by a factor of approximately 5-6. In this article, we consider the possibility that annihilating dark matter particles provide the primary contribution to the observed isotropic radio background through the emission of synchrotron radiation from electron and positron annihilation products. For reasonable estimates of the magnetic fields present in clusters and galaxies, we find that dark matter could potentially account for the observed radio excess, but only if it annihilates mostly to electrons and/or muons, and only if it possesses a mass in the range of approximately 5-50 GeV. For such models, the annihilation cross section required to normalize the synchrotron signal to the observed excess is sigma v ~ (0.4-30) x 10^-26 cm^3/s, similar to the value predicted for a simple thermal relic (sigma v ~ 3 x 10^-26 cm^3/s). We find that in any scenario in which dark matter annihilations are responsible for the observed excess radio emission, a significant fraction of the isotropic gamma ray background observed by Fermi must result from dark matter as well.

  15. REGION TRACKING WITH NARROW PERCEPTION OF BACKGROUND Julien Mille

    E-Print Network [OSTI]

    Mille, Julien

    address the problem of object tracking within image se- quences through region-based energy minimization. A com- mon underlying assumption in region tracking is that color statistics can be confidently the estima- tion of reliable color statistics for object/background discrim- ination. To overcome

  16. Chiral asymmetry in propagation of soliton defects in crystalline backgrounds

    E-Print Network [OSTI]

    Adrian Arancibia; Mikhail S. Plyushchay

    2015-08-03

    By applying Darboux-Crum transformations to the Lax pair formulation of the Korteweg-de Vries (KdV) equation, we construct new sets of multi-soliton solutions to it as well as to the modified Korteweg-de Vries (mKdV) equation. The obtained solutions exhibit a chiral asymmetry in propagation of different types defects in crystalline backgrounds. We show that the KdV solitons of pulse and compression modulation types, which support bound states in semi-infinite and finite forbidden bands in the spectrum of the perturbed quantum one-gap Lame system, propagate in opposite directions with respect to the asymptotically periodic background. A similar but more complicated picture also appears for the multi-kink-antikink mKdV solitons that propagate with a privileged direction over topologically trivial or topologically nontrivial crystalline background in dependence on position of energy levels of the trapped bound states in spectral gaps of the associated Dirac system. Exotic N=4 nonlinear supersymmetric structure incorporating Lax-Novikov integrals of a pair of perturbed Lame systems is shown to underlie the Miura-Darboux-Crum construction. It unifies the KdV and mKdV solutions, detects the defects and distinguishes their types, and identifies the types of crystalline backgrounds.

  17. BACTERIA-FILTERS: PERSISTENT PARTICLE FILTERS FOR BACKGROUND SUBTRACTION

    E-Print Network [OSTI]

    Peleg, Shmuel

    BACTERIA-FILTERS: PERSISTENT PARTICLE FILTERS FOR BACKGROUND SUBTRACTION Yair Movshovitz switch of bacteria between two states: A normal growing cell and a dormant but persistent cell after the stress is over, bacterial growth continues. Similar to bacteria, particles will switch between

  18. Compressed Gas Cylinder Safety I. Background. Due to the nature

    E-Print Network [OSTI]

    Zhang, Zhongfei "Mark"

    Compressed Gas Cylinder Safety I. Background. Due to the nature of gas cylinders hazards of a ruptured cylinder. There are almost 200 different types of materials in gas cylinders, there are several general procedures to follow for safe storage and handling of a compressed gas cylinder: II

  19. Observation of objects under intense plasma background illumination

    SciTech Connect (OSTI)

    Buzhinsky, R. O.; Savransky, V. V.; Zemskov, K. I.; Isaev, A. A.; Buzhinsky, O. I.

    2010-12-15

    Experiments on the observation of a brightness-amplified image of an object through a masking arc discharge are presented. The copper-vapor laser active medium was used as an image brightness amplifier. It is shown that the image quality does not worsen under plasma background illumination.

  20. COBE Diffuse Infrared Background Experiment (DIRBE ) Explanatory Supplement

    E-Print Network [OSTI]

    Siebenmorgen, Ralf

    COBE Diffuse Infrared Background Experiment (DIRBE ) Explanatory Supplement edited by M. G. Hauser Supplement that describes the DIRBE data products, most of Chapter 4 (Data Processing and Instrument Characterization) was omitted from the present version. The complete Explanatory Supplement will be released

  1. Issue Backgrounder : Downstream Fish Migration : Improving the Odds of Survival.

    SciTech Connect (OSTI)

    United States. Bonneville Power Administration.

    1985-05-01

    Background information is given on the problems caused to anadromous fish migrations, especially salmon and steelhead trout, by the development of hydroelectric power dams on the Columbia River and its tributaries. Programs arising out of the Pacific Northwest Electric Power Planning and conservation Act of 1980 to remedy these problems and restore fish and wildlife populations are described. (ACR)

  2. Efficient Cosmological Parameter Estimation from Microwave Background Anisotropies

    E-Print Network [OSTI]

    Arthur Kosowsky; Milos Milosavljevic; Raul Jimenez

    2002-06-02

    We revisit the issue of cosmological parameter estimation in light of current and upcoming high-precision measurements of the cosmic microwave background power spectrum. Physical quantities which determine the power spectrum are reviewed, and their connection to familiar cosmological parameters is explicated. We present a set of physical parameters, analytic functions of the usual cosmological parameters, upon which the microwave background power spectrum depends linearly (or with some other simple dependence) over a wide range of parameter values. With such a set of parameters, microwave background power spectra can be estimated with high accuracy and negligible computational effort, vastly increasing the efficiency of cosmological parameter error determination. The techniques presented here allow calculation of microwave background power spectra $10^5$ times faster than comparably accurate direct codes (after precomputing a handful of power spectra). We discuss various issues of parameter estimation, including parameter degeneracies, numerical precision, mapping between physical and cosmological parameters, and systematic errors, and illustrate these considerations with an idealized model of the MAP experiment.

  3. Chemical and Biological Engineering Model Predictive Control: Background

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    == - - = -- --- = DC C V F CC B k V F k Ckk V F A Bs s AsAfs s As s = f1 = f2 etcCAux Asss C f x f A , 1 ,1 1 11Chemical and Biological Engineering Model Predictive Control: Background B. Wayne Bequette "windup" problems Does not explicitly require a process model #12;Chemical and Biological Engineering

  4. HsO Travel/Conference Fee Award Background

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    HsO Travel/Conference Fee Award Background: The main purpose of the Hatfield Students Organization to present their research findings at professional conferences related to their field of study. To support student participation in such conferences, HsO, has created an annual award of $250 to help finance

  5. TESTING INFLATION WITH THE COSMIC BACKGROUND J. Richard BOND

    E-Print Network [OSTI]

    Bond, Dick

    (1994);Proc. 8th Nishinomiya-YukawaMemorial Symposium, Japan, October 1993 1 #12;2 1. Introduction noise generated during acceleration is a natural byproduct that may account for the observed structure geometry. For a at background of most relevance to in ation models, it is simply a plane wave, Qk

  6. Background resistivity model from seismic velocities Dieter Werthmller1

    E-Print Network [OSTI]

    are conductive, for in- stance, brine, or resistive, for instance, hydrocarbons. Geophysicists process seismic of aligning seismic arrivals. This process of deriving a geophysical property directly from the dataBackground resistivity model from seismic velocities Dieter Werthmüller1 , Anton Ziolkowski1

  7. PART I. INTRODUCTION AND BACKGROUND: PHYSICS EDUCATION RESEARCH,

    E-Print Network [OSTI]

    Maryland at College Park, University of

    1 PART I. INTRODUCTION AND BACKGROUND: PHYSICS EDUCATION RESEARCH, STUDENT LEARNING AND ASSESSMENT Chapter 1. Introduction Physics Education Research (PER) has led to the development of a large number Workshop Physics.3 I. MOTIVATION Over the last twenty years, PER has changed our view of student learning

  8. Integrating a discrete motion model into GMM based background subtraction

    E-Print Network [OSTI]

    Wolf, Christian

    consecutive frames minimizing a global energy function taking into account spatial and temporal re- lationships. A discrete approximative optical-flow like motion model is integrated into the energy function, for instance for track- ing algorithms. Most existing methods build an explicit background model either using

  9. II. HISTORICAL BACKGROUND Since 1977 the University of Oregon Solar

    E-Print Network [OSTI]

    Oregon, University of

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

  10. An array of low-background 3 He proportional counters

    E-Print Network [OSTI]

    An array of low-background 3 He proportional counters for the Sudbury Neutrino Observatory J. F-current sensitivity of the SNO detector. This array consisted of 36 strings of proportional counters filled measurements. The proportional counter diameter is 5 cm. The total deployed array length was 398 m. The SNO NCD

  11. El Nino -Southern Oscillations: Phenomenology and dynamical background Eli Tziperman

    E-Print Network [OSTI]

    Tziperman, Eli

    Lecture 1 El Nino - Southern Oscillations: Phenomenology and dynamical background Eli Tziperman 1 and animations are available on the El Nino theme page at http://www.pmel.noaa.gov/tao/elnino/nino- home anomalies during La Nina, normal conditions and during El Nino are shown in Fig. 15. The slope

  12. Cosmic and Galactic Neutrino Backgrounds from Thermonuclear Sources

    E-Print Network [OSTI]

    Cristiano Porciani; Silvia Petroni; Giovanni Fiorentini

    2003-11-20

    We estimate energy spectra and fluxes at the Earth's surface of the cosmic and Galactic neutrino backgrounds produced by thermonuclear reactions in stars. The extra-galactic component is obtained by combining the most recent estimates of the cosmic star formation history and the stellar initial mass function with accurate theoretical predictions of the neutrino yields all over the thermonuclear lifetime of stars of different masses. Models of the structure and evolution of the Milky Way are used to derive maps of the expected flux generated by Galactic sources as a function of sky direction. The predicted neutrino backgrounds depend only slightly on model parameters. In the relevant 50 keV-10 MeV window, the total flux of cosmic neutrinos ranges between 20 and 65 particles per square cm per s. Neutrinos reaching the Earth today have been typically emitted at redshift z~2. Their energy spectrum peaks at E~0.1-0.3 MeV. The energy and entropy densities of the cosmic background are negligible with respect to the thermal contribution of relic neutrinos originated in the early universe. In every sky direction, the cosmic background is outnumbered by the Galactic one, whose integrated flux amounts to 300-1000 particles per square cm per s. The emission from stars in the Galactic disk contributes more than 95 per cent of the signal.

  13. Ecosystem engineering by beavers affects mayfly life MATTHEW R. FULLER*, ,

    E-Print Network [OSTI]

    McIntosh, Angus

    colder downstream of high-head dams and warmer downstream of low-head dams. Pond morphology was also), with larger females emerging downstream of high- head dams and smaller females downstream of low-head dams

  14. Beaver City Corporation (Utility Company) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar Energy LLC Jump to:Greece:Bajo en Carbono,BeWind Power LtdBean CommercialCity

  15. Beaver County, Oklahoma: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAE

  16. Beaver County, Pennsylvania: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAEInformation

  17. Beaver County, Utah: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAEInformationUtah

  18. Beaver Cove, Maine: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAEInformationUtahCove,

  19. Beaver Creek, Minnesota: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina

  20. City of Beaver City, Nebraska (Utility Company) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButte County,Camilla,Thermal GradientChateauChoosEV JumpAnita, IowaCity ofCity

  1. Simulation of natural radioactivity backgrounds in the central detector

    E-Print Network [OSTI]

    Xinying Li; Ziyan Deng; Liangjian Wen; Weidong Li; Zhengyun You; Chunxu Yu; Yumei Zhang; Tao Lin

    2015-05-13

    The Jiangmen Underground Neutrino Observatory (JUNO) is an experiment proposed to determine the neutrino mass hierarchy and probe the fundamental properties of neutrino oscillation. The JUNO central detector is a spherical liquid scintillator detector with 20 kton fiducial mass. It is required to achieve a $3\\%/\\sqrt{E(MeV)}$ energy resolution with very low radioactive background, which is a big challenge to the detector design. In order to ensure the detector performance can meet the physics requirements, reliable detector simulation is necessary to provide useful information for detector design. A simulation study of natural radioactivity backgrounds in the JUNO central detector has been performed to guide the detector design and set requirements to the radiopurity of detector materials.

  2. Virasoro Conformal Blocks and Thermality from Classical Background Fields

    E-Print Network [OSTI]

    A. Liam Fitzpatrick; Jared Kaplan; Matthew T. Walters

    2015-10-15

    We show that in 2d CFTs at large central charge, the coupling of the stress tensor to heavy operators can be re-absorbed by placing the CFT in a non-trivial background metric. This leads to a more precise computation of the Virasoro conformal blocks between heavy and light operators, which are shown to be equivalent to global conformal blocks evaluated in the new background. We also generalize to the case where the operators carry U(1) charges. The refined Virasoro blocks can be used as the seed for a new Virasoro block recursion relation expanded in the heavy-light limit. We comment on the implications of our results for the universality of black hole thermality in $AdS_3$, or equivalently, the eigenstate thermalization hypothesis for $CFT_2$ at large central charge.

  3. What are the galaxies contributing to the Cosmic Infrared Background ?

    E-Print Network [OSTI]

    B. Guiderdoni

    1997-12-29

    Recent optical observations have led to a significant progress in our understanding of galaxy formation and evolution. However, our view on the deep universe is currently limited to the starlight which directly escapes from high-redshift galaxies, since we so far ignore the fraction of luminosity absorbed by dust and released in the IR/submm wavelength range. A new constraint is set by the possible detection of the Cosmic Infrared Background. We briefly review the observations and use a semi-analytic model of galaxy formation and evolution to predict number counts consistent with the level of the background. It turns out that the predictions fairly accomodate preliminary data at 175 and 850 microns. This suggests that a significant fraction of star/galaxy formation at high z is hidden by dust.

  4. Radon induced surface contaminations in low background experiments

    SciTech Connect (OSTI)

    Pattavina, L. [INFN - Laboratori Nazionali del Gran Sasso, I-67010 Assergi (AQ) (Italy)] [INFN - Laboratori Nazionali del Gran Sasso, I-67010 Assergi (AQ) (Italy)

    2013-08-08

    In neutrinoless double-beta decay and dark matter searches, one of the main issues is to increase the experimental sensitivity through careful material selection and production, minimizing the background contributions. In order to achieve the required, extremely low, counting rates, very stringent requirements must be fulfilled in terms of bulk material radiopurity. As the experimental sensitivity increases, the bulk impurities in the detector components decrease, and surface contaminations start to play an increasingly significant role In fully active detectors, like cryogenic particle detectors, surface contaminations are a critical issue (as shown by the CUORICINO experiment). {sup 222}Rn is by far the most intense source of airborne radioactivity, and if a radio-pure material is exposed to environment where the Radon concentration is not minimized, {sup 210}Pb and {sup 210}Po contaminations can occur. The mechanisms and the dynamics of Radon-induced surface contaminations are reviewed, and specific solutions to prevent and to reject the induced background are presented.

  5. Five-dimensional Gauge Theories in a warped background

    E-Print Network [OSTI]

    Richard D. Kenway; Eliana Lambrou

    2015-10-26

    The phase diagram of five-dimensional anisotropic gauge theories in a flat background has been extensively explored during the last decade. Here, we present novel results for the phase structure of the five-dimensional anisotropic SU(2) model embedded in a warped background. The static potential in the deconfining region of the phase diagram, close to the transition to the layered phase, provides evidence of a Yukawa mass, suggesting that the system is in a 4D Higgs-like phase. As no symmetry has been broken by the boundary conditions, this phase appears to be due to the warp factor. Whether the system is dimensionally reduced from a 5D phase to this 4D Higgs-like phase, which would provide a mechanism for dimensional reduction via localization, remains open.

  6. Statistical Mechanics of gravitating systems in static and cosmological backgrounds

    E-Print Network [OSTI]

    T. Padmanabhan

    2002-06-09

    This pedagogical review addresses several issues related to statistical description of gravitating systems in both static and expanding backgrounds, focusing on the latter. After briefly reviewing the results for the static background, I describe the key issues and recent progress in the context of gravitational clustering of collision-less particles in an expanding universe. The questions addressed include: (a) How does the power injected into the system at a given wave number spread to smaller and larger scales? (b) How does the power spectrum of density fluctuations behave asymptotically at late times? (c) What are the universal characteristics of gravitational clustering that are independent of the initial conditions and manifest at the late time evolution of the system? The review is intended for non cosmologists and will be of interest to people working in fluid mechanics, non linear dynamics and condensed matter physics.

  7. Background Oriented Schlieren in a Density Stratified Fluid

    E-Print Network [OSTI]

    Verso, Lilly

    2015-01-01

    Non-intrusive quantitative fluid density measurements methods are essential in stratified flow experiments. Digital imaging leads to synthetic Schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an important extension to one of these methods, called Background Oriented Schlieren (BOS), is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multi-media imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide non-intrusive full-field density measurements of transparent liquids.

  8. Higgs effective potential in a perturbed Robertson-Walker background

    E-Print Network [OSTI]

    Antonio L. Maroto; Francisco Prada

    2014-12-15

    We calculate the one-loop effective potential of a scalar field in a Robertson-Walker background with scalar metric perturbations. A complete set of orthonormal solutions of the perturbed equations is obtained by using the adiabatic approximation for comoving observers. After analyzing the problem of renormalization in inhomogeneous backgrounds, we get the explicit contribution of metric perturbations to the effective potential. We apply these results to the Standard Model Higgs field and evaluate the effects of metric perturbations on the Higgs mass and on its vacuum expectation value. Space-time variations are found, which are proportional to the gravitational slip parameter, with a typical amplitude of the order of $\\Delta\\phi/\\phi\\simeq 10^{-11}$ on cosmological scales. We also discuss possible astrophysical signatures in the Solar System and in the Milky Way that could open new possibilities to explore the symmetry breaking sector of the electroweak interactions.

  9. RESOLVING THE RADIO SOURCE BACKGROUND: DEEPER UNDERSTANDING THROUGH CONFUSION

    SciTech Connect (OSTI)

    Condon, J. J.; Cotton, W. D.; Fomalont, E. B.; Kellermann, K. I.; Miller, N.; Perley, R. A.; Scott, D.; Vernstrom, T.; Wall, J. V.

    2012-10-10

    We used the Karl G. Jansky Very Large Array to image one primary beam area at 3 GHz with 8'' FWHM resolution and 1.0 {mu}Jy beam{sup -1} rms noise near the pointing center. The P(D) distribution from the central 10 arcmin of this confusion-limited image constrains the count of discrete sources in the 1 < S({mu}Jy) < 10 range. At this level, the brightness-weighted differential count S {sup 2} n(S) is converging rapidly, as predicted by evolutionary models in which the faintest radio sources are star-forming galaxies; and Almost-Equal-To 96% of the background originating in galaxies has been resolved into discrete sources. About 63% of the radio background is produced by active galactic nuclei (AGNs), and the remaining 37% comes from star-forming galaxies that obey the far-infrared (FIR)/radio correlation and account for most of the FIR background at {lambda} Almost-Equal-To 160 {mu}m. Our new data confirm that radio sources powered by AGNs and star formation evolve at about the same rate, a result consistent with AGN feedback and the rough correlation of black hole and stellar masses. The confusion at centimeter wavelengths is low enough that neither the planned Square Kilometre Array nor its pathfinder ASKAP EMU survey should be confusion limited, and the ultimate source detection limit imposed by 'natural' confusion is {<=}0.01 {mu}Jy at {nu} = 1.4 GHz. If discrete sources dominate the bright extragalactic background reported by ARCADE 2 at 3.3 GHz, they cannot be located in or near galaxies and most are {<=}0.03 {mu}Jy at 1.4 GHz.

  10. An Ultra-Low Background PMT for Liquid Xenon Detectors

    E-Print Network [OSTI]

    D. S. Akerib; X. Bai; E. Bernard; A. Bernstein; A. Bradley; D. Byram; S. B. Cahn; M. C. Carmona-Benitez; D. Carr; J. J. Chapman; Y-D. Chan; K. Clark; T. Coffey; L. deViveiros; M. Dragowsky; E. Druszkiewicz; B. Edwards; C. H. Faham; S. Fiorucci; R. J. Gaitskell; K. R. Gibson; C. Hall; M. Hanhardt; B. Holbrook; M. Ihm; R. G. Jacobsen; L. Kastens; K. Kazkaz; N. Larsen; C. Lee; K. Lesko; A. Lindote; M. I. Lopes; A. Lyashenko; D. C. Malling; R. Mannino; D. McKinsey; D. Mei; J. Mock; M. Morii; H. Nelson; F. Neves; J. A. Nikkel; M. Pangilinan; K. Pech; P. Phelps; T. Shutt; C. Silva; W. Skulski; V. N. Solovov; P. Sorensen; J. Spaans; T. Stiegler; M. Sweany; M. Szydagis; D. Taylor; J. Thomson; M. Tripathi; S. Uvarov; J. R. Verbus; N. Walsh; R. Webb; J. T. White; M. Wlasenko; F. L. H. Wolfs; M. Woods; C. Zhang

    2013-06-24

    Results are presented from radioactivity screening of two models of photomultiplier tubes designed for use in current and future liquid xenon experiments. The Hamamatsu 5.6 cm diameter R8778 PMT, used in the LUX dark matter experiment, has yielded a positive detection of four common radioactive isotopes: 238U, 232Th, 40K, and 60Co. Screening of LUX materials has rendered backgrounds from other detector materials subdominant to the R8778 contribution. A prototype Hamamatsu 7.6 cm diameter R11410 MOD PMT has also been screened, with benchmark isotope counts measured at <0.4 238U / <0.3 232Th / <8.3 40K / 2.0+-0.2 60Co mBq/PMT. This represents a large reduction, equal to a change of \\times 1/24 238U / \\times 1/9 232Th / \\times 1/8 40K per PMT, between R8778 and R11410 MOD, concurrent with a doubling of the photocathode surface area (4.5 cm to 6.4 cm diameter). 60Co measurements are comparable between the PMTs, but can be significantly reduced in future R11410 MOD units through further material selection. Assuming PMT activity equal to the measured 90% upper limits, Monte Carlo estimates indicate that replacement of R8778 PMTs with R11410 MOD PMTs will change LUX PMT electron recoil background contributions by a factor of \\times1/25 after further material selection for 60Co reduction, and nuclear recoil backgrounds by a factor of \\times 1/36. The strong reduction in backgrounds below the measured R8778 levels makes the R11410 MOD a very competitive technology for use in large-scale liquid xenon detectors.

  11. Apparatus for eliminating background interference in fluorescence measurements

    DOE Patents [OSTI]

    Martin, J.C.; Jett, J.H.

    1986-03-04

    The disclosure is directed to an apparatus for eliminating background interference during fluorescence measurements in a multiple laser flow cytometer. A biological particle stained with fluorescent dyes is excited by a laser. A fluorescence detector detects the fluorescence. The particle scatters light and a gate signal is generated and delayed until the biological particle reaches the next laser. The delayed signal turns on this next laser, which excites a different stained component of the same biological particle. 8 figs.

  12. Constraining fundamental physics with the cosmic microwave background

    E-Print Network [OSTI]

    Anthony Challinor

    2006-06-22

    The temperature anisotropies and polarization of the cosmic microwave background (CMB) radiation provide a window back to the physics of the early universe. They encode the nature of the initial fluctuations and so can reveal much about the physical mechanism that led to their generation. In this contribution we review what we have learnt so far about early-universe physics from CMB observations, and what we hope to learn with a new generation of high-sensitivity, polarization-capable instruments.

  13. Comments on Superstring Interactions in a Plane-Wave Background

    E-Print Network [OSTI]

    John H. Schwarz

    2002-09-03

    The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background is investigated. Specifically, we derive a factorization theorem for the Neumann coefficients that generalizes a flat-space result that was obtained some 20 years ago. The resulting formula is used to explore the leading large mu asymptotic behavior, which is relevant for comparison with dual gauge theory results.

  14. Upper limit map of a background of gravitational waves

    E-Print Network [OSTI]

    Abbott, B; Adhikari, R; Agresti, J; Ajith, P; Allen, B; Amin, R; Anderson, S B; Anderson, W G; Arain, M; Araya, M; Armandula, H; Ashley, M; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bayer, K; Belczynski, K; Betzwieser, J; Beyersdorf, P T; Bhawal, B; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bogenstahl, J; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A; Brown, D A; Bullington, A; Bunkowski, A; Buonanno, A; Burmeister, O; Busby, D; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cantley, C A; Cao, J; Cardenas, L; Casey, M M; Castaldi, G; Cepeda, C; Chalkey, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Chiadini, F; Chin, D; Chin, E; Chow, J; Christensen, N; Clark, J; Cochrane, P; Cokelaer, T; Colacino, C N; Coldwell, R; Conte, R; Cook, D; Corbitt, T; Coward, D; Coyne, D; Creighton, J D E; Creighton, T D; Croce, R P; Crooks, D R M; Cruise, A M; Cumming, A; Dalrymple, J; D'Ambrosio, E; Danzmann, K; Davies, G; De Bra, D; Degallaix, J; Degree, M; Demma, T; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S V; Díaz, M; Dickson, J; Di Credico, A; Diederichs, G; Dietz, A; Doomes, E E; Drever, R W P; Dumas, J C; Dupuis, R J; Dwyer, J G; Ehrens, P; Espinoza, E; Etzel, T; Evans, M; Evans, T; Fairhurst, S; Fan, Y; Fazi, D; Fejer, M M; Finn, L S; Fiumara, V; Fotopoulos, N; Franzen, A; Franzen, K Y; Freise, A; Frey, R; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Galdi, V; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L; González, G; Gossler, S; Grant, A; Gras, S; Gray, C; Gray, M; Greenhalgh, J; Gretarsson, A M; Grosso, R; Grote, H; Grünewald, S; Günther, M; Gustafson, R; Hage, B; Hammer, D; Hanna, C; Hanson, J; Harms, J; Harry, G; Harstad, E; Hayler, T; Heefner, J; Heng, I S; Heptonstall, A; Heurs, M; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Hosken, D; Hough, J; Howell, E; Hoyland, D; Huttner, S H; Ingram, D; Innerhofer, E; Ito, M; Itoh, Y; Ivanov, A; Jackrel, D; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalili, F Ya; Kim, C; King, P; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R K; Kozak, D; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lantz, B; Lazzarini, A; Lee, B; Lei, M; Leiner, J; Leonhardt, V; Leonor, I; Libbrecht, K; Lindquist, P; Lockerbie, N A; Longo, M; Lormand, M; Lubinski, M; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Malec, M; Mandic, V; Marano, S; Marka, S; Markowitz, J; Maros, E; Martin, I; Marx, J N; Mason, K; Matone, L; Matta, V; Mavalvala, N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McKenzie, K; McNabb, J W C; McWilliams, S; Meier, T; Melissinos, A C; Mendell, G; Mercer, R A; Meshkov, S; Messaritaki, E; Messenger, C J; Meyers, D; Mikhailov, E; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Moylan, A; Mudge, D; Müller, G; Mukherjee, S; Muller-Ebhardt, H; Munch, J; Murray, P; Myers, E; Myers, J; Newton, G; Nishizawa, A; Numata, K; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Overmier, H; Owen, B J; Pan, Y; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Pierro, V; Pinto, I M; Pitkin, M; Pletsch, H; Plissi, M V; Postiglione, F; Prix, R; Quetschke, V; Raab, F; Rabeling, D; Radkins, H; Rahkola, R; Rainer, N; Rakhmanov, M; Ray-Majumder, S; Re, V; Rehbein, H; Reid, S; Reitze, D H; Ribichini, L; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rodríguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sancho de la Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Schediwy, S; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Shoemaker, D H; Sibley, A; Sidles, J A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B; Slutsky, J; Smith, J R; Smith, M R; Somiya, K; Strain, K A; Strom, D M; Stuver, A; Summerscales, T Z; Sun, K X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Tarallo, M; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D W; Ungarelli, C; Urbanek, K; Vahlbruch, H; Vallisneri, M; Van Den Broeck, C; Varvella, M; Vass, S; Vecchio, A; Veitch, J; Veitch, P; Villar, A; Vorvick, C; Vyachanin, S P; Waldman, S J; Wallace, L

    2007-01-01

    We searched for an anisotropic background of gravitational waves using data from the LIGO S4 science run and a method that is optimized for point sources. This is appropriate if, for example, the gravitational wave background is dominated by a small number of distinct astrophysical sources. No signal was seen. Upper limit maps were produced assuming two different power laws for the source strain power spectrum. For an f^-3 power law and using the 50 Hz to 1.8 kHz band the upper limits on the source strain power spectrum vary between 1.2e-48 Hz^-1 (100 Hz/f)^3 and 1.2e-47 Hz^-1 (100 Hz /f)^3, depending on the position in the sky. Similarly, in the case of constant strain power spectrum, the upper limits vary between 8.5e-49 Hz^-1 and 6.1e-48 Hz^-1. As a side product a limit on an isotropic background of gravitational waves was also obtained. All limits are at the 90% confidence level. Finally, as an application, we focused on the direction of Sco-X1, the closest low-mass X-ray binary. We compare the upper limi...

  15. Tagging Spallation Backgrounds with Showers in Water-Cherenkov Detectors

    E-Print Network [OSTI]

    Li, Shirley Weishi

    2015-01-01

    Cosmic-ray muons and especially their secondaries break apart nuclei ("spallation") and produce fast neutrons and beta-decay isotopes, which are backgrounds for low-energy experiments. In Super-Kamiokande, these beta decays are the dominant background in 6--18 MeV, relevant for solar neutrinos and the diffuse supernova neutrino background. In a previous paper, we showed that these spallation isotopes are produced primarily in showers, instead of in isolation. This explains an empirical spatial correlation between a peak in the muon Cherenkov light profile and the spallation decay, which Super-Kamiokande used to develop a new spallation cut. However, the muon light profiles that Super-Kamiokande measured are grossly inconsistent with shower physics. We show how to resolve this discrepancy and how to reconstruct accurate profiles of muons and their showers from their Cherenkov light. We propose a new spallation cut based on these improved profiles and quantify its effects. Our results can significantly benefit ...

  16. Radon induced background processes in the KATRIN pre-spectrometer

    E-Print Network [OSTI]

    Fränkle, F M; Drexlin, G; Glück, F; Görhardt, S; Käfer, W; Mertens, S; Wandkowsky, N; Wolf, J

    2011-01-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale tritium beta-decay experiment to determine the effective electron anti-neutrino mass by investigating the kinematics of tritium beta-decay with a sensitivity of 200 meV/c2 using the MAC-E filter technique. In order to reach this sensitivity, a low background level of 0.01 counts per second (cps) is required. This paper describes how the decay of radon in a MAC-E filter generates background events, based on measurements performed at the KATRIN pre-spectrometer test setup. Radon (Rn) atoms, which emanate from materials inside the vacuum region of the KATRIN spectrometers, are able to penetrate deep into the magnetic flux tube so that the alpha-decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha-decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. While low-energy electrons (<...

  17. Chiral asymmetry in propagation of soliton defects in crystalline backgrounds

    E-Print Network [OSTI]

    Arancibia, Adrian

    2015-01-01

    By applying Darboux-Crum transformations to the Lax pair formulation of the Korteweg-de Vries (KdV) equation, we construct new sets of multi-soliton solutions to it as well as to the modified Korteweg-de Vries (mKdV) equation. The obtained solutions exhibit a chiral asymmetry in propagation of different types defects in crystalline backgrounds. We show that the KdV solitons of pulse and compression modulation types, which support bound states in semi-infinite and finite forbidden bands in the spectrum of the perturbed quantum one-gap Lame system, propagate in opposite directions with respect to the asymptotically periodic background. A similar but more complicated picture also appears for the multi-kink-antikink mKdV solitons that propagate with a privileged direction over topologically trivial or topologically nontrivial crystalline background in dependence on position of energy levels of the trapped bound states in spectral gaps of the associated Dirac system. Exotic N=4 nonlinear supersymmetric structure i...

  18. Low-background tracker development for SuperNEMO

    SciTech Connect (OSTI)

    Mott, James [University College London, London, WC1E 6BT (United Kingdom)] [University College London, London, WC1E 6BT (United Kingdom); Collaboration: SuperNEMO Collaboration; and others

    2013-08-08

    The SuperNEMO experiment will search for neutrinoless double beta decay (0???) with a target sensitivity of T{sub 1/2}(0?) > 10{sup 26} years, corresponding to an effective neutrino mass of 50-100 meV. At its heart there is a low-background gaseous tracking detector which allows for extremely efficient background rejection and, if 0??? is observed, may provide important insights into the mechanism via which it may be mediated. Radon inside the tracker, which can mimic rare ?? events, is one of the most dangerous backgrounds for SuperNEMO. To reach the target sensitivity the radon concentration inside the tracking volume must be < 0.15 mBq/m{sup 3}. To reach this challengingly-low level of radon, a considerable program of R and D has been undertaken. This includes automation of the tracker-wiring process, development of a dedicated setup to measure radon diffusion and a 'radon concentration line' which will be able to measure levels of radon in the ?Bq/m{sup 3} range.

  19. Design Considerations for Large Mass Ultra-Low Background Experiments

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E.; Orrell, John L.

    2011-07-01

    Summary The objective of this document is to present the designers of the next generation of large-mass, ultra-low background experiments with lessons learned and design strategies from previous experimental work. Design issues divided by topic into mechanical, thermal and electrical requirements are addressed. Large mass low-background experiments have been recognized by the scientific community as appropriate tools to aid in the refinement of the standard model. The design of these experiments is very costly and a rigorous engineering review is required for their success. The extreme conditions that the components of the experiment must withstand (heavy shielding, vacuum/pressure and temperature gradients), in combination with unprecedented noise levels, necessitate engineering guidance to support quality construction and safe operating conditions. Physical properties and analytical results of typical construction materials are presented. Design considerations for achieving ultra-low-noise data acquisition systems are addressed. Five large-mass, low-background conceptual designs for the one-tonne scale germanium experiment are proposed and analyzed. The result is a series of recommendations for future experiments engineering and for the Majorana simulation task group to evaluate the different design approaches.

  20. Tagging Spallation Backgrounds with Showers in Water-Cherenkov Detectors

    E-Print Network [OSTI]

    Shirley Weishi Li; John F. Beacom

    2015-08-21

    Cosmic-ray muons and especially their secondaries break apart nuclei ("spallation") and produce fast neutrons and beta-decay isotopes, which are backgrounds for low-energy experiments. In Super-Kamiokande, these beta decays are the dominant background in 6--18 MeV, relevant for solar neutrinos and the diffuse supernova neutrino background. In a previous paper, we showed that these spallation isotopes are produced primarily in showers, instead of in isolation. This explains an empirical spatial correlation between a peak in the muon Cherenkov light profile and the spallation decay, which Super-Kamiokande used to develop a new spallation cut. However, the muon light profiles that Super-Kamiokande measured are grossly inconsistent with shower physics. We show how to resolve this discrepancy and how to reconstruct accurate profiles of muons and their showers from their Cherenkov light. We propose a new spallation cut based on these improved profiles and quantify its effects. Our results can significantly benefit low-energy studies in Super-Kamiokande, and will be especially important for detectors at shallower depths, like the proposed Hyper-Kamiokande.

  1. Astrometric Effects of a Stochastic Gravitational Wave Background

    E-Print Network [OSTI]

    Laura G. Book; Éanna É. Flanagan

    2012-11-27

    A stochastic gravitational wave background causes the apparent positions of distant sources to fluctuate, with angular deflections of order the characteristic strain amplitude of the gravitational waves. These fluctuations may be detectable with high precision astrometry, as first suggested by Braginsky et al. in 1990. Several researchers have made order of magnitude estimates of the upper limits obtainable on the gravitational wave spectrum \\Omega_gw(f), at frequencies of order f ~ 1 yr^-1, both for the future space-based optical interferometry missions GAIA and SIM, and for VLBI interferometry in radio wavelengths with the SKA. For GAIA, tracking N ~ 10^6 quasars over a time of T ~ 1 yr with an angular accuracy of \\Delta \\theta ~ 10 \\mu as would yield a sensitivity level of \\Omega_gw ~ (\\Delta \\theta)^2/(N T^2 H_0^2) ~ 10^-6, which would be comparable with pulsar timing. In this paper we take a first step toward firming up these estimates by computing in detail the statistical properties of the angular deflections caused by a stochastic background. We compute analytically the two point correlation function of the deflections on the sphere, and the spectrum as a function of frequency and angular scale. The fluctuations are concentrated at low frequencies (for a scale invariant stochastic background), and at large angular scales, starting with the quadrupole. The magnetic-type and electric-type pieces of the fluctuations have equal amounts of power.

  2. Real-Time Active Cosmic Neutron Background Reduction Methods

    SciTech Connect (OSTI)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Mitchell, Stephen; Guss, Paul

    2013-09-01

    Neutron counting using large arrays of pressurized 3He proportional counters from an aerial system or in a maritime environment suffers from the background counts from the primary cosmic neutrons and secondary neutrons caused by cosmic ray?induced mechanisms like spallation and charge-exchange reaction. This paper reports the work performed at the Remote Sensing Laboratory–Andrews (RSL-A) and results obtained when using two different methods to reduce the cosmic neutron background in real time. Both methods used shielding materials with a high concentration (up to 30% by weight) of neutron-absorbing materials, such as natural boron, to remove the low-energy neutron flux from the cosmic background as the first step of the background reduction process. Our first method was to design, prototype, and test an up-looking plastic scintillator (BC-400, manufactured by Saint Gobain Corporation) to tag the cosmic neutrons and then create a logic pulse of a fixed time duration (~120 ?s) to block the data taken by the neutron counter (pressurized 3He tubes running in a proportional counter mode). The second method examined the time correlation between the arrival of two successive neutron signals to the counting array and calculated the excess of variance (Feynman variance Y2F)1 in the neutron count distribution from Poisson distribution. The dilution of this variance from cosmic background values ideally would signal the presence of man-made neutrons.2 The first method has been technically successful in tagging the neutrons in the cosmic-ray flux and preventing them from being counted in the 3He tube array by electronic veto—field measurement work shows the efficiency of the electronic veto counter to be about 87%. The second method has successfully derived an empirical relationship between the percentile non-cosmic component in a neutron flux and the Y2F of the measured neutron count distribution. By using shielding materials alone, approximately 55% of the neutron flux from man-made sources like 252Cf or Am-Be was removed.

  3. pn-CCDs in a Low-Background Environment: Detector Background of the CAST X-ray Telescope

    E-Print Network [OSTI]

    M. Kuster; S. Cebrian; A. Rodriquez; R. Kotthaus; H. Braeuninger; J. Franz; P. Friedrich; R. Hartmann; D. Kang; G. Lutz; L. Strueder

    2005-08-10

    The CAST experiment at CERN (European Organization of Nuclear Research) searches for axions from the sun. The axion is a pseudoscalar particle that was motivated by theory thirty years ago, with the intention to solve the strong CP problem. Together with the neutralino, the axion is one of the most promising dark matter candidates. The CAST experiment has been taking data during the last two years, setting an upper limit on the coupling of axions to photons more restrictive than from any other solar axion search in the mass range below 0.1 eV. In 2005 CAST will enter a new experimental phase extending the sensitivity of the experiment to higher axion masses. The CAST experiment strongly profits from technology developed for high energy physics and for X-ray astronomy: A superconducting prototype LHC magnet is used to convert potential axions to detectable X-rays in the 1-10 keV range via the inverse Primakoff effect. The most sensitive detector system of CAST is a spin-off from space technology, a Wolter I type X-ray optics in combination with a prototype pn-CCD developed for ESA's XMM-Newton mission. As in other rare event searches, background suppression and a thorough shielding concept is essential to improve the sensitivity of the experiment to the best possible. In this context CAST offers the opportunity to study the background of pn-CCDs and its long term behavior in a terrestrial environment with possible implications for future space applications. We will present a systematic study of the detector background of the pn-CCD of CAST based on the data acquired since 2002 including preliminary results of our background simulations.

  4. Muon-Induced Background Study for Underground Laboratories

    E-Print Network [OSTI]

    D. -M. Mei; A. Hime

    2005-12-06

    We provide a comprehensive study of the cosmic-ray muon flux and induced activity as a function of overburden along with a convenient parameterization of the salient fluxes and differential distributions for a suite of underground laboratories ranging in depth from $\\sim$1 to 8 km.w.e.. Particular attention is given to the muon-induced fast neutron activity for the underground sites and we develop a Depth-Sensitivity-Relation to characterize the effect of such background in experiments searching for WIMP dark matter and neutrinoless double beta decay.

  5. Compactification on the ?-background and the AGT correspondence

    E-Print Network [OSTI]

    Junya Yagi

    2013-05-07

    The six-dimensional (2,0) theory formulated in the \\Omega-background gives rise to two-dimensional effective degrees of freedom. By compactifying the theory on the circle fibers of two cigar-like manifolds, we find that a natural candidate for the effective theory is a chiral gauged WZW model. The symmetry algebra of the model contains the W-algebra that appears on the two-dimensional side of the AGT correspondence. We show that the expectation values of its currents determine the Seiberg-Witten curve of the four-dimensional side.

  6. Modeling Background Attenuation by Sample Matrix in Gamma Spectrometric Analyses

    SciTech Connect (OSTI)

    Bastos, Rodrigo O.; Appoloni, Carlos R. [Applied Nuclear Physics Laboratory-Department of Physics-CCE-State University of Londrina Campus Universitario-Rodovia Celso Garcia Cid s/n, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil)

    2008-08-07

    In laboratory gamma spectrometric analyses, the procedures for estimating background usually overestimate it. If an empty container similar to that used to hold samples is measured, it does not consider the background attenuation by sample matrix. If a 'blank' sample is measured, the hypothesis that this sample will be free of radionuclides is generally not true. The activity of this 'blank' sample is frequently sufficient to mask or to overwhelm the effect of attenuation so that the background remains overestimated. In order to overcome this problem, a model was developed to obtain the attenuated background from the spectrum acquired with the empty container. Beyond reasonable hypotheses, the model presumes the knowledge of the linear attenuation coefficient of the samples and its dependence on photon energy and samples densities. An evaluation of the effects of this model on the Lowest Limit of Detection (LLD) is presented for geological samples placed in cylindrical containers that completely cover the top of an HPGe detector that has a 66% relative efficiency. The results are presented for energies in the range of 63 to 2614keV, for sample densities varying from 1.5 to 2.5 g{center_dot}cm{sup -3}, and for the height of the material on the detector of 2 cm and 5 cm. For a sample density of 2.0 g{center_dot}cm{sup -3} and with a 2cm height, the method allowed for a lowering of 3.4% of the LLD for the energy of 1460keV, from {sup 40}K, 3.9% for the energy of 911keV from {sup 228}Ac, 4.5% for the energy of 609keV from {sup 214}Bi, and8.3% for the energy of 92keV from {sup 234}Th. For a sample density of 1.75 g{center_dot}cm{sup -3} and a 5cm height, the method indicates a lowering of 6.5%, 7.4%, 8.3% and 12.9% of the LLD for the same respective energies.

  7. Scalar waves on a naked-singularity background

    E-Print Network [OSTI]

    John G. Stalker; A. Shadi Tahvildar-Zadeh

    2004-04-01

    We obtain global space-time weighted-L^2 (Morawetz) and L^4 (Strichartz) estimates for a massless chargeless scalar field propagating on a super-extremal (overcharged) Reissner-Nordstrom background. We begin by discussing the question of well-posedness of the Cauchy problem for scalar fields on non-globally hyperbolic manifolds and the role played by the Friedrichs extension, go over the construction of the function spaces involved, show how to transform the problem to one about the wave equation on the Minkowski space with a singular potential, and finally prove that the potential thus obtained satisfies the various conditions needed in order for the estimates to hold.

  8. Low energy neutron background in deep underground laboratories

    E-Print Network [OSTI]

    Andreas Best; Joachim Gorres; Matthias Junker; Karl-Ludwig Kratz; Matthias Laubenstein; Alexander Long; Stefano Nisi; Karl Smith; Michael Wiescher

    2015-09-02

    The natural neutron background influences the maximum achievable sensitivity in most deep underground nuclear, astroparticle and double-beta decay physics experiments. Reliable neutron flux numbers are an important ingredient in the design of the shielding of new large-scale experiments as well as in the analysis of experimental data. Using a portable setup of He-3 counters we measured the thermal neutron flux at the Kimballton Underground Research Facility, the Soudan Underground Laboratory, on the 4100 ft and the 4850 ft levels of the Sanford Underground Research Facility, at the Waste Isolation Pilot Plant and at the Gran Sasso National Laboratory. Absolute neutron fluxes at these laboratories are presented.

  9. Low energy neutron background in deep underground laboratories

    E-Print Network [OSTI]

    Best, Andreas; Junker, Matthias; Kratz, Karl-Ludwig; Laubenstein, Matthias; Long, Alexander; Nisi, Stefano; Smith, Karl; Wiescher, Michael

    2015-01-01

    The natural neutron background influences the maximum achievable sensitivity in most deep underground nuclear, astroparticle and double-beta decay physics experiments. Reliable neutron flux numbers are an important ingredient in the design of the shielding of new large-scale experiments as well as in the analysis of experimental data. Using a portable setup of He-3 counters we measured the thermal neutron flux at the Kimballton Underground Research Facility, the Soudan Underground Laboratory, on the 4100 ft and the 4850 ft levels of the Sanford Underground Research Facility, at the Waste Isolation Pilot Plant and at the Gran Sasso National Laboratory. Absolute neutron fluxes at these laboratories are presented.

  10. Pairs Emission in a Uniform Background Field: an Algebraic Approach

    E-Print Network [OSTI]

    Roberto Soldati

    2011-06-23

    A fully algebraic general approach is developed to treat the pairs emission and absorption in the presence of some uniform external background field. In particular, it is shown that the pairs production and annihilation operators, together with the pairs number operator, do actually fulfill the SU(2) functional Lie algebra. As an example of application, the celebrated Schwinger formula is consistently and nicely recovered, within this novel approach, for a Dirac spinor field in the presence of a constant and homogeneous electric field in four spacetime dimensions.

  11. Summaries of Subscription Workgroup Meetings (sub/background)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect PhotovoltaicsStructureInnovationEnergy Conversion |EnergyEnergyBackground

  12. UBS AG, LONDON BRANCH Order No. EA-261 I. BACKGROUND

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann Jackson About1996HowFOAShowing YouNeedof Energy Fish andSmugglingSecond1 I. BACKGROUND

  13. 10:30AM TODAY: Senior Administration Officials to Hold a Background...

    Energy Savers [EERE]

    TODAY: Senior Administration Officials to Hold a Background Conference Call Regarding Oil 10:30AM TODAY: Senior Administration Officials to Hold a Background Conference Call...

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

    E-Print Network [OSTI]

    Takahashi, Yuki David

    2010-01-01

    18 Microwave absorbers candidates for1.4.2 Cosmic microwave background polarization 1.4.3 Curl-Measurement of Cosmic Microwave Background Polarization

  15. The POLARBEAR Cosmic Microwave Background Polarization Experiment and Anti-Reflection Coatings for Millimeter Wave Observations

    E-Print Network [OSTI]

    Quealy, Erin

    2012-01-01

    Tables 1 The Cosmic Microwave Background as a CosmologicalFour-Year COBE DMR Cosmic Microwave Background Observations:First-Year Wilkinson Microwave Anisotropy Probe (WMAP)

  16. On the omnipresent background gamma radiation of the continuous spectrum

    E-Print Network [OSTI]

    R. Banjanac; D. Maleti?; D. Jokovi?; N. Veselinovi?; A. Dragi?; V. Udovi?i?; I. Ani?in

    2013-05-14

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere is studied, both in a ground level and in an underground laboratory. It is established that the continuous portion of this background spectrum is mostly due to the radiations that arrive from the upper hemisphere of the continuous spectrum similar to the instrumental one. The intensity of this radiation of an average energy of about 120 keV is estimated to about 8000 photons/m2s 2\\pi srad in a ground level laboratory, and to about 5000 photons/m2s 2\\pi srad at the depth of 25 m.w.e. Rough estimates of the dose that it contributes to the skin are about 1.5 nSv/h and 1 nSv/h respectively. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is both of cosmic and terrestrial origin, mixed in proportion that still has to be determined.

  17. On the omnipresent background gamma radiation of the continuous spectrum

    E-Print Network [OSTI]

    Banjanac, R; Jokovi?, D; Veselinovi?, N; Dragi?, A; Udovi?i?, V; Ani?in, I

    2013-01-01

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere is studied, both in a ground level and in an underground laboratory. It is established that the continuous portion of this background spectrum is mostly due to the radiations that arrive from the upper hemisphere of the continuous spectrum similar to the instrumental one. The intensity of this radiation of an average energy of about 120 keV is estimated to about 8000 photons/m2s 2\\pi srad in a ground level laboratory, and to about 5000 photons/m2s 2\\pi srad at the depth of 25 m.w.e. Rough estimates of the dose that it contributes to the skin are about 1.5 nSv/h and 1 nSv/h respectively. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is both of cosmic and terrestrial origin, mixed in proportion that still has to be determined.

  18. Supernova Neutrino Background Bound on the SFR History

    E-Print Network [OSTI]

    Khodagholizadeh, Jafar

    2015-01-01

    The purpose of the present study is to compare the predictions of different models of star formation rate (SFR) history in the universe with the upper limit of Super Kamiokande for the neutrino background. To this aim we have calculated the expected neutrino density for the most popular models of SFR history, Hogg et al. ,Glazebrook et al., Cole et al., Yuksel et al., Hernquist et al. and Kaplinghat et al. Differerent from previous studies we have used the $\\Lambda$CDM model with $\\Omega_{\\Lambda} = 0.7$. We have assumed that the detector used for the detection the neutrino flux is SuperK and also we have assumed that the electron neutrinos produced in the Supernovae oscillate equally to the three standard model flavors. By these assumptions all models stay below the upper limit of SuperK on the event rate and the detection of the supernova relic neutrino background (SRNB) remains undetected. Future neutrino detectors such as KM3Net will be able to detect the SRNB and distinguish between the models of the SFR...

  19. Membrane solitons in eight-dimensional hyper-Kaehler backgrounds

    E-Print Network [OSTI]

    Ruben Portugues

    2003-12-16

    We derive the BPS equations satisfied by lump solitons in $(2+1)$-dimensional sigma models with toric 8-dimensional hyper-K\\"ahler (${HK}_8$) target spaces and check they preserve 1/2 of the supersymmetry. We show how these solitons are realised in M theory as M2-branes wrapping holomorphic 2-cycles in the $\\bE^{1,2}\\times {HK}_8$ background. Using the $\\kappa$-symmetry of a probe M2-brane in this background we determine the supersymmetry they preserve, and note that there is a discrepancy in the fraction of supersymmetry preserved by these solitons as viewed from the low energy effective sigma model description of the M2-brane dynamics or the full M theory. Toric ${HK}_8$ manifolds are dual to a Hanany-Witten setup of D3-branes suspended between 5-branes. In this picture the lumps correspond to vortices of the three dimensional ${\\mathcal N}=3$ or ${\\mathcal N}=4$ theory.

  20. Measurements of Worldwide Radioxenon Backgrounds - The "EU" Project

    SciTech Connect (OSTI)

    Bowyer, Ted W.; Cooper, Matthew W.; Hayes, James C.; Forrester, Joel B.; Haas, Derek A.; Hansen, Randy R.; Keller, Paul E.; Kirkham, Randy R.; Lidey, Lance S.; McIntyre, Justin I.; Miley, Harry S.; Payne, Rosara F.; Saey, Paul R.; Thompson, Robert C.; Woods, Vincent T.; Williams, Richard M.

    2009-09-24

    Under the Comprehensive Nuclear-Test-Ban Treaty (CTBT), radioactive xenon (radioxenon) measurements are one of the principle techniques used to detect nuclear underground nuclear explosions, and specifically, the presence of one or more radioxenon isotopes allows one to determine whether a suspected event was a nuclear explosion or originated from an innocent source. During the design of the International Monitoring System (IMS), which was designed as the verification mechanism for the Treaty, it was determined that radioxenon measurements should be performed at 40 or more stations worldwide. At the time of the design of the IMS, however, very few details about the background of the xenon isotopes was known and it is now recognized that the backgrounds were probably evolving anyhow. This paper lays out the beginning of a study of the worldwide concentrations of xenon isotopes that can be used to detect nuclear explosions and several sources that also release radioxenons, and will have to be accounted for during analysis of atmospheric levels. Although the global concentrations of the xenon isotopes are the scope of a much larger activity that could span over several years, this study measures radioxenon concentrations in locations where there was either very little information or there was a unique opportunity to learn more about emissions from known sources. The locations where radioxenon levels were measured and reported are included.

  1. Data series subtraction with unknown and unmodeled background noise

    E-Print Network [OSTI]

    Stefano Vitale; Giuseppe Congedo; Rita Dolesi; Valerio Ferroni; Mauro Hueller; Daniele Vetrugno; William Joseph Weber; Heather Audley; Karsten Danzmann; Ingo Diepholz; Martin Hewitson; Natalia Korsakova; Luigi Ferraioli; Ferran Gibert; Nikolaos Karnesis; Miquel Nofrarias; Henri Inchauspe; Eric Plagnol; Oliver Jennrich; Paul W. McNamara; Michele Armano; James Ira Thorpe; Peter Wass

    2014-08-04

    LISA Pathfinder (LPF), ESA's precursor mission to a gravitational wave observatory, will measure the degree to which two test-masses can be put into free-fall, aiming to demonstrate a residual relative acceleration with a power spectral density (PSD) below 30 fm/s$^2$/Hz$^{1/2}$ around 1 mHz. In LPF data analysis, the measured relative acceleration data series must be fit to other various measured time series data. This fitting is required in different experiments, from system identification of the test mass and satellite dynamics to the subtraction of noise contributions from measured known disturbances. In all cases, the background noise, described by the PSD of the fit residuals, is expected to be coloured, requiring that we perform such fits in the frequency domain. This PSD is unknown {\\it a priori}, and a high accuracy estimate of this residual acceleration noise is an essential output of our analysis. In this paper we present a fitting method based on Bayesian parameter estimation with an unknown frequency-dependent background noise. The method uses noise marginalisation in connection with averaged Welch's periodograms to achieve unbiased parameter estimation, together with a consistent, non-parametric estimate of the residual PSD. Additionally, we find that the method is equivalent to some implementations of iteratively re-weighted least-squares fitting. We have tested the method both on simulated data of known PSD, and to analyze differential acceleration from several experiments with the LISA Pathfinder end-to-end mission simulator.

  2. Plasma tomographic reconstruction from tangentially viewing camera with background subtraction

    SciTech Connect (OSTI)

    Odstr?il, M.; Mlyná?, J.; Weinzettl, V.; Há?ek, P.; Verdoolaege, G.; Berta, M.

    2014-01-15

    Light reflections are one of the main and often underestimated issues of plasma emissivity reconstruction in visible light spectral range. Metallic and other specular components of tokamak generate systematic errors in the optical measurements that could lead to wrong interpretation of data. Our analysis is performed at data from the tokamak COMPASS. It is a D-shaped tokamak with specular metallic vessel and possibility of the H-mode plasma. Data from fast visible light camera were used for tomographic reconstruction with background reflections subtraction to study plasma boundary. In this article, we show that despite highly specular tokamak wall, it is possible to obtain a realistic reconstruction. The developed algorithm shows robust results despite of systematic errors in the optical measurements and calibration. The motivation is to obtain an independent estimate of the plasma boundary shape.

  3. Standard Clock in Primordial Density Perturbations and Cosmic Microwave Background

    E-Print Network [OSTI]

    Xingang Chen; Mohammad Hossein Namjoo

    2014-08-27

    Standard Clocks in the primordial epoch leave a special type of features in the primordial perturbations, which can be used to directly measure the scale factor of the primordial universe as a function of time a(t), thus discriminating between inflation and alternatives. We have started to search for such signals in the Planck 2013 data using the key predictions of the Standard Clock. In this Letter, we summarize the key predictions of the Standard Clock and present an interesting candidate example in Planck 2013 data. Motivated by this candidate, we construct and compute full Standard Clock models and use the more complete prediction to make more extensive comparison with data. Although this candidate is not yet statistically significant, we use it to illustrate how Standard Clocks appear in Cosmic Microwave Background and how they can be further tested by future data. We also use it to motivate more detailed theoretical model building.

  4. Background-reducing X-ray multilayer mirror

    DOE Patents [OSTI]

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

    1992-01-01

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

  5. Intersecting nonextreme p-branes and linear dilaton background

    SciTech Connect (OSTI)

    Chen, C.-M.; Gal'tsov, Dmitri V.; Ohta, Nobuyoshi

    2005-08-15

    We construct the general static solution to the supergravity action containing gravity, the dilaton and a set of antisymmetric forms describing the intersecting branes delocalized in the relative transverse dimensions. The solution is obtained by reducing the system to a set of separate Liouville equations (the intersection rules implying the separability); it contains the maximal number of free parameters corresponding to the rank of the differential equations. Imposing the requirement of the absence of naked singularities, we show that the general configurations are restricted to two and only two classes: the usual asymptotically flat intersecting branes, and the intersecting branes some of which are asymptotically flat and some approach the linear dilaton background at infinity. In both cases the configurations are black. These are supposed to be relevant for the description of the thermal phase of the QFT's in the corresponding Domain-Wall/QFT duality.

  6. The microlocal spectrum condition, initial value formulations and background independence

    E-Print Network [OSTI]

    Alexander Stottmeister; Thomas Thiemann

    2015-04-09

    We analyze the implications of the microlocal spectrum/Hadamard condition for states in a (linear) quantum field theory on a globally hyperbolic spacetime $M$ in the context of a (distributional) initial value formulation. More specifically, we work in a $3+1$-split $M\\cong\\mathbb{R}\\times\\Sigma$ and give a bound, independent of the spacetime metric, on the wave front sets of the initial data for a quasi-free Hadamard state in the quantum field theory defined by a normally hyperbolic differential operator $P$ acting in a vector bundle $E\\stackrel{\\pi}{\\rightarrow}M$. This aims at a possible way to apply the concept of Hadamard states within approaches to quantum field theory/gravity relying on a Hamiltonian formulation, potentially without a (classical) background metric $g$.

  7. Dynamic Black Holes in a FRW background: Lemaitre transformations

    E-Print Network [OSTI]

    H. Moradpour; A. Dehghani; M. T. Mohammadi Sabet

    2015-04-28

    Since the conformal transformations of metric do not change its causal structure, we use these transformations to embed the Lemaitre metrics into the FRW background. In our approach, conformal transformation is in agreement with the universe expansion regimes. Indeed, we use the Lemaitre metrics because the horizon singularity is eliminated in these metrics. For our solutions, there is an event horizon while its physical radii is increasing as a function of the universe expansion provided suitable metrics for investigating the effects of the universe expansion on the Black Holes. In addition, the physical and mathematical properties of the introduced metrics have well-defined behavior on the event horizon. Moreover, some physical and mathematical properties of the introduced metrics have been addressed.

  8. Massloss of galaxies due to a UV-background

    E-Print Network [OSTI]

    Takashi Okamoto; Liang Gao; Tom Theuns

    2008-07-25

    We perform cosmological hydrodynamic simulations to determine to what extent galaxies lose their gas due to photoheating from an ionizing background. We find that the characteristic mass at which haloes on average have lost half of their baryons is Mc ~ 6.5 x 10^9 Msun/h at z = 0, which corresponds to a circular velocity of 25 km/s. This is significantly lower than the filtering mass obtained by the linear theory, which is often used in semianalytical models of galaxy formation. We demonstrate it is the gas temperature at the virial radius which determines whether a halo can accrete gas. A simple model that follows the merger history of the dark matter progenitors, and where gas accretion is not allowed when this temperature is higher than the virial temperature of the halo, reproduces the results from the simulation remarkably well. This model can be applied to any reionization history, and is easy to incorporate in semianalytical models.

  9. Physics validation studies for muon collider detector background simulations

    SciTech Connect (OSTI)

    Morris, Aaron Owen; /Northern Illinois U.

    2011-07-01

    Within the broad discipline of physics, the study of the fundamental forces of nature and the most basic constituents of the universe belongs to the field of particle physics. While frequently referred to as 'high-energy physics,' or by the acronym 'HEP,' particle physics is not driven just by the quest for ever-greater energies in particle accelerators. Rather, particle physics is seen as having three distinct areas of focus: the cosmic, intensity, and energy frontiers. These three frontiers all provide different, but complementary, views of the basic building blocks of the universe. Currently, the energy frontier is the realm of hadron colliders like the Tevatron at Fermi National Accelerator Laboratory (Fermilab) or the Large Hadron Collider (LHC) at CERN. While the LHC is expected to be adequate for explorations up to 14 TeV for the next decade, the long development lead time for modern colliders necessitates research and development efforts in the present for the next generation of colliders. This paper focuses on one such next-generation machine: a muon collider. Specifically, this paper focuses on Monte Carlo simulations of beam-induced backgrounds vis-a-vis detector region contamination. Initial validation studies of a few muon collider physics background processes using G4beamline have been undertaken and results presented. While these investigations have revealed a number of hurdles to getting G4beamline up to the level of more established simulation suites, such as MARS, the close communication between us, as users, and the G4beamline developer, Tom Roberts, has allowed for rapid implementation of user-desired features. The main example of user-desired feature implementation, as it applies to this project, is Bethe-Heitler muon production. Regarding the neutron interaction issues, we continue to study the specifics of how GEANT4 implements nuclear interactions. The GEANT4 collaboration has been contacted regarding the minor discrepancies in the neutron interaction cross sections for boron. While corrections to the data files themselves are simple to implement and distribute, it is quite possible, however, that coding changes may be required in G4beamline or even in GEANT4 to fully correct nuclear interactions. Regardless, these studies are ongoing and future results will be reflected in updated releases of G4beamline.

  10. A new measurement of the cosmic X-ray background

    E-Print Network [OSTI]

    A. Moretti; C. Pagani; G. Cusumano; S. Campana; M. Perri; A. Abbey; M. Ajello; A. P. Beardmore; D. Burrows; G. Chincarini; O. Godet; C. Guidorzi; J. E. Hill; J. Kennea; J. Nousek; J. P. Osborne; G. Tagliaferri

    2008-12-09

    We present a new measurement of the cosmic X-ray background (CXRB) in the 1.5-7 keV energy band, performed by exploiting the Swift X-ray telescope (XRT) data archive. We also present a CXRB spectral model in a wider energy band (1.5-200 keV), obtained by combining these data with the recently published Swift-BAT measurement. From the XRT archive we collect a complete sample of 126 high Galactic latitude gamma-ray burst (GRB) follow-up observations. This provides a total exposure of 7.5 Ms and a sky-coverage of 7 square degrees which represents a serendipitous survey, well suited for a direct measurement of the CXRB in the 1.5-10 keV interval. Our work is based on a complete characterization of the instrumental background and an accurate measurement of the stray-light contamination and vignetting calibration. We find that the CXRB spectrum in the 1.5-7 keV energy band can be equally well fitted by a single power-law with photon index Gamma=1.47+/-0.07 or a single power-law with photon index Gamma=1.41+/-0.06 and an exponential roll-off at 41 keV. The measured flux in the 2-10 keV energy band is 2.18+/-0.13 E-11 erg/(cm2 s deg2) in the 2-10 keV band. Combining Swift-XRT with Swift-BAT (15-200 keV) we find that, in the 1.5-200 keV band, the CXRB spectrum can be well described by two smoothly-joined power laws with the energy break at 29.0+/-0.5 keV corresponding to a nu F_nu peak located at 22.4+/-0.4 keV. Taking advantage of both the Swift high energy instruments (XRT and BAT), we produce an analytical description of the CXRB spectrum over a wide (1.5-200 keV) energy band. This model is marginally consistent with the HEAO1 measurement (~10% higher at energies higher than 20 keV, while it is significantly (30%) higher at low energies (2-10 keV).

  11. Cosmic acceleration without dark energy: background tests and thermodynamic analysis

    SciTech Connect (OSTI)

    Lima, J.A.S.; Graef, L.L.; Pavón, D.; Basilakos, Spyros E-mail: leilagraef@usp.br E-mail: svasil@academyofathens.gr

    2014-10-01

    A cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associated with the cold dark matter component. The model can be interpreted as an attempt to reduce the so-called cosmic sector (dark matter plus dark energy) and relate the two cosmic accelerating phases (early and late time de Sitter expansions). A detailed thermodynamic analysis including possible quantum corrections is also carried out. For a very wide range of the free parameters, it is found that the model presents the expected behavior of an ordinary macroscopic system in the sense that it approaches thermodynamic equilibrium in the long run (i.e., as it nears the second de Sitter phase). Moreover, an upper bound is found for the Gibbons–Hawking temperature of the primordial de Sitter phase. Finally, when confronted with the recent observational data, the current 'quasi'-de Sitter era, as predicted by the model, is seen to pass very comfortably the cosmic background tests.

  12. Is the low-l microwave background cosmic?

    E-Print Network [OSTI]

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

    2004-11-24

    The large-angle (low-l) correlations of the Cosmic Microwave Background exhibit several statistically significant anomalies compared to the standard inflationary big-bang model, however no connection has hitherto been drawn between them. Here we show that the quadrupole and octopole are far more correlated (99.97% C.L.) than previously thought. The quadrupole plane and the three octopole planes are remarkably aligned. Three of these planes are orthogonal to the ecliptic at a level inconsistent with gaussian random statistically isotropic skies at 99.8% C.L., and the normals to these planes are aligned at 99.9% C.L. with the direction of the cosmological dipole and with the equinoxes. The remaining octopole plane is orthogonal to the supergalactic plane at >99.9% C.L. In a combined quadrupole-octopole map, the ecliptic plane narrowly threads between a hot spot and a cold spot over approximately 1/3 of the sky, and separates the three strongest extrema (in the south ecliptic hemisphere) from the three weakest extrema (in the north ecliptic hemisphere).

  13. Gravitational wave background from Standard Model physics: Qualitative features

    E-Print Network [OSTI]

    Ghiglieri, J

    2015-01-01

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

  14. Optical emission line monitor with background observation and cancellation

    DOE Patents [OSTI]

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

    1986-01-01

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

  15. Gravitational wave background from Standard Model physics: Qualitative features

    E-Print Network [OSTI]

    J. Ghiglieri; M. Laine

    2015-07-17

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

  16. Optical emission line monitor with background observation and cancellation

    DOE Patents [OSTI]

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

    1985-01-04

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

  17. Experiments with background gas in a vacuum arc centrifuge

    SciTech Connect (OSTI)

    Dallaqua, R.S.; Simpson, S.W.; Del Bosco, E.

    1996-04-01

    Since promising isotope separation results were first reported by Krishnan et al. in 1981, a range of vacuum arc centrifuge experiments have been conducted in laboratories around the world. The PCEN (Plasma CENtrifuge) vacuum arc centrifuge at the Brazilian National Institute for Space Research has been used for isotope separation studies with cathode materials of carbon and magnesium and also to investigate the performance in terms of the rotational velocity attained for different cathode materials. Here, a vacuum arc centrifuge has been operated with an initial filling gas of either argon or hydrogen for pressures ranging from 10{sup {minus}3} to 10{sup {minus}1} Pa. The angular velocity {omega} of the plasma has been determined by cross-correlating the signals from potential probes, and the electron temperature T has been deduced from Langmuir probe data. At high gas pressures and early times during the 14 ms plasma lifetime, high-frequency nonuniformities frequently observed in the vacuum discharge disappear, suggesting that the associated instability is suppressed. Under the same conditions, nonuniformities rotating with much lower angular velocities are observed in the plasma. Temperatures are reduced in the presence of the background gas, and the theoretical figure of merit for separation proportional to {omega}{sup 2}/T is increased compared to its value in the vacuum discharge for both argon and hydrogen gas fillings.

  18. Reissner-Nordstrom black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-11-29

    In this paper we propose a stationary solution of Einstein's field equations describing Reissner-Nordstrom black hole in dark energy background. It is to be regarded as the Reissner-Nordstrom black hole is embedded into the dark energy solution producing Reissner-Nordstrom-dark energy black hole. We find that the space-time geometry of Reissner-Nordstrom-dark energy solution is Petrov type $D$ in the classification of space-times. It is also shown that the embedded space-time possesses an energy-momentum tensor of the electromagnetic field interacting with the dark energy having negative pressure. We find the energy-momentum tensor for dark energy violates the the strong energy condition due to the negative pressure, whereas that of the electromagnetic field obeys the strong energy condition. It is shown that the time-like vector field for an observer in the Reissner-Nordstrom-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity of the horizons for the embedded dark energy black hole. The characteristic properties of relativistic dark energy based on the de Sitter solution is discussed in an appendix.

  19. Spectral distortions in the cosmic microwave background polarization

    SciTech Connect (OSTI)

    Renaux-Petel, Sébastien [Laboratoire de Physique Théorique et Hautes Energies, Université Pierre and Marie Curie - Paris VI, CNRS-UMR 7589, 4 place Jussieu, Paris, 75252 (France); Fidler, Christian [Institute of Cosmology and Gravitation, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Pitrou, Cyril [Sorbonne Universités, Institut Lagrange de Paris, 98 bis Bd Arago, Paris, 75014 (France); Pettinari, Guido W., E-mail: srenaux@lpthe.jussieu.fr, E-mail: christian.fidler@port.ac.uk, E-mail: pitrou@iap.fr, E-mail: g.pettinari@sussex.ac.uk [Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom)

    2014-03-01

    We compute the spectral distortions of the Cosmic Microwave Background (CMB) polarization induced by non-linear effects in the Compton interactions between CMB photons and the flow of intergalactic electrons. This signal is of the y-type and is dominated by contributions arising from the reionized era. We stress that it is not shadowed by the thermal SZ effect which has no equivalent for polarization. We decompose its angular dependence into E- and B-modes, and we calculate the corresponding power spectra, both exactly and using a suitable Limber approximation that allows a simpler numerical evaluation. We find that B-modes are of the same order of magnitude as E-modes. Both spectra are relatively flat, peaking around ? = 280, and their overall amplitude is directly related to the optical depth to reionization. Moreover, we find this effect to be one order of magnitude larger than the non-linear kinetic Sunyaev-Zel'dovich effect in galaxy clusters. Finally, we discuss how to improve the detectability of our signal by cross-correlating it with other quantities sourced by the flow of intergalactic electrons.

  20. Non-geometric Backgrounds Based on Topological Interfaces

    E-Print Network [OSTI]

    Yuji Satoh; Yuji Sugawara

    2015-07-03

    We study simple models of the world-sheet CFTs describing non-geometric backgrounds based on the topological interfaces, the `gluing condition' of which imposes T-duality- or analogous twists. To be more specific, we start with the torus partition function on a target space S^1 [base] x (S^1 x S^1) [fiber] with rather general values of radii. The fiber CFT is defined by inserting the twist operators consisting of the topological interfaces which lie along the cycles of the world-sheet torus according to the winding numbers of the base circle. We construct the partition functions involving such duality twists. The modular invariance is achieved straightforwardly, whereas `unitarization' is generically necessary to maintain the unitarity. We demonstrate it in the case of the equal fiber radii. The resultant models are closely related to the CFTs with the discrete torsion. The unitarization is also physically interpreted as multiple insertions of the twist/interface operators along various directions.

  1. 524 IEEE Transactionson Nuclear Science, Vol. 35, No. 1, February 1988 BACKGROUND EVENTS IN MICROCHANNEL PLATES

    E-Print Network [OSTI]

    Wargelin, Bradford J.

    indicated that this may be due to increased background which results from outgassing of MCP's which have, after undergoing the outgassing processes described. We have assessed the background rate for a wide

  2. Background and Motivation Literature The Model Examples Summary Sustainable Supply Chain Network Design

    E-Print Network [OSTI]

    Nagurney, Anna

    Background and Motivation Literature The Model Examples Summary Sustainable Supply Chain Network and Motivation Literature The Model Examples Summary Acknowledgments The first author's research was supported Sustainable Supply Chain Network Design #12;Background and Motivation Literature The Model Examples Summary

  3. Infrared radiometry-based background-compensated thermometric instrument for noncontact temperature and friction measurements

    E-Print Network [OSTI]

    Mandelis, Andreas

    Infrared radiometry-based background-compensated thermometric instrument for noncontact temperature and performance of a novel thermometric instrument featuring thermal- emission-intensity harmonic modulation, noncontact infrared radiometric detection, and stray background suppression is described. The instrumental

  4. Zheng, Wang, Nihan, and Hallenbeck 1 Extracting Roadway Background Image: a Mode-Based Approach

    E-Print Network [OSTI]

    Washington at Seattle, University of

    space (4). The background image can also be updated with a Kalman filter-based adaptive model to accommodate the change of lighting conditions (5). Therefore, the background image must be known to run

  5. Background proportional enhancement of the extended fine structure in nonresonant inelastic x-ray scattering

    E-Print Network [OSTI]

    Seidler, Gerald T.

    Background proportional enhancement of the extended fine structure in nonresonant inelastic x is proportional to the strong q-dependent evolution in shape and magnitude of the atomic background. This en

  6. Science Background for the Reprocessing and Goddard Satellite-based Surface Turbulent Fluxes

    E-Print Network [OSTI]

    1 Science Background for the Reprocessing and Goddard Satellite-based Surface Turbulent Fluxes, MD 20771 USA #12;2 Science Background for the Reprocessing and Goddard Satellite-based Surface

  7. Basin-Scale Opportunity Assessment Initiative Background Literature Review

    SciTech Connect (OSTI)

    Saulsbury, Bo; Geerlofs, Simon H.; Cada, Glenn F; Bevelhimer, Mark S

    2010-10-01

    As called for in the March 24, 2010, Memorandum of Understanding (MOU) for Hydropower, the U.S. Department of Energy (DOE), the U.S. Department of the Interior (DOI), the U.S. Army Corps of Engineers (USACE), environmental stakeholders, and the hydropower industry are collaborating to identify opportunities to simultaneously increase electricity generation and improve environmental services in river basins of the United States. New analytical tools provide an improved ability to understand, model, and visualize environmental and hydropower systems. Efficiencies and opportunities that might not be apparent in site-by-site analyses can be revealed through assessments at the river-basin scale. Information from basin-scale assessments could lead to better coordination of existing hydropower projects, or to inform siting decisions (e.g., balancing the removal of some dams with the construction of others), in order to meet renewable energy production and environmental goals. Basin-scale opportunity assessments would inform energy and environmental planning and address the cumulative effects of hydropower development and operations on river basin environmental quality in a way that quantifies energy-environment tradeoffs. Opportunity assessments would create information products, develop scenarios, and identify specific actions that agencies, developers, and stakeholders can take to locate new sustainable hydropower projects, increase the efficiency and environmental performance of existing projects, and restore and protect environmental quality in our nation's river basins. Government agencies and non-governmental organizations (NGO) have done significant work to understand and assess opportunities for both hydropower and environmental protection at the basin scale. Some initiatives have been successful, others less so, and there is a need to better understand the legacy of work on which this current project can build. This background literature review is intended to promote that understanding. The literature review begins with a discussion in Section 2.0 of the Federal regulatory processes and mission areas pertaining to hydropower siting and licensing at the basin scale. This discussion of regulatory processes and mission areas sets the context for the next topic in Section 3.0, past and ongoing basin-scale hydropower planning and assessment activities. The final sections of the literature review provide some conclusions about past and ongoing basin-scale activities and their relevance to the current basin-scale opportunity assessment (Section 4.0), and a bibliography of existing planning and assessment documents (Section 5.0).

  8. Systematic Assessment of Neutron and Gamma Backgrounds Relevant to Operational Modeling and Detection Technology Implementation

    SciTech Connect (OSTI)

    Archer, Daniel E.; Hornback, Donald Eric; Johnson, Jeffrey O.; Nicholson, Andrew D.; Patton, Bruce W.; Peplow, Douglas E.; Miller, Thomas Martin; Ayaz-Maierhafer, Birsen

    2015-01-01

    This report summarizes the findings of a two year effort to systematically assess neutron and gamma backgrounds relevant to operational modeling and detection technology implementation. The first year effort focused on reviewing the origins of background sources and their impact on measured rates in operational scenarios of interest. The second year has focused on the assessment of detector and algorithm performance as they pertain to operational requirements against the various background sources and background levels.

  9. MULTI-SPECTRAL DOCUMENT IMAGE BINARIZATION USING IMAGE FUSION AND BACKGROUND SUBTRACTION TECHNIQUES

    E-Print Network [OSTI]

    Mitianoudis, Nikolaos

    is proposed by Gatos et al. (GPP) [3], where the document background is estimated by an adaptive threshold

  10. Music and Speed of Processing 1 BACKGROUND MUSIC AND SPEED OF PROCESSING

    E-Print Network [OSTI]

    Mutlu, Onur

    Music and Speed of Processing 1 BACKGROUND MUSIC AND SPEED OF PROCESSING Effects of the Type of Loud Background Music on Speed of Processing Onur Mutlu University of Michigan #12;Music and Speed of background music and task difficulty on the speed of processing in search tasks. Subjects completed four

  11. Graphene Nucleation Density on Copper: Fundamental Role of Background Pressure Ivan Vlassiouk,*

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Graphene Nucleation Density on Copper: Fundamental Role of Background Pressure Ivan Vlassiouk the effect of background pressure and synthesis temperature on the graphene crystal sizes in chemical vapor of the background pressure and provide the activation energy for graphene nucleation in atmospheric pressure CVD (9

  12. Establishment of a Background Environmental Monitoring Station for the PNNL Campus

    SciTech Connect (OSTI)

    Fritz, Brad G.; Snyder, Sandra F.; Barnett, J. M.; Bisping, Lynn E.; Rishel, Jeremy P.

    2014-12-18

    The environmental surveillance of background levels of radionuclides and, in particular, the siting of a background environmental surveillance (monitoring) station are examined. Many published works identify and stress the need for background monitoring; however, little definitive and comprehensive information for siting a station exists. A definition of an ideal background monitoring location and the generic criteria recommended for use in establishing such a background monitoring location are proposed. There are seven primary (mandatory) criteria described with two additional, optional criteria. The criteria are applied to the Richland, Washington (WA), Pacific Northwest National Laboratory (PNNL) Campus, which currently uses background monitoring data from the nearby Hanford Site. Eleven potential background monitoring sites were identified, with one location in Benton City, WA found to meet all of the mandatory and optional criteria. It is expected that the new sampler will be installed and operating by the end of June, 2015.

  13. Development of criteria used to establish a background environmental monitoring station

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

    Fritz, Brad G.; Barnett, J. Matthew; Snyder, Sandra F.; Bisping, Lynn E.; Rishel, Jeremy P.

    2015-03-02

    It is generally considered necessary to measure concentrations of contaminants-of-concern at a background location when conducting atmospheric environmental surveillance. This is because it is recognized that measurements of background concentrations can enhance interpretation of environmental monitoring data. Despite the recognized need for background measurements, there is little published guidance available that describes how to identify an appropriate atmospheric background monitoring location. This paper develops generic criteria that can guide the decision making process for identifying suitable locations for background atmospheric monitoring station. Detailed methods for evaluating some of these criteria are also provided and a case study for establishment ofmore »an atmospheric background surveillance station as part of an environmental surveillance program is described. While the case study focuses on monitoring for radionuclides, the approach is equally valid for any airborne constituent being monitored. The case study shows that implementation of the developed criteria can result in a good, defensible choice for a background atmospheric monitoring location.« less

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

    E-Print Network [OSTI]

    Qi-Ren Zhang

    2015-04-02

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

  15. A COMPARISON OF ESTIMATED AND BACKGROUND SUBSIDENCE RATES IN TEXAS-LOUISIANA GEOPRESSURED GEOTHERMAL AREAS

    E-Print Network [OSTI]

    Lee, L.M.

    2010-01-01

    and Kazmann, R. G. , 1978, Subsidence in the capital areageothermal-related subsidence rates derived from EDAW ESA111-5 Scale corpus Background Subsidence Rates Compared to

  16. Radon monitoring and early low background counting at the Sanford Underground Laboratory

    E-Print Network [OSTI]

    Thomas, K.J.

    2012-01-01

    Radon Monitoring and Early Low Background Counting at theCA 94720, USA Abstract. Radon detectors have been deployedin Lead, SD. Currently, no radon mitigation measures are in

  17. Validation of a model for Radon-induced background processes in electrostatic spectrometers

    E-Print Network [OSTI]

    Wandkowsky, N; Fränkle, F M; Glück, F; Groh, S; Mertens, S

    2013-01-01

    The Karlsruhe Tritium Neutrino (KATRIN) experiment investigating tritium beta-decay close to the endpoint with unprecedented precision has stringent requirements on the background level of less than 10^(-2) counts per second. Electron emission during the alpha-decay of Rn-219 and Rn-220 atoms in the electrostatic spectrometers of KATRIN is a serious source of background exceeding this limit. In this paper we compare extensive simulations of Rn-induced background to specific measurements with the KATRIN pre-spectrometer to fully characterize the observed Rn-background rates and signatures and determine generic Rn emanation rates from the pre-spectrometer bulk material and its vacuum components.

  18. PROBING THE COSMIC X-RAY AND MeV GAMMA-RAY BACKGROUND RADIATION...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BACKGROUND RADIATION; BLACK HOLES; CORRELATIONS; COSMIC PHOTONS; GALAXY NUCLEI; GAMMA RADIATION; HARD X RADIATION; KEV RANGE; MEV RANGE; QUASARS; SEYFERT...

  19. A MEASUREMENT OF ANISOTROPY IN THE COSMIC BACKGROUND RADIATION ON A LARGE ANGULAR SCALE AT 33 GHz

    E-Print Network [OSTI]

    Gorenstein, M.V.

    2011-01-01

    system to map the cosmic background radiation Marc V.System to Map the Cosmic Background Radiation Appendix C -map large angular scale variations in the temperature of the 3 K cosmic background radiation.

  20. Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background Behavior

    E-Print Network [OSTI]

    ARTICLE Micro-Raman Spectroscopy of Algae: Composition Analysis and Fluorescence Background performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella while acquiring Raman signals from the algae. The time dependence of fluorescence background is char

  1. William and Mary Athletics Camp Employee Disclosure and Background Release Form

    E-Print Network [OSTI]

    Lewis, Robert Michael

    _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Camp employee candidates may be required to disclose requested criminal records, job history and other information and must undergo a background check, including a criminal history or criminal conviction check and consented for the College of William and Mary (W&M) to conduct a criminal background check on you within

  2. LLAMA: An Adaptive Strategy for Utilizing Excess Energy to Perform Background Tasks on Mobile Devices

    E-Print Network [OSTI]

    Rollins, Sami

    LLAMA: An Adaptive Strategy for Utilizing Excess Energy to Perform Background Tasks on Mobile's experience but require no interactiv- ity. In an effort to conserve energy, background tasks are typically that mobile devices often begin to recharge with 30% or more of their energy remaining. The goal of this work

  3. Pollutant transport in coastal areas with and without background wind , J. Massons1

    E-Print Network [OSTI]

    Boyer, Edmond

    Pollutant transport in coastal areas with and without background wind J. Camps1 , J. Massons1 , M dispersion model are used to study the eects of a uniform large-scale wind on the dispersion of a non a background wind. A comparison between model results and measured data (wind and pollutant concentrations

  4. LArGe - Active background suppression using argon scintillation for the GERDA $0???$-experiment

    E-Print Network [OSTI]

    M. Agostini; M. Barnabé-Heider; D. Budjáš; C. Cattadori; A. Gangapshev; K. Gusev; M. Heisel; M. Junker; A. Klimenko; A. Lubashevskiy; K. Pelczar; S. Schönert; A. Smolnikov; G. Zuzel

    2015-06-11

    LArGe is a GERDA low-background test facility to study novel background suppression methods in a low-background environment, for future application in the GERDA experiment. Similar to GERDA, LArGe operates bare germanium detectors submersed into liquid argon (1 m$^3$, 1.4 tons), which in addition is instrumented with photomultipliers to detect argon scintillation light. The scintillation signals are used in anti-coincidence with the germanium detectors to effectively suppress background events that deposit energy in the liquid argon. The background suppression efficiency was studied in combination with a pulse shape discrimination (PSD) technique using a BEGe detector for various sources, which represent characteristic backgrounds to GERDA. Suppression factors of a few times $10^3$ have been achieved. First background data of LArGe with a coaxial HPGe detector (without PSD) yield a background index of (0.12$-$4.6)$\\cdot 10^{-2}$ cts/(keV$\\cdot$kg$\\cdot$y) (90% C.L.), which is at the level of GERDA Phase I. Furthermore, for the first time we monitor the natural $^{42}$Ar abundance (parallel to GERDA), and have indication for the $2\

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

    E-Print Network [OSTI]

    Timbie, Peter

    THE WHITE MOUNTAIN POLARIMETER TELESCOPE AND AN UPPER LIMIT ON COSMIC MICROWAVE BACKGROUND. Wuensche5 Received 2007 June 10; accepted 2008 March 16 ABSTRACT The White Mountain Polarimeter (WMPol microwave background. WMPol is located at an altitude of 3880 m on a plateau in the White Mountains

  6. Geometry and supersymmetry of heterotic warped flux AdS backgrounds

    E-Print Network [OSTI]

    Beck, S W; Papadopoulos, G

    2015-01-01

    We classify the geometries of the most general warped, flux AdS backgrounds of heterotic supergravity up to two loop order in sigma model perturbation theory. We show under some mild assumptions that there are no $AdS_n$ backgrounds with $n\

  7. University of Washington | Human Resources BACKGROUND REPORT DISCLOSURE AND AUTHORIZATION FORM

    E-Print Network [OSTI]

    Matrajt, Graciela

    University of Washington | Human Resources BACKGROUND REPORT DISCLOSURE AND AUTHORIZATION FORM this the information on this form carefully. It describes your rights as a consumer. The University of Washington uses Reporting Agency" (CRA) covered by the FCRA. The University of Washington uses the background reports

  8. Using Background Knowledge to Rank Itemsets Nikolaj Tatti and Michael Mampaey

    E-Print Network [OSTI]

    Antwerpen, Universiteit

    for more flexible approaches for infus- ing background knowledge. Namely, we show that we can efficiently that these statistics describe forms of data that occur in practice and have been studied in data mining. To infuse-first search strate- gies [2,21]. The drawback of frequency is that we cannot infuse any background knowledge

  9. Brunet-Derrida-Simon conjectures Background material Main results Proof overview The genealogy of branching Brownian

    E-Print Network [OSTI]

    Berestycki, Julien

    Brunet-Derrida-Simon conjectures Background material Main results Proof overview The genealogy with constant population size Conjecture 1 : the speed Conjecture 2 : timescale Conjecture 3 : Genealogy 2 Background material So what is the Bolthausen-Sznitman coalescent ? CSBP Genealogy of Neveu's CSBP BBM 3 Main

  10. Measurement of the background in the NEMO 3 double beta decay experiment

    E-Print Network [OSTI]

    NEMO Collaboration; J. Argyriades; R. Arnold; C. Augier; J. Baker; A. S. Barabash; M. Bongrand; G. Broudin-Bay; V. B. Brudanin; A. J. Caffrey; A. Chapon; E. Chauveau; Z. Daraktchieva; D. Durand; V. G. Egorov; N. Fatemi-Ghomi; R. Flack; A. Freshville; B. Guillon; Ph. Hubert; S. Jullian; M. Kauer; S. King; O. I. Kochetov; S. I. Konovalov; V. E. Kovalenko; D. Lalanne; K. Lang; Y. Lemi`ere; G. Lutter; F. Mamedov; Ch. Marquet; J. Martin-Albo; F. Mauger; A. Nachab; I. Nasteva; I. B. Nemchenok; F. Nova; P. Novella; H. Ohsumi; R. B. Pahlka; F. Perrot; F. Piquemal; J. L. Reyss; J. S. Ricol; R. Saakyan; X. Sarazin; L. Simard; Yu. A. Shitov; A. A. Smolnikov; S. Snow; S. S"oldner-Rembold; I. Stekl; C. S. Sutton; G. Szklarz; J. Thomas; V. V. Timkin; V. I. Tretyak; Vl. I. Tretyak; V. I. Umatov; L. V'ala; I. A. Vanyushin; V. A. Vasiliev; V. Vorobel; Ts. Vylov

    2009-03-12

    In the double beta decay experiment NEMO~3 a precise knowledge of the background in the signal region is of outstanding importance. This article presents the methods used in NEMO~3 to evaluate the backgrounds resulting from most if not all possible origins. It also illustrates the power of the combined tracking-calorimetry technique used in the experiment.

  11. Background & Publications

    E-Print Network [OSTI]

    /freeze event on Memorial Day weekend have developed frost rings around the fruit. Strawberry harvest continues

  12. Legal Background

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1.Reports1E~LONG-TERM SURVEILLANCEText of

  13. Legal Background

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1.Reports1E~LONG-TERM SURVEILLANCEText

  14. Legal Background

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and700, 1.Reports1E~LONG-TERM

  15. CAMD Background

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of raregovAboutRecovery ActToolsFor PhysicistsDepartmentMostBy theCAMD's

  16. Resonant holographic measurements of laser ablation plume expansion in vacuum and argon gas backgrounds

    SciTech Connect (OSTI)

    Lindley, R.A.

    1993-10-01

    This thesis discusses the following on resonant holographic measurements of laser ablation plume expansion: Introduction to laser ablation; applications of laser ablation; The study of plume expansion; holographic interferometry; resonant holographic interferometry; accounting for finite laser bandwidth; The solution for doppler broadening and finite bandwidth; the main optical table; the lumonics laser spot shape; developing and reconstructing the holograms; plume expansion in RF/Plasma Environments; Determining {lambda}{sub o}; resonant refraction effects; fringe shift interpretation; shot-to-shot consistency; laser ablation in vacuum and low pressure, inert, background gas; theoretically modeling plume expansion in vacuum and low pressure, inert, background gas; and laser ablation in higher pressure, inert, background gas.

  17. Next-Generation Germanium Spectrometer Background Reduction Techniques at 2 MeV

    SciTech Connect (OSTI)

    Brodzinski, Ronald L.

    2005-04-01

    The Majorana project, a next-generation 76Ge neutrinoless double-beta decay experiment being undertaken by a large international collaboration, has the goal of measuring the neutrinoless double-beta decay rate by observing monochromatic events at 2039 keV in 500 kg of isotopically enriched 76Ge gamma-ray spectrometers. In order to achieve the desired sensitivity limit, the background in the 2037-2041 keV region must be reduced to <1 event per year in the entire germanium array. The effects of various background reduction techniques, and the combination thereof, to produce a huge 76Ge spectrometer array with virtually zero background are discussed.

  18. Metric-Independent Measures for Supersymmetric Extended Object Theories on Curved Backgrounds

    E-Print Network [OSTI]

    Hitoshi Nishino; Subhash Rajpoot

    2014-11-14

    For Green-Schwarz superstring sigma-model on curved backgrounds, we introduce a non-metric measure $\\Phi \\equiv \\epsilon^{i j} \\epsilon^{I J} (\\partial_i \\varphi^I) (\\partial_j \\varphi^J)$ with two scalars $\\varphi^I (I = 1, 2)$ used in Two Measure Theory (TMT). As in the flat-background case, the string tension $T= (2 \\pi \\alpha ' )^{-1}$ emerges as an integration constant for the A_i-field equation. This mechanism is further generalized to supermembrane theory, and to super p-brane theory, both on general curved backgrounds. This shows the universal applications of dynamical measure of TMT to general supersymmetric extended objects on general curved backgrounds.

  19. Near-infrared InGaAs detectors for background-limited imaging and photometry

    E-Print Network [OSTI]

    Sullivan, Peter W.

    Originally designed for night-vision equipment, InGaAs detectors are beginning to achieve background-limited performance in broadband imaging from the ground. The lower cost of these detectors can enable multi-band ...

  20. The MAJORANA experiment: an ultra-low background search for neutrinole...

    Office of Scientific and Technical Information (OSTI)

    The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay Citation Details In-Document Search Title: The MAJORANA experiment: an ultra-low...

  1. Two Mixing Formulas Maxwell-Garnett formula (out-layer as background)

    E-Print Network [OSTI]

    Zhang, Guifu

    Two Mixing Formulas · Maxwell-Garnett formula (out-layer as background) Equivalent form--Rayleigh mixing formula · Polder-van Santern mixing formula ! "e "1 = 1+ 2 fy 1# fy ! f = NV ! y = "2 #"1 "2 + 2

  2. Radon backgrounds in the DEAP-1 liquid argon based Dark Matter detector

    E-Print Network [OSTI]

    Amaudruz, P -A; Beltran, B; Boudjemline, K; Caldwell, M G Boulay B Cai T; Chen, M; Chouinard, R; Cleveland, B T; Contreras, D; Dering, K; Duncan, F; Ford, R; Giuliani, R Gagnon F; Golovko, M Gold V V; Gorel, P; Graham, K; Grant, D R; Hakobyan, R; Hallin, A L; Harvey, P; Hearns, C; Jillings, C J; Ku?niak, M; Lawson, I; Li, O; Lidgard, J; Liimatainen, P; Lippincott, W H; Mathew, R; McDonald, A B; McElroy, T; McFarlane, K; McKinsey, D; Muir, A; Nantais, C; Nicolics, K; Nikkel, J; Noble, T; O'Dwyer, E; Olsen, K S; Ouellet, C; Pasuthip, P; Pollmann, T; Rau, W; Retiere, F; Ronquest, M; Skensved, P; Sonley, T; Vázquez-Jáuregui, E; Veloce, L; Ward, M

    2012-01-01

    The DEAP-1 \\SI{7}{kg} single phase liquid argon scintillation detector was operated underground at SNOLAB in order to test the techniques and measure the backgrounds inherent to single phase detection, in support of the DEAP-3600 Dark Matter detector. Backgrounds in DEAP are controlled through material selection, construction techniques, pulse shape discrimination and event reconstruction. This report details the analysis of background events observed in three iterations of the DEAP-1 detector, and the measures taken to reduce them. The $^{222}$Rn decay rate in the liquid argon was measured to be between 16 and \\SI{26}{\\micro\\becquerel\\per\\kilogram}. We found that the background spectrum near the region of interest for Dark Matter detection in the final DEAP-1 detector generation is well described considering events from three sources: radon daughters decaying on the surface of the active volume, the expected rate of electromagnetic events misidentified as nuclear recoils due to inefficiencies in the pulse sh...

  3. 2. GENERAL BACKGROUND ON CORALS AND CORAL REEFS 2.1 Taxonomy and Distribution

    E-Print Network [OSTI]

    5 2. GENERAL BACKGROUND ON CORALS AND CORAL REEFS 2.1 Taxonomy and Distribution 2.1.1 Taxonomy or the differentiation of gene pools when identifying and categorizing organisms in the ocean. Rather, classical taxonomy

  4. Background: Global Warming, 2009 1. Unequivocally, the climate is warming. Natural systems are affected.

    E-Print Network [OSTI]

    Minnesota, University of

    ." #12;Reducing Greenhouse Gas Emissions from Transportation Sources in Minnesota A Study gas (GHG) emissions from Minnesota's transportation sector. #12;Research Study Team UniversityBackground: Global Warming, 2009 1. Unequivocally, the climate is warming. Natural systems

  5. Linking Family Background and Home Language with English Reading Comprehension amog Bi/Multilinguals 

    E-Print Network [OSTI]

    Yulia, Astri

    2013-04-24

    The purpose of this study is to examine the links between family background and home language factors on English reading achievement among bi/multilingual students. To explore the potential predictors of English reading achievement among bi...

  6. A JOINT MODEL OF X-RAY AND INFRARED BACKGROUNDS. II. COMPTON...

    Office of Scientific and Technical Information (OSTI)

    cosmic X-ray background spectrum at 20 keV. Our model predicts that the majority (90%) of luminous and bright CT AGNs (Lsub rest2-10keV > 10sup 44 erg ssup -1 or fsub...

  7. Background studies and shielding effects for the TPC detector of the CAST experiment

    E-Print Network [OSTI]

    G. Luzón; B. Beltrán; J. M. Carmona; S. Cebrián; H. Gómez; I. G. Irastorza; J. Morales; A. Ortíz; A. Rodríguez; J. Ruz; J. A. Villar

    2007-06-12

    Sunset solar axions traversing the intense magnetic field of the CERN Axion Solar Telescope (CAST) experiment may be detected in a Time Projection Chamber (TPC) detector, as X-rays signals. These signals could be masked, however, by the inhomogeneous background of materials in the experimental site. A detailed analysis, based on the detector characteristics, the background radiation at the CAST site, simulations and experimental results, has allowed us to design a shielding which reduces the background level by a factor of ~4 compared to the detector without shielding, depending on its position, in the energy range between 1 and 10 keV. Moreover, this shielding has improved the homogeneity of background measured by the TPC.

  8. A background simulation method for cosmogenic nuclides inside HPGe detectors for rare event experiments

    E-Print Network [OSTI]

    Jian Su; Zhi Zeng; Hao Ma; Qian Yue; Jianping Cheng; Jin Li

    2013-12-05

    Cosmogenic nuclides inside germanium detectors contribute background noise spectra quite different from ordinary external sources. We propose and discuss a nuclide decay and level transition model based on graph theory to understand the background contribution of the decay of cosmogenic nuclides inside a germanium crystal. In this work, not only was the level transition process, but the detector response time was also taken into consideration to decide whether or not to apply coincidence summing-up. We simulated the background spectrum of the internal cosmogenic nuclides in a germanium detector, and found some unique phenomena caused by the coincidence summing-up effect in the simulated spectrum. Thus, the background spectrum of each cosmogenic nuclide can be quantitatively obtained.

  9. The diffusion of photovoltaics : background, modeling and initial reaction of the agricultural - irrigation sector

    E-Print Network [OSTI]

    Lilien, Gary Louis

    1978-01-01

    This paper deals with the background, development and calibration of a model of innovation-diffusion, designed to help allocate government field test and demonstration resources in support of a photovoltaic technology ...

  10. Geochemistry of Background Sediment Samples at Technical Area 39, Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Eric V. McDonald; Katherine Campbell; Patrick A. Longmire; Steven L. Reneau

    1998-11-01

    This report presents results of chemical analyses of 24 analytes in 16 background sediment samples collected from Ancho Canyon and Indio Canyon at Technical Area (TA) 39, Los Alamos National Laboratory. Preliminary upper tolerance limits (UTLS) for sediments are calculated from this data set but, because of the small sample size, these UTLs exceed the maximum values in the data set by up to 50'ZO and will require revision as more background sediment data are obtained.

  11. The cosmic gamma-ray background in the MeV range

    E-Print Network [OSTI]

    P. Ruiz-Lapuente; M. Casse; E. Vangioni-Flam

    2000-09-20

    The $\\gamma$-ray background from supernovae is calculated on the basis of the reconstructed efficiency of supernova explosions from star formation at various redshifts. The calculations presented here show how Type Ia SN rates compatible with the results of optical supernova searches give a background emission in the MeV range that can explain the extragalactic emission measured by COMPTEL and SMM. Star formation histories reaching maximum values of 0.3-0.4 M$_{\\odot}$ yr$^{-1}$ Mpc$^{-3}$ at z$\\sim$ 1.5 (and/or possibly keeping that value to higher z) give a $\\gamma$-ray background compatible with observations while they also predict the observed supernova rates per comoving volume. The $\\gamma$-ray background in the MeV range is mostly sensitive to the star formation rate at z$\\sim$ 1-2, but the activity in forming stars at even higher z has an influence as well on the absolute level of the cosmic $\\gamma$-ray background: the time elapsed by the SNe Ia progenitors until they explode has a broad distribution and the rates of SNe Ia at z$\\sim$ 1.5-2 depend on the formation frequencies of their progenitor stars at earlier epochs. The mutual consistency of predictions of optical rates and integrated emission in the $\\gamma$-ray domain place in a firm ground the Type Ia supernova identification as the astrophysical source responsible for this cosmic background

  12. Solar neutrino-electron scattering as background limitation for double beta decay

    E-Print Network [OSTI]

    N. F. de Barros; K. Zuber

    2011-09-16

    The background on double beta decay searches due to elastic electron scattering of solar neutrinos of all double beta emitters with Q-value larger than 2 MeV is calculated, taking into account survival probability and flux uncertainties of solar neutrinos. This work determines the background level to be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double beta emitter. It is also shown that the background level increases dramatically if going to lower Q-values. Furthermore, studies are done for various detector systems under consideration for next generation experiments. It was found that experiments based on loaded liquid scintillator have to expect a higher background. Within the given nuclear matrix element uncertainties any approach exploring the normal hierarchy has to face this irreducible background, which is a limitation on the minimal achievable background for purely calorimetric approaches. Large scale liquid scintillator experiments might encounter this problem already while exploring the inverted hierarchy. Potential caveats by using more sophisticated experimental setups are also discussed.

  13. Null Energy Condition violations in bimetric gravity

    E-Print Network [OSTI]

    Baccetti, Valentina; Visser, Matt

    2012-01-01

    We consider the effective stress-energy tensors for the foreground and background sectors in ghost-free bimetric gravity. By considering the symmetries of the theory, we show that the foreground and background null energy conditions (NECs) are strongly anti-correlated. In particular, the NECs can only be simultaneously fulfilled when they saturate, corresponding to foreground and background cosmological constants. In all other situations, either the foreground or the background is subject to a NEC-violating contribution to the total stress-energy.

  14. Spallation Backgrounds in Super-Kamiokande Are Made in Muon-Induced Showers

    E-Print Network [OSTI]

    Shirley Weishi Li; John F. Beacom

    2015-04-28

    Crucial questions about solar and supernova neutrinos remain unanswered. Super-Kamiokande has the exposure needed for progress, but detector backgrounds are a limiting factor. A leading component is the beta decays of isotopes produced by cosmic-ray muons and their secondaries, which initiate nuclear spallation reactions. Cuts of events after and surrounding muon tracks reduce this spallation decay background by $\\simeq 90\\%$ (at a cost of $\\simeq 20\\%$ deadtime), but its rate at 6--18 MeV is still dominant. A better way to cut this background was suggested in a Super-Kamiokande paper [Bays {\\it et al.}, Phys.~Rev.~D {\\bf 85}, 052007 (2012)] on a search for the diffuse supernova neutrino background. They found that spallation decays above 16 MeV were preceded near the same location by a peak in the apparent Cherenkov light profile from the muon; a more aggressive cut was applied to a limited section of the muon track, leading to decreased background without increased deadtime. We put their empirical discovery on a firm theoretical foundation. We show that almost all spallation decay isotopes are produced by muon-induced showers and that these showers are rare enough and energetic enough to be identifiable. This is the first such demonstration for any detector. We detail how the physics of showers explains the peak in the muon Cherenkov light profile and other Super-K observations. Our results provide a physical basis for practical improvements in background rejection that will benefit multiple studies. For solar neutrinos, in particular, it should be possible to dramatically reduce backgrounds at energies as low as 6 MeV.

  15. Measurement of Neutron Background at the Pyhasalmi mine for CUPP Project, Finland

    E-Print Network [OSTI]

    J. N. Abdurashitov; V. N. Gavrin; V. L. Matushko; A. A. Shikhin; V. E. Yants; J. Peltoniemi; T. Keranen

    2006-07-20

    A natural neutron flux is one of significant kind of background in high-sensitive underground experiments. Therefore, when scheduling a delicate underground measurements one needs to measure neutron background. Deep underground the most significant source of neutrons are the U-Th natural radioactive chains giving a fission spectrum with the temperature of 2-3 MeV. Another source is the U-Th alpha-reactions on light nuclei of mine rock giving neutrons with different spectra in the 1-15 MeV energy region. Normal basalt mine rocks contain 1 ppm g/g of U-238 and less. Deep underground those rocks produce natural neutron fluxes of 10^{-7} - 10^{-6} cm^{-2}s^{-1} above 1 MeV. To measure such a background one needs a special techniques. In the Institute for Nuclear Research, Moscow, the neutron spectrometer was developed and built which is sensitive to such a low neutron fluxes. At the end of 2001 the collection of neutron data at the Pyhasalmi mine was started for the CUPP project. During 2002 the background and rough energy spectra of neutron at underground levels 410, 660, 990 and 1410 m were measured. The result of the measurement of the neutron background at different levels of the Pyhasalmi mine is presented and discussed. Data analysis is performed in different energy ranges from thermal neutrons up to 25 MeV and above.

  16. Spallation Backgrounds in Super-Kamiokande Are Made in Muon-Induced Showers

    E-Print Network [OSTI]

    Li, Shirley Weishi

    2015-01-01

    Crucial questions about solar and supernova neutrinos remain unanswered. Super-Kamiokande has the exposure needed for progress, but detector backgrounds are a limiting factor. A leading component is the beta decays of isotopes produced by cosmic-ray muons and their secondaries, which initiate nuclear spallation reactions. Cuts of events after and surrounding muon tracks reduce this spallation decay background by $\\simeq 90\\%$ (at a cost of $\\simeq 20\\%$ deadtime), but its rate at 6 -- 18 MeV is still dominant. A better way to cut this background was suggested in a Super-Kamiokande paper [Bays {\\it et al.}, Phys.~Rev.~D {\\bf 85}, 052007 (2012)] on a search for the diffuse supernova neutrino background. They found that spallation decays above 16 MeV were preceded near the same location by a peak in the apparent Cherenkov light profile from the muon; a more aggressive cut was applied to a limited section of the muon track, leading to decreased background without increased deadtime. We put their empirical discove...

  17. CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

    SciTech Connect (OSTI)

    Keillor, M. E.; Aalseth, C. E.; Day, A. R.; Erikson, L. E.; Fast, J. E.; Glasgow, B. D.; Hoppe, E. W.; Hossbach, T. W.; Hyronimus, B. J.; Miley, H. S.; Myers, A. W.; Seifert, A.; Stavenger, T. J. [Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)

    2011-12-13

    State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}--{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g. samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g.<10{sup 5} fissions) as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

  18. CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

    SciTech Connect (OSTI)

    Keillor, Martin E.; Aalseth, Craig E.; Day, Anthony R.; Erikson, Luke E.; Fast, James E.; Glasgow, Brian D.; Hoppe, Eric W.; Hossbach, Todd W.; Hyronimus, Brian J.; Miley, Harry S.; Myers, Allan W.; Seifert, Allen; Stavenger, Timothy J.

    2011-07-14

    State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}-{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g., samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g., < 10{sup 5} fissions), as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

  19. In-orbit background of X-ray microcalorimeters and its effects on observations

    E-Print Network [OSTI]

    Lotti, S; Macculi, C; Mineo, T; Natalucci, L; Perinati, E; Piro, L; Federici, M; Martino, B

    2014-01-01

    Methods.There are no experimental data about the background experienced by microcalorimeters in the L2 orbit, and thus the particle background levels were calculated by means of Monte Carlo simulations: we considered the original design configuration and an improved configuration aimed to reduce the unrejected background, and tested them in the L2 orbit and in the low Earth orbit, comparing the results with experimental data reported by other X-ray instruments.To show the results obtainable with the improved configuration we simulated the observation of a faint, high-redshift, point source (F[0.5-10 keV]~6.4E-16 erg cm-2 s-1, z=3.7), and of a hot galaxy cluster at R200 (Sb[0.5-2 keV]=8.61E-16 erg cm-2 s-1 arcmin-2,T=6.6 keV). Results.First we confirm that implementing an active cryogenic anticoincidence reduces the particle background by an order of magnitude and brings it close to the required level.The implementation and test of several design solutions can reduce the particle background level by a further ...

  20. Development of a low background liquid scintillation counter for a shallow underground laboratory

    SciTech Connect (OSTI)

    Erchinger, Jennifer L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Orrell, John L.; Panisko, Mark E.; Warren, Glen A.; Williams, Russell O.; Wright, Michael E.

    2015-08-20

    Pacific Northwest National Laboratory has recently opened a shallow underground laboratory intended for measurement of lowconcentration levels of radioactive isotopes in samples collected from the environment. The development of a low-background liquid scintillation counter is currently underway to further augment the measurement capabilities within this underground laboratory. Liquid scintillation counting is especially useful for measuring charged particle (e.g., B, a) emitting isotopes with no (orvery weak) gamma-ray yields. The combination of high-efficiency detection of charged particle emission in a liquid scintillation cocktail coupled with the low-background environment of an appropriately-designed shield located in a clean underground laboratory provides the opportunity for increased-sensitivity measurements of a range of isotopes. To take advantage of the 35-meter water-equivalent overburden of the underground laboratory, a series of simulations have evaluated the instrumental shield design requirements to assess the possible background rate achievable. This report presents the design and background evaluation for a shallow underground, low background liquid scintillation counter design for sample measurements.

  1. The vacuum bubbles in de Sitter background and black hole pair creation

    E-Print Network [OSTI]

    Bum-Hoon Lee; Wonwoo Lee

    2009-10-07

    We study the possible types of the nucleation of vacuum bubbles. We classify vacuum bubbles in de Sitter background and present some numerical solutions. The thin-wall approximation is employed to obtain the nucleation rate and the radius of vacuum bubbles. With careful analysis we confirm that Parke's formula is also applicable to the large true vacuum bubbles. The nucleation of the false vacuum bubble in de Sitter background is also evaluated. The tunneling process in the potential with degenerate vacua is analyzed as the limiting cases of the large true vacuum bubble and false vacuum bubble. Next, we consider the pair creation of black holes in the background of bubble solutions. We obtain static bubble wall solutions of junction equation with black hole pair. The masses of created black holes are uniquely determined by the cosmological constant and surface tension on the wall. Finally, we obtain the rate of pair creation of black holes.

  2. Heterodyne coherent anti-Stokes Raman scattering by the phase control of its intrinsic background

    SciTech Connect (OSTI)

    Wang Xi; Wang Kai; Welch, George R.; Sokolov, Alexei V.

    2011-08-15

    We demonstrate the use of femtosecond laser pulse shaping for precise control of the interference between the coherent anti-Stokes Raman scattering (CARS) signal and the coherent nonresonant background generated within the same sample volume. Our technique is similar to heterodyne detection with the coherent background playing the role of the local oscillator field. In our experiment, we first apply two ultrashort (near-transform-limited) femtosecond pump and Stokes laser pulses to excite coherent molecular oscillations within a sample. After a short and controllable delay, we then apply a laser pulse that scatters off of these oscillations to produce the CARS signal. By making fine adjustments to the probe field spectral profile, we vary the relative phase between the Raman-resonant signal and the nonresonant background, and we observe a varying spectral interference pattern. These controlled variations of the measured pattern reveal the phase information within the Raman spectrum.

  3. Radon backgrounds in the DRIFT-II directional dark matter experiments

    E-Print Network [OSTI]

    Daw, E; Gauvreau, J -L; Gold, M; Harmon, L J; Landers, J M; Lee, E R; Loomba, D; Miller, E H; Murphy, A StJ; Paling, S M; Pipe, M; Robinson, M; Sadler, S; Scarff, A; Snowden-Ifft, D P; Spooner, N J C; Walker, D

    2013-01-01

    Low pressure gas Time Projection Chambers being developed for directional Dark Matter searches offer a technology with high particle identification power, combined with poten- tial to produce a definitive detection of galactic Weakly Interacting Massive Particle (WIMP) Dark Matter. A source of background events in such experiments, able to mimic genuine WIMP in- duced nuclear recoil tracks, arises from potential radon contamination and the recoils that result from associated daughter nuclei, termed Radon Progeny Recoils (RPRs). We present here experi- mental data from a long-term study of this background using the DRIFT-II directional dark matter experiment at the Boulby Underground Laboratory. By detailed examination of event classes in both spatial and time coordinates using 5.5 years of data we show ability to determine the origin of 4 specific background populations and describe development of new technology and mitigation strategies to suppress them.

  4. Intrinsic neutron background of nuclear emulsions for directional Dark Matter searches

    E-Print Network [OSTI]

    Aleksandrov, A; Buonaura, A; Consiglio, L; D'Ambrosio, N; De Lellis, G; Di Crescenzo, A; Di Marco, N; Di Vacri, M L; Furuya, S; Galati, G; Gentile, V; Katsuragawa, T; Laubenstein, M; Lauria, A; Loverre, P F; Machii, S; Monacelli, P; Montesi, M C; Naka, T; Pupilli, F; Rosa, G; Sato, O; Tioukov, V; Umemoto, A; Yoshimoto, M

    2015-01-01

    Recent developments of the nuclear emulsion technology led to the production of films with nanometric silver halide grains suitable to track low energy nuclear recoils with submicrometric length. This improvement opens the way to a directional Dark Matter detection, thus providing an innovative and complementary approach to the on-going WIMP searches. An important background source for these searches is represented by neutron-induced nuclear recoils that can mimic the WIMP signal. In this paper we provide an estimation of the contribution to this background from the intrinsic radioactive contamination of nuclear emulsions. We also report the induced background as a function of the read-out threshold, by using a GEANT4 simulation of the nuclear emulsion, showing that it amounts to about 0.02 neutrons per year per kilogram, fully compatible with the design of a 10 kg$\\times$year exposure.

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

    SciTech Connect (OSTI)

    Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H.; Orlando, T. M.; McLain, J.; Steiger, R. von

    2014-09-15

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

  6. Instant HR January 9, 2008 TOPIC: Compliance Issues -Sign Up Now for New Background Check and I-9 Training

    E-Print Network [OSTI]

    Hammack, Richard

    you need to follow for criminal records background checks and to become familiar with the federal I-9 using HireRight, the new on-line system for requesting criminal history background checks on all new

  7. Introduction/Motivation Fuchsian Groups -Background Classification Program Results/References Classification of Pairs of Fuchsian Groups

    E-Print Network [OSTI]

    Broughton, S. Allen

    Introduction/Motivation Fuchsian Groups - Background Classification Program Results Seminar - March 2, 2009 #12;Introduction/Motivation Fuchsian Groups - Background Classification Program Results/References Outline 1 Introduction/Motivation Motivation 1 - extension of actions Motivation 2

  8. (n,n?[gamma]) reactions in 6?3?,?6?5?Cu and background in 0[nu] [beta] [beta] experiments

    E-Print Network [OSTI]

    Perepelitsa, Dennis V

    2008-01-01

    Measurements of (n, xn?[gamma]) reactions in Cu are important for understanding neutroninduced background for certain underground double beta decay experiments. Neutroninduced gammas are a contribution to background for ...

  9. Measurement and reduction of low-level radon background in the KATRIN experiment

    SciTech Connect (OSTI)

    Fränkle, F. M. [F.M. Fränkle Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC (United States)] [F.M. Fränkle Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC (United States)

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c{sup 2}. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn) atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.

  10. Double parton interactions as a background to associated HW production at the Tevatron

    SciTech Connect (OSTI)

    Bandurin, Dmitry; Golovanov, Georgy; Skachkov, Nikolai

    2010-11-01

    In this paper we study events with W+jets final state, produced in double parton (DP) interactions, as a background to the associated Higgs boson (H) and W production, with H {yields} b{bar b} decay, at the Tevatron. We have found that the event yield from the DP background can be quite sizable, what necessitates a choice of selection criteria to separate the HW and DP production processes. We suggest a set of variables sensitive to the kinematics of DP and HW events. We show that these variables, being used as an input to the artificial neural network, allow one to significantly improve a sensitivity to the Higgs boson production.

  11. The Majorana experiment: an ultra-low background search for neutrinoless double-beta decay

    E-Print Network [OSTI]

    D. G. Phillips II; E. Aguayo; F. T. Avignone III; H. O. Back; A. S. Barabash; M. Bergevin; F. E. Bertrand; M. Boswell; V. Brudanin; M. Busch; Y. -D. Chan; C. D. Christofferson; J. I. Collar; D. C. Combs; R. J. Cooper; J. A. Detwiler; P. J. Doe; Y. Efremenko; V. Egorov; H. Ejiri; S. R. Elliott; J. Esterline; J. E. Fast; N. Fields; P. Finnerty; F. M. Fraenkle; V. M. Gehman; G. K. Giovanetti; M. P. Green; V. E. Guiseppe; K. Gusey; A. L. Hallin; R. Hazama; R. Henning; A. Hime; E. W. Hoppe; M. Horton; S. Howard; M. A. Howe; R. A. Johnson; K. J. Keeter; C. Keller; M. F. Kidd; A. Knecht; O. Kochetov; S. I. Konovalov; R. T. Kouzes; B. LaFerriere; B. H. LaRoque; J. Leon; L. E. Leviner; J. C. Loach; S. MacMullin; M. G. Marino; R. D. Martin; D. -M. Mei; J. Merriman; M. L. Miller; L. Mizouni; M. Nomachi; J. L. Orrell; N. R. Overman; A. W. P. Poon; G. Perumpilly; G. Prior; D. C. Radford; K. Rielage; R. G. H. Robertson; M. C. Ronquest; A. G. Schubert; T. Shima; M. Shirchenko; K. J. Snavely; D. Steele; J. Strain; K. Thomas; V. Timkin; W. Tornow; I. Vanyushin; R. L. Varner; K. Vetter; K. Vorren; J. F. Wilkerson; B. A. Wolfe; E. Yakushev; A. R. Young; C. -H. Yu; V. Yumatov; C. Zhang

    2011-11-23

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  12. The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay

    SciTech Connect (OSTI)

    Phillips, D.; Aguayo Navarrete, Estanislao; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor; Giovanetti, G. K.; Green, Matthew P.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keller, C.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2012-12-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana Experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to validate whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  13. Inhomogeneous cosmologies, the Copernican principle and the cosmic microwave background: More on the EGS theorem

    E-Print Network [OSTI]

    C. A. Clarkson; A. A. Coley; E. S. D. O'Neill; R. A. Sussman; R. K. Barrett

    2003-02-17

    We discuss inhomogeneous cosmological models which satisfy the Copernican principle. We construct some inhomogeneous cosmological models starting from the ansatz that the all the observers in the models view an isotropic cosmic microwave background. We discuss multi-fluid models, and illustrate how more general inhomogeneous models may be derived, both in General Relativity and in scalar-tensor theories of gravity. Thus we illustrate that the cosmological principle, the assumption that the Universe we live in is spatially homogeneous, does not necessarily follow from the Copernican principle and the high isotropy of the cosmic microwave background.

  14. Impact of background flow on dissolution trapping of carbon dioxide injected into saline aquifers

    E-Print Network [OSTI]

    Rapaka, Saikiran

    2011-01-01

    While there has been a large interest in studying the role of dissolution-driven free convection in the context of geological sequestration, the contribution of forced convection has been largely ignored. This manuscript considers CO$_2$ sequestration in saline aquifers with natural background flow and uses theoretical arguments to compute the critical background velocity needed to establish the forced convective regime. The theoretical arguments are supported by two dimensional high-resolution numerical simulations which demonstrate the importance of forced convection in enhancing dissolution in aquifers characterised by low Rayleigh numbers.

  15. Machine-inudced backgrounds: their origin and loads on ATLAS/CMS

    SciTech Connect (OSTI)

    Mokhov, N.V.; /Fermilab; Weiler, T.; /CERN

    2008-05-01

    A detailed analysis of machine-induced backgrounds (MIB) in the LHC collider detectors is performed with focus on origin and rates for three sources: tertiary beam halo, beam-gas interactions and kicker prefire. Particle fluxes originating from these operational and accidental beam losses are carefully calculated with the MARS15 code and presented at the entrance to the ATLAS and CMS experimental halls. It is shown that background rates in detector subsystems strongly depend on the origin of MIB, particle energy and type. Using this source term, instantaneous and integrated loads on the detectors and impact on the detector performance can be derived.

  16. Determination of the neutron fluence, the beam characteristics and the backgrounds at the CERN-PS TOF facility

    E-Print Network [OSTI]

    CERN. Geneva. ISOLDE and Neutron Time-of-Flight Experiments Committee; Andriamonje, Samuel A; Angelopoulos, Angelos; Assimakopoulos, P A; Audouin, L; Badurek, G; Bakos, G A; Bauge, E; Baumann, P; Beer, H; Benlliure, J; Benlloch, J M; Boffi, S; Boiano, A; Borcea, C; Brusegan, A; Buono, S; Calviño, F; Cambronero, C F; Cano-Ott, D; Cennini, P; Charpak, Georges; Chepel, V Yu; Colonna, N; Cortés, G; Corvi, F; Cura, J L; Czajkowski, S; Dasso, C H; David, S; De Blas, A; Delaroche, J P; Del Moral, R; De Poli, M; Della Mea, G; Derré, J; Díez, S; Dolfini, R; Durán, I; Eleftheriadis, C; Embid-Segura, M; Farget, F; Ferreira-Marques, R; Ferrari, A; Furman, W I; Goverdovski, A A; Guamegna, F; Griesmayer, E; Grudzevich, O; Guber, K H; Gundrorin, N; Gunsing, F; Hage-Ali, M; Haight, B; Harissopoulos, S V; Heil, M; Ioannides, K G; Ioannou, P; Isaev, S; Jastrzebski, J J; Jericha, E; Kadi, Y; Käppeler, F K; Kalfas, C A; Karamanis, D; Kazakov, L; Kelic, A; Ketlerov, V; Kitis, G; Köhler, P E; Konovalov, V; Kopatch, I; Kossionides, E; Lacoste, V; Leal, L C; Leeb, H; Leprêtre, A; Lopes, M I; Lozano, M; Martínez-Val, J M; Mastinu, P F; Matteucci, M F; Matveev, D V; Mengoni, A; Meunier, R; Milazzo, P M; Mínguez-Torres, E; Mitrofanov, V P; Molina, A; Mordenti, R; Mutti, P; Napiorkowski, P J; Nicolis, N G; Nolte, R; Oberhummer, Heinz; Ordine, A; Pacati, F D; Pakou, A A; Papadopoulos, I M; Papaevangelou, T; Paradelis, T; Pavlik, A; Pavlopoulos, P; Perlado, J M; Piera, M; Piksaikin, V M; Plag, R; Plompen, A; Poch, A; Policarpo, Armando; Popov, A; Popov, Yu; Pretel, C; Quaranta, A; Quesada, J M; Radermacher, E; Radici, M; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rigato, V; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Rundberg, B; Sakelliou, L; Saldaña, F; Santos, D M; Sanz, J; Savvidis, E; Savvidis, S; Schuhmacher, H; Sedyshev, P V; Serov, D; Stéphan, C; Tagliente, G; Taín, J L; Tapia, C; Tassan-Got, L; Terrani, M; Terychny, R; Tsagas, N; Tzima, A; Vardaci, E; Ventura, A; Villamarín, D; Vlachoudis, V; Voinov, A V; Voss, F; Weigmann, H; Wendler, H; Wiescher, M C; Wisshak, K; Zeinalov, S S

    2000-01-01

    Determination of the neutron fluence, the beam characteristics and the backgrounds at the CERN-PS TOF facility

  17. Background Basic methods Model-based algorithms Model-free algorithms RTI Perspectives Conclusions References Cooperative localization in sensor networks

    E-Print Network [OSTI]

    Hero, Alfred O.

    Background Basic methods Model-based algorithms Model-free algorithms RTI Perspectives Conclusions 23, 2015 1 52 #12;Background Basic methods Model-based algorithms Model-free algorithms RTI Coates (McGill) 2 52 #12;Background Basic methods Model-based algorithms Model-free algorithms RTI

  18. Background Investigation Requirement For jobs generated outside of eWork

    E-Print Network [OSTI]

    of sources, such as criminal conviction records; public court records, and when applicable, Department of Motor Vehicle records, credit reports, and verification of highest degree and, if applicable, current outline in the Fair Credit Reporting Act, 15 U.S.C. § 1681g(a), also apply to criminal background checks

  19. DEPARTMENT GUIDE FOR PROCESSING PRE-EMPLOYMENT BACKGROUND CHECKS FOR GRADUATE STUDENT EMPLOYEES

    E-Print Network [OSTI]

    Carver, Jeffrey C.

    of criminal records in a student's home country additional time may be taken securing a check will conduct a review of federal court records, municipal court records for all US addresses in the past 10 Policy, policy number 201.00 under HR Policy Manual, and Procedures for Securing Criminal Background

  20. Investigation of the hard x-ray background in backlit pinhole imagers

    SciTech Connect (OSTI)

    Fein, J. R. Holloway, J. P.; Peebles, J. L.; Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P.

    2014-11-15

    Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-? x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

  1. The Theory of Electric and Magnetic Susceptibilities: Unfinished Second Edition TEXTUAL BACKGROUND

    E-Print Network [OSTI]

    Saffman, Mark

    1 The Theory of Electric and Magnetic Susceptibilities: Unfinished Second Edition TEXTUAL BACKGROUND John Van Vleck published his classic monograph "The Theory of Electric and Magnetic, "Susceptibilities in the Old Quantum Theory, Contrasted with the New" in the original edition was to have been

  2. Background atmospheric acoustic waves from 0.01 to 0.1 Hz

    E-Print Network [OSTI]

    Nishida, Kiwamu

    Background atmospheric acoustic waves from 0.01 to 0.1 Hz K. Nishida(1), Y. Fukao (2), S. Watada (1 observation of them. In at- tempt to detect the long period acoustic waves, we installed a cross array continuous sampling records in a time period. Acoustic waves traveled from around northwest direction from 0

  3. Process Synchronisation (Bacon 9.1, 9.2) Background: Concurrent access to shared data may

    E-Print Network [OSTI]

    Sakellariou, Rizos

    1 Process Synchronisation (Bacon 9.1, 9.2) Background: Concurrent access to shared data may result: · Wait(S): while (SBacon 9.4, 9.5; 9); Signal(S2); ... ... ... Deadlocks (Bacon 17.2, 17.3; 17.4 for information) Example (semaphores) S1, S2

  4. Femtosecond resonance enhanced CARS for background-free detection of organic molecules

    E-Print Network [OSTI]

    Rebane, Aleks

    Femtosecond resonance enhanced CARS for background-free detection of organic molecules ALEKSANDER the coherent excitation profile (CEP) of resonance enhanced femto- second CARS in a model system zinc scattering (CARS), as a tool for real-time detection of molecular and biological agents, including airborne

  5. arXiv:hepph/9905551 Diphoton Background to Higgs Boson Production at the LHC

    E-Print Network [OSTI]

    Schmidt, Carl

    arXiv:hep­ph/9905551 v2 27 Apr 2000 Diphoton Background to Higgs Boson Production at the LHC section of a light Higgs boson at the CERN Large Hadron Collider demand the accurate prediction--90526 I. INTRODUCTION The direct search for the Standard Model (SM) Higgs boson at the CERN LEP collider

  6. Multitarget region tracking based on short-sight modeling of background and color distribution

    E-Print Network [OSTI]

    Mille, Julien

    as well as non-parametric modeling of color statistics, we develop an energy-minimization based approach of color statistics and shapes of objects over time and space [1][2]. Most often, the energy is derived for tracking in real scenes with cluttered backgrounds, where statistical color data is highly scattered

  7. TCells in the Presence of HIV (Part 2 of 2) Step I --Background

    E-Print Network [OSTI]

    Meade, Douglas B.

    understand the full model. The final qualitative results should be consistent with what you know about T­cellsT­Cells in the Presence of HIV (Part 2 of 2) Step I -- Background Perelson, Kerschner, and DeBoer [4] have presented a model for the interaction of T­cells and HIV. In the project ``Normal T­Cells

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

    E-Print Network [OSTI]

    Chiang, Lung-Yih

    of isothermal lines and loops of the cosmic microwave background (CMB) radiation on the sky map is studied and the fractal structure is confirmed in the radiation temperature fluctuation. We estimate the fractal exponents of Hurst exponents, He for the profile of the CMB radiation temperature, and Hc for a single isothermal

  9. On the antenna calibration of space radio instruments using the galactic background: General formulas

    E-Print Network [OSTI]

    California at Berkeley, University of

    and application to STEREO/WAVES, Radio Sci., 46, RS2008, doi:10.1029/2010RS004464. 1. Introduction [2] Radio apply these rela- tions to the antenna calibration of the STEREO/WAVES (S/WAVES) radio instrumentOn the antenna calibration of space radio instruments using the galactic background: General

  10. Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors

    SciTech Connect (OSTI)

    Hausladen, Paul; Blessinger, Christopher S; Guzzardo, Tyler; Livesay, Jake

    2012-07-01

    A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

  11. A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

    SciTech Connect (OSTI)

    Claudepierre, S. G.; O'Brien, T. P.; Blake, J. B.; Fennell, J. F.; Roeder, J. L.; Clemmons, J. H.; Looper, M. D.; Mazur, J. E.; Mulligan, T. M.; Spence, H. E.; Reeves, G. D.; Friedel, R. H. W.; Henderson, M. G.; Larsen, B. A.

    2015-07-14

    We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30–500 keV) and in regions of geospace where multi-M eV electrons are present. Inner zone protons produce contamination in all MagEIS energy channels at roughly L < 2.5. The background-corrected MagEIS electron data produce a more accurate measurement of the electron radiation belts, as most earlier measurements suffer from unquantifiable and uncorrectable contamination in this harsh region of the near-Earth space environment. These background-corrected data will also be useful for spacecraft engineering purposes, providing ground truth for the near-Earth electron environment and informing the next generation of spacecraft design models (e.g., AE9).

  12. Investigating the Performance of Solar Air Conditioning Motivation/Background Findings

    E-Print Network [OSTI]

    Sun, Yu

    Investigating the Performance of Solar Air Conditioning Motivation/Background Findings Two Building-thermal collectors We investigated 3 types of solar cooling technologies: · Air conditioning consumes 10% of all Team Members: Jing Cong Chen, Rong Xiang, Chen Ma, Wen Jie Li · Results demonstrate that solar air

  13. Detecting a stochastic background of gravitational radiation: Signal processing strategies and sensitivities

    E-Print Network [OSTI]

    Bruce Allen; Joseph D. Romano

    1997-10-27

    We analyze the signal processing required for the optimal detection of a stochastic background of gravitational radiation using laser interferometric detectors. Starting with basic assumptions about the statistical properties of a stochastic gravity-wave background, we derive expressions for the optimal filter function and signal-to-noise ratio for the cross-correlation of the outputs of two gravity-wave detectors. Sensitivity levels required for detection are then calculated. Issues related to: (i) calculating the signal-to-noise ratio for arbitrarily large stochastic backgrounds, (ii) performing the data analysis in the presence of nonstationary detector noise, (iii) combining data from multiple detector pairs to increase the sensitivity of a stochastic background search, (iv) correlating the outputs of 4 or more detectors, and (v) allowing for the possibility of correlated noise in the outputs of two detectors are discussed. We briefly describe a computer simulation which mimics the generation and detection of a simulated stochastic gravity-wave signal in the presence of simulated detector noise. Numerous graphs and tables of numerical data for the five major interferometers (LIGO-WA, LIGO-LA, VIRGO, GEO-600, and TAMA-300) are also given. The treatment given in this paper should be accessible to both theorists involved in data analysis and experimentalists involved in detector design and data acquisition.

  14. Background Data Confidence Bounds Results The other side The Effectiveness of Internet Content Filters

    E-Print Network [OSTI]

    Stark, Philip B.

    ?_r=1&nl=todaysheadlines&emc=edit_th_20120522 · Study commissioned by USDoJ re Child Online Protection CHILD PORNOGRAPHY · Exemptions for literary, artistic, and educational content, ISPs, search engines. · Requires age screen for commercial porn. · Credit card number deemed adequate proof of age. #12;Background

  15. Gravitational and non-gravitational energy: the need for background structures

    E-Print Network [OSTI]

    Wüthrich, Christian

    Gravitational and non-gravitational energy: the need for background structures Vincent Lam- tional energy within the general theory of relativity. Some aspects of the difficulties to ascribe the usual features of localization and conservation to gravitational energy are reviewed and considered

  16. Dynamics of Scalar Fields in the Background of Rotating Black Holes

    E-Print Network [OSTI]

    W. Krivan; P. Laguna; P. Papadopoulos

    1996-06-04

    A numerical study of the evolution of a massless scalar field in the background of rotating black holes is presented. First, solutions to the wave equation are obtained for slowly rotating black holes. In this approximation, the background geometry is treated as a perturbed Schwarzschild spacetime with the angular momentum per unit mass playing the role of a perturbative parameter. To first order in the angular momentum of the black hole, the scalar wave equation yields two coupled one-dimensional evolution equations for a function representing the scalar field in the Schwarzschild background and a second field that accounts for the rotation. Solutions to the wave equation are also obtained for rapidly rotating black holes. In this case, the wave equation does not admit complete separation of variables and yields a two-dimensional evolution equation. The study shows that, for rotating black holes, the late time dynamics of a massless scalar field exhibit the same power-law behavior as in the case of a Schwarzschild background independently of the angular momentum of the black hole.

  17. Tachyon Condensation on a Nonstationary D$p$-brane with Background Fields in Superstring Theory

    E-Print Network [OSTI]

    Farzin Safarzadeh-Maleki; Davoud Kamani

    2014-10-18

    Using the boundary state formalism we obtain the partition function corresponding to a dynamical (rotating-moving) D$p$-brane in the presence of electromagnetic and tachyonic background fields in the superstring theory. The instability of such D$p$-brane due to the tachyon condensation is investigated.

  18. Simulation of the White Dwarf -- White Dwarf galactic background in the LISA data

    E-Print Network [OSTI]

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

    2005-04-07

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

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

    E-Print Network [OSTI]

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

    2005-04-22

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

  20. Controlling Low-Rate Signal Path Microdischarge for an Ultra-Low-Background Proportional Counter

    SciTech Connect (OSTI)

    Mace, Emily K.; Aalseth, Craig E.; Bonicalzi, Ricco; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Myers, Allan W.; Overman, Cory T.; Seifert, Allen

    2013-05-01

    ABSTRACT Pacific Northwest National Laboratory (PNNL) has developed an ultra-low-background proportional counter (ULBPC) made of high purity copper. These detectors are part of an ultra-low-background counting system (ULBCS) in the newly constructed shallow underground laboratory at PNNL (at a depth of ~30 meters water-equivalent). To control backgrounds, the current preamplifier electronics are located outside the ULBCS shielding. Thus the signal from the detector travels through ~1 meter of cable and is potentially susceptible to high voltage microdischarge and other sources of electronic noise. Based on initial successful tests, commercial cables and connectors were used for this critical signal path. Subsequent testing across different batches of commercial cables and connectors, however, showed unwanted (but still low) rates of microdischarge noise. To control this noise source, two approaches were pursued: first, to carefully validate cables, connectors, and other commercial components in this critical signal path, making modifications where necessary; second, to develop a custom low-noise, low-background preamplifier that can be integrated with the ULBPC and thus remove most commercial components from the critical signal path. This integrated preamplifier approach is based on the Amptek A250 low-noise charge-integrating preamplifier module. The initial microdischarge signals observed are presented and characterized according to the suspected source. Each of the approaches for mitigation is described, and the results from both are compared with each other and with the original performance seen with commercial cables and connectors.

  1. Evaluation of Ultra-Low Background Materials for Uranium and Thorium Using ICP-MS

    SciTech Connect (OSTI)

    Hoppe, Eric W.; Overman, Nicole R.; LaFerriere, Brian D.

    2013-08-08

    An increasing number of physics experiments require low background materials for their construction. The presence of Uranium and Thorium and their progeny in these materials present a variety of unwanted background sources for these experiments. The sensitivity of the experiments continues to drive the necessary levels of detection ever lower as well. This requirement for greater sensitivity has rendered direct radioassay impractical in many cases requiring large quantities of material, frequently many kilograms, and prolonged counting times, often months. Other assay techniques have been employed such as Neutron Activation Analysis but this requires access to expensive facilities and instrumentation and can be further complicated and delayed by the formation of unwanted radionuclides. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a useful tool and recent advancements have increased the sensitivity particularly in the elemental high mass range of U and Th. Unlike direct radioassay, ICP-MS is a destructive technique since it requires the sample to be in liquid form which is aspirated into a high temperature plasma. But it benefits in that it usually requires a very small sample, typically about a gram. Here we will discuss how a variety of low background materials such as copper, polymers, and fused silica are made amenable to ICP-MS assay and how the arduous task of maintaining low backgrounds of U and Th is achieved.

  2. Artificial Intelligence: CS background D. Keil 7/11 David Keil, CSCI 400 Artificial Intelligence

    E-Print Network [OSTI]

    Keil, David M.

    Artificial Intelligence: CS background D. Keil 7/11 David Keil, CSCI 400 Artificial Intelligence Arrangements of data 1D. Keil Special Topics: Artificial Intelligence 1/12 2. Arrangements Topics: Artificial Intelligence 1/12 ( g ) y p * the set of all strings over L * a language (set

  3. Spectral observations of the di use FUV background with DUVE (the Di use UV

    E-Print Network [OSTI]

    Korpela, Eric J.

    battery was depleted. Observational Results The successful mission resulted in 19 images containing 4151 calibrations of the instrument background. The shutter opened images were examined for stellar contamination corrected. Where no correction was possible, the images were discarded. The sum of these images

  4. Does Chiral Fermion Coupled to a Background Dilaton Field Preserve Information?

    E-Print Network [OSTI]

    Anisur Rahaman

    2010-09-27

    A model where chiral boson is coupled to a background dilaton field is considered to study the s-wave scattering of fermion by a back ground dilaton black hole. It is found that the scattering process of chiral fermion does not violate unitarity and information remains preserved. Faddevian anomaly plays a crucial role on the information scenario.

  5. Quantum Effects for the Dirac Field in Reissner-Nordstrom-AdS Black Hole Background

    E-Print Network [OSTI]

    F. Belgiorno; S. L. Cacciatori

    2007-10-10

    The behavior of a charged massive Dirac field on a Reissner-Nordstrom-AdS black hole background is investigated. The essential self-adjointness of the Dirac Hamiltonian is studied. Then, an analysis of the discharge problem is carried out in analogy with the standard Reissner-Nordstrom black hole case.

  6. Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments

    E-Print Network [OSTI]

    R. A. Johnson; T. H. Burritt; S. R. Elliott; V. M. Gehman; V. E. Guiseppe; J. F. Wilkerson

    2011-12-30

    The Majorana Experiment will use arrays of enriched HPGe detectors to search for the neutrinoless double-beta decay of 76Ge. Such a decay, if found, would show lepton-number violation and confirm the Majorana nature of the neutrino. Searches for such rare events are hindered by obscuring backgrounds which must be understood and mitigated as much as possible. A potentially important background contribution to this and other double-beta decay experiments could come from decays of alpha-emitting isotopes in the 232Th and 238U decay chains on or near the surfaces of the detectors. An alpha particle emitted external to an HPGe crystal can lose energy before entering the active region of the detector, either in some external-bulk material or within the dead region of the crystal. The measured energy of the event will only correspond to a partial amount of the total kinetic energy of the alpha and might obscure the signal from neutrinoless double-beta decay. A test stand was built and measurements were performed to quantitatively assess this background. We present results from these measurements and compare them to simulations using Geant4. These results are then used to measure the alpha backgrounds in an underground detector in situ. We also make estimates of surface contamination tolerances for double-beta decay experiments using solid-state detectors.

  7. Cosmogenic Production as a Background in Searching for Rare Physics Processes

    E-Print Network [OSTI]

    D. -M. Mei; Z. -B. Yin; S. R. Elliott

    2009-03-12

    We revisit calculations of the cosmogenic production rates for several long-lived isotopes that are potential sources of background in searching for rare physics processes such as the detection of dark matter and neutrinoless double-beta decay. Using updated cosmic-ray neutron flux measurements, we use TALYS 1.0 to investigate the cosmogenic activation of stable isotopes of several detector targets and find that the cosmogenic isotopes produced inside the target materials and cryostat can result in large backgrounds for dark matter searches and neutrinoless double-beta decay. We use previously published low-background HPGe data to constrain the production of $^{3}H$ on the surface and the upper limit is consistent with our calculation. We note that cosmogenic production of several isotopes in various targets can generate potential backgrounds for dark matter detection and neutrinoless double-beta decay with a massive detector, thus great care should be taken to limit and/or deal with the cosmogenic activation of the targets.

  8. Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments

    SciTech Connect (OSTI)

    Johnson, R. A. [University of Washington, Seattle; Burritt, T. H. [University of Washington, Seattle; Elliott, S. R. [Los Alamos National Laboratory (LANL); Gehman, V. M. [Los Alamos National Laboratory (LANL); Guiseppe, V.E. [University of South Dakota; Wilkerson, J. F. [UNC/Triangle Univ. Nucl. Lab, Durham, NC/ORNL

    2012-01-01

    The Majorana Experiment will use arrays of enriched HPGe detectors to search for the neutrinoless double-beta decay of 76Ge. Such a decay, if found, would show lepton-number violation and confirm the Majorana nature of the neutrino. Searches for such rare events are hindered by obscuring backgrounds which must be understood and mitigated as much as possible. A potentially important background contribution to this and other double-beta decay experiments could come from decays of alpha-emitting isotopes in the 232Th and 238U decay chains on or near the surfaces of the detectors. An alpha particle emitted external to an HPGe crystal can lose energy before entering the active region of the detector, either in some external-bulk material or within the dead region of the crystal. The measured energy of the event will only correspond to a partial amount of the total kinetic energy of the alpha and might obscure the signal from neutrinoless double-beta decay. A test stand was built and measurements were performed to quantitatively assess this background. We present results from these measurements and compare them to simulations using Geant4. These results are then used to measure the alpha backgrounds in an underground detector in situ. We also make estimates of surface contamination tolerances for double-beta decay experiments using solid-state detectors.

  9. Astroparticle physics with a customized low-background broad energy Germanium detector

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Amman, M.; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Barbeau, P. S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Busch, Matthew; Capps, Greg L.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Diaz, J.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fujikawa, Brian; Fuller, Erin S.; Gehman, Victor M.; Giovanetti, G. K.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Harper, Gregory; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Hossbach, Todd W.; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Miley, Harry S.; Miller, M. L.; Mizouni, Leila; Myers, Allan W.; Nomachi, Masaharu; Orrell, John L.; Peterson, David; Phillips, D.; Poon, Alan; Prior, Gersende; Qian, J.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Rykaczewski, Krzysztof P.; Salazar, Harold; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Steele, David; Strain, J.; Swift, Gary; Thomas, K.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Wilkerson, J. F.; Wolfe, B. A.; Xiang, W.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.; Zimmerman, S.

    2011-10-01

    The Majorana Collaboration is building the Majorana Demonstrator, a 60 kg array of high purity germanium detectors housed in an ultra-low background shield at the Sanford Underground Laboratory in Lead, SD. The Majorana Demonstrator will search for neutrinoless double-beta decay of 76Ge while demonstrating the feasibility of a tonne-scale experiment. It may also carry out a dark matter search in the 1-10 GeV/c² mass range. We have found that customized Broad Energy Germanium (BEGe) detectors produced by Canberra have several desirable features for a neutrinoless double-beta decay experiment, including low electronic noise, excellent pulse shape analysis capabilities, and simple fabrication. We have deployed a customized BEGe, the Majorana Low-Background BEGe at Kimballton (MALBEK), in a low-background cryostat and shield at the Kimballton Underground Research Facility in Virginia. This paper will focus on the detector characteristics and measurements that can be performed with such a radiation detector in a low-background environment.

  10. Introductive Backgrounds of Modern Quantum Mathematics with Application to Nonlinear Dynamical Systems

    E-Print Network [OSTI]

    Anatoliy K. Prykarpatsky; Nikolai N. Bogolubov; Jolanta Golenia; Ufuk Taneri

    2009-02-25

    Introductive backgrounds of a new mathematical physics discipline - Quantum Mathematics - are discussed and analyzed both from historical and analytical points of view. The magic properties of the second quantization method, invented by V. Fock in 1932, are demonstrated, and an impressive application to the nonlinear dynamical systems theory is considered.

  11. Josh is a pragmatic guy. He knows that a strong background in geology and environmental

    E-Print Network [OSTI]

    Kunkle, Tom

    Josh is a pragmatic guy. He knows that a strong background in geology and environmental geosciences will help him excel in the energy sector. So, as a freshman, he took the intro to geology course. "My fit. "As a geology major, I have to get out in the field to really apply what I've learned in class

  12. The role of uPAR signaling in lung cancer Background and significance

    E-Print Network [OSTI]

    Gleeson, Joseph G.

    The role of uPAR signaling in lung cancer Background and significance Lung cancer is the leading of lung cancer ­ non-small-cell-lung cancer (about 85% of all lung cancer cases) and small- cell-lung cancer (about 15%) (Herbst et al., 2008). Small cell lung carcinoma (SCLC) is rapidly growing and often

  13. The population in the background of open clusters: Tracer of the Norma-Cygnus arm

    E-Print Network [OSTI]

    A. K. Pandey; S. Sharma; K. Ogura

    2006-08-31

    We present colour-magnitude diagrams of open clusters, located in the range $112^\\circ arm and may be the part of Norma-Cygnus (outer) arm. The outer arm seems to be continued from $l\\sim120^\\circ$ to $l\\sim235^\\circ$. The background populations follow the downward warp of the Galactic plane around $l\\sim240^\\circ$.

  14. HOW TO: Complete Form I-9 Verification for Off-Site Employees 1 Background info

    E-Print Network [OSTI]

    HOW TO: Complete Form I-9 Verification for Off-Site Employees 1 Background info: By law, the university must have a valid Form I-9 on file for employees. The Form I-9 form must be completed within 3 location to complete their Form I-9 ­ Employment Eligibility Verification. The form has three parts

  15. II UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE 1. History and Background

    E-Print Network [OSTI]

    Boynton, Walter R.

    of Maryland Center for Environmental Science (UMCES) is a research, education, and service institution delivers its services through environmental science education programs for K-12 students and teachers FOR ENVIRONMENTAL SCIENCE 1. History and Background 1.1 UMCES Overview 1.2 UMCES Locations: History

  16. Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Robert A. Johnson Chair of the Supervisory Committee: Professor John F. Wilkerson Physics The observation of neutrinoless double-beta decay

  17. 5.0 Application of Chemical Reaction Codes 5.1. Background

    E-Print Network [OSTI]

    5.1 5.0 Application of Chemical Reaction Codes 5.1. Background Determination of species analyses of water compositions and a competent chemical reaction model. Computerized chemical reaction that may leach from waste, an understanding of the capabilities and application of chemical reaction models

  18. Can Solar Neutrinos be a Serious Background in Direct Dark Matter Searches?

    E-Print Network [OSTI]

    J. D. Vergados; H. Ejiri

    2008-05-30

    The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current is examined considering the boron solar neutrinos. These neutrinos could potentially become a source of background in the future dark matter searches aiming at nucleon cross sections in the region well below the few events per ton per year.

  19. Kernel Level Energy-Efficient 3G Background Traffic Shaper for Android Smartphones

    E-Print Network [OSTI]

    Kernel Level Energy-Efficient 3G Background Traffic Shaper for Android Smartphones Ekhiotz Jon the Android platform, and measures its energy footprint. The total energy savings of our implementation range study. Index Terms--transmission energy; 3G; kernel; Android I. INTRODUCTION Mobile users have been

  20. Linear Theory Calculations for the Sea Breeze in a Background Wind: The Equatorial Case

    E-Print Network [OSTI]

    Linear Theory Calculations for the Sea Breeze in a Background Wind: The Equatorial Case TINGTING- terpreted by comparing to the U 5 0 theory of Rotunno. For U 6¼ 0 the Fourier integral solution consists quadrature method. 1. Introduction The sea breeze circulation is an atmospheric response to differential

  1. Internet Governance, National Interest and International Relations Background Paper for the

    E-Print Network [OSTI]

    Schweik, Charles M.

    Internet Governance, National Interest and International Relations Background Paper for the United associated together. When one considers the Internet and foreign affairs, it is usually viewed in terms? This is currently done by ICANN, the Internet Corporation for Assigned Names and Numbers. It was created by the US

  2. Linear Theory Calculations for the Sea Breeze in a Background Wind: The Equatorial Case

    E-Print Network [OSTI]

    in a Background Wind: The Equatorial Case Tingting Qian, Craig C. Epifanio and Fuqing Zhang Texas A&M University.....not really.) Prototype problem: linear wave generation due to diurnally oscillating heat source over land (Mapes et al. 2003) landsea (and not the sea-breeze density current) constant wind & stability #12

  3. Technical background information for the environmental and safety report, Volume 4: White Oak Lake and Dam

    SciTech Connect (OSTI)

    Oakes, T.W.; Kelly, B.A.; Ohnesorge, W.F.; Eldridge, J.S.; Bird, J.C.; Shank, K.E.; Tsakeres, F.S.

    1982-03-01

    This report has been prepared to provide background information on White Oak Lake for the Oak Ridge National Laboratory Environmental and Safety Report. The paper presents the history of White Oak Dam and Lake and describes the hydrological conditions of the White Oak Creek watershed. Past and present sediment and water data are included; pathway analyses are described in detail.

  4. Formaldehyde columns from the Ozone Monitoring Instrument: Urban versus background levels and evaluation using aircraft

    E-Print Network [OSTI]

    Mlllet, Dylan B.

    Formaldehyde columns from the Ozone Monitoring Instrument: Urban versus background levels formaldehyde column (WHCHO) retrievals from the Ozone Monitoring Instrument (OMI) and assess the information (20­200 km) near many urban areas. Citation: Boeke, N. L., et al. (2011), Formaldehyde columns from

  5. Policy Review Process and Background The University Advisory Council subcommittee on Consensual Relations was chaired by

    E-Print Network [OSTI]

    Hickey, Timothy J.

    Policy Review Process and Background The University Advisory Council subcommittee on Consensual by the UAC with reviewing the consensual relationship policies of our peer institutions and drafting a policy for Brandeis faculty and staff in keeping with our values and traditions. After reviewing policies from public

  6. Background: Subsurface Water Retention Technology (SWRT) Durable and easy to install: Water

    E-Print Network [OSTI]

    Background: Subsurface Water Retention Technology (SWRT) Benefits Durable and easy to install: Water retaining membranes can last at least 40 years and can be installed quickly and costeffectively permeable marginal soils converting them to much higher production levels of food crops. Better water

  7. Project plan for the background soils project for the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    SciTech Connect (OSTI)

    NONE

    1995-09-01

    The Background Soils Project for the Paducah Gaseous Diffusion Plant (BSPP) will determine the background concentration levels of selected naturally occurring metals, other inorganics, and radionuclides in soils from uncontaminated areas in proximity to the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The data will be used for comparison with characterization and compliance data for soils, with significant differences being indicative of contamination. All data collected as part of this project will be in addition to other background databases established for the PGDP. The BSPP will address the variability of surface and near-surface concentration levels with respect to (1) soil taxonomical types (series) and (2) soil sampling depths within a specific soil profile. The BSPP will also address the variability of concentration levels in deeper geologic formations by collecting samples of geologic materials. The BSPP will establish a database, with recommendations on how to use the data for contaminated site assessment, and provide data to estimate the potential human and health and ecological risk associated with background level concentrations of potentially hazardous constituents. BSPP data will be used or applied as follows.

  8. LLAMA: An Adaptive Strategy for Performing Background Tasks on Mobile Denitsa Tilkidjieva, Nilanjan Banerjee

    E-Print Network [OSTI]

    Rollins, Sami

    LLAMA: An Adaptive Strategy for Performing Background Tasks on Mobile Devices Denitsa Tilkidjieva that are always connected to a network and power supply, but it is not suitable for mobile devices that meet neither property. When they are not actively used, mobile devices often go into a power-saving state

  9. Review of Electricity and It is useful to recall the background of Maxwell's Equations. We consider

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    Chapter 2 Review of Electricity and Magnetism It is useful to recall the background of Maxwell to consider induced electric dipoles. In non-polar materials, in the linear regime, the average dipole moment polarizability. The electric polarization P =Np =oNMOL e E is the dipole moment per volume, N is the number

  10. DC WRRC Report No. 103 Background Study of the Ground Water in

    E-Print Network [OSTI]

    District of Columbia, University of the

    Leaching 51 5.0. FILLINGS 51 5.1 Background Infonnation 51 5.2 Special Research Needs 54 6.0. CONCLUSION. Area showing the General latitude and longitude. Figure 2. Fall line in the Middle Atlantic Region. Figure 3. Geologic section across the District of Columbia area, showing the succession and general

  11. The Nature of the Ionising Background at z=2.5-5

    E-Print Network [OSTI]

    Aaron Sokasian; Tom Abel; Lars E. Hernquist

    2002-06-25

    Using radiative transfer calculations and cosmological simulations of structure formation, we study constraints that can be placed on the nature of the cosmic ultraviolet (UV) background in the redshift interval 2.5< z <5. Our approach makes use of observational estimates of the opacities of hydrogen and singly ionised helium in the intergalactic medium during this epoch. In particular, we model the reionisation of He II by sources of hard ultraviolet radiation, i.e. quasars, and infer values for our parameterisation of this population from observational estimates of the opacity of the He II Lyman-alpha forest. Next, we estimate the photoionisation rate of H I from these sources and find that their contribution to the ionising background is insufficient to account for the measured opacity of the H I Lyman-alpha forest at a redshift z 3. This motivates us to include a soft, stellar component to the ionising background to boost the hydrogen photoionisation rate, but which has a negligible impact on the He II opacity. In order to simultaneously match observational estimates of the H I and He II opacities, we find that galaxies and quasars must contribute about equally to the ionising background in H I at z~ 3.

  12. Indirect Costs of Research Background Information Prepared by the Research Services Office

    E-Print Network [OSTI]

    Wang, Hao "Howard"

    Indirect Costs of Research Background Information Prepared by the Research Services Office of indirect costs at the University of Alberta (moving to 85% to the Faculty (ie, Dean) and 15% to Central the importance of including indirect costs in research funding applications. The costs of doing research may

  13. 1 Background and Motivation Today, services based on web technology are a hot

    E-Print Network [OSTI]

    van der Mei, Rob

    1 Background and Motivation Today, services based on web technology are a hot topic and popularity of e-commerce is growing. The increasing role of web technology is particularly strong in business that the maturity level of web browsing performance is still low, or at least unstable. In current practise, popular

  14. Multimeson production in pp interactions as a background for eta and eta' decays

    E-Print Network [OSTI]

    A. Kup??; P. Moskal; M. Zieli?ski

    2008-03-18

    Multimeson production in pp interactions comprises important background for eta, omega and eta' mesons production experiments and for the studies of their decays planned with WASA detector at COSY. The available information about the reactions is summarized and the need for efforts to describe the processes is stressed.

  15. On the anisotropy of the gravitational wave background from massless preheating

    SciTech Connect (OSTI)

    Bethke, Laura; Rajantie, Arttu [Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2AZ (United Kingdom); Figueroa, Daniel G., E-mail: laura.bethke06@imperial.ac.uk, E-mail: daniel.figueroa@unige.ch, E-mail: a.rajantie@imperial.ac.uk [Département de Physique Théorique and Center for Astroparticle Physics, Université de Genève, 24 quai Ernest Ansermet, CH–1211 Genève 4 (Switzerland)

    2014-06-01

    When a light scalar field is present during inflation, its value varies on superhorizon scales, modulating the preheating process at the end of inflation. Consequently, the amplitude of the gravitational wave (GW) background produced during preheating is also modulated. The observed energy density of this background appears therefore anisotropic at different angles in the sky. We provide a master formula for the angular power spectrum C{sub l} of the anisotropies in the GW background from preheating, valid for any scenario where the anisotropies are due to the superhorizon modulation of a light degree of freedom. Using lattice field theory simulations of massless preheating with g{sup 2}/? = 2, we find a flat angular spectrum l(l+1)C{sub l} ? 3 × 10{sup ?4}, which represents a strong anisotropy of ? 1% variations on large angular scales. For our choice of couplings, long wavelengths are amplified most strongly during parametric resonance, which is crucial for the development of the anisotropies. If future direct detection GW observatories are capable of detecting backgrounds of cosmological origin, they (may also) be able to detect this effect. This could eventually become a powerful tool to discriminate among inflationary and preheating scenarios.

  16. Estimation of Cosmic Induced Contamination in Ultra-low Background Detector Materials

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Berguson, Timothy J.; Greene, Austen T.

    2012-08-01

    Executive Summary This document presents the result of investigating a way to reliably determine cosmic induced backgrounds for ultra-low background materials. In particular, it focuses on those radioisotopes produced by the interactions with cosmic ray particles in the detector materials that act as a background for experiments looking for neutrinoless double beta decay. This investigation is motivated by the desire to determine background contributions from cosmic ray activation of the electroformed copper that is being used in the construction of the MAJORANA DEMONSTRATOR. The most important radioisotope produced in copper that contributes to the background budget is 60Co, which has the potential to deposit energy in the region of interest of this experiment. Cobalt-60 is produced via cosmic ray neutron collisions in the copper. This investigation aims to provide a method for determining whether or not the copper has been exposed to cosmic radiation beyond the threshold which the Majorana Project has established as the maximum exposure. This threshold is set by the Project as the expected contribution of this source of background to the overall background budget. One way to estimate cosmic ray neutron exposure of materials on the surface of the Earth is to relate it to the cosmic ray muon exposure. Muons are minimum-ionizing particles and the available technologies to detect muons are easier to implement than those to detect neutrons. We present the results of using a portable, ruggedized muon detector, the µ-Witness made by our research group, for determination of muon exposure of materials for the MAJORANA DEMONSTRATOR. From the muon flux measurement, this report presents a method to estimate equivalent sea-level exposure, and then infer the neutron exposure of the tracked material and thus the cosmogenic activation of the copper. This report combines measurements of the muon flux taken by the µ-Witness detector with Geant4 simulations in order to assure our understanding of the µ-Witness prototype. As a proof of concept, we present the results of using this detector with electroformed copper during its transport from Pacific Northwest National Laboratory, where the copper is grown, to the underground lab in Lead, South Dakota, where the experiment is being deployed. The development of a code to be used with the Majorana parts tracking database, designed to aid in estimating the cosmogenic activation, is also presented.

  17. What can BeppoSAX do about the 2-10 keV cosmic background ? A progress report

    E-Print Network [OSTI]

    L. Chiappetti; G. Cusumano; S. Del Sordo; M. C. Maccarone; T. Mineo; S. Molendi

    1997-12-18

    We report the current status of the analysis of the MECS background using the entire dataset of the BeppoSAX Science performance Verification Phase. We have collected 360 ks of dark Earth instrumental background, 470 ks of bright Earth background and 1100 ks of blank field data. We are attempting to model the instrumental background in terms of its various components (in particular the spatial modulation of the residual contamination by the built-in Fe calibration sources), and then use this model, and the information on the vignetting and the PSF to derive the cosmic background in the 2-10 keV range

  18. Axion decay and anisotropy of near-IR extragalactic background light

    E-Print Network [OSTI]

    Yan Gong; Asantha Cooray; Ketron Mitchell-Wynne; Xuelei Chen; Michael Zemcov; Joseph Smidt

    2015-11-05

    The extragalactic background light is expected to be comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of radiation. An example is the intra-halo light, associated with diffuse stars in dark matter halos resulting from galaxy mergers and tidal interactions, identified based on measurements involving the angular power spectrum of infrared background anisotropies. The angular power spectra of the near-infrared intensities could still contain additional signals and a complete understanding of the nature of the IR background is still lacking in the literature. Here we explore the constraints that can be placed on the decay products associated with particle decays, especially candidate dark matter models involving axions that trace dark matter halos of galaxies. Axions with a mass around a few eV will decay via two photons with wavelengths in the near-IR band, and will leave a signature in the IR background intensity power spectrum. Using recent power spectra measurements from the Hubble Space Telescope (HST) and Cosmic Infrared Background Experiment (CIBER), we find that the 0.6 to 1.6 micron power spectra can be explained with an axion mass of around 4 eV and a total axion abundance as a fractional energy density Omega_a~0.05. Such an abundance is comparable to the baryon density of the Universe. The absolute EBL intensity of axion decay photons is slightly below 1 nW m^-2 sr^-1 at near-IR wavelengths, roughly a factor of 10 to 20 below the total integrated light from galaxies. The suggested axion mass and abundance are not ruled out by existing cosmological observations.

  19. White-dwarf-white-dwarf galactic background in the LISA data

    SciTech Connect (OSTI)

    Edlund, Jeffrey A.; Tinto, Massimo; Krolak, Andrzej; Nelemans, Gijs [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States); Max-Planck-Institute for Gravitational Physics, Albert Einstein Institute, D-14476 Golm (Germany); Department of Astrophysics, IMAPP, Radboud University Nijmegen (Netherlands)

    2005-06-15

    LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy.

  20. Simulation of background from low-level tritium and radon emanation in the KATRIN spectrometers

    SciTech Connect (OSTI)

    Leiber, B. [Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)] [Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); Collaboration: KATRIN Collaboration

    2013-08-08

    The KArlsruhe TRItium Neutrino (KATRIN) experiment is a large-scale experiment for the model independent determination of the mass of electron anti-neutrinos with a sensitivity of 200 meV/c{sup 2}. It investigates the kinematics of electrons from tritium beta decay close to the endpoint of the energy spectrum at 18.6 keV. To achieve a good signal to background ratio at the endpoint, a low background rate below 10{sup ?2} counts per second is required. The KATRIN setup thus consists of a high luminosity windowless gaseous tritium source (WGTS), a magnetic electron transport system with differential and cryogenic pumping for tritium retention, and electro-static retarding spectrometers (pre-spectrometer and main spectrometer) for energy analysis, followed by a segmented detector system for counting transmitted beta-electrons. A major source of background comes from magnetically trapped electrons in the main spectrometer (vacuum vessel: 1240 m{sup 3}, 10{sup ?11} mbar) produced by nuclear decays in the magnetic flux tube of the spectrometer. Major contributions are expected from short-lived radon isotopes and tritium. Primary electrons, originating from these decays, can be trapped for hours, until having lost almost all their energy through inelastic scattering on residual gas particles. Depending on the initial energy of the primary electron, up to hundreds of low energetic secondary electrons can be produced. Leaving the spectrometer, these electrons will contribute to the background rate. This contribution describes results from simulations for the various background sources. Decays of {sup 219}Rn, emanating from the main vacuum pump, and tritium from the WGTS that reaches the spectrometers are expected to account for most of the background. As a result of the radon alpha decay, electrons are emitted through various processes, such as shake-off, internal conversion and the Auger deexcitations. The corresponding simulations were done using the KASSIOPEIA framework, which has been developed for the KATRIN experiment for low-energy electron tracking, field calculation and detector simulation. The results of the simulations have been used to optimize the design parameters of the vacuum system with regard to radon emanation and tritium pumping, in order to reach the stringent requirements of the neutrino mass measurement.

  1. Origin of background electron concentration in InxGa1-xN alloys

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

    Pantha, B. N.; Wang, H.; Khan, N.; Lin, J. Y.; Jiang, H. X.

    2011-08-01

    The origin of high background electron concentration (n) in InxGa1-xN alloys has been investigated. A shallow donor was identified as having an energy level (ED1) that decreases with x (ED1 = 16 meV at x = 0 and ED1 = 0 eV at x ~ 0.5) and that crossover the conduction band at x ~ 0.5. This shallow donor is believed to be the most probable cause of high n in InGaN. This understanding is consistent with the fact that n increases sharply with an increase in x and becomes constant for x > 0.5. A continuous reduction in nmore »was obtained by increasing the V/III ratio during the epilayer growth, suggesting that nitrogen vacancy-related impurities are a potential cause of the shallow donors and high background electron concentration in InGaN« less

  2. Partially twisted superconformal M5 brane in R-symmetry gauge field backgrounds

    E-Print Network [OSTI]

    Bak, Dongsu

    2015-01-01

    We obtain the action for a curved superconformal abelian M5 brane with the background R-symmetry gauge field turned on. We then restrict ourselves to superconformal M5 brane on a sphere times flat Minkowski space. We choose R-symmetry SO(1,4) instead of SO(5), which enables us to partially twist on Minkowski space and replace it by some curved Lorentzian manifold. We obtain M5 brane actions on $M_{1,1} \\times S^4$ and $M_{1,2} \\times S^3$ where actions and all fields, including the background gauge field, are real. Dimensional reduction along time gives real 5d SYM actions with nonabelian generalizations.

  3. A low background facility inside the LVD detector at Gran Sasso

    E-Print Network [OSTI]

    Arneodo, F

    2008-01-01

    The Large Volume Detector (LVD) in the Gran Sasso Laboratory of INFN is an observatory mainly devoted to search for neutrinos from core collapse supernovae. It consists of 1000 tons of liquid scintillator divided in 840 stainless steel tanks 1.5m$^3$ each. In this letter we present the possibility for LVD to work both as a passive shield and moderator for the low energy gamma and neutron background and as an active veto for muons and higher energy neutrons. An inner region inside the LVD structure ("LVD Core Facility") can be identified, with a volume of about 30m$^3$, with the neutron background typical of an underground laboratory placed at a much deeper site. This region can be realized with a negligible impact on the LVD operation and sensitive mass. The LVD Core Facility could be effectively exploited by a compact experiment for the search of rare events, such as double beta decay or dark matter.

  4. Empirical Correction of Crosstalk in a Low-Background Germanium ?–? Analysis System

    SciTech Connect (OSTI)

    Keillor, Martin E.; Erikson, Luke E.; Aalseth, Craig E.; Day, Anthony R.; Fuller, Erin S.; Glasgow, Brian D.; Hoppe, Eric W.; Hossbach, Todd W.; Mizouni, Leila K.; Myers, Allan W.; Overman, Cory T.; Seifert, Allen; Stavenger, Timothy J.

    2013-05-01

    ABSTRACT The Pacific Northwest National Laboratory is currently developing a custom software suite capable of automating many of the tasks required to accurately analyze coincident signals within gamma spectrometer arrays. During the course of this work, significant crosstalk was identified in the energy determination for spectra collected with a new low-background intrinsic germanium (HPGe) array at PNNL. The HPGe array is designed for high detection efficiency, ultra-low-background performance, and sensitive gamma gamma coincidence detection. The first half of the array, a single cryostat containing 7 HPGe crystals, was recently installed into a new shallow underground laboratory facility. This update will present a brief review of the germanium array, describe the observed crosstalk, and present a straight-forward empirical correction that significantly reduces the impact of this crosstalk on the spectroscopic performance of the system.

  5. MaGe - a Geant4-based Monte Carlo framework for low-background experiments

    E-Print Network [OSTI]

    Yuen-Dat Chan; Jason A. Detwiler; Reyco Henning; Victor M. Gehman; Rob A. Johnson; David V. Jordan; Kareem Kazkaz; Markus Knapp; Kevin Kroninger; Daniel Lenz; Jing Liu; Xiang Liu; Michael G. Marino; Akbar Mokhtarani; Luciano Pandola; Alexis G. Schubert; Claudia Tomei

    2008-02-06

    A Monte Carlo framework, MaGe, has been developed based on the Geant4 simulation toolkit. Its purpose is to simulate physics processes in low-energy and low-background radiation detectors, specifically for the Majorana and Gerda $^{76}$Ge neutrinoless double-beta decay experiments. This jointly-developed tool is also used to verify the simulation of physics processes relevant to other low-background experiments in Geant4. The MaGe framework contains simulations of prototype experiments and test stands, and is easily extended to incorporate new geometries and configurations while still using the same verified physics processes, tunings, and code framework. This reduces duplication of efforts and improves the robustness of and confidence in the simulation output.

  6. Neutron Inelastic Scattering Processes as Background for Double-Beta Decay Experiments

    E-Print Network [OSTI]

    D. -M. Mei; S. R. Elliott; A. Hime; V. Gehman; K. Kazkaz

    2008-01-26

    We investigate several Pb$(n,n'\\gamma$) and Ge$(n,n'\\gamma$) reactions. We measure $\\gamma$-ray production from Pb$(n,n'\\gamma$) reactions that can be a significant background for double-beta decay experiments which use lead as a massive inner shield. Particularly worrisome for Ge-based double-beta decay experiments are the 2041-keV and 3062-keV $\\gamma$ rays produced via Pb$(n,n'\\gamma$). The former is very close to the ^{76}Ge double-beta decay endpoint energy and the latter has a double escape peak energy near the endpoint. Excitation $\\gamma$-ray lines from Ge$(n,n'\\gamma$) reactions are also observed. We consider the contribution of such backgrounds and their impact on the sensitivity of next-generation searches for neutrinoless double-beta decay using enriched germanium detectors.

  7. Spatial Cross Spectrum: Reducing Incoherent Convective Background of Resolved Heloseismic Instruments

    E-Print Network [OSTI]

    R. A. Garcia; S. Mathur; I. Gonzalez Hernandez; A. Jimenez

    2008-10-09

    Measurements of low-order p modes and gravity modes are perturbed by the solar convective background. Such perturbation increases below 2mHz for intensity measurements and 1mHz for velocity measurements. While the low-degree modes have large spatial scales, the convective motions have much smaller spatial distribution. In this work, we take advantage of these different scale sizes to explore the use of spatial cross spectrum between different regions of the Sun. The aim is to reduce the incoherent background noise and, therefore, increase the signal-to-noise ratio of the signals that are coherent across the full disk. To do so we use the VIRGO/LOI instrument aboard SoHO and the GONG ground-based network to study the intensity and velocity spatial cross spectra.

  8. A background correction algorithm for Van Allen Probes MagEIS electron flux measurements

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

    Claudepierre, S. G.; O'Brien, T. P.; Blake, J. B.; Fennell, J. F.; Roeder, J. L.; Clemmons, J. H.; Looper, M. D.; Mazur, J. E.; Mulligan, T. M.; Spence, H. E.; et al

    2015-07-14

    We describe an automated computer algorithm designed to remove background contamination from the Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS) electron flux measurements. We provide a detailed description of the algorithm with illustrative examples from on-orbit data. We find two primary sources of background contamination in the MagEIS electron data: inner zone protons and bremsstrahlung X-rays generated by energetic electrons interacting with the spacecraft material. Bremsstrahlung X-rays primarily produce contamination in the lower energy MagEIS electron channels (~30–500 keV) and in regions of geospace where multi-M eV electrons are present. Inner zone protons produce contamination in all MagEIS energymore »channels at roughly L « less

  9. Non-thermal Cosmic Backgrounds and prospects for future high-energy observations of blazars

    E-Print Network [OSTI]

    P. Giommi; S. Colafrancesco

    2006-02-10

    We discuss the contribution of the blazar population to the extragalactic background radiation across the electromagnetic (e.m.) spectrum with particular reference to the microwave, hard-X-ray and gamma-ray bands. Our estimates are based on a recently derived blazar radio LogN-LogS that was built by combining several radio and multi-frequency surveys. We show that blazar emission integrated over cosmic time gives rise to a considerable broad-band non-thermal cosmic background that dominates the extragalactic brightness in the high-energy part of the e.m. spectrum. We also estimate the number of blazars that are expected to be detected by future planned or hypothetical missions operating in the X-ray and gamma-ray energy bands.

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

    E-Print Network [OSTI]

    Tomonori Totani

    1999-04-13

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

  11. Apparatus having reduced background for measuring radiation activity in aerosol particles

    DOE Patents [OSTI]

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

    1992-01-01

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

  12. What Can the Cosmic Microwave Background Tell Us About the Outer Solar System?

    E-Print Network [OSTI]

    Daniel Babich; Cullen H. Blake; Charles Steinhardt

    2007-05-07

    We discuss two new observational techniques that use observations of the Cosmic Microwave Background (CMB) to place constraints upon the mass, distance, and size distribution of small objects in the Kuiper Belt and inner Oort Cloud, collectively known as Trans-Neptunian Objects (TNOs). The first new technique considers the spectral distortion of the isotropic, or monopole, CMB by TNOs that have been heated by solar radiation to temperatures above that of the CMB. We apply this technique to the spectral measurements of the CMB by the Far Infrared Absolute Spectrophotometer (FIRAS) on the Cosmic Background Explorer (COBE). The second technique utilizes the change in amplitude of the TNO signal due to the orbital motion of the observer to separate the TNO signal from the invariant extra-galactic CMB and construct a map of the mass distribution in the outer Solar System. We estimate the ability of future CMB experiments to create such a map.

  13. Harmonic oscillator in a background magnetic field in noncommutative quantum phase-space

    E-Print Network [OSTI]

    Joseph Ben Geloun; Sunandan Gangopadhyay; Frederik G Scholtz

    2009-01-22

    We solve explicitly the two-dimensional harmonic oscillator and the harmonic oscillator in a background magnetic field in noncommutative phase-space without making use of any type of representation. A key observation that we make is that for a specific choice of the noncommutative parameters, the time reversal symmetry of the systems get restored since the energy spectrum becomes degenerate. This is in contrast to the noncommutative configuration space where the time reversal symmetry of the harmonic oscillator is always broken.

  14. A NEW CALCULATION OF THE IONIZING BACKGROUND SPECTRUM AND THE EFFECTS OF He II REIONIZATION

    SciTech Connect (OSTI)

    Faucher-Giguere, Claude-Andre; Lidz, Adam; Zaldarriaga, Matias; Hernquist, Lars, E-mail: cgiguere@cfa.harvard.ed [Department of Astronomy, Harvard University, Cambridge, MA 02138 (United States)

    2009-10-01

    The ionizing background determines the ionization balance and the thermodynamics of the cosmic gas. It is therefore a fundamental ingredient to theoretical and empirical studies of both the intergalactic medium (IGM) and galaxy formation. We present here a new calculation of its spectrum that satisfies the empirical constraints we recently obtained by combining state-of-the-art luminosity functions and intergalactic opacity measurements. In our preferred model, star-forming galaxies and quasars each contribute substantially to the H I ionizing field at z < 3, with galaxies rapidly overtaking quasars at higher redshifts as quasars become rarer. In addition to our fiducial model, we explore the physical dependences of the calculated background and clarify how recombination emission contributes to the ionization rates. We find that recombinations do not simply boost the ionization rates by the number of re-emitted ionizing photons as many of these rapidly redshift below the ionization edges and have a distribution of energies. A simple analytic model that captures the main effects seen in our numerical radiative transfer calculations is given. Finally, we discuss the effects of He II reionization by quasars on both the spectrum of the ionizing background and on the thermal history of the IGM. In regions that have yet to be reionized, the spectrum is expected to be almost completely suppressed immediately above 54.4 eV, while a background of higher energy ({approx}>0.5 keV) photons permeates the entire universe owing to the frequency dependence of the photoionization cross section. We provide an analytical model of the heat input during He II reionization and its effects on the temperature-density relation.

  15. New acceptor centers of the background impurities in p-CdZnTe

    SciTech Connect (OSTI)

    Plyatsko, S. V. Rashkovetskyi, L. V.

    2013-07-15

    Low-temperature photoluminescence data are used to study the redistribution of the background impurities and host components of p-CdZnTe single crystals with a resistivity of 1-50 {Omega} cm upon their interaction with infrared laser radiation. The effect of widening of the band gap and the formation of new acceptor centers in response to laser-stimulated changes in the system of intrinsic defects are established. The activation energy of the new acceptor centers is determined.

  16. A novel approach to background reduction in double beta decay experiments

    E-Print Network [OSTI]

    T. Tabarelli de Fatis

    2009-08-02

    Active background reduction in high resolution calorimeters is a promising approach to achieve ultimate sensitivity in neutrinoless double beta decay experiments. We propose Cerenkov emission from beta rays in bolometric crystals as a viable alternative to scintillation. This novel approach could broaden the range of materials of interest for calorimetric searches of the double beta decay. We discuss the optical properties of TeO$_2$ crystals, as a show case.

  17. Quality Assessment of Feeder Cattle and Processes Based on Available Background Information 

    E-Print Network [OSTI]

    Franke, Jake

    2013-01-18

    . These results indicate beef cattle producers must manage cows and calves to facilitate effective passive transfer of immunity. Similarly, Zimmerman et al. (2006) reported that a single dose of a modified live vaccine containing BVDV administered to calves...-1 QUALITY ASSESSMENT OF FEEDER CATTLE AND PROCESSES BASED ON AVAILABLE BACKGROUND INFORMATION A Dissertation by JAKE ANDREW FRANKE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

  18. Identification and summary characterization of materials potentially requiring vitrification: Background information

    SciTech Connect (OSTI)

    Croff, A.G.

    1996-05-13

    This document contains background information for the Workshop in general and the presentation entitled `Identification and Summary Characterization of Materials Potentially Requiring Vitrification` that was given during the first morning of the workshop. summary characteristics of 9 categories of US materials having some potential to be vitrified are given. This is followed by a 1-2 page elaborations for each of these 9 categories. References to more detailed information are included.

  19. Accounting for the Unresolved X-ray Background with Sterile Neutrino Dark Matter

    E-Print Network [OSTI]

    Daniel Cumberbatch; Joseph Silk

    2007-09-03

    We consider a scenario where keV sterile neutrinos constitute all of the currently inferred dark matter abundance, whose radiative decays could potentially account for the flux contributions to the X-ray background attributed to unresolved sources. Here we apply integrated flux methods to results from the observations of the North and South Chandra deep fields in order to deduce constraints on the sterile neutrino mass-mixing parameters.

  20. Three-dimensional Background Field Gravity: A Hamilton-Jacobi analysis

    E-Print Network [OSTI]

    N. T. Maia; B. M. Pimentel; C. E. Valcárcel

    2015-03-14

    We analyse the constraint structure of the Background Field model for three dimensional gravity including a cosmological term via the Hamilton-Jacobi formalism. We find the complete set of involutive Hamiltonians that assures the integrability of the system and calculate the characteristic equations of the system. We established the equivalence between these equations and the field equations and also obtain the generators of canonical and gauge transformations.

  1. Small-scale primordial magnetic fields and anisotropies in the cosmic microwave background radiation

    SciTech Connect (OSTI)

    Jedamzik, Karsten [Laboratoire de Univers et Particules, UMR5299-CNRS, Université de Montpellier II, F-34095 Montpellier (France); Abel, Tom, E-mail: karsten.jedamzik@um2.fr, E-mail: tabel@slac.stanford.edu [Kavli Institute for Particle Astrophysics and Cosmology, SLAC/Stanford University, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2013-10-01

    It is shown that small-scale magnetic fields present before recombination induce baryonic density inhomogeneities of appreciable magnitude. The presence of such inhomogeneities changes the ionization history of the Universe, which in turn decreases the angular scale of the Doppler peaks and increases Silk damping by photon diffusion. This unique signature could be used to (dis)prove the existence of primordial magnetic fields of strength as small as B ? 10{sup ?11} Gauss by cosmic microwave background observations.

  2. Conditions for Debris-Background Ion Interactions and Collisionless Shock Wave Generation

    SciTech Connect (OSTI)

    Winske, Dan [Los Alamos National Laboratory; Cowee, Misa [Los Alamos National Laboratory

    2012-07-10

    We use hybrid simulations and simple theoretical arguments to determine when debris ions streaming relative to background ions in a collisionless, magnetized plasma couple strongly enough to generate a magnetosonic shock wave. We consider three types of configurations: one-dimensional, the two-dimensional extension of the 1-D case, and a more complex 2-D geometry that contains some effects that would be found in a laser-produced, laboratory plasma. We show that the simulation results as well as previous Russian and LLNL results reduce to a simple condition (R{sub m}/{rho}{sub d} = equal mass radius/debris ion gyroradius {ge} 0.7) for the generation of a shock wave. Strong debris interaction with the background is characterized by the formation of a magnetic pulse that steepens and speeds up as it encounters the debris ions deflected by the magnetic field. The pulse further evolves into a shock. As the earlier work has indicated, the process also involves the generation of a transverse electric field perpendicular to the flow and the magnetic field that accelerates the background ions radially outward, which in turn causes the speedup of the pulse. With electric and magnetic field probes, the UCLA laser experiments should be able to detect these signatures of coupling as well as the generation of the shock wave.

  3. Axion decay and anisotropy of near-IR extragalactic background light

    E-Print Network [OSTI]

    Gong, Yan; Mitchell-Wynne, Ketron; Chen, Xuelei; Zemcov, Michael; Smidt, Joseph

    2015-01-01

    The extragalactic background light is expected to be comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of radiation. An example is the intra-halo light, associated with diffuse stars in dark matter halos resulting from galaxy mergers and tidal interactions, identified based on measurements involving the angular power spectrum of infrared background anisotropies. The angular power spectra of the near-infrared intensities could still contain additional signals and a complete understanding of the nature of the IR background is still lacking in the literature. Here we explore the constraints that can be placed on the decay products associated with particle decays, especially candidate dark matter models involving axions that trace dark matter halos of galaxies. Axions with a mass around a few eV will decay via two photons with wavelengths in the near-IR band, and will leave a ...

  4. Ship Effect Neutron Measurements And Impacts On Low-Background Experiments

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

    2013-10-01

    The primary particles entering the upper atmosphere as cosmic rays create showers in the atmosphere that include a broad spectrum of secondary neutrons, muons and protons. These cosmic-ray secondaries interact with materials at the surface of the Earth, yielding prompt backgrounds in radiation detection systems, as well as inducing long-lived activities through spallation events, dominated by the higher-energy neutron secondaries. For historical reasons, the multiple neutrons produced in spallation cascade events are referred to as “ship effect” neutrons. Quantifying the background from cosmic ray induced activities is important to low-background experiments, such as neutrino-less double beta decay. Since direct measurements of the effects of shielding on the cosmic-ray neutron spectrum are not available, Monte Carlo modeling is used to compute such effects. However, there are large uncertainties (orders of magnitude) in the possible cross-section libraries and the cosmic-ray neutron spectrum for the energy range needed in such calculations. The measurements reported here were initiated to validate results from Monte Carlo models through experimental measurements in order to provide some confidence in the model results. The results indicate that the models provide the correct trends of neutron production with increasing density, but there is substantial disagreement between the model and experimental results for the lower-density materials of Al, Fe and Cu.

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

    E-Print Network [OSTI]

    Edlund, J A; Królak, A; Nelemans, G; Edlund, Jeffrey A.; Tinto, Massimo; Krolak, Andrzej; Nelemans, Gijs

    2005-01-01

    LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low-part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. Since the galactic white-dwarfs background will be observed by LISA not as a stationary but rather as a cyc...

  6. Simulation of the White Dwarf -- White Dwarf galactic background in the LISA data

    E-Print Network [OSTI]

    Edlund, J A; Królak, A; Nelemans, G; Edlund, Jeffrey A.; Tinto, Massimo; Kr\\'olak, Andrzej; Nelemans, Gijs

    2005-01-01

    LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low-part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. Since the galactic white-dwarfs background will be observed by LISA not as a stationary but rather as a cyc...

  7. Calibration of an ultra-low-background proportional counter for measuring {sup 37}Ar

    SciTech Connect (OSTI)

    Seifert, A.; Aalseth, C. E.; Bonicalzi, R. M.; Bowyer, T. W.; Day, A. R.; Fuller, E. S.; Haas, D. A.; Hayes, J. C.; Hoppe, E. W.; Humble, P. H.; Keillor, M. E.; LaFerriere, B. D.; Mace, E. K.; McIntyre, J. I.; Merriman, J. H.; Miley, H. S.; Myers, A. W.; Orrell, J. L.; Overman, C. T.; Panisko, M. E. [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99352 (United States)] [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99352 (United States); and others

    2013-08-08

    An ultra-low-background proportional counter design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electro-chemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with {sup 14}C/{sup 3}H, age-dating of groundwater with {sup 39}Ar, and soil-gas assay for {sup 37}Ar to support On-Site Inspection (OSI). On-Site Inspection is a key component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of {sup 37}Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of {sup 37}Ar samples over a broad range of proportional counter operating pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for {sup 37}Ar soil gas background studies.

  8. Phase-coherent mapping of gravitational-wave backgrounds using ground-based laser interferometers

    E-Print Network [OSTI]

    Joseph D. Romano; Stephen R. Taylor; Neil J. Cornish; Jonathan Gair; Chiara M. F. Mingarelli; Rutger van Haasteren

    2015-05-27

    We extend the formalisms developed in Gair et al. and Cornish and van Haasteren to create maps of gravitational-wave backgrounds using a network of ground-based laser interferometers. We show that in contrast to pulsar timing arrays, which are insensitive to half of the gravitational-wave sky (the curl modes), a network of ground-based interferometers is sensitive to both the gradient and curl components of the background. The spatial separation of a network of interferometers, or of a single interferometer at different times during its rotational and orbital motion around the Sun, allows for recovery of both components. We derive expressions for the response functions of a laser interferometer in the small-antenna limit, and use these expressions to calculate the overlap reduction function for a pair of interferometers. We also construct maximum-likelihood estimates of the + and x-polarization modes of the gravitational-wave sky in terms of the response matrix for a network of ground-based interferometers, evaluated at discrete times during Earth's rotational and orbital motion around the Sun. We demonstrate the feasibility of this approach for some simple simulated backgrounds (a single point source and spatially-extended distributions having only grad or curl components), calculating maximum-likelihood sky maps and uncertainty maps based on the (pseudo)inverse of the response matrix. The distinction between this approach and standard methods for mapping gravitational-wave power is also discussed.

  9. The Majorana low-noise low-background front-end electronics

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

    Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; et al

    2015-03-24

    The Majorana Demonstrator will search for the neutrinoless double beta decay (??(0?)) of the isotope ??Ge with a mixed array of enriched and natural germanium detectors. In view of the next generation of tonne-scale germanium-based ??(0?)-decay searches, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039-keV Q-value of the ??Ge ??(0?)-decay. Such a requirement on the background level significantly constrains the design of the readout electronics, which is further driven by noise and energy resolutionmore »performances. We present here the low-noise low-background front-end electronics developed for the low-capacitance p-type point contact (P-PC) germanium detectors of the Majorana Demonstrator. This resistive-feedback front-end, specifically designed to have low mass, is fabricated on a radioassayed fused-silica substrate where the feedback resistor consists of a sputtered thin film of high purity amorphous germanium and the feedback capacitor is based on the capacitance between gold conductive traces.« less

  10. NEW OBSERVATION OF FAILED FILAMENT ERUPTIONS: THE INFLUENCE OF ASYMMETRIC CORONAL BACKGROUND FIELDS ON SOLAR ERUPTIONS

    SciTech Connect (OSTI)

    Liu, Y.; Xu, Z.; Su, J.; Lin, H.; Shibata, K.; Kurokawa, H.

    2009-05-01

    Failed filament eruptions not associated with a coronal mass ejection (CME) have been observed and reported as evidence for solar coronal field confinement on erupting flux ropes. In those events, each filament eventually returns to its origin on the solar surface. In this Letter, a new observation of two failed filament eruptions is reported which indicates that the mass of a confined filament can be ejected to places far from the original filament channel. The jetlike mass motions in the two failed filament eruptions are thought to be due to the asymmetry of the background coronal magnetic fields with respect to the locations of the filament channels. The asymmetry of the coronal fields is confirmed by an extrapolation based on a potential field model. The obvious imbalance between the positive and negative magnetic flux (with a ratio of 1:3) in the bipolar active region is thought to be the direct cause of the formation of the asymmetric coronal fields. We think that the asymmetry of the background fields can not only influence the trajectories of ejecta, but also provide a relatively stronger confinement for flux rope eruptions than the symmetric background fields do.

  11. The Majorana low-noise low-background front-end electronics

    SciTech Connect (OSTI)

    Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, III, F. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of South Carolina, Columbia, SC (United States); Barabash, A. S. [Institute for Theoretical and Experiemental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Durham, NC (United States); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Durham, NC (United States); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Durham, NC (United States); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); North Carolina State Univ., Raleigh, NC (United States); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Durham, NC (United States); Konovalov, S. I. [Institute for Theoretical and Experiemental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ., Shanghai (China); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States)

    2015-01-01

    The Majorana Demonstrator will search for the neutrinoless double beta decay (??(0?)) of the isotope ??Ge with a mixed array of enriched and natural germanium detectors. In view of the next generation of tonne-scale germanium-based ??(0?)-decay searches, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039-keV Q-value of the ??Ge ??(0?)-decay. Such a requirement on the background level significantly constrains the design of the readout electronics, which is further driven by noise and energy resolution performances. We present here the low-noise low-background front-end electronics developed for the low-capacitance p-type point contact (P-PC) germanium detectors of the Majorana Demonstrator. This resistive-feedback front-end, specifically designed to have low mass, is fabricated on a radioassayed fused-silica substrate where the feedback resistor consists of a sputtered thin film of high purity amorphous germanium and the feedback capacitor is based on the capacitance between gold conductive traces.

  12. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    SciTech Connect (OSTI)

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.A.; Startsev, E.A.; Sefkow, A.B; Friedman, A.F.; Lee, E.P.

    2009-09-03

    Neutralization and focusing of intense charged particle beam pulses by a background plasma forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the background plasma. If controlled, this physical effect can be used for optimized beam transport over long distances.

  13. LY? FOREST TOMOGRAPHY FROM BACKGROUND GALAXIES: THE FIRST MEGAPARSEC-RESOLUTION LARGE-SCALE STRUCTURE MAP AT z > 2

    SciTech Connect (OSTI)

    Lee, Khee-Gan; Hennawi, Joseph F.; Eilers, Anna-Christina [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Stark, Casey; White, Martin [Department of Astronomy, University of California at Berkeley, B-20 Hearst Field Annex 3411, Berkeley, CA 94720 (United States); Prochaska, J. Xavier [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Schlegel, David J. [University of California Observatories, Lick Observatory, 1156 High Street, Santa Cruz, CA 95064 (United States); Arinyo-i-Prats, Andreu [Institut de Ciències del Cosmos, Universitat de Barcelona (IEEC-UB), Martí Franquès 1, E-08028 Barcelona (Spain); Suzuki, Nao [Kavli Institute for the Physics and Mathematics of the Universe (IPMU), The University of Tokyo, Kashiwano-ha 5-1-5, Kashiwa-shi, Chiba (Japan); Croft, Rupert A. C. [Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Caputi, Karina I. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700-AV Groningen (Netherlands); Cassata, Paolo [Instituto de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Casilla 5030, Valparaiso (Chile); Ilbert, Olivier; Le Brun, Vincent; Le Fèvre, Olivier [Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Garilli, Bianca [INAF-IASF, Via Bassini 15, I-20133, Milano (Italy); Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Maccagni, Dario [INAF-Osservatorio Astronomico di Bologna, Via Ranzani,1, I-40127 Bologna (Italy); Nugent, Peter, E-mail: lee@mpia.de [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); and others

    2014-11-01

    We present the first observations of foreground Ly? forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with z ? 2.3-2.8 within a 5' × 14' region of the COSMOS field. The transverse sightline separation is ?2 h {sup –1} Mpc comoving, allowing us to create a tomographic reconstruction of the three-dimensional (3D) Ly? forest absorption field over the redshift range 2.20 ? z ? 2.45. The resulting map covers 6 h {sup –1} Mpc × 14 h {sup –1} Mpc in the transverse plane and 230 h {sup –1} Mpc along the line of sight with a spatial resolution of ?3.5 h {sup –1} Mpc, and is the first high-fidelity map of a large-scale structure on ?Mpc scales at z > 2. Our map reveals significant structures with ? 10 h {sup –1} Mpc extent, including several spanning the entire transverse breadth, providing qualitative evidence for the filamentary structures predicted to exist in the high-redshift cosmic web. Simulated reconstructions with the same sightline sampling, spectral resolution, and signal-to-noise ratio recover the salient structures present in the underlying 3D absorption fields. Using data from other surveys, we identified 18 galaxies with known redshifts coeval with our map volume, enabling a direct comparison with our tomographic map. This shows that galaxies preferentially occupy high-density regions, in qualitative agreement with the same comparison applied to simulations. Our results establish the feasibility of the CLAMATO survey, which aims to obtain Ly? forest spectra for ?1000 SFGs over ?1 deg{sup 2} of the COSMOS field, in order to map out the intergalactic medium large-scale structure at (z) ? 2.3 over a large volume (100 h {sup –1} Mpc){sup 3}.

  14. BEAVER DISTRIBUTION 233 CM. Fish ,md Cime 75(4): 233-238 1 989

    E-Print Network [OSTI]

    Beier, Paul

    . tremuloides, willow, Salix spp, and alder, Ainus incana, were the most heavily used woody forage species tremuloides, cottonwood, P. trichocarpa, willow, Salix spp., mountain alder, AInus incana, gray dogwood

  15. Coupled Stokes-Darcy Model with Beavers-Joseph Interface Boundary Condition

    E-Print Network [OSTI]

    porosity. However, underground fissures and conduits and surface sinkholes and springs play a major role

  16. Geology and Geothermal Potential of the Roosevelt Hot Springs Area, Beaver

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable UrbanKentucky: EnergyGateway1997) | OpenRaft river valley, IdahoCounty,

  17. Beaver County, Oklahoma ASHRAE 169-2006 Climate Zone | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAE 169-2006Parish,Beaux

  18. Beaver County, Utah ASHRAE 169-2006 Climate Zone | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformation Beaufort County, South Carolina ASHRAEInformationUtah ASHRAE

  19. ForCent model development and testing using the Enriched Background Isotope Study experiment

    SciTech Connect (OSTI)

    Parton, W.J.; Hanson, P. J.; Swanston, C.; Torn, M.; Trumbore, S. E.; Riley, W.; Kelly, R.

    2010-10-01

    The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool {sup 14}C signature ({Delta} {sup 14}C) data from the Enriched Background Isotope Study {sup 14}C experiment (1999-2006) shows that the model correctly simulates the temporal dynamics of the {sup 14}C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass {Delta} {sup 14}C data, and with soil respiration {Delta} {sup 14}C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study {sup 14}C experimental treatments on soil respiration {Delta} {sup 14}C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.

  20. The formation of massive primordial stars in the presence of moderate UV backgrounds

    SciTech Connect (OSTI)

    Latif, M. A.; Schleicher, D. R. G.; Bovino, S. [Institut für Astrophysik, Georg-August-Universität, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany); Grassi, T. [Centre for Star and Planet Formation, Natural History Museum of Denmark, Øster Voldgade 5-7, DK-1350 Copenhagen (Denmark); Spaans, M., E-mail: mlatif@astro.physik.uni-goettingen.de [Kapteyn Astronomical Institute, University of Groningen, 9700-AV Groningen (Netherlands)

    2014-09-01

    Radiative feedback produced by stellar populations played a vital role in early structure formation. In particular, photons below the Lyman limit can escape the star-forming regions and produce a background ultraviolet (UV) flux, which consequently may influence the pristine halos far away from the radiation sources. These photons can quench the formation of molecular hydrogen by photodetachment of H{sup –}. In this study, we explore the impact of such UV radiation on fragmentation in massive primordial halos of a few times 10{sup 7} M {sub ?}. To accomplish this goal, we perform high resolution cosmological simulations for two distinct halos and vary the strength of the impinging background UV field in units of J {sub 21} assuming a blackbody radiation spectrum with a characteristic temperature of T {sub rad} = 10{sup 4} K. We further make use of sink particles to follow the evolution for 10,000 yr after reaching the maximum refinement level. No vigorous fragmentation is observed in UV-illuminated halos while the accretion rate changes according to the thermal properties. Our findings show that a few 10{sup 2}-10{sup 4} solar mass protostars are formed when halos are irradiated by J {sub 21} = 10-500 at z > 10 and suggest a strong relation between the strength of the UV flux and mass of a protostar. This mode of star formation is quite different from minihalos, as higher accretion rates of about 0.01-0.1 M {sub ?} yr{sup –1} are observed by the end of our simulations. The resulting massive stars are potential cradles for the formation of intermediate-mass black holes at earlier cosmic times and contribute to the formation of a global X-ray background.

  1. Strings in Background Electric Field, Space/Time Noncommutativity and A New Noncritical String Theory

    E-Print Network [OSTI]

    N. Seiberg; L. Susskind; N. Toumbas

    2000-05-04

    Searching for space/time noncommutativity we reconsider open strings in a constant background electric field. The main difference between this situation and its magnetic counterpart is that here there is a critical electric field beyond which the theory does not make sense. We show that this critical field prevents us from finding a limit in which the theory becomes a field theory on a noncommutative spacetime. However, an appropriate limit toward the critical field leads to a novel noncritical string theory on a noncommutative spacetime.

  2. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    SciTech Connect (OSTI)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.

    1982-06-01

    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  3. Bounds for scalar waves on self-similar naked-singularity backgrounds

    E-Print Network [OSTI]

    Brien C. Nolan

    2006-06-19

    The stability of naked singularities in self-similar collapse is probed using scalar waves. It is shown that the multipoles of a minimally coupled massless scalar field propagating on a spherically symmetric self-similar background spacetime admitting a naked singularity maintain finite $L^2$ norm as they impinge on the Cauchy horizon. It is also shown that each multipole obeys a pointwise bound at the horizon, as does its locally observed energy density. $L^2$ and pointwise bounds are also obtained for the multipoles of a minimally coupled massive scalar wave packet.

  4. Investigations of 2? decay measured by low background HPGe spectrometer OBELIX

    SciTech Connect (OSTI)

    Rukhadze, Ekaterina [Institute of Experimental and Applied Physics, CTU in Prague, Horska 3a Collaboration: OBELIX Collaboration; SuperNEMO Collaboration

    2013-12-30

    A low background high sensitive HPGe spectrometer OBELIX was installed at the Modane Underground Laboratory (LSM, France, 4800 m w.e.). The detector was designed to measure a contamination of enriched isotopes and radio-impurities in construction materials, to investigate rare nuclear processes such as resonance neutrinoless double electron capture and two-neutrino double beta decay to excited states of daughter nuclei. Spectrometer sensitivity, contamination of NEMO-3 sources and results of 2?2?{sup ?} decay of {sup 100}Mo to the 0{sup +} (1130 keV) and 2{sup +} (540 keV) excited states as well as future plans for OBELIX detector are given.

  5. Hanford Waste Vitrification Plant technical background document for best available radionuclide control technology demonstration

    SciTech Connect (OSTI)

    Carpenter, A.B.; Skone, S.S.; Rodenhizer, D.G.; Marusich, M.V. (Ebasco Services, Inc., Bellevue, WA (USA))

    1990-10-01

    This report provides the background documentation to support applications for approval to construct and operate new radionuclide emission sources at the Hanford Waste Vitrification Plant (HWVP) near Richland, Washington. The HWVP is required to obtain permits under federal and state statutes for atmospheric discharges of radionuclides. Since these permits must be issued prior to construction of the facility, draft permit applications are being prepared, as well as documentation to support these permits. This report addresses the applicable requirements and demonstrates that the preferred design meets energy, environmental, and economic criteria for Best Available Radionuclide Control Technology (BARCT) at HWVP. 22 refs., 11 figs., 25 tabs.

  6. Probability Density of the Multipole Vectors for a Gaussian Cosmic Microwave Background

    E-Print Network [OSTI]

    Mark R. Dennis; Kate Land

    2007-08-09

    We review Maxwell's multipole vectors, and elucidate some of their mathematical properties, with emphasis on the application of this tool to the cosmic microwave background (CMB). In particular, for a completely random function on the sphere (corresponding to the statistically isotropic Gaussian model of the CMB), we derive the full probability density function of the multipole vectors. This function is used to analyze the internal configurations of the third-year Wilkinson Microwave Anisotropy Probe quadrupole and octopole, and we show the observations are consistent with the Gaussian prediction. A particular aspect is the planarity of the octopole, which we find not to be anomalous.

  7. Wave breaking phenomenon of lower-hybrid oscillations induced by a background inhomogeneous magnetic field

    SciTech Connect (OSTI)

    Maity, Chandan; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sengupta, Sudip [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2012-10-15

    In a fluid description, we study space-time evolution of lower hybrid modes in a cold quasi-neutral homogeneous plasma in presence of a background inhomogeneous magnetic field. Within a linear analysis, a dispersion relation with inhomogeneous magnetic field shows 'phase mixing' of such oscillations. A manifestation of 'phase mixing' is shown in 'mode coupling.' By using Lagrangian variables, an exact solution is presented in parametric form of this nonlinear time dependent problem. It is demonstrated that initially excited lower hybrid modes always break via phase mixing phenomenon in presence of an inhomogeneous magnetic field. Breaking of such oscillations is revealed by the appearance of spikes in the plasma density profile.

  8. Background and Derivation of ANS-5.4 Standard Fission Product Release Model

    SciTech Connect (OSTI)

    Beyer, Carl E.; Turnbull, Andrew J.

    2010-01-29

    This background report describes the technical basis for the newly proposed American Nuclear Society (ANS) 5.4 standard, Methods for Calculating the Fractional Release of Volatile Fission Products from Oxide Fuels. The proposed ANS 5.4 standard provides a methodology for determining the radioactive fission product releases from the fuel for use in assessing radiological consequences of postulated accidents that do not involve abrupt power transients. When coupled with isotopic yields, this method establishes the 'gap activity,' which is the inventory of volatile fission products that are released from the fuel rod if the cladding are breached.

  9. Measurement of background gas in paraffin-coated alkali vapor cells

    E-Print Network [OSTI]

    Sekiguchi, Naota

    2015-01-01

    We measured the rate of velocity-changing collisions (VCCs) between alkali atoms and background gas in buffer-gas-free anti-spin-relaxation-coated cells. The average VCC rate in paraffin-coated rubidium vapor cells prepared in this work was $1 \\times 10^{6}$ s$^{-1}$, which corresponds to $\\sim$1 mm in the mean free path of rubidium atoms. This short mean free path indicates that alkali atoms do not travel freely between the cell walls. In addition, we found that a heating process known as "ripening" increases the VCC rate, and also confirmed that ripening improves the anti-relaxation performance of the coatings.

  10. A simulation-based study of the neutron backgrounds for NaI dark matter experiments

    E-Print Network [OSTI]

    Eunju Jeon; Yeongduk Kim

    2015-03-26

    Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.

  11. A simulation-based study of the neutron backgrounds for NaI dark matter experiments

    E-Print Network [OSTI]

    Jeon, Eunju

    2015-01-01

    Among the direct search experiments for weakly interacting massive particle (WIMP) dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with a significance of 9.2$\\sigma$. Recently, Jonathan Davis claimed that the DAMA modulation may be interpreted on the basis of the neutron scattering events induced by the muons and neutrinos together. We tried to simulate the neutron backgrounds at the Gran Sasso and Yangyang laboratory with and without the polyethylene shielding to quantify the effects of the ambient neutrons on the direct detection experiments based on the crystals.

  12. Background Information for the Nevada National Security Site Integrated Sampling Plan, Revision 0

    SciTech Connect (OSTI)

    Farnham, Irene; Marutzky, Sam

    2014-12-01

    This document describes the process followed to develop the Nevada National Security Site (NNSS) Integrated Sampling Plan (referred to herein as the Plan). It provides the Plan’s purpose and objectives, and briefly describes the Underground Test Area (UGTA) Activity, including the conceptual model and regulatory requirements as they pertain to groundwater sampling. Background information on other NNSS groundwater monitoring programs—the Routine Radiological Environmental Monitoring Plan (RREMP) and Community Environmental Monitoring Program (CEMP)—and their integration with the Plan are presented. Descriptions of the evaluations, comments, and responses of two Sampling Plan topical committees are also included.

  13. The Three-String Vertex for a Plane-Wave Background

    E-Print Network [OSTI]

    John H. Schwarz

    2003-12-23

    The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background can be constructed in a light-cone gauge string field theory formalism. The detailed formula contains certain Neumann coefficients, which are functions of a momentum fraction y and a mass parameter \\mu. This paper reviews the derivation of useful explicit expressions for these Neumann coefficients generalizing flat-space (\\mu = 0) results obtained long ago. These expressions are then used to explore the large \\mu asymptotic behavior, which is required for comparison with dual perturbative gauge theory results. The asymptotic formulas, exact up to exponentially small corrections, turn out to be surprisingly simple.

  14. AES NewEnergy, Inc. Order No. EA-248 I. BACKGROUND

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De p u t y A s s iof1 ofDensifiedDepartmentDepartmentI. BACKGROUND

  15. Introduction/Motivation Background/Notation Classification Results/Future Work/References Classifying Pairs of Fuchsian Groups

    E-Print Network [OSTI]

    Broughton, S. Allen

    Introduction/Motivation Background/Notation Classification Results/Future Work Regional Meeting at University of Tucson April 2007 #12;Introduction/Motivation Background/Notation Classification Results/Future Work/References Outline 1 Introduction/Motivation Motivation 1 - extension

  16. Global causal propagator for the KleinGordon equation on a class of supersymmetric AdS backgrounds

    E-Print Network [OSTI]

    Enciso, Alberto

    Global causal propagator for the Klein­Gordon equation on a class of supersymmetric AdS backgrounds analyze the Cauchy problem for the Klein­Gordon equation on the type IIB super- gravity backgrounds AdS5 of their connections to the AdS/CFT correspon- dence [2]. More precisely, if Y is a Sasaki­Einstein 5-manifold

  17. A study on the background and clustering seismicity in the Taiwan region by using point process models

    E-Print Network [OSTI]

    Chen, Yuh-Ing

    A study on the background and clustering seismicity in the Taiwan region by using point process), A study on the background and clustering seismicity in the Taiwan region by using point process models, J the shallow seismicity occurring in the Taiwan region during the 20th century using a stochastic declustering

  18. Tangential force, Frictional Torque and Heating Rate of a Small Neutral Rotating Particle Moving through the Equilibrium Background Radiation

    E-Print Network [OSTI]

    G. V. Dedkov; A. A. Kyasov

    2013-02-04

    For the first time, based on the fluctuation-electromagnetic theory, we have calculated the drug force, the radiation heat flux and the frictional torque on a small rotating particle moving at a relativistic velocity through the equilibrium background radiation (photon gas). The particle and background radiation are characterized by different temperatures corresponding to the local thermodynamic equilibrium in their own reference frames.

  19. Effects of 20002050 changes in climate and emissions on global tropospheric ozone and the policy-relevant background surface ozone

    E-Print Network [OSTI]

    Wu, Shiliang

    Effects of 2000­2050 changes in climate and emissions on global tropospheric ozone and the policy-relevant background surface ozone in the United States Shiliang Wu,1 Loretta J. Mickley,1 Daniel J. Jacob,1 David Rind) on the global tropospheric ozone budget and on the policy-relevant background (PRB) ozone in the United States

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

    SciTech Connect (OSTI)

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

    2014-11-01

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